请问怎么利用C#对文本文件加密

Question

我使用文本文档保存了登陆时候的用户名和密码，请问怎么把这个文本进行加密，在线等啊，希望高手指点

Answer 1

C#一个封装的加密解密类
using System;
using System.Text;
using System.Globalization;
using System.Security.Cryptography;
using System.Windows.Forms;namespace Jh.Encrypts
{
public class JhEncrypt
{
/// <summary>
/// 构造方法
/// </summary>
public JhEncrypt()
{
}
/// <summary>
/// 使用缺省密钥字符串加密
/// </summary>
/// <param name="original">明文</param>
/// <returns>密文</returns>
public static string Encrypt(string original)
{
return Encrypt(original,"JASONHEUNG");
}
/// <summary>
/// 使用缺省密钥解密
/// </summary>
/// <param name="original">密文</param>
/// <returns>明文</returns>
public static string Decrypt(string original)
{
return Decrypt(original,"JASONHEUNG",System.Text.Encoding.Default);
}
/// <summary>
/// 使用给定密钥解密
/// </summary>
/// <param name="original">密文</param>
/// <param name="key">密钥</param>
/// <returns>明文</returns>
public static string Decrypt(string original, string key)
{
return Decrypt(original,key,System.Text.Encoding.Default);
}
/// <summary>
/// 使用缺省密钥解密,返回指定编码方式明文
/// </summary>
/// <param name="original">密文</param>
/// <param name="encoding">编码方式</param>
/// <returns>明文</returns>
public static string Decrypt(string original,Encoding encoding)
{
return Decrypt(original,"JASONHEUNG",encoding);
}
/// <summary>
/// 使用给定密钥加密
/// </summary>
/// <param name="original">原始文字</param>
/// <param name="key">密钥</param>
/// <param name="encoding">字符编码方案</param>
/// <returns>密文</returns>
public static string Encrypt(string original, string key)
{
byte[] buff = System.Text.Encoding.Default.GetBytes(original);
byte[] kb = System.Text.Encoding.Default.GetBytes(key);
return Convert.ToBase64String(Encrypt(buff,kb));
}/// <summary>
/// 使用给定密钥解密
/// </summary>
/// <param name="encrypted">密文</param>
/// <param name="key">密钥</param>
/// <param name="encoding">字符编码方案</param>
/// <returns>明文</returns>
public static string Decrypt(string encrypted, string key,Encoding encoding)
{
byte[] buff = Convert.FromBase64String(encrypted);
byte[] kb = System.Text.Encoding.Default.GetBytes(key);
return encoding.GetString(Decrypt(buff,kb));
}
/// <summary>
/// 生成MD5摘要
/// </summary>
/// <param name="original">数据源</param>
/// <returns>摘要</returns>
public static byte[] MakeMD5(byte[] original)
{
MD5CryptoServiceProvider hashmd5 = new MD5CryptoServiceProvider();
byte[] keyhash = hashmd5.ComputeHash(original);
hashmd5 = null;
return keyhash;
}/// <summary>
/// 使用给定密钥加密
/// </summary>
/// <param name="original">明文</param>
/// <param name="key">密钥</param>
/// <returns>密文</returns>
public static byte[] Encrypt(byte[] original, byte[] key)
{
TripleDESCryptoServiceProvider des = new TripleDESCryptoServiceProvider();
des.Key = MakeMD5(key);
des.Mode = CipherMode.ECB;return des.CreateEncryptor().TransformFinalBlock(original, 0, original.Length);
}/// <summary>
/// 使用给定密钥解密数据
/// </summary>
/// <param name="encrypted">密文</param>
/// <param name="key">密钥</param>
/// <returns>明文</returns>
public static byte[] Decrypt(byte[] encrypted, byte[] key)
{
TripleDESCryptoServiceProvider des = new TripleDESCryptoServiceProvider();
des.Key = MakeMD5(key);
des.Mode = CipherMode.ECB;return des.CreateDecryptor().TransformFinalBlock(encrypted, 0, encrypted.Length);
}/// <summary>
/// 使用给定密钥加密
/// </summary>
/// <param name="original">原始数据</param>
/// <param name="key">密钥</param>
/// <returns>密文</returns>
public static byte[] Encrypt(byte[] original)
{
byte[] key = System.Text.Encoding.Default.GetBytes("JASONHEUNG");
return Encrypt(original,key);
}/// <summary>
/// 使用缺省密钥解密数据
/// </summary>
/// <param name="encrypted">密文</param>
/// <param name="key">密钥</param>
/// <returns>明文</returns>
public static byte[] Decrypt(byte[] encrypted)
{
byte[] key = System.Text.Encoding.Default.GetBytes("JASONHEUNG");
return Decrypt(encrypted,key);
}}
}

