linklogger/app/util/authentication.py

128 lines
3.6 KiB
Python

import random
import bcrypt
from fastapi import Depends, HTTPException, status, Request, Cookie
from fastapi.security import OAuth2PasswordBearer
from fastapi.responses import RedirectResponse
from jwt.exceptions import InvalidTokenError
from datetime import datetime, timedelta
from typing import Annotated, Optional
import jwt
from app.util.db_dependency import get_db
from sqlalchemy.orm import Session
from app.schemas.auth_schemas import *
from models import User as UserModel
secret_key = random.randbytes(32)
algorithm = "HS256"
oauth2_scheme = OAuth2PasswordBearer(tokenUrl="api/auth/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(UserModel).filter(UserModel.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)
if not user:
return False
if not verify_password(password, user.hashed_password):
print("WHY")
return False
return user
def create_access_token(data: dict, expires_delta: timedelta):
"""
Return an encoded JWT token with the given data
"""
to_encode = data.copy()
expire = datetime.utcnow() + expires_delta
to_encode.update({"exp": expire})
encoded_jwt = jwt.encode(to_encode, secret_key, algorithm=algorithm)
return encoded_jwt
# Backwards kind of way to get refresh token support
# `refresh_get_current_user` is only called from /refresh
# and alerts `get_current_user` that it should expect a refresh token
async def refresh_get_current_user(
token: Annotated[str, Depends(oauth2_scheme)],
db=Depends(get_db),
):
return await get_current_user(token, is_refresh=True, db=db)
def process_refresh_token(token: str, db: Session):
return False
async def get_current_user(
request: Request,
db=Depends(get_db),
):
"""
Return the current user based on the token
OR on error -
If is_ui=True, the request is from a UI page and we should redirect to login
Otherwise, the request is from an API and we should return a 401
"""
def raise_unauthorized():
raise HTTPException(
status_code=status.HTTP_401_UNAUTHORIZED,
detail="Could not validate credentials",
headers={"WWW-Authenticate": "Bearer"},
)
# If the request is from /api/auth/refresh, it is a request to get
# a new access token using a refresh token
if request.url.path == "/api/auth/refresh":
token = request.cookies.get("refresh_token")
user = process_refresh_token(token, db)
if user is None:
raise_unauthorized()
else:
token = request.cookies.get("access_token")
try:
payload = jwt.decode(token, secret_key, algorithms=[algorithm])
id: int = payload.get("sub")
username: str = payload.get("username")
refresh: bool = payload.get("refresh")
if not id or not username:
return raise_unauthorized()
# Make sure that a refresh token was not passed to any other endpoint
if refresh and not is_refresh:
return raise_unauthorized()
except InvalidTokenError:
return raise_unauthorized()
user = get_user(db, username)
if user is None:
return raise_unauthorized()
return user