hoàn thành phần Authentication

backend/app/security.py

@@ -0,0 +1,43 @@
+from datetime import datetime, timedelta, timezone
+import os
+
+from jose import JWTError, jwt
+from passlib.context import CryptContext
+
+# ── Config (override via environment variables) ───────────────────────────────
+SECRET_KEY: str = os.environ["JWT_SECRET_KEY"]          # must be set — no default
+ALGORITHM: str = os.getenv("JWT_ALGORITHM", "HS256")
+ACCESS_TOKEN_EXPIRE_MINUTES: int = int(
+    os.getenv("ACCESS_TOKEN_EXPIRE_MINUTES", "60")
+)
+
+# ── Password hashing ──────────────────────────────────────────────────────────
+_pwd_context = CryptContext(schemes=["bcrypt"], deprecated="auto")
+
+
+def hash_password(plain: str) -> str:
+    return _pwd_context.hash(plain)
+
+
+def verify_password(plain: str, hashed: str) -> bool:
+    return _pwd_context.verify(plain, hashed)
+
+
+# ── JWT ───────────────────────────────────────────────────────────────────────
+
+def create_access_token(user_id: int) -> str:
+    expire = datetime.now(timezone.utc) + timedelta(minutes=ACCESS_TOKEN_EXPIRE_MINUTES)
+    payload = {"sub": str(user_id), "exp": expire}
+    return jwt.encode(payload, SECRET_KEY, algorithm=ALGORITHM)
+
+
+def decode_access_token(token: str) -> int:
+    """
+    Decode the JWT and return the user_id (int).
+    Raises JWTError on any validation failure.
+    """
+    payload = jwt.decode(token, SECRET_KEY, algorithms=[ALGORITHM])
+    sub = payload.get("sub")
+    if sub is None:
+        raise JWTError("Missing subject claim.")
+    return int(sub)