C# sha256加密驗證

Question

我需要將其轉換為 c# 代碼。 我們正在嘗試在服務器和客戶端之間安全地發送數據包。 我們使用 PHP 進行了此操作，並嘗試將其轉換為 c#。 我是 C# 的新手，很難隱藏此代碼。

function createHashedPayload(string $packet, string $secret, string $hash = 'sha256'): string
{
    return base64_encode(hash_hmac('sha256', $packet, $secret, true) . $packet);
}

function getVerifiedPayload(string $payload, string $secret, string $hash = 'sha256'): ?string
{
    $decoded = base64_decode($payload);
    $hashlen = strlen(hash($hash, "test", true)); // Quick method to get hash length
    

    $hmac = substr($decoded, 0, $hashlen); // Get HMAC from start of string
    $content = substr($decoded, $hashlen); // Rest of the string is content

    // Verify HMAC
    $calcmac = hash_hmac($hash, $content, $secret, true);
    if (hash_equals($hmac, $calcmac)) {
        return $content;
    }

    return null;
}

我能夠隱藏 createHashedPayload

 static string createHashedPayload(string text, string key)
    {
        key = key ?? "";
    
        using (var hmacsha256 = new HMACSHA256(Encoding.UTF8.GetBytes(key)))
        {
            var hash = hmacsha256.ComputeHash(Encoding.UTF8.GetBytes(text));
            return Convert.ToBase64String(hash);
        }
    }

我正在努力將getVerifiedPayload轉換為 c#。 有人可以幫忙嗎？

Answer 1

您可以使用 System.Security.Cryptography 使用密鑰加密字符串，這是您需要的方法

        public static string Encrypt(string plainText, string password)
        {
            if (plainText == null)
            {
                return null;
            }

            if (password == null)
            {
                password = String.Empty;
            }

            // Get the bytes of the string
            var bytesToBeEncrypted = Encoding.UTF8.GetBytes(plainText);
            var passwordBytes = Encoding.UTF8.GetBytes(password);

            // Hash the password with SHA256
            passwordBytes = SHA256.Create().ComputeHash(passwordBytes);

            var bytesEncrypted = Cipher.Encrypt(bytesToBeEncrypted, passwordBytes);

            return Convert.ToBase64String(bytesEncrypted);
        }

並用於解密

public static string Decrypt(string encryptedText, string password)
        {
            if (encryptedText == null)
            {
                return null;
            }

            if (password == null)
            {
                password = String.Empty;
            }

            // Get the bytes of the string
            var bytesToBeDecrypted = Convert.FromBase64String(encryptedText);
            var passwordBytes = Encoding.UTF8.GetBytes(password);

            passwordBytes = SHA256.Create().ComputeHash(passwordBytes);

            var bytesDecrypted = Cipher.Decrypt(bytesToBeDecrypted, passwordBytes);

            return Encoding.UTF8.GetString(bytesDecrypted);
        }