.net内核中的KeyedHashAlgorithm

using System;
using System.Security.Cryptography;
using System.Text;

public class HmacExample
{
    public static byte[] ComputeHmac(string data, string key)
    {
        using (var hmac = new HMACSHA256(Encoding.UTF8.GetBytes(key)))
        {
            return hmac.ComputeHash(Encoding.UTF8.GetBytes(data));
        }
    }

    public static bool VerifyHmac(string data, string key, byte[] hmacToVerify)
    {
        var computedHmac = ComputeHmac(data, key);
        return SlowEquals(computedHmac, hmacToVerify);
    }

    private static bool SlowEquals(byte[] a, byte[] b)
    {
        uint diff = (uint)a.Length ^ (uint)b.Length;
        for (int i = 0; i < a.Length && i < b.Length; i++)
        {
            diff |= (uint)(a[i] ^ b[i]);
        }
        return diff == 0;
    }
}

class Program
{
    static void Main()
    {
        string secretKey = "mySecretKey";
        string message = "Hello, World!";

        byte[] hmac = HmacExample.ComputeHmac(message, secretKey);
        Console.WriteLine("HMAC: " + BitConverter.ToString(hmac).Replace("-", ""));

        bool isValid = HmacExample.VerifyHmac(message, secretKey, hmac);
        Console.WriteLine("HMAC Verification: " + isValid);
    }
}