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python - 执行 AES CBC 128 无法获得与在线工具相同的相同结果

问题描述

我使用从第三方服务器获取加密消息。

我在这里使用输入链接描述中的工具

测试和正确

The Encrypted Text = 
"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"

Key = "1234567812345678"

AES 解密输出 (Base64) 后的结果： 解码纯文本后的结果是：

{"upPacketSN":-1,"upDataSN":-1,"topic":"v1/up/ad","timestamp":1619672797621,"tenantId":"2000034792","serviceId":"","protocol":"lwm2m","productId":"15044315","payload":{"APPdata":"MTIzNDU2NzgsNTM0OCwwNywwOCwyNTUsMTc5LDEyOCwwMDAwLDQyNTksMSw2LDAsMCwwLDAsMCwwLDI0LDMuNzAsMy43MCwxLDEsNiwsMCwwLDAsMCwwLDAsMCwwLDAsMCwtMjU1LC0yNTUsLTI1NSwxLjY5LDEuOCw0OTk4LDYwLDE0NDAsNjA="},"messageType":"dataReport","deviceType":"","deviceId":"523ede8bb7e34dd4a1bd74028d63749e","assocAssetId":"","IMSI":"undefined","IMEI":"864162041961023"}

其中一件事是 IV 必须为 NULL 才能获得正确的答案。

因此，如果我使用 pycryptodome 库在 Python AES CBC 中实现，如下所示：

class AES_CBC:
 
    def add_to_16(self, value):
        while len(value) % 16 != 0:
            value += '\0'
        return str.encode(value)  # 返回bytes
 
   
    
    #解密方法
    def decrypt_oralce(self, key, text):
        # 初始化加密器
        # 偏移量 16个0
        iv = "0000000000000000"
        aes = AES.new(self.add_to_16(key), AES.MODE_CBC, self.add_to_16(iv))
        #优先逆向解密base64成bytes
        base64_decrypted = base64.decodebytes(text.encode(encoding='utf-8'))
        #
        decrypted_text = str(aes.decrypt(base64_decrypted), encoding='utf-8') # 执行解密密并转码返回str
        unpad = lambda s : s[0:-ord(s[-1])]
        #PADDING = '\0'
        #print decrypted_text.rstrip(PADDING)  #zeropadding只见诶去掉结尾\0
        # print(unpad(decrypted_text))
        return unpad(decrypted_text)
 
 
if __name__ == '__main__':
    aes = AES_CBC()
    #加密
    key = "1234567812345678"
    enc_msg = "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"
 
    #解密
    dec_text = aes.decrypt_oralce(key, enc_msg)
    print(key)
    print(dec_text)

已编辑：我使用相同的 IV 16'0' 得到了不同的结果，来自网络的结果是

{"upPacketSN":-1,"upDataSN":-1,"topic":"v1/up/ad","timestamp":1619687373640,"tenantId":"2000034792","serviceId":"","protocol":"lwm2m","productId":"15044315","payload":{"APPdata":"MTIzNDU2NzgsNTM0OCwwNywwOCwyNTUsMTc5LDEyOCwwMDAwLDQ1MDQsMSw2LDAsMCwwLDAsMCwwLDI0LDMuNzAsMy43MCwxLDEsNiwsMCwwLDAsMCwwLDAsMCwwLDAsMCwtMjU1LC0yNTUsLTI1NSwxLjY5LDEuOCw0OTk4LDYwLDE0NDAsNjA="},"messageType":"dataReport","deviceType":"","deviceId":"523ede8bb7e34dd4a1bd74028d63749e","assocAssetId":"","IMSI":"undefined","IMEI":"864162041961023"}

而我的代码的结果是：

KE@`QS[UDc~
1,"upDataSN":-1,"topic":"v1/up/ad","timestamp":1619687373640,"tenantId":"2000034792","serviceId":"","protocol":"lwm2m","productId":"15044315","payload":{"APPdata":"MTIzNDU2NzgsNTM0OCwwNywwOCwyNTUsMTc5LDEyOCwwMDAwLDQ1MDQsMSw2LDAsMCwwLDAsMCwwLDI0LDMuNzAsMy43MCwxLDEsNiwsMCwwLDAsMCwwLDAsMCwwLDAsMCwtMjU1LC0yNTUsLTI1NSwxLjY5LDEuOCw0OTk4LDYwLDE0NDAsNjA="},"messageType":"dataReport","deviceType":"","deviceId":"523ede8bb7e34dd4a1bd74028d63749e","assocAssetId":"","IMSI":"undefined","IMEI":"864162041961023"}

谁能帮我哪部分错了？

谢谢

标签： pythonencryptionaescbc-mode

解决方案

目前代码没有使用“null-IV”，这意味着一个数组填充了设置为零的字节。相反，它使用的是一个填充了'0'字符的数组，这些字符的值0x30是十六进制或十进制的 48；显然不为零。

要创建 null-IV，请在此处查看如何在 Python 中的字节数组中指示字节值。add_to_16在循环中使用了相同的技巧，其中\0转义用于指示零字节。

请注意，填充键或 IV 是非常糟糕的做法。这些需要由随机字节组成。请注意，工作加密代码与安全加密代码不同，这可能是您的目标。

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