.NET加密技术应用
using System;
using System.Text;
using System.Security;
using System.Security.Cryptography;
using System.IO;
namespace EncryptClasses
{
/// <summary>
/// 此处定义的是DES加密,为了便于今后的管理和维护
/// 请不要随便改动密码,或者改变了密码后请一定要
/// 牢记先前的密码,否则将会照成不可预料的损失
/// </summary>
public class DESEncrypt
{
#region "member fields"
private string iv="12345678";
private string key="12345678";
private Encoding encoding=new UnicodeEncoding();
private DES des;
#endregion
/// <summary>
/// 构造函数
/// </summary>
public DESEncrypt()
{
des=new DESCryptoServiceProvider();
}
#region "propertys"
/// <summary>
/// 设置加密密钥
/// </summary>
public string EncryptKey
{
get{return this.key;}
set
{
this.key=value;
}
}
/// <summary>
/// 要加密字符的编码模式
/// </summary>
public Encoding EncodingMode
{
get{return this.encoding;}
set{this.encoding=value;}
}
#endregion
#region "methods"
/// <summary>
/// 加密字符串并返回加密后的结果
/// </summary>
/// <param name="str"></param>
/// <returns></returns>
public string EncryptString(string str)
{
byte[] ivb=Encoding.ASCII.GetBytes(this.iv);
byte[] keyb=Encoding.ASCII.GetBytes(this.EncryptKey);//得到加密密钥
byte[] toEncrypt=this.EncodingMode.GetBytes(str);//得到要加密的内容
byte[] encrypted;
ICryptoTransform encryptor=des.CreateEncryptor(keyb,ivb);
MemoryStream msEncrypt=new MemoryStream();
CryptoStream csEncrypt=new CryptoStream(msEncrypt,encryptor,CryptoStreamMode.Write);
csEncrypt.Write(toEncrypt,0,toEncrypt.Length);
csEncrypt.FlushFinalBlock();
encrypted=msEncrypt.ToArray();
csEncrypt.Close();
msEncrypt.Close();
return this.EncodingMode.GetString(encrypted);
}
/// <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");
}
}
/// <summary>
/// 文件加密函数的重载版本,如果不指定输出路径,
/// 那么原来的文件将被加密后的文件覆盖
/// </summary>
/// <param name="filePath"></param>
public void EncryptFile(string filePath)
{
this.EncryptFile(filePath,filePath);
}
/// <summary>
/// 解密给定的字符串
/// </summary>
/// <param name="str">要解密的字符</param>
/// <returns></returns>
public string DecryptString(string str)
{
byte[] ivb=Encoding.ASCII.GetBytes(this.iv);
byte[] keyb=Encoding.ASCII.GetBytes(this.EncryptKey);
byte[] toDecrypt=this.EncodingMode.GetBytes(str);
byte[] deCrypted=new byte[toDecrypt.Length];
ICryptoTransform deCryptor=des.CreateDecryptor(keyb,ivb);
MemoryStream msDecrypt=new MemoryStream(toDecrypt);
CryptoStream csDecrypt=new CryptoStream(msDecrypt,deCryptor,CryptoStreamMode.Read);
try
{
csDecrypt.Read(deCrypted,0,deCrypted.Length);
}
catch(Exception err)
{
throw new ApplicationException(err.Message);
}
finally
{
try
{
msDecrypt.Close();
csDecrypt.Close();
}
catch{;}
}
return this.EncodingMode.GetString(deCrypted);
}
/// <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");
}
}
/// <summary>
/// 解密文件的重载版本,如果没有给出解密后文件的输出路径,
/// 则解密后的文件将覆盖先前的文件
/// </summary>
/// <param name="filePath"></param>
public void DecryptFile(string filePath)
{
this.DecryptFile(filePath,filePath);
}
#endregion
}
/// <summary>
/// MD5加密类,注意经MD5加密过的信息是不能转换回原始数据的
/// ,请不要在用户敏感的信息中使用此加密技术,比如用户的密码,
/// 请尽量使用对称加密
/// </summary>
public class MD5Encrypt
{
private MD5 md5;
public MD5Encrypt()
{
md5=new MD5CryptoServiceProvider();
}
/// <summary>
/// 从字符串中获取散列值
/// </summary>
/// <param name="str">要计算散列值的字符串</param>
/// <returns></returns>
public string GetMD5FromString(string str)
{
byte[] toCompute=Encoding.Unicode.GetBytes(str);
byte[] hashed=md5.ComputeHash(toCompute,0,toCompute.Length);
return Encoding.ASCII.GetString(hashed);
}
/// <summary>
/// 根据文件来计算散列值
/// </summary>
/// <param name="filePath">要计算散列值的文件路径</param>
/// <returns></returns>
public string GetMD5FromFile(string filePath)
{
bool isExist=File.Exists(filePath);
if(isExist)//如果文件存在
{
FileStream stream=new FileStream(filePath,FileMode.Open,FileAccess.Read);
StreamReader reader=new StreamReader(stream,Encoding.Unicode);
string str=reader.ReadToEnd();
byte[] toHash=Encoding.Unicode.GetBytes(str);
byte[] hashed=md5.ComputeHash(toHash,0,toHash.Length);
stream.Close();
return Encoding.ASCII.GetString(hashed);
}
else//文件不存在
{
throw new FileNotFoundException("指定的文件没有找到");
}
}
}
/// <summary>
/// 用于数字签名的hash类
/// </summary>
public class MACTripleDESEncrypt
{
private MACTripleDES mact;
private string __key="ksn168ch";
private byte[] __data=null;
public MACTripleDESEncrypt()
{
mact=new MACTripleDES();
}
/// <summary>
/// 获取或设置用于数字签名的密钥
/// </summary>
public string Key
{
get{return this.__key;}
set
{
int keyLength=value.Length;
int[] keyAllowLengths=new int[]{8,16,24};
bool isRight=false;
foreach(int i in keyAllowLengths)
{
if(keyLength==keyAllowLengths[i])
{
isRight=true;
break;
}
}
if(!isRight)
throw new ApplicationException("用于数字签名的密钥长度必须是8,16,24值之一");
else
this.__key=value;
}
}
/// <summary>
/// 获取或设置用于数字签名的用户数据
/// </summary>
public byte[] Data
{
get{return this.__data;}
set{this.__data=value;}
}
/// <summary>
/// 得到签名后的hash值
/// </summary>
/// <returns></returns>
public string GetHashValue()
{
if(this.Data==null)
throw new NotSetSpecialPropertyException("没有设置要进行数字签名的用户"+
"数据(property:Data)");
byte[] key=Encoding.ASCII.GetBytes(this.Key);
this.mact.Key=key;
byte[] hash_b=this.mact.ComputeHash(this.mact.ComputeHash(this.Data));
return Encoding.ASCII.GetString(hash_b);
}
}
}
