Python 用 PyCrypto, M2Crypto, ncrypt, cryptography 3DES ECB mode 加密解密 demo。

cryptography_3des_demo.py

import os
from cryptography.hazmat.primitives.ciphers import Cipher, algorithms, modes
from cryptography.hazmat.primitives import padding
from cryptography.hazmat.backends import default_backend
backend = default_backend()
key = os.urandom(16)

text = b'Hello, there!'

padder = padding.PKCS7(algorithms.TripleDES.block_size).padder()
unpadder = padding.PKCS7(algorithms.TripleDES.block_size).unpadder()

cipher = Cipher(algorithms.TripleDES(key), modes.ECB(), backend=backend)

encryptor = cipher.encryptor()
decryptor = cipher.decryptor()

encrypted_text = encryptor.update(padder.update(text) + padder.finalize()) + encryptor.finalize()
decrypted_text = unpadder.update(decryptor.update(encrypted_text) + decryptor.finalize()) + unpadder.finalize()

assert text == decrypted_text

m2crypto_3des_demo.py

# -*- Encoding: utf-8 -*-

from M2Crypto.EVP import Cipher


key = 'a' * 16
text = 'Hello, there!'

cipher = Cipher(alg='des_ede_ecb', key=key, op=1, iv='\0'*16)

encrypted_text = cipher.update(text)
encrypted_text += cipher.final()

decipher = Cipher(alg='des_ede_ecb', key=key, op=0, iv='\0'*16)

decrypted_text = decipher.update(encrypted_text)
decrypted_text += decipher.final()

assert text == decrypted_text

ncrypt_3des_demo.py

# -*- Encoding: utf-8 -*-

from ncrypt.cipher import CipherType, EncryptCipher, DecryptCipher


cipher_type = CipherType('DES-EDE3', 'ECB')
key = 'a' * cipher_type.keyLength()
iv = '\0' * cipher_type.ivLength()

text = 'Hello, there!'


def do_encrypt(cipher_type, key, iv, plain_text):
    enc = EncryptCipher(cipher_type, key, iv)
    cipher_text = enc.finish(plain_text)
    return cipher_text


def do_decrypt(cipher_type, key, iv, cipher_text):
    dec = DecryptCipher(cipher_type, key, iv)
    plain_text = dec.finish(cipher_text)
    return plain_text


encrypted_text = do_encrypt(cipher_type, key, iv, text)
decrypted_text = do_decrypt(cipher_type, key, iv, encrypted_text)

assert text == decrypted_text

pycrypto_3des_demo.py

# -*- Encoding: utf-8 -*-

from Crypto.Cipher import DES3


BS = DES3.block_size

pad = lambda s: s + (BS - len(s) % BS) * chr(BS - len(s) % BS)
unpad = lambda s : s[0:-ord(s[-1])]

key = 'a' * 16
text = 'Hello, there!'

cipher = DES3.new(key, DES3.MODE_ECB)

encrypted_text = cipher.encrypt(pad(text))
decrypted_text = unpad(cipher.decrypt(encrypted_text))

assert text == decrypted_text