OAuth2スコープ

FastAPIではOAuth2スコープを直接使用でき、シームレスに連携するように統合されています。

これにより、OAuth2標準に従った、よりきめ細やかなパーミッションシステムを、OpenAPIアプリケーション（およびAPIドキュメント）に統合することができます。

スコープ付きOAuth2は、Facebook、Google、GitHub、Microsoft、X (Twitter) などの多くの大手認証プロバイダーが使用しているメカニズムです。これらは、ユーザーとアプリケーションに特定のパーミッションを提供するために使用されます。

Facebook、Google、GitHub、Microsoft、X (Twitter) で「ログイン」するたびに、そのアプリケーションはスコープ付きOAuth2を使用しています。

このセクションでは、FastAPIアプリケーションで同じスコープ付きOAuth2を使用して認証と認可を管理する方法を説明します。

Warning

これは多かれ少なかれ高度なセクションです。始めたばかりの場合はスキップしても構いません。

必ずしもOAuth2スコープが必要なわけではなく、認証と認可は好きなように処理できます。

しかし、スコープ付きOAuth2はAPI（OpenAPIを使用）とAPIドキュメントにうまく統合できます。

それでも、コードで必要に応じて、それらのスコープやその他のセキュリティ/認可要件を強制する必要があります。

多くの場合、スコープ付きOAuth2は過剰かもしれません。

しかし、それがあなたにとって必要だとわかっている場合、または興味がある場合は、読み進めてください。

OAuth2スコープとOpenAPI

OAuth2仕様では、「スコープ」をスペースで区切られた文字列のリストとして定義しています。

これらの各文字列の内容は任意の形式にできますが、スペースを含めるべきではありません。

これらのスコープは「パーミッション」を表します。

OpenAPI（例：APIドキュメント）では、「セキュリティスキーム」を定義できます。

これらのセキュリティスキームのいずれかがOAuth2を使用している場合、スコープも宣言して使用できます。

各「スコープ」は単なる文字列（スペースなし）です。

これらは通常、特定のセキュリティパーミッションを宣言するために使用されます。例えば、

• users:readやusers:writeは一般的な例です。
• instagram_basicはFacebook / Instagramによって使用されます。
• https://www.googleapis.com/auth/driveはGoogleによって使用されます。

情報

OAuth2では、「スコープ」は必要な特定のパーミッションを宣言する単なる文字列です。

:のような他の文字が含まれていても、URLであっても関係ありません。

これらの詳細は実装固有です。

OAuth2にとって、それらは単なる文字列です。

全体像

まず、メインのチュートリアル - ユーザーガイドのパスワード付きOAuth2 (およびハッシュ化)、JWTトークン付きベアラーの例からの変更点をざっと見てみましょう。今回はOAuth2スコープを使用します

Python 3.10+

from datetime import datetime, timedelta, timezone
from typing import Annotated

import jwt
from fastapi import Depends, FastAPI, HTTPException, Security, status
from fastapi.security import (
    OAuth2PasswordBearer,
    OAuth2PasswordRequestForm,
    SecurityScopes,
)
from jwt.exceptions import InvalidTokenError
from pwdlib import PasswordHash
from pydantic import BaseModel, ValidationError

# to get a string like this run:
# openssl rand -hex 32
SECRET_KEY = "09d25e094faa6ca2556c818166b7a9563b93f7099f6f0f4caa6cf63b88e8d3e7"
ALGORITHM = "HS256"
ACCESS_TOKEN_EXPIRE_MINUTES = 30


fake_users_db = {
    "johndoe": {
        "username": "johndoe",
        "full_name": "John Doe",
        "email": "johndoe@example.com",
        "hashed_password": "$argon2id$v=19$m=65536,t=3,p=4$wagCPXjifgvUFBzq4hqe3w$CYaIb8sB+wtD+Vu/P4uod1+Qof8h+1g7bbDlBID48Rc",
        "disabled": False,
    },
    "alice": {
        "username": "alice",
        "full_name": "Alice Chains",
        "email": "alicechains@example.com",
        "hashed_password": "$argon2id$v=19$m=65536,t=3,p=4$g2/AV1zwopqUntPKJavBFw$BwpRGDCyUHLvHICnwijyX8ROGoiUPwNKZ7915MeYfCE",
        "disabled": True,
    },
}


class Token(BaseModel):
    access_token: str
    token_type: str


class TokenData(BaseModel):
    username: str | None = None
    scopes: list[str] = []


class User(BaseModel):
    username: str
    email: str | None = None
    full_name: str | None = None
    disabled: bool | None = None


class UserInDB(User):
    hashed_password: str


password_hash = PasswordHash.recommended()

oauth2_scheme = OAuth2PasswordBearer(
    tokenUrl="token",
    scopes={"me": "Read information about the current user.", "items": "Read items."},
)

app = FastAPI()


def verify_password(plain_password, hashed_password):
    return password_hash.verify(plain_password, hashed_password)


def get_password_hash(password):
    return password_hash.hash(password)


def get_user(db, username: str):
    if username in db:
        user_dict = db[username]
        return UserInDB(**user_dict)


def authenticate_user(fake_db, username: str, password: str):
    user = get_user(fake_db, username)
    if not user:
        return False
    if not verify_password(password, user.hashed_password):
        return False
    return user


def create_access_token(data: dict, expires_delta: timedelta | None = None):
    to_encode = data.copy()
    if expires_delta:
        expire = datetime.now(timezone.utc) + expires_delta
    else:
        expire = datetime.now(timezone.utc) + timedelta(minutes=15)
    to_encode.update({"exp": expire})
    encoded_jwt = jwt.encode(to_encode, SECRET_KEY, algorithm=ALGORITHM)
    return encoded_jwt


async def get_current_user(
    security_scopes: SecurityScopes, token: Annotated[str, Depends(oauth2_scheme)]
):
    if security_scopes.scopes:
        authenticate_value = f'Bearer scope="{security_scopes.scope_str}"'
    else:
        authenticate_value = "Bearer"
    credentials_exception = HTTPException(
        status_code=status.HTTP_401_UNAUTHORIZED,
        detail="Could not validate credentials",
        headers={"WWW-Authenticate": authenticate_value},
    )
    try:
        payload = jwt.decode(token, SECRET_KEY, algorithms=[ALGORITHM])
        username = payload.get("sub")
        if username is None:
            raise credentials_exception
        scope: str = payload.get("scope", "")
        token_scopes = scope.split(" ")
        token_data = TokenData(scopes=token_scopes, username=username)
    except (InvalidTokenError, ValidationError):
        raise credentials_exception
    user = get_user(fake_users_db, username=token_data.username)
    if user is None:
        raise credentials_exception
    for scope in security_scopes.scopes:
        if scope not in token_data.scopes:
            raise HTTPException(
                status_code=status.HTTP_401_UNAUTHORIZED,
                detail="Not enough permissions",
                headers={"WWW-Authenticate": authenticate_value},
            )
    return user


async def get_current_active_user(
    current_user: Annotated[User, Security(get_current_user, scopes=["me"])],
):
    if current_user.disabled:
        raise HTTPException(status_code=400, detail="Inactive user")
    return current_user


@app.post("/token")
async def login_for_access_token(
    form_data: Annotated[OAuth2PasswordRequestForm, Depends()],
) -> Token:
    user = authenticate_user(fake_users_db, form_data.username, form_data.password)
    if not user:
        raise HTTPException(status_code=400, detail="Incorrect username or password")
    access_token_expires = timedelta(minutes=ACCESS_TOKEN_EXPIRE_MINUTES)
    access_token = create_access_token(
        data={"sub": user.username, "scope": " ".join(form_data.scopes)},
        expires_delta=access_token_expires,
    )
    return Token(access_token=access_token, token_type="bearer")


@app.get("/users/me/", response_model=User)
async def read_users_me(
    current_user: Annotated[User, Depends(get_current_active_user)],
):
    return current_user


@app.get("/users/me/items/")
async def read_own_items(
    current_user: Annotated[User, Security(get_current_active_user, scopes=["items"])],
):
    return [{"item_id": "Foo", "owner": current_user.username}]


@app.get("/status/")
async def read_system_status(current_user: Annotated[User, Depends(get_current_user)]):
    return {"status": "ok"}

🤓 その他のバージョンとバリアント

Python 3.9+Python 3.8+Python 3.10+ - non-AnnotatedPython 3.9+ - 非注釈付きPython 3.8+ - non-Annotated

from datetime import datetime, timedelta, timezone
from typing import Annotated, Union

import jwt
from fastapi import Depends, FastAPI, HTTPException, Security, status
from fastapi.security import (
    OAuth2PasswordBearer,
    OAuth2PasswordRequestForm,
    SecurityScopes,
)
from jwt.exceptions import InvalidTokenError
from pwdlib import PasswordHash
from pydantic import BaseModel, ValidationError

# to get a string like this run:
# openssl rand -hex 32
SECRET_KEY = "09d25e094faa6ca2556c818166b7a9563b93f7099f6f0f4caa6cf63b88e8d3e7"
ALGORITHM = "HS256"
ACCESS_TOKEN_EXPIRE_MINUTES = 30


fake_users_db = {
    "johndoe": {
        "username": "johndoe",
        "full_name": "John Doe",
        "email": "johndoe@example.com",
        "hashed_password": "$argon2id$v=19$m=65536,t=3,p=4$wagCPXjifgvUFBzq4hqe3w$CYaIb8sB+wtD+Vu/P4uod1+Qof8h+1g7bbDlBID48Rc",
        "disabled": False,
    },
    "alice": {
        "username": "alice",
        "full_name": "Alice Chains",
        "email": "alicechains@example.com",
        "hashed_password": "$argon2id$v=19$m=65536,t=3,p=4$g2/AV1zwopqUntPKJavBFw$BwpRGDCyUHLvHICnwijyX8ROGoiUPwNKZ7915MeYfCE",
        "disabled": True,
    },
}


class Token(BaseModel):
    access_token: str
    token_type: str


class TokenData(BaseModel):
    username: Union[str, None] = None
    scopes: list[str] = []


class User(BaseModel):
    username: str
    email: Union[str, None] = None
    full_name: Union[str, None] = None
    disabled: Union[bool, None] = None


class UserInDB(User):
    hashed_password: str


password_hash = PasswordHash.recommended()

oauth2_scheme = OAuth2PasswordBearer(
    tokenUrl="token",
    scopes={"me": "Read information about the current user.", "items": "Read items."},
)

app = FastAPI()


def verify_password(plain_password, hashed_password):
    return password_hash.verify(plain_password, hashed_password)


def get_password_hash(password):
    return password_hash.hash(password)


def get_user(db, username: str):
    if username in db:
        user_dict = db[username]
        return UserInDB(**user_dict)


def authenticate_user(fake_db, username: str, password: str):
    user = get_user(fake_db, username)
    if not user:
        return False
    if not verify_password(password, user.hashed_password):
        return False
    return user


def create_access_token(data: dict, expires_delta: Union[timedelta, None] = None):
    to_encode = data.copy()
    if expires_delta:
        expire = datetime.now(timezone.utc) + expires_delta
    else:
        expire = datetime.now(timezone.utc) + timedelta(minutes=15)
    to_encode.update({"exp": expire})
    encoded_jwt = jwt.encode(to_encode, SECRET_KEY, algorithm=ALGORITHM)
    return encoded_jwt


async def get_current_user(
    security_scopes: SecurityScopes, token: Annotated[str, Depends(oauth2_scheme)]
):
    if security_scopes.scopes:
        authenticate_value = f'Bearer scope="{security_scopes.scope_str}"'
    else:
        authenticate_value = "Bearer"
    credentials_exception = HTTPException(
        status_code=status.HTTP_401_UNAUTHORIZED,
        detail="Could not validate credentials",
        headers={"WWW-Authenticate": authenticate_value},
    )
    try:
        payload = jwt.decode(token, SECRET_KEY, algorithms=[ALGORITHM])
        username = payload.get("sub")
        if username is None:
            raise credentials_exception
        scope: str = payload.get("scope", "")
        token_scopes = scope.split(" ")
        token_data = TokenData(scopes=token_scopes, username=username)
    except (InvalidTokenError, ValidationError):
        raise credentials_exception
    user = get_user(fake_users_db, username=token_data.username)
    if user is None:
        raise credentials_exception
    for scope in security_scopes.scopes:
        if scope not in token_data.scopes:
            raise HTTPException(
                status_code=status.HTTP_401_UNAUTHORIZED,
                detail="Not enough permissions",
                headers={"WWW-Authenticate": authenticate_value},
            )
    return user


async def get_current_active_user(
    current_user: Annotated[User, Security(get_current_user, scopes=["me"])],
):
    if current_user.disabled:
        raise HTTPException(status_code=400, detail="Inactive user")
    return current_user


@app.post("/token")
async def login_for_access_token(
    form_data: Annotated[OAuth2PasswordRequestForm, Depends()],
) -> Token:
    user = authenticate_user(fake_users_db, form_data.username, form_data.password)
    if not user:
        raise HTTPException(status_code=400, detail="Incorrect username or password")
    access_token_expires = timedelta(minutes=ACCESS_TOKEN_EXPIRE_MINUTES)
    access_token = create_access_token(
        data={"sub": user.username, "scope": " ".join(form_data.scopes)},
        expires_delta=access_token_expires,
    )
    return Token(access_token=access_token, token_type="bearer")


@app.get("/users/me/", response_model=User)
async def read_users_me(
    current_user: Annotated[User, Depends(get_current_active_user)],
):
    return current_user


@app.get("/users/me/items/")
async def read_own_items(
    current_user: Annotated[User, Security(get_current_active_user, scopes=["items"])],
):
    return [{"item_id": "Foo", "owner": current_user.username}]


@app.get("/status/")
async def read_system_status(current_user: Annotated[User, Depends(get_current_user)]):
    return {"status": "ok"}

from datetime import datetime, timedelta, timezone
from typing import List, Union

import jwt
from fastapi import Depends, FastAPI, HTTPException, Security, status
from fastapi.security import (
    OAuth2PasswordBearer,
    OAuth2PasswordRequestForm,
    SecurityScopes,
)
from jwt.exceptions import InvalidTokenError
from pwdlib import PasswordHash
from pydantic import BaseModel, ValidationError
from typing_extensions import Annotated

# to get a string like this run:
# openssl rand -hex 32
SECRET_KEY = "09d25e094faa6ca2556c818166b7a9563b93f7099f6f0f4caa6cf63b88e8d3e7"
ALGORITHM = "HS256"
ACCESS_TOKEN_EXPIRE_MINUTES = 30


fake_users_db = {
    "johndoe": {
        "username": "johndoe",
        "full_name": "John Doe",
        "email": "johndoe@example.com",
        "hashed_password": "$argon2id$v=19$m=65536,t=3,p=4$wagCPXjifgvUFBzq4hqe3w$CYaIb8sB+wtD+Vu/P4uod1+Qof8h+1g7bbDlBID48Rc",
        "disabled": False,
    },
    "alice": {
        "username": "alice",
        "full_name": "Alice Chains",
        "email": "alicechains@example.com",
        "hashed_password": "$argon2id$v=19$m=65536,t=3,p=4$g2/AV1zwopqUntPKJavBFw$BwpRGDCyUHLvHICnwijyX8ROGoiUPwNKZ7915MeYfCE",
        "disabled": True,
    },
}


class Token(BaseModel):
    access_token: str
    token_type: str


class TokenData(BaseModel):
    username: Union[str, None] = None
    scopes: List[str] = []


class User(BaseModel):
    username: str
    email: Union[str, None] = None
    full_name: Union[str, None] = None
    disabled: Union[bool, None] = None


class UserInDB(User):
    hashed_password: str


password_hash = PasswordHash.recommended()

oauth2_scheme = OAuth2PasswordBearer(
    tokenUrl="token",
    scopes={"me": "Read information about the current user.", "items": "Read items."},
)

app = FastAPI()


def verify_password(plain_password, hashed_password):
    return password_hash.verify(plain_password, hashed_password)


def get_password_hash(password):
    return password_hash.hash(password)


def get_user(db, username: str):
    if username in db:
        user_dict = db[username]
        return UserInDB(**user_dict)


def authenticate_user(fake_db, username: str, password: str):
    user = get_user(fake_db, username)
    if not user:
        return False
    if not verify_password(password, user.hashed_password):
        return False
    return user


def create_access_token(data: dict, expires_delta: Union[timedelta, None] = None):
    to_encode = data.copy()
    if expires_delta:
        expire = datetime.now(timezone.utc) + expires_delta
    else:
        expire = datetime.now(timezone.utc) + timedelta(minutes=15)
    to_encode.update({"exp": expire})
    encoded_jwt = jwt.encode(to_encode, SECRET_KEY, algorithm=ALGORITHM)
    return encoded_jwt


async def get_current_user(
    security_scopes: SecurityScopes, token: Annotated[str, Depends(oauth2_scheme)]
):
    if security_scopes.scopes:
        authenticate_value = f'Bearer scope="{security_scopes.scope_str}"'
    else:
        authenticate_value = "Bearer"
    credentials_exception = HTTPException(
        status_code=status.HTTP_401_UNAUTHORIZED,
        detail="Could not validate credentials",
        headers={"WWW-Authenticate": authenticate_value},
    )
    try:
        payload = jwt.decode(token, SECRET_KEY, algorithms=[ALGORITHM])
        username = payload.get("sub")
        if username is None:
            raise credentials_exception
        scope: str = payload.get("scope", "")
        token_scopes = scope.split(" ")
        token_data = TokenData(scopes=token_scopes, username=username)
    except (InvalidTokenError, ValidationError):
        raise credentials_exception
    user = get_user(fake_users_db, username=token_data.username)
    if user is None:
        raise credentials_exception
    for scope in security_scopes.scopes:
        if scope not in token_data.scopes:
            raise HTTPException(
                status_code=status.HTTP_401_UNAUTHORIZED,
                detail="Not enough permissions",
                headers={"WWW-Authenticate": authenticate_value},
            )
    return user


async def get_current_active_user(
    current_user: Annotated[User, Security(get_current_user, scopes=["me"])],
):
    if current_user.disabled:
        raise HTTPException(status_code=400, detail="Inactive user")
    return current_user


@app.post("/token")
async def login_for_access_token(
    form_data: Annotated[OAuth2PasswordRequestForm, Depends()],
) -> Token:
    user = authenticate_user(fake_users_db, form_data.username, form_data.password)
    if not user:
        raise HTTPException(status_code=400, detail="Incorrect username or password")
    access_token_expires = timedelta(minutes=ACCESS_TOKEN_EXPIRE_MINUTES)
    access_token = create_access_token(
        data={"sub": user.username, "scope": " ".join(form_data.scopes)},
        expires_delta=access_token_expires,
    )
    return Token(access_token=access_token, token_type="bearer")


@app.get("/users/me/", response_model=User)
async def read_users_me(
    current_user: Annotated[User, Depends(get_current_active_user)],
):
    return current_user


@app.get("/users/me/items/")
async def read_own_items(
    current_user: Annotated[User, Security(get_current_active_user, scopes=["items"])],
):
    return [{"item_id": "Foo", "owner": current_user.username}]


@app.get("/status/")
async def read_system_status(current_user: Annotated[User, Depends(get_current_user)]):
    return {"status": "ok"}

ヒント

可能であれば`Annotated`バージョンを使用することをお勧めします。

from datetime import datetime, timedelta, timezone

import jwt
from fastapi import Depends, FastAPI, HTTPException, Security, status
from fastapi.security import (
    OAuth2PasswordBearer,
    OAuth2PasswordRequestForm,
    SecurityScopes,
)
from jwt.exceptions import InvalidTokenError
from pwdlib import PasswordHash
from pydantic import BaseModel, ValidationError

# to get a string like this run:
# openssl rand -hex 32
SECRET_KEY = "09d25e094faa6ca2556c818166b7a9563b93f7099f6f0f4caa6cf63b88e8d3e7"
ALGORITHM = "HS256"
ACCESS_TOKEN_EXPIRE_MINUTES = 30


fake_users_db = {
    "johndoe": {
        "username": "johndoe",
        "full_name": "John Doe",
        "email": "johndoe@example.com",
        "hashed_password": "$argon2id$v=19$m=65536,t=3,p=4$wagCPXjifgvUFBzq4hqe3w$CYaIb8sB+wtD+Vu/P4uod1+Qof8h+1g7bbDlBID48Rc",
        "disabled": False,
    },
    "alice": {
        "username": "alice",
        "full_name": "Alice Chains",
        "email": "alicechains@example.com",
        "hashed_password": "$argon2id$v=19$m=65536,t=3,p=4$g2/AV1zwopqUntPKJavBFw$BwpRGDCyUHLvHICnwijyX8ROGoiUPwNKZ7915MeYfCE",
        "disabled": True,
    },
}


class Token(BaseModel):
    access_token: str
    token_type: str


class TokenData(BaseModel):
    username: str | None = None
    scopes: list[str] = []


class User(BaseModel):
    username: str
    email: str | None = None
    full_name: str | None = None
    disabled: bool | None = None


class UserInDB(User):
    hashed_password: str


password_hash = PasswordHash.recommended()

oauth2_scheme = OAuth2PasswordBearer(
    tokenUrl="token",
    scopes={"me": "Read information about the current user.", "items": "Read items."},
)

app = FastAPI()


def verify_password(plain_password, hashed_password):
    return password_hash.verify(plain_password, hashed_password)


def get_password_hash(password):
    return password_hash.hash(password)


def get_user(db, username: str):
    if username in db:
        user_dict = db[username]
        return UserInDB(**user_dict)


def authenticate_user(fake_db, username: str, password: str):
    user = get_user(fake_db, username)
    if not user:
        return False
    if not verify_password(password, user.hashed_password):
        return False
    return user


def create_access_token(data: dict, expires_delta: timedelta | None = None):
    to_encode = data.copy()
    if expires_delta:
        expire = datetime.now(timezone.utc) + expires_delta
    else:
        expire = datetime.now(timezone.utc) + timedelta(minutes=15)
    to_encode.update({"exp": expire})
    encoded_jwt = jwt.encode(to_encode, SECRET_KEY, algorithm=ALGORITHM)
    return encoded_jwt


async def get_current_user(
    security_scopes: SecurityScopes, token: str = Depends(oauth2_scheme)
):
    if security_scopes.scopes:
        authenticate_value = f'Bearer scope="{security_scopes.scope_str}"'
    else:
        authenticate_value = "Bearer"
    credentials_exception = HTTPException(
        status_code=status.HTTP_401_UNAUTHORIZED,
        detail="Could not validate credentials",
        headers={"WWW-Authenticate": authenticate_value},
    )
    try:
        payload = jwt.decode(token, SECRET_KEY, algorithms=[ALGORITHM])
        username: str = payload.get("sub")
        if username is None:
            raise credentials_exception
        scope: str = payload.get("scope", "")
        token_scopes = scope.split(" ")
        token_data = TokenData(scopes=token_scopes, username=username)
    except (InvalidTokenError, ValidationError):
        raise credentials_exception
    user = get_user(fake_users_db, username=token_data.username)
    if user is None:
        raise credentials_exception
    for scope in security_scopes.scopes:
        if scope not in token_data.scopes:
            raise HTTPException(
                status_code=status.HTTP_401_UNAUTHORIZED,
                detail="Not enough permissions",
                headers={"WWW-Authenticate": authenticate_value},
            )
    return user


async def get_current_active_user(
    current_user: User = Security(get_current_user, scopes=["me"]),
):
    if current_user.disabled:
        raise HTTPException(status_code=400, detail="Inactive user")
    return current_user


@app.post("/token")
async def login_for_access_token(
    form_data: OAuth2PasswordRequestForm = Depends(),
) -> Token:
    user = authenticate_user(fake_users_db, form_data.username, form_data.password)
    if not user:
        raise HTTPException(status_code=400, detail="Incorrect username or password")
    access_token_expires = timedelta(minutes=ACCESS_TOKEN_EXPIRE_MINUTES)
    access_token = create_access_token(
        data={"sub": user.username, "scope": " ".join(form_data.scopes)},
        expires_delta=access_token_expires,
    )
    return Token(access_token=access_token, token_type="bearer")


@app.get("/users/me/", response_model=User)
async def read_users_me(current_user: User = Depends(get_current_active_user)):
    return current_user


@app.get("/users/me/items/")
async def read_own_items(
    current_user: User = Security(get_current_active_user, scopes=["items"]),
):
    return [{"item_id": "Foo", "owner": current_user.username}]


@app.get("/status/")
async def read_system_status(current_user: User = Depends(get_current_user)):
    return {"status": "ok"}

ヒント

可能であれば`Annotated`バージョンを使用することをお勧めします。

from datetime import datetime, timedelta, timezone
from typing import Union

import jwt
from fastapi import Depends, FastAPI, HTTPException, Security, status
from fastapi.security import (
    OAuth2PasswordBearer,
    OAuth2PasswordRequestForm,
    SecurityScopes,
)
from jwt.exceptions import InvalidTokenError
from pwdlib import PasswordHash
from pydantic import BaseModel, ValidationError

# to get a string like this run:
# openssl rand -hex 32
SECRET_KEY = "09d25e094faa6ca2556c818166b7a9563b93f7099f6f0f4caa6cf63b88e8d3e7"
ALGORITHM = "HS256"
ACCESS_TOKEN_EXPIRE_MINUTES = 30


fake_users_db = {
    "johndoe": {
        "username": "johndoe",
        "full_name": "John Doe",
        "email": "johndoe@example.com",
        "hashed_password": "$argon2id$v=19$m=65536,t=3,p=4$wagCPXjifgvUFBzq4hqe3w$CYaIb8sB+wtD+Vu/P4uod1+Qof8h+1g7bbDlBID48Rc",
        "disabled": False,
    },
    "alice": {
        "username": "alice",
        "full_name": "Alice Chains",
        "email": "alicechains@example.com",
        "hashed_password": "$argon2id$v=19$m=65536,t=3,p=4$g2/AV1zwopqUntPKJavBFw$BwpRGDCyUHLvHICnwijyX8ROGoiUPwNKZ7915MeYfCE",
        "disabled": True,
    },
}


class Token(BaseModel):
    access_token: str
    token_type: str


class TokenData(BaseModel):
    username: Union[str, None] = None
    scopes: list[str] = []


class User(BaseModel):
    username: str
    email: Union[str, None] = None
    full_name: Union[str, None] = None
    disabled: Union[bool, None] = None


class UserInDB(User):
    hashed_password: str


password_hash = PasswordHash.recommended()

oauth2_scheme = OAuth2PasswordBearer(
    tokenUrl="token",
    scopes={"me": "Read information about the current user.", "items": "Read items."},
)

app = FastAPI()


def verify_password(plain_password, hashed_password):
    return password_hash.verify(plain_password, hashed_password)


def get_password_hash(password):
    return password_hash.hash(password)


def get_user(db, username: str):
    if username in db:
        user_dict = db[username]
        return UserInDB(**user_dict)


def authenticate_user(fake_db, username: str, password: str):
    user = get_user(fake_db, username)
    if not user:
        return False
    if not verify_password(password, user.hashed_password):
        return False
    return user


def create_access_token(data: dict, expires_delta: Union[timedelta, None] = None):
    to_encode = data.copy()
    if expires_delta:
        expire = datetime.now(timezone.utc) + expires_delta
    else:
        expire = datetime.now(timezone.utc) + timedelta(minutes=15)
    to_encode.update({"exp": expire})
    encoded_jwt = jwt.encode(to_encode, SECRET_KEY, algorithm=ALGORITHM)
    return encoded_jwt


async def get_current_user(
    security_scopes: SecurityScopes, token: str = Depends(oauth2_scheme)
):
    if security_scopes.scopes:
        authenticate_value = f'Bearer scope="{security_scopes.scope_str}"'
    else:
        authenticate_value = "Bearer"
    credentials_exception = HTTPException(
        status_code=status.HTTP_401_UNAUTHORIZED,
        detail="Could not validate credentials",
        headers={"WWW-Authenticate": authenticate_value},
    )
    try:
        payload = jwt.decode(token, SECRET_KEY, algorithms=[ALGORITHM])
        username: str = payload.get("sub")
        if username is None:
            raise credentials_exception
        scope: str = payload.get("scope", "")
        token_scopes = scope.split(" ")
        token_data = TokenData(scopes=token_scopes, username=username)
    except (InvalidTokenError, ValidationError):
        raise credentials_exception
    user = get_user(fake_users_db, username=token_data.username)
    if user is None:
        raise credentials_exception
    for scope in security_scopes.scopes:
        if scope not in token_data.scopes:
            raise HTTPException(
                status_code=status.HTTP_401_UNAUTHORIZED,
                detail="Not enough permissions",
                headers={"WWW-Authenticate": authenticate_value},
            )
    return user


async def get_current_active_user(
    current_user: User = Security(get_current_user, scopes=["me"]),
):
    if current_user.disabled:
        raise HTTPException(status_code=400, detail="Inactive user")
    return current_user


@app.post("/token")
async def login_for_access_token(
    form_data: OAuth2PasswordRequestForm = Depends(),
) -> Token:
    user = authenticate_user(fake_users_db, form_data.username, form_data.password)
    if not user:
        raise HTTPException(status_code=400, detail="Incorrect username or password")
    access_token_expires = timedelta(minutes=ACCESS_TOKEN_EXPIRE_MINUTES)
    access_token = create_access_token(
        data={"sub": user.username, "scope": " ".join(form_data.scopes)},
        expires_delta=access_token_expires,
    )
    return Token(access_token=access_token, token_type="bearer")


@app.get("/users/me/", response_model=User)
async def read_users_me(current_user: User = Depends(get_current_active_user)):
    return current_user


@app.get("/users/me/items/")
async def read_own_items(
    current_user: User = Security(get_current_active_user, scopes=["items"]),
):
    return [{"item_id": "Foo", "owner": current_user.username}]


@app.get("/status/")
async def read_system_status(current_user: User = Depends(get_current_user)):
    return {"status": "ok"}

ヒント

可能であれば`Annotated`バージョンを使用することをお勧めします。

from datetime import datetime, timedelta, timezone
from typing import List, Union

import jwt
from fastapi import Depends, FastAPI, HTTPException, Security, status
from fastapi.security import (
    OAuth2PasswordBearer,
    OAuth2PasswordRequestForm,
    SecurityScopes,
)
from jwt.exceptions import InvalidTokenError
from pwdlib import PasswordHash
from pydantic import BaseModel, ValidationError

# to get a string like this run:
# openssl rand -hex 32
SECRET_KEY = "09d25e094faa6ca2556c818166b7a9563b93f7099f6f0f4caa6cf63b88e8d3e7"
ALGORITHM = "HS256"
ACCESS_TOKEN_EXPIRE_MINUTES = 30


fake_users_db = {
    "johndoe": {
        "username": "johndoe",
        "full_name": "John Doe",
        "email": "johndoe@example.com",
        "hashed_password": "$argon2id$v=19$m=65536,t=3,p=4$wagCPXjifgvUFBzq4hqe3w$CYaIb8sB+wtD+Vu/P4uod1+Qof8h+1g7bbDlBID48Rc",
        "disabled": False,
    },
    "alice": {
        "username": "alice",
        "full_name": "Alice Chains",
        "email": "alicechains@example.com",
        "hashed_password": "$argon2id$v=19$m=65536,t=3,p=4$g2/AV1zwopqUntPKJavBFw$BwpRGDCyUHLvHICnwijyX8ROGoiUPwNKZ7915MeYfCE",
        "disabled": True,
    },
}


class Token(BaseModel):
    access_token: str
    token_type: str


class TokenData(BaseModel):
    username: Union[str, None] = None
    scopes: List[str] = []


class User(BaseModel):
    username: str
    email: Union[str, None] = None
    full_name: Union[str, None] = None
    disabled: Union[bool, None] = None


class UserInDB(User):
    hashed_password: str


password_hash = PasswordHash.recommended()

oauth2_scheme = OAuth2PasswordBearer(
    tokenUrl="token",
    scopes={"me": "Read information about the current user.", "items": "Read items."},
)

app = FastAPI()


def verify_password(plain_password, hashed_password):
    return password_hash.verify(plain_password, hashed_password)


def get_password_hash(password):
    return password_hash.hash(password)


def get_user(db, username: str):
    if username in db:
        user_dict = db[username]
        return UserInDB(**user_dict)


def authenticate_user(fake_db, username: str, password: str):
    user = get_user(fake_db, username)
    if not user:
        return False
    if not verify_password(password, user.hashed_password):
        return False
    return user


def create_access_token(data: dict, expires_delta: Union[timedelta, None] = None):
    to_encode = data.copy()
    if expires_delta:
        expire = datetime.now(timezone.utc) + expires_delta
    else:
        expire = datetime.now(timezone.utc) + timedelta(minutes=15)
    to_encode.update({"exp": expire})
    encoded_jwt = jwt.encode(to_encode, SECRET_KEY, algorithm=ALGORITHM)
    return encoded_jwt


async def get_current_user(
    security_scopes: SecurityScopes, token: str = Depends(oauth2_scheme)
):
    if security_scopes.scopes:
        authenticate_value = f'Bearer scope="{security_scopes.scope_str}"'
    else:
        authenticate_value = "Bearer"
    credentials_exception = HTTPException(
        status_code=status.HTTP_401_UNAUTHORIZED,
        detail="Could not validate credentials",
        headers={"WWW-Authenticate": authenticate_value},
    )
    try:
        payload = jwt.decode(token, SECRET_KEY, algorithms=[ALGORITHM])
        username: str = payload.get("sub")
        if username is None:
            raise credentials_exception
        scope: str = payload.get("scope", "")
        token_scopes = scope.split(" ")
        token_data = TokenData(scopes=token_scopes, username=username)
    except (InvalidTokenError, ValidationError):
        raise credentials_exception
    user = get_user(fake_users_db, username=token_data.username)
    if user is None:
        raise credentials_exception
    for scope in security_scopes.scopes:
        if scope not in token_data.scopes:
            raise HTTPException(
                status_code=status.HTTP_401_UNAUTHORIZED,
                detail="Not enough permissions",
                headers={"WWW-Authenticate": authenticate_value},
            )
    return user


async def get_current_active_user(
    current_user: User = Security(get_current_user, scopes=["me"]),
):
    if current_user.disabled:
        raise HTTPException(status_code=400, detail="Inactive user")
    return current_user