Answer 2

第二种public sealed class Cryption
  {
//members of the Cryption 
//algorithm type in my case it’s RijndaelManaged
    private RijndaelManaged Algorithm;
//memory stream
    private MemoryStream memStream;
//ICryptoTransform interface
    private ICryptoTransform EncryptorDecryptor;
//CryptoStream
    private CryptoStream crStream;
//Stream writer and Stream reader
    private StreamWriter strWriter;
    private StreamReader strReader;
//internal members
    private string m_key;
    private string m_iv;
//the Key and the Inicialization Vector
    private byte[] key;
    private byte[] iv;
//password view
    private string pwd_str;
    private byte[] pwd_byte;
//Constructor
    public Cryption(string key_val, string iv_val)
    {
      key = new byte[32];
      iv = new byte[32];      int i;
      m_key = key_val;
      m_iv = iv_val;
//key calculation, depends on first constructor parameter
      for(i=0;i < m_key.Length;i++)
      {
        key[i] = Convert.ToByte(m_key[i]);
      }
//IV calculation, depends on second constructor parameter
      for(i=0;i < m_iv.Length;i++)
      {
        iv[i] = Convert.ToByte(m_iv[i]);
      }    }
//Encrypt method implementation
    public string Encrypt(string s)
    {
//new instance of algorithm creation
      Algorithm = new RijndaelManaged();//setting algorithm bit size
      Algorithm.BlockSize = 256;
      Algorithm.KeySize = 256;//creating new instance of Memory stream
      memStream = new MemoryStream();//creating new instance of the Encryptor
      EncryptorDecryptor = Algorithm.CreateEncryptor(key,iv);//creating new instance of CryptoStream
      crStream = new CryptoStream(memStream, EncryptorDecryptor, 
      CryptoStreamMode.Write);//creating new instance of Stream Writer
      strWriter = new StreamWriter(crStream);//cipher input string
      strWriter.Write(s);//clearing buffer for currnet writer and writing any 
//buffered data to //the underlying device
      strWriter.Flush();
      crStream.FlushFinalBlock();//storing cipher string as byte array 
      pwd_byte = new byte[memStream.Length];
      memStream.Position = 0;
      memStream.Read(pwd_byte,0,(int)pwd_byte.Length);//storing cipher string as Unicode string
      pwd_str = new UnicodeEncoding().GetString(pwd_byte);      return pwd_str;
    }//Decrypt method implementation 
    public string Decrypt(string s)
    {
//new instance of algorithm creation
      Algorithm = new RijndaelManaged();//setting algorithm bit size
      Algorithm.BlockSize = 256;
      Algorithm.KeySize = 256;//creating new Memory stream as stream for input string      
MemoryStream memStream = new MemoryStream(
   new UnicodeEncoding().GetBytes(s));//Decryptor creating 
      ICryptoTransform EncryptorDecryptor = 
          Algorithm.CreateDecryptor(key,iv);//setting memory stream position
      memStream.Position = 0;//creating new instance of Crupto stream
      CryptoStream crStream = new CryptoStream(
          memStream,EncryptorDecryptor,CryptoStreamMode.Read);//reading stream
      strReader = new StreamReader(crStream);//returnig decrypted string
      return strReader.ReadToEnd();
    }
  }调用方法：
Cryptography.Cryption Cryption = new Cryptography.Cryption(
  "Your key","Your vector");

