DigitalPlatform.Text.cs

//test
using System;
using System.IO;
using System.Xml;
using System.Text;
using System.Collections;
using System.Collections.Generic;
using System.Threading;
using System.Globalization;
using System.Text.RegularExpressions;
using System.Security.Cryptography;
using System.Diagnostics;
using System.Web;

namespace DigitalPlatform.Text
{
	
	public class EncodingUtil 
	{
		public static string DecodeBase64(string strBase64)
		{
			byte[] baText = Convert.FromBase64String(strBase64);

			return Encoding.UTF8.GetString(baText);
		}

		public static string EncodeBase64(string strText)
		{
			byte[] baText = Encoding.UTF8.GetBytes(strText);
			return Convert.ToBase64String(baText);
		}
	}

#if REMOVED
	// 类 Cryptography 已经移动到了 DigitalPlatform.Core.dll 中

	/// <summary>
	/// 和加密有关的函数
	/// </summary>
	public class Cryptography
	{
		// 由于获得的结果byte[] 中可能包含不可显示的字符，所以用base64编码为字符串
		static public string GetSHA1(string strPlainText)
		{
			byte[] source = Encoding.UTF8.GetBytes(strPlainText);
			byte[] result = null; 
 
			SHA1 sha = new SHA1CryptoServiceProvider(); 
			// This is one implementation of the abstract class SHA1.
			result = sha.ComputeHash(source);
			return Convert.ToBase64String(result);
		}


		/// <remarks>
		/// Depending on the legal key size limitations of a specific CryptoService provider
		/// and length of the private key provided, padding the secret key with space character
		/// to meet the legal size of the algorithm.
		/// </remarks>
		private static byte[] GetLegalKey(string Key)
		{

			//具有随机密钥的 DES 实例
			DESCryptoServiceProvider des = new DESCryptoServiceProvider();


			int len = des.LegalKeySizes[0].MinSize / 8;

			string sTemp = Key;

			if (sTemp.Length > len)
				sTemp = sTemp.Substring(0, len);

			else 
			{

				while(sTemp.Length < len)
					sTemp += ' ';
			}

			// convert the secret key to byte array
			return ASCIIEncoding.ASCII.GetBytes(sTemp);
		}

		public static string Encrypt(string strSource, string strKey)
		{
			Byte[] baInput = Encoding.Unicode.GetBytes(strSource);

			//具有随机密钥的 DES 实例
			DESCryptoServiceProvider des = new DESCryptoServiceProvider();

			byte[] bytKey = GetLegalKey(strKey);

			// set the private key
			des.Key = bytKey;
			des.IV = bytKey;

			//从此实例创建 DES 加密器
			ICryptoTransform desencrypt = des.CreateEncryptor();

			Byte[] baOutput = desencrypt.TransformFinalBlock(baInput, 0, baInput.Length);

			return Convert.ToBase64String(baOutput);
		}

		public static string Decrypt(string strSource, string strKey)
		{
			byte[] baInput = Convert.FromBase64String(strSource);
			//具有随机密钥的 DES 实例
			DESCryptoServiceProvider des = new DESCryptoServiceProvider();

			byte[] bytKey = GetLegalKey(strKey);

			// set the private key
			des.Key = bytKey;
			des.IV = bytKey;

			//从此 des 实例创建 DES 解密器
			ICryptoTransform desdecrypt = des.CreateDecryptor();
			Byte[] baOutput = desdecrypt.TransformFinalBlock(baInput, 0, baInput.Length);
			return Encoding.Unicode.GetString(baOutput);
		}


	}

#endif
}