Implementation of IPasswordHasher of JWT API.

PasswordHasher.cs

public class PasswordHasher : IPasswordHasher
{
    public string HashPassword(string password)
    {
        byte[] salt;
        byte[] buffer2;
        if (string.IsNullOrEmpty(password))
        {
            throw new ArgumentNullException("password");
        }
        using(Rfc2898DeriveBytes bytes = new Rfc2898DeriveBytes(password, 0x10, 0x3e8))
        {
            salt = bytes.Salt;
            buffer2 = bytes.GetBytes(0x20);
        }
        byte[] dst = new byte[0x31];
        Buffer.BlockCopy(salt, 0, dst, 1, 0x10);
        Buffer.BlockCopy(buffer2, 0, dst, 0x11, 0x20);
        return Convert.ToBase64String(dst);
    }

    public bool PasswordMatches(string providedPassword, string passwordHash)
    {
        byte[] buffer4;
        if (passwordHash == null)
        {
            return false;
        }
        if (providedPassword == null)
        {
            throw new ArgumentNullException("providedPassword");
        }
        byte[] src = Convert.FromBase64String(passwordHash);
        if ((src.Length != 0x31) || (src[0] != 0))
        {
            return false;
        }
        byte[] dst = new byte[0x10];
        Buffer.BlockCopy(src, 1, dst, 0, 0x10);
        byte[] buffer3 = new byte[0x20];
        Buffer.BlockCopy(src, 0x11, buffer3, 0, 0x20);
        using(Rfc2898DeriveBytes bytes = new Rfc2898DeriveBytes(providedPassword, dst, 0x3e8))
        {
            buffer4 = bytes.GetBytes(0x20);
        }
        return ByteArraysEqual(buffer3, buffer4);
    }

    [MethodImpl(MethodImplOptions.NoOptimization)]
    private bool ByteArraysEqual(byte[] a, byte[] b)
    {
        if (ReferenceEquals(a, b))
        {
            return true;
        }

        if (a == null || b == null || a.Length != b.Length)
        {
            return false;
        }

        bool areSame = true;
        for (int i = 0; i < a.Length; i++)
        {
            areSame &= (a[i] == b[i]);
        }
        return areSame;
    }
}