securelib.py

import os
import hashlib
import base64

def derive_key(password: str, salt: bytes, length: int = 32) -> bytes:
    return hashlib.pbkdf2_hmac(
        hash_name='sha256',
        password=password.encode(),
        salt=salt,
        iterations=100_000,
        dklen=length
    )

def xor_crypt(data: bytes, key: bytes) -> bytes:
    return bytes(d ^ key[i % len(key)] for i, d in enumerate(data))

def encrypt(text: str, password: str) -> str:
    salt = os.urandom(16)
    key = derive_key(password, salt)
    encrypted = xor_crypt(text.encode(), key)
    return base64.b64encode(salt + encrypted).decode()

def decrypt(token: str, password: str) -> str:
    raw = base64.b64decode(token)
    salt = raw[:16]
    encrypted = raw[16:]
    key = derive_key(password, salt)
    decrypted = xor_crypt(encrypted, key)
    return decrypted.decode()