@app.post("/token")
async def login_for_access_token(
    form_data: OAuth2PasswordRequestForm = Depends(),
) -> Token:
    user = authenticate_user(fake_users_db, form_data.username, form_data.password)
    if not user:
        raise HTTPException(status_code=400, detail="Incorrect username or password")
    access_token_expires = timedelta(minutes=ACCESS_TOKEN_EXPIRE_MINUTES)
    access_token = create_access_token(
        data={"sub": user.username, "scope": " ".join(form_data.scopes)},
        expires_delta=access_token_expires,
    )
    return Token(access_token=access_token, token_type="bearer")


@app.get("/users/me/", response_model=User)
async def read_users_me(current_user: User = Depends(get_current_active_user)):
    return current_user


@app.get("/users/me/items/")
async def read_own_items(
    current_user: User = Security(get_current_active_user, scopes=["items"]),
):
    return [{"item_id": "Foo", "owner": current_user.username}]


@app.get("/status/")
async def read_system_status(current_user: User = Depends(get_current_user)):
    return {"status": "ok"}

それでは、これらの変更点を順を追って見ていきましょう。

OAuth2セキュリティスキーム

最初の変更点は、OAuth2セキュリティスキームをmeとitemsという2つの利用可能なスコープで宣言していることです。

scopesパラメータは、各スコープをキーとして、その説明を値として持つdictを受け取ります

Python 3.10+

from datetime import datetime, timedelta, timezone
from typing import Annotated

import jwt
from fastapi import Depends, FastAPI, HTTPException, Security, status
from fastapi.security import (
    OAuth2PasswordBearer,
    OAuth2PasswordRequestForm,
    SecurityScopes,
)
from jwt.exceptions import InvalidTokenError
from pwdlib import PasswordHash
from pydantic import BaseModel, ValidationError

# to get a string like this run:
# openssl rand -hex 32
SECRET_KEY = "09d25e094faa6ca2556c818166b7a9563b93f7099f6f0f4caa6cf63b88e8d3e7"
ALGORITHM = "HS256"
ACCESS_TOKEN_EXPIRE_MINUTES = 30


fake_users_db = {
    "johndoe": {
        "username": "johndoe",
        "full_name": "John Doe",
        "email": "johndoe@example.com",
        "hashed_password": "$argon2id$v=19$m=65536,t=3,p=4$wagCPXjifgvUFBzq4hqe3w$CYaIb8sB+wtD+Vu/P4uod1+Qof8h+1g7bbDlBID48Rc",
        "disabled": False,
    },
    "alice": {
        "username": "alice",
        "full_name": "Alice Chains",
        "email": "alicechains@example.com",
        "hashed_password": "$argon2id$v=19$m=65536,t=3,p=4$g2/AV1zwopqUntPKJavBFw$BwpRGDCyUHLvHICnwijyX8ROGoiUPwNKZ7915MeYfCE",
        "disabled": True,
    },
}


class Token(BaseModel):
    access_token: str
    token_type: str


class TokenData(BaseModel):
    username: str | None = None
    scopes: list[str] = []


class User(BaseModel):
    username: str
    email: str | None = None
    full_name: str | None = None
    disabled: bool | None = None


class UserInDB(User):
    hashed_password: str


password_hash = PasswordHash.recommended()

oauth2_scheme = OAuth2PasswordBearer(
    tokenUrl="token",
    scopes={"me": "Read information about the current user.", "items": "Read items."},
)

app = FastAPI()


def verify_password(plain_password, hashed_password):
    return password_hash.verify(plain_password, hashed_password)


def get_password_hash(password):
    return password_hash.hash(password)


def get_user(db, username: str):
    if username in db:
        user_dict = db[username]
        return UserInDB(**user_dict)


def authenticate_user(fake_db, username: str, password: str):
    user = get_user(fake_db, username)
    if not user:
        return False
    if not verify_password(password, user.hashed_password):
        return False
    return user


def create_access_token(data: dict, expires_delta: timedelta | None = None):
    to_encode = data.copy()
    if expires_delta:
        expire = datetime.now(timezone.utc) + expires_delta
    else:
        expire = datetime.now(timezone.utc) + timedelta(minutes=15)
    to_encode.update({"exp": expire})
    encoded_jwt = jwt.encode(to_encode, SECRET_KEY, algorithm=ALGORITHM)
    return encoded_jwt


async def get_current_user(
    security_scopes: SecurityScopes, token: Annotated[str, Depends(oauth2_scheme)]
):
    if security_scopes.scopes:
        authenticate_value = f'Bearer scope="{security_scopes.scope_str}"'
    else:
        authenticate_value = "Bearer"
    credentials_exception = HTTPException(
        status_code=status.HTTP_401_UNAUTHORIZED,
        detail="Could not validate credentials",
        headers={"WWW-Authenticate": authenticate_value},
    )
    try:
        payload = jwt.decode(token, SECRET_KEY, algorithms=[ALGORITHM])
        username = payload.get("sub")
        if username is None:
            raise credentials_exception
        scope: str = payload.get("scope", "")
        token_scopes = scope.split(" ")
        token_data = TokenData(scopes=token_scopes, username=username)
    except (InvalidTokenError, ValidationError):
        raise credentials_exception
    user = get_user(fake_users_db, username=token_data.username)
    if user is None:
        raise credentials_exception
    for scope in security_scopes.scopes:
        if scope not in token_data.scopes:
            raise HTTPException(
                status_code=status.HTTP_401_UNAUTHORIZED,
                detail="Not enough permissions",
                headers={"WWW-Authenticate": authenticate_value},
            )
    return user


async def get_current_active_user(
    current_user: Annotated[User, Security(get_current_user, scopes=["me"])],
):
    if current_user.disabled:
        raise HTTPException(status_code=400, detail="Inactive user")
    return current_user


@app.post("/token")
async def login_for_access_token(
    form_data: Annotated[OAuth2PasswordRequestForm, Depends()],
) -> Token:
    user = authenticate_user(fake_users_db, form_data.username, form_data.password)
    if not user:
        raise HTTPException(status_code=400, detail="Incorrect username or password")
    access_token_expires = timedelta(minutes=ACCESS_TOKEN_EXPIRE_MINUTES)
    access_token = create_access_token(
        data={"sub": user.username, "scope": " ".join(form_data.scopes)},
        expires_delta=access_token_expires,
    )
    return Token(access_token=access_token, token_type="bearer")


@app.get("/users/me/", response_model=User)
async def read_users_me(
    current_user: Annotated[User, Depends(get_current_active_user)],
):
    return current_user


@app.get("/users/me/items/")
async def read_own_items(
    current_user: Annotated[User, Security(get_current_active_user, scopes=["items"])],
):
    return [{"item_id": "Foo", "owner": current_user.username}]


@app.get("/status/")
async def read_system_status(current_user: Annotated[User, Depends(get_current_user)]):
    return {"status": "ok"}

🤓 その他のバージョンとバリアント

Python 3.9+Python 3.8+Python 3.10+ - non-AnnotatedPython 3.9+ - 非注釈付きPython 3.8+ - non-Annotated

from datetime import datetime, timedelta, timezone
from typing import Annotated, Union

import jwt
from fastapi import Depends, FastAPI, HTTPException, Security, status
from fastapi.security import (
    OAuth2PasswordBearer,
    OAuth2PasswordRequestForm,
    SecurityScopes,
)
from jwt.exceptions import InvalidTokenError
from pwdlib import PasswordHash
from pydantic import BaseModel, ValidationError

# to get a string like this run:
# openssl rand -hex 32
SECRET_KEY = "09d25e094faa6ca2556c818166b7a9563b93f7099f6f0f4caa6cf63b88e8d3e7"
ALGORITHM = "HS256"
ACCESS_TOKEN_EXPIRE_MINUTES = 30


fake_users_db = {
    "johndoe": {
        "username": "johndoe",
        "full_name": "John Doe",
        "email": "johndoe@example.com",
        "hashed_password": "$argon2id$v=19$m=65536,t=3,p=4$wagCPXjifgvUFBzq4hqe3w$CYaIb8sB+wtD+Vu/P4uod1+Qof8h+1g7bbDlBID48Rc",
        "disabled": False,
    },
    "alice": {
        "username": "alice",
        "full_name": "Alice Chains",
        "email": "alicechains@example.com",
        "hashed_password": "$argon2id$v=19$m=65536,t=3,p=4$g2/AV1zwopqUntPKJavBFw$BwpRGDCyUHLvHICnwijyX8ROGoiUPwNKZ7915MeYfCE",
        "disabled": True,
    },
}


class Token(BaseModel):
    access_token: str
    token_type: str


class TokenData(BaseModel):
    username: Union[str, None] = None
    scopes: list[str] = []


class User(BaseModel):
    username: str
    email: Union[str, None] = None
    full_name: Union[str, None] = None
    disabled: Union[bool, None] = None


class UserInDB(User):
    hashed_password: str


password_hash = PasswordHash.recommended()

oauth2_scheme = OAuth2PasswordBearer(
    tokenUrl="token",
    scopes={"me": "Read information about the current user.", "items": "Read items."},
)

app = FastAPI()


def verify_password(plain_password, hashed_password):
    return password_hash.verify(plain_password, hashed_password)


def get_password_hash(password):
    return password_hash.hash(password)


def get_user(db, username: str):
    if username in db:
        user_dict = db[username]
        return UserInDB(**user_dict)


def authenticate_user(fake_db, username: str, password: str):
    user = get_user(fake_db, username)
    if not user:
        return False
    if not verify_password(password, user.hashed_password):
        return False
    return user


def create_access_token(data: dict, expires_delta: Union[timedelta, None] = None):
    to_encode = data.copy()
    if expires_delta:
        expire = datetime.now(timezone.utc) + expires_delta
    else:
        expire = datetime.now(timezone.utc) + timedelta(minutes=15)
    to_encode.update({"exp": expire})
    encoded_jwt = jwt.encode(to_encode, SECRET_KEY, algorithm=ALGORITHM)
    return encoded_jwt


async def get_current_user(
    security_scopes: SecurityScopes, token: Annotated[str, Depends(oauth2_scheme)]
):
    if security_scopes.scopes:
        authenticate_value = f'Bearer scope="{security_scopes.scope_str}"'
    else:
        authenticate_value = "Bearer"
    credentials_exception = HTTPException(
        status_code=status.HTTP_401_UNAUTHORIZED,
        detail="Could not validate credentials",
        headers={"WWW-Authenticate": authenticate_value},
    )
    try:
        payload = jwt.decode(token, SECRET_KEY, algorithms=[ALGORITHM])
        username = payload.get("sub")
        if username is None:
            raise credentials_exception
        scope: str = payload.get("scope", "")
        token_scopes = scope.split(" ")
        token_data = TokenData(scopes=token_scopes, username=username)
    except (InvalidTokenError, ValidationError):
        raise credentials_exception
    user = get_user(fake_users_db, username=token_data.username)
    if user is None:
        raise credentials_exception
    for scope in security_scopes.scopes:
        if scope not in token_data.scopes:
            raise HTTPException(
                status_code=status.HTTP_401_UNAUTHORIZED,
                detail="Not enough permissions",
                headers={"WWW-Authenticate": authenticate_value},
            )
    return user


async def get_current_active_user(
    current_user: Annotated[User, Security(get_current_user, scopes=["me"])],
):
    if current_user.disabled:
        raise HTTPException(status_code=400, detail="Inactive user")
    return current_user


@app.post("/token")
async def login_for_access_token(
    form_data: Annotated[OAuth2PasswordRequestForm, Depends()],
) -> Token:
    user = authenticate_user(fake_users_db, form_data.username, form_data.password)
    if not user:
        raise HTTPException(status_code=400, detail="Incorrect username or password")
    access_token_expires = timedelta(minutes=ACCESS_TOKEN_EXPIRE_MINUTES)
    access_token = create_access_token(
        data={"sub": user.username, "scope": " ".join(form_data.scopes)},
        expires_delta=access_token_expires,
    )
    return Token(access_token=access_token, token_type="bearer")


@app.get("/users/me/", response_model=User)
async def read_users_me(
    current_user: Annotated[User, Depends(get_current_active_user)],
):
    return current_user


@app.get("/users/me/items/")
async def read_own_items(
    current_user: Annotated[User, Security(get_current_active_user, scopes=["items"])],
):
    return [{"item_id": "Foo", "owner": current_user.username}]


@app.get("/status/")
async def read_system_status(current_user: Annotated[User, Depends(get_current_user)]):
    return {"status": "ok"}

from datetime import datetime, timedelta, timezone
from typing import List, Union

import jwt
from fastapi import Depends, FastAPI, HTTPException, Security, status
from fastapi.security import (
    OAuth2PasswordBearer,
    OAuth2PasswordRequestForm,
    SecurityScopes,
)
from jwt.exceptions import InvalidTokenError
from pwdlib import PasswordHash
from pydantic import BaseModel, ValidationError
from typing_extensions import Annotated

# to get a string like this run:
# openssl rand -hex 32
SECRET_KEY = "09d25e094faa6ca2556c818166b7a9563b93f7099f6f0f4caa6cf63b88e8d3e7"
ALGORITHM = "HS256"
ACCESS_TOKEN_EXPIRE_MINUTES = 30


fake_users_db = {
    "johndoe": {
        "username": "johndoe",
        "full_name": "John Doe",
        "email": "johndoe@example.com",
        "hashed_password": "$argon2id$v=19$m=65536,t=3,p=4$wagCPXjifgvUFBzq4hqe3w$CYaIb8sB+wtD+Vu/P4uod1+Qof8h+1g7bbDlBID48Rc",
        "disabled": False,
    },
    "alice": {
        "username": "alice",
        "full_name": "Alice Chains",
        "email": "alicechains@example.com",
        "hashed_password": "$argon2id$v=19$m=65536,t=3,p=4$g2/AV1zwopqUntPKJavBFw$BwpRGDCyUHLvHICnwijyX8ROGoiUPwNKZ7915MeYfCE",
        "disabled": True,
    },
}


class Token(BaseModel):
    access_token: str
    token_type: str


class TokenData(BaseModel):
    username: Union[str, None] = None
    scopes: List[str] = []


class User(BaseModel):
    username: str
    email: Union[str, None] = None
    full_name: Union[str, None] = None
    disabled: Union[bool, None] = None


class UserInDB(User):
    hashed_password: str


password_hash = PasswordHash.recommended()

oauth2_scheme = OAuth2PasswordBearer(
    tokenUrl="token",
    scopes={"me": "Read information about the current user.", "items": "Read items."},
)

app = FastAPI()


def verify_password(plain_password, hashed_password):
    return password_hash.verify(plain_password, hashed_password)


def get_password_hash(password):
    return password_hash.hash(password)


def get_user(db, username: str):
    if username in db:
        user_dict = db[username]
        return UserInDB(**user_dict)


def authenticate_user(fake_db, username: str, password: str):
    user = get_user(fake_db, username)
    if not user:
        return False
    if not verify_password(password, user.hashed_password):
        return False
    return user


def create_access_token(data: dict, expires_delta: Union[timedelta, None] = None):
    to_encode = data.copy()
    if expires_delta:
        expire = datetime.now(timezone.utc) + expires_delta
    else:
        expire = datetime.now(timezone.utc) + timedelta(minutes=15)
    to_encode.update({"exp": expire})
    encoded_jwt = jwt.encode(to_encode, SECRET_KEY, algorithm=ALGORITHM)
    return encoded_jwt


async def get_current_user(
    security_scopes: SecurityScopes, token: Annotated[str, Depends(oauth2_scheme)]
):
    if security_scopes.scopes:
        authenticate_value = f'Bearer scope="{security_scopes.scope_str}"'
    else:
        authenticate_value = "Bearer"
    credentials_exception = HTTPException(
        status_code=status.HTTP_401_UNAUTHORIZED,
        detail="Could not validate credentials",
        headers={"WWW-Authenticate": authenticate_value},
    )
    try:
        payload = jwt.decode(token, SECRET_KEY, algorithms=[ALGORITHM])
        username = payload.get("sub")
        if username is None:
            raise credentials_exception
        scope: str = payload.get("scope", "")
        token_scopes = scope.split(" ")
        token_data = TokenData(scopes=token_scopes, username=username)
    except (InvalidTokenError, ValidationError):
        raise credentials_exception
    user = get_user(fake_users_db, username=token_data.username)
    if user is None:
        raise credentials_exception
    for scope in security_scopes.scopes:
        if scope not in token_data.scopes:
            raise HTTPException(
                status_code=status.HTTP_401_UNAUTHORIZED,
                detail="Not enough permissions",
                headers={"WWW-Authenticate": authenticate_value},
            )
    return user


async def get_current_active_user(
    current_user: Annotated[User, Security(get_current_user, scopes=["me"])],
):
    if current_user.disabled:
        raise HTTPException(status_code=400, detail="Inactive user")
    return current_user


@app.post("/token")
async def login_for_access_token(
    form_data: Annotated[OAuth2PasswordRequestForm, Depends()],
) -> Token:
    user = authenticate_user(fake_users_db, form_data.username, form_data.password)
    if not user:
        raise HTTPException(status_code=400, detail="Incorrect username or password")
    access_token_expires = timedelta(minutes=ACCESS_TOKEN_EXPIRE_MINUTES)
    access_token = create_access_token(
        data={"sub": user.username, "scope": " ".join(form_data.scopes)},
        expires_delta=access_token_expires,
    )
    return Token(access_token=access_token, token_type="bearer")


@app.get("/users/me/", response_model=User)
async def read_users_me(
    current_user: Annotated[User, Depends(get_current_active_user)],
):
    return current_user


@app.get("/users/me/items/")
async def read_own_items(
    current_user: Annotated[User, Security(get_current_active_user, scopes=["items"])],
):
    return [{"item_id": "Foo", "owner": current_user.username}]


@app.get("/status/")
async def read_system_status(current_user: Annotated[User, Depends(get_current_user)]):
    return {"status": "ok"}

ヒント

可能であれば`Annotated`バージョンを使用することをお勧めします。

from datetime import datetime, timedelta, timezone

import jwt
from fastapi import Depends, FastAPI, HTTPException, Security, status
from fastapi.security import (
    OAuth2PasswordBearer,
    OAuth2PasswordRequestForm,
    SecurityScopes,
)
from jwt.exceptions import InvalidTokenError
from pwdlib import PasswordHash
from pydantic import BaseModel, ValidationError

# to get a string like this run:
# openssl rand -hex 32
SECRET_KEY = "09d25e094faa6ca2556c818166b7a9563b93f7099f6f0f4caa6cf63b88e8d3e7"
ALGORITHM = "HS256"
ACCESS_TOKEN_EXPIRE_MINUTES = 30


fake_users_db = {
    "johndoe": {
        "username": "johndoe",
        "full_name": "John Doe",
        "email": "johndoe@example.com",
        "hashed_password": "$argon2id$v=19$m=65536,t=3,p=4$wagCPXjifgvUFBzq4hqe3w$CYaIb8sB+wtD+Vu/P4uod1+Qof8h+1g7bbDlBID48Rc",
        "disabled": False,
    },
    "alice": {
        "username": "alice",
        "full_name": "Alice Chains",
        "email": "alicechains@example.com",
        "hashed_password": "$argon2id$v=19$m=65536,t=3,p=4$g2/AV1zwopqUntPKJavBFw$BwpRGDCyUHLvHICnwijyX8ROGoiUPwNKZ7915MeYfCE",
        "disabled": True,
    },
}


class Token(BaseModel):
    access_token: str
    token_type: str


class TokenData(BaseModel):
    username: str | None = None
    scopes: list[str] = []


class User(BaseModel):
    username: str
    email: str | None = None
    full_name: str | None = None
    disabled: bool | None = None


class UserInDB(User):
    hashed_password: str


password_hash = PasswordHash.recommended()

oauth2_scheme = OAuth2PasswordBearer(
    tokenUrl="token",
    scopes={"me": "Read information about the current user.", "items": "Read items."},
)

app = FastAPI()


def verify_password(plain_password, hashed_password):
    return password_hash.verify(plain_password, hashed_password)


def get_password_hash(password):
    return password_hash.hash(password)


def get_user(db, username: str):
    if username in db:
        user_dict = db[username]
        return UserInDB(**user_dict)


def authenticate_user(fake_db, username: str, password: str):
    user = get_user(fake_db, username)
    if not user:
        return False
    if not verify_password(password, user.hashed_password):
        return False
    return user


def create_access_token(data: dict, expires_delta: timedelta | None = None):
    to_encode = data.copy()
    if expires_delta:
        expire = datetime.now(timezone.utc) + expires_delta
    else:
        expire = datetime.now(timezone.utc) + timedelta(minutes=15)
    to_encode.update({"exp": expire})
    encoded_jwt = jwt.encode(to_encode, SECRET_KEY, algorithm=ALGORITHM)
    return encoded_jwt


async def get_current_user(
    security_scopes: SecurityScopes, token: str = Depends(oauth2_scheme)
):
    if security_scopes.scopes:
        authenticate_value = f'Bearer scope="{security_scopes.scope_str}"'
    else:
        authenticate_value = "Bearer"
    credentials_exception = HTTPException(
        status_code=status.HTTP_401_UNAUTHORIZED,
        detail="Could not validate credentials",
        headers={"WWW-Authenticate": authenticate_value},
    )
    try:
        payload = jwt.decode(token, SECRET_KEY, algorithms=[ALGORITHM])
        username: str = payload.get("sub")
        if username is None:
            raise credentials_exception
        scope: str = payload.get("scope", "")
        token_scopes = scope.split(" ")
        token_data = TokenData(scopes=token_scopes, username=username)
    except (InvalidTokenError, ValidationError):
        raise credentials_exception
    user = get_user(fake_users_db, username=token_data.username)
    if user is None:
        raise credentials_exception
    for scope in security_scopes.scopes:
        if scope not in token_data.scopes:
            raise HTTPException(
                status_code=status.HTTP_401_UNAUTHORIZED,
                detail="Not enough permissions",
                headers={"WWW-Authenticate": authenticate_value},
            )
    return user


async def get_current_active_user(
    current_user: User = Security(get_current_user, scopes=["me"]),
):
    if current_user.disabled:
        raise HTTPException(status_code=400, detail="Inactive user")
    return current_user


@app.post("/token")
async def login_for_access_token(
    form_data: OAuth2PasswordRequestForm = Depends(),
) -> Token:
    user = authenticate_user(fake_users_db, form_data.username, form_data.password)
    if not user:
        raise HTTPException(status_code=400, detail="Incorrect username or password")
    access_token_expires = timedelta(minutes=ACCESS_TOKEN_EXPIRE_MINUTES)
    access_token = create_access_token(
        data={"sub": user.username, "scope": " ".join(form_data.scopes)},
        expires_delta=access_token_expires,
    )
    return Token(access_token=access_token, token_type="bearer")


@app.get("/users/me/", response_model=User)
async def read_users_me(current_user: User = Depends(get_current_active_user)):
    return current_user


@app.get("/users/me/items/")
async def read_own_items(
    current_user: User = Security(get_current_active_user, scopes=["items"]),
):
    return [{"item_id": "Foo", "owner": current_user.username}]


@app.get("/status/")
async def read_system_status(current_user: User = Depends(get_current_user)):
    return {"status": "ok"}

ヒント

可能であれば`Annotated`バージョンを使用することをお勧めします。

from datetime import datetime, timedelta, timezone
from typing import Union

import jwt
from fastapi import Depends, FastAPI, HTTPException, Security, status
from fastapi.security import (
    OAuth2PasswordBearer,
    OAuth2PasswordRequestForm,
    SecurityScopes,
)
from jwt.exceptions import InvalidTokenError
from pwdlib import PasswordHash
from pydantic import BaseModel, ValidationError

# to get a string like this run:
# openssl rand -hex 32
SECRET_KEY = "09d25e094faa6ca2556c818166b7a9563b93f7099f6f0f4caa6cf63b88e8d3e7"
ALGORITHM = "HS256"
ACCESS_TOKEN_EXPIRE_MINUTES = 30


fake_users_db = {
    "johndoe": {
        "username": "johndoe",
        "full_name": "John Doe",
        "email": "johndoe@example.com",
        "hashed_password": "$argon2id$v=19$m=65536,t=3,p=4$wagCPXjifgvUFBzq4hqe3w$CYaIb8sB+wtD+Vu/P4uod1+Qof8h+1g7bbDlBID48Rc",
        "disabled": False,
    },
    "alice": {
        "username": "alice",
        "full_name": "Alice Chains",
        "email": "alicechains@example.com",
        "hashed_password": "$argon2id$v=19$m=65536,t=3,p=4$g2/AV1zwopqUntPKJavBFw$BwpRGDCyUHLvHICnwijyX8ROGoiUPwNKZ7915MeYfCE",
        "disabled": True,
    },
}


class Token(BaseModel):
    access_token: str
    token_type: str


class TokenData(BaseModel):
    username: Union[str, None] = None
    scopes: list[str] = []


class User(BaseModel):
    username: str
    email: Union[str, None] = None
    full_name: Union[str, None] = None
    disabled: Union[bool, None] = None


class UserInDB(User):
    hashed_password: str


password_hash = PasswordHash.recommended()

oauth2_scheme = OAuth2PasswordBearer(
    tokenUrl="token",
    scopes={"me": "Read information about the current user.", "items": "Read items."},
)

app = FastAPI()


def verify_password(plain_password, hashed_password):
    return password_hash.verify(plain_password, hashed_password)


def get_password_hash(password):
    return password_hash.hash(password)


def get_user(db, username: str):
    if username in db:
        user_dict = db[username]
        return UserInDB(**user_dict)


def authenticate_user(fake_db, username: str, password: str):
    user = get_user(fake_db, username)
    if not user:
        return False
    if not verify_password(password, user.hashed_password):
        return False
    return user


def create_access_token(data: dict, expires_delta: Union[timedelta, None] = None):
    to_encode = data.copy()
    if expires_delta:
        expire = datetime.now(timezone.utc) + expires_delta
    else:
        expire = datetime.now(timezone.utc) + timedelta(minutes=15)
    to_encode.update({"exp": expire})
    encoded_jwt = jwt.encode(to_encode, SECRET_KEY, algorithm=ALGORITHM)
    return encoded_jwt


async def get_current_user(
    security_scopes: SecurityScopes, token: str = Depends(oauth2_scheme)
):
    if security_scopes.scopes:
        authenticate_value = f'Bearer scope="{security_scopes.scope_str}"'
    else:
        authenticate_value = "Bearer"
    credentials_exception = HTTPException(
        status_code=status.HTTP_401_UNAUTHORIZED,
        detail="Could not validate credentials",
        headers={"WWW-Authenticate": authenticate_value},
    )
    try:
        payload = jwt.decode(token, SECRET_KEY, algorithms=[ALGORITHM])
        username: str = payload.get("sub")
        if username is None:
            raise credentials_exception
        scope: str = payload.get("scope", "")
        token_scopes = scope.split(" ")
        token_data = TokenData(scopes=token_scopes, username=username)
    except (InvalidTokenError, ValidationError):
        raise credentials_exception
    user = get_user(fake_users_db, username=token_data.username)
    if user is None:
        raise credentials_exception
    for scope in security_scopes.scopes:
        if scope not in token_data.scopes:
            raise HTTPException(
                status_code=status.HTTP_401_UNAUTHORIZED,
                detail="Not enough permissions",
                headers={"WWW-Authenticate": authenticate_value},
            )
    return user


async def get_current_active_user(
    current_user: User = Security(get_current_user, scopes=["me"]),
):
    if current_user.disabled:
        raise HTTPException(status_code=400, detail="Inactive user")
    return current_user


@app.post("/token")
async def login_for_access_token(
    form_data: OAuth2PasswordRequestForm = Depends(),
) -> Token:
    user = authenticate_user(fake_users_db, form_data.username, form_data.password)
    if not user:
        raise HTTPException(status_code=400, detail="Incorrect username or password")
    access_token_expires = timedelta(minutes=ACCESS_TOKEN_EXPIRE_MINUTES)
    access_token = create_access_token(
        data={"sub": user.username, "scope": " ".join(form_data.scopes)},
        expires_delta=access_token_expires,
    )
    return Token(access_token=access_token, token_type="bearer")


@app.get("/users/me/", response_model=User)
async def read_users_me(current_user: User = Depends(get_current_active_user)):
    return current_user


@app.get("/users/me/items/")
async def read_own_items(
    current_user: User = Security(get_current_active_user, scopes=["items"]),
):
    return [{"item_id": "Foo", "owner": current_user.username}]


@app.get("/status/")
async def read_system_status(current_user: User = Depends(get_current_user)):
    return {"status": "ok"}

ヒント

可能であれば`Annotated`バージョンを使用することをお勧めします。

from datetime import datetime, timedelta, timezone
from typing import List, Union

import jwt
from fastapi import Depends, FastAPI, HTTPException, Security, status
from fastapi.security import (
    OAuth2PasswordBearer,
    OAuth2PasswordRequestForm,
    SecurityScopes,
)
from jwt.exceptions import InvalidTokenError
from pwdlib import PasswordHash
from pydantic import BaseModel, ValidationError

# to get a string like this run:
# openssl rand -hex 32
SECRET_KEY = "09d25e094faa6ca2556c818166b7a9563b93f7099f6f0f4caa6cf63b88e8d3e7"
ALGORITHM = "HS256"
ACCESS_TOKEN_EXPIRE_MINUTES = 30


fake_users_db = {
    "johndoe": {
        "username": "johndoe",
        "full_name": "John Doe",
        "email": "johndoe@example.com",
        "hashed_password": "$argon2id$v=19$m=65536,t=3,p=4$wagCPXjifgvUFBzq4hqe3w$CYaIb8sB+wtD+Vu/P4uod1+Qof8h+1g7bbDlBID48Rc",
        "disabled": False,
    },
    "alice": {
        "username": "alice",
        "full_name": "Alice Chains",
        "email": "alicechains@example.com",
        "hashed_password": "$argon2id$v=19$m=65536,t=3,p=4$g2/AV1zwopqUntPKJavBFw$BwpRGDCyUHLvHICnwijyX8ROGoiUPwNKZ7915MeYfCE",
        "disabled": True,
    },
}


class Token(BaseModel):
    access_token: str
    token_type: str


class TokenData(BaseModel):
    username: Union[str, None] = None
    scopes: List[str] = []


class User(BaseModel):
    username: str
    email: Union[str, None] = None
    full_name: Union[str, None] = None
    disabled: Union[bool, None] = None


class UserInDB(User):
    hashed_password: str


password_hash = PasswordHash.recommended()

oauth2_scheme = OAuth2PasswordBearer(
    tokenUrl="token",
    scopes={"me": "Read information about the current user.", "items": "Read items."},
)

app = FastAPI()


def verify_password(plain_password, hashed_password):
    return password_hash.verify(plain_password, hashed_password)


def get_password_hash(password):
    return password_hash.hash(password)


def get_user(db, username: str):
    if username in db:
        user_dict = db[username]
        return UserInDB(**user_dict)


def authenticate_user(fake_db, username: str, password: str):
    user = get_user(fake_db, username)
    if not user:
        return False
    if not verify_password(password, user.hashed_password):
        return False
    return user


def create_access_token(data: dict, expires_delta: Union[timedelta, None] = None):
    to_encode = data.copy()
    if expires_delta:
        expire = datetime.now(timezone.utc) + expires_delta
    else:
        expire = datetime.now(timezone.utc) + timedelta(minutes=15)
    to_encode.update({"exp": expire})
    encoded_jwt = jwt.encode(to_encode, SECRET_KEY, algorithm=ALGORITHM)
    return encoded_jwt


async def get_current_user(
    security_scopes: SecurityScopes, token: str = Depends(oauth2_scheme)
):
    if security_scopes.scopes:
        authenticate_value = f'Bearer scope="{security_scopes.scope_str}"'
    else:
        authenticate_value = "Bearer"
    credentials_exception = HTTPException(
        status_code=status.HTTP_401_UNAUTHORIZED,
        detail="Could not validate credentials",
        headers={"WWW-Authenticate": authenticate_value},
    )
    try:
        payload = jwt.decode(token, SECRET_KEY, algorithms=[ALGORITHM])
        username: str = payload.get("sub")
        if username is None:
            raise credentials_exception
        scope: str = payload.get("scope", "")
        token_scopes = scope.split(" ")
        token_data = TokenData(scopes=token_scopes, username=username)
    except (InvalidTokenError, ValidationError):
        raise credentials_exception
    user = get_user(fake_users_db, username=token_data.username)
    if user is None:
        raise credentials_exception
    for scope in security_scopes.scopes:
        if scope not in token_data.scopes:
            raise HTTPException(
                status_code=status.HTTP_401_UNAUTHORIZED,
                detail="Not enough permissions",
                headers={"WWW-Authenticate": authenticate_value},
            )
    return user


async def get_current_active_user(
    current_user: User = Security(get_current_user, scopes=["me"]),
):
    if current_user.disabled:
        raise HTTPException(status_code=400, detail="Inactive user")
    return current_user


@app.post("/token")
async def login_for_access_token(
    form_data: OAuth2PasswordRequestForm = Depends(),
) -> Token:
    user = authenticate_user(fake_users_db, form_data.username, form_data.password)
    if not user:
        raise HTTPException(status_code=400, detail="Incorrect username or password")
    access_token_expires = timedelta(minutes=ACCESS_TOKEN_EXPIRE_MINUTES)
    access_token = create_access_token(
        data={"sub": user.username, "scope": " ".join(form_data.scopes)},
        expires_delta=access_token_expires,
    )
    return Token(access_token=access_token, token_type="bearer")


@app.get("/users/me/", response_model=User)
async def read_users_me(current_user: User = Depends(get_current_active_user)):
    return current_user


@app.get("/users/me/items/")
async def read_own_items(
    current_user: User = Security(get_current_active_user, scopes=["items"]),
):
    return [{"item_id": "Foo", "owner": current_user.username}]


@app.get("/status/")
async def read_system_status(current_user: User = Depends(get_current_user)):
    return {"status": "ok"}

