working on authorization

.gitignore

 __pycache__/
-.env/
+.venv/

fastapi/auth.py

+# This is the file where authentication and authorization is implemented
+# This file is imported in main.py and used as middleware
+#
+
+from datetime import datetime, timedelta, timezone
+
+from requests import Session
+from fastapi import HTTPException, Depends
+from fastapi.security import OAuth2PasswordBearer, OAuth2PasswordRequestForm
+import jwt
+from jwt.exceptions import InvalidTokenError
+from passlib.context import CryptContext
+from pydantic import BaseModel
+
+from user.schemas import UserBase
+from user.crud import get_user_by_email
+
+#
+# This is the secret key used to hash the password
+# to get a string like this run:
+# openssl rand -hex 32
+#   
+SECRET_KEY = ""
+
+# This is the password hashing algorithm
+ALGORITHM = "HS256"
+
+# This is the expiration time of the token in minutes
+ACCESS_TOKEN_EXPIRE_MINUTES = 30
+
+#
+# DTOs for token and credentials
+#
+
+class Token(BaseModel):
+    access_token: str
+    token_type: str
+
+class TokenData(BaseModel):
+    username: str
+    role: str
+
+class UserCredentials(BaseModel):
+    email: str
+    password: str
+
+# Password hashing
+pwd_context = CryptContext(schemes=["bcrypt"], deprecated="auto")
+
+def verify_password(plain_password, hashed_password):
+    return pwd_context.verify(plain_password, hashed_password)
+
+def get_password_hash(password):
+    return pwd_context.hash(password)
+
+# Token creation
+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
+
+#
+# Authentication
+#
+def authenticate_user(db: Session, email: str, password: str):
+    user = get_user_by_email(db, email)
+    if not user:
+        return False
+    if not verify_password(password, user.password):
+        return False
+    return user
+
+def login_user(db, email: str, password: str):
+    user = authenticate_user(db, email, 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.email, "role": user.role, "id": user.id},
+        expires_delta=access_token_expires
+    )
+    return Token(access_token=access_token, token_type="bearer")

fastapi/main.py

@@ -91,3 +91,12 @@ def update_loan(user_id: int, book_id: int, start_date: date, loan: loan_schemas
 @app.delete("/loan/{user_id}/{book_id}/{start_date}")
 def delete_loan(user_id: int, book_id: int, start_date: date, db: Session = Depends(get_db)):
     return loan_crud.delete_loan(db, user_id, book_id, start_date)
+
+# Authentication
+from auth import login_user, Token
+from fastapi.security import OAuth2PasswordRequestForm  
+
+@app.post("/login", response_model=Token)
+def login(form_data: OAuth2PasswordRequestForm = Depends(), db: Session = Depends(get_db)):
+    return login_user(db, form_data.username, form_data.password)
+

fastapi/requirements.txt

+fastapi[standard]
+sqlalchemy
+pymysql
+passlib
+pyjwt
+requests

fastapi/user/crud.py

@@ -2,7 +2,7 @@ from sqlalchemy.orm import Session
 from fastapi import HTTPException
 from passlib.context import CryptContext
 from .models import UserDB
-from .schemas import UserCreate, User
+from .schemas import UserCreate
 
 pwd_context = CryptContext(schemes=["bcrypt"], deprecated="auto")
 
@@ -35,6 +35,10 @@ def get_user(db: Session, user_id: int):
         raise HTTPException(status_code=404, detail="User not found")
     return db_user
 
+def get_user_by_email(db: Session, email: str):
+    db_user = db.query(UserDB).filter(UserDB.email == email).first()
+    return db_user
+
 def update_user(db: Session, user_id: int, user: UserCreate):
     db_user = db.query(UserDB).filter(UserDB.id == user_id).first()
     if db_user is None: