KeyLock Documentation

Complete C# Example

Copy this code into your C# console application to verify license keys:

using System;
using System.Net.Http;
using System.Text;
using System.Text.Json;
using System.Management;
using System.Security.Cryptography;
using System.Threading.Tasks;

namespace KeyLock
{
  // Ready-to-use KeyLock client library
  // Just set your product ID and API key, and you're good to go!
  public class KeyLockClient
  {
      private readonly string _productId;
      private readonly string _apiKey;
      private readonly string _serverUrl;
      private readonly HttpClient _httpClient;

      public KeyLockClient(string productId, string apiKey, string serverUrl = "https://v0-keyauth-like-project.vercel.app")
      {
          _productId = productId;
          _apiKey = apiKey;
          _serverUrl = serverUrl;
          _httpClient = new HttpClient();
      }

      // Verify a license key
      public async Task<LicenseResult> VerifyLicenseAsync(string licenseKey)
      {
          try
          {
              string hwid = GetHardwareId();
              
              var requestData = new
              {
                  licenseKey = licenseKey,
                  productId = _productId,
                  apiKey = _apiKey,
                  hwid = hwid
              };
              
              var json = JsonSerializer.Serialize(requestData);
              var content = new StringContent(json, Encoding.UTF8, "application/json");
              
              var response = await _httpClient.PostAsync($"{_serverUrl}/api/license/verify", content);
              var responseJson = await response.Content.ReadAsStringAsync();
              
              var options = new JsonSerializerOptions { PropertyNameCaseInsensitive = true };
              var result = JsonSerializer.Deserialize<ApiResponse>(responseJson, options);
              
              return new LicenseResult
              {
                  IsValid = result.Valid,
                  Message = result.Message,
                  ExpiresAt = result.ExpiresAt,
                  HardwareId = hwid
              };
          }
          catch (Exception ex)
          {
              return new LicenseResult
              {
                  IsValid = false,
                  Message = $"Error: {ex.Message}"
              };
          }
      }
      
      // Get hardware ID
      public static string GetHardwareId()
      {
          try
          {
              // Get processor ID
              string cpuId = "";
              using (var searcher = new ManagementObjectSearcher("SELECT ProcessorId FROM Win32_Processor"))
              {
                  foreach (var obj in searcher.Get())
                  {
                      cpuId = obj["ProcessorId"].ToString();
                      break;
                  }
              }
              
              // Get motherboard serial number
              string motherboardSerial = "";
              using (var searcher = new ManagementObjectSearcher("SELECT SerialNumber FROM Win32_BaseBoard"))
              {
                  foreach (var obj in searcher.Get())
                  {
                      motherboardSerial = obj["SerialNumber"].ToString();
                      break;
                  }
              }
              
              // Combine hardware identifiers and hash them
              string combinedId = $"{cpuId}|{motherboardSerial}|{Environment.MachineName}";
              using (var sha256 = SHA256.Create())
              {
                  var hashBytes = sha256.ComputeHash(Encoding.UTF8.GetBytes(combinedId));
                  return BitConverter.ToString(hashBytes).Replace("-", "");
              }
          }
          catch
          {
              // Fallback to machine name if hardware info can't be retrieved
              return Environment.MachineName;
          }
      }
      
      // Response classes
      private class ApiResponse
      {
          public bool Success { get; set; }
          public bool Valid { get; set; }
          public string Message { get; set; }
          public string ExpiresAt { get; set; }
      }
  }
  
  public class LicenseResult
  {
      public bool IsValid { get; set; }
      public string Message { get; set; }
      public string ExpiresAt { get; set; }
      public string HardwareId { get; set; }
      
      public int DaysRemaining
      {
          get
          {
              if (string.IsNullOrEmpty(ExpiresAt)) return 0;
              
              try
              {
                  var expiryDate = DateTime.Parse(ExpiresAt);
                  return (int)(expiryDate - DateTime.Now).TotalDays;
              }
              catch
              {
                  return 0;
              }
          }
      }
  }
}

Setup Instructions

// Example usage of the KeyLock client library
using System;
using System.Threading.Tasks;
using KeyLock;

class Program
{
  // Your KeyLock credentials - only these need to be changed!
  private const string PRODUCT_ID = "YOUR_PRODUCT_ID";
  private const string API_KEY = "YOUR_API_KEY";
  
  static async Task Main(string[] args)
  {
      Console.WriteLine("=== KeyLock License Verification ===");
      Console.WriteLine();
      
      // Ask for license key
      Console.Write("Enter your license key: ");
      string licenseKey = Console.ReadLine();
      
      if (string.IsNullOrWhiteSpace(licenseKey))
      {
          Console.WriteLine("License key cannot be empty.");
          Console.WriteLine("Press any key to exit...");
          Console.ReadKey();
          return;
      }

      try
      {
          // Create the KeyLock client
          var client = new KeyLockClient(PRODUCT_ID, API_KEY);
          
          // Verify the license
          Console.WriteLine("Verifying license...");
          var result = await client.VerifyLicenseAsync(licenseKey);
          
          if (result.IsValid)
          {
              Console.ForegroundColor = ConsoleColor.Green;
              Console.WriteLine("✓ License is valid!");
              
              if (!string.IsNullOrEmpty(result.ExpiresAt))
              {
                  Console.WriteLine($"License expires on: {result.ExpiresAt}");
                  Console.WriteLine($"Days remaining: {result.DaysRemaining}");
              }
              
              Console.ResetColor();
          }
          else
          {
              Console.ForegroundColor = ConsoleColor.Red;
              Console.WriteLine("✗ License verification failed!");
              Console.WriteLine($"Reason: {result.Message}");
              Console.ResetColor();
          }
          
          Console.WriteLine($"Hardware ID: {result.HardwareId}");
      }
      catch (Exception ex)
      {
          Console.ForegroundColor = ConsoleColor.Red;
          Console.WriteLine($"Error: {ex.Message}");
          Console.ResetColor();
      }
      
      Console.WriteLine();
      Console.WriteLine("Press any key to exit...");
      Console.ReadKey();
  }
}

1. Create a new C# Console Application in Visual Studio
2. Add the KeyLockClient.cs file to your project (download it from the link above)
3. Install the System.Management NuGet package:
   • Right-click on your project in Solution Explorer
   • Select "Manage NuGet Packages"
   • Search for "System.Management"
   • Install the package
4. Replace YOUR_PRODUCT_ID with your product ID from your products page
5. Replace YOUR_API_KEY with your API key from your profile page
6. Build and run the application