これらのスコープを宣言したため、ログイン/承認時にAPIドキュメントに表示されます。

そして、アクセスを許可したいスコープを選択できるようになります: meとitems。

これは、Facebook、Google、GitHubなどでログインする際にパーミッションを付与するのと同じメカニズムです。

スコープ付きJWTトークン

次に、要求されたスコープを返すようにトークンパス操作を変更します。

引き続き同じOAuth2PasswordRequestFormを使用しています。これには、要求で受け取った各スコープを含むstrのlistであるscopesプロパティが含まれています。

そして、スコープをJWTトークンの一部として返します。

危険

ここでは、簡潔にするために、受け取ったスコープを直接トークンに追加しています。

しかし、アプリケーションでは、セキュリティのために、ユーザーが実際に持つことができるスコープ、または事前に定義したスコープのみを追加するようにしてください。

Python 3.10+

from datetime import datetime, timedelta, timezone
from typing import Annotated

import jwt
from fastapi import Depends, FastAPI, HTTPException, Security, status
from fastapi.security import (
    OAuth2PasswordBearer,
    OAuth2PasswordRequestForm,
    SecurityScopes,
)
from jwt.exceptions import InvalidTokenError
from pwdlib import PasswordHash
from pydantic import BaseModel, ValidationError

# to get a string like this run:
# openssl rand -hex 32
SECRET_KEY = "09d25e094faa6ca2556c818166b7a9563b93f7099f6f0f4caa6cf63b88e8d3e7"
ALGORITHM = "HS256"
ACCESS_TOKEN_EXPIRE_MINUTES = 30


fake_users_db = {
    "johndoe": {
        "username": "johndoe",
        "full_name": "John Doe",
        "email": "johndoe@example.com",
        "hashed_password": "$argon2id$v=19$m=65536,t=3,p=4$wagCPXjifgvUFBzq4hqe3w$CYaIb8sB+wtD+Vu/P4uod1+Qof8h+1g7bbDlBID48Rc",
        "disabled": False,
    },
    "alice": {
        "username": "alice",
        "full_name": "Alice Chains",
        "email": "alicechains@example.com",
        "hashed_password": "$argon2id$v=19$m=65536,t=3,p=4$g2/AV1zwopqUntPKJavBFw$BwpRGDCyUHLvHICnwijyX8ROGoiUPwNKZ7915MeYfCE",
        "disabled": True,
    },
}


class Token(BaseModel):
    access_token: str
    token_type: str


class TokenData(BaseModel):
    username: str | None = None
    scopes: list[str] = []


class User(BaseModel):
    username: str
    email: str | None = None
    full_name: str | None = None
    disabled: bool | None = None


class UserInDB(User):
    hashed_password: str


password_hash = PasswordHash.recommended()

oauth2_scheme = OAuth2PasswordBearer(
    tokenUrl="token",
    scopes={"me": "Read information about the current user.", "items": "Read items."},
)

app = FastAPI()


def verify_password(plain_password, hashed_password):
    return password_hash.verify(plain_password, hashed_password)


def get_password_hash(password):
    return password_hash.hash(password)


def get_user(db, username: str):
    if username in db:
        user_dict = db[username]
        return UserInDB(**user_dict)


def authenticate_user(fake_db, username: str, password: str):
    user = get_user(fake_db, username)
    if not user:
        return False
    if not verify_password(password, user.hashed_password):
        return False
    return user


def create_access_token(data: dict, expires_delta: timedelta | None = None):
    to_encode = data.copy()
    if expires_delta:
        expire = datetime.now(timezone.utc) + expires_delta
    else:
        expire = datetime.now(timezone.utc) + timedelta(minutes=15)
    to_encode.update({"exp": expire})
    encoded_jwt = jwt.encode(to_encode, SECRET_KEY, algorithm=ALGORITHM)
    return encoded_jwt


async def get_current_user(
    security_scopes: SecurityScopes, token: Annotated[str, Depends(oauth2_scheme)]
):
    if security_scopes.scopes:
        authenticate_value = f'Bearer scope="{security_scopes.scope_str}"'
    else:
        authenticate_value = "Bearer"
    credentials_exception = HTTPException(
        status_code=status.HTTP_401_UNAUTHORIZED,
        detail="Could not validate credentials",
        headers={"WWW-Authenticate": authenticate_value},
    )
    try:
        payload = jwt.decode(token, SECRET_KEY, algorithms=[ALGORITHM])
        username = payload.get("sub")
        if username is None:
            raise credentials_exception
        scope: str = payload.get("scope", "")
        token_scopes = scope.split(" ")
        token_data = TokenData(scopes=token_scopes, username=username)
    except (InvalidTokenError, ValidationError):
        raise credentials_exception
    user = get_user(fake_users_db, username=token_data.username)
    if user is None:
        raise credentials_exception
    for scope in security_scopes.scopes:
        if scope not in token_data.scopes:
            raise HTTPException(
                status_code=status.HTTP_401_UNAUTHORIZED,
                detail="Not enough permissions",
                headers={"WWW-Authenticate": authenticate_value},
            )
    return user


async def get_current_active_user(
    current_user: Annotated[User, Security(get_current_user, scopes=["me"])],
):
    if current_user.disabled:
        raise HTTPException(status_code=400, detail="Inactive user")
    return current_user


@app.post("/token")
async def login_for_access_token(
    form_data: Annotated[OAuth2PasswordRequestForm, Depends()],
) -> Token:
    user = authenticate_user(fake_users_db, form_data.username, form_data.password)
    if not user:
        raise HTTPException(status_code=400, detail="Incorrect username or password")
    access_token_expires = timedelta(minutes=ACCESS_TOKEN_EXPIRE_MINUTES)
    access_token = create_access_token(
        data={"sub": user.username, "scope": " ".join(form_data.scopes)},
        expires_delta=access_token_expires,
    )
    return Token(access_token=access_token, token_type="bearer")


@app.get("/users/me/", response_model=User)
async def read_users_me(
    current_user: Annotated[User, Depends(get_current_active_user)],
):
    return current_user


@app.get("/users/me/items/")
async def read_own_items(
    current_user: Annotated[User, Security(get_current_active_user, scopes=["items"])],
):
    return [{"item_id": "Foo", "owner": current_user.username}]


@app.get("/status/")
async def read_system_status(current_user: Annotated[User, Depends(get_current_user)]):
    return {"status": "ok"}

🤓 その他のバージョンとバリアント

Python 3.9+Python 3.8+Python 3.10+ - non-AnnotatedPython 3.9+ - 非注釈付きPython 3.8+ - non-Annotated

from datetime import datetime, timedelta, timezone
from typing import Annotated, Union

import jwt
from fastapi import Depends, FastAPI, HTTPException, Security, status
from fastapi.security import (
    OAuth2PasswordBearer,
    OAuth2PasswordRequestForm,
    SecurityScopes,
)
from jwt.exceptions import InvalidTokenError
from pwdlib import PasswordHash
from pydantic import BaseModel, ValidationError

# to get a string like this run:
# openssl rand -hex 32
SECRET_KEY = "09d25e094faa6ca2556c818166b7a9563b93f7099f6f0f4caa6cf63b88e8d3e7"
ALGORITHM = "HS256"
ACCESS_TOKEN_EXPIRE_MINUTES = 30


fake_users_db = {
    "johndoe": {
        "username": "johndoe",
        "full_name": "John Doe",
        "email": "johndoe@example.com",
        "hashed_password": "$argon2id$v=19$m=65536,t=3,p=4$wagCPXjifgvUFBzq4hqe3w$CYaIb8sB+wtD+Vu/P4uod1+Qof8h+1g7bbDlBID48Rc",
        "disabled": False,
    },
    "alice": {
        "username": "alice",
        "full_name": "Alice Chains",
        "email": "alicechains@example.com",
        "hashed_password": "$argon2id$v=19$m=65536,t=3,p=4$g2/AV1zwopqUntPKJavBFw$BwpRGDCyUHLvHICnwijyX8ROGoiUPwNKZ7915MeYfCE",
        "disabled": True,
    },
}


class Token(BaseModel):
    access_token: str
    token_type: str


class TokenData(BaseModel):
    username: Union[str, None] = None
    scopes: list[str] = []


class User(BaseModel):
    username: str
    email: Union[str, None] = None
    full_name: Union[str, None] = None
    disabled: Union[bool, None] = None


class UserInDB(User):
    hashed_password: str


password_hash = PasswordHash.recommended()

oauth2_scheme = OAuth2PasswordBearer(
    tokenUrl="token",
    scopes={"me": "Read information about the current user.", "items": "Read items."},
)

app = FastAPI()


def verify_password(plain_password, hashed_password):
    return password_hash.verify(plain_password, hashed_password)


def get_password_hash(password):
    return password_hash.hash(password)


def get_user(db, username: str):
    if username in db:
        user_dict = db[username]
        return UserInDB(**user_dict)


def authenticate_user(fake_db, username: str, password: str):
    user = get_user(fake_db, username)
    if not user:
        return False
    if not verify_password(password, user.hashed_password):
        return False
    return user


def create_access_token(data: dict, expires_delta: Union[timedelta, None] = None):
    to_encode = data.copy()
    if expires_delta:
        expire = datetime.now(timezone.utc) + expires_delta
    else:
        expire = datetime.now(timezone.utc) + timedelta(minutes=15)
    to_encode.update({"exp": expire})
    encoded_jwt = jwt.encode(to_encode, SECRET_KEY, algorithm=ALGORITHM)
    return encoded_jwt


async def get_current_user(
    security_scopes: SecurityScopes, token: Annotated[str, Depends(oauth2_scheme)]
):
    if security_scopes.scopes:
        authenticate_value = f'Bearer scope="{security_scopes.scope_str}"'
    else:
        authenticate_value = "Bearer"
    credentials_exception = HTTPException(
        status_code=status.HTTP_401_UNAUTHORIZED,
        detail="Could not validate credentials",
        headers={"WWW-Authenticate": authenticate_value},
    )
    try:
        payload = jwt.decode(token, SECRET_KEY, algorithms=[ALGORITHM])
        username = payload.get("sub")
        if username is None:
            raise credentials_exception
        scope: str = payload.get("scope", "")
        token_scopes = scope.split(" ")
        token_data = TokenData(scopes=token_scopes, username=username)
    except (InvalidTokenError, ValidationError):
        raise credentials_exception
    user = get_user(fake_users_db, username=token_data.username)
    if user is None:
        raise credentials_exception
    for scope in security_scopes.scopes:
        if scope not in token_data.scopes:
            raise HTTPException(
                status_code=status.HTTP_401_UNAUTHORIZED,
                detail="Not enough permissions",
                headers={"WWW-Authenticate": authenticate_value},
            )
    return user


async def get_current_active_user(
    current_user: Annotated[User, Security(get_current_user, scopes=["me"])],
):
    if current_user.disabled:
        raise HTTPException(status_code=400, detail="Inactive user")
    return current_user


@app.post("/token")
async def login_for_access_token(
    form_data: Annotated[OAuth2PasswordRequestForm, Depends()],
) -> Token:
    user = authenticate_user(fake_users_db, form_data.username, form_data.password)
    if not user:
        raise HTTPException(status_code=400, detail="Incorrect username or password")
    access_token_expires = timedelta(minutes=ACCESS_TOKEN_EXPIRE_MINUTES)
    access_token = create_access_token(
        data={"sub": user.username, "scope": " ".join(form_data.scopes)},
        expires_delta=access_token_expires,
    )
    return Token(access_token=access_token, token_type="bearer")


@app.get("/users/me/", response_model=User)
async def read_users_me(
    current_user: Annotated[User, Depends(get_current_active_user)],
):
    return current_user


@app.get("/users/me/items/")
async def read_own_items(
    current_user: Annotated[User, Security(get_current_active_user, scopes=["items"])],
):
    return [{"item_id": "Foo", "owner": current_user.username}]


@app.get("/status/")
async def read_system_status(current_user: Annotated[User, Depends(get_current_user)]):
    return {"status": "ok"}

from datetime import datetime, timedelta, timezone
from typing import List, Union

import jwt
from fastapi import Depends, FastAPI, HTTPException, Security, status
from fastapi.security import (
    OAuth2PasswordBearer,
    OAuth2PasswordRequestForm,
    SecurityScopes,
)
from jwt.exceptions import InvalidTokenError
from pwdlib import PasswordHash
from pydantic import BaseModel, ValidationError
from typing_extensions import Annotated

# to get a string like this run:
# openssl rand -hex 32
SECRET_KEY = "09d25e094faa6ca2556c818166b7a9563b93f7099f6f0f4caa6cf63b88e8d3e7"
ALGORITHM = "HS256"
ACCESS_TOKEN_EXPIRE_MINUTES = 30


fake_users_db = {
    "johndoe": {
        "username": "johndoe",
        "full_name": "John Doe",
        "email": "johndoe@example.com",
        "hashed_password": "$argon2id$v=19$m=65536,t=3,p=4$wagCPXjifgvUFBzq4hqe3w$CYaIb8sB+wtD+Vu/P4uod1+Qof8h+1g7bbDlBID48Rc",
        "disabled": False,
    },
    "alice": {
        "username": "alice",
        "full_name": "Alice Chains",
        "email": "alicechains@example.com",
        "hashed_password": "$argon2id$v=19$m=65536,t=3,p=4$g2/AV1zwopqUntPKJavBFw$BwpRGDCyUHLvHICnwijyX8ROGoiUPwNKZ7915MeYfCE",
        "disabled": True,
    },
}


class Token(BaseModel):
    access_token: str
    token_type: str


class TokenData(BaseModel):
    username: Union[str, None] = None
    scopes: List[str] = []


class User(BaseModel):
    username: str
    email: Union[str, None] = None
    full_name: Union[str, None] = None
    disabled: Union[bool, None] = None


class UserInDB(User):
    hashed_password: str


password_hash = PasswordHash.recommended()

oauth2_scheme = OAuth2PasswordBearer(
    tokenUrl="token",
    scopes={"me": "Read information about the current user.", "items": "Read items."},
)

app = FastAPI()


def verify_password(plain_password, hashed_password):
    return password_hash.verify(plain_password, hashed_password)


def get_password_hash(password):
    return password_hash.hash(password)


def get_user(db, username: str):
    if username in db:
        user_dict = db[username]
        return UserInDB(**user_dict)


def authenticate_user(fake_db, username: str, password: str):
    user = get_user(fake_db, username)
    if not user:
        return False
    if not verify_password(password, user.hashed_password):
        return False
    return user


def create_access_token(data: dict, expires_delta: Union[timedelta, None] = None):
    to_encode = data.copy()
    if expires_delta:
        expire = datetime.now(timezone.utc) + expires_delta
    else:
        expire = datetime.now(timezone.utc) + timedelta(minutes=15)
    to_encode.update({"exp": expire})
    encoded_jwt = jwt.encode(to_encode, SECRET_KEY, algorithm=ALGORITHM)
    return encoded_jwt


async def get_current_user(
    security_scopes: SecurityScopes, token: Annotated[str, Depends(oauth2_scheme)]
):
    if security_scopes.scopes:
        authenticate_value = f'Bearer scope="{security_scopes.scope_str}"'
    else:
        authenticate_value = "Bearer"
    credentials_exception = HTTPException(
        status_code=status.HTTP_401_UNAUTHORIZED,
        detail="Could not validate credentials",
        headers={"WWW-Authenticate": authenticate_value},
    )
    try:
        payload = jwt.decode(token, SECRET_KEY, algorithms=[ALGORITHM])
        username = payload.get("sub")
        if username is None:
            raise credentials_exception
        scope: str = payload.get("scope", "")
        token_scopes = scope.split(" ")
        token_data = TokenData(scopes=token_scopes, username=username)
    except (InvalidTokenError, ValidationError):
        raise credentials_exception
    user = get_user(fake_users_db, username=token_data.username)
    if user is None:
        raise credentials_exception
    for scope in security_scopes.scopes:
        if scope not in token_data.scopes:
            raise HTTPException(
                status_code=status.HTTP_401_UNAUTHORIZED,
                detail="Not enough permissions",
                headers={"WWW-Authenticate": authenticate_value},
            )
    return user


async def get_current_active_user(
    current_user: Annotated[User, Security(get_current_user, scopes=["me"])],
):
    if current_user.disabled:
        raise HTTPException(status_code=400, detail="Inactive user")
    return current_user


@app.post("/token")
async def login_for_access_token(
    form_data: Annotated[OAuth2PasswordRequestForm, Depends()],
) -> Token:
    user = authenticate_user(fake_users_db, form_data.username, form_data.password)
    if not user:
        raise HTTPException(status_code=400, detail="Incorrect username or password")
    access_token_expires = timedelta(minutes=ACCESS_TOKEN_EXPIRE_MINUTES)
    access_token = create_access_token(
        data={"sub": user.username, "scope": " ".join(form_data.scopes)},
        expires_delta=access_token_expires,
    )
    return Token(access_token=access_token, token_type="bearer")


@app.get("/users/me/", response_model=User)
async def read_users_me(
    current_user: Annotated[User, Depends(get_current_active_user)],
):
    return current_user


@app.get("/users/me/items/")
async def read_own_items(
    current_user: Annotated[User, Security(get_current_active_user, scopes=["items"])],
):
    return [{"item_id": "Foo", "owner": current_user.username}]


@app.get("/status/")
async def read_system_status(current_user: Annotated[User, Depends(get_current_user)]):
    return {"status": "ok"}

ヒント

可能であれば`Annotated`バージョンを使用することをお勧めします。

from datetime import datetime, timedelta, timezone

import jwt
from fastapi import Depends, FastAPI, HTTPException, Security, status
from fastapi.security import (
    OAuth2PasswordBearer,
    OAuth2PasswordRequestForm,
    SecurityScopes,
)
from jwt.exceptions import InvalidTokenError
from pwdlib import PasswordHash
from pydantic import BaseModel, ValidationError

# to get a string like this run:
# openssl rand -hex 32
SECRET_KEY = "09d25e094faa6ca2556c818166b7a9563b93f7099f6f0f4caa6cf63b88e8d3e7"
ALGORITHM = "HS256"
ACCESS_TOKEN_EXPIRE_MINUTES = 30


fake_users_db = {
    "johndoe": {
        "username": "johndoe",
        "full_name": "John Doe",
        "email": "johndoe@example.com",
        "hashed_password": "$argon2id$v=19$m=65536,t=3,p=4$wagCPXjifgvUFBzq4hqe3w$CYaIb8sB+wtD+Vu/P4uod1+Qof8h+1g7bbDlBID48Rc",
        "disabled": False,
    },
    "alice": {
        "username": "alice",
        "full_name": "Alice Chains",
        "email": "alicechains@example.com",
        "hashed_password": "$argon2id$v=19$m=65536,t=3,p=4$g2/AV1zwopqUntPKJavBFw$BwpRGDCyUHLvHICnwijyX8ROGoiUPwNKZ7915MeYfCE",
        "disabled": True,
    },
}


class Token(BaseModel):
    access_token: str
    token_type: str


class TokenData(BaseModel):
    username: str | None = None
    scopes: list[str] = []


class User(BaseModel):
    username: str
    email: str | None = None
    full_name: str | None = None
    disabled: bool | None = None


class UserInDB(User):
    hashed_password: str


password_hash = PasswordHash.recommended()

oauth2_scheme = OAuth2PasswordBearer(
    tokenUrl="token",
    scopes={"me": "Read information about the current user.", "items": "Read items."},
)

app = FastAPI()


def verify_password(plain_password, hashed_password):
    return password_hash.verify(plain_password, hashed_password)


def get_password_hash(password):
    return password_hash.hash(password)


def get_user(db, username: str):
    if username in db:
        user_dict = db[username]
        return UserInDB(**user_dict)


def authenticate_user(fake_db, username: str, password: str):
    user = get_user(fake_db, username)
    if not user:
        return False
    if not verify_password(password, user.hashed_password):
        return False
    return user


def create_access_token(data: dict, expires_delta: timedelta | None = None):
    to_encode = data.copy()
    if expires_delta:
        expire = datetime.now(timezone.utc) + expires_delta
    else:
        expire = datetime.now(timezone.utc) + timedelta(minutes=15)
    to_encode.update({"exp": expire})
    encoded_jwt = jwt.encode(to_encode, SECRET_KEY, algorithm=ALGORITHM)
    return encoded_jwt


async def get_current_user(
    security_scopes: SecurityScopes, token: str = Depends(oauth2_scheme)
):
    if security_scopes.scopes:
        authenticate_value = f'Bearer scope="{security_scopes.scope_str}"'
    else:
        authenticate_value = "Bearer"
    credentials_exception = HTTPException(
        status_code=status.HTTP_401_UNAUTHORIZED,
        detail="Could not validate credentials",
        headers={"WWW-Authenticate": authenticate_value},
    )
    try:
        payload = jwt.decode(token, SECRET_KEY, algorithms=[ALGORITHM])
        username: str = payload.get("sub")
        if username is None:
            raise credentials_exception
        scope: str = payload.get("scope", "")
        token_scopes = scope.split(" ")
        token_data = TokenData(scopes=token_scopes, username=username)
    except (InvalidTokenError, ValidationError):
        raise credentials_exception
    user = get_user(fake_users_db, username=token_data.username)
    if user is None:
        raise credentials_exception
    for scope in security_scopes.scopes:
        if scope not in token_data.scopes:
            raise HTTPException(
                status_code=status.HTTP_401_UNAUTHORIZED,
                detail="Not enough permissions",
                headers={"WWW-Authenticate": authenticate_value},
            )
    return user


async def get_current_active_user(
    current_user: User = Security(get_current_user, scopes=["me"]),
):
    if current_user.disabled:
        raise HTTPException(status_code=400, detail="Inactive user")
    return current_user


@app.post("/token")
async def login_for_access_token(
    form_data: OAuth2PasswordRequestForm = Depends(),
) -> Token:
    user = authenticate_user(fake_users_db, form_data.username, form_data.password)
    if not user:
        raise HTTPException(status_code=400, detail="Incorrect username or password")
    access_token_expires = timedelta(minutes=ACCESS_TOKEN_EXPIRE_MINUTES)
    access_token = create_access_token(
        data={"sub": user.username, "scope": " ".join(form_data.scopes)},
        expires_delta=access_token_expires,
    )
    return Token(access_token=access_token, token_type="bearer")


@app.get("/users/me/", response_model=User)
async def read_users_me(current_user: User = Depends(get_current_active_user)):
    return current_user


@app.get("/users/me/items/")
async def read_own_items(
    current_user: User = Security(get_current_active_user, scopes=["items"]),
):
    return [{"item_id": "Foo", "owner": current_user.username}]


@app.get("/status/")
async def read_system_status(current_user: User = Depends(get_current_user)):
    return {"status": "ok"}

ヒント

可能であれば`Annotated`バージョンを使用することをお勧めします。

from datetime import datetime, timedelta, timezone
from typing import Union

import jwt
from fastapi import Depends, FastAPI, HTTPException, Security, status
from fastapi.security import (
    OAuth2PasswordBearer,
    OAuth2PasswordRequestForm,
    SecurityScopes,
)
from jwt.exceptions import InvalidTokenError
from pwdlib import PasswordHash
from pydantic import BaseModel, ValidationError

# to get a string like this run:
# openssl rand -hex 32
SECRET_KEY = "09d25e094faa6ca2556c818166b7a9563b93f7099f6f0f4caa6cf63b88e8d3e7"
ALGORITHM = "HS256"
ACCESS_TOKEN_EXPIRE_MINUTES = 30


fake_users_db = {
    "johndoe": {
        "username": "johndoe",
        "full_name": "John Doe",
        "email": "johndoe@example.com",
        "hashed_password": "$argon2id$v=19$m=65536,t=3,p=4$wagCPXjifgvUFBzq4hqe3w$CYaIb8sB+wtD+Vu/P4uod1+Qof8h+1g7bbDlBID48Rc",
        "disabled": False,
    },
    "alice": {
        "username": "alice",
        "full_name": "Alice Chains",
        "email": "alicechains@example.com",
        "hashed_password": "$argon2id$v=19$m=65536,t=3,p=4$g2/AV1zwopqUntPKJavBFw$BwpRGDCyUHLvHICnwijyX8ROGoiUPwNKZ7915MeYfCE",
        "disabled": True,
    },
}


class Token(BaseModel):
    access_token: str
    token_type: str


class TokenData(BaseModel):
    username: Union[str, None] = None
    scopes: list[str] = []


class User(BaseModel):
    username: str
    email: Union[str, None] = None
    full_name: Union[str, None] = None
    disabled: Union[bool, None] = None


class UserInDB(User):
    hashed_password: str


password_hash = PasswordHash.recommended()

oauth2_scheme = OAuth2PasswordBearer(
    tokenUrl="token",
    scopes={"me": "Read information about the current user.", "items": "Read items."},
)

app = FastAPI()


def verify_password(plain_password, hashed_password):
    return password_hash.verify(plain_password, hashed_password)


def get_password_hash(password):
    return password_hash.hash(password)


def get_user(db, username: str):
    if username in db:
        user_dict = db[username]
        return UserInDB(**user_dict)


def authenticate_user(fake_db, username: str, password: str):
    user = get_user(fake_db, username)
    if not user:
        return False
    if not verify_password(password, user.hashed_password):
        return False
    return user


def create_access_token(data: dict, expires_delta: Union[timedelta, None] = None):
    to_encode = data.copy()
    if expires_delta:
        expire = datetime.now(timezone.utc) + expires_delta
    else:
        expire = datetime.now(timezone.utc) + timedelta(minutes=15)
    to_encode.update({"exp": expire})
    encoded_jwt = jwt.encode(to_encode, SECRET_KEY, algorithm=ALGORITHM)
    return encoded_jwt


async def get_current_user(
    security_scopes: SecurityScopes, token: str = Depends(oauth2_scheme)
):
    if security_scopes.scopes:
        authenticate_value = f'Bearer scope="{security_scopes.scope_str}"'
    else:
        authenticate_value = "Bearer"
    credentials_exception = HTTPException(
        status_code=status.HTTP_401_UNAUTHORIZED,
        detail="Could not validate credentials",
        headers={"WWW-Authenticate": authenticate_value},
    )
    try:
        payload = jwt.decode(token, SECRET_KEY, algorithms=[ALGORITHM])
        username: str = payload.get("sub")
        if username is None:
            raise credentials_exception
        scope: str = payload.get("scope", "")
        token_scopes = scope.split(" ")
        token_data = TokenData(scopes=token_scopes, username=username)
    except (InvalidTokenError, ValidationError):
        raise credentials_exception
    user = get_user(fake_users_db, username=token_data.username)
    if user is None:
        raise credentials_exception
    for scope in security_scopes.scopes:
        if scope not in token_data.scopes:
            raise HTTPException(
                status_code=status.HTTP_401_UNAUTHORIZED,
                detail="Not enough permissions",
                headers={"WWW-Authenticate": authenticate_value},
            )
    return user


async def get_current_active_user(
    current_user: User = Security(get_current_user, scopes=["me"]),
):
    if current_user.disabled:
        raise HTTPException(status_code=400, detail="Inactive user")
    return current_user


@app.post("/token")
async def login_for_access_token(
    form_data: OAuth2PasswordRequestForm = Depends(),
) -> Token:
    user = authenticate_user(fake_users_db, form_data.username, form_data.password)
    if not user:
        raise HTTPException(status_code=400, detail="Incorrect username or password")
    access_token_expires = timedelta(minutes=ACCESS_TOKEN_EXPIRE_MINUTES)
    access_token = create_access_token(
        data={"sub": user.username, "scope": " ".join(form_data.scopes)},
        expires_delta=access_token_expires,
    )
    return Token(access_token=access_token, token_type="bearer")


@app.get("/users/me/", response_model=User)
async def read_users_me(current_user: User = Depends(get_current_active_user)):
    return current_user


@app.get("/users/me/items/")
async def read_own_items(
    current_user: User = Security(get_current_active_user, scopes=["items"]),
):
    return [{"item_id": "Foo", "owner": current_user.username}]


@app.get("/status/")
async def read_system_status(current_user: User = Depends(get_current_user)):
    return {"status": "ok"}

ヒント

可能であれば`Annotated`バージョンを使用することをお勧めします。

from datetime import datetime, timedelta, timezone
from typing import List, Union

import jwt
from fastapi import Depends, FastAPI, HTTPException, Security, status
from fastapi.security import (
    OAuth2PasswordBearer,
    OAuth2PasswordRequestForm,
    SecurityScopes,
)
from jwt.exceptions import InvalidTokenError
from pwdlib import PasswordHash
from pydantic import BaseModel, ValidationError

# to get a string like this run:
# openssl rand -hex 32
SECRET_KEY = "09d25e094faa6ca2556c818166b7a9563b93f7099f6f0f4caa6cf63b88e8d3e7"
ALGORITHM = "HS256"
ACCESS_TOKEN_EXPIRE_MINUTES = 30


fake_users_db = {
    "johndoe": {
        "username": "johndoe",
        "full_name": "John Doe",
        "email": "johndoe@example.com",
        "hashed_password": "$argon2id$v=19$m=65536,t=3,p=4$wagCPXjifgvUFBzq4hqe3w$CYaIb8sB+wtD+Vu/P4uod1+Qof8h+1g7bbDlBID48Rc",
        "disabled": False,
    },
    "alice": {
        "username": "alice",
        "full_name": "Alice Chains",
        "email": "alicechains@example.com",
        "hashed_password": "$argon2id$v=19$m=65536,t=3,p=4$g2/AV1zwopqUntPKJavBFw$BwpRGDCyUHLvHICnwijyX8ROGoiUPwNKZ7915MeYfCE",
        "disabled": True,
    },
}


class Token(BaseModel):
    access_token: str
    token_type: str


class TokenData(BaseModel):
    username: Union[str, None] = None
    scopes: List[str] = []


class User(BaseModel):
    username: str
    email: Union[str, None] = None
    full_name: Union[str, None] = None
    disabled: Union[bool, None] = None


class UserInDB(User):
    hashed_password: str


password_hash = PasswordHash.recommended()

oauth2_scheme = OAuth2PasswordBearer(
    tokenUrl="token",
    scopes={"me": "Read information about the current user.", "items": "Read items."},
)

app = FastAPI()


def verify_password(plain_password, hashed_password):
    return password_hash.verify(plain_password, hashed_password)


def get_password_hash(password):
    return password_hash.hash(password)


def get_user(db, username: str):
    if username in db:
        user_dict = db[username]
        return UserInDB(**user_dict)


def authenticate_user(fake_db, username: str, password: str):
    user = get_user(fake_db, username)
    if not user:
        return False
    if not verify_password(password, user.hashed_password):
        return False
    return user


def create_access_token(data: dict, expires_delta: Union[timedelta, None] = None):
    to_encode = data.copy()
    if expires_delta:
        expire = datetime.now(timezone.utc) + expires_delta
    else:
        expire = datetime.now(timezone.utc) + timedelta(minutes=15)
    to_encode.update({"exp": expire})
    encoded_jwt = jwt.encode(to_encode, SECRET_KEY, algorithm=ALGORITHM)
    return encoded_jwt


async def get_current_user(
    security_scopes: SecurityScopes, token: str = Depends(oauth2_scheme)
):
    if security_scopes.scopes:
        authenticate_value = f'Bearer scope="{security_scopes.scope_str}"'
    else:
        authenticate_value = "Bearer"
    credentials_exception = HTTPException(
        status_code=status.HTTP_401_UNAUTHORIZED,
        detail="Could not validate credentials",
        headers={"WWW-Authenticate": authenticate_value},
    )
    try:
        payload = jwt.decode(token, SECRET_KEY, algorithms=[ALGORITHM])
        username: str = payload.get("sub")
        if username is None:
            raise credentials_exception
        scope: str = payload.get("scope", "")
        token_scopes = scope.split(" ")
        token_data = TokenData(scopes=token_scopes, username=username)
    except (InvalidTokenError, ValidationError):
        raise credentials_exception
    user = get_user(fake_users_db, username=token_data.username)
    if user is None:
        raise credentials_exception
    for scope in security_scopes.scopes:
        if scope not in token_data.scopes:
            raise HTTPException(
                status_code=status.HTTP_401_UNAUTHORIZED,
                detail="Not enough permissions",
                headers={"WWW-Authenticate": authenticate_value},
            )
    return user


async def get_current_active_user(
    current_user: User = Security(get_current_user, scopes=["me"]),
):
    if current_user.disabled:
        raise HTTPException(status_code=400, detail="Inactive user")
    return current_user


@app.post("/token")
async def login_for_access_token(
    form_data: OAuth2PasswordRequestForm = Depends(),
) -> Token:
    user = authenticate_user(fake_users_db, form_data.username, form_data.password)
    if not user:
        raise HTTPException(status_code=400, detail="Incorrect username or password")
    access_token_expires = timedelta(minutes=ACCESS_TOKEN_EXPIRE_MINUTES)
    access_token = create_access_token(
        data={"sub": user.username, "scope": " ".join(form_data.scopes)},
        expires_delta=access_token_expires,
    )
    return Token(access_token=access_token, token_type="bearer")


@app.get("/users/me/", response_model=User)
async def read_users_me(current_user: User = Depends(get_current_active_user)):
    return current_user


@app.get("/users/me/items/")
async def read_own_items(
    current_user: User = Security(get_current_active_user, scopes=["items"]),
):
    return [{"item_id": "Foo", "owner": current_user.username}]


@app.get("/status/")
async def read_system_status(current_user: User = Depends(get_current_user)):
    return {"status": "ok"}

パス操作と依存関係でスコープを宣言する

次に、/users/me/items/のパス操作がスコープitemsを必要とすることを宣言します。

このため、fastapiからSecurityをインポートして使用します。

Securityは依存関係を宣言するために使用できます（Dependsと同様に）。しかし、Securityはスコープのリスト（文字列）をscopesパラメータとして受け取ります。

この場合、依存関数get_current_active_userをSecurityに渡します（Dependsを使用する場合と同様です）。

しかし、スコープのlistも渡します。この場合はitemsという1つのスコープだけです（複数持つことも可能です）。

そして、依存関数get_current_active_userは、DependsだけでなくSecurityでもサブ依存関係を宣言できます。独自のサブ依存関数（get_current_user）と、さらなるスコープ要件を宣言します。

