fnv1a

FNV-1a

FNV-1a hash algorithm in C#

This small project is an implementation of the FNV-1a hash algorithm for 32-, 64-, 128-, 256-, 512- and 1024-bit variants. All implemented classes descend from the System.IO.Hashing's NonCryptographicHashAlgorithm, which should make for easy adoption.

Example:

namespace Fnv1aTest
{
    using System;
    using System.Globalization;
    using System.IO.Hashing;
    using System.Text;
    
    using Fnv1a;
    
    public static class Program
    {
        public static void Main()
        {
            NonCryptographicHashAlgorithm alg = new Fnv1a64();

            alg.Append(Encoding.UTF8.GetBytes("foobar"));
            Console.WriteLine(((ulong)BitConverter.ToInt64(alg.GetCurrentHash(), 0)).ToString("X8", CultureInfo.InvariantCulture));
        }
    }
}

This will output 85944171F73967E8 as the FNV-1A 64-bit hash of the string "foobar".

Special thanks to crookseta for the missing-values project which allowed for the 256- and 512-bit variants to not have to use BigInteger, which was very slow.