Calculating Elf-32 in C# and .NET
GitHub has the latest version of Elf32
Because you can never have enough hashing algorithms at your disposal this one is compatible with the elf_hash function that forms part of the Executable and Linkable Format.
using System;
using System.Security.Cryptography;
public class Elf32 : HashAlgorithm {
private UInt32 hash;
public Elf32() {
Initialize();
}
public override void Initialize() {
hash = 0;
}
protected override void HashCore(byte[] buffer, int start, int length) {
hash = CalculateHash(hash, buffer, start, length);
}
protected override byte[] HashFinal() {
byte[] hashBuffer = UInt32ToBigEndianBytes(hash);
this.HashValue = hashBuffer;
return hashBuffer;
}
public override int HashSize { get { return 32; } }
public static UInt32 Compute(UInt32 polynomial, UInt32 seed, byte[] buffer) {
return CalculateHash(seed, buffer, 0, buffer.Length);
}
private static UInt32 CalculateHash(UInt32 seed, byte[] buffer, int start, int size) {
UInt32 hash = seed;
for (int i = start; i < size; i++)
unchecked {
hash = (hash << 4) + buffer[i];
UInt32 work = (hash & 0xf0000000);
if (work != 0)
hash ^= (work >> 24);
hash &= ~work;
}
return hash;
}
private byte[] UInt32ToBigEndianBytes(UInt32 x) {
return new byte[] {
(byte)((x >> 24) & 0xff),
(byte)((x >> 16) & 0xff),
(byte)((x >> 8) & 0xff),
(byte)(x & 0xff)
};
}
}
[)amien
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