C#对文件进行加密解密代码

 using System; using System.IO; using System.Security.Cryptography; public class Example19_9 { public static void Main() { // Create a new file to work with FileStream fsOut = File.Create(@"c:\temp\encrypted.txt"); // Create a new crypto provider TripleDESCryptoServiceProvider tdes = new TripleDESCryptoServiceProvider(); // Create a cryptostream to encrypt to the filestream CryptoStream cs = new CryptoStream(fsOut, tdes.CreateEncryptor(), CryptoStreamMode.Write); // Create a StreamWriter to format the output StreamWriter sw = new StreamWriter(cs); // And write some data sw.WriteLine("'Twas brillig, and the slithy toves"); sw.WriteLine("Did gyre and gimble in the wabe."); sw.Flush(); sw.Close(); // save the key and IV for future use FileStream fsKeyOut = File.Create(@"c:\\temp\encrypted.key"); // use a BinaryWriter to write formatted data to the file BinaryWriter bw = new BinaryWriter(fsKeyOut); // write data to the file bw.Write( tdes.Key ); bw.Write( tdes.IV ); // flush and close bw.Flush(); bw.Close(); } } 

 using System; using System.IO; using System.Security.Cryptography; public class Example19_10 { public static void Main() { // Create a new crypto provider TripleDESCryptoServiceProvider tdes = new TripleDESCryptoServiceProvider(); // open the file containing the key and IV FileStream fsKeyIn = File.OpenRead(@"c:\temp\encrypted.key"); // use a BinaryReader to read formatted data from the file BinaryReader br = new BinaryReader(fsKeyIn); // read data from the file and close it tdes.Key = br.ReadBytes(24); tdes.IV = br.ReadBytes(8); // Open the encrypted file FileStream fsIn = File.OpenRead(@"c:\\temp\\encrypted.txt"); // Create a cryptostream to decrypt from the filestream CryptoStream cs = new CryptoStream(fsIn, tdes.CreateDecryptor(), CryptoStreamMode.Read); // Create a StreamReader to format the input StreamReader sr = new StreamReader(cs); // And decrypt the data Console.WriteLine(sr.ReadToEnd()); sr.Close(); } }