Answer 3

何必自己写,有现成的不用?
String 密文 = System.Web.Security.FormsAuthentication.HashPasswordForStoringInConfigFile(你的文本, "MD5");或String 密文 = System.Web.Security.FormsAuthentication.HashPasswordForStoringInConfigFile(你的文本, "SHA1");

Answer 4

这个方法,看 方法名称就知道它就是干你要的这事的.HashPasswordForStoringInConfigFileHash-Password-For-Storing-In-Config-File  扰乱 密码 为了 存储 在配置文件里 ......

Answer 5

http://www.ccsharp.net/list.aspx?bid=48

Answer 6

/// <summary>
        /// 加密指定的文件,如果成功返回True,否则false
        /// </summary>
        /// <param name="filePath">要加密的文件路径</param>
        /// <param name="outPath">加密后的文件输出路径</param>
        public void EncryptFile(string filePath, string outPath)
        {
            bool isExist = File.Exists(filePath);
            if (isExist)//如果存在
            {
                byte[] ivb = Encoding.ASCII.GetBytes(this.iv);
                byte[] keyb = Encoding.ASCII.GetBytes(this.EncryptKey);
                //得到要加密文件的字节流
                FileStream fin = new FileStream(filePath, FileMode.Open, FileAccess.Read);
                StreamReader reader = new StreamReader(fin, this.EncodingMode);
                string dataStr = reader.ReadToEnd();
                byte[] toEncrypt = this.EncodingMode.GetBytes(dataStr);
                fin.Close();                FileStream fout = new FileStream(outPath, FileMode.Create, FileAccess.Write);
                ICryptoTransform encryptor = des.CreateEncryptor(keyb, ivb);
                CryptoStream csEncrypt = new CryptoStream(fout, encryptor, CryptoStreamMode.Write);
                try
                {
                    //加密得到的文件字节流
                    csEncrypt.Write(toEncrypt, 0, toEncrypt.Length);
                    csEncrypt.FlushFinalBlock();
                }
                catch (Exception err)
                {
                    throw new ApplicationException(err.Message);
                }
                finally
                {
                    try
                    {
                        fout.Close();
                        csEncrypt.Close();
                    }
                    catch
                    {
                        ;
                    }
                }
            }
            else
            {
                throw new FileNotFoundException("没有找到指定的文件");
            }
        }

Answer 7

/// <summary>
        /// 解密指定的文件
        /// </summary>
        /// <param name="filePath">要解密的文件路径</param>
        /// <param name="outPath">解密后的文件输出路径</param>
        public void DecryptFile(string filePath, string outPath)
        {
            bool isExist = File.Exists(filePath);
            if (isExist)//如果存在
            {
                byte[] ivb = Encoding.ASCII.GetBytes(this.iv);
                byte[] keyb = Encoding.ASCII.GetBytes(this.EncryptKey);
                FileInfo file = new FileInfo(filePath);
                byte[] deCrypted = new byte[file.Length];
                //得到要解密文件的字节流
                FileStream fin = new FileStream(filePath, FileMode.Open, FileAccess.Read);
                //解密文件
                try
                {
                    ICryptoTransform decryptor = des.CreateDecryptor(keyb, ivb);
                    CryptoStream csDecrypt = new CryptoStream(fin, decryptor, CryptoStreamMode.Read);
                    csDecrypt.Read(deCrypted, 0, deCrypted.Length);
                }
                catch (Exception err)
                {
                    throw new ApplicationException(err.Message);
                }
                finally
                {
                    try
                    {
                        fin.Close();
                    }
                    catch { ;}
                }
                FileStream fout = new FileStream(outPath, FileMode.Create, FileAccess.Write);
                fout.Write(deCrypted, 0, deCrypted.Length);
                fout.Close();
            }
            else
            {
                throw new FileNotFoundException("指定的解密文件没有找到");
            }
        }

Answer 8

http://support.microsoft.com/default.aspx?scid=kb%3Bzh-cn%3B307010