この場合、スコープmeを必要とします（複数のスコープを必要とすることもあります）。

Note

異なる場所に異なるスコープを追加する必要は必ずしもありません。

ここでは、FastAPIが異なるレベルで宣言されたスコープをどのように処理するかを示すために行っています。

Python 3.10+

from datetime import datetime, timedelta, timezone
from typing import Annotated

import jwt
from fastapi import Depends, FastAPI, HTTPException, Security, status
from fastapi.security import (
    OAuth2PasswordBearer,
    OAuth2PasswordRequestForm,
    SecurityScopes,
)
from jwt.exceptions import InvalidTokenError
from pwdlib import PasswordHash
from pydantic import BaseModel, ValidationError

# to get a string like this run:
# openssl rand -hex 32
SECRET_KEY = "09d25e094faa6ca2556c818166b7a9563b93f7099f6f0f4caa6cf63b88e8d3e7"
ALGORITHM = "HS256"
ACCESS_TOKEN_EXPIRE_MINUTES = 30


fake_users_db = {
    "johndoe": {
        "username": "johndoe",
        "full_name": "John Doe",
        "email": "johndoe@example.com",
        "hashed_password": "$argon2id$v=19$m=65536,t=3,p=4$wagCPXjifgvUFBzq4hqe3w$CYaIb8sB+wtD+Vu/P4uod1+Qof8h+1g7bbDlBID48Rc",
        "disabled": False,
    },
    "alice": {
        "username": "alice",
        "full_name": "Alice Chains",
        "email": "alicechains@example.com",
        "hashed_password": "$argon2id$v=19$m=65536,t=3,p=4$g2/AV1zwopqUntPKJavBFw$BwpRGDCyUHLvHICnwijyX8ROGoiUPwNKZ7915MeYfCE",
        "disabled": True,
    },
}


class Token(BaseModel):
    access_token: str
    token_type: str


class TokenData(BaseModel):
    username: str | None = None
    scopes: list[str] = []


class User(BaseModel):
    username: str
    email: str | None = None
    full_name: str | None = None
    disabled: bool | None = None


class UserInDB(User):
    hashed_password: str


password_hash = PasswordHash.recommended()

oauth2_scheme = OAuth2PasswordBearer(
    tokenUrl="token",
    scopes={"me": "Read information about the current user.", "items": "Read items."},
)

app = FastAPI()


def verify_password(plain_password, hashed_password):
    return password_hash.verify(plain_password, hashed_password)


def get_password_hash(password):
    return password_hash.hash(password)


def get_user(db, username: str):
    if username in db:
        user_dict = db[username]
        return UserInDB(**user_dict)


def authenticate_user(fake_db, username: str, password: str):
    user = get_user(fake_db, username)
    if not user:
        return False
    if not verify_password(password, user.hashed_password):
        return False
    return user


def create_access_token(data: dict, expires_delta: timedelta | None = None):
    to_encode = data.copy()
    if expires_delta:
        expire = datetime.now(timezone.utc) + expires_delta
    else:
        expire = datetime.now(timezone.utc) + timedelta(minutes=15)
    to_encode.update({"exp": expire})
    encoded_jwt = jwt.encode(to_encode, SECRET_KEY, algorithm=ALGORITHM)
    return encoded_jwt


async def get_current_user(
    security_scopes: SecurityScopes, token: Annotated[str, Depends(oauth2_scheme)]
):
    if security_scopes.scopes:
        authenticate_value = f'Bearer scope="{security_scopes.scope_str}"'
    else:
        authenticate_value = "Bearer"
    credentials_exception = HTTPException(
        status_code=status.HTTP_401_UNAUTHORIZED,
        detail="Could not validate credentials",
        headers={"WWW-Authenticate": authenticate_value},
    )
    try:
        payload = jwt.decode(token, SECRET_KEY, algorithms=[ALGORITHM])
        username = payload.get("sub")
        if username is None:
            raise credentials_exception
        scope: str = payload.get("scope", "")
        token_scopes = scope.split(" ")
        token_data = TokenData(scopes=token_scopes, username=username)
    except (InvalidTokenError, ValidationError):
        raise credentials_exception
    user = get_user(fake_users_db, username=token_data.username)
    if user is None:
        raise credentials_exception
    for scope in security_scopes.scopes:
        if scope not in token_data.scopes:
            raise HTTPException(
                status_code=status.HTTP_401_UNAUTHORIZED,
                detail="Not enough permissions",
                headers={"WWW-Authenticate": authenticate_value},
            )
    return user


async def get_current_active_user(
    current_user: Annotated[User, Security(get_current_user, scopes=["me"])],
):
    if current_user.disabled:
        raise HTTPException(status_code=400, detail="Inactive user")
    return current_user


@app.post("/token")
async def login_for_access_token(
    form_data: Annotated[OAuth2PasswordRequestForm, Depends()],
) -> Token:
    user = authenticate_user(fake_users_db, form_data.username, form_data.password)
    if not user:
        raise HTTPException(status_code=400, detail="Incorrect username or password")
    access_token_expires = timedelta(minutes=ACCESS_TOKEN_EXPIRE_MINUTES)
    access_token = create_access_token(
        data={"sub": user.username, "scope": " ".join(form_data.scopes)},
        expires_delta=access_token_expires,
    )
    return Token(access_token=access_token, token_type="bearer")


@app.get("/users/me/", response_model=User)
async def read_users_me(
    current_user: Annotated[User, Depends(get_current_active_user)],
):
    return current_user


@app.get("/users/me/items/")
async def read_own_items(
    current_user: Annotated[User, Security(get_current_active_user, scopes=["items"])],
):
    return [{"item_id": "Foo", "owner": current_user.username}]


@app.get("/status/")
async def read_system_status(current_user: Annotated[User, Depends(get_current_user)]):
    return {"status": "ok"}

🤓 その他のバージョンとバリアント

Python 3.9+Python 3.8+Python 3.10+ - non-AnnotatedPython 3.9+ - 非注釈付きPython 3.8+ - non-Annotated

from datetime import datetime, timedelta, timezone
from typing import Annotated, Union

import jwt
from fastapi import Depends, FastAPI, HTTPException, Security, status
from fastapi.security import (
    OAuth2PasswordBearer,
    OAuth2PasswordRequestForm,
    SecurityScopes,
)
from jwt.exceptions import InvalidTokenError
from pwdlib import PasswordHash
from pydantic import BaseModel, ValidationError

# to get a string like this run:
# openssl rand -hex 32
SECRET_KEY = "09d25e094faa6ca2556c818166b7a9563b93f7099f6f0f4caa6cf63b88e8d3e7"
ALGORITHM = "HS256"
ACCESS_TOKEN_EXPIRE_MINUTES = 30


fake_users_db = {
    "johndoe": {
        "username": "johndoe",
        "full_name": "John Doe",
        "email": "johndoe@example.com",
        "hashed_password": "$argon2id$v=19$m=65536,t=3,p=4$wagCPXjifgvUFBzq4hqe3w$CYaIb8sB+wtD+Vu/P4uod1+Qof8h+1g7bbDlBID48Rc",
        "disabled": False,
    },
    "alice": {
        "username": "alice",
        "full_name": "Alice Chains",
        "email": "alicechains@example.com",
        "hashed_password": "$argon2id$v=19$m=65536,t=3,p=4$g2/AV1zwopqUntPKJavBFw$BwpRGDCyUHLvHICnwijyX8ROGoiUPwNKZ7915MeYfCE",
        "disabled": True,
    },
}


class Token(BaseModel):
    access_token: str
    token_type: str


class TokenData(BaseModel):
    username: Union[str, None] = None
    scopes: list[str] = []


class User(BaseModel):
    username: str
    email: Union[str, None] = None
    full_name: Union[str, None] = None
    disabled: Union[bool, None] = None


class UserInDB(User):
    hashed_password: str


password_hash = PasswordHash.recommended()

oauth2_scheme = OAuth2PasswordBearer(
    tokenUrl="token",
    scopes={"me": "Read information about the current user.", "items": "Read items."},
)

app = FastAPI()


def verify_password(plain_password, hashed_password):
    return password_hash.verify(plain_password, hashed_password)


def get_password_hash(password):
    return password_hash.hash(password)


def get_user(db, username: str):
    if username in db:
        user_dict = db[username]
        return UserInDB(**user_dict)


def authenticate_user(fake_db, username: str, password: str):
    user = get_user(fake_db, username)
    if not user:
        return False
    if not verify_password(password, user.hashed_password):
        return False
    return user


def create_access_token(data: dict, expires_delta: Union[timedelta, None] = None):
    to_encode = data.copy()
    if expires_delta:
        expire = datetime.now(timezone.utc) + expires_delta
    else:
        expire = datetime.now(timezone.utc) + timedelta(minutes=15)
    to_encode.update({"exp": expire})
    encoded_jwt = jwt.encode(to_encode, SECRET_KEY, algorithm=ALGORITHM)
    return encoded_jwt


async def get_current_user(
    security_scopes: SecurityScopes, token: Annotated[str, Depends(oauth2_scheme)]
):
    if security_scopes.scopes:
        authenticate_value = f'Bearer scope="{security_scopes.scope_str}"'
    else:
        authenticate_value = "Bearer"
    credentials_exception = HTTPException(
        status_code=status.HTTP_401_UNAUTHORIZED,
        detail="Could not validate credentials",
        headers={"WWW-Authenticate": authenticate_value},
    )
    try:
        payload = jwt.decode(token, SECRET_KEY, algorithms=[ALGORITHM])
        username = payload.get("sub")
        if username is None:
            raise credentials_exception
        scope: str = payload.get("scope", "")
        token_scopes = scope.split(" ")
        token_data = TokenData(scopes=token_scopes, username=username)
    except (InvalidTokenError, ValidationError):
        raise credentials_exception
    user = get_user(fake_users_db, username=token_data.username)
    if user is None:
        raise credentials_exception
    for scope in security_scopes.scopes:
        if scope not in token_data.scopes:
            raise HTTPException(
                status_code=status.HTTP_401_UNAUTHORIZED,
                detail="Not enough permissions",
                headers={"WWW-Authenticate": authenticate_value},
            )
    return user


async def get_current_active_user(
    current_user: Annotated[User, Security(get_current_user, scopes=["me"])],
):
    if current_user.disabled:
        raise HTTPException(status_code=400, detail="Inactive user")
    return current_user


@app.post("/token")
async def login_for_access_token(
    form_data: Annotated[OAuth2PasswordRequestForm, Depends()],
) -> Token:
    user = authenticate_user(fake_users_db, form_data.username, form_data.password)
    if not user:
        raise HTTPException(status_code=400, detail="Incorrect username or password")
    access_token_expires = timedelta(minutes=ACCESS_TOKEN_EXPIRE_MINUTES)
    access_token = create_access_token(
        data={"sub": user.username, "scope": " ".join(form_data.scopes)},
        expires_delta=access_token_expires,
    )
    return Token(access_token=access_token, token_type="bearer")


@app.get("/users/me/", response_model=User)
async def read_users_me(
    current_user: Annotated[User, Depends(get_current_active_user)],
):
    return current_user


@app.get("/users/me/items/")
async def read_own_items(
    current_user: Annotated[User, Security(get_current_active_user, scopes=["items"])],
):
    return [{"item_id": "Foo", "owner": current_user.username}]


@app.get("/status/")
async def read_system_status(current_user: Annotated[User, Depends(get_current_user)]):
    return {"status": "ok"}

from datetime import datetime, timedelta, timezone
from typing import List, Union

import jwt
from fastapi import Depends, FastAPI, HTTPException, Security, status
from fastapi.security import (
    OAuth2PasswordBearer,
    OAuth2PasswordRequestForm,
    SecurityScopes,
)
from jwt.exceptions import InvalidTokenError
from pwdlib import PasswordHash
from pydantic import BaseModel, ValidationError
from typing_extensions import Annotated

# to get a string like this run:
# openssl rand -hex 32
SECRET_KEY = "09d25e094faa6ca2556c818166b7a9563b93f7099f6f0f4caa6cf63b88e8d3e7"
ALGORITHM = "HS256"
ACCESS_TOKEN_EXPIRE_MINUTES = 30


fake_users_db = {
    "johndoe": {
        "username": "johndoe",
        "full_name": "John Doe",
        "email": "johndoe@example.com",
        "hashed_password": "$argon2id$v=19$m=65536,t=3,p=4$wagCPXjifgvUFBzq4hqe3w$CYaIb8sB+wtD+Vu/P4uod1+Qof8h+1g7bbDlBID48Rc",
        "disabled": False,
    },
    "alice": {
        "username": "alice",
        "full_name": "Alice Chains",
        "email": "alicechains@example.com",
        "hashed_password": "$argon2id$v=19$m=65536,t=3,p=4$g2/AV1zwopqUntPKJavBFw$BwpRGDCyUHLvHICnwijyX8ROGoiUPwNKZ7915MeYfCE",
        "disabled": True,
    },
}


class Token(BaseModel):
    access_token: str
    token_type: str


class TokenData(BaseModel):
    username: Union[str, None] = None
    scopes: List[str] = []


class User(BaseModel):
    username: str
    email: Union[str, None] = None
    full_name: Union[str, None] = None
    disabled: Union[bool, None] = None


class UserInDB(User):
    hashed_password: str


password_hash = PasswordHash.recommended()

oauth2_scheme = OAuth2PasswordBearer(
    tokenUrl="token",
    scopes={"me": "Read information about the current user.", "items": "Read items."},
)

app = FastAPI()


def verify_password(plain_password, hashed_password):
    return password_hash.verify(plain_password, hashed_password)


def get_password_hash(password):
    return password_hash.hash(password)


def get_user(db, username: str):
    if username in db:
        user_dict = db[username]
        return UserInDB(**user_dict)


def authenticate_user(fake_db, username: str, password: str):
    user = get_user(fake_db, username)
    if not user:
        return False
    if not verify_password(password, user.hashed_password):
        return False
    return user


def create_access_token(data: dict, expires_delta: Union[timedelta, None] = None):
    to_encode = data.copy()
    if expires_delta:
        expire = datetime.now(timezone.utc) + expires_delta
    else:
        expire = datetime.now(timezone.utc) + timedelta(minutes=15)
    to_encode.update({"exp": expire})
    encoded_jwt = jwt.encode(to_encode, SECRET_KEY, algorithm=ALGORITHM)
    return encoded_jwt


async def get_current_user(
    security_scopes: SecurityScopes, token: Annotated[str, Depends(oauth2_scheme)]
):
    if security_scopes.scopes:
        authenticate_value = f'Bearer scope="{security_scopes.scope_str}"'
    else:
        authenticate_value = "Bearer"
    credentials_exception = HTTPException(
        status_code=status.HTTP_401_UNAUTHORIZED,
        detail="Could not validate credentials",
        headers={"WWW-Authenticate": authenticate_value},
    )
    try:
        payload = jwt.decode(token, SECRET_KEY, algorithms=[ALGORITHM])
        username = payload.get("sub")
        if username is None:
            raise credentials_exception
        scope: str = payload.get("scope", "")
        token_scopes = scope.split(" ")
        token_data = TokenData(scopes=token_scopes, username=username)
    except (InvalidTokenError, ValidationError):
        raise credentials_exception
    user = get_user(fake_users_db, username=token_data.username)
    if user is None:
        raise credentials_exception
    for scope in security_scopes.scopes:
        if scope not in token_data.scopes:
            raise HTTPException(
                status_code=status.HTTP_401_UNAUTHORIZED,
                detail="Not enough permissions",
                headers={"WWW-Authenticate": authenticate_value},
            )
    return user


async def get_current_active_user(
    current_user: Annotated[User, Security(get_current_user, scopes=["me"])],
):
    if current_user.disabled:
        raise HTTPException(status_code=400, detail="Inactive user")
    return current_user


@app.post("/token")
async def login_for_access_token(
    form_data: Annotated[OAuth2PasswordRequestForm, Depends()],
) -> Token:
    user = authenticate_user(fake_users_db, form_data.username, form_data.password)
    if not user:
        raise HTTPException(status_code=400, detail="Incorrect username or password")
    access_token_expires = timedelta(minutes=ACCESS_TOKEN_EXPIRE_MINUTES)
    access_token = create_access_token(
        data={"sub": user.username, "scope": " ".join(form_data.scopes)},
        expires_delta=access_token_expires,
    )
    return Token(access_token=access_token, token_type="bearer")


@app.get("/users/me/", response_model=User)
async def read_users_me(
    current_user: Annotated[User, Depends(get_current_active_user)],
):
    return current_user


@app.get("/users/me/items/")
async def read_own_items(
    current_user: Annotated[User, Security(get_current_active_user, scopes=["items"])],
):
    return [{"item_id": "Foo", "owner": current_user.username}]


@app.get("/status/")
async def read_system_status(current_user: Annotated[User, Depends(get_current_user)]):
    return {"status": "ok"}

ヒント

可能であれば`Annotated`バージョンを使用することをお勧めします。

from datetime import datetime, timedelta, timezone

import jwt
from fastapi import Depends, FastAPI, HTTPException, Security, status
from fastapi.security import (
    OAuth2PasswordBearer,
    OAuth2PasswordRequestForm,
    SecurityScopes,
)
from jwt.exceptions import InvalidTokenError
from pwdlib import PasswordHash
from pydantic import BaseModel, ValidationError

# to get a string like this run:
# openssl rand -hex 32
SECRET_KEY = "09d25e094faa6ca2556c818166b7a9563b93f7099f6f0f4caa6cf63b88e8d3e7"
ALGORITHM = "HS256"
ACCESS_TOKEN_EXPIRE_MINUTES = 30


fake_users_db = {
    "johndoe": {
        "username": "johndoe",
        "full_name": "John Doe",
        "email": "johndoe@example.com",
        "hashed_password": "$argon2id$v=19$m=65536,t=3,p=4$wagCPXjifgvUFBzq4hqe3w$CYaIb8sB+wtD+Vu/P4uod1+Qof8h+1g7bbDlBID48Rc",
        "disabled": False,
    },
    "alice": {
        "username": "alice",
        "full_name": "Alice Chains",
        "email": "alicechains@example.com",
        "hashed_password": "$argon2id$v=19$m=65536,t=3,p=4$g2/AV1zwopqUntPKJavBFw$BwpRGDCyUHLvHICnwijyX8ROGoiUPwNKZ7915MeYfCE",
        "disabled": True,
    },
}


class Token(BaseModel):
    access_token: str
    token_type: str


class TokenData(BaseModel):
    username: str | None = None
    scopes: list[str] = []


class User(BaseModel):
    username: str
    email: str | None = None
    full_name: str | None = None
    disabled: bool | None = None


class UserInDB(User):
    hashed_password: str


password_hash = PasswordHash.recommended()

oauth2_scheme = OAuth2PasswordBearer(
    tokenUrl="token",
    scopes={"me": "Read information about the current user.", "items": "Read items."},
)

app = FastAPI()


def verify_password(plain_password, hashed_password):
    return password_hash.verify(plain_password, hashed_password)


def get_password_hash(password):
    return password_hash.hash(password)


def get_user(db, username: str):
    if username in db:
        user_dict = db[username]
        return UserInDB(**user_dict)


def authenticate_user(fake_db, username: str, password: str):
    user = get_user(fake_db, username)
    if not user:
        return False
    if not verify_password(password, user.hashed_password):
        return False
    return user


def create_access_token(data: dict, expires_delta: timedelta | None = None):
    to_encode = data.copy()
    if expires_delta:
        expire = datetime.now(timezone.utc) + expires_delta
    else:
        expire = datetime.now(timezone.utc) + timedelta(minutes=15)
    to_encode.update({"exp": expire})
    encoded_jwt = jwt.encode(to_encode, SECRET_KEY, algorithm=ALGORITHM)
    return encoded_jwt


async def get_current_user(
    security_scopes: SecurityScopes, token: str = Depends(oauth2_scheme)
):
    if security_scopes.scopes:
        authenticate_value = f'Bearer scope="{security_scopes.scope_str}"'
    else:
        authenticate_value = "Bearer"
    credentials_exception = HTTPException(
        status_code=status.HTTP_401_UNAUTHORIZED,
        detail="Could not validate credentials",
        headers={"WWW-Authenticate": authenticate_value},
    )
    try:
        payload = jwt.decode(token, SECRET_KEY, algorithms=[ALGORITHM])
        username: str = payload.get("sub")
        if username is None:
            raise credentials_exception
        scope: str = payload.get("scope", "")
        token_scopes = scope.split(" ")
        token_data = TokenData(scopes=token_scopes, username=username)
    except (InvalidTokenError, ValidationError):
        raise credentials_exception
    user = get_user(fake_users_db, username=token_data.username)
    if user is None:
        raise credentials_exception
    for scope in security_scopes.scopes:
        if scope not in token_data.scopes:
            raise HTTPException(
                status_code=status.HTTP_401_UNAUTHORIZED,
                detail="Not enough permissions",
                headers={"WWW-Authenticate": authenticate_value},
            )
    return user


async def get_current_active_user(
    current_user: User = Security(get_current_user, scopes=["me"]),
):
    if current_user.disabled:
        raise HTTPException(status_code=400, detail="Inactive user")
    return current_user


@app.post("/token")
async def login_for_access_token(
    form_data: OAuth2PasswordRequestForm = Depends(),
) -> Token:
    user = authenticate_user(fake_users_db, form_data.username, form_data.password)
    if not user:
        raise HTTPException(status_code=400, detail="Incorrect username or password")
    access_token_expires = timedelta(minutes=ACCESS_TOKEN_EXPIRE_MINUTES)
    access_token = create_access_token(
        data={"sub": user.username, "scope": " ".join(form_data.scopes)},
        expires_delta=access_token_expires,
    )
    return Token(access_token=access_token, token_type="bearer")


@app.get("/users/me/", response_model=User)
async def read_users_me(current_user: User = Depends(get_current_active_user)):
    return current_user


@app.get("/users/me/items/")
async def read_own_items(
    current_user: User = Security(get_current_active_user, scopes=["items"]),
):
    return [{"item_id": "Foo", "owner": current_user.username}]


@app.get("/status/")
async def read_system_status(current_user: User = Depends(get_current_user)):
    return {"status": "ok"}

ヒント

可能であれば`Annotated`バージョンを使用することをお勧めします。

from datetime import datetime, timedelta, timezone
from typing import Union

import jwt
from fastapi import Depends, FastAPI, HTTPException, Security, status
from fastapi.security import (
    OAuth2PasswordBearer,
    OAuth2PasswordRequestForm,
    SecurityScopes,
)
from jwt.exceptions import InvalidTokenError
from pwdlib import PasswordHash
from pydantic import BaseModel, ValidationError

# to get a string like this run:
# openssl rand -hex 32
SECRET_KEY = "09d25e094faa6ca2556c818166b7a9563b93f7099f6f0f4caa6cf63b88e8d3e7"
ALGORITHM = "HS256"
ACCESS_TOKEN_EXPIRE_MINUTES = 30


fake_users_db = {
    "johndoe": {
        "username": "johndoe",
        "full_name": "John Doe",
        "email": "johndoe@example.com",
        "hashed_password": "$argon2id$v=19$m=65536,t=3,p=4$wagCPXjifgvUFBzq4hqe3w$CYaIb8sB+wtD+Vu/P4uod1+Qof8h+1g7bbDlBID48Rc",
        "disabled": False,
    },
    "alice": {
        "username": "alice",
        "full_name": "Alice Chains",
        "email": "alicechains@example.com",
        "hashed_password": "$argon2id$v=19$m=65536,t=3,p=4$g2/AV1zwopqUntPKJavBFw$BwpRGDCyUHLvHICnwijyX8ROGoiUPwNKZ7915MeYfCE",
        "disabled": True,
    },
}


class Token(BaseModel):
    access_token: str
    token_type: str


class TokenData(BaseModel):
    username: Union[str, None] = None
    scopes: list[str] = []


class User(BaseModel):
    username: str
    email: Union[str, None] = None
    full_name: Union[str, None] = None
    disabled: Union[bool, None] = None


class UserInDB(User):
    hashed_password: str


password_hash = PasswordHash.recommended()

oauth2_scheme = OAuth2PasswordBearer(
    tokenUrl="token",
    scopes={"me": "Read information about the current user.", "items": "Read items."},
)

app = FastAPI()


def verify_password(plain_password, hashed_password):
    return password_hash.verify(plain_password, hashed_password)


def get_password_hash(password):
    return password_hash.hash(password)


def get_user(db, username: str):
    if username in db:
        user_dict = db[username]
        return UserInDB(**user_dict)


def authenticate_user(fake_db, username: str, password: str):
    user = get_user(fake_db, username)
    if not user:
        return False
    if not verify_password(password, user.hashed_password):
        return False
    return user


def create_access_token(data: dict, expires_delta: Union[timedelta, None] = None):
    to_encode = data.copy()
    if expires_delta:
        expire = datetime.now(timezone.utc) + expires_delta
    else:
        expire = datetime.now(timezone.utc) + timedelta(minutes=15)
    to_encode.update({"exp": expire})
    encoded_jwt = jwt.encode(to_encode, SECRET_KEY, algorithm=ALGORITHM)
    return encoded_jwt


async def get_current_user(
    security_scopes: SecurityScopes, token: str = Depends(oauth2_scheme)
):
    if security_scopes.scopes:
        authenticate_value = f'Bearer scope="{security_scopes.scope_str}"'
    else:
        authenticate_value = "Bearer"
    credentials_exception = HTTPException(
        status_code=status.HTTP_401_UNAUTHORIZED,
        detail="Could not validate credentials",
        headers={"WWW-Authenticate": authenticate_value},
    )
    try:
        payload = jwt.decode(token, SECRET_KEY, algorithms=[ALGORITHM])
        username: str = payload.get("sub")
        if username is None:
            raise credentials_exception
        scope: str = payload.get("scope", "")
        token_scopes = scope.split(" ")
        token_data = TokenData(scopes=token_scopes, username=username)
    except (InvalidTokenError, ValidationError):
        raise credentials_exception
    user = get_user(fake_users_db, username=token_data.username)
    if user is None:
        raise credentials_exception
    for scope in security_scopes.scopes:
        if scope not in token_data.scopes:
            raise HTTPException(
                status_code=status.HTTP_401_UNAUTHORIZED,
                detail="Not enough permissions",
                headers={"WWW-Authenticate": authenticate_value},
            )
    return user


async def get_current_active_user(
    current_user: User = Security(get_current_user, scopes=["me"]),
):
    if current_user.disabled:
        raise HTTPException(status_code=400, detail="Inactive user")
    return current_user


@app.post("/token")
async def login_for_access_token(
    form_data: OAuth2PasswordRequestForm = Depends(),
) -> Token:
    user = authenticate_user(fake_users_db, form_data.username, form_data.password)
    if not user:
        raise HTTPException(status_code=400, detail="Incorrect username or password")
    access_token_expires = timedelta(minutes=ACCESS_TOKEN_EXPIRE_MINUTES)
    access_token = create_access_token(
        data={"sub": user.username, "scope": " ".join(form_data.scopes)},
        expires_delta=access_token_expires,
    )
    return Token(access_token=access_token, token_type="bearer")


@app.get("/users/me/", response_model=User)
async def read_users_me(current_user: User = Depends(get_current_active_user)):
    return current_user


@app.get("/users/me/items/")
async def read_own_items(
    current_user: User = Security(get_current_active_user, scopes=["items"]),
):
    return [{"item_id": "Foo", "owner": current_user.username}]


@app.get("/status/")
async def read_system_status(current_user: User = Depends(get_current_user)):
    return {"status": "ok"}

ヒント

可能であれば`Annotated`バージョンを使用することをお勧めします。

from datetime import datetime, timedelta, timezone
from typing import List, Union

import jwt
from fastapi import Depends, FastAPI, HTTPException, Security, status
from fastapi.security import (
    OAuth2PasswordBearer,
    OAuth2PasswordRequestForm,
    SecurityScopes,
)
from jwt.exceptions import InvalidTokenError
from pwdlib import PasswordHash
from pydantic import BaseModel, ValidationError

# to get a string like this run:
# openssl rand -hex 32
SECRET_KEY = "09d25e094faa6ca2556c818166b7a9563b93f7099f6f0f4caa6cf63b88e8d3e7"
ALGORITHM = "HS256"
ACCESS_TOKEN_EXPIRE_MINUTES = 30


fake_users_db = {
    "johndoe": {
        "username": "johndoe",
        "full_name": "John Doe",
        "email": "johndoe@example.com",
        "hashed_password": "$argon2id$v=19$m=65536,t=3,p=4$wagCPXjifgvUFBzq4hqe3w$CYaIb8sB+wtD+Vu/P4uod1+Qof8h+1g7bbDlBID48Rc",
        "disabled": False,
    },
    "alice": {
        "username": "alice",
        "full_name": "Alice Chains",
        "email": "alicechains@example.com",
        "hashed_password": "$argon2id$v=19$m=65536,t=3,p=4$g2/AV1zwopqUntPKJavBFw$BwpRGDCyUHLvHICnwijyX8ROGoiUPwNKZ7915MeYfCE",
        "disabled": True,
    },
}


class Token(BaseModel):
    access_token: str
    token_type: str


class TokenData(BaseModel):
    username: Union[str, None] = None
    scopes: List[str] = []


class User(BaseModel):
    username: str
    email: Union[str, None] = None
    full_name: Union[str, None] = None
    disabled: Union[bool, None] = None


class UserInDB(User):
    hashed_password: str


password_hash = PasswordHash.recommended()

oauth2_scheme = OAuth2PasswordBearer(
    tokenUrl="token",
    scopes={"me": "Read information about the current user.", "items": "Read items."},
)

app = FastAPI()


def verify_password(plain_password, hashed_password):
    return password_hash.verify(plain_password, hashed_password)


def get_password_hash(password):
    return password_hash.hash(password)


def get_user(db, username: str):
    if username in db:
        user_dict = db[username]
        return UserInDB(**user_dict)


def authenticate_user(fake_db, username: str, password: str):
    user = get_user(fake_db, username)
    if not user:
        return False
    if not verify_password(password, user.hashed_password):
        return False
    return user


def create_access_token(data: dict, expires_delta: Union[timedelta, None] = None):
    to_encode = data.copy()
    if expires_delta:
        expire = datetime.now(timezone.utc) + expires_delta
    else:
        expire = datetime.now(timezone.utc) + timedelta(minutes=15)
    to_encode.update({"exp": expire})
    encoded_jwt = jwt.encode(to_encode, SECRET_KEY, algorithm=ALGORITHM)
    return encoded_jwt


async def get_current_user(
    security_scopes: SecurityScopes, token: str = Depends(oauth2_scheme)
):
    if security_scopes.scopes:
        authenticate_value = f'Bearer scope="{security_scopes.scope_str}"'
    else:
        authenticate_value = "Bearer"
    credentials_exception = HTTPException(
        status_code=status.HTTP_401_UNAUTHORIZED,
        detail="Could not validate credentials",
        headers={"WWW-Authenticate": authenticate_value},
    )
    try:
        payload = jwt.decode(token, SECRET_KEY, algorithms=[ALGORITHM])
        username: str = payload.get("sub")
        if username is None:
            raise credentials_exception
        scope: str = payload.get("scope", "")
        token_scopes = scope.split(" ")
        token_data = TokenData(scopes=token_scopes, username=username)
    except (InvalidTokenError, ValidationError):
        raise credentials_exception
    user = get_user(fake_users_db, username=token_data.username)
    if user is None:
        raise credentials_exception
    for scope in security_scopes.scopes:
        if scope not in token_data.scopes:
            raise HTTPException(
                status_code=status.HTTP_401_UNAUTHORIZED,
                detail="Not enough permissions",
                headers={"WWW-Authenticate": authenticate_value},
            )
    return user


async def get_current_active_user(
    current_user: User = Security(get_current_user, scopes=["me"]),
):
    if current_user.disabled:
        raise HTTPException(status_code=400, detail="Inactive user")
    return current_user


@app.post("/token")
async def login_for_access_token(
    form_data: OAuth2PasswordRequestForm = Depends(),
) -> Token:
    user = authenticate_user(fake_users_db, form_data.username, form_data.password)
    if not user:
        raise HTTPException(status_code=400, detail="Incorrect username or password")
    access_token_expires = timedelta(minutes=ACCESS_TOKEN_EXPIRE_MINUTES)
    access_token = create_access_token(
        data={"sub": user.username, "scope": " ".join(form_data.scopes)},
        expires_delta=access_token_expires,
    )
    return Token(access_token=access_token, token_type="bearer")


@app.get("/users/me/", response_model=User)
async def read_users_me(current_user: User = Depends(get_current_active_user)):
    return current_user


@app.get("/users/me/items/")
async def read_own_items(
    current_user: User = Security(get_current_active_user, scopes=["items"]),
):
    return [{"item_id": "Foo", "owner": current_user.username}]


@app.get("/status/")
async def read_system_status(current_user: User = Depends(get_current_user)):
    return {"status": "ok"}

技術的な詳細

Securityは実際にはDependsのサブクラスであり、後で説明する追加のパラメータが1つだけあります。

しかし、Dependsの代わりにSecurityを使用することで、FastAPIはセキュリティスコープを宣言し、それらを内部的に使用し、OpenAPIでAPIをドキュメント化できることを認識します。

しかし、Query、Path、Depends、Securityなどをfastapiからインポートする場合、それらは実際には特殊なクラスを返す関数です。

SecurityScopesを使用する

次に、依存関係get_current_userを更新します。

これは、上記の依存関係で使用されているものです。

ここで、以前作成したのと同じOAuth2スキームを、依存関係としてoauth2_schemeと宣言して使用しています。

この依存関数自体にはスコープ要件がないため、oauth2_schemeでDependsを使用できます。セキュリティスコープを指定する必要がない場合は、Securityを使用する必要はありません。

また、fastapi.securityからインポートされたSecurityScopes型の特殊なパラメータも宣言します。

このSecurityScopesクラスはRequest（Requestはリクエストオブジェクトを直接取得するために使用されました）と似ています。

Python 3.10+

from datetime import datetime, timedelta, timezone
from typing import Annotated

import jwt
from fastapi import Depends, FastAPI, HTTPException, Security, status
from fastapi.security import (
    OAuth2PasswordBearer,
    OAuth2PasswordRequestForm,
    SecurityScopes,
)
from jwt.exceptions import InvalidTokenError
from pwdlib import PasswordHash
from pydantic import BaseModel, ValidationError

