MurmurHash3 Test Vectors

Question

MurmurHash3 Test Vectors

I am trying to pass a C # MurmurHash3 implementation to VB.Net.

It works ... but can anyone provide me with some well-known test vectors to check for correctness?

Known string text
Seed value
MurmurHash3 Result

Thanks in advance.

Edit: I limit the implementation to only 32-bit MurmurHash3, but if you can also provide vectors for a 64-bit implementation, that would be fine too.

+5

vb.net murmurhash

pepoluan Feb 07 '13 at 9:09

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3 answers

SMHasher , , , ( 256) :

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

HASHLENGTH * 256, :

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

. 4 32- :

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

, , . , C .

# .

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);
    }
}

+5

Jonathan Dickinson 28 '13 15:39

. Murmur3 ICryptoTransform, . github .

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);
        }
    }
}

, ICryptoTransform, int ( byte[]). :

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);
    }
}

0

U. Bulle 18 . '16 23:04

Ian Boyd · Accepted Answer · 2015-08-10T21:31:00+0000

- MurMur3, SMHasher. , SMHasher. , , , .

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 |

, , , . :

UTF-8

:

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 canonical BCrypt implementation did)
TestString(StringOfChar("a", 256), 0x9747b28c, 0x37405BDC);

11 SHA-2, Murmur3.

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

, , :

: "The quick brown fox jumps over the lazy dog"
: 0x9747b28c
: 0x2FA826CD

- / .

, , , SMHasher 256 KeySetTest.cpp - VerificationTest(...).

Delphi. Lua ( ).

. , . .

MurmurHash3 Test Vectors

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