MurmurHash3测试矢量

Question

我正在尝试将一个C#实现MurmurHash3移植到VB.Net。

它运行..。但是有人能为我提供一些已知的测试向量来验证正确性吗？

• 已知字符串文本
• 种子值
• MurmurHash3结果

提前谢谢。

编辑: --我把实现限制在32位MurmurHash3上，但是如果你也能为64位实现提供向量，也会很好。

Answer 1

我终于开始创建一个MurMur3实现，并成功地翻译了SMHasher测试代码。我的实现给出了与SMHasher测试相同的结果。这意味着我最终可以给出一些有用的，并且假设是正确的测试向量。

这只适用于Murmur3_x86_32

| Input        | Seed       | Expected   |
|--------------|------------|------------|
| (no bytes)   | 0          | 0          | with zero data and zero seed, everything becomes zero
| (no bytes)   | 1          | 0x514E28B7 | ignores nearly all the math
| (no bytes)   | 0xffffffff | 0x81F16F39 | make sure your seed uses unsigned 32-bit math
| FF FF FF FF  | 0          | 0x76293B50 | make sure 4-byte chunks use unsigned math
| 21 43 65 87  | 0          | 0xF55B516B | Endian order. UInt32 should end up as 0x87654321
| 21 43 65 87  | 0x5082EDEE | 0x2362F9DE | Special seed value eliminates initial key with xor
| 21 43 65     | 0          | 0x7E4A8634 | Only three bytes. Should end up as 0x654321
| 21 43        | 0          | 0xA0F7B07A | Only two bytes. Should end up as 0x4321
| 21           | 0          | 0x72661CF4 | Only one byte. Should end up as 0x21
| 00 00 00 00  | 0          | 0x2362F9DE | Make sure compiler doesn't see zero and convert to null
| 00 00 00     | 0          | 0x85F0B427 | 
| 00 00        | 0          | 0x30F4C306 |
| 00           | 0          | 0x514E28B7 |

对于那些将要移植到没有实际数组的语言的人来说，我也有一些基于字符串的测试。对于这些测试：

• 所有字符串都假定为UTF-8编码。
• 并且不包括任何空终止符。

我会把这些放在代码表格中：

TestString("", 0, 0); //empty string with zero seed should give zero
TestString("", 1, 0x514E28B7);
TestString("", 0xffffffff, 0x81F16F39); //make sure seed value is handled unsigned
TestString("\0\0\0\0", 0, 0x2362F9DE); //make sure we handle embedded nulls


TestString("aaaa", 0x9747b28c, 0x5A97808A); //one full chunk
TestString("aaa", 0x9747b28c, 0x283E0130); //three characters
TestString("aa", 0x9747b28c, 0x5D211726); //two characters
TestString("a", 0x9747b28c, 0x7FA09EA6); //one character

//Endian order within the chunks
TestString("abcd", 0x9747b28c, 0xF0478627); //one full chunk
TestString("abc", 0x9747b28c, 0xC84A62DD);
TestString("ab", 0x9747b28c, 0x74875592);
TestString("a", 0x9747b28c, 0x7FA09EA6);

TestString("Hello, world!", 0x9747b28c, 0x24884CBA);

//Make sure you handle UTF-8 high characters. A bcrypt implementation messed this up
TestString("ππππππππ", 0x9747b28c, 0xD58063C1); //U+03C0: Greek Small Letter Pi

//String of 256 characters.
//Make sure you don't store string lengths in a char, and overflow at 255 bytes (as OpenBSD's canonical BCrypt implementation did)
TestString(StringOfChar("a", 256), 0x9747b28c, 0x37405BDC);

我将只发布我转换为Murmur3的11个SHA-2测试向量中的两个。

TestString("abc", 0, 0xB3DD93FA);
TestString("abcdbcdecdefdefgefghfghighijhijkijkljklmklmnlmnomnopnopq", 0, 0xEE925B90);

最后，最重要的是：

• 密钥： "The quick brown fox jumps over the lazy dog"
• 种子： 0x9747b28c
• Hash：0x2FA826CD

