python3 RSA 长字符串分段加密解密

1.RSA长字符串分段加密解密

import base64

from Crypto import Random
from Crypto.Cipher import PKCS1_v1_5 as Cipher_pkcs1_v1_5
from Crypto.PublicKey import RSA


class RsaCode:
    rsa_private_key = """-----BEGIN RSA PRIVATE KEY-----
    MIICXAIBAAKBgQDvluFNiF8IrIsddK0OXBAvVBJH11OKvy9er1tRGn9yEJoHCJY3
    EU/xz2LasCK8AwgRIqGJbvDBgRa70c3QT9j+wPqNqqJCSoSEKifnDUk1RgUReJT6
    iqWaJyfM+WM3aHnKl61RZL4NV5qKe4CHMtaH/JtBCC/JzpuFER1P1IhCtQIDAQAB
    AoGAaFYQb68/k4twWbeB1YsKEVJPU7HV08pGWrmKztr3PTk1mnKG2BxV8DwcFJg3
    yCCZ1rx6FFuXxOzudYR8WIctO4wdsEbFky/cEGsfc6JJjiktmZaQ7MvobGNwnoFJ
    QvRxDd+5uD87JE19iBSgUpLVtXbv+pZxSpD70vitnMdSctECQQD66Z5HsuC8DUPu
    OLQHNN4ra5Op179Xlq7LiEFW4GaVgonw24kiLX23c7CK7295Rgxct1fwQKyuU9br
    n2uj8toDAkEA9HJ85BWlm2OfUm6VI3Q99rjlpCnhRyz70+sEtf7if1SpctVxNTkX
    UOnXlpPTohjAHNhzh9fa1hh/ySH9sRMu5wJAa//8uh3br/YBxFsx2lw+OPBQGe4c
    lSXtzPu0LCHg5f/PQhYs28I696jbV6IiGFA3Z/0e4/HiohLCUp9HJMWWYwJACE53
    pfyCUyRwfomZccn6bQ7dZtWxfQyvRgU/dLvDkJYc5/UO0sMs4qf/lnNRhrmWlaRZ
    UK1qF0pf1ULdbw360wJBAObrYopW2kvIlE09j9SEgNtgVsmfZlf85c4EAZrFJP/T
    8nMNKQGo92Gd3HvbjJ+ZBOP1IFt+FDAsXeSLWLAwJrg=
    -----END RSA PRIVATE KEY-----"""

    rsa_public_key = """-----BEGIN PUBLIC KEY-----
    MIGfMA0GCSqGSIb3DQEBAQUAA4GNADCBiQKBgQDvluFNiF8IrIsddK0OXBAvVBJH
    11OKvy9er1tRGn9yEJoHCJY3EU/xz2LasCK8AwgRIqGJbvDBgRa70c3QT9j+wPqN
    qqJCSoSEKifnDUk1RgUReJT6iqWaJyfM+WM3aHnKl61RZL4NV5qKe4CHMtaH/JtB
    CC/JzpuFER1P1IhCtQIDAQAB
    -----END PUBLIC KEY-----
    """

    def encrypt(self, msg):
        msg = msg.encode('utf-8')
        rsakey = RSA.importKey(self.rsa_public_key)
        cipher = Cipher_pkcs1_v1_5.new(rsakey)
        cipher_text = base64.b64encode(cipher.encrypt(msg))
        return cipher_text

    def decrypt(self, cipher_text):
        rsakey = RSA.importKey(self.rsa_private_key)
        cipher = Cipher_pkcs1_v1_5.new(rsakey)
        random_generator = Random.new().read
        text = cipher.decrypt(base64.b64decode(cipher_text), random_generator)
        return text.decode('utf8')

    def long_encrypt(self, msg):
        msg = msg.encode('utf-8')
        length = len(msg)
        default_length = 117
        # 公钥加密
        pubobj = Cipher_pkcs1_v1_5.new(RSA.importKey(self.rsa_public_key))
        # 长度不用分段
        if length < default_length:
            return base64.b64encode(pubobj.encrypt(msg))
        # 需要分段
        offset = 0
        res = []
        while length - offset > 0:
            if length - offset > default_length:
                res.append(pubobj.encrypt(msg[offset:offset + default_length]))
            else:
                res.append(pubobj.encrypt(msg[offset:]))
            offset += default_length
        byte_data = b''.join(res)
        return base64.b64encode(byte_data)

