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| 安全问题：C#做的一个加密/解密的类 |
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来源：Dotnet频道 |
作者：采集 |
时间：2008-3-31 |
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代码如下：
using System;
using System.Security.Cryptography ;
using System.Text;
using System.IO;
namespace SEDO
{
/// <summary>
/// SEDO 的摘要说明。
/// SEDO 实现的是用一个封装了4种对称加密方法(Des,Rc2,Rijndael,TripleDes)的组件
///
/// 注意事项：
/// 1:TripleDes和Rijndael加密/解密对象使用16或者24位byte的Key
/// 2:Rijndael只能使用16位的初始化向量IV
/// 3:Des和Rc2均使用8位Byte的Key和IV
/// 4:对需要加密/解密的数据流采用何种方法进行编码/解码，由调用组件的用户自己决定
/// 5:密钥和初始化向量IV由使用者自己定义
/// 程序员： 王海波 2003-05-19 hwnanghb@21cn.com
/// </summary>
//定义加密类型的枚举
public enum EncryptionAlgorithm {Des = 1, Rc2, Rijndael, TripleDes};
//定义加密类
internal class EncryptTransformer
{
private EncryptionAlgorithm algorithmID;
private byte[] initVec;
private byte[] encKey;
internal EncryptTransformer(EncryptionAlgorithm algId)
{
//Save the algorithm being used.
algorithmID = algId;
}
internal ICryptoTransform GetCryptoServiceProvider(byte[] bytesKey)
{
//当数据密钥Key或者初始化向量IV为空的时候，将使用加密对象自动产生的密钥Key或者初始化向量IV
switch (algorithmID)
{
case EncryptionAlgorithm.Des:
{
DES des = new DESCryptoServiceProvider();
des.Mode = CipherMode.CBC;
// See if a key was provided
if (null == bytesKey)
{
encKey = des.Key;
}
else
{
des.Key = bytesKey;
encKey = des.Key;
}
// See if the client provided an initialization vector
if (null == initVec)
{ // Have the algorithm create one
initVec = des.IV;
}
else
{ //No, give it to the algorithm
des.IV = initVec;
}
return des.CreateEncryptor();
}
case EncryptionAlgorithm.TripleDes:
{
TripleDES des3 = new TripleDESCryptoServiceProvider();
des3.Mode = CipherMode.CBC;
// See if a key was provided
if (null == bytesKey)
{
encKey = des3.Key;
}
else
{
des3.Key = bytesKey;
encKey = des3.Key;
}
// See if the client provided an IV
if (null == initVec)
{ //Yes, have the alg create one
initVec = des3.IV;
}
else
{ //No, give it to the alg.
des3.IV = initVec;
}
return des3.CreateEncryptor();
}
case EncryptionAlgorithm.Rc2:
{
RC2 rc2 = new RC2CryptoServiceProvider();
rc2.Mode = CipherMode.CBC;
// Test to see if a key was provided
if (null == bytesKey)
{
encKey = rc2.Key;
}
else
{
rc2.Key = bytesKey;
encKey = rc2.Key;
}
// See if the client provided an IV
if (null == initVec)
{ //Yes, have the alg create one
initVec = rc2.IV;
}
else
{ //No, give it to the alg.
rc2.IV = initVec;
}
return rc2.CreateEncryptor();
}
case EncryptionAlgorithm.Rijndael:
{
Rijndael rijndael = new RijndaelManaged();
rijndael.Mode = CipherMode.CBC;
// Test to see if a key was provided
if(null == bytesKey)
{
encKey = rijndael.Key;
}
else
{
rijndael.Key = bytesKey;
encKey = rijndael.Key;
}
// See if the client provided an IV
if(null == initVec)
{ //Yes, have the alg create one
initVec = rijndael.IV;
}
else
{ //No, give it to the alg.
rijndael.IV = initVec;
}
return rijndael.CreateEncryptor();
}
default:
{
throw new CryptographicException("Algorithm ID '" +
algorithmID +
"' not supported.");
}
}
}
//加密的偏移向量
internal byte[] IV
{
get{return initVec;}
set{initVec = value;}
}
//加密的密钥
internal byte[] Key
{
get{return encKey;}
set{encKey = value;}
}
}
//定义解密类
internal class DecryptTransformer
{
private EncryptionAlgorithm algorithmID;
private byte[] initVec;
private byte[] encKey;
internal DecryptTransformer(EncryptionAlgorithm deCryptId)
{
algorithmID = deCryptId;
}
//加密的偏移向量
internal byte[] IV
{
get{return initVec;}
set{initVec = value;}
}
//加密的密钥
internal byte[] Key
{
get{return encKey;}
set{encKey = value;}
}
internal ICryptoTransform GetCryptoServiceProvider(byte[] bytesKey)
{
//当数据密钥Key或者初始化向量IV为空的时候，将使用加密对象自动产生的密钥Key或者初始化向量IV
switch (algorithmID)
{
case EncryptionAlgorithm.Des:
{
DES des = new DESCryptoServiceProvider();
des.Mode = CipherMode.CBC;
des.Key = bytesKey;
des.IV = initVec;
return des.CreateDecryptor();
}
case EncryptionAlgorithm.TripleDes:
{
TripleDES des3 = new TripleDESCryptoServiceProvider();
des3.Mode = CipherMode.CBC;
return des3.CreateDecryptor(bytesKey, initVec);
}
case EncryptionAlgorithm.Rc2:
{
RC2 rc2 = new RC2CryptoServiceProvider();
rc2.Mode = CipherMode.CBC;
return rc2.CreateDecryptor(bytesKey, initVec);
}
case EncryptionAlgorithm.Rijndael:
{
Rijndael rijndael = new RijndaelManaged();
rijndael.Mode = CipherMode.CBC;
return rijndael.CreateDecryptor(bytesKey, initVec);
}
default:
{
throw new CryptographicException("Algorithm ID '" +
algorithmID +
"' not supported.");
}
}
} //end GetCryptoServiceProvider
}
//定义加密者类
public class Encryptor
{
private EncryptTransformer transformer;
private byte[] initVec;
private byte[] encKey;
public Encryptor(EncryptionAlgorithm algId)
{
transformer = new EncryptTransformer(algId);
}
public byte[] Encrypt(byte[] bytesData, byte[] bytesKey,byte[] bytesIV)
{
//设置流对象用来保存加密数据字节流.
MemoryStream memStreamEncryptedData = new MemoryStream();
transformer.IV=bytesIV;
transformer.Key=bytesKey;
ICryptoTransform transform = transformer.GetCryptoServiceProvider(bytesKey);
CryptoStream encStream = new CryptoStream(memStreamEncryptedData,transform,CryptoStreamMode.Write);
try
{
//将加密数据写进流对象
encStream.Write(bytesData, 0, bytesData.Length);
}
catch(Exception ex)
{
throw new Exception("在数据加密的时候出现错误！错误提示： \n" + ex.Message);
}
//设置加密的Key和初始向量IV属性
encKey = transformer.Key;
initVec = transformer.IV;
encStream.FlushFinalBlock();
encStream.Close();
//Send the data back.
return memStreamEncryptedData.ToArray();
}
public byte[] IV
{
get{return initVec;}
set{initVec = value;}
}
public byte[] Key
{
get{return encKey;}
set{encKey = value;}
}
}
//定义解密者类
public class Decryptor
{
private DecryptTransformer transformer;
private byte[] initVec;
private byte[] encKey;
public Decryptor(EncryptionAlgorithm algId)
{
transformer = |
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