如果其他人可以从它们的实现中确认任何/所有这些向量。

而且，同样，这些测试向量来自通过SMHasher 256迭代循环测试的KeySetTest.cpp - VerificationTest(...)实现。

这些测试来自于我在Delphi中的实现。我还在Lua中创建了一个实现(在支持数组方面不是很大)。

注意事项：发布到公共域中的任何代码。不需要归属。

Answer 2

SMHasher使用一个检查散列是否正常工作的小例程，基本上计算以下值的散列数，对每个值使用一个递减的种子值(从256个开始)：

' The comment in the SMHasher code is a little wrong -
' it's missing the first case.
{}, {0}, {0, 1}, {0, 1, 2} ... {0, 1, 2, ... 254}

并将其追加到HASHLENGTH * 256长度数组中，换句话说：

' Where & is a byte array concatenation.
HashOf({}, 256) &
HashOf({0}, 255) &
HashOf({0, 1}, 254) &
...
HashOf({0, 1, ... 254), 1)

然后，它接受那个大数组的散列。最后哈希的前4个字节被解释为一个无符号的32位整数，并根据验证代码进行检查：

• MurmurHash3 x86 32 0xB0F57EE3
• MurmurHash3 x86 128 0xB3ECE62A
• MurmurHash3 x64 128 0x6384BA69

不幸的是这是我唯一能找到的公开测试。我想另一个选择是编写一个快速的C应用程序并散列一些值。

这是我的验证器的C#实现。

static void VerificationTest(uint expected)
{
    using (var hash = new Murmur3())
    // Also test that Merkle incremental hashing works.
    using (var cs = new CryptoStream(Stream.Null, hash, CryptoStreamMode.Write))
    {
        var key = new byte[256];

        for (var i = 0; i < 256; i++)
        {
            key[i] = (byte)i;
            using (var m = new Murmur3(256 - i))
            {
                var computed = m.ComputeHash(key, 0, i);
                // Also check that your implementation deals with incomplete
                // blocks.
                cs.Write(computed, 0, 5);
                cs.Write(computed, 5, computed.Length - 5);
            }
        }

        cs.FlushFinalBlock();
        var final = hash.Hash;
        var verification = ((uint)final[0]) | ((uint)final[1] << 8) | ((uint)final[2] << 16) | ((uint)final[3] << 24);
        if (verification == expected)
            Console.WriteLine("Verification passed.");
        else
            Console.WriteLine("Verification failed, got {0:x8}, expected {1:x8}", verification, expected);
    }
}

Answer 3

我改进了乔纳森的救生代码。您的Murmur3必须实现ICryptoTransform才能使此方法工作。您可以在github上找到实现此接口的一个。

public static  void VerificationTest(uint expected)
{
    using (var hash = new Murmur32ManagedX86())
    {
        using (var cs = new CryptoStream(Stream.Null, hash, CryptoStreamMode.Write))
        {
            var key = new byte[256];

            for (var i = 0; i < 256; i++)
            {
                key[i] = (byte)i;
                using (var mur = new Murmur32ManagedX86((uint)(256 - i)))
                {
                    var computed = mur.ComputeHash(key, 0,i);
                    cs.Write(computed, 0, 4);
                }
            }
            cs.FlushFinalBlock();
            var testBoy = hash.Seed;

            var final = hash.Hash;
            var verification = ((uint)final[0]) | ((uint)final[1] << 8) | ((uint)final[2] << 16) | ((uint)final[3] << 24);
            if (verification == expected)
                Console.WriteLine("Verification passed.");
            else
                Console.WriteLine("Verification failed, got {0:x8}, expected {1:x8}", verification, expected);
        }
    }
}

如果您使用的实现没有ICryptoTransform接口，但只处理字节并返回int (也可以轻松修改以使用byte[] )。下面是该函数的测试函数：

public static void VerificationTest(uint expected)
{
    using (var stream = new MemoryStream())
    {
        var key = new byte[256];

        for (var i = 0; i < 256; i++)
        {
            key[i] = (byte)i;
            var hasher = new MurMurHash3((uint)(256 - i));

            int computed = hasher.ComputeBytesFast(key.Take(i).ToArray());
            stream.Write(BitConverter.GetBytes(computed), 0, 4);
        }
        var finalHasher = new MurMurHash3(0); //initial seed = 0
        int result = finalHasher.ComputeBytesFast2(stream.GetBuffer());
        if (result == (int)expected)
            Console.WriteLine("Verification passed.");
        else
            Console.WriteLine("Verification failed, got {0:x8}, expected {1:x8}", verification, expected);
    }
}