From 5458c9a310a9aa189307565886f5cf97a8d271dd Mon Sep 17 00:00:00 2001
From: Shannon Deminick <sdeminick@gmail.com>
Date: Tue, 15 Jan 2013 01:35:10 +0300
Subject: [PATCH] Adds Encryption/Decryption string extension methods that work
 in medium trust, with unit tests.

---
 src/Umbraco.Core/StringExtensions.cs       | 23 ++++++++++++++++++++++
 src/Umbraco.Tests/StringExtensionsTests.cs | 10 ++++++++++
 2 files changed, 33 insertions(+)

diff --git a/src/Umbraco.Core/StringExtensions.cs b/src/Umbraco.Core/StringExtensions.cs
index 30634e75d1..3250a21d24 100644
--- a/src/Umbraco.Core/StringExtensions.cs
+++ b/src/Umbraco.Core/StringExtensions.cs
@@ -9,6 +9,7 @@ using System.Security.Cryptography;
 using System.Text;
 using System.Text.RegularExpressions;
 using System.Web;
+using System.Web.Security;
 
 namespace Umbraco.Core
 {
@@ -18,6 +19,28 @@ namespace Umbraco.Core
     ///</summary>
     public static class StringExtensions
     {
+		/// <summary>
+		/// Encrypt the string using the MachineKey in medium trust
+		/// </summary>
+		/// <param name="toEncrypt"></param>
+		/// <returns></returns>
+		public static string EncryptWithMachineKey(this string toEncrypt)
+		{
+			var output = FormsAuthentication.Encrypt(new FormsAuthenticationTicket(0, "temp", DateTime.Now, DateTime.MaxValue, false, toEncrypt));
+			return output;
+		}
+
+		/// <summary>
+		/// Decrypt the encrypted string using the Machine key in medium trust
+		/// </summary>
+		/// <param name="encrypted"></param>
+		/// <returns></returns>
+		public static string DecryptWithMachineKey(this string encrypted)
+		{
+			var output = FormsAuthentication.Decrypt(encrypted);
+			return output.UserData;
+		}
+
 		//this is from SqlMetal and just makes it a bit of fun to allow pluralisation
 		public static string MakePluralName(this string name)
 		{
diff --git a/src/Umbraco.Tests/StringExtensionsTests.cs b/src/Umbraco.Tests/StringExtensionsTests.cs
index 49f8f830d7..c00b3cebac 100644
--- a/src/Umbraco.Tests/StringExtensionsTests.cs
+++ b/src/Umbraco.Tests/StringExtensionsTests.cs
@@ -10,6 +10,16 @@ namespace Umbraco.Tests
 	[TestFixture]
     public class StringExtensionsTests
     {
+
+		[TestCase("This is a string to encrypt")]		
+		public void Encrypt_And_Decrypt(string input)
+		{
+			var encrypted = input.EncryptWithMachineKey();
+			var decrypted = encrypted.DecryptWithMachineKey();
+			Assert.AreNotEqual(input, encrypted);
+			Assert.AreEqual(input, decrypted);
+		}
+
         [TestCase("Hello this is my string", " string", "Hello this is my")]
         [TestCase("Hello this is my string strung", " string", "Hello this is my string strung")]
         [TestCase("Hello this is my string string", " string", "Hello this is my")]