# to get a string like this run:
# openssl rand -hex 32
SECRET_KEY = "09d25e094faa6ca2556c818166b7a9563b93f7099f6f0f4caa6cf63b88e8d3e7"
ALGORITHM = "HS256"
ACCESS_TOKEN_EXPIRE_MINUTES = 30


fake_users_db = {
    "johndoe": {
        "username": "johndoe",
        "full_name": "John Doe",
        "email": "johndoe@example.com",
        "hashed_password": "$argon2id$v=19$m=65536,t=3,p=4$wagCPXjifgvUFBzq4hqe3w$CYaIb8sB+wtD+Vu/P4uod1+Qof8h+1g7bbDlBID48Rc",
        "disabled": False,
    },
    "alice": {
        "username": "alice",
        "full_name": "Alice Chains",
        "email": "alicechains@example.com",
        "hashed_password": "$argon2id$v=19$m=65536,t=3,p=4$g2/AV1zwopqUntPKJavBFw$BwpRGDCyUHLvHICnwijyX8ROGoiUPwNKZ7915MeYfCE",
        "disabled": True,
    },
}


class Token(BaseModel):
    access_token: str
    token_type: str


class TokenData(BaseModel):
    username: str | None = None
    scopes: list[str] = []


class User(BaseModel):
    username: str
    email: str | None = None
    full_name: str | None = None
    disabled: bool | None = None


class UserInDB(User):
    hashed_password: str


password_hash = PasswordHash.recommended()

oauth2_scheme = OAuth2PasswordBearer(
    tokenUrl="token",
    scopes={"me": "Read information about the current user.", "items": "Read items."},
)

app = FastAPI()


def verify_password(plain_password, hashed_password):
    return password_hash.verify(plain_password, hashed_password)


def get_password_hash(password):
    return password_hash.hash(password)


def get_user(db, username: str):
    if username in db:
        user_dict = db[username]
        return UserInDB(**user_dict)


def authenticate_user(fake_db, username: str, password: str):
    user = get_user(fake_db, username)
    if not user:
        return False
    if not verify_password(password, user.hashed_password):
        return False
    return user


def create_access_token(data: dict, expires_delta: timedelta | None = None):
    to_encode = data.copy()
    if expires_delta:
        expire = datetime.now(timezone.utc) + expires_delta
    else:
        expire = datetime.now(timezone.utc) + timedelta(minutes=15)
    to_encode.update({"exp": expire})
    encoded_jwt = jwt.encode(to_encode, SECRET_KEY, algorithm=ALGORITHM)
    return encoded_jwt


async def get_current_user(
    security_scopes: SecurityScopes, token: Annotated[str, Depends(oauth2_scheme)]
):
    if security_scopes.scopes:
        authenticate_value = f'Bearer scope="{security_scopes.scope_str}"'
    else:
        authenticate_value = "Bearer"
    credentials_exception = HTTPException(
        status_code=status.HTTP_401_UNAUTHORIZED,
        detail="Could not validate credentials",
        headers={"WWW-Authenticate": authenticate_value},
    )
    try:
        payload = jwt.decode(token, SECRET_KEY, algorithms=[ALGORITHM])
        username = payload.get("sub")
        if username is None:
            raise credentials_exception
        scope: str = payload.get("scope", "")
        token_scopes = scope.split(" ")
        token_data = TokenData(scopes=token_scopes, username=username)
    except (InvalidTokenError, ValidationError):
        raise credentials_exception
    user = get_user(fake_users_db, username=token_data.username)
    if user is None:
        raise credentials_exception
    for scope in security_scopes.scopes:
        if scope not in token_data.scopes:
            raise HTTPException(
                status_code=status.HTTP_401_UNAUTHORIZED,
                detail="Not enough permissions",
                headers={"WWW-Authenticate": authenticate_value},
            )
    return user


async def get_current_active_user(
    current_user: Annotated[User, Security(get_current_user, scopes=["me"])],
):
    if current_user.disabled:
        raise HTTPException(status_code=400, detail="Inactive user")
    return current_user


@app.post("/token")
async def login_for_access_token(
    form_data: Annotated[OAuth2PasswordRequestForm, Depends()],
) -> Token:
    user = authenticate_user(fake_users_db, form_data.username, form_data.password)
    if not user:
        raise HTTPException(status_code=400, detail="Incorrect username or password")
    access_token_expires = timedelta(minutes=ACCESS_TOKEN_EXPIRE_MINUTES)
    access_token = create_access_token(
        data={"sub": user.username, "scope": " ".join(form_data.scopes)},
        expires_delta=access_token_expires,
    )
    return Token(access_token=access_token, token_type="bearer")


@app.get("/users/me/", response_model=User)
async def read_users_me(
    current_user: Annotated[User, Depends(get_current_active_user)],
):
    return current_user


@app.get("/users/me/items/")
async def read_own_items(
    current_user: Annotated[User, Security(get_current_active_user, scopes=["items"])],
):
    return [{"item_id": "Foo", "owner": current_user.username}]


@app.get("/status/")
async def read_system_status(current_user: Annotated[User, Depends(get_current_user)]):
    return {"status": "ok"}

🤓 その他のバージョンとバリアント

Python 3.9+Python 3.8+Python 3.10+ - non-AnnotatedPython 3.9+ - 非注釈付きPython 3.8+ - non-Annotated

from datetime import datetime, timedelta, timezone
from typing import Annotated, Union

import jwt
from fastapi import Depends, FastAPI, HTTPException, Security, status
from fastapi.security import (
    OAuth2PasswordBearer,
    OAuth2PasswordRequestForm,
    SecurityScopes,
)
from jwt.exceptions import InvalidTokenError
from pwdlib import PasswordHash
from pydantic import BaseModel, ValidationError

# to get a string like this run:
# openssl rand -hex 32
SECRET_KEY = "09d25e094faa6ca2556c818166b7a9563b93f7099f6f0f4caa6cf63b88e8d3e7"
ALGORITHM = "HS256"
ACCESS_TOKEN_EXPIRE_MINUTES = 30


fake_users_db = {
    "johndoe": {
        "username": "johndoe",
        "full_name": "John Doe",
        "email": "johndoe@example.com",
        "hashed_password": "$argon2id$v=19$m=65536,t=3,p=4$wagCPXjifgvUFBzq4hqe3w$CYaIb8sB+wtD+Vu/P4uod1+Qof8h+1g7bbDlBID48Rc",
        "disabled": False,
    },
    "alice": {
        "username": "alice",
        "full_name": "Alice Chains",
        "email": "alicechains@example.com",
        "hashed_password": "$argon2id$v=19$m=65536,t=3,p=4$g2/AV1zwopqUntPKJavBFw$BwpRGDCyUHLvHICnwijyX8ROGoiUPwNKZ7915MeYfCE",
        "disabled": True,
    },
}


class Token(BaseModel):
    access_token: str
    token_type: str


class TokenData(BaseModel):
    username: Union[str, None] = None
    scopes: list[str] = []


class User(BaseModel):
    username: str
    email: Union[str, None] = None
    full_name: Union[str, None] = None
    disabled: Union[bool, None] = None


class UserInDB(User):
    hashed_password: str


password_hash = PasswordHash.recommended()

oauth2_scheme = OAuth2PasswordBearer(
    tokenUrl="token",
    scopes={"me": "Read information about the current user.", "items": "Read items."},
)

app = FastAPI()


def verify_password(plain_password, hashed_password):
    return password_hash.verify(plain_password, hashed_password)


def get_password_hash(password):
    return password_hash.hash(password)


def get_user(db, username: str):
    if username in db:
        user_dict = db[username]
        return UserInDB(**user_dict)


def authenticate_user(fake_db, username: str, password: str):
    user = get_user(fake_db, username)
    if not user:
        return False
    if not verify_password(password, user.hashed_password):
        return False
    return user


def create_access_token(data: dict, expires_delta: Union[timedelta, None] = None):
    to_encode = data.copy()
    if expires_delta:
        expire = datetime.now(timezone.utc) + expires_delta
    else:
        expire = datetime.now(timezone.utc) + timedelta(minutes=15)
    to_encode.update({"exp": expire})
    encoded_jwt = jwt.encode(to_encode, SECRET_KEY, algorithm=ALGORITHM)
    return encoded_jwt


async def get_current_user(
    security_scopes: SecurityScopes, token: Annotated[str, Depends(oauth2_scheme)]
):
    if security_scopes.scopes:
        authenticate_value = f'Bearer scope="{security_scopes.scope_str}"'
    else:
        authenticate_value = "Bearer"
    credentials_exception = HTTPException(
        status_code=status.HTTP_401_UNAUTHORIZED,
        detail="Could not validate credentials",
        headers={"WWW-Authenticate": authenticate_value},
    )
    try:
        payload = jwt.decode(token, SECRET_KEY, algorithms=[ALGORITHM])
        username = payload.get("sub")
        if username is None:
            raise credentials_exception
        scope: str = payload.get("scope", "")
        token_scopes = scope.split(" ")
        token_data = TokenData(scopes=token_scopes, username=username)
    except (InvalidTokenError, ValidationError):
        raise credentials_exception
    user = get_user(fake_users_db, username=token_data.username)
    if user is None:
        raise credentials_exception
    for scope in security_scopes.scopes:
        if scope not in token_data.scopes:
            raise HTTPException(
                status_code=status.HTTP_401_UNAUTHORIZED,
                detail="Not enough permissions",
                headers={"WWW-Authenticate": authenticate_value},
            )
    return user


async def get_current_active_user(
    current_user: Annotated[User, Security(get_current_user, scopes=["me"])],
):
    if current_user.disabled:
        raise HTTPException(status_code=400, detail="Inactive user")
    return current_user


@app.post("/token")
async def login_for_access_token(
    form_data: Annotated[OAuth2PasswordRequestForm, Depends()],
) -> Token:
    user = authenticate_user(fake_users_db, form_data.username, form_data.password)
    if not user:
        raise HTTPException(status_code=400, detail="Incorrect username or password")
    access_token_expires = timedelta(minutes=ACCESS_TOKEN_EXPIRE_MINUTES)
    access_token = create_access_token(
        data={"sub": user.username, "scope": " ".join(form_data.scopes)},
        expires_delta=access_token_expires,
    )
    return Token(access_token=access_token, token_type="bearer")


@app.get("/users/me/", response_model=User)
async def read_users_me(
    current_user: Annotated[User, Depends(get_current_active_user)],
):
    return current_user


@app.get("/users/me/items/")
async def read_own_items(
    current_user: Annotated[User, Security(get_current_active_user, scopes=["items"])],
):
    return [{"item_id": "Foo", "owner": current_user.username}]


@app.get("/status/")
async def read_system_status(current_user: Annotated[User, Depends(get_current_user)]):
    return {"status": "ok"}

from datetime import datetime, timedelta, timezone
from typing import List, Union

import jwt
from fastapi import Depends, FastAPI, HTTPException, Security, status
from fastapi.security import (
    OAuth2PasswordBearer,
    OAuth2PasswordRequestForm,
    SecurityScopes,
)
from jwt.exceptions import InvalidTokenError
from pwdlib import PasswordHash
from pydantic import BaseModel, ValidationError
from typing_extensions import Annotated

# to get a string like this run:
# openssl rand -hex 32
SECRET_KEY = "09d25e094faa6ca2556c818166b7a9563b93f7099f6f0f4caa6cf63b88e8d3e7"
ALGORITHM = "HS256"
ACCESS_TOKEN_EXPIRE_MINUTES = 30


fake_users_db = {
    "johndoe": {
        "username": "johndoe",
        "full_name": "John Doe",
        "email": "johndoe@example.com",
        "hashed_password": "$argon2id$v=19$m=65536,t=3,p=4$wagCPXjifgvUFBzq4hqe3w$CYaIb8sB+wtD+Vu/P4uod1+Qof8h+1g7bbDlBID48Rc",
        "disabled": False,
    },
    "alice": {
        "username": "alice",
        "full_name": "Alice Chains",
        "email": "alicechains@example.com",
        "hashed_password": "$argon2id$v=19$m=65536,t=3,p=4$g2/AV1zwopqUntPKJavBFw$BwpRGDCyUHLvHICnwijyX8ROGoiUPwNKZ7915MeYfCE",
        "disabled": True,
    },
}


class Token(BaseModel):
    access_token: str
    token_type: str


class TokenData(BaseModel):
    username: Union[str, None] = None
    scopes: List[str] = []


class User(BaseModel):
    username: str
    email: Union[str, None] = None
    full_name: Union[str, None] = None
    disabled: Union[bool, None] = None


class UserInDB(User):
    hashed_password: str


password_hash = PasswordHash.recommended()

oauth2_scheme = OAuth2PasswordBearer(
    tokenUrl="token",
    scopes={"me": "Read information about the current user.", "items": "Read items."},
)

app = FastAPI()


def verify_password(plain_password, hashed_password):
    return password_hash.verify(plain_password, hashed_password)


def get_password_hash(password):
    return password_hash.hash(password)


def get_user(db, username: str):
    if username in db:
        user_dict = db[username]
        return UserInDB(**user_dict)


def authenticate_user(fake_db, username: str, password: str):
    user = get_user(fake_db, username)
    if not user:
        return False
    if not verify_password(password, user.hashed_password):
        return False
    return user


def create_access_token(data: dict, expires_delta: Union[timedelta, None] = None):
    to_encode = data.copy()
    if expires_delta:
        expire = datetime.now(timezone.utc) + expires_delta
    else:
        expire = datetime.now(timezone.utc) + timedelta(minutes=15)
    to_encode.update({"exp": expire})
    encoded_jwt = jwt.encode(to_encode, SECRET_KEY, algorithm=ALGORITHM)
    return encoded_jwt


async def get_current_user(
    security_scopes: SecurityScopes, token: Annotated[str, Depends(oauth2_scheme)]
):
    if security_scopes.scopes:
        authenticate_value = f'Bearer scope="{security_scopes.scope_str}"'
    else:
        authenticate_value = "Bearer"
    credentials_exception = HTTPException(
        status_code=status.HTTP_401_UNAUTHORIZED,
        detail="Could not validate credentials",
        headers={"WWW-Authenticate": authenticate_value},
    )
    try:
        payload = jwt.decode(token, SECRET_KEY, algorithms=[ALGORITHM])
        username = payload.get("sub")
        if username is None:
            raise credentials_exception
        scope: str = payload.get("scope", "")
        token_scopes = scope.split(" ")
        token_data = TokenData(scopes=token_scopes, username=username)
    except (InvalidTokenError, ValidationError):
        raise credentials_exception
    user = get_user(fake_users_db, username=token_data.username)
    if user is None:
        raise credentials_exception
    for scope in security_scopes.scopes:
        if scope not in token_data.scopes:
            raise HTTPException(
                status_code=status.HTTP_401_UNAUTHORIZED,
                detail="Not enough permissions",
                headers={"WWW-Authenticate": authenticate_value},
            )
    return user


async def get_current_active_user(
    current_user: Annotated[User, Security(get_current_user, scopes=["me"])],
):
    if current_user.disabled:
        raise HTTPException(status_code=400, detail="Inactive user")
    return current_user


@app.post("/token")
async def login_for_access_token(
    form_data: Annotated[OAuth2PasswordRequestForm, Depends()],
) -> Token:
    user = authenticate_user(fake_users_db, form_data.username, form_data.password)
    if not user:
        raise HTTPException(status_code=400, detail="Incorrect username or password")
    access_token_expires = timedelta(minutes=ACCESS_TOKEN_EXPIRE_MINUTES)
    access_token = create_access_token(
        data={"sub": user.username, "scope": " ".join(form_data.scopes)},
        expires_delta=access_token_expires,
    )
    return Token(access_token=access_token, token_type="bearer")


@app.get("/users/me/", response_model=User)
async def read_users_me(
    current_user: Annotated[User, Depends(get_current_active_user)],
):
    return current_user


@app.get("/users/me/items/")
async def read_own_items(
    current_user: Annotated[User, Security(get_current_active_user, scopes=["items"])],
):
    return [{"item_id": "Foo", "owner": current_user.username}]


@app.get("/status/")
async def read_system_status(current_user: Annotated[User, Depends(get_current_user)]):
    return {"status": "ok"}

ヒント

可能であれば`Annotated`バージョンを使用することをお勧めします。

from datetime import datetime, timedelta, timezone

import jwt
from fastapi import Depends, FastAPI, HTTPException, Security, status
from fastapi.security import (
    OAuth2PasswordBearer,
    OAuth2PasswordRequestForm,
    SecurityScopes,
)
from jwt.exceptions import InvalidTokenError
from pwdlib import PasswordHash
from pydantic import BaseModel, ValidationError

# to get a string like this run:
# openssl rand -hex 32
SECRET_KEY = "09d25e094faa6ca2556c818166b7a9563b93f7099f6f0f4caa6cf63b88e8d3e7"
ALGORITHM = "HS256"
ACCESS_TOKEN_EXPIRE_MINUTES = 30


fake_users_db = {
    "johndoe": {
        "username": "johndoe",
        "full_name": "John Doe",
        "email": "johndoe@example.com",
        "hashed_password": "$argon2id$v=19$m=65536,t=3,p=4$wagCPXjifgvUFBzq4hqe3w$CYaIb8sB+wtD+Vu/P4uod1+Qof8h+1g7bbDlBID48Rc",
        "disabled": False,
    },
    "alice": {
        "username": "alice",
        "full_name": "Alice Chains",
        "email": "alicechains@example.com",
        "hashed_password": "$argon2id$v=19$m=65536,t=3,p=4$g2/AV1zwopqUntPKJavBFw$BwpRGDCyUHLvHICnwijyX8ROGoiUPwNKZ7915MeYfCE",
        "disabled": True,
    },
}


class Token(BaseModel):
    access_token: str
    token_type: str


class TokenData(BaseModel):
    username: str | None = None
    scopes: list[str] = []


class User(BaseModel):
    username: str
    email: str | None = None
    full_name: str | None = None
    disabled: bool | None = None


class UserInDB(User):
    hashed_password: str


password_hash = PasswordHash.recommended()

oauth2_scheme = OAuth2PasswordBearer(
    tokenUrl="token",
    scopes={"me": "Read information about the current user.", "items": "Read items."},
)

app = FastAPI()


def verify_password(plain_password, hashed_password):
    return password_hash.verify(plain_password, hashed_password)


def get_password_hash(password):
    return password_hash.hash(password)


def get_user(db, username: str):
    if username in db:
        user_dict = db[username]
        return UserInDB(**user_dict)


def authenticate_user(fake_db, username: str, password: str):
    user = get_user(fake_db, username)
    if not user:
        return False
    if not verify_password(password, user.hashed_password):
        return False
    return user


def create_access_token(data: dict, expires_delta: timedelta | None = None):
    to_encode = data.copy()
    if expires_delta:
        expire = datetime.now(timezone.utc) + expires_delta
    else:
        expire = datetime.now(timezone.utc) + timedelta(minutes=15)
    to_encode.update({"exp": expire})
    encoded_jwt = jwt.encode(to_encode, SECRET_KEY, algorithm=ALGORITHM)
    return encoded_jwt


async def get_current_user(
    security_scopes: SecurityScopes, token: str = Depends(oauth2_scheme)
):
    if security_scopes.scopes:
        authenticate_value = f'Bearer scope="{security_scopes.scope_str}"'
    else:
        authenticate_value = "Bearer"
    credentials_exception = HTTPException(
        status_code=status.HTTP_401_UNAUTHORIZED,
        detail="Could not validate credentials",
        headers={"WWW-Authenticate": authenticate_value},
    )
    try:
        payload = jwt.decode(token, SECRET_KEY, algorithms=[ALGORITHM])
        username: str = payload.get("sub")
        if username is None:
            raise credentials_exception
        scope: str = payload.get("scope", "")
        token_scopes = scope.split(" ")
        token_data = TokenData(scopes=token_scopes, username=username)
    except (InvalidTokenError, ValidationError):
        raise credentials_exception
    user = get_user(fake_users_db, username=token_data.username)
    if user is None:
        raise credentials_exception
    for scope in security_scopes.scopes:
        if scope not in token_data.scopes:
            raise HTTPException(
                status_code=status.HTTP_401_UNAUTHORIZED,
                detail="Not enough permissions",
                headers={"WWW-Authenticate": authenticate_value},
            )
    return user


async def get_current_active_user(
    current_user: User = Security(get_current_user, scopes=["me"]),
):
    if current_user.disabled:
        raise HTTPException(status_code=400, detail="Inactive user")
    return current_user


@app.post("/token")
async def login_for_access_token(
    form_data: OAuth2PasswordRequestForm = Depends(),
) -> Token:
    user = authenticate_user(fake_users_db, form_data.username, form_data.password)
    if not user:
        raise HTTPException(status_code=400, detail="Incorrect username or password")
    access_token_expires = timedelta(minutes=ACCESS_TOKEN_EXPIRE_MINUTES)
    access_token = create_access_token(
        data={"sub": user.username, "scope": " ".join(form_data.scopes)},
        expires_delta=access_token_expires,
    )
    return Token(access_token=access_token, token_type="bearer")


@app.get("/users/me/", response_model=User)
async def read_users_me(current_user: User = Depends(get_current_active_user)):
    return current_user


@app.get("/users/me/items/")
async def read_own_items(
    current_user: User = Security(get_current_active_user, scopes=["items"]),
):
    return [{"item_id": "Foo", "owner": current_user.username}]


@app.get("/status/")
async def read_system_status(current_user: User = Depends(get_current_user)):
    return {"status": "ok"}

ヒント

可能であれば`Annotated`バージョンを使用することをお勧めします。

from datetime import datetime, timedelta, timezone
from typing import Union

import jwt
from fastapi import Depends, FastAPI, HTTPException, Security, status
from fastapi.security import (
    OAuth2PasswordBearer,
    OAuth2PasswordRequestForm,
    SecurityScopes,
)
from jwt.exceptions import InvalidTokenError
from pwdlib import PasswordHash
from pydantic import BaseModel, ValidationError

# to get a string like this run:
# openssl rand -hex 32
SECRET_KEY = "09d25e094faa6ca2556c818166b7a9563b93f7099f6f0f4caa6cf63b88e8d3e7"
ALGORITHM = "HS256"
ACCESS_TOKEN_EXPIRE_MINUTES = 30


fake_users_db = {
    "johndoe": {
        "username": "johndoe",
        "full_name": "John Doe",
        "email": "johndoe@example.com",
        "hashed_password": "$argon2id$v=19$m=65536,t=3,p=4$wagCPXjifgvUFBzq4hqe3w$CYaIb8sB+wtD+Vu/P4uod1+Qof8h+1g7bbDlBID48Rc",
        "disabled": False,
    },
    "alice": {
        "username": "alice",
        "full_name": "Alice Chains",
        "email": "alicechains@example.com",
        "hashed_password": "$argon2id$v=19$m=65536,t=3,p=4$g2/AV1zwopqUntPKJavBFw$BwpRGDCyUHLvHICnwijyX8ROGoiUPwNKZ7915MeYfCE",
        "disabled": True,
    },
}


class Token(BaseModel):
    access_token: str
    token_type: str


class TokenData(BaseModel):
    username: Union[str, None] = None
    scopes: list[str] = []


class User(BaseModel):
    username: str
    email: Union[str, None] = None
    full_name: Union[str, None] = None
    disabled: Union[bool, None] = None


class UserInDB(User):
    hashed_password: str


password_hash = PasswordHash.recommended()

oauth2_scheme = OAuth2PasswordBearer(
    tokenUrl="token",
    scopes={"me": "Read information about the current user.", "items": "Read items."},
)

app = FastAPI()


def verify_password(plain_password, hashed_password):
    return password_hash.verify(plain_password, hashed_password)


def get_password_hash(password):
    return password_hash.hash(password)


def get_user(db, username: str):
    if username in db:
        user_dict = db[username]
        return UserInDB(**user_dict)


def authenticate_user(fake_db, username: str, password: str):
    user = get_user(fake_db, username)
    if not user:
        return False
    if not verify_password(password, user.hashed_password):
        return False
    return user


def create_access_token(data: dict, expires_delta: Union[timedelta, None] = None):
    to_encode = data.copy()
    if expires_delta:
        expire = datetime.now(timezone.utc) + expires_delta
    else:
        expire = datetime.now(timezone.utc) + timedelta(minutes=15)
    to_encode.update({"exp": expire})
    encoded_jwt = jwt.encode(to_encode, SECRET_KEY, algorithm=ALGORITHM)
    return encoded_jwt


async def get_current_user(
    security_scopes: SecurityScopes, token: str = Depends(oauth2_scheme)
):
    if security_scopes.scopes:
        authenticate_value = f'Bearer scope="{security_scopes.scope_str}"'
    else:
        authenticate_value = "Bearer"
    credentials_exception = HTTPException(
        status_code=status.HTTP_401_UNAUTHORIZED,
        detail="Could not validate credentials",
        headers={"WWW-Authenticate": authenticate_value},
    )
    try:
        payload = jwt.decode(token, SECRET_KEY, algorithms=[ALGORITHM])
        username: str = payload.get("sub")
        if username is None:
            raise credentials_exception
        scope: str = payload.get("scope", "")
        token_scopes = scope.split(" ")
        token_data = TokenData(scopes=token_scopes, username=username)
    except (InvalidTokenError, ValidationError):
        raise credentials_exception
    user = get_user(fake_users_db, username=token_data.username)
    if user is None:
        raise credentials_exception
    for scope in security_scopes.scopes:
        if scope not in token_data.scopes:
            raise HTTPException(
                status_code=status.HTTP_401_UNAUTHORIZED,
                detail="Not enough permissions",
                headers={"WWW-Authenticate": authenticate_value},
            )
    return user


async def get_current_active_user(
    current_user: User = Security(get_current_user, scopes=["me"]),
):
    if current_user.disabled:
        raise HTTPException(status_code=400, detail="Inactive user")
    return current_user


@app.post("/token")
async def login_for_access_token(
    form_data: OAuth2PasswordRequestForm = Depends(),
) -> Token:
    user = authenticate_user(fake_users_db, form_data.username, form_data.password)
    if not user:
        raise HTTPException(status_code=400, detail="Incorrect username or password")
    access_token_expires = timedelta(minutes=ACCESS_TOKEN_EXPIRE_MINUTES)
    access_token = create_access_token(
        data={"sub": user.username, "scope": " ".join(form_data.scopes)},
        expires_delta=access_token_expires,
    )
    return Token(access_token=access_token, token_type="bearer")


@app.get("/users/me/", response_model=User)
async def read_users_me(current_user: User = Depends(get_current_active_user)):
    return current_user


@app.get("/users/me/items/")
async def read_own_items(
    current_user: User = Security(get_current_active_user, scopes=["items"]),
):
    return [{"item_id": "Foo", "owner": current_user.username}]


@app.get("/status/")
async def read_system_status(current_user: User = Depends(get_current_user)):
    return {"status": "ok"}

ヒント

可能であれば`Annotated`バージョンを使用することをお勧めします。

from datetime import datetime, timedelta, timezone
from typing import List, Union

import jwt
from fastapi import Depends, FastAPI, HTTPException, Security, status
from fastapi.security import (
    OAuth2PasswordBearer,
    OAuth2PasswordRequestForm,
    SecurityScopes,
)
from jwt.exceptions import InvalidTokenError
from pwdlib import PasswordHash
from pydantic import BaseModel, ValidationError

# to get a string like this run:
# openssl rand -hex 32
SECRET_KEY = "09d25e094faa6ca2556c818166b7a9563b93f7099f6f0f4caa6cf63b88e8d3e7"
ALGORITHM = "HS256"
ACCESS_TOKEN_EXPIRE_MINUTES = 30


fake_users_db = {
    "johndoe": {
        "username": "johndoe",
        "full_name": "John Doe",
        "email": "johndoe@example.com",
        "hashed_password": "$argon2id$v=19$m=65536,t=3,p=4$wagCPXjifgvUFBzq4hqe3w$CYaIb8sB+wtD+Vu/P4uod1+Qof8h+1g7bbDlBID48Rc",
        "disabled": False,
    },
    "alice": {
        "username": "alice",
        "full_name": "Alice Chains",
        "email": "alicechains@example.com",
        "hashed_password": "$argon2id$v=19$m=65536,t=3,p=4$g2/AV1zwopqUntPKJavBFw$BwpRGDCyUHLvHICnwijyX8ROGoiUPwNKZ7915MeYfCE",
        "disabled": True,
    },
}


class Token(BaseModel):
    access_token: str
    token_type: str


class TokenData(BaseModel):
    username: Union[str, None] = None
    scopes: List[str] = []


class User(BaseModel):
    username: str
    email: Union[str, None] = None
    full_name: Union[str, None] = None
    disabled: Union[bool, None] = None


class UserInDB(User):
    hashed_password: str


password_hash = PasswordHash.recommended()

oauth2_scheme = OAuth2PasswordBearer(
    tokenUrl="token",
    scopes={"me": "Read information about the current user.", "items": "Read items."},
)

app = FastAPI()


def verify_password(plain_password, hashed_password):
    return password_hash.verify(plain_password, hashed_password)


def get_password_hash(password):
    return password_hash.hash(password)


def get_user(db, username: str):
    if username in db:
        user_dict = db[username]
        return UserInDB(**user_dict)


def authenticate_user(fake_db, username: str, password: str):
    user = get_user(fake_db, username)
    if not user:
        return False
    if not verify_password(password, user.hashed_password):
        return False
    return user


def create_access_token(data: dict, expires_delta: Union[timedelta, None] = None):
    to_encode = data.copy()
    if expires_delta:
        expire = datetime.now(timezone.utc) + expires_delta
    else:
        expire = datetime.now(timezone.utc) + timedelta(minutes=15)
    to_encode.update({"exp": expire})
    encoded_jwt = jwt.encode(to_encode, SECRET_KEY, algorithm=ALGORITHM)
    return encoded_jwt


async def get_current_user(
    security_scopes: SecurityScopes, token: str = Depends(oauth2_scheme)
):
    if security_scopes.scopes:
        authenticate_value = f'Bearer scope="{security_scopes.scope_str}"'
    else:
        authenticate_value = "Bearer"
    credentials_exception = HTTPException(
        status_code=status.HTTP_401_UNAUTHORIZED,
        detail="Could not validate credentials",
        headers={"WWW-Authenticate": authenticate_value},
    )
    try:
        payload = jwt.decode(token, SECRET_KEY, algorithms=[ALGORITHM])
        username: str = payload.get("sub")
        if username is None:
            raise credentials_exception
        scope: str = payload.get("scope", "")
        token_scopes = scope.split(" ")
        token_data = TokenData(scopes=token_scopes, username=username)
    except (InvalidTokenError, ValidationError):
        raise credentials_exception
    user = get_user(fake_users_db, username=token_data.username)
    if user is None:
        raise credentials_exception
    for scope in security_scopes.scopes:
        if scope not in token_data.scopes:
            raise HTTPException(
                status_code=status.HTTP_401_UNAUTHORIZED,
                detail="Not enough permissions",
                headers={"WWW-Authenticate": authenticate_value},
            )
    return user


async def get_current_active_user(
    current_user: User = Security(get_current_user, scopes=["me"]),
):
    if current_user.disabled:
        raise HTTPException(status_code=400, detail="Inactive user")
    return current_user


@app.post("/token")
async def login_for_access_token(
    form_data: OAuth2PasswordRequestForm = Depends(),
) -> Token:
    user = authenticate_user(fake_users_db, form_data.username, form_data.password)
    if not user:
        raise HTTPException(status_code=400, detail="Incorrect username or password")
    access_token_expires = timedelta(minutes=ACCESS_TOKEN_EXPIRE_MINUTES)
    access_token = create_access_token(
        data={"sub": user.username, "scope": " ".join(form_data.scopes)},
        expires_delta=access_token_expires,
    )
    return Token(access_token=access_token, token_type="bearer")


@app.get("/users/me/", response_model=User)
async def read_users_me(current_user: User = Depends(get_current_active_user)):
    return current_user


@app.get("/users/me/items/")
async def read_own_items(
    current_user: User = Security(get_current_active_user, scopes=["items"]),
):
    return [{"item_id": "Foo", "owner": current_user.username}]


@app.get("/status/")
async def read_system_status(current_user: User = Depends(get_current_user)):
    return {"status": "ok"}

scopesを使用する

パラメータsecurity_scopesはSecurityScopes型になります。

これには、自身と、これをサブ依存関係として使用するすべての依存関係によって要求されるすべてのスコープを含むリストを持つscopesプロパティがあります。つまり、すべての「依存者」です...これは紛らわしく聞こえるかもしれませんが、後で詳しく説明します。

security_scopesオブジェクト（SecurityScopesクラス）は、これらのスコープをスペースで区切った単一の文字列を含むscope_str属性も提供します（これを使用します）。

後でいくつかの場所で再利用（raise）できるHTTPExceptionを作成します。

この例外には、必要なスコープ（もしあれば）をスペースで区切られた文字列（scope_strを使用）として含めます。スコープを含むその文字列をWWW-Authenticateヘッダーに入れます（これは仕様の一部です）。

Python 3.10+

from datetime import datetime, timedelta, timezone
from typing import Annotated

import jwt
from fastapi import Depends, FastAPI, HTTPException, Security, status
from fastapi.security import (
    OAuth2PasswordBearer,
    OAuth2PasswordRequestForm,
    SecurityScopes,
)
from jwt.exceptions import InvalidTokenError
from pwdlib import PasswordHash
from pydantic import BaseModel, ValidationError

