itcloud/backend/src/app/infra/security.py

"""Security utilities for authentication and authorization."""

import base64
import hashlib
from datetime import datetime, timedelta, timezone
from typing import Optional

from jose import JWTError, jwt
from passlib.context import CryptContext

from app.infra.config import get_settings

settings = get_settings()

# Password hashing context
pwd_context = CryptContext(schemes=["bcrypt"], deprecated="auto")


def hash_password(password: str) -> str:
    """
    Hash a password using bcrypt with SHA256 pre-hashing.

    Args:
        password: Plain text password (any length supported)

    Returns:
        Hashed password

    Note:
        Uses SHA256 pre-hashing to support passwords of any length,
        avoiding bcrypt's 72-byte limitation.
    """
    # Pre-hash with SHA256 to support unlimited password length
    # Use base64 encoding for compact representation (43 chars < 72 bytes)
    password_bytes = hashlib.sha256(password.encode('utf-8')).digest()
    password_hash = base64.b64encode(password_bytes).decode('ascii')
    return pwd_context.hash(password_hash)


def verify_password(plain_password: str, hashed_password: str) -> bool:
    """
    Verify a password against its hash.

    Args:
        plain_password: Plain text password
        hashed_password: Hashed password to verify against

    Returns:
        True if password matches, False otherwise
    """
    # Apply same SHA256 pre-hashing as hash_password
    password_bytes = hashlib.sha256(plain_password.encode('utf-8')).digest()
    password_hash = base64.b64encode(password_bytes).decode('ascii')
    return pwd_context.verify(password_hash, hashed_password)


def create_access_token(data: dict, expires_delta: Optional[timedelta] = None) -> str:
    """
    Create a JWT access token.

    Args:
        data: Data to encode in the token
        expires_delta: Optional expiration time delta

    Returns:
        Encoded JWT token
    """
    to_encode = data.copy()
    if expires_delta:
        expire = datetime.now(timezone.utc) + expires_delta
    else:
        expire = datetime.now(timezone.utc) + timedelta(seconds=settings.jwt_access_ttl_seconds)

    to_encode.update({"exp": expire, "type": "access"})
    encoded_jwt = jwt.encode(to_encode, settings.jwt_secret, algorithm=settings.jwt_algorithm)
    return encoded_jwt


def create_refresh_token(data: dict) -> str:
    """
    Create a JWT refresh token.

    Args:
        data: Data to encode in the token

    Returns:
        Encoded JWT token
    """
    to_encode = data.copy()
    expire = datetime.now(timezone.utc) + timedelta(seconds=settings.jwt_refresh_ttl_seconds)
    to_encode.update({"exp": expire, "type": "refresh"})
    encoded_jwt = jwt.encode(to_encode, settings.jwt_secret, algorithm=settings.jwt_algorithm)
    return encoded_jwt


def decode_token(token: str) -> Optional[dict]:
    """
    Decode and verify a JWT token.

    Args:
        token: JWT token to decode

    Returns:
        Decoded token payload or None if invalid
    """
    try:
        payload = jwt.decode(token, settings.jwt_secret, algorithms=[settings.jwt_algorithm])
        return payload
    except JWTError:
        return None