Click here to Skip to main content
Click here to Skip to main content
Add your own
alternative version

Enhanced String Handling II

, 16 Dec 2010
Overcoming limitations of: Enhanced String Handling
EnhancedStringEvaluate.zip
EnhancedStringEvaluate
bin
Debug
ConfigEvaluate.vshost.exe
ConfigEvaluate.vshost.exe.manifest
EnhancedStringEvaluate.dll
EnhancedStringEvaluate.pdb
ConcordPairEvaluate.csproj.vs10x
EnhancedStringEvaluate.csproj.user
EnhancedStringEvaluate.csproj.vs10x
obj
Debug
Decl
EnhancedStringEvaluate.dll
EnhancedStringEvaluate.pdb
DesignTimeResolveAssemblyReferencesInput.cache
EnhancedStringEvaluate.dll
EnhancedStringEvaluate.pdb
Refactor
ConfigEvaluate.dll
ResolveAssemblyReference.cache
TempPE
Properties
EvaluateTest
bin
Debug
EnhancedStringEvaluate.dll
EnhancedStringEvaluate.pdb
EvaluateSampleTest.dll
EvaluateSampleTest.pdb
EvaluateTest.dll
EvaluateTest.pdb
TestEvaluation.exe
TestEvaluation.pdb
EvaluateSampleTest.csproj.vs10x
EvaluateTest.csproj.vs10x
obj
Debug
Decl
EvaluateSampleTest.dll
EvaluateSampleTest.pdb
DesignTimeResolveAssemblyReferencesInput.cache
EvaluateSampleTest.dll
EvaluateSampleTest.pdb
EvaluateTest.dll
EvaluateTest.pdb
ResolveAssemblyReference.cache
TempPE
Properties
TestEvaluate
bin
Debug
abc.text
EnhancedStringEvaluate.dll
EnhancedStringEvaluate.pdb
TestEvaluate.exe
TestEvaluate.pdb
TestEvaluate.vshost.exe.manifest
TestEvaluation.exe
TestEvaluation.pdb
TestEvaluation.vshost.exe
TestEvaluation.vshost.exe.manifest
TestOnTheFlyConfig.vshost.exe
TestOnTheFlyConfig.vshost.exe.manifest
obj
Debug
Decl
TestEvaluation.exe
TestEvaluation.pdb
DesignTimeResolveAssemblyReferencesInput.cache
Refactor
ResolveAssemblyReference.cache
TempPE
TestEvaluate.exe
TestEvaluate.pdb
TestEvaluation.exe
TestEvaluation.pdb
ProcessEvaluate
Properties
TestEvaluate.csproj.vs10x
TestEvaluation.csproj.user
TestEvaluation.csproj.vs10x
TestOnTheFlyConfig.csproj.vs10x
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using EnhancedStringEvaluate;
using System.Security.Cryptography;
using System.IO;
using System.Text.RegularExpressions;


namespace TestEvaluation.ProcessEvaluate
{
	/// <summary>
	/// Purpose:
	///		Can be used for strings you need to publish yet protected.  
	///		Like database connection string in a configuration file.
	///	
	/// Format:
	///		{Decrypt::encrypted-string}
	/// </summary>
	public class ProcessDecrypt : IProcessEvaluate
	{
		private readonly TripleDESCryptoServiceProvider _tDes;
		private readonly IDelimitersAndSeparator _delim;
		private readonly Regex _reDecript;

		public ProcessDecrypt() : this(DelimitersAndSeparator.DefaultDelimitedString) { }
		public ProcessDecrypt(IDelimitersAndSeparator delim, byte[] key = null, byte[] iv = null)
		{
			_tDes = new TripleDESCryptoServiceProvider();
			_tDes.Key = key;
			if (key == null)
				_tDes.Key = Array.ConvertAll<byte, byte>(_tDes.Key, b => (byte)(((int)b + 7) % ((int)byte.MaxValue + 1)));

			_tDes.IV = iv;
			if (iv == null)
				_tDes.IV = Array.ConvertAll<byte, byte>(_tDes.IV, b => (byte)(((int)b - 7) % ((int)byte.MaxValue + 1)));

			_delim = delim;

			RegexOptions reo = RegexOptions.Singleline | RegexOptions.IgnoreCase;
			string pattern = @"({)\s*Decrypt\s*::()(})";
		}

		#region IProcessEvaluate Members

		public void Evaluate(object src, EnhancedStringEventArgs ea)
		{
			throw new NotImplementedException();
		}

		#endregion

		/// <summary>
		/// Decrypt encrypted text
		/// </summary>
		/// <param name="sEncripted"></param>
		/// <returns></returns>
		private string DecryptTextFromMemory(string sEncripted)
		{
			try
			{
				byte[] Data = new ASCIIEncoding().GetBytes(sEncripted);
				using (var msDecrypt = new MemoryStream(Data))
				{
					var csDecrypt = new CryptoStream(msDecrypt, _tDes.CreateDecryptor(), CryptoStreamMode.Read);

					byte[] fromEncrypt = new byte[Data.Length];
					csDecrypt.Read(fromEncrypt, 0, fromEncrypt.Length);
					return new ASCIIEncoding().GetString(fromEncrypt);
				}
			}
			catch (CryptographicException e)
			{
				Console.WriteLine("A Cryptographic error occurred: {0}", e.Message);
				return null;
			}
		}

		/// <summary>
		/// Give the ability to encript text
		/// </summary>
		/// <param name="text"></param>
		/// <returns></returns>
		public string EncryptTextToMemory(string text)
		{
			try
			{
				byte[] ret;
				using (var mStream = new MemoryStream())
				using (var cStream = new CryptoStream(mStream, _tDes.CreateEncryptor(), CryptoStreamMode.Write))
				{
					byte[] toEncrypt = new ASCIIEncoding().GetBytes(text);
					cStream.Write(toEncrypt, 0, toEncrypt.Length);
					cStream.FlushFinalBlock();
					ret = mStream.ToArray();
				}

				return new ASCIIEncoding().GetString(ret);
			}
			catch (CryptographicException e)
			{
				Console.WriteLine("A Cryptographic error occurred: {0}", e.Message);
				return null;
			}
		}
	}
}

By viewing downloads associated with this article you agree to the Terms of Service and the article's licence.

If a file you wish to view isn't highlighted, and is a text file (not binary), please let us know and we'll add colourisation support for it.

License

This article, along with any associated source code and files, is licensed under The Code Project Open License (CPOL)

Share

About the Author

Avi Farah

United States United States
avifarah@gmail.com

| Advertise | Privacy | Mobile
Web04 | 2.8.140827.1 | Last Updated 16 Dec 2010
Article Copyright 2010 by Avi Farah
Everything else Copyright © CodeProject, 1999-2014
Terms of Service
Layout: fixed | fluid