Python 3.x 根据ISO 9797 Alg3从纯文本生成MAC

我需要生成基于ISO 9797 Alg3从纯文本的MAC。我已经用“BouncyCastle”工具用java和C#编写了一个相同的函数，非常简单，如下代码所示。但是，互联网上没有任何python示例

using System.Text;
using Org.BouncyCastle.Crypto.Parameters;
using Org.BouncyCastle.Crypto.Engines;
using Org.BouncyCastle.Crypto.Macs;
using System.Security.Cryptography;
using System.IO;

namespace TestGenerateMAC2
{
    class Program
    {
        public static string getMac(string text, string key)
        {
            byte[] keyBytes = StringToByteArray(key);
            byte[] data = Encoding.UTF8.GetBytes(text);
            DesEngine cipher = new DesEngine();
            ISO9797Alg3Mac mac = new ISO9797Alg3Mac(cipher);

            KeyParameter keyP = new KeyParameter(keyBytes);
            mac.Init(keyP);
            mac.BlockUpdate(data, 0, data.Length);

            byte[] outPut = new byte[8];

            mac.DoFinal(outPut, 0);

            return BytesToHex(outPut);
        }
        public static byte[] StringToByteArray(string hex)
        {
            return Enumerable.Range(0, hex.Length)
                             .Where(x => x % 2 == 0)
                             .Select(x => Convert.ToByte(hex.Substring(x, 2), 16))
                             .ToArray();
        }

        public static string BytesToHex(byte[] bytes)
        {
            return String.Concat(Array.ConvertAll(bytes, delegate (byte x) { return x.ToString("X2"); })).ToLower();
        }

  }
}

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python中是否有相同的示例

请求样本显然是离题的，但我将说明如何使用DES CBC和DES ECB密码创建算法

所有操作都是在字节或字节数组上进行的

将16字节密钥拆分为密钥A和密钥B

使用密钥A和8字节的全零IV初始化DES CBC加密

迭代消息中的所有完整块&对于每个块，执行CBC加密，丢弃结果（使用相同的密码实例，您毕竟需要保持状态）

创建最后一个块，并将消息中剩余的字节复制到其中

在下一个位置添加初始填充指示器字节

通过加密最后一个块来完成CBC加密，并保留结果

使用密钥B对结果执行DES ECB解密，替换结果

使用密钥A对结果进行加密，替换结果

然后当然返回结果

。。。快乐编程

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好吧，既然答案被接受了，我将放弃不发布示例代码的警告，发布我自己的代码，只是为了展示良好的编程实践（只要我能够用我对Python的理解创建这些实践）：

请注意，上述代码中DES/cipher对象的API文档没有明确说明返回了什么数据以及何时返回。因此，我加入了一个

if

语句来检索当前实现显然不需要的最后一块密文。这可能过于谨慎了（但这是加密域带来的）

还要注意，我已经为消息本身之外的填充创建了最后一个块。填充消息本身既危险（您可能希望将消息用于其他方式）又占用大量资源，因为复制大型消息是个坏主意。

谢谢Maarten

我根据你的描述找到并更改了一个代码。下面的代码解决了我的问题

多谢各位

import sys
from Crypto.Cipher import DES
from Crypto.Cipher import DES3
from Crypto.Util.strxor import strxor
import binascii


def macIso9797_m2_alg3(key, msg):
    return macIso9797_alg3(key, msg, "80")

def macIso9797_m1_alg3(key, msg):
    return macIso9797_alg3(key, msg, "00")

def macIso9797_alg3(key, msg, pad_start):

    key_len = int(len(key)/2)    

    if (key_len != 16):
        raise ValueError("Key length should be 16 digits")    

    # force header  padding
    msg += pad_start

    # padding with "00"
    lenRestOfData = int((len(msg)/2) % 8)
    msg += "00"*(8-lenRestOfData)

    loopNum = int((len(msg)/2) / 8)

    bufferOutput = binascii.unhexlify("00"*8)
    IV = '\x00'*8    

    keya = binascii.unhexlify(key[0:16])
    keyb = binascii.unhexlify(key[16:])

    i = 0
    for i in range (0, loopNum):
        tdesa = DES.new(keya, DES.MODE_ECB)

        data = msg[i*16:i*16+16]

        x = bufferOutput
        bufferOutput = strxor(binascii.unhexlify(data), bufferOutput)

        bufferOutput = tdesa.encrypt(bufferOutput)

    tdesb = DES.new(keyb, DES.MODE_ECB)
    bufferOutput = tdesb.decrypt(bufferOutput)

    tdesa = DES.new(keya, DES.MODE_ECB)
    bufferOutput = tdesa.encrypt(bufferOutput)

    return bufferOutput


macKey="mac key"
message="text message"

hexMessage = bytes(message, encoding='utf-8').hex()

print('MAC Key: ' + macKey)
print('MAC: ' + macIso9797_m1_alg3(macKey, hexMessage).hex())

import sys
from Crypto.Cipher import DES
from Crypto.Cipher import DES3
from Crypto.Util.strxor import strxor
import binascii


def macIso9797_m2_alg3(key, msg):
    return macIso9797_alg3(key, msg, "80")

def macIso9797_m1_alg3(key, msg):
    return macIso9797_alg3(key, msg, "00")

def macIso9797_alg3(key, msg, pad_start):

    key_len = int(len(key)/2)    

    if (key_len != 16):
        raise ValueError("Key length should be 16 digits")    

    # force header  padding
    msg += pad_start

    # padding with "00"
    lenRestOfData = int((len(msg)/2) % 8)
    msg += "00"*(8-lenRestOfData)

    loopNum = int((len(msg)/2) / 8)

    bufferOutput = binascii.unhexlify("00"*8)
    IV = '\x00'*8    

    keya = binascii.unhexlify(key[0:16])
    keyb = binascii.unhexlify(key[16:])

    i = 0
    for i in range (0, loopNum):
        tdesa = DES.new(keya, DES.MODE_ECB)

        data = msg[i*16:i*16+16]

        x = bufferOutput
        bufferOutput = strxor(binascii.unhexlify(data), bufferOutput)

        bufferOutput = tdesa.encrypt(bufferOutput)

    tdesb = DES.new(keyb, DES.MODE_ECB)
    bufferOutput = tdesb.decrypt(bufferOutput)

    tdesa = DES.new(keya, DES.MODE_ECB)
    bufferOutput = tdesa.encrypt(bufferOutput)

    return bufferOutput


macKey="mac key"
message="text message"

hexMessage = bytes(message, encoding='utf-8').hex()

print('MAC Key: ' + macKey)
print('MAC: ' + macIso9797_m1_alg3(macKey, hexMessage).hex())