匹配签名哈希以匹配应用程序代码中的哈希以进行单元测试

Question

我有一个端点，它在标头中接收带有timestamp和signature值的payload 。 除此之外，我还有一个保存在别处的SecretKey 。

为了验证有效负载来自受信任的来源，我执行以下操作：

public bool Authenticate(payload, timestamp, signature)
{
    // concat the timestamp header value with the serialized payload
    var stringified = string.Concat(timestamp, JsonConvert.SerializeObject(payload));

    // retrieve secret key
    string secretKey = getSecretKey();

    // compute hash
    var hash = new HMACSHA256(secretKey.ConvertStringToByteArray());
    var output = hash.ComputeHash(valueToDigest.ConvertStringToByteArray());

    return output == signature.ConvertStringToByteArray();
}

// an extension method I wrote that converts the string to Byte[]
public static Byte[] ConvertStringToByteArray(this string input)
{
    var encoding = new UTF8Encoding();
    return encoding.GetBytes(input);
}

在我的测试中，如何获取负载标头中包含的哈希（ signature ）以匹配我使用secretKey计算的哈希，以便满足return output == signature.ConvertStringToByteArray()条件？

编辑：更新的方法

public bool Authenticate(MyData payload, string timestamp, string signature)
{
    // concat the timestamp header value with the serialized payload
    var stringified = string.Concat(timestamp, JsonConvert.SerializeObject(payload));

    // retrieve secret key
    string secretKey = getSecretKey();

    // compute hash
    var hash = GetAuthHash(stringified, secretKey);

    // do string comparison on the hash and the signature
    return hash == signature;
}

public class MyData 
{
    public string id {get;set;}
    public string name {get;set;}
}

public string GetAuthHash(string message, string secret)
{
    var encoding = new UTF8Encoding();

    byte[] keyByte = encoding.GetBytes(secret);
    byte[] messageBytes = encoding.GetBytes(message);
    
    using (var hmacsha256 = new HMACSHA256(keyByte))
    {
        byte[] hashmessage = hmacsha256.ComputeHash(messageBytes);
        return Convert.ToBase64String(hashmessage);
    }
}