zengzy / rps · Files

using System.Security.Cryptography;

namespace RobotProductionSystem.Api.Services;

public static class PasswordHasher
{
    private const int Iterations = 100_000;
    private const int SaltSize = 16;
    private const int KeySize = 32;

    public static string Hash(string password)
    {
        var salt = RandomNumberGenerator.GetBytes(SaltSize);
        var key = Rfc2898DeriveBytes.Pbkdf2(password, salt, Iterations, HashAlgorithmName.SHA256, KeySize);
        return $"pbkdf2-sha256${Iterations}${Convert.ToBase64String(salt)}${Convert.ToBase64String(key)}";
    }

    public static bool Verify(string password, string hash)
    {
        var parts = hash.Split('$');
        if (parts.Length != 4 || parts[0] != "pbkdf2-sha256" || !int.TryParse(parts[1], out var iterations))
        {
            return false;
        }

        var salt = Convert.FromBase64String(parts[2]);
        var expected = Convert.FromBase64String(parts[3]);
        var actual = Rfc2898DeriveBytes.Pbkdf2(password, salt, iterations, HashAlgorithmName.SHA256, expected.Length);
        return CryptographicOperations.FixedTimeEquals(actual, expected);
    }
}