C#加密解密方法.doc

.NET 与 Java DES 加密\解密 互通 方式
2009-1-9 17:44:54

由于.net DES 对称算法的运算模式。默认值为CipherMode.CBC（密码块链模式）
而java默认运算模式是ECB（电子密码本模式 ）,具体模式介绍请参考MSDN

所以 只需要指定DES 对称算法的运算模式为ECB 就可以实现与Java DES加密、解密的互通

附上.net DES加密、解密代码

using System;
using System.Text;
using System.Security.Cryptography;

/// <summary>
/// DESEncrypt 的摘要说明。
/// </summary>
public class DESEncrypt
{
public DESEncrypt()
{
}

#region ========加密========

/// <summary>
/// 加密
/// </summary>
/// <param name="Text"></param>
/// <returns></returns>
public static string Encrypt(string Text)
{
return Encrypt(Text,"xxxxxxx");
}
/// <summary>
/// 加密数据
/// </summary>
/// <param name="Text"></param>
/// <param name="sKey"></param>
/// <returns></returns>
public static string Encrypt(string Text,string sKey)
{
DESCryptoServiceProvider des = new DESCryptoServiceProvider();
des.Mode = System.Security.Cryptography.CipherMode.ECB;
byte[] inputByteArray;
inputByteArray=Encoding.Default.GetBytes(Text);
des.Key = ASCIIEncoding.ASCII.GetBytes(sKey);
des.IV =ASCIIEncoding.ASCII.GetBytes(sKey);
System.IO.MemoryStream ms=new System.IO.MemoryStream();
CryptoStream cs=new CryptoStream(ms,des.CreateEncryptor(),CryptoStreamMode.Write);
cs.Write(inputByteArray,0,inputByteArray.Length);
cs.FlushFinalBlock();
StringBuilder ret=new StringBuilder();
foreach( byte b in ms.ToArray())
{
ret.AppendFormat("{0:X2}",b);
}
return ret.ToString();
}

#endregion

#region ========解密========

/// <summary>
/// 解密
/// </summary>
/// <param name="Text"></param>
/// <returns></returns>
public static string Decrypt(string Text)
{
return Decrypt(Text,"xxxxxxx");
}
/// <summary>
/// 解密数据
/// </summary>
/// <param name="Text"></param>
/// <param name="sKey"></param>
/// <returns></returns>
public static string Decrypt(string Text,string sKey)
{
DESCryptoServiceProvider des = new DESCryptoServiceProvider();
des.Mode = System.Security.Cryptography.CipherMode.ECB;
int len;
len=Text.Length/2;
byte[] inputByteArray = new byte[len];
int x,i;
for(x=0;x<len;x++)
{
i = Convert.ToInt32(Text.Substring(x * 2, 2), 16);
inputByteArray[x]=(byte)i;
}
des.Key = ASCIIEncoding.ASCII.GetBytes(sKey);
des.IV = ASCIIEncoding.ASCII.GetBytes(sKey);
System.IO.MemoryStream ms=new System.IO.MemoryStream();
CryptoStream cs=new CryptoStream(ms,des.CreateDecryptor(),CryptoStreamMode.Write);
cs.Write(inputByteArray,0,inputByteArray.Length);
cs.FlushFinalBlock();
return Encoding.Default.GetString(ms.ToArray());
}

#endregion
}[原文地址：

今天碰上一件令我头大的事情。我们的系统要和一个外部系统进行通讯，传输方式是采用 DES 算法对消息进行加密，再用 BASE64 编码。不过对方系统是用 C# 写的。平台不一样，于是我和对面的老兄先测试一下加密解密。这一测试问题就来了。两边采用同样的密钥，对同一个字符串加密出来的结果不一样。怎么办呢？我先把他那边的代码要过来了，他是这样写的(C#)：

public static string Encrypt(string message, string key)
{
DES des = new DESCryptoServiceProvider();
des.Key = Encoding.UTF8.GetBytes(key);
des.IV = Encoding.UTF8.GetBytes(key);

byte[] bytes = Encoding.UTF8.GetBytes(message);
byte[] resultBytes = des.CreateEncryptor().TransformFinalBlock(bytes, 0, bytes.Length);

return Convert.ToBase64String(resultBytes);
}

而我这边呢，是用 Java 这样写的（仅仅加密到字节串，BASE64 编码是在另一个类里）：

public static byte[] desEncrypt(String message, String key) throws Exception {
Cipher cipher = Cipher.getInstance("DES");

