Python2 与 Python3 RSA 无填充加解密方式比较

在对固定长度字符串做加密的时候，我们由于知道字符串的长度范围，所以会用到 no padding 的加密方式。

Python2 的 M2Crypto 的 RSA 加密使用比较稳定，而且不同的填充方式用起来也比较统一。

而 Python3 的 RSA 加密模块比较多，而且使用起来不太统一， 而在 no padding 的支持上也比较难找，主流的实现方法都没有介绍，我这里也是费了九牛二虎之力找到了 Python3 中的实现方法。

下面分别介绍 Python2 和 Python3 的实现代码，备份共享。

Python2:

#!/usr/bin/python2# -*- coding: utf-8 -*-author__ = 'owen'__date__ = '2017-11-22'import M2Cryptoimport base64ENCRYPT_SALT = b'12345678901234567890123456789012345679801234' # 44 charRSA_KEY_PATH = '/home/owen/key/'class MyRSACrypto:    @classmethod    def cryptor( cls, plain_text ):        padding = 3 # no_padding        salt = ENCRYPT_SALT        base_dir = RSA_KEY_PATH        public_key = open( base_dir + 'rsa.pub').read()        # 公钥加密        buf = M2Crypto.BIO.MemoryBuffer('')        buf.write( public_key )        rsa1 = M2Crypto.RSA.load_pub_key_bio( buf )        cipher = rsa1.public_encrypt( plain_text + salt, padding )        rsa_cipher = base64.b64encode( cipher )        return rsa_cipher[:-2]    @classmethod    def decryptor( cls, cipher_text_b64 ):        padding = 3 # no_padding        salt = ENCRYPT_SALT        base_dir = RSA_KEY_PATH        private_key = open( base_dir + 'rsa.pri').read()        # 私钥解密        buf = M2Crypto.BIO.MemoryBuffer('')        buf.write( private_key )        rsa1 = M2Crypto.RSA.load_key_bio( buf )        cipher_text = base64.b64decode( cipher_text_b64 + b"==" )        plain_text = rsa1.private_decrypt( cipher_text, padding )        return plain_text[:20]if __name__ == '__main__':    text = '31' * 10    cipher_text = MyRSACrypto.cryptor( text )    print(cipher_text)    plain_text = MyRSACrypto.decryptor( cipher_text )    print( plain_text )

Python3:

author__ = 'owen'__date__ = '2017-11-22'import base64from Crypto.PublicKey import RSAENCRYPT_SALT = b'12345678901234567890123456789012345679801234' # 44 charRSA_KEY_PATH = '/home/owen/key/'class MyRSACrypto:    @classmethod    def cryptor( cls, plain_text ):        # print("\n================ crypto ========================\n")        if( not isinstance( plain_text, bytes ) ):            plain_text = plain_text.encode()        salt = ENCRYPT_SALT        base_dir = RSA_KEY_PATH        with open(base_dir + 'rsa.pub') as fp:            public_key = fp.read()        if(not public_key):            return None        rsa_cryptor = RSA.importKey( public_key )        plain_text = ( plain_text + salt )        # 无填充方式公钥加密        cipher_text = rsa_cryptor.encrypt( plain_text, 0 )        pad_cnt = 64 - len(cipher_text[0])        cipher_text_rsa = pad_cnt * b'\0' + cipher_text[0]        cipher_text_b64 = base64.b64encode( cipher_text_rsa )        return cipher_text_b64.decode()[:-2]    @classmethod    def decryptor( cls, cipher_text_b64 ):        # print("\n================ decrypto ========================\n")        if( not isinstance( cipher_text_b64, bytes ) ):            cipher_text_b64 = cipher_text_b64.encode()        base_dir = RSA_KEY_PATH        with open( base_dir + 'rsa.pri' ) as fp:            private_key = fp.read()        if(not private_key):            return None        rsa_decryptor = RSA.importKey( private_key )        cipher_text = base64.b64decode( cipher_text_b64 + b"==" )        # 无填充方式私钥解密        plain_text = rsa_decryptor.decrypt( cipher_text )        return plain_text.decode()[:20]if __name__ == '__main__':    text = '31' * 10    cipher_text = MyRSACrypto.cryptor( text )    print(cipher_text)    plain_text = MyRSACrypto.decryptor( cipher_text )    print( plain_text )