First commit.

Signed-off-by: Chen Xiao <abigwc@gmail.com>

server/auth.py

@@ -0,0 +1,55 @@
+from datetime import datetime, timedelta
+from typing import Optional
+from jose import JWTError, jwt
+from passlib.context import CryptContext
+from fastapi import HTTPException, Security, Depends
+from fastapi.security import HTTPBearer, HTTPAuthorizationCredentials
+import db
+
+SECRET_KEY = "your-secret-key-change-in-production"
+ALGORITHM = "HS256"
+ACCESS_TOKEN_EXPIRE_MINUTES = 60 * 24
+
+pwd_context = CryptContext(schemes=["bcrypt"], deprecated="auto")
+security = HTTPBearer()
+optional_security = HTTPBearer(auto_error=False)
+
+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)
+
+def create_access_token(data: dict):
+    to_encode = data.copy()
+    expire = datetime.utcnow() + timedelta(minutes=ACCESS_TOKEN_EXPIRE_MINUTES)
+    to_encode.update({"exp": expire})
+    encoded_jwt = jwt.encode(to_encode, SECRET_KEY, algorithm=ALGORITHM)
+    return encoded_jwt
+
+def get_current_user(credentials: HTTPAuthorizationCredentials = Depends(security)):
+    token = credentials.credentials
+    try:
+        payload = jwt.decode(token, SECRET_KEY, algorithms=[ALGORITHM])
+        user_id: int = payload.get("id")
+        if user_id is None:
+            raise HTTPException(status_code=401, detail="无效的认证信息")
+    except JWTError:
+        raise HTTPException(status_code=403, detail="登录已过期，请重新登录")
+    
+    user = db.get_user_by_id(user_id)
+    if user is None:
+        raise HTTPException(status_code=404, detail="用户不存在")
+    return user
+
+def get_optional_user(credentials: Optional[HTTPAuthorizationCredentials] = Depends(optional_security)):
+    if not credentials:
+        return None
+    try:
+        payload = jwt.decode(credentials.credentials, SECRET_KEY, algorithms=[ALGORITHM])
+        user_id = payload.get("id")
+        if user_id:
+            return db.get_user_by_id(user_id)
+    except JWTError:
+        return None
+    return None