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| 1 | +# Python之AES加密解密 |
| 2 | +## 一、AES/CBC/PKCS5Padding加密解密 |
| 3 | + |
| 4 | + from Cryptodome.Cipher import AES, DES |
| 5 | + import base64 |
| 6 | + class AESCrypter(): |
| 7 | + """ |
| 8 | + AES.MODE_CBC |
| 9 | + PKCS5Padding |
| 10 | + PKCS5Padding：填充的原则是，如果长度少于16个字节，需要补满16个字节，补(16-len)个(16-len)例如： |
| 11 | + huguozhen这个节符串是9个字节，16-9= 7,补满后如：huguozhen+7个\x07，如果刚好是倍数，那么补16个\x10 |
| 12 | + 由于加密过程有补齐操作，因此不适用于按块加密文件，加密前后文件大小改变了，无法按块还原 |
| 13 | + 文件加密，逐包加解密，还是可行的 |
| 14 | + """ |
| 15 | + |
| 16 | + def __init__(self, key, iv=None): |
| 17 | + """ |
| 18 | + :param key: 16*n个字节，bytes |
| 19 | + """ |
| 20 | + self.key = key |
| 21 | + if iv: |
| 22 | + self.iv = iv |
| 23 | + else: |
| 24 | + self.iv = key |
| 25 | + self.mode = AES.MODE_CBC |
| 26 | + self.BS = len(key) |
| 27 | + # 如果刚好是s是BS的倍数，那么补一组 |
| 28 | + self.pad = lambda s: s + (self.BS - len(s) % self.BS) * chr(self.BS - len(s) % self.BS).encode() |
| 29 | + self.unpad = lambda s: s[0:-s[-1]] |
| 30 | + self.generator_en = AES.new(self.key, self.mode, self.iv) |
| 31 | + self.generator_de = AES.new(self.key, self.mode, self.iv) |
| 32 | + |
| 33 | + def encrypt(self, en_data): |
| 34 | + """ |
| 35 | + :param en_data: bytes |
| 36 | + :return: bytes |
| 37 | + """ |
| 38 | + return self.generator_en.encrypt(self.pad(en_data)) |
| 39 | + |
| 40 | + def decrypt(self, de_data): |
| 41 | + """ |
| 42 | + :param de_data: bytes |
| 43 | + :return: bytes |
| 44 | + """ |
| 45 | + return self.unpad(self.generator_de.decrypt(de_data)) |
| 46 | + |
| 47 | + |
| 48 | + if __name__ == '__main__': |
| 49 | + key = b'0' * 16 |
| 50 | + iv = b'12345678' * 2 |
| 51 | + |
| 52 | + data = '你好，这个数据好很重要，要加密！！！' |
| 53 | + aes = AESCrypter(key, iv) |
| 54 | + en_data = base64.b64encode(aes.encrypt(data.encode('utf-8'))) |
| 55 | + print(en_data) # b'lqDad0GkXYwNxf+jxoXg4661qhSk9cTKqDPPOtAjXGd1aru61grhjpQw9qIxitcarfePNiDnL06yJqglcwPuDg==' |
| 56 | + de_data = aes.decrypt(base64.b64decode(en_data)).decode('utf-8') |
| 57 | + print(de_data) |
| 58 | + |
| 59 | +## 二、DES/CBC/PKCS5Padding加密解密 |
| 60 | + |
| 61 | + from Cryptodome.Cipher import DES |
| 62 | + import base64 |
| 63 | + |
| 64 | + |
| 65 | + class DESCrypter(): |
| 66 | + |
| 67 | + def __init__(self, key, iv=None): |
| 68 | + self.key = key |
| 69 | + if iv: |
| 70 | + self.iv = iv |
| 71 | + else: |
| 72 | + self.iv = key |
| 73 | + self.mode = DES.MODE_CBC |
| 74 | + self.BS = len(key) |
| 75 | + # 如果刚好是s是BS的倍数，那么补一组 |
| 76 | + self.pad = lambda s: s + (self.BS - len(s) % self.BS) * chr(self.BS - len(s) % self.BS).encode() |
| 77 | + self.unpad = lambda s: s[0:-s[-1]] |
| 78 | + self.generator_en = DES.new(self.key, self.mode, self.iv) |
| 79 | + self.generator_de = DES.new(self.key, self.mode, self.iv) |
| 80 | + |
| 81 | + def encrypt(self, en_data): |
| 82 | + return self.generator_en.encrypt(self.pad(en_data)) |
| 83 | + |
| 84 | + def decrypt(self, de_data): |
| 85 | + return self.unpad(self.generator_de.decrypt(de_data)) |
| 86 | + |
| 87 | + |
| 88 | + if __name__ == '__main__': |
| 89 | + key = b'00000000' |
| 90 | + iv = b'12345678' |
| 91 | + des = DESCrypter(key, iv) |
| 92 | + data = '这个数据要加密！！！！' |
| 93 | + |
| 94 | + en_data = base64.b64encode(des.encrypt(data.encode('utf-8'))) |
| 95 | + print(en_data) # b'p1AmnxW64yb8E7RdU3gq7nk/gDQ407yLFs5Ziilq2r/gBXBPUcOeyw==' |
| 96 | + |
| 97 | + de_data = des.decrypt(base64.b64decode(en_data)).decode('utf-8') |
| 98 | + print(de_data) |
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