DESKeySpec desKeySpec = new DESKeySpec(key.getBytes("UTF-8"));
SecretKeyFactory keyFactory = SecretKeyFactory.getInstance("DES");
SecretKey secretKey = keyFactory.generateSecret(desKeySpec);
cipher.init(Cipher.ENCRYPT_MODE, secretKey);

return cipher.doFinal(message.getBytes("UTF-8"));
}

两边一对比我就奇怪了，他那边怎么有个 IV (initialization vector)？我打开JDK文档一看Cipher类，竟然也有一个getIV()方法。看来这 IV 大有来头。于是在JDK文档里面到处找IV，找到了一个叫“IvParameterSpec“的类，莫非就是它？它实现的是 AlgorithmParameterSpec 接口，而Cipher.init()中就有一个 AlgorithmParameterSpec 类型的参数。那么看来就是它了。于是参考了IvParameterSpec的构造函数后，我这样把它加进去：

public static byte[] desEncrypt(String message, String key) throws Exception {
Cipher cipher = Cipher.getInstance("DES");

DESKeySpec desKeySpec = new DESKeySpec(key.getBytes("UTF-8"));

SecretKeyFactory keyFactory = SecretKeyFactory.getInstance("DES");
SecretKey secretKey = keyFactory.generateSecret(desKeySpec);
IvParameterSpec iv = new IvParameterSpec(key.getBytes("UTF-8"));
cipher.init(Cipher.ENCRYPT_MODE, secretKey, iv);

return cipher.doFinal(message.getBytes("UTF-8"));
}

这下行了吧，结果一运行报异常：

java.security.InvalidAlgorithmParameterException: ECB mode cannot use IV

这又是什么？ “ECB”？ 还是找吧，在JDK文档中找到了这么几句鬼东西：

the SunJCE provider uses ECB as the default mode, and PKCS5 Padding as the default padding scheme for DES, DES-EDE and Blowfish ciphers. This means that in the case of the SunJCE provider,
Cipher c1 = Cipher.getInstance("DES/ECB/PKCS5Padding");
and
Cipher c1 = Cipher.getInstance("DES");
are equivalent statements.

哦，问题就出在方法里的第一行。那么不准用 ECB，该用什么呢？在该文往下找，找到了这么几项：

The following names can be specified as the mode component in a transformation when requesting an instance of Cipher:
NONE: No mode.
CBC: Cipher Block Chaining Mode, as defined in FIPS PUB 81.
CFB: Cipher Feedback Mode, as defined in FIPS PUB 81.
ECB: Electronic Codebook Mode, as defined in: The National Institute of Standards and Technology (NIST) Federal Information Processing Standard (FIPS) PUB 81, "DES Modes of Operation," U.S. Department of Commerce, Dec 1980.
OFB: Output Feedback Mode, as defined in FIPS PUB 81.
PCBC: Propagating Cipher Block Chaining, as defined by Kerberos V4.

我这样都换着试一下就行了。哎，运气不错，拿着第一个 CBC 试一下就成功了，加密后的字符串也“正确”了。
我那个方法就变成这样：

public static byte[] desEncrypt(String message, String key) throws Exception {
Cipher cipher = Cipher.getInstance("DES/CBC/PKCS5Padding");

DESKeySpec desKeySpec = new DESKeySpec(key.getBytes("UTF-8"));

