linklogger/api/util/authentication.py

89 lines
2.5 KiB
Python

import random
import bcrypt
from fastapi import Depends, HTTPException, status
from fastapi.security import OAuth2PasswordBearer
from jwt.exceptions import InvalidTokenError
from datetime import datetime, timedelta
from typing import Annotated
import jwt
from api.util.db_dependency import get_db
from api.schemas.auth_schemas import *
from models import User as UserDB
secret_key = random.randbytes(32)
algorithm = "HS256"
oauth2_scheme = OAuth2PasswordBearer(tokenUrl="token")
"""
Helper functions for authentication
"""
def verify_password(plain_password, hashed_password):
return bcrypt.checkpw(
plain_password.encode("utf-8"), hashed_password.encode("utf-8")
)
def get_user(db, username: str):
"""
Get the user object from the database
"""
user = db.query(UserDB).filter(UserDB.username == username).first()
if user:
return UserInDB(**user.__dict__)
def authenticate_user(db, username: str, password: str):
"""
Determine if the correct username and password were provided
If so, return the user object
"""
user = get_user(db, username)
print(user)
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):
"""
Return an encoded JWT token with the given data
"""
to_encode = data.copy()
if expires_delta:
expire = datetime.utcnow() + expires_delta
else:
expire = datetime.utcnow() + 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(
token: Annotated[str, Depends(oauth2_scheme)], db=Depends(get_db)
):
"""
Return the current user based on the token, or raise a 401 error
"""
credentials_exception = HTTPException(
status_code=status.HTTP_401_UNAUTHORIZED,
detail="Could not validate credentials",
headers={"WWW-Authenticate": "Bearer"},
)
try:
payload = jwt.decode(token, secret_key, algorithms=[algorithm])
username: str = payload.get("sub")
if username is None:
raise credentials_exception
token_data = TokenData(username=username)
except InvalidTokenError:
raise credentials_exception
user = get_user(db, username=token_data.username)
if user is None:
raise credentials_exception
return user