cryptography - C# SHA256Managed 和 cryptopp::SHA256 有什么区别

Question

我正在尝试用 cryptopp::SHA256 替换 MS SHA256Managed 函数。这是 C# 代码

internal byte[] GenerateKey(byte[] keySeed, Guid keyId)
{
        byte[] truncatedKeySeed = new byte[30];
        Array.Copy(keySeed, truncatedKeySeed, truncatedKeySeed.Length);
        Console.WriteLine("Key Seed");
        foreach (byte b in truncatedKeySeed)
        {
            Console.Write("0x" + Convert.ToString(b, 16) + ",");
        }
        Console.WriteLine();
        //
        //  Get the keyId as a byte array
        //
        byte[] keyIdAsBytes = keyId.ToByteArray();
        SHA256Managed sha_A = new SHA256Managed();
        sha_A.TransformBlock(truncatedKeySeed, 0, truncatedKeySeed.Length, truncatedKeySeed, 0);
        sha_A.TransformFinalBlock(keyIdAsBytes, 0, keyIdAsBytes.Length);

        byte[] sha_A_Output = sha_A.Hash;
        Console.WriteLine("sha_a:" + sha_A_Output.Length);
        foreach (byte b in sha_A_Output)
        {
            Console.Write("0x" + Convert.ToString(b, 16) + ",");
        }
        Console.WriteLine(); 
        .....
}

输出结果:

关键种子0x5d,0x50,0x68,0xbe,0xc9,0xb3,0x84,0xff,0x60,0x44,0x86,0x71,0x59,0xf1,0x6d,0x6b,0x75,0x55,0x44,0xfc,0xd5,0x11,0x69,0x89,0xb 1、 0xac,0xc4,0x27,0x8e,0x88

key ID0x39,0x68,0xe1,0xb6,0xbd,0xee,0xf6,0x4f,0xab,0x76,0x8d,0x48,0x2d,0x8d,0x2b,0x6a,

sha_a:320x7b,0xec,0x8f,0x1b,0x60,0x4e,0xb4,0xab,0x3b,0xb,0xbd,0xb8,0x71,0xd6,0xba,0x71,0xb1,0x26,0x41,0x7d,0x99,0x55,0xdc,0x8e,0x64, 0x76,0x15,0x23,0x1b,0xab,0x76,0x62,

Crypto++的替换函数如下:

  byte key_seed[] = { 0x5D, 0x50, 0x68, 0xBE, 0xC9, 0xB3, 0x84, 0xFF, 0x60, 0x44, 0x86, 0x71, 0x59, 0xF1, 0x6D, 0x6B, 0x75, 0x55, 0x44, 0xFC,0xD5, 0x11, 0x69, 0x89, 0xB1, 0xAC, 0xC4, 0x27, 0x8E, 0x88 };
  byte key_id[] = { 0x39,0x68,0xe1,0xb6,0xbd,0xee,0xf6,0x4f,0xab,0x76,0x8d,0x48,0x2d,0x8d,0x2b,0x6a };
  byte truncated_key_seed[sizeof(key_seed)];
  memset( truncated_key_seed,0,sizeof(truncated_key_seed));
  memcpy( key_seed, truncated_key_seed, sizeof(key_seed) );
  byte output[SHA256::DIGESTSIZE];
  memset(output,0,sizeof(output));

  SHA256 sha_a;
  sha_a.Update(truncated_key_seed,sizeof(key_seed));
  sha_a.Update(key_id,sizeof(key_id));
  sha_a.Final(output);
  printf("size:%lu\n",sizeof(output));
  PrintHex(output,sizeof(output));

但是输出的哈希值是DB 36 C9 F6 F7 29 6D 6F 52 21 DA 9F 55 1D AE BC 3E 5A 15 DF E1 37 07 EE 8F BC 73 61 5F D6 E1 C3与C#的sha_a结果不同。

来自MSDN和 Cryptopp reference ，SHA256Managed::TransformBlock 和 SHA256Managed::TransformFinalBlock 对 Cryptopp::Update 和 Cryptopp::Final 做了同样的事情。

SHA256Managed 和 cryptopp::SHA256 之间的区别是什么导致了这个结果？

Answer 1

对我来说，这似乎是你的代码中的一个错误。

  sha_a.Update(truncated_key_seed,sizeof(key_seed));

确保两个版本中的 truncated_key_seed 相同，尤其是原始 key_seed 中未包含的字节...