# to get a string like this run:
# openssl rand -hex 32
SECRET_KEY = "09d25e094faa6ca2556c818166b7a9563b93f7099f6f0f4caa6cf63b88e8d3e7"
ALGORITHM = "HS256"
ACCESS_TOKEN_EXPIRE_MINUTES = 30


fake_users_db = {
    "johndoe": {
        "username": "johndoe",
        "full_name": "John Doe",
        "email": "johndoe@example.com",
        "hashed_password": "$argon2id$v=19$m=65536,t=3,p=4$wagCPXjifgvUFBzq4hqe3w$CYaIb8sB+wtD+Vu/P4uod1+Qof8h+1g7bbDlBID48Rc",
        "disabled": False,
    },
    "alice": {
        "username": "alice",
        "full_name": "Alice Chains",
        "email": "alicechains@example.com",
        "hashed_password": "$argon2id$v=19$m=65536,t=3,p=4$g2/AV1zwopqUntPKJavBFw$BwpRGDCyUHLvHICnwijyX8ROGoiUPwNKZ7915MeYfCE",
        "disabled": True,
    },
}


class Token(BaseModel):
    access_token: str
    token_type: str


class TokenData(BaseModel):
    username: str | None = None
    scopes: list[str] = []


class User(BaseModel):
    username: str
    email: str | None = None
    full_name: str | None = None
    disabled: bool | None = None


class UserInDB(User):
    hashed_password: str


password_hash = PasswordHash.recommended()

oauth2_scheme = OAuth2PasswordBearer(
    tokenUrl="token",
    scopes={"me": "Read information about the current user.", "items": "Read items."},
)

app = FastAPI()


def verify_password(plain_password, hashed_password):
    return password_hash.verify(plain_password, hashed_password)


def get_password_hash(password):
    return password_hash.hash(password)


def get_user(db, username: str):
    if username in db:
        user_dict = db[username]
        return UserInDB(**user_dict)


def authenticate_user(fake_db, username: str, password: str):
    user = get_user(fake_db, username)
    if not user:
        return False
    if not verify_password(password, user.hashed_password):
        return False
    return user


def create_access_token(data: dict, expires_delta: timedelta | None = None):
    to_encode = data.copy()
    if expires_delta:
        expire = datetime.now(timezone.utc) + expires_delta
    else:
        expire = datetime.now(timezone.utc) + timedelta(minutes=15)
    to_encode.update({"exp": expire})
    encoded_jwt = jwt.encode(to_encode, SECRET_KEY, algorithm=ALGORITHM)
    return encoded_jwt


async def get_current_user(
    security_scopes: SecurityScopes, token: Annotated[str, Depends(oauth2_scheme)]
):
    if security_scopes.scopes:
        authenticate_value = f'Bearer scope="{security_scopes.scope_str}"'
    else:
        authenticate_value = "Bearer"
    credentials_exception = HTTPException(
        status_code=status.HTTP_401_UNAUTHORIZED,
        detail="Could not validate credentials",
        headers={"WWW-Authenticate": authenticate_value},
    )
    try:
        payload = jwt.decode(token, SECRET_KEY, algorithms=[ALGORITHM])
        username = payload.get("sub")
        if username is None:
            raise credentials_exception
        scope: str = payload.get("scope", "")
        token_scopes = scope.split(" ")
        token_data = TokenData(scopes=token_scopes, username=username)
    except (InvalidTokenError, ValidationError):
        raise credentials_exception
    user = get_user(fake_users_db, username=token_data.username)
    if user is None:
        raise credentials_exception
    for scope in security_scopes.scopes:
        if scope not in token_data.scopes:
            raise HTTPException(
                status_code=status.HTTP_401_UNAUTHORIZED,
                detail="Not enough permissions",
                headers={"WWW-Authenticate": authenticate_value},
            )
    return user


async def get_current_active_user(
    current_user: Annotated[User, Security(get_current_user, scopes=["me"])],
):
    if current_user.disabled:
        raise HTTPException(status_code=400, detail="Inactive user")
    return current_user


@app.post("/token")
async def login_for_access_token(
    form_data: Annotated[OAuth2PasswordRequestForm, Depends()],
) -> Token:
    user = authenticate_user(fake_users_db, form_data.username, form_data.password)
    if not user:
        raise HTTPException(status_code=400, detail="Incorrect username or password")
    access_token_expires = timedelta(minutes=ACCESS_TOKEN_EXPIRE_MINUTES)
    access_token = create_access_token(
        data={"sub": user.username, "scope": " ".join(form_data.scopes)},
        expires_delta=access_token_expires,
    )
    return Token(access_token=access_token, token_type="bearer")


@app.get("/users/me/", response_model=User)
async def read_users_me(
    current_user: Annotated[User, Depends(get_current_active_user)],
):
    return current_user


@app.get("/users/me/items/")
async def read_own_items(
    current_user: Annotated[User, Security(get_current_active_user, scopes=["items"])],
):
    return [{"item_id": "Foo", "owner": current_user.username}]


@app.get("/status/")
async def read_system_status(current_user: Annotated[User, Depends(get_current_user)]):
    return {"status": "ok"}

🤓 その他のバージョンとバリアント

Python 3.9+Python 3.8+Python 3.10+ - non-AnnotatedPython 3.9+ - 非注釈付きPython 3.8+ - non-Annotated

from datetime import datetime, timedelta, timezone
from typing import Annotated, Union

import jwt
from fastapi import Depends, FastAPI, HTTPException, Security, status
from fastapi.security import (
    OAuth2PasswordBearer,
    OAuth2PasswordRequestForm,
    SecurityScopes,
)
from jwt.exceptions import InvalidTokenError
from pwdlib import PasswordHash
from pydantic import BaseModel, ValidationError

# to get a string like this run:
# openssl rand -hex 32
SECRET_KEY = "09d25e094faa6ca2556c818166b7a9563b93f7099f6f0f4caa6cf63b88e8d3e7"
ALGORITHM = "HS256"
ACCESS_TOKEN_EXPIRE_MINUTES = 30


fake_users_db = {
    "johndoe": {
        "username": "johndoe",
        "full_name": "John Doe",
        "email": "johndoe@example.com",
        "hashed_password": "$argon2id$v=19$m=65536,t=3,p=4$wagCPXjifgvUFBzq4hqe3w$CYaIb8sB+wtD+Vu/P4uod1+Qof8h+1g7bbDlBID48Rc",
        "disabled": False,
    },
    "alice": {
        "username": "alice",
        "full_name": "Alice Chains",
        "email": "alicechains@example.com",
        "hashed_password": "$argon2id$v=19$m=65536,t=3,p=4$g2/AV1zwopqUntPKJavBFw$BwpRGDCyUHLvHICnwijyX8ROGoiUPwNKZ7915MeYfCE",
        "disabled": True,
    },
}


class Token(BaseModel):
    access_token: str
    token_type: str


class TokenData(BaseModel):
    username: Union[str, None] = None
    scopes: list[str] = []


class User(BaseModel):
    username: str
    email: Union[str, None] = None
    full_name: Union[str, None] = None
    disabled: Union[bool, None] = None


class UserInDB(User):
    hashed_password: str


password_hash = PasswordHash.recommended()

oauth2_scheme = OAuth2PasswordBearer(
    tokenUrl="token",
    scopes={"me": "Read information about the current user.", "items": "Read items."},
)

app = FastAPI()


def verify_password(plain_password, hashed_password):
    return password_hash.verify(plain_password, hashed_password)


def get_password_hash(password):
    return password_hash.hash(password)


def get_user(db, username: str):
    if username in db:
        user_dict = db[username]
        return UserInDB(**user_dict)


def authenticate_user(fake_db, username: str, password: str):
    user = get_user(fake_db, username)
    if not user:
        return False
    if not verify_password(password, user.hashed_password):
        return False
    return user


def create_access_token(data: dict, expires_delta: Union[timedelta, None] = None):
    to_encode = data.copy()
    if expires_delta:
        expire = datetime.now(timezone.utc) + expires_delta
    else:
        expire = datetime.now(timezone.utc) + timedelta(minutes=15)
    to_encode.update({"exp": expire})
    encoded_jwt = jwt.encode(to_encode, SECRET_KEY, algorithm=ALGORITHM)
    return encoded_jwt


async def get_current_user(
    security_scopes: SecurityScopes, token: Annotated[str, Depends(oauth2_scheme)]
):
    if security_scopes.scopes:
        authenticate_value = f'Bearer scope="{security_scopes.scope_str}"'
    else:
        authenticate_value = "Bearer"
    credentials_exception = HTTPException(
        status_code=status.HTTP_401_UNAUTHORIZED,
        detail="Could not validate credentials",
        headers={"WWW-Authenticate": authenticate_value},
    )
    try:
        payload = jwt.decode(token, SECRET_KEY, algorithms=[ALGORITHM])
        username = payload.get("sub")
        if username is None:
            raise credentials_exception
        scope: str = payload.get("scope", "")
        token_scopes = scope.split(" ")
        token_data = TokenData(scopes=token_scopes, username=username)
    except (InvalidTokenError, ValidationError):
        raise credentials_exception
    user = get_user(fake_users_db, username=token_data.username)
    if user is None:
        raise credentials_exception
    for scope in security_scopes.scopes:
        if scope not in token_data.scopes:
            raise HTTPException(
                status_code=status.HTTP_401_UNAUTHORIZED,
                detail="Not enough permissions",
                headers={"WWW-Authenticate": authenticate_value},
            )
    return user


async def get_current_active_user(
    current_user: Annotated[User, Security(get_current_user, scopes=["me"])],
):
    if current_user.disabled:
        raise HTTPException(status_code=400, detail="Inactive user")
    return current_user


@app.post("/token")
async def login_for_access_token(
    form_data: Annotated[OAuth2PasswordRequestForm, Depends()],
) -> Token:
    user = authenticate_user(fake_users_db, form_data.username, form_data.password)
    if not user:
        raise HTTPException(status_code=400, detail="Incorrect username or password")
    access_token_expires = timedelta(minutes=ACCESS_TOKEN_EXPIRE_MINUTES)
    access_token = create_access_token(
        data={"sub": user.username, "scope": " ".join(form_data.scopes)},
        expires_delta=access_token_expires,
    )
    return Token(access_token=access_token, token_type="bearer")


@app.get("/users/me/", response_model=User)
async def read_users_me(
    current_user: Annotated[User, Depends(get_current_active_user)],
):
    return current_user


@app.get("/users/me/items/")
async def read_own_items(
    current_user: Annotated[User, Security(get_current_active_user, scopes=["items"])],
):
    return [{"item_id": "Foo", "owner": current_user.username}]


@app.get("/status/")
async def read_system_status(current_user: Annotated[User, Depends(get_current_user)]):
    return {"status": "ok"}

from datetime import datetime, timedelta, timezone
from typing import List, Union

import jwt
from fastapi import Depends, FastAPI, HTTPException, Security, status
from fastapi.security import (
    OAuth2PasswordBearer,
    OAuth2PasswordRequestForm,
    SecurityScopes,
)
from jwt.exceptions import InvalidTokenError
from pwdlib import PasswordHash
from pydantic import BaseModel, ValidationError
from typing_extensions import Annotated

# to get a string like this run:
# openssl rand -hex 32
SECRET_KEY = "09d25e094faa6ca2556c818166b7a9563b93f7099f6f0f4caa6cf63b88e8d3e7"
ALGORITHM = "HS256"
ACCESS_TOKEN_EXPIRE_MINUTES = 30


fake_users_db = {
    "johndoe": {
        "username": "johndoe",
        "full_name": "John Doe",
        "email": "johndoe@example.com",
        "hashed_password": "$argon2id$v=19$m=65536,t=3,p=4$wagCPXjifgvUFBzq4hqe3w$CYaIb8sB+wtD+Vu/P4uod1+Qof8h+1g7bbDlBID48Rc",
        "disabled": False,
    },
    "alice": {
        "username": "alice",
        "full_name": "Alice Chains",
        "email": "alicechains@example.com",
        "hashed_password": "$argon2id$v=19$m=65536,t=3,p=4$g2/AV1zwopqUntPKJavBFw$BwpRGDCyUHLvHICnwijyX8ROGoiUPwNKZ7915MeYfCE",
        "disabled": True,
    },
}


class Token(BaseModel):
    access_token: str
    token_type: str


class TokenData(BaseModel):
    username: Union[str, None] = None
    scopes: List[str] = []


class User(BaseModel):
    username: str
    email: Union[str, None] = None
    full_name: Union[str, None] = None
    disabled: Union[bool, None] = None


class UserInDB(User):
    hashed_password: str


password_hash = PasswordHash.recommended()

oauth2_scheme = OAuth2PasswordBearer(
    tokenUrl="token",
    scopes={"me": "Read information about the current user.", "items": "Read items."},
)

app = FastAPI()


def verify_password(plain_password, hashed_password):
    return password_hash.verify(plain_password, hashed_password)


def get_password_hash(password):
    return password_hash.hash(password)


def get_user(db, username: str):
    if username in db:
        user_dict = db[username]
        return UserInDB(**user_dict)


def authenticate_user(fake_db, username: str, password: str):
    user = get_user(fake_db, username)
    if not user:
        return False
    if not verify_password(password, user.hashed_password):
        return False
    return user


def create_access_token(data: dict, expires_delta: Union[timedelta, None] = None):
    to_encode = data.copy()
    if expires_delta:
        expire = datetime.now(timezone.utc) + expires_delta
    else:
        expire = datetime.now(timezone.utc) + timedelta(minutes=15)
    to_encode.update({"exp": expire})
    encoded_jwt = jwt.encode(to_encode, SECRET_KEY, algorithm=ALGORITHM)
    return encoded_jwt


async def get_current_user(
    security_scopes: SecurityScopes, token: Annotated[str, Depends(oauth2_scheme)]
):
    if security_scopes.scopes:
        authenticate_value = f'Bearer scope="{security_scopes.scope_str}"'
    else:
        authenticate_value = "Bearer"
    credentials_exception = HTTPException(
        status_code=status.HTTP_401_UNAUTHORIZED,
        detail="Could not validate credentials",
        headers={"WWW-Authenticate": authenticate_value},
    )
    try:
        payload = jwt.decode(token, SECRET_KEY, algorithms=[ALGORITHM])
        username = payload.get("sub")
        if username is None:
            raise credentials_exception
        scope: str = payload.get("scope", "")
        token_scopes = scope.split(" ")
        token_data = TokenData(scopes=token_scopes, username=username)
    except (InvalidTokenError, ValidationError):
        raise credentials_exception
    user = get_user(fake_users_db, username=token_data.username)
    if user is None:
        raise credentials_exception
    for scope in security_scopes.scopes:
        if scope not in token_data.scopes:
            raise HTTPException(
                status_code=status.HTTP_401_UNAUTHORIZED,
                detail="Not enough permissions",
                headers={"WWW-Authenticate": authenticate_value},
            )
    return user


async def get_current_active_user(
    current_user: Annotated[User, Security(get_current_user, scopes=["me"])],
):
    if current_user.disabled:
        raise HTTPException(status_code=400, detail="Inactive user")
    return current_user


@app.post("/token")
async def login_for_access_token(
    form_data: Annotated[OAuth2PasswordRequestForm, Depends()],
) -> Token:
    user = authenticate_user(fake_users_db, form_data.username, form_data.password)
    if not user:
        raise HTTPException(status_code=400, detail="Incorrect username or password")
    access_token_expires = timedelta(minutes=ACCESS_TOKEN_EXPIRE_MINUTES)
    access_token = create_access_token(
        data={"sub": user.username, "scope": " ".join(form_data.scopes)},
        expires_delta=access_token_expires,
    )
    return Token(access_token=access_token, token_type="bearer")


@app.get("/users/me/", response_model=User)
async def read_users_me(
    current_user: Annotated[User, Depends(get_current_active_user)],
):
    return current_user


@app.get("/users/me/items/")
async def read_own_items(
    current_user: Annotated[User, Security(get_current_active_user, scopes=["items"])],
):
    return [{"item_id": "Foo", "owner": current_user.username}]


@app.get("/status/")
async def read_system_status(current_user: Annotated[User, Depends(get_current_user)]):
    return {"status": "ok"}

ヒント

可能であれば`Annotated`バージョンを使用することをお勧めします。

from datetime import datetime, timedelta, timezone

import jwt
from fastapi import Depends, FastAPI, HTTPException, Security, status
from fastapi.security import (
    OAuth2PasswordBearer,
    OAuth2PasswordRequestForm,
    SecurityScopes,
)
from jwt.exceptions import InvalidTokenError
from pwdlib import PasswordHash
from pydantic import BaseModel, ValidationError

# to get a string like this run:
# openssl rand -hex 32
SECRET_KEY = "09d25e094faa6ca2556c818166b7a9563b93f7099f6f0f4caa6cf63b88e8d3e7"
ALGORITHM = "HS256"
ACCESS_TOKEN_EXPIRE_MINUTES = 30


fake_users_db = {
    "johndoe": {
        "username": "johndoe",
        "full_name": "John Doe",
        "email": "johndoe@example.com",
        "hashed_password": "$argon2id$v=19$m=65536,t=3,p=4$wagCPXjifgvUFBzq4hqe3w$CYaIb8sB+wtD+Vu/P4uod1+Qof8h+1g7bbDlBID48Rc",
        "disabled": False,
    },
    "alice": {
        "username": "alice",
        "full_name": "Alice Chains",
        "email": "alicechains@example.com",
        "hashed_password": "$argon2id$v=19$m=65536,t=3,p=4$g2/AV1zwopqUntPKJavBFw$BwpRGDCyUHLvHICnwijyX8ROGoiUPwNKZ7915MeYfCE",
        "disabled": True,
    },
}


class Token(BaseModel):
    access_token: str
    token_type: str


class TokenData(BaseModel):
    username: str | None = None
    scopes: list[str] = []


class User(BaseModel):
    username: str
    email: str | None = None
    full_name: str | None = None
    disabled: bool | None = None


class UserInDB(User):
    hashed_password: str


password_hash = PasswordHash.recommended()

oauth2_scheme = OAuth2PasswordBearer(
    tokenUrl="token",
    scopes={"me": "Read information about the current user.", "items": "Read items."},
)

app = FastAPI()


def verify_password(plain_password, hashed_password):
    return password_hash.verify(plain_password, hashed_password)


def get_password_hash(password):
    return password_hash.hash(password)


def get_user(db, username: str):
    if username in db:
        user_dict = db[username]
        return UserInDB(**user_dict)


def authenticate_user(fake_db, username: str, password: str):
    user = get_user(fake_db, username)
    if not user:
        return False
    if not verify_password(password, user.hashed_password):
        return False
    return user


def create_access_token(data: dict, expires_delta: timedelta | None = None):
    to_encode = data.copy()
    if expires_delta:
        expire = datetime.now(timezone.utc) + expires_delta
    else:
        expire = datetime.now(timezone.utc) + timedelta(minutes=15)
    to_encode.update({"exp": expire})
    encoded_jwt = jwt.encode(to_encode, SECRET_KEY, algorithm=ALGORITHM)
    return encoded_jwt


async def get_current_user(
    security_scopes: SecurityScopes, token: str = Depends(oauth2_scheme)
):
    if security_scopes.scopes:
        authenticate_value = f'Bearer scope="{security_scopes.scope_str}"'
    else:
        authenticate_value = "Bearer"
    credentials_exception = HTTPException(
        status_code=status.HTTP_401_UNAUTHORIZED,
        detail="Could not validate credentials",
        headers={"WWW-Authenticate": authenticate_value},
    )
    try:
        payload = jwt.decode(token, SECRET_KEY, algorithms=[ALGORITHM])
        username: str = payload.get("sub")
        if username is None:
            raise credentials_exception
        scope: str = payload.get("scope", "")
        token_scopes = scope.split(" ")
        token_data = TokenData(scopes=token_scopes, username=username)
    except (InvalidTokenError, ValidationError):
        raise credentials_exception
    user = get_user(fake_users_db, username=token_data.username)
    if user is None:
        raise credentials_exception
    for scope in security_scopes.scopes:
        if scope not in token_data.scopes:
            raise HTTPException(
                status_code=status.HTTP_401_UNAUTHORIZED,
                detail="Not enough permissions",
                headers={"WWW-Authenticate": authenticate_value},
            )
    return user


async def get_current_active_user(
    current_user: User = Security(get_current_user, scopes=["me"]),
):
    if current_user.disabled:
        raise HTTPException(status_code=400, detail="Inactive user")
    return current_user


@app.post("/token")
async def login_for_access_token(
    form_data: OAuth2PasswordRequestForm = Depends(),
) -> Token:
    user = authenticate_user(fake_users_db, form_data.username, form_data.password)
    if not user:
        raise HTTPException(status_code=400, detail="Incorrect username or password")
    access_token_expires = timedelta(minutes=ACCESS_TOKEN_EXPIRE_MINUTES)
    access_token = create_access_token(
        data={"sub": user.username, "scope": " ".join(form_data.scopes)},
        expires_delta=access_token_expires,
    )
    return Token(access_token=access_token, token_type="bearer")


@app.get("/users/me/", response_model=User)
async def read_users_me(current_user: User = Depends(get_current_active_user)):
    return current_user


@app.get("/users/me/items/")
async def read_own_items(
    current_user: User = Security(get_current_active_user, scopes=["items"]),
):
    return [{"item_id": "Foo", "owner": current_user.username}]


@app.get("/status/")
async def read_system_status(current_user: User = Depends(get_current_user)):
    return {"status": "ok"}

ヒント

可能であれば`Annotated`バージョンを使用することをお勧めします。

from datetime import datetime, timedelta, timezone
from typing import Union

import jwt
from fastapi import Depends, FastAPI, HTTPException, Security, status
from fastapi.security import (
    OAuth2PasswordBearer,
    OAuth2PasswordRequestForm,
    SecurityScopes,
)
from jwt.exceptions import InvalidTokenError
from pwdlib import PasswordHash
from pydantic import BaseModel, ValidationError

# to get a string like this run:
# openssl rand -hex 32
SECRET_KEY = "09d25e094faa6ca2556c818166b7a9563b93f7099f6f0f4caa6cf63b88e8d3e7"
ALGORITHM = "HS256"
ACCESS_TOKEN_EXPIRE_MINUTES = 30


fake_users_db = {
    "johndoe": {
        "username": "johndoe",
        "full_name": "John Doe",
        "email": "johndoe@example.com",
        "hashed_password": "$argon2id$v=19$m=65536,t=3,p=4$wagCPXjifgvUFBzq4hqe3w$CYaIb8sB+wtD+Vu/P4uod1+Qof8h+1g7bbDlBID48Rc",
        "disabled": False,
    },
    "alice": {
        "username": "alice",
        "full_name": "Alice Chains",
        "email": "alicechains@example.com",
        "hashed_password": "$argon2id$v=19$m=65536,t=3,p=4$g2/AV1zwopqUntPKJavBFw$BwpRGDCyUHLvHICnwijyX8ROGoiUPwNKZ7915MeYfCE",
        "disabled": True,
    },
}


class Token(BaseModel):
    access_token: str
    token_type: str


class TokenData(BaseModel):
    username: Union[str, None] = None
    scopes: list[str] = []


class User(BaseModel):
    username: str
    email: Union[str, None] = None
    full_name: Union[str, None] = None
    disabled: Union[bool, None] = None


class UserInDB(User):
    hashed_password: str


password_hash = PasswordHash.recommended()

oauth2_scheme = OAuth2PasswordBearer(
    tokenUrl="token",
    scopes={"me": "Read information about the current user.", "items": "Read items."},
)

app = FastAPI()


def verify_password(plain_password, hashed_password):
    return password_hash.verify(plain_password, hashed_password)


def get_password_hash(password):
    return password_hash.hash(password)


def get_user(db, username: str):
    if username in db:
        user_dict = db[username]
        return UserInDB(**user_dict)


def authenticate_user(fake_db, username: str, password: str):
    user = get_user(fake_db, username)
    if not user:
        return False
    if not verify_password(password, user.hashed_password):
        return False
    return user


def create_access_token(data: dict, expires_delta: Union[timedelta, None] = None):
    to_encode = data.copy()
    if expires_delta:
        expire = datetime.now(timezone.utc) + expires_delta
    else:
        expire = datetime.now(timezone.utc) + timedelta(minutes=15)
    to_encode.update({"exp": expire})
    encoded_jwt = jwt.encode(to_encode, SECRET_KEY, algorithm=ALGORITHM)
    return encoded_jwt


async def get_current_user(
    security_scopes: SecurityScopes, token: str = Depends(oauth2_scheme)
):
    if security_scopes.scopes:
        authenticate_value = f'Bearer scope="{security_scopes.scope_str}"'
    else:
        authenticate_value = "Bearer"
    credentials_exception = HTTPException(
        status_code=status.HTTP_401_UNAUTHORIZED,
        detail="Could not validate credentials",
        headers={"WWW-Authenticate": authenticate_value},
    )
    try:
        payload = jwt.decode(token, SECRET_KEY, algorithms=[ALGORITHM])
        username: str = payload.get("sub")
        if username is None:
            raise credentials_exception
        scope: str = payload.get("scope", "")
        token_scopes = scope.split(" ")
        token_data = TokenData(scopes=token_scopes, username=username)
    except (InvalidTokenError, ValidationError):
        raise credentials_exception
    user = get_user(fake_users_db, username=token_data.username)
    if user is None:
        raise credentials_exception
    for scope in security_scopes.scopes:
        if scope not in token_data.scopes:
            raise HTTPException(
                status_code=status.HTTP_401_UNAUTHORIZED,
                detail="Not enough permissions",
                headers={"WWW-Authenticate": authenticate_value},
            )
    return user


async def get_current_active_user(
    current_user: User = Security(get_current_user, scopes=["me"]),
):
    if current_user.disabled:
        raise HTTPException(status_code=400, detail="Inactive user")
    return current_user


@app.post("/token")
async def login_for_access_token(
    form_data: OAuth2PasswordRequestForm = Depends(),
) -> Token:
    user = authenticate_user(fake_users_db, form_data.username, form_data.password)
    if not user:
        raise HTTPException(status_code=400, detail="Incorrect username or password")
    access_token_expires = timedelta(minutes=ACCESS_TOKEN_EXPIRE_MINUTES)
    access_token = create_access_token(
        data={"sub": user.username, "scope": " ".join(form_data.scopes)},
        expires_delta=access_token_expires,
    )
    return Token(access_token=access_token, token_type="bearer")


@app.get("/users/me/", response_model=User)
async def read_users_me(current_user: User = Depends(get_current_active_user)):
    return current_user


@app.get("/users/me/items/")
async def read_own_items(
    current_user: User = Security(get_current_active_user, scopes=["items"]),
):
    return [{"item_id": "Foo", "owner": current_user.username}]


@app.get("/status/")
async def read_system_status(current_user: User = Depends(get_current_user)):
    return {"status": "ok"}

ヒント

可能であれば`Annotated`バージョンを使用することをお勧めします。

from datetime import datetime, timedelta, timezone
from typing import List, Union

import jwt
from fastapi import Depends, FastAPI, HTTPException, Security, status
from fastapi.security import (
    OAuth2PasswordBearer,
    OAuth2PasswordRequestForm,
    SecurityScopes,
)
from jwt.exceptions import InvalidTokenError
from pwdlib import PasswordHash
from pydantic import BaseModel, ValidationError

# to get a string like this run:
# openssl rand -hex 32
SECRET_KEY = "09d25e094faa6ca2556c818166b7a9563b93f7099f6f0f4caa6cf63b88e8d3e7"
ALGORITHM = "HS256"
ACCESS_TOKEN_EXPIRE_MINUTES = 30


fake_users_db = {
    "johndoe": {
        "username": "johndoe",
        "full_name": "John Doe",
        "email": "johndoe@example.com",
        "hashed_password": "$argon2id$v=19$m=65536,t=3,p=4$wagCPXjifgvUFBzq4hqe3w$CYaIb8sB+wtD+Vu/P4uod1+Qof8h+1g7bbDlBID48Rc",
        "disabled": False,
    },
    "alice": {
        "username": "alice",
        "full_name": "Alice Chains",
        "email": "alicechains@example.com",
        "hashed_password": "$argon2id$v=19$m=65536,t=3,p=4$g2/AV1zwopqUntPKJavBFw$BwpRGDCyUHLvHICnwijyX8ROGoiUPwNKZ7915MeYfCE",
        "disabled": True,
    },
}


class Token(BaseModel):
    access_token: str
    token_type: str


class TokenData(BaseModel):
    username: Union[str, None] = None
    scopes: List[str] = []


class User(BaseModel):
    username: str
    email: Union[str, None] = None
    full_name: Union[str, None] = None
    disabled: Union[bool, None] = None


class UserInDB(User):
    hashed_password: str


password_hash = PasswordHash.recommended()

oauth2_scheme = OAuth2PasswordBearer(
    tokenUrl="token",
    scopes={"me": "Read information about the current user.", "items": "Read items."},
)

app = FastAPI()


def verify_password(plain_password, hashed_password):
    return password_hash.verify(plain_password, hashed_password)


def get_password_hash(password):
    return password_hash.hash(password)


def get_user(db, username: str):
    if username in db:
        user_dict = db[username]
        return UserInDB(**user_dict)


def authenticate_user(fake_db, username: str, password: str):
    user = get_user(fake_db, username)
    if not user:
        return False
    if not verify_password(password, user.hashed_password):
        return False
    return user


def create_access_token(data: dict, expires_delta: Union[timedelta, None] = None):
    to_encode = data.copy()
    if expires_delta:
        expire = datetime.now(timezone.utc) + expires_delta
    else:
        expire = datetime.now(timezone.utc) + timedelta(minutes=15)
    to_encode.update({"exp": expire})
    encoded_jwt = jwt.encode(to_encode, SECRET_KEY, algorithm=ALGORITHM)
    return encoded_jwt


async def get_current_user(
    security_scopes: SecurityScopes, token: str = Depends(oauth2_scheme)
):
    if security_scopes.scopes:
        authenticate_value = f'Bearer scope="{security_scopes.scope_str}"'
    else:
        authenticate_value = "Bearer"
    credentials_exception = HTTPException(
        status_code=status.HTTP_401_UNAUTHORIZED,
        detail="Could not validate credentials",
        headers={"WWW-Authenticate": authenticate_value},
    )
    try:
        payload = jwt.decode(token, SECRET_KEY, algorithms=[ALGORITHM])
        username: str = payload.get("sub")
        if username is None:
            raise credentials_exception
        scope: str = payload.get("scope", "")
        token_scopes = scope.split(" ")
        token_data = TokenData(scopes=token_scopes, username=username)
    except (InvalidTokenError, ValidationError):
        raise credentials_exception
    user = get_user(fake_users_db, username=token_data.username)
    if user is None:
        raise credentials_exception
    for scope in security_scopes.scopes:
        if scope not in token_data.scopes:
            raise HTTPException(
                status_code=status.HTTP_401_UNAUTHORIZED,
                detail="Not enough permissions",
                headers={"WWW-Authenticate": authenticate_value},
            )
    return user


async def get_current_active_user(
    current_user: User = Security(get_current_user, scopes=["me"]),
):
    if current_user.disabled:
        raise HTTPException(status_code=400, detail="Inactive user")
    return current_user


@app.post("/token")
async def login_for_access_token(
    form_data: OAuth2PasswordRequestForm = Depends(),
) -> Token:
    user = authenticate_user(fake_users_db, form_data.username, form_data.password)
    if not user:
        raise HTTPException(status_code=400, detail="Incorrect username or password")
    access_token_expires = timedelta(minutes=ACCESS_TOKEN_EXPIRE_MINUTES)
    access_token = create_access_token(
        data={"sub": user.username, "scope": " ".join(form_data.scopes)},
        expires_delta=access_token_expires,
    )
    return Token(access_token=access_token, token_type="bearer")


@app.get("/users/me/", response_model=User)
async def read_users_me(current_user: User = Depends(get_current_active_user)):
    return current_user


@app.get("/users/me/items/")
async def read_own_items(
    current_user: User = Security(get_current_active_user, scopes=["items"]),
):
    return [{"item_id": "Foo", "owner": current_user.username}]


@app.get("/status/")
async def read_system_status(current_user: User = Depends(get_current_user)):
    return {"status": "ok"}

usernameとデータ形状を検証する

usernameを取得し、スコープを抽出したことを確認します。

そして、Pydanticモデルでそのデータを検証し（ValidationError例外をキャッチ）、JWTトークンの読み取りまたはPydanticでのデータ検証でエラーが発生した場合は、以前に作成したHTTPExceptionを発生させます。

そのために、PydanticモデルTokenDataに新しいプロパティscopesを追加して更新します。

Pydanticでデータを検証することで、例えば、スコープを持つstrのlistとusernameを持つstrが正確に存在することを確認できます。

例えば、dictやその他のものではなく、アプリケーションを後でどこかで破壊する可能性があり、セキュリティリスクとなる可能性があります。

また、そのユーザー名を持つユーザーが存在することを確認し、存在しない場合は、以前に作成した同じ例外を発生させます。

Python 3.10+

from datetime import datetime, timedelta, timezone
from typing import Annotated

import jwt
from fastapi import Depends, FastAPI, HTTPException, Security, status
from fastapi.security import (
    OAuth2PasswordBearer,
    OAuth2PasswordRequestForm,
    SecurityScopes,
)
from jwt.exceptions import InvalidTokenError
from pwdlib import PasswordHash
from pydantic import BaseModel, ValidationError

