import base64
import sys
from cryptography.hazmat.primitives.ciphers import Cipher, algorithms, modes
from cryptography.hazmat.primitives import padding
from cryptography.hazmat.backends import default_backend

AES_KEY = b"KeLy8g7qjmnbgWP1"  # 16 bytes = AES-128

contents = [
    "HOmbh7KuceD2H18yBv2Hh8Wo+yZVzYtFBkY3J3eo1Pnyu0jacX6mgzwzbPzTC4KdHQia8sK5T0jfKnHPGnH5Cqc8Y+bgzN2iPXoNvgDX4OEtuyoCa+R7HknO7dLcWWPKN7Lr28x4fteCEw8YolioaFDHoZkpKla51b0qutO5wUMcfCYkg/lw8cOPB2jJwjqS1Y0YL01zaUgu24ZJHC7SwldSNtD++IgipCZtItTfgS1NmN7Qs/O/mUqox+x1AJb345vm5qhg6Q/5Bp9zXyWtn41i255CfPaW+gcqUqA248eF1BZrnzF3IkrDgysaFx/38nDYPByPO2rznmygwjjq00yhMWTHe3cKu2h3OjZvMuzuBfzE7CQwcx59/UQPBs0Fig9EPqQwHQeCRSvl1tYPm+rqlwlC+l3s3rYDaWLa3WgGrN+3HwgTGdZmJV3qajvvhxKT/BZN1zl7EfMHpu52CtM0+yrnbqWEP9heVnNJ6a8=",
    "HOmbh7KuceD2H18yBv2Hh8Wo+yZVzYtFBkY3J3eo1Pnyu0jacX6mgzwzbPzTC4KdHQia8sK5T0jfKnHPGnH5Cqc8Y+bgzN2iPXoNvgDX4OEtuyoCa+R7HknO7dLcWWPKN7Lr28x4fteCEw8YolioaO39sVqYiFSEGMa11fUhPPgq7Kx6u3SnVsiRD5ZMgqi1Nn9qBND01zsAC6WBb+/XbOYoUbMBAtwhHrzyZPBnL0emWpKPOcyU9Wr0RQbfgXkuEWAl+RM4Son1LM0wZh18aGmXfQY2lMvj/qugOXwRCadmBIeHQwkk3nkE0w67Fqn3532zCdf2GhAFMHt5jV0D3w==",
    "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"
]

def try_decrypt(ciphertext_b64, key, mode_name, iv=None):
    try:
        ct = base64.b64decode(ciphertext_b64)
        if mode_name == "ECB":
            cipher = Cipher(algorithms.AES(key), modes.ECB(), backend=default_backend())
        elif mode_name == "CBC":
            cipher = Cipher(algorithms.AES(key), modes.CBC(iv), backend=default_backend())
        else:
            return None
        decryptor = cipher.decryptor()
        pt = decryptor.update(ct) + decryptor.finalize()
        # Try PKCS7 unpad
        unpadder = padding.PKCS7(128).unpadder()
        pt = unpadder.update(pt) + unpadder.finalize()
        return pt.decode("utf-8")
    except Exception as e:
        return None

for i, ct_b64 in enumerate(contents, 1):
    print(f"\n========== Payload {i} ==========")
    # ECB
    result = try_decrypt(ct_b64, AES_KEY, "ECB")
    if result:
        print(f"[AES-128-ECB]\n{result}\n")
        continue

    # CBC with common IVs
    ivs = {
        "key as IV": AES_KEY,
        "zeros": b"\x00" * 16,
    }
    # Maybe IV is first 16 bytes of ciphertext
    ct_bytes = base64.b64decode(ct_b64)
    if len(ct_bytes) >= 16:
        ivs["first 16 bytes of cipher"] = ct_bytes[:16]

    found = False
    for iv_name, iv in ivs.items():
        result = try_decrypt(ct_b64, AES_KEY, "CBC", iv)
        if result:
            print(f"[AES-128-CBC, IV={iv_name}]\n{result}\n")
            found = True
            break
    if not found:
        print("[尝试失败] ECB 和常见 CBC IV 均无法解密，可能需要其他算法或参数。")