SecretKeyFactory keyFactory = SecretKeyFactory.getInstance("DES");
SecretKey secretKey = keyFactory.generateSecret(desKeySpec);
IvParameterSpec iv = new IvParameterSpec(key.getBytes("UTF-8"));
cipher.init(Cipher.ENCRYPT_MODE, secretKey, iv);

return cipher.doFinal(message.getBytes("UTF-8"));
}

这样，解决了这个 ECB 之后，Java 和 .net 平台的两个应用终于能够相互加密和解密数据了。

[原文地址：
2010-07-08 11:32
这里贴出来的是可通用的C#与java的DES加密类，希望对大家管用直接复制即可用

C#DES加密解密类

///<summary><![CDATA[加密解密帮助类]]></summary>
public class Help_Encrypt

{

///<summary><![CDATA[字符串DES加密函数]]></summary>
///<param name="str"><![CDATA[被加密字符串 ]]></param>
///<param name="key"><![CDATA[密钥 ]]></param>
///<returns><![CDATA[加密后字符串]]></returns>
public static string Encode(string str, string key)
{

try
{
DESCryptoServiceProvider provider = new DESCryptoServiceProvider();
provider.Key = Encoding.ASCII.GetBytes(key.Substring(0, 8));
provider.IV = Encoding.ASCII.GetBytes(key.Substring(0, 8));
byte[] bytes = Encoding.GetEncoding("GB2312").GetBytes(str);
MemoryStream stream = new MemoryStream();
CryptoStream stream2 = new CryptoStream(stream, provider.CreateEncryptor(), CryptoStreamMode.Write);
stream2.Write(bytes, 0, bytes.Length);
stream2.FlushFinalBlock();
StringBuilder builder = new StringBuilder();
foreach (byte num in stream.ToArray())
{
builder.AppendFormat("{0:X2}", num);
}
stream.Close();
return builder.ToString();

}
catch (Exception) { return "xxxx"; }
}

///<summary><![CDATA[字符串DES解密函数]]></summary>
///<param name="str"><![CDATA[被解密字符串 ]]></param>
///<param name="key"><![CDATA[密钥 ]]></param>
///<returns><![CDATA[解密后字符串]]></returns>
public static string Decode(string str, string key)
{
try
{

DESCryptoServiceProvider provider = new DESCryptoServiceProvider();
provider.Key = Encoding.ASCII.GetBytes(key.Substring(0, 8));
provider.IV = Encoding.ASCII.GetBytes(key.Substring(0, 8));
byte[] buffer = new byte[str.Length / 2];
for (int i = 0; i < (str.Length / 2); i++)
{
int num2 = Convert.ToInt32(str.Substring(i * 2, 2), 0x10);
buffer[i] = (byte)num2;
}
MemoryStream stream = new MemoryStream();
CryptoStream stream2 = new CryptoStream(stream, provider.CreateDecryptor(), CryptoStreamMode.Write);
stream2.Write(buffer, 0, buffer.Length);
stream2.FlushFinalBlock();
stream.Close();
return Encoding.GetEncoding("GB2312").GetString(stream.ToArray());
}
catch (Exception) { return ""; }
}

}

JAVADES加密解密类

package com.bgxt.messages;

import java.io.UnsupportedEncodingException;
import java.security.*;

import javax.crypto.Cipher;

import javax.crypto.SecretKey;

import javax.crypto.SecretKeyFactory;

import javax.crypto.spec.DESKeySpec;
import javax.crypto.spec.IvParameterSpec;

/**

* 字符串工具集合

* @author Liudong

*/

public class StringUtils {

private static final String PASSWORD_CRYPT_KEY = XmlUtil.getConfig().getPasswdKey().substring(0,8);
//private final static String DES = "DES";
//private static final byte[] desKey;

//解密数据
public static String decrypt(String message,String key) throws Exception {

byte[] bytesrc =convertHexString(message);
Cipher cipher = Cipher.getInstance("DES/CBC/PKCS5Padding");
DESKeySpec desKeySpec = new DESKeySpec(key.getBytes("UTF-8"));
SecretKeyFactory keyFactory = SecretKeyFactory.getInstance("DES");
SecretKey secretKey = keyFactory.generateSecret(desKeySpec);
IvParameterSpec iv = new IvParameterSpec(key.getBytes("UTF-8"));
cipher.init(Cipher.DECRYPT_MODE, secretKey, iv);
byte[] retByte = cipher.doFinal(bytesrc);
return new String(retByte);
}

public static byte[] encrypt(String message, String key)
throws Exception {
Cipher cipher = Cipher.getInstance("DES/CBC/PKCS5Padding");