# to get a string like this run:
# openssl rand -hex 32
SECRET_KEY = "09d25e094faa6ca2556c818166b7a9563b93f7099f6f0f4caa6cf63b88e8d3e7"
ALGORITHM = "HS256"
ACCESS_TOKEN_EXPIRE_MINUTES = 30


fake_users_db = {
    "johndoe": {
        "username": "johndoe",
        "full_name": "John Doe",
        "email": "johndoe@example.com",
        "hashed_password": "$argon2id$v=19$m=65536,t=3,p=4$wagCPXjifgvUFBzq4hqe3w$CYaIb8sB+wtD+Vu/P4uod1+Qof8h+1g7bbDlBID48Rc",
        "disabled": False,
    },
    "alice": {
        "username": "alice",
        "full_name": "Alice Chains",
        "email": "alicechains@example.com",
        "hashed_password": "$argon2id$v=19$m=65536,t=3,p=4$g2/AV1zwopqUntPKJavBFw$BwpRGDCyUHLvHICnwijyX8ROGoiUPwNKZ7915MeYfCE",
        "disabled": True,
    },
}


class Token(BaseModel):
    access_token: str
    token_type: str


class TokenData(BaseModel):
    username: str | None = None
    scopes: list[str] = []


class User(BaseModel):
    username: str
    email: str | None = None
    full_name: str | None = None
    disabled: bool | None = None


class UserInDB(User):
    hashed_password: str


password_hash = PasswordHash.recommended()

oauth2_scheme = OAuth2PasswordBearer(
    tokenUrl="token",
    scopes={"me": "Read information about the current user.", "items": "Read items."},
)

app = FastAPI()


def verify_password(plain_password, hashed_password):
    return password_hash.verify(plain_password, hashed_password)


def get_password_hash(password):
    return password_hash.hash(password)


def get_user(db, username: str):
    if username in db:
        user_dict = db[username]
        return UserInDB(**user_dict)


def authenticate_user(fake_db, username: str, password: str):
    user = get_user(fake_db, username)
    if not user:
        return False
    if not verify_password(password, user.hashed_password):
        return False
    return user


def create_access_token(data: dict, expires_delta: timedelta | None = None):
    to_encode = data.copy()
    if expires_delta:
        expire = datetime.now(timezone.utc) + expires_delta
    else:
        expire = datetime.now(timezone.utc) + timedelta(minutes=15)
    to_encode.update({"exp": expire})
    encoded_jwt = jwt.encode(to_encode, SECRET_KEY, algorithm=ALGORITHM)
    return encoded_jwt


async def get_current_user(
    security_scopes: SecurityScopes, token: Annotated[str, Depends(oauth2_scheme)]
):
    if security_scopes.scopes:
        authenticate_value = f'Bearer scope="{security_scopes.scope_str}"'
    else:
        authenticate_value = "Bearer"
    credentials_exception = HTTPException(
        status_code=status.HTTP_401_UNAUTHORIZED,
        detail="Could not validate credentials",
        headers={"WWW-Authenticate": authenticate_value},
    )
    try:
        payload = jwt.decode(token, SECRET_KEY, algorithms=[ALGORITHM])
        username = payload.get("sub")
        if username is None:
            raise credentials_exception
        scope: str = payload.get("scope", "")
        token_scopes = scope.split(" ")
        token_data = TokenData(scopes=token_scopes, username=username)
    except (InvalidTokenError, ValidationError):
        raise credentials_exception
    user = get_user(fake_users_db, username=token_data.username)
    if user is None:
        raise credentials_exception
    for scope in security_scopes.scopes:
        if scope not in token_data.scopes:
            raise HTTPException(
                status_code=status.HTTP_401_UNAUTHORIZED,
                detail="Not enough permissions",
                headers={"WWW-Authenticate": authenticate_value},
            )
    return user


async def get_current_active_user(
    current_user: Annotated[User, Security(get_current_user, scopes=["me"])],
):
    if current_user.disabled:
        raise HTTPException(status_code=400, detail="Inactive user")
    return current_user


@app.post("/token")
async def login_for_access_token(
    form_data: Annotated[OAuth2PasswordRequestForm, Depends()],
) -> Token:
    user = authenticate_user(fake_users_db, form_data.username, form_data.password)
    if not user:
        raise HTTPException(status_code=400, detail="Incorrect username or password")
    access_token_expires = timedelta(minutes=ACCESS_TOKEN_EXPIRE_MINUTES)
    access_token = create_access_token(
        data={"sub": user.username, "scope": " ".join(form_data.scopes)},
        expires_delta=access_token_expires,
    )
    return Token(access_token=access_token, token_type="bearer")


@app.get("/users/me/", response_model=User)
async def read_users_me(
    current_user: Annotated[User, Depends(get_current_active_user)],
):
    return current_user


@app.get("/users/me/items/")
async def read_own_items(
    current_user: Annotated[User, Security(get_current_active_user, scopes=["items"])],
):
    return [{"item_id": "Foo", "owner": current_user.username}]


@app.get("/status/")
async def read_system_status(current_user: Annotated[User, Depends(get_current_user)]):
    return {"status": "ok"}

🤓 その他のバージョンとバリアント

Python 3.9+Python 3.8+Python 3.10+ - non-AnnotatedPython 3.9+ - 非注釈付きPython 3.8+ - non-Annotated

from datetime import datetime, timedelta, timezone
from typing import Annotated, Union

import jwt
from fastapi import Depends, FastAPI, HTTPException, Security, status
from fastapi.security import (
    OAuth2PasswordBearer,
    OAuth2PasswordRequestForm,
    SecurityScopes,
)
from jwt.exceptions import InvalidTokenError
from pwdlib import PasswordHash
from pydantic import BaseModel, ValidationError

# to get a string like this run:
# openssl rand -hex 32
SECRET_KEY = "09d25e094faa6ca2556c818166b7a9563b93f7099f6f0f4caa6cf63b88e8d3e7"
ALGORITHM = "HS256"
ACCESS_TOKEN_EXPIRE_MINUTES = 30


fake_users_db = {
    "johndoe": {
        "username": "johndoe",
        "full_name": "John Doe",
        "email": "johndoe@example.com",
        "hashed_password": "$argon2id$v=19$m=65536,t=3,p=4$wagCPXjifgvUFBzq4hqe3w$CYaIb8sB+wtD+Vu/P4uod1+Qof8h+1g7bbDlBID48Rc",
        "disabled": False,
    },
    "alice": {
        "username": "alice",
        "full_name": "Alice Chains",
        "email": "alicechains@example.com",
        "hashed_password": "$argon2id$v=19$m=65536,t=3,p=4$g2/AV1zwopqUntPKJavBFw$BwpRGDCyUHLvHICnwijyX8ROGoiUPwNKZ7915MeYfCE",
        "disabled": True,
    },
}


class Token(BaseModel):
    access_token: str
    token_type: str


class TokenData(BaseModel):
    username: Union[str, None] = None
    scopes: list[str] = []


class User(BaseModel):
    username: str
    email: Union[str, None] = None
    full_name: Union[str, None] = None
    disabled: Union[bool, None] = None


class UserInDB(User):
    hashed_password: str


password_hash = PasswordHash.recommended()

oauth2_scheme = OAuth2PasswordBearer(
    tokenUrl="token",
    scopes={"me": "Read information about the current user.", "items": "Read items."},
)

app = FastAPI()


def verify_password(plain_password, hashed_password):
    return password_hash.verify(plain_password, hashed_password)


def get_password_hash(password):
    return password_hash.hash(password)


def get_user(db, username: str):
    if username in db:
        user_dict = db[username]
        return UserInDB(**user_dict)


def authenticate_user(fake_db, username: str, password: str):
    user = get_user(fake_db, username)
    if not user:
        return False
    if not verify_password(password, user.hashed_password):
        return False
    return user


def create_access_token(data: dict, expires_delta: Union[timedelta, None] = None):
    to_encode = data.copy()
    if expires_delta:
        expire = datetime.now(timezone.utc) + expires_delta
    else:
        expire = datetime.now(timezone.utc) + timedelta(minutes=15)
    to_encode.update({"exp": expire})
    encoded_jwt = jwt.encode(to_encode, SECRET_KEY, algorithm=ALGORITHM)
    return encoded_jwt


async def get_current_user(
    security_scopes: SecurityScopes, token: Annotated[str, Depends(oauth2_scheme)]
):
    if security_scopes.scopes:
        authenticate_value = f'Bearer scope="{security_scopes.scope_str}"'
    else:
        authenticate_value = "Bearer"
    credentials_exception = HTTPException(
        status_code=status.HTTP_401_UNAUTHORIZED,
        detail="Could not validate credentials",
        headers={"WWW-Authenticate": authenticate_value},
    )
    try:
        payload = jwt.decode(token, SECRET_KEY, algorithms=[ALGORITHM])
        username = payload.get("sub")
        if username is None:
            raise credentials_exception
        scope: str = payload.get("scope", "")
        token_scopes = scope.split(" ")
        token_data = TokenData(scopes=token_scopes, username=username)
    except (InvalidTokenError, ValidationError):
        raise credentials_exception
    user = get_user(fake_users_db, username=token_data.username)
    if user is None:
        raise credentials_exception
    for scope in security_scopes.scopes:
        if scope not in token_data.scopes:
            raise HTTPException(
                status_code=status.HTTP_401_UNAUTHORIZED,
                detail="Not enough permissions",
                headers={"WWW-Authenticate": authenticate_value},
            )
    return user


async def get_current_active_user(
    current_user: Annotated[User, Security(get_current_user, scopes=["me"])],
):
    if current_user.disabled:
        raise HTTPException(status_code=400, detail="Inactive user")
    return current_user


@app.post("/token")
async def login_for_access_token(
    form_data: Annotated[OAuth2PasswordRequestForm, Depends()],
) -> Token:
    user = authenticate_user(fake_users_db, form_data.username, form_data.password)
    if not user:
        raise HTTPException(status_code=400, detail="Incorrect username or password")
    access_token_expires = timedelta(minutes=ACCESS_TOKEN_EXPIRE_MINUTES)
    access_token = create_access_token(
        data={"sub": user.username, "scope": " ".join(form_data.scopes)},
        expires_delta=access_token_expires,
    )
    return Token(access_token=access_token, token_type="bearer")


@app.get("/users/me/", response_model=User)
async def read_users_me(
    current_user: Annotated[User, Depends(get_current_active_user)],
):
    return current_user


@app.get("/users/me/items/")
async def read_own_items(
    current_user: Annotated[User, Security(get_current_active_user, scopes=["items"])],
):
    return [{"item_id": "Foo", "owner": current_user.username}]


@app.get("/status/")
async def read_system_status(current_user: Annotated[User, Depends(get_current_user)]):
    return {"status": "ok"}

from datetime import datetime, timedelta, timezone
from typing import List, Union

import jwt
from fastapi import Depends, FastAPI, HTTPException, Security, status
from fastapi.security import (
    OAuth2PasswordBearer,
    OAuth2PasswordRequestForm,
    SecurityScopes,
)
from jwt.exceptions import InvalidTokenError
from pwdlib import PasswordHash
from pydantic import BaseModel, ValidationError
from typing_extensions import Annotated

# to get a string like this run:
# openssl rand -hex 32
SECRET_KEY = "09d25e094faa6ca2556c818166b7a9563b93f7099f6f0f4caa6cf63b88e8d3e7"
ALGORITHM = "HS256"
ACCESS_TOKEN_EXPIRE_MINUTES = 30


fake_users_db = {
    "johndoe": {
        "username": "johndoe",
        "full_name": "John Doe",
        "email": "johndoe@example.com",
        "hashed_password": "$argon2id$v=19$m=65536,t=3,p=4$wagCPXjifgvUFBzq4hqe3w$CYaIb8sB+wtD+Vu/P4uod1+Qof8h+1g7bbDlBID48Rc",
        "disabled": False,
    },
    "alice": {
        "username": "alice",
        "full_name": "Alice Chains",
        "email": "alicechains@example.com",
        "hashed_password": "$argon2id$v=19$m=65536,t=3,p=4$g2/AV1zwopqUntPKJavBFw$BwpRGDCyUHLvHICnwijyX8ROGoiUPwNKZ7915MeYfCE",
        "disabled": True,
    },
}


class Token(BaseModel):
    access_token: str
    token_type: str


class TokenData(BaseModel):
    username: Union[str, None] = None
    scopes: List[str] = []


class User(BaseModel):
    username: str
    email: Union[str, None] = None
    full_name: Union[str, None] = None
    disabled: Union[bool, None] = None


class UserInDB(User):
    hashed_password: str


password_hash = PasswordHash.recommended()

oauth2_scheme = OAuth2PasswordBearer(
    tokenUrl="token",
    scopes={"me": "Read information about the current user.", "items": "Read items."},
)

app = FastAPI()


def verify_password(plain_password, hashed_password):
    return password_hash.verify(plain_password, hashed_password)


def get_password_hash(password):
    return password_hash.hash(password)


def get_user(db, username: str):
    if username in db:
        user_dict = db[username]
        return UserInDB(**user_dict)


def authenticate_user(fake_db, username: str, password: str):
    user = get_user(fake_db, username)
    if not user:
        return False
    if not verify_password(password, user.hashed_password):
        return False
    return user


def create_access_token(data: dict, expires_delta: Union[timedelta, None] = None):
    to_encode = data.copy()
    if expires_delta:
        expire = datetime.now(timezone.utc) + expires_delta
    else:
        expire = datetime.now(timezone.utc) + timedelta(minutes=15)
    to_encode.update({"exp": expire})
    encoded_jwt = jwt.encode(to_encode, SECRET_KEY, algorithm=ALGORITHM)
    return encoded_jwt


async def get_current_user(
    security_scopes: SecurityScopes, token: Annotated[str, Depends(oauth2_scheme)]
):
    if security_scopes.scopes:
        authenticate_value = f'Bearer scope="{security_scopes.scope_str}"'
    else:
        authenticate_value = "Bearer"
    credentials_exception = HTTPException(
        status_code=status.HTTP_401_UNAUTHORIZED,
        detail="Could not validate credentials",
        headers={"WWW-Authenticate": authenticate_value},
    )
    try:
        payload = jwt.decode(token, SECRET_KEY, algorithms=[ALGORITHM])
        username = payload.get("sub")
        if username is None:
            raise credentials_exception
        scope: str = payload.get("scope", "")
        token_scopes = scope.split(" ")
        token_data = TokenData(scopes=token_scopes, username=username)
    except (InvalidTokenError, ValidationError):
        raise credentials_exception
    user = get_user(fake_users_db, username=token_data.username)
    if user is None:
        raise credentials_exception
    for scope in security_scopes.scopes:
        if scope not in token_data.scopes:
            raise HTTPException(
                status_code=status.HTTP_401_UNAUTHORIZED,
                detail="Not enough permissions",
                headers={"WWW-Authenticate": authenticate_value},
            )
    return user


async def get_current_active_user(
    current_user: Annotated[User, Security(get_current_user, scopes=["me"])],
):
    if current_user.disabled:
        raise HTTPException(status_code=400, detail="Inactive user")
    return current_user


@app.post("/token")
async def login_for_access_token(
    form_data: Annotated[OAuth2PasswordRequestForm, Depends()],
) -> Token:
    user = authenticate_user(fake_users_db, form_data.username, form_data.password)
    if not user:
        raise HTTPException(status_code=400, detail="Incorrect username or password")
    access_token_expires = timedelta(minutes=ACCESS_TOKEN_EXPIRE_MINUTES)
    access_token = create_access_token(
        data={"sub": user.username, "scope": " ".join(form_data.scopes)},
        expires_delta=access_token_expires,
    )
    return Token(access_token=access_token, token_type="bearer")


@app.get("/users/me/", response_model=User)
async def read_users_me(
    current_user: Annotated[User, Depends(get_current_active_user)],
):
    return current_user


@app.get("/users/me/items/")
async def read_own_items(
    current_user: Annotated[User, Security(get_current_active_user, scopes=["items"])],
):
    return [{"item_id": "Foo", "owner": current_user.username}]


@app.get("/status/")
async def read_system_status(current_user: Annotated[User, Depends(get_current_user)]):
    return {"status": "ok"}

ヒント

可能であれば`Annotated`バージョンを使用することをお勧めします。

from datetime import datetime, timedelta, timezone

import jwt
from fastapi import Depends, FastAPI, HTTPException, Security, status
from fastapi.security import (
    OAuth2PasswordBearer,
    OAuth2PasswordRequestForm,
    SecurityScopes,
)
from jwt.exceptions import InvalidTokenError
from pwdlib import PasswordHash
from pydantic import BaseModel, ValidationError

# to get a string like this run:
# openssl rand -hex 32
SECRET_KEY = "09d25e094faa6ca2556c818166b7a9563b93f7099f6f0f4caa6cf63b88e8d3e7"
ALGORITHM = "HS256"
ACCESS_TOKEN_EXPIRE_MINUTES = 30


fake_users_db = {
    "johndoe": {
        "username": "johndoe",
        "full_name": "John Doe",
        "email": "johndoe@example.com",
        "hashed_password": "$argon2id$v=19$m=65536,t=3,p=4$wagCPXjifgvUFBzq4hqe3w$CYaIb8sB+wtD+Vu/P4uod1+Qof8h+1g7bbDlBID48Rc",
        "disabled": False,
    },
    "alice": {
        "username": "alice",
        "full_name": "Alice Chains",
        "email": "alicechains@example.com",
        "hashed_password": "$argon2id$v=19$m=65536,t=3,p=4$g2/AV1zwopqUntPKJavBFw$BwpRGDCyUHLvHICnwijyX8ROGoiUPwNKZ7915MeYfCE",
        "disabled": True,
    },
}


class Token(BaseModel):
    access_token: str
    token_type: str


class TokenData(BaseModel):
    username: str | None = None
    scopes: list[str] = []


class User(BaseModel):
    username: str
    email: str | None = None
    full_name: str | None = None
    disabled: bool | None = None


class UserInDB(User):
    hashed_password: str


password_hash = PasswordHash.recommended()

oauth2_scheme = OAuth2PasswordBearer(
    tokenUrl="token",
    scopes={"me": "Read information about the current user.", "items": "Read items."},
)

app = FastAPI()


def verify_password(plain_password, hashed_password):
    return password_hash.verify(plain_password, hashed_password)


def get_password_hash(password):
    return password_hash.hash(password)


def get_user(db, username: str):
    if username in db:
        user_dict = db[username]
        return UserInDB(**user_dict)


def authenticate_user(fake_db, username: str, password: str):
    user = get_user(fake_db, username)
    if not user:
        return False
    if not verify_password(password, user.hashed_password):
        return False
    return user


def create_access_token(data: dict, expires_delta: timedelta | None = None):
    to_encode = data.copy()
    if expires_delta:
        expire = datetime.now(timezone.utc) + expires_delta
    else:
        expire = datetime.now(timezone.utc) + timedelta(minutes=15)
    to_encode.update({"exp": expire})
    encoded_jwt = jwt.encode(to_encode, SECRET_KEY, algorithm=ALGORITHM)
    return encoded_jwt


async def get_current_user(
    security_scopes: SecurityScopes, token: str = Depends(oauth2_scheme)
):
    if security_scopes.scopes:
        authenticate_value = f'Bearer scope="{security_scopes.scope_str}"'
    else:
        authenticate_value = "Bearer"
    credentials_exception = HTTPException(
        status_code=status.HTTP_401_UNAUTHORIZED,
        detail="Could not validate credentials",
        headers={"WWW-Authenticate": authenticate_value},
    )
    try:
        payload = jwt.decode(token, SECRET_KEY, algorithms=[ALGORITHM])
        username: str = payload.get("sub")
        if username is None:
            raise credentials_exception
        scope: str = payload.get("scope", "")
        token_scopes = scope.split(" ")
        token_data = TokenData(scopes=token_scopes, username=username)
    except (InvalidTokenError, ValidationError):
        raise credentials_exception
    user = get_user(fake_users_db, username=token_data.username)
    if user is None:
        raise credentials_exception
    for scope in security_scopes.scopes:
        if scope not in token_data.scopes:
            raise HTTPException(
                status_code=status.HTTP_401_UNAUTHORIZED,
                detail="Not enough permissions",
                headers={"WWW-Authenticate": authenticate_value},
            )
    return user


async def get_current_active_user(
    current_user: User = Security(get_current_user, scopes=["me"]),
):
    if current_user.disabled:
        raise HTTPException(status_code=400, detail="Inactive user")
    return current_user


@app.post("/token")
async def login_for_access_token(
    form_data: OAuth2PasswordRequestForm = Depends(),
) -> Token:
    user = authenticate_user(fake_users_db, form_data.username, form_data.password)
    if not user:
        raise HTTPException(status_code=400, detail="Incorrect username or password")
    access_token_expires = timedelta(minutes=ACCESS_TOKEN_EXPIRE_MINUTES)
    access_token = create_access_token(
        data={"sub": user.username, "scope": " ".join(form_data.scopes)},
        expires_delta=access_token_expires,
    )
    return Token(access_token=access_token, token_type="bearer")


@app.get("/users/me/", response_model=User)
async def read_users_me(current_user: User = Depends(get_current_active_user)):
    return current_user


@app.get("/users/me/items/")
async def read_own_items(
    current_user: User = Security(get_current_active_user, scopes=["items"]),
):
    return [{"item_id": "Foo", "owner": current_user.username}]


@app.get("/status/")
async def read_system_status(current_user: User = Depends(get_current_user)):
    return {"status": "ok"}

ヒント

可能であれば`Annotated`バージョンを使用することをお勧めします。

from datetime import datetime, timedelta, timezone
from typing import Union

import jwt
from fastapi import Depends, FastAPI, HTTPException, Security, status
from fastapi.security import (
    OAuth2PasswordBearer,
    OAuth2PasswordRequestForm,
    SecurityScopes,
)
from jwt.exceptions import InvalidTokenError
from pwdlib import PasswordHash
from pydantic import BaseModel, ValidationError

# to get a string like this run:
# openssl rand -hex 32
SECRET_KEY = "09d25e094faa6ca2556c818166b7a9563b93f7099f6f0f4caa6cf63b88e8d3e7"
ALGORITHM = "HS256"
ACCESS_TOKEN_EXPIRE_MINUTES = 30


fake_users_db = {
    "johndoe": {
        "username": "johndoe",
        "full_name": "John Doe",
        "email": "johndoe@example.com",
        "hashed_password": "$argon2id$v=19$m=65536,t=3,p=4$wagCPXjifgvUFBzq4hqe3w$CYaIb8sB+wtD+Vu/P4uod1+Qof8h+1g7bbDlBID48Rc",
        "disabled": False,
    },
    "alice": {
        "username": "alice",
        "full_name": "Alice Chains",
        "email": "alicechains@example.com",
        "hashed_password": "$argon2id$v=19$m=65536,t=3,p=4$g2/AV1zwopqUntPKJavBFw$BwpRGDCyUHLvHICnwijyX8ROGoiUPwNKZ7915MeYfCE",
        "disabled": True,
    },
}


class Token(BaseModel):
    access_token: str
    token_type: str


class TokenData(BaseModel):
    username: Union[str, None] = None
    scopes: list[str] = []


class User(BaseModel):
    username: str
    email: Union[str, None] = None
    full_name: Union[str, None] = None
    disabled: Union[bool, None] = None


class UserInDB(User):
    hashed_password: str


password_hash = PasswordHash.recommended()

oauth2_scheme = OAuth2PasswordBearer(
    tokenUrl="token",
    scopes={"me": "Read information about the current user.", "items": "Read items."},
)

app = FastAPI()


def verify_password(plain_password, hashed_password):
    return password_hash.verify(plain_password, hashed_password)


def get_password_hash(password):
    return password_hash.hash(password)


def get_user(db, username: str):
    if username in db:
        user_dict = db[username]
        return UserInDB(**user_dict)


def authenticate_user(fake_db, username: str, password: str):
    user = get_user(fake_db, username)
    if not user:
        return False
    if not verify_password(password, user.hashed_password):
        return False
    return user


def create_access_token(data: dict, expires_delta: Union[timedelta, None] = None):
    to_encode = data.copy()
    if expires_delta:
        expire = datetime.now(timezone.utc) + expires_delta
    else:
        expire = datetime.now(timezone.utc) + timedelta(minutes=15)
    to_encode.update({"exp": expire})
    encoded_jwt = jwt.encode(to_encode, SECRET_KEY, algorithm=ALGORITHM)
    return encoded_jwt


async def get_current_user(
    security_scopes: SecurityScopes, token: str = Depends(oauth2_scheme)
):
    if security_scopes.scopes:
        authenticate_value = f'Bearer scope="{security_scopes.scope_str}"'
    else:
        authenticate_value = "Bearer"
    credentials_exception = HTTPException(
        status_code=status.HTTP_401_UNAUTHORIZED,
        detail="Could not validate credentials",
        headers={"WWW-Authenticate": authenticate_value},
    )
    try:
        payload = jwt.decode(token, SECRET_KEY, algorithms=[ALGORITHM])
        username: str = payload.get("sub")
        if username is None:
            raise credentials_exception
        scope: str = payload.get("scope", "")
        token_scopes = scope.split(" ")
        token_data = TokenData(scopes=token_scopes, username=username)
    except (InvalidTokenError, ValidationError):
        raise credentials_exception
    user = get_user(fake_users_db, username=token_data.username)
    if user is None:
        raise credentials_exception
    for scope in security_scopes.scopes:
        if scope not in token_data.scopes:
            raise HTTPException(
                status_code=status.HTTP_401_UNAUTHORIZED,
                detail="Not enough permissions",
                headers={"WWW-Authenticate": authenticate_value},
            )
    return user


async def get_current_active_user(
    current_user: User = Security(get_current_user, scopes=["me"]),
):
    if current_user.disabled:
        raise HTTPException(status_code=400, detail="Inactive user")
    return current_user


@app.post("/token")
async def login_for_access_token(
    form_data: OAuth2PasswordRequestForm = Depends(),
) -> Token:
    user = authenticate_user(fake_users_db, form_data.username, form_data.password)
    if not user:
        raise HTTPException(status_code=400, detail="Incorrect username or password")
    access_token_expires = timedelta(minutes=ACCESS_TOKEN_EXPIRE_MINUTES)
    access_token = create_access_token(
        data={"sub": user.username, "scope": " ".join(form_data.scopes)},
        expires_delta=access_token_expires,
    )
    return Token(access_token=access_token, token_type="bearer")


@app.get("/users/me/", response_model=User)
async def read_users_me(current_user: User = Depends(get_current_active_user)):
    return current_user


@app.get("/users/me/items/")
async def read_own_items(
    current_user: User = Security(get_current_active_user, scopes=["items"]),
):
    return [{"item_id": "Foo", "owner": current_user.username}]


@app.get("/status/")
async def read_system_status(current_user: User = Depends(get_current_user)):
    return {"status": "ok"}

ヒント

可能であれば`Annotated`バージョンを使用することをお勧めします。

from datetime import datetime, timedelta, timezone
from typing import List, Union

import jwt
from fastapi import Depends, FastAPI, HTTPException, Security, status
from fastapi.security import (
    OAuth2PasswordBearer,
    OAuth2PasswordRequestForm,
    SecurityScopes,
)
from jwt.exceptions import InvalidTokenError
from pwdlib import PasswordHash
from pydantic import BaseModel, ValidationError

# to get a string like this run:
# openssl rand -hex 32
SECRET_KEY = "09d25e094faa6ca2556c818166b7a9563b93f7099f6f0f4caa6cf63b88e8d3e7"
ALGORITHM = "HS256"
ACCESS_TOKEN_EXPIRE_MINUTES = 30


fake_users_db = {
    "johndoe": {
        "username": "johndoe",
        "full_name": "John Doe",
        "email": "johndoe@example.com",
        "hashed_password": "$argon2id$v=19$m=65536,t=3,p=4$wagCPXjifgvUFBzq4hqe3w$CYaIb8sB+wtD+Vu/P4uod1+Qof8h+1g7bbDlBID48Rc",
        "disabled": False,
    },
    "alice": {
        "username": "alice",
        "full_name": "Alice Chains",
        "email": "alicechains@example.com",
        "hashed_password": "$argon2id$v=19$m=65536,t=3,p=4$g2/AV1zwopqUntPKJavBFw$BwpRGDCyUHLvHICnwijyX8ROGoiUPwNKZ7915MeYfCE",
        "disabled": True,
    },
}


class Token(BaseModel):
    access_token: str
    token_type: str


class TokenData(BaseModel):
    username: Union[str, None] = None
    scopes: List[str] = []


class User(BaseModel):
    username: str
    email: Union[str, None] = None
    full_name: Union[str, None] = None
    disabled: Union[bool, None] = None


class UserInDB(User):
    hashed_password: str


password_hash = PasswordHash.recommended()

oauth2_scheme = OAuth2PasswordBearer(
    tokenUrl="token",
    scopes={"me": "Read information about the current user.", "items": "Read items."},
)

app = FastAPI()


def verify_password(plain_password, hashed_password):
    return password_hash.verify(plain_password, hashed_password)


def get_password_hash(password):
    return password_hash.hash(password)


def get_user(db, username: str):
    if username in db:
        user_dict = db[username]
        return UserInDB(**user_dict)


def authenticate_user(fake_db, username: str, password: str):
    user = get_user(fake_db, username)
    if not user:
        return False
    if not verify_password(password, user.hashed_password):
        return False
    return user


def create_access_token(data: dict, expires_delta: Union[timedelta, None] = None):
    to_encode = data.copy()
    if expires_delta:
        expire = datetime.now(timezone.utc) + expires_delta
    else:
        expire = datetime.now(timezone.utc) + timedelta(minutes=15)
    to_encode.update({"exp": expire})
    encoded_jwt = jwt.encode(to_encode, SECRET_KEY, algorithm=ALGORITHM)
    return encoded_jwt


async def get_current_user(
    security_scopes: SecurityScopes, token: str = Depends(oauth2_scheme)
):
    if security_scopes.scopes:
        authenticate_value = f'Bearer scope="{security_scopes.scope_str}"'
    else:
        authenticate_value = "Bearer"
    credentials_exception = HTTPException(
        status_code=status.HTTP_401_UNAUTHORIZED,
        detail="Could not validate credentials",
        headers={"WWW-Authenticate": authenticate_value},
    )
    try:
        payload = jwt.decode(token, SECRET_KEY, algorithms=[ALGORITHM])
        username: str = payload.get("sub")
        if username is None:
            raise credentials_exception
        scope: str = payload.get("scope", "")
        token_scopes = scope.split(" ")
        token_data = TokenData(scopes=token_scopes, username=username)
    except (InvalidTokenError, ValidationError):
        raise credentials_exception
    user = get_user(fake_users_db, username=token_data.username)
    if user is None:
        raise credentials_exception
    for scope in security_scopes.scopes:
        if scope not in token_data.scopes:
            raise HTTPException(
                status_code=status.HTTP_401_UNAUTHORIZED,
                detail="Not enough permissions",
                headers={"WWW-Authenticate": authenticate_value},
            )
    return user


async def get_current_active_user(
    current_user: User = Security(get_current_user, scopes=["me"]),
):
    if current_user.disabled:
        raise HTTPException(status_code=400, detail="Inactive user")
    return current_user


@app.post("/token")
async def login_for_access_token(
    form_data: OAuth2PasswordRequestForm = Depends(),
) -> Token:
    user = authenticate_user(fake_users_db, form_data.username, form_data.password)
    if not user:
        raise HTTPException(status_code=400, detail="Incorrect username or password")
    access_token_expires = timedelta(minutes=ACCESS_TOKEN_EXPIRE_MINUTES)
    access_token = create_access_token(
        data={"sub": user.username, "scope": " ".join(form_data.scopes)},
        expires_delta=access_token_expires,
    )
    return Token(access_token=access_token, token_type="bearer")


@app.get("/users/me/", response_model=User)
async def read_users_me(current_user: User = Depends(get_current_active_user)):
    return current_user


@app.get("/users/me/items/")
async def read_own_items(
    current_user: User = Security(get_current_active_user, scopes=["items"]),
):
    return [{"item_id": "Foo", "owner": current_user.username}]


@app.get("/status/")
async def read_system_status(current_user: User = Depends(get_current_user)):
    return {"status": "ok"}

scopesを検証する

次に、この依存関係とすべての依存関係（パス操作を含む）によって要求されるすべてのスコープが、受信したトークンで提供されたスコープに含まれていることを確認します。含まれていない場合は、HTTPExceptionを発生させます。

このために、これらのすべてのスコープをstrのlistとして含むsecurity_scopes.scopesを使用します。

Python 3.10+

from datetime import datetime, timedelta, timezone
from typing import Annotated

import jwt
from fastapi import Depends, FastAPI, HTTPException, Security, status
from fastapi.security import (
    OAuth2PasswordBearer,
    OAuth2PasswordRequestForm,
    SecurityScopes,
)
from jwt.exceptions import InvalidTokenError
from pwdlib import PasswordHash
from pydantic import BaseModel, ValidationError

# to get a string like this run:
# openssl rand -hex 32
SECRET_KEY = "09d25e094faa6ca2556c818166b7a9563b93f7099f6f0f4caa6cf63b88e8d3e7"
ALGORITHM = "HS256"
ACCESS_TOKEN_EXPIRE_MINUTES = 30


fake_users_db = {
    "johndoe": {
        "username": "johndoe",
        "full_name": "John Doe",
        "email": "johndoe@example.com",
        "hashed_password": "$argon2id$v=19$m=65536,t=3,p=4$wagCPXjifgvUFBzq4hqe3w$CYaIb8sB+wtD+Vu/P4uod1+Qof8h+1g7bbDlBID48Rc",
        "disabled": False,
    },
    "alice": {
        "username": "alice",
        "full_name": "Alice Chains",
        "email": "alicechains@example.com",
        "hashed_password": "$argon2id$v=19$m=65536,t=3,p=4$g2/AV1zwopqUntPKJavBFw$BwpRGDCyUHLvHICnwijyX8ROGoiUPwNKZ7915MeYfCE",
        "disabled": True,
    },
}


class Token(BaseModel):
    access_token: str
    token_type: str


class TokenData(BaseModel):
    username: str | None = None
    scopes: list[str] = []


class User(BaseModel):
    username: str
    email: str | None = None
    full_name: str | None = None
    disabled: bool | None = None


class UserInDB(User):
    hashed_password: str


password_hash = PasswordHash.recommended()

oauth2_scheme = OAuth2PasswordBearer(
    tokenUrl="token",
    scopes={"me": "Read information about the current user.", "items": "Read items."},
)

app = FastAPI()


def verify_password(plain_password, hashed_password):
    return password_hash.verify(plain_password, hashed_password)


def get_password_hash(password):
    return password_hash.hash(password)


def get_user(db, username: str):
    if username in db:
        user_dict = db[username]
        return UserInDB(**user_dict)


def authenticate_user(fake_db, username: str, password: str):
    user = get_user(fake_db, username)
    if not user:
        return False
    if not verify_password(password, user.hashed_password):
        return False
    return user


def create_access_token(data: dict, expires_delta: timedelta | None = None):
    to_encode = data.copy()
    if expires_delta:
        expire = datetime.now(timezone.utc) + expires_delta
    else:
        expire = datetime.now(timezone.utc) + timedelta(minutes=15)
    to_encode.update({"exp": expire})
    encoded_jwt = jwt.encode(to_encode, SECRET_KEY, algorithm=ALGORITHM)
    return encoded_jwt


async def get_current_user(
    security_scopes: SecurityScopes, token: Annotated[str, Depends(oauth2_scheme)]
):
    if security_scopes.scopes:
        authenticate_value = f'Bearer scope="{security_scopes.scope_str}"'
    else:
        authenticate_value = "Bearer"
    credentials_exception = HTTPException(
        status_code=status.HTTP_401_UNAUTHORIZED,
        detail="Could not validate credentials",
        headers={"WWW-Authenticate": authenticate_value},
    )
    try:
        payload = jwt.decode(token, SECRET_KEY, algorithms=[ALGORITHM])
        username = payload.get("sub")
        if username is None:
            raise credentials_exception
        scope: str = payload.get("scope", "")
        token_scopes = scope.split(" ")
        token_data = TokenData(scopes=token_scopes, username=username)
    except (InvalidTokenError, ValidationError):
        raise credentials_exception
    user = get_user(fake_users_db, username=token_data.username)
    if user is None:
        raise credentials_exception
    for scope in security_scopes.scopes:
        if scope not in token_data.scopes:
            raise HTTPException(
                status_code=status.HTTP_401_UNAUTHORIZED,
                detail="Not enough permissions",
                headers={"WWW-Authenticate": authenticate_value},
            )
    return user


async def get_current_active_user(
    current_user: Annotated[User, Security(get_current_user, scopes=["me"])],
):
    if current_user.disabled:
        raise HTTPException(status_code=400, detail="Inactive user")
    return current_user


