C#实现对文件进行加密解密的方法

本文实例讲述了c#实现对文件进行加密解密的方法。分享给大家供大家参考。具体如下：

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();
 }
}

解密代码如下：

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();
 }
}

希望本文所述对大家的c#程序设计有所帮助。