DESKeySpec desKeySpec = new DESKeySpec(key.getBytes("UTF-8"));

SecretKeyFactory keyFactory = SecretKeyFactory.getInstance("DES");
SecretKey secretKey = keyFactory.generateSecret(desKeySpec);
IvParameterSpec iv = new IvParameterSpec(key.getBytes("UTF-8"));
cipher.init(Cipher.ENCRYPT_MODE, secretKey, iv);

return cipher.doFinal(message.getBytes("UTF-8"));
}

public static String encrypt(String value){
String result="";
try{
value=.URLEncoder.encode(value, "utf-8");
result=toHexString(encrypt(value, PASSWORD_CRYPT_KEY)).toUpperCase();
}catch(Exception ex){
ex.printStackTrace();
return "";
}
return result;
}
public static byte[] convertHexString(String ss)
{
byte digest[] = new byte[ss.length() / 2];
for(int i = 0; i < digest.length; i++)
{
String byteString = ss.substring(2 * i, 2 * i + 2);
int byteValue = Integer.parseInt(byteString, 16);
digest[i] = (byte)byteValue;
}
return digest;
}

public static String toHexString(byte b[]) {
StringBuffer hexString = new StringBuffer();
for (int i = 0; i < b.length; i++) {
String plainText = Integer.toHexString(0xff & b[i]);
if (plainText.length() < 2)
plainText = "0" + plainText;
hexString.append(plainText);
}
return hexString.toString();
}
public static void main(String[] args) throws Exception {
String value="01";
System.out.println("加密数据:"+value);
System.out.println("密码为:"+XmlUtil.getConfig().getPasswdKey());
String a=encrypt( value);
System.out.println("加密后的数据为:"+a);
}
}C#加密解密方法

1、方法一 (不可逆加密)

public string EncryptPassword(string PasswordString,string PasswordFormat )
{
string encryptPassword = null;
if (PasswordFormat="SHA1"){
encryptPassword=FormsAuthortication.HashPasswordForStoringInConfigFile(PasswordString

,"SHA1");
}
elseif (PasswordFormat="MD5")
{ encryptPassword=FormsAuthortication.HashPasswordForStoringInConfigFile(PasswordString

,"MD5");
}
return encryptPassword ;
}

2、方法二 (可逆加密)

public interface IBindesh
{
string encode(string str);
string decode(string str);
}

public class EncryptionDecryption : IBindesh
{
public string encode(string str)
{
string htext = "";

for ( int i = 0; i < str.Length; i++)
{
htext = htext + (char) (str[i] + 10 - 1_*2);
}
return htext;
}

public string decode(string str)
{
string dtext = "";

for ( int i=0; i < str.Length; i++)
{
dtext = dtext + (char) (str[i] - 10 + 1*2);
}
return dtext;
}

3、方法三 (可逆加密)

const string KEY_64 = "VavicApp";//注意了，是8个字符，64位

const string IV_64 = "VavicApp";
public string Encode(string data)
{
byte[] byKey = System.Text.ASCIIEncoding.ASCII.GetBytes(KEY_64);
byte[] byIV = System.Text.ASCIIEncoding.ASCII.GetBytes(IV_64);

DESCryptoServiceProvider cryptoProvider = new DESCryptoServiceProvider();
int i = cryptoProvider.KeySize;
MemoryStream ms = new MemoryStream();
CryptoStream cst = new CryptoStream(ms, cryptoProvider.CreateEncryptor(byKey,

byIV), CryptoStreamMode.Write);

StreamWriter sw = new StreamWriter(cst);
sw.Write(data);
sw.Flush();
cst.FlushFinalBlock();
sw.Flush();
return Convert.ToBase64String(ms.GetBuffer(), 0, (int)ms.Length);

}

public string Decode(string data)
{
byte[] byKey = System.Text.