@app.post("/token")
async def login_for_access_token(
    form_data: Annotated[OAuth2PasswordRequestForm, Depends()],
) -> Token:
    user = authenticate_user(fake_users_db, form_data.username, form_data.password)
    if not user:
        raise HTTPException(status_code=400, detail="Incorrect username or password")
    access_token_expires = timedelta(minutes=ACCESS_TOKEN_EXPIRE_MINUTES)
    access_token = create_access_token(
        data={"sub": user.username, "scope": " ".join(form_data.scopes)},
        expires_delta=access_token_expires,
    )
    return Token(access_token=access_token, token_type="bearer")


@app.get("/users/me/", response_model=User)
async def read_users_me(
    current_user: Annotated[User, Depends(get_current_active_user)],
):
    return current_user


@app.get("/users/me/items/")
async def read_own_items(
    current_user: Annotated[User, Security(get_current_active_user, scopes=["items"])],
):
    return [{"item_id": "Foo", "owner": current_user.username}]


@app.get("/status/")
async def read_system_status(current_user: Annotated[User, Depends(get_current_user)]):
    return {"status": "ok"}

🤓 その他のバージョンとバリアント

Python 3.9+Python 3.8+Python 3.10+ - non-AnnotatedPython 3.9+ - 非注釈付きPython 3.8+ - non-Annotated

from datetime import datetime, timedelta, timezone
from typing import Annotated, Union

import jwt
from fastapi import Depends, FastAPI, HTTPException, Security, status
from fastapi.security import (
    OAuth2PasswordBearer,
    OAuth2PasswordRequestForm,
    SecurityScopes,
)
from jwt.exceptions import InvalidTokenError
from pwdlib import PasswordHash
from pydantic import BaseModel, ValidationError

# to get a string like this run:
# openssl rand -hex 32
SECRET_KEY = "09d25e094faa6ca2556c818166b7a9563b93f7099f6f0f4caa6cf63b88e8d3e7"
ALGORITHM = "HS256"
ACCESS_TOKEN_EXPIRE_MINUTES = 30


fake_users_db = {
    "johndoe": {
        "username": "johndoe",
        "full_name": "John Doe",
        "email": "johndoe@example.com",
        "hashed_password": "$argon2id$v=19$m=65536,t=3,p=4$wagCPXjifgvUFBzq4hqe3w$CYaIb8sB+wtD+Vu/P4uod1+Qof8h+1g7bbDlBID48Rc",
        "disabled": False,
    },
    "alice": {
        "username": "alice",
        "full_name": "Alice Chains",
        "email": "alicechains@example.com",
        "hashed_password": "$argon2id$v=19$m=65536,t=3,p=4$g2/AV1zwopqUntPKJavBFw$BwpRGDCyUHLvHICnwijyX8ROGoiUPwNKZ7915MeYfCE",
        "disabled": True,
    },
}


class Token(BaseModel):
    access_token: str
    token_type: str


class TokenData(BaseModel):
    username: Union[str, None] = None
    scopes: list[str] = []


class User(BaseModel):
    username: str
    email: Union[str, None] = None
    full_name: Union[str, None] = None
    disabled: Union[bool, None] = None


class UserInDB(User):
    hashed_password: str


password_hash = PasswordHash.recommended()

oauth2_scheme = OAuth2PasswordBearer(
    tokenUrl="token",
    scopes={"me": "Read information about the current user.", "items": "Read items."},
)

app = FastAPI()


def verify_password(plain_password, hashed_password):
    return password_hash.verify(plain_password, hashed_password)


def get_password_hash(password):
    return password_hash.hash(password)


def get_user(db, username: str):
    if username in db:
        user_dict = db[username]
        return UserInDB(**user_dict)


def authenticate_user(fake_db, username: str, password: str):
    user = get_user(fake_db, username)
    if not user:
        return False
    if not verify_password(password, user.hashed_password):
        return False
    return user


def create_access_token(data: dict, expires_delta: Union[timedelta, None] = None):
    to_encode = data.copy()
    if expires_delta:
        expire = datetime.now(timezone.utc) + expires_delta
    else:
        expire = datetime.now(timezone.utc) + timedelta(minutes=15)
    to_encode.update({"exp": expire})
    encoded_jwt = jwt.encode(to_encode, SECRET_KEY, algorithm=ALGORITHM)
    return encoded_jwt


async def get_current_user(
    security_scopes: SecurityScopes, token: Annotated[str, Depends(oauth2_scheme)]
):
    if security_scopes.scopes:
        authenticate_value = f'Bearer scope="{security_scopes.scope_str}"'
    else:
        authenticate_value = "Bearer"
    credentials_exception = HTTPException(
        status_code=status.HTTP_401_UNAUTHORIZED,
        detail="Could not validate credentials",
        headers={"WWW-Authenticate": authenticate_value},
    )
    try:
        payload = jwt.decode(token, SECRET_KEY, algorithms=[ALGORITHM])
        username = payload.get("sub")
        if username is None:
            raise credentials_exception
        scope: str = payload.get("scope", "")
        token_scopes = scope.split(" ")
        token_data = TokenData(scopes=token_scopes, username=username)
    except (InvalidTokenError, ValidationError):
        raise credentials_exception
    user = get_user(fake_users_db, username=token_data.username)
    if user is None:
        raise credentials_exception
    for scope in security_scopes.scopes:
        if scope not in token_data.scopes:
            raise HTTPException(
                status_code=status.HTTP_401_UNAUTHORIZED,
                detail="Not enough permissions",
                headers={"WWW-Authenticate": authenticate_value},
            )
    return user


async def get_current_active_user(
    current_user: Annotated[User, Security(get_current_user, scopes=["me"])],
):
    if current_user.disabled:
        raise HTTPException(status_code=400, detail="Inactive user")
    return current_user


@app.post("/token")
async def login_for_access_token(
    form_data: Annotated[OAuth2PasswordRequestForm, Depends()],
) -> Token:
    user = authenticate_user(fake_users_db, form_data.username, form_data.password)
    if not user:
        raise HTTPException(status_code=400, detail="Incorrect username or password")
    access_token_expires = timedelta(minutes=ACCESS_TOKEN_EXPIRE_MINUTES)
    access_token = create_access_token(
        data={"sub": user.username, "scope": " ".join(form_data.scopes)},
        expires_delta=access_token_expires,
    )
    return Token(access_token=access_token, token_type="bearer")


@app.get("/users/me/", response_model=User)
async def read_users_me(
    current_user: Annotated[User, Depends(get_current_active_user)],
):
    return current_user


@app.get("/users/me/items/")
async def read_own_items(
    current_user: Annotated[User, Security(get_current_active_user, scopes=["items"])],
):
    return [{"item_id": "Foo", "owner": current_user.username}]


@app.get("/status/")
async def read_system_status(current_user: Annotated[User, Depends(get_current_user)]):
    return {"status": "ok"}

from datetime import datetime, timedelta, timezone
from typing import List, Union

import jwt
from fastapi import Depends, FastAPI, HTTPException, Security, status
from fastapi.security import (
    OAuth2PasswordBearer,
    OAuth2PasswordRequestForm,
    SecurityScopes,
)
from jwt.exceptions import InvalidTokenError
from pwdlib import PasswordHash
from pydantic import BaseModel, ValidationError
from typing_extensions import Annotated

# to get a string like this run:
# openssl rand -hex 32
SECRET_KEY = "09d25e094faa6ca2556c818166b7a9563b93f7099f6f0f4caa6cf63b88e8d3e7"
ALGORITHM = "HS256"
ACCESS_TOKEN_EXPIRE_MINUTES = 30


fake_users_db = {
    "johndoe": {
        "username": "johndoe",
        "full_name": "John Doe",
        "email": "johndoe@example.com",
        "hashed_password": "$argon2id$v=19$m=65536,t=3,p=4$wagCPXjifgvUFBzq4hqe3w$CYaIb8sB+wtD+Vu/P4uod1+Qof8h+1g7bbDlBID48Rc",
        "disabled": False,
    },
    "alice": {
        "username": "alice",
        "full_name": "Alice Chains",
        "email": "alicechains@example.com",
        "hashed_password": "$argon2id$v=19$m=65536,t=3,p=4$g2/AV1zwopqUntPKJavBFw$BwpRGDCyUHLvHICnwijyX8ROGoiUPwNKZ7915MeYfCE",
        "disabled": True,
    },
}


class Token(BaseModel):
    access_token: str
    token_type: str


class TokenData(BaseModel):
    username: Union[str, None] = None
    scopes: List[str] = []


class User(BaseModel):
    username: str
    email: Union[str, None] = None
    full_name: Union[str, None] = None
    disabled: Union[bool, None] = None


class UserInDB(User):
    hashed_password: str


password_hash = PasswordHash.recommended()

oauth2_scheme = OAuth2PasswordBearer(
    tokenUrl="token",
    scopes={"me": "Read information about the current user.", "items": "Read items."},
)

app = FastAPI()


def verify_password(plain_password, hashed_password):
    return password_hash.verify(plain_password, hashed_password)


def get_password_hash(password):
    return password_hash.hash(password)


def get_user(db, username: str):
    if username in db:
        user_dict = db[username]
        return UserInDB(**user_dict)


def authenticate_user(fake_db, username: str, password: str):
    user = get_user(fake_db, username)
    if not user:
        return False
    if not verify_password(password, user.hashed_password):
        return False
    return user


def create_access_token(data: dict, expires_delta: Union[timedelta, None] = None):
    to_encode = data.copy()
    if expires_delta:
        expire = datetime.now(timezone.utc) + expires_delta
    else:
        expire = datetime.now(timezone.utc) + timedelta(minutes=15)
    to_encode.update({"exp": expire})
    encoded_jwt = jwt.encode(to_encode, SECRET_KEY, algorithm=ALGORITHM)
    return encoded_jwt


async def get_current_user(
    security_scopes: SecurityScopes, token: Annotated[str, Depends(oauth2_scheme)]
):
    if security_scopes.scopes:
        authenticate_value = f'Bearer scope="{security_scopes.scope_str}"'
    else:
        authenticate_value = "Bearer"
    credentials_exception = HTTPException(
        status_code=status.HTTP_401_UNAUTHORIZED,
        detail="Could not validate credentials",
        headers={"WWW-Authenticate": authenticate_value},
    )
    try:
        payload = jwt.decode(token, SECRET_KEY, algorithms=[ALGORITHM])
        username = payload.get("sub")
        if username is None:
            raise credentials_exception
        scope: str = payload.get("scope", "")
        token_scopes = scope.split(" ")
        token_data = TokenData(scopes=token_scopes, username=username)
    except (InvalidTokenError, ValidationError):
        raise credentials_exception
    user = get_user(fake_users_db, username=token_data.username)
    if user is None:
        raise credentials_exception
    for scope in security_scopes.scopes:
        if scope not in token_data.scopes:
            raise HTTPException(
                status_code=status.HTTP_401_UNAUTHORIZED,
                detail="Not enough permissions",
                headers={"WWW-Authenticate": authenticate_value},
            )
    return user


async def get_current_active_user(
    current_user: Annotated[User, Security(get_current_user, scopes=["me"])],
):
    if current_user.disabled:
        raise HTTPException(status_code=400, detail="Inactive user")
    return current_user


@app.post("/token")
async def login_for_access_token(
    form_data: Annotated[OAuth2PasswordRequestForm, Depends()],
) -> Token:
    user = authenticate_user(fake_users_db, form_data.username, form_data.password)
    if not user:
        raise HTTPException(status_code=400, detail="Incorrect username or password")
    access_token_expires = timedelta(minutes=ACCESS_TOKEN_EXPIRE_MINUTES)
    access_token = create_access_token(
        data={"sub": user.username, "scope": " ".join(form_data.scopes)},
        expires_delta=access_token_expires,
    )
    return Token(access_token=access_token, token_type="bearer")


@app.get("/users/me/", response_model=User)
async def read_users_me(
    current_user: Annotated[User, Depends(get_current_active_user)],
):
    return current_user


@app.get("/users/me/items/")
async def read_own_items(
    current_user: Annotated[User, Security(get_current_active_user, scopes=["items"])],
):
    return [{"item_id": "Foo", "owner": current_user.username}]


@app.get("/status/")
async def read_system_status(current_user: Annotated[User, Depends(get_current_user)]):
    return {"status": "ok"}

ヒント

可能であれば`Annotated`バージョンを使用することをお勧めします。

from datetime import datetime, timedelta, timezone

import jwt
from fastapi import Depends, FastAPI, HTTPException, Security, status
from fastapi.security import (
    OAuth2PasswordBearer,
    OAuth2PasswordRequestForm,
    SecurityScopes,
)
from jwt.exceptions import InvalidTokenError
from pwdlib import PasswordHash
from pydantic import BaseModel, ValidationError

# to get a string like this run:
# openssl rand -hex 32
SECRET_KEY = "09d25e094faa6ca2556c818166b7a9563b93f7099f6f0f4caa6cf63b88e8d3e7"
ALGORITHM = "HS256"
ACCESS_TOKEN_EXPIRE_MINUTES = 30


fake_users_db = {
    "johndoe": {
        "username": "johndoe",
        "full_name": "John Doe",
        "email": "johndoe@example.com",
        "hashed_password": "$argon2id$v=19$m=65536,t=3,p=4$wagCPXjifgvUFBzq4hqe3w$CYaIb8sB+wtD+Vu/P4uod1+Qof8h+1g7bbDlBID48Rc",
        "disabled": False,
    },
    "alice": {
        "username": "alice",
        "full_name": "Alice Chains",
        "email": "alicechains@example.com",
        "hashed_password": "$argon2id$v=19$m=65536,t=3,p=4$g2/AV1zwopqUntPKJavBFw$BwpRGDCyUHLvHICnwijyX8ROGoiUPwNKZ7915MeYfCE",
        "disabled": True,
    },
}


class Token(BaseModel):
    access_token: str
    token_type: str


class TokenData(BaseModel):
    username: str | None = None
    scopes: list[str] = []


class User(BaseModel):
    username: str
    email: str | None = None
    full_name: str | None = None
    disabled: bool | None = None


class UserInDB(User):
    hashed_password: str


password_hash = PasswordHash.recommended()

oauth2_scheme = OAuth2PasswordBearer(
    tokenUrl="token",
    scopes={"me": "Read information about the current user.", "items": "Read items."},
)

app = FastAPI()


def verify_password(plain_password, hashed_password):
    return password_hash.verify(plain_password, hashed_password)


def get_password_hash(password):
    return password_hash.hash(password)


def get_user(db, username: str):
    if username in db:
        user_dict = db[username]
        return UserInDB(**user_dict)


def authenticate_user(fake_db, username: str, password: str):
    user = get_user(fake_db, username)
    if not user:
        return False
    if not verify_password(password, user.hashed_password):
        return False
    return user


def create_access_token(data: dict, expires_delta: timedelta | None = None):
    to_encode = data.copy()
    if expires_delta:
        expire = datetime.now(timezone.utc) + expires_delta
    else:
        expire = datetime.now(timezone.utc) + timedelta(minutes=15)
    to_encode.update({"exp": expire})
    encoded_jwt = jwt.encode(to_encode, SECRET_KEY, algorithm=ALGORITHM)
    return encoded_jwt


async def get_current_user(
    security_scopes: SecurityScopes, token: str = Depends(oauth2_scheme)
):
    if security_scopes.scopes:
        authenticate_value = f'Bearer scope="{security_scopes.scope_str}"'
    else:
        authenticate_value = "Bearer"
    credentials_exception = HTTPException(
        status_code=status.HTTP_401_UNAUTHORIZED,
        detail="Could not validate credentials",
        headers={"WWW-Authenticate": authenticate_value},
    )
    try:
        payload = jwt.decode(token, SECRET_KEY, algorithms=[ALGORITHM])
        username: str = payload.get("sub")
        if username is None:
            raise credentials_exception
        scope: str = payload.get("scope", "")
        token_scopes = scope.split(" ")
        token_data = TokenData(scopes=token_scopes, username=username)
    except (InvalidTokenError, ValidationError):
        raise credentials_exception
    user = get_user(fake_users_db, username=token_data.username)
    if user is None:
        raise credentials_exception
    for scope in security_scopes.scopes:
        if scope not in token_data.scopes:
            raise HTTPException(
                status_code=status.HTTP_401_UNAUTHORIZED,
                detail="Not enough permissions",
                headers={"WWW-Authenticate": authenticate_value},
            )
    return user


async def get_current_active_user(
    current_user: User = Security(get_current_user, scopes=["me"]),
):
    if current_user.disabled:
        raise HTTPException(status_code=400, detail="Inactive user")
    return current_user


@app.post("/token")
async def login_for_access_token(
    form_data: OAuth2PasswordRequestForm = Depends(),
) -> Token:
    user = authenticate_user(fake_users_db, form_data.username, form_data.password)
    if not user:
        raise HTTPException(status_code=400, detail="Incorrect username or password")
    access_token_expires = timedelta(minutes=ACCESS_TOKEN_EXPIRE_MINUTES)
    access_token = create_access_token(
        data={"sub": user.username, "scope": " ".join(form_data.scopes)},
        expires_delta=access_token_expires,
    )
    return Token(access_token=access_token, token_type="bearer")


@app.get("/users/me/", response_model=User)
async def read_users_me(current_user: User = Depends(get_current_active_user)):
    return current_user


@app.get("/users/me/items/")
async def read_own_items(
    current_user: User = Security(get_current_active_user, scopes=["items"]),
):
    return [{"item_id": "Foo", "owner": current_user.username}]


@app.get("/status/")
async def read_system_status(current_user: User = Depends(get_current_user)):
    return {"status": "ok"}

ヒント

可能であれば`Annotated`バージョンを使用することをお勧めします。

from datetime import datetime, timedelta, timezone
from typing import Union

import jwt
from fastapi import Depends, FastAPI, HTTPException, Security, status
from fastapi.security import (
    OAuth2PasswordBearer,
    OAuth2PasswordRequestForm,
    SecurityScopes,
)
from jwt.exceptions import InvalidTokenError
from pwdlib import PasswordHash
from pydantic import BaseModel, ValidationError

# to get a string like this run:
# openssl rand -hex 32
SECRET_KEY = "09d25e094faa6ca2556c818166b7a9563b93f7099f6f0f4caa6cf63b88e8d3e7"
ALGORITHM = "HS256"
ACCESS_TOKEN_EXPIRE_MINUTES = 30


fake_users_db = {
    "johndoe": {
        "username": "johndoe",
        "full_name": "John Doe",
        "email": "johndoe@example.com",
        "hashed_password": "$argon2id$v=19$m=65536,t=3,p=4$wagCPXjifgvUFBzq4hqe3w$CYaIb8sB+wtD+Vu/P4uod1+Qof8h+1g7bbDlBID48Rc",
        "disabled": False,
    },
    "alice": {
        "username": "alice",
        "full_name": "Alice Chains",
        "email": "alicechains@example.com",
        "hashed_password": "$argon2id$v=19$m=65536,t=3,p=4$g2/AV1zwopqUntPKJavBFw$BwpRGDCyUHLvHICnwijyX8ROGoiUPwNKZ7915MeYfCE",
        "disabled": True,
    },
}


class Token(BaseModel):
    access_token: str
    token_type: str


class TokenData(BaseModel):
    username: Union[str, None] = None
    scopes: list[str] = []


class User(BaseModel):
    username: str
    email: Union[str, None] = None
    full_name: Union[str, None] = None
    disabled: Union[bool, None] = None


class UserInDB(User):
    hashed_password: str


password_hash = PasswordHash.recommended()

oauth2_scheme = OAuth2PasswordBearer(
    tokenUrl="token",
    scopes={"me": "Read information about the current user.", "items": "Read items."},
)

app = FastAPI()


def verify_password(plain_password, hashed_password):
    return password_hash.verify(plain_password, hashed_password)


def get_password_hash(password):
    return password_hash.hash(password)


def get_user(db, username: str):
    if username in db:
        user_dict = db[username]
        return UserInDB(**user_dict)


def authenticate_user(fake_db, username: str, password: str):
    user = get_user(fake_db, username)
    if not user:
        return False
    if not verify_password(password, user.hashed_password):
        return False
    return user


def create_access_token(data: dict, expires_delta: Union[timedelta, None] = None):
    to_encode = data.copy()
    if expires_delta:
        expire = datetime.now(timezone.utc) + expires_delta
    else:
        expire = datetime.now(timezone.utc) + timedelta(minutes=15)
    to_encode.update({"exp": expire})
    encoded_jwt = jwt.encode(to_encode, SECRET_KEY, algorithm=ALGORITHM)
    return encoded_jwt


async def get_current_user(
    security_scopes: SecurityScopes, token: str = Depends(oauth2_scheme)
):
    if security_scopes.scopes:
        authenticate_value = f'Bearer scope="{security_scopes.scope_str}"'
    else:
        authenticate_value = "Bearer"
    credentials_exception = HTTPException(
        status_code=status.HTTP_401_UNAUTHORIZED,
        detail="Could not validate credentials",
        headers={"WWW-Authenticate": authenticate_value},
    )
    try:
        payload = jwt.decode(token, SECRET_KEY, algorithms=[ALGORITHM])
        username: str = payload.get("sub")
        if username is None:
            raise credentials_exception
        scope: str = payload.get("scope", "")
        token_scopes = scope.split(" ")
        token_data = TokenData(scopes=token_scopes, username=username)
    except (InvalidTokenError, ValidationError):
        raise credentials_exception
    user = get_user(fake_users_db, username=token_data.username)
    if user is None:
        raise credentials_exception
    for scope in security_scopes.scopes:
        if scope not in token_data.scopes:
            raise HTTPException(
                status_code=status.HTTP_401_UNAUTHORIZED,
                detail="Not enough permissions",
                headers={"WWW-Authenticate": authenticate_value},
            )
    return user


async def get_current_active_user(
    current_user: User = Security(get_current_user, scopes=["me"]),
):
    if current_user.disabled:
        raise HTTPException(status_code=400, detail="Inactive user")
    return current_user


@app.post("/token")
async def login_for_access_token(
    form_data: OAuth2PasswordRequestForm = Depends(),
) -> Token:
    user = authenticate_user(fake_users_db, form_data.username, form_data.password)
    if not user:
        raise HTTPException(status_code=400, detail="Incorrect username or password")
    access_token_expires = timedelta(minutes=ACCESS_TOKEN_EXPIRE_MINUTES)
    access_token = create_access_token(
        data={"sub": user.username, "scope": " ".join(form_data.scopes)},
        expires_delta=access_token_expires,
    )
    return Token(access_token=access_token, token_type="bearer")


@app.get("/users/me/", response_model=User)
async def read_users_me(current_user: User = Depends(get_current_active_user)):
    return current_user


@app.get("/users/me/items/")
async def read_own_items(
    current_user: User = Security(get_current_active_user, scopes=["items"]),
):
    return [{"item_id": "Foo", "owner": current_user.username}]


@app.get("/status/")
async def read_system_status(current_user: User = Depends(get_current_user)):
    return {"status": "ok"}

ヒント

可能であれば`Annotated`バージョンを使用することをお勧めします。

from datetime import datetime, timedelta, timezone
from typing import List, Union

import jwt
from fastapi import Depends, FastAPI, HTTPException, Security, status
from fastapi.security import (
    OAuth2PasswordBearer,
    OAuth2PasswordRequestForm,
    SecurityScopes,
)
from jwt.exceptions import InvalidTokenError
from pwdlib import PasswordHash
from pydantic import BaseModel, ValidationError

# to get a string like this run:
# openssl rand -hex 32
SECRET_KEY = "09d25e094faa6ca2556c818166b7a9563b93f7099f6f0f4caa6cf63b88e8d3e7"
ALGORITHM = "HS256"
ACCESS_TOKEN_EXPIRE_MINUTES = 30


fake_users_db = {
    "johndoe": {
        "username": "johndoe",
        "full_name": "John Doe",
        "email": "johndoe@example.com",
        "hashed_password": "$argon2id$v=19$m=65536,t=3,p=4$wagCPXjifgvUFBzq4hqe3w$CYaIb8sB+wtD+Vu/P4uod1+Qof8h+1g7bbDlBID48Rc",
        "disabled": False,
    },
    "alice": {
        "username": "alice",
        "full_name": "Alice Chains",
        "email": "alicechains@example.com",
        "hashed_password": "$argon2id$v=19$m=65536,t=3,p=4$g2/AV1zwopqUntPKJavBFw$BwpRGDCyUHLvHICnwijyX8ROGoiUPwNKZ7915MeYfCE",
        "disabled": True,
    },
}


class Token(BaseModel):
    access_token: str
    token_type: str


class TokenData(BaseModel):
    username: Union[str, None] = None
    scopes: List[str] = []


class User(BaseModel):
    username: str
    email: Union[str, None] = None
    full_name: Union[str, None] = None
    disabled: Union[bool, None] = None


class UserInDB(User):
    hashed_password: str


password_hash = PasswordHash.recommended()

oauth2_scheme = OAuth2PasswordBearer(
    tokenUrl="token",
    scopes={"me": "Read information about the current user.", "items": "Read items."},
)

app = FastAPI()


def verify_password(plain_password, hashed_password):
    return password_hash.verify(plain_password, hashed_password)


def get_password_hash(password):
    return password_hash.hash(password)


def get_user(db, username: str):
    if username in db:
        user_dict = db[username]
        return UserInDB(**user_dict)


def authenticate_user(fake_db, username: str, password: str):
    user = get_user(fake_db, username)
    if not user:
        return False
    if not verify_password(password, user.hashed_password):
        return False
    return user


def create_access_token(data: dict, expires_delta: Union[timedelta, None] = None):
    to_encode = data.copy()
    if expires_delta:
        expire = datetime.now(timezone.utc) + expires_delta
    else:
        expire = datetime.now(timezone.utc) + timedelta(minutes=15)
    to_encode.update({"exp": expire})
    encoded_jwt = jwt.encode(to_encode, SECRET_KEY, algorithm=ALGORITHM)
    return encoded_jwt


async def get_current_user(
    security_scopes: SecurityScopes, token: str = Depends(oauth2_scheme)
):
    if security_scopes.scopes:
        authenticate_value = f'Bearer scope="{security_scopes.scope_str}"'
    else:
        authenticate_value = "Bearer"
    credentials_exception = HTTPException(
        status_code=status.HTTP_401_UNAUTHORIZED,
        detail="Could not validate credentials",
        headers={"WWW-Authenticate": authenticate_value},
    )
    try:
        payload = jwt.decode(token, SECRET_KEY, algorithms=[ALGORITHM])
        username: str = payload.get("sub")
        if username is None:
            raise credentials_exception
        scope: str = payload.get("scope", "")
        token_scopes = scope.split(" ")
        token_data = TokenData(scopes=token_scopes, username=username)
    except (InvalidTokenError, ValidationError):
        raise credentials_exception
    user = get_user(fake_users_db, username=token_data.username)
    if user is None:
        raise credentials_exception
    for scope in security_scopes.scopes:
        if scope not in token_data.scopes:
            raise HTTPException(
                status_code=status.HTTP_401_UNAUTHORIZED,
                detail="Not enough permissions",
                headers={"WWW-Authenticate": authenticate_value},
            )
    return user


async def get_current_active_user(
    current_user: User = Security(get_current_user, scopes=["me"]),
):
    if current_user.disabled:
        raise HTTPException(status_code=400, detail="Inactive user")
    return current_user


@app.post("/token")
async def login_for_access_token(
    form_data: OAuth2PasswordRequestForm = Depends(),
) -> Token:
    user = authenticate_user(fake_users_db, form_data.username, form_data.password)
    if not user:
        raise HTTPException(status_code=400, detail="Incorrect username or password")
    access_token_expires = timedelta(minutes=ACCESS_TOKEN_EXPIRE_MINUTES)
    access_token = create_access_token(
        data={"sub": user.username, "scope": " ".join(form_data.scopes)},
        expires_delta=access_token_expires,
    )
    return Token(access_token=access_token, token_type="bearer")


@app.get("/users/me/", response_model=User)
async def read_users_me(current_user: User = Depends(get_current_active_user)):
    return current_user


@app.get("/users/me/items/")
async def read_own_items(
    current_user: User = Security(get_current_active_user, scopes=["items"]),
):
    return [{"item_id": "Foo", "owner": current_user.username}]


@app.get("/status/")
async def read_system_status(current_user: User = Depends(get_current_user)):
    return {"status": "ok"}

依存関係ツリーとスコープ

この依存関係ツリーとスコープをもう一度見てみましょう。

get_current_active_user依存関係がget_current_userをサブ依存関係として持つため、get_current_active_userで宣言されたスコープ"me"は、get_current_userに渡される必須スコープのリストsecurity_scopes.scopesに含まれます。

パス操作自体もスコープ"items"を宣言しているため、これもget_current_userに渡されるsecurity_scopes.scopesのリストに含まれます。

依存関係とスコープの階層は次のようになります。

• パス操作read_own_itemsは、
  • 依存関係を持つ必須スコープ["items"]
  • get_current_active_user:
    • 依存関数get_current_active_userは、
      • 依存関係を持つ必須スコープ["me"]
      • get_current_user:
        • 依存関数get_current_userは、
          • それ自体はスコープを必要としません。
          • oauth2_schemeを使用する依存関係。
          • SecurityScopes型のsecurity_scopesパラメータ
            • このsecurity_scopesパラメータには、上記のすべての宣言されたスコープを含むlistであるscopesプロパティがあります。したがって、
              • パス操作read_own_itemsの場合、security_scopes.scopesには["me", "items"]が含まれます。
              • パス操作read_users_meの場合、security_scopes.scopesには["me"]が含まれます。これは、依存関係get_current_active_userで宣言されているためです。
              • パス操作read_system_statusの場合、security_scopes.scopesには[]（何もなし）が含まれます。これは、scopesを持つSecurityを宣言しておらず、その依存関係であるget_current_userもscopesを宣言していないためです。

ヒント

ここで重要で「魔法のような」ことは、get_current_userが、各パス操作ごとに異なるscopesリストをチェックすることです。

これはすべて、特定のパス操作の依存関係ツリーにおける各パス操作と各依存関係で宣言されたscopesに依存します。

SecurityScopesの詳細

SecurityScopesは、どの時点でも複数の場所で使用でき、「ルート」の依存関係である必要はありません。

それは常に、現在のSecurity依存関係と、その特定のパス操作とその特定の依存関係ツリーのすべての依存関係で宣言されたセキュリティスコープを持ちます。

SecurityScopesは依存関係によって宣言されたすべてのスコープを持つため、中央の依存関数でトークンが必要なスコープを持っていることを検証するために使用し、異なるパス操作で異なるスコープ要件を宣言することができます。

それらは各パス操作ごとに個別にチェックされます。

確認

APIドキュメントを開くと、認証して許可するスコープを指定できます。

スコープを選択しない場合、「認証済み」になりますが、/users/me/または/users/me/items/にアクセスしようとすると、十分な権限がないというエラーが表示されます。/status/には引き続きアクセスできます。

スコープmeを選択してもスコープitemsを選択しない場合、/users/me/にはアクセスできますが、/users/me/items/にはアクセスできません。

これは、ユーザーがアプリケーションに与えたパーミッションの数に応じて、ユーザーから提供されたトークンでこれらのパス操作のいずれかにアクセスしようとしたサードパーティアプリケーションに起こることです。

サードパーティ統合について

この例では、OAuth2の「パスワード」フローを使用しています。

これは、独自のアプリケーションにログインする場合、おそらく独自のフロントエンドを使用する場合に適しています。

なぜなら、私たちはそれを制御しているため、usernameとpasswordを受け取ることを信頼できるからです。

しかし、他の人が接続するOAuth2アプリケーションを構築している場合（つまり、Facebook、Google、GitHubなどと同等の認証プロバイダーを構築している場合）、他のフローのいずれかを使用する必要があります。

最も一般的なのは暗黙的フローです。

最も安全なのはコードフローですが、より多くの手順が必要なため、実装がより複雑です。より複雑であるため、多くのプロバイダーは最終的に暗黙的フローを推奨しています。

Note

各認証プロバイダーが、そのブランドの一部とするために、フローに異なる名前を付けるのが一般的です。

しかし、最終的には、同じOAuth2標準を実装しています。

FastAPIには、これらすべてのOAuth2認証フローのためのユーティリティがfastapi.security.oauth2に含まれています。

デコレータのdependenciesにおけるSecurity

デコレータのdependenciesパラメータでDependsのlistを定義できるのと同様に（パス操作デコレータの依存関係で説明されています）、そこでもscopesとともにSecurityを使用できます。