.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); } }}?