    def long_decrypt(self, msg):
        msg = base64.b64decode(msg)
        print(msg)
        length = len(msg)
        default_length = 128
        # 私钥解密
        priobj = Cipher_pkcs1_v1_5.new(RSA.importKey(self.rsa_private_key))
        # 长度不用分段
        if length < default_length:
            return b''.join(priobj.decrypt(msg, b'xyz'))
        # 需要分段
        offset = 0
        res = []
        while length - offset > 0:
            if length - offset > default_length:
                res.append(priobj.decrypt(msg[offset:offset + default_length], b'xyz'))
            else:
                res.append(priobj.decrypt(msg[offset:], b'xyz'))
            offset += default_length

        return b''.join(res).decode('utf8')


message = '''13911236661
f954d35bf966491b982b021478241908＃android＃Nexus 6＃6.0.1＃WIFI＃Nexus 6＃zh＃CN＃google＃2392_1440＃58好借＃2.3.0＃GMT+08:00＃＃＃adcfb20011000000＃856104k＃＃＃"BSTDATA-15F-5G"＃10.15.1.74＃＃＃1＃＃0＃＃0＃2ce10d59284c091b
'''

test = RsaCode()
res_en = test.long_encrypt(message)
print('res_en', res_en)
res_de = test.long_decrypt(res_en)
print('res_de', res_de)

2.RSA加密最新(RSA/ECB/PKCS1Padding)

报错：
OverflowError: 458 bytes needed for message, but there is only space for 117

解决方式如下：

 import rsa
import base64
from Crypto.PublicKey import RSA
from Crypto.Cipher import PKCS1_v1_5 as Cipher_pkcs1_v1_5
#rsa加密，通常对加密结果进行base64编码

def handle_pub_key(key):
    """
    处理公钥
    公钥格式pem，处理成以-----BEGIN PUBLIC KEY-----开头，-----END PUBLIC KEY-----结尾的格式
    :param key:pem格式的公钥，无-----BEGIN PUBLIC KEY-----开头，-----END PUBLIC KEY-----结尾
    :return:
    """
    start = '-----BEGIN PUBLIC KEY-----\n'
    end = '-----END PUBLIC KEY-----'
    result = ''
    # 分割key，每64位长度换一行
    divide = int(len(key) / 64)
    divide = divide if (divide > 0) else divide + 1
    line = divide if (len(key) % 64 == 0) else divide + 1
    for i in range(line):
        result += key[i * 64:(i + 1) * 64] + '\n'
    result = start + result + end
    return result


def get_param(message, public_key):
    """
    处理长消息 不经过 这个处理回报下面error
    OverflowError: 458 bytes needed for message, but there is only space for 117
    :param message 消息
    :param public_key 公钥
    :return:
    """
    pubkey = rsa.PublicKey.load_pkcs1_openssl_pem(public_key)
    crypto = b''
    divide = int(len(message) / 117)
    divide = divide if (divide > 0) else divide + 1
    line = divide if (len(message) % 117 == 0) else divide + 1
    for i in range(line):
        crypto += rsa.encrypt(message[i * 117:(i + 1) * 117].encode(), pubkey)

    crypto1 = base64.b64encode(crypto)
    return crypto1.decode()



if __name__ == '__main__':
    message = "infodownloadermiddlewareshttpcompressionHttpCompressionMiddleware"*10
    public_key = "MIGfMA0GCSqGSIb3DQEBAQUAA4GNADCBiQKBgQClsqQiK5KMBO88nf2CE6I5aGJQX9jTXorDveudfSKts2/5i/ipCLo68rl4gsPYwzjP5ef5IJTK0Xdzrrfkn5d2GCVA7n/jN3rlqjfSy1w2D4JqMUtqEhRQr7KfofZbZBnPOooiepRht+W0D9rIAceLLD5UPpstZ4lPCW2t/PG0hQIDAQAB"
    public_key = handle_pub_key(public_key)
    param = get_param(message, public_key)
    print(param)