Basic encrypted cookies.

.gitignore

@@ -1,3 +1,6 @@
+KeyInfo.xml
+
+
 # ---> macOS
 # General
 .DS_Store
@@ -5,7 +8,8 @@
 .LSOverride
 
 # Icon must end with two \r
-Icon
+Icon
+
 
 # Thumbnails
 ._*

Pages/Index.cshtml.cs

@@ -11,7 +11,8 @@ namespace StateJobsNYSubmit.Pages
     public class IndexModel : PageModel
     {
         private readonly ILogger<IndexModel> _logger;
-
+        public int counter = 1;
+        private PrivateData p = new PrivateData();
         public IndexModel(ILogger<IndexModel> logger)
         {
             _logger = logger;
@@ -19,7 +20,15 @@ namespace StateJobsNYSubmit.Pages
 
         public void OnGet()
         {
-
+            string cookieValue = Request.Cookies["PrivateData"];
+            if (cookieValue != null) {
+                string test = p.DecryptString(cookieValue);
+                counter = Int32.Parse(test);
+                counter++;
+            }
+            Response.Cookies.Append("PrivateData", p.EncryptString($"{counter}"));
+            Console.WriteLine($"Value of counter: {counter}");
+            
         }
     }
 }

PrivateData.cs

@@ -0,0 +1,57 @@
+using System.Security.Cryptography;
+using System.Text;
+using System.IO;
+using System;
+
+class PrivateData
+{
+    private RSACryptoServiceProvider RSA;
+
+
+    public PrivateData()
+    {
+        RSA = new RSACryptoServiceProvider();
+        RSA.FromXmlString(File.ReadAllText("KeyInfo.xml"));
+    }
+
+    public string EncryptString(string input)
+    {
+        return Encryption(Encoding.UTF8.GetBytes(input), RSA.ExportParameters(false), false);
+    }
+    public string DecryptString(string input)
+    {
+        return Decryption(Convert.FromBase64String(input), RSA.ExportParameters(false), false);
+    }
+    private string Encryption(byte[] Data, RSAParameters RSAKey, bool DoOAEPPadding)
+    {
+        try
+        {
+            Console.WriteLine(RSAKey.ToString());
+            byte[] encryptedData;
+                encryptedData = RSA.Encrypt(Data, DoOAEPPadding);
+
+            return Convert.ToBase64String(encryptedData);
+        }
+        catch (CryptographicException e)
+        {
+            Console.WriteLine(e.Message);
+            return null;
+        }
+    }
+
+    public string Decryption(byte[] Data, RSAParameters RSAKey, bool DoOAEPPadding)
+    {
+        try
+        {
+            byte[] decryptedData;
+                decryptedData = RSA.Decrypt(Data, DoOAEPPadding);
+          
+            return Encoding.UTF8.GetString(decryptedData, 0, decryptedData.Length);  ;
+        }
+        catch (CryptographicException e)
+        {
+            Console.WriteLine(e.ToString());
+            return "";
+        }
+    }
+}