def decrypt()

in browsecomp_eval.py [0:0]

• 5 lines of code
• 2 McCabe index (conditional complexity)

def decrypt(ciphertext_b64: str, password: str) -> str:
    """Decrypt base64-encoded ciphertext with XOR."""
    encrypted = base64.b64decode(ciphertext_b64)
    key = derive_key(password, len(encrypted))
    decrypted = bytes(a ^ b for a, b in zip(encrypted, key))
    return decrypted.decode()