学步园

using System;<br /> using System.Collections.Generic;<br /> using System.Text;<br /> using System.IO;<br /> using System.Security;<br /> using System.Security.Cryptography;<br /> /*----------------------------------------------<br /> * DES加密、解密类库，字符串加密结果使用BASE64编码返回，支持文件的加密和解密<br /> * 作者： 三角猫/DeltaCat<br /> * 网址： http://www.zu14.cn<br /> * 转载务必保留此信息<br /> * ---------------------------------------------<br /> */<br /> namespace ZU14<br /> {<br /> public sealed class DES<br /> {<br /> string iv = "1234的yzo";<br /> string key = "123在yzo";<br /> /// <summary><br /> /// DES加密偏移量，必须是>=8位长的字符串<br /> /// </summary><br /> public string IV<br /> {<br /> get { return iv; }<br /> set { iv = value; }<br /> }<br /> /// <summary><br /> /// DES加密的私钥，必须是8位长的字符串<br /> /// </summary><br /> public string Key<br /> {<br /> get { return key; }<br /> set { key = value; }<br /> }<br /> /// <summary><br /> /// 对字符串进行DES加密<br /> /// </summary><br /> /// <param name="sourceString">待加密的字符串</param><br /> /// <returns>加密后的BASE64编码的字符串</returns><br /> public string Encrypt(string sourceString)<br /> {<br /> byte[] btKey = Encoding.Default.GetBytes(key);<br /> byte[] btIV = Encoding.Default.GetBytes(iv);<br /> DESCryptoServiceProvider des = new DESCryptoServiceProvider();<br /> using (MemoryStream ms = new MemoryStream())<br /> {<br /> byte[] inData = Encoding.Default.GetBytes(sourceString);<br /> try<br /> {<br /> using (CryptoStream cs = new CryptoStream(ms, des.CreateEncryptor(btKey, btIV), CryptoStreamMode.Write))<br /> {<br /> cs.Write(inData, 0, inData.Length);<br /> cs.FlushFinalBlock();<br /> }<br /> return Convert.ToBase64String(ms.ToArray());<br /> }<br /> catch<br /> {<br /> throw;<br /> }<br /> }<br /> }<br /> /// <summary><br /> /// 对DES加密后的字符串进行解密<br /> /// </summary><br /> /// <param name="encryptedString">待解密的字符串</param><br /> /// <returns>解密后的字符串</returns><br /> public string Decrypt(string encryptedString)<br /> {<br /> byte[] btKey = Encoding.Default.GetBytes(key);<br /> byte[] btIV = Encoding.Default.GetBytes(iv);<br /> DESCryptoServiceProvider des = new DESCryptoServiceProvider();<br /> using (MemoryStream ms = new MemoryStream())<br /> {<br /> byte[] inData = Convert.FromBase64String(encryptedString);<br /> try<br /> {<br /> using (CryptoStream cs = new CryptoStream(ms, des.CreateDecryptor(btKey, btIV), CryptoStreamMode.Write))<br /> {<br /> cs.Write(inData, 0, inData.Length);<br /> cs.FlushFinalBlock();<br /> }<br /> return Encoding.Default.GetString(ms.ToArray());<br /> }<br /> catch<br /> {<br /> throw;<br /> }<br /> }<br /> }<br /> /// <summary><br /> /// 对文件内容进行DES加密<br /> /// </summary><br /> /// <param name="sourceFile">待加密的文件绝对路径</param><br /> /// <param name="destFile">加密后的文件保存的绝对路径</param><br /> public void EncryptFile(string sourceFile, string destFile)<br /> {<br /> if (!File.Exists(sourceFile)) throw new FileNotFoundException("指定的文件路径不存在！", sourceFile);<br /> byte[] btKey = Encoding.Default.GetBytes(key);<br /> byte[] btIV = Encoding.Default.GetBytes(iv);<br /> DESCryptoServiceProvider des = new DESCryptoServiceProvider();<br /> byte[] btFile = File.ReadAllBytes(sourceFile);<br /> using (FileStream fs = new FileStream(destFile, FileMode.Create, FileAccess.Write))<br /> {<br /> try<br /> {<br /> using (CryptoStream cs = new CryptoStream(fs, des.CreateEncryptor(btKey, btIV), CryptoStreamMode.Write))<br /> {<br /> cs.Write(btFile, 0, btFile.Length);<br /> cs.FlushFinalBlock();<br /> }<br /> }<br /> catch<br /> {<br /> throw;<br /> }<br /> finally<br /> {<br /> fs.Close();<br /> }<br /> }<br /> }<br /> /// <summary><br /> /// 对文件内容进行DES加密，加密后覆盖掉原来的文件<br /> /// </summary><br /> /// <param name="sourceFile">待加密的文件的绝对路径</param><br /> public void EncryptFile(string sourceFile)<br /> {<br /> EncryptFile(sourceFile, sourceFile);<br /> }<br /> /// <summary><br /> /// 对文件内容进行DES解密<br /> /// </summary><br /> /// <param name="sourceFile">待解密的文件绝对路径</param><br /> /// <param name="destFile">解密后的文件保存的绝对路径</param><br /> public void DecryptFile(string sourceFile, string destFile)<br /> {<br /> if (!File.Exists(sourceFile)) throw new FileNotFoundException("指定的文件路径不存在！", sourceFile);<br /> byte[] btKey = Encoding.Default.GetBytes(key);<br /> byte[] btIV = Encoding.Default.GetBytes(iv);<br /> DESCryptoServiceProvider des = new DESCryptoServiceProvider();<br /> byte[] btFile = File.ReadAllBytes(sourceFile);<br /> using (FileStream fs = new FileStream(destFile, FileMode.Create, FileAccess.Write))<br /> {<br /> try<br /> {<br /> using (CryptoStream cs = new CryptoStream(fs, des.CreateDecryptor(btKey, btIV), CryptoStreamMode.Write))<br /> {<br /> cs.Write(btFile, 0, btFile.Length);<br /> cs.FlushFinalBlock();<br /> }<br /> }<br /> catch<br /> {<br /> throw;<br /> }<br /> finally<br /> {<br /> fs.Close();<br /> }<br /> }<br /> }<br /> /// <summary><br /> /// 对文件内容进行DES解密，加密后覆盖掉原来的文件<br /> /// </summary><br /> /// <param name="sourceFile">待解密的文件的绝对路径</param><br /> public void DecryptFile(string sourceFile)<br /> {<br /> DecryptFile(sourceFile, sourceFile);<br /> }<br /> }<br /> } 

例子：

ZU14.DES des = new ZU14.DES();<br /> des.IV = "abcd哈哈笑";<br /> des.Key = "必须八位";<br /> string es = des.Encrypt("在");<br /> Console.WriteLine(es);<br /> Console.Write(des.Decrypt(es));<br /> des.EncryptFile(@"d:/a.txt", @"d:/b.txt");<br /> des.DecryptFile(@"d:/b.txt");<br /> Console.ReadKey(true); 

本文转自：http://www.zu14.cn/2009/05/26/csharp-des-library-support-file-base64-encoding/