一个java的des加密解密代码如下：
//package com.visionsky.util;import java.security.*;//import java.util.regex.Pattern;//import java.util.Hashtable;import javax.crypto.*;import javax.crypto.spec.*;import sun.misc.*;/** * des加密解密 */public class DESPlus { private static String strDefaultKey = "PLFP"; //默认密钥 private static final byte[] iv = {0x12, 0x34, 0x56, 0x78, (byte) 0x90, (byte) 0xab, (byte) 0xcd, (byte) 0xef};//des 向量 private static BASE64Encoder enc = new BASE64Encoder();//将byte[]转换成String private static BASE64Decoder dec = new BASE64Decoder(); //将String转换成byte[] /** * 加密字节数组 * * @param arrB * 需加密的字节数组 * @param key * 密钥 * @return 加密后的字节数组 * @throws Exception */ public static byte[] encrypt(byte[] arrB, String key) throws Exception { DESKeySpec desKeySpec = new DESKeySpec(key.getBytes()); SecretKeyFactory keyFactory = SecretKeyFactory.getInstance("DES"); SecretKey secretKey = keyFactory.generateSecret(desKeySpec); IvParameterSpec ivp = new IvParameterSpec(DESPlus.iv); Cipher encryptCipher = Cipher.getInstance("DES/CBC/PKCS5Padding"); encryptCipher.init(Cipher.ENCRYPT_MODE, secretKey, ivp); return encryptCipher.doFinal(arrB); } /** * 加密字符串 * * @param xml * 需加密的字符串 * @param key * 密钥 * @return 加密后的字符串 * @throws Exception */ public static String encrypt(String xml, String key) throws Exception { //return DESPlus.enc.encode(encrypt(xml.getBytes(), key)); return new String(encrypt(xml.getBytes(), key)); } /** * 使用默认公钥加密字符串 * @param xml 需加密的字符串 * @return 加密后的字符串 * @throws Exception */ public static String encrypt(String xml) throws Exception { return encrypt(xml, strDefaultKey); } /** * 解密字节数组 * * @param arrB * 需解密的字节数组 * @param key * 密钥 * @return 解密后的字节数组 * @throws Exception */ public static byte[] decrypt(byte[] arrB, String key) throws Exception { DESKeySpec desKeySpec = new DESKeySpec(key.getBytes()); SecretKeyFactory keyFactory = SecretKeyFactory.getInstance("DES"); SecretKey secretKey = keyFactory.generateSecret(desKeySpec); IvParameterSpec ivp = new IvParameterSpec(DESPlus.iv); Cipher decryptCipher = Cipher.getInstance("DES/CBC/PKCS5Padding"); decryptCipher.init(Cipher.DECRYPT_MODE, secretKey, ivp); return decryptCipher.doFinal(arrB); } /** * 解密字符串 * * @param xml * 需解密的字符串 * @param key * 密钥 * @return 解密后的字符串 * @throws Exception */ public static String decrypt(String xml, String key) throws Exception { return new String(decrypt(DESPlus.dec.decodeBuffer(xml), key)); } /** * 使用默认公钥解密字符串 * @param xml 需解密的字符串 * @return 解密后的字符串 * @throws Exception */ public static String decrypt(String xml) throws Exception { return decrypt(xml, strDefaultKey); } /** * 从指定字符串生成密钥，密钥所需的字节数组长度为8位 不足8位时后面补0，超出8位只取前8位 * * @param arrBTmp * 构成该字符串的字节数组 * @return 生成的密钥 * @throws java.lang.Exception */ private Key getKey(byte[] arrBTmp) throws Exception { // 创建一个空的8位字节数组（默认值为0） byte[] arrB = new byte[8]; // 将原始字节数组转换为8位 for (int i = 0; i < arrBTmp.length && i < arrB.length; i++) { arrB[i] = arrBTmp[i]; } // 生成密钥 Key key = new javax.crypto.spec.SecretKeySpec(arrB, "DES"); return key; } /** * 获取默认密钥 * @return */ public static String getDesKey() { return DESPlus.strDefaultKey; } public static void main(String[] args) { try { //测试密匙 String key = "BOC_PLFP"; //004交易案例 String xml = " 004 17850 COM01 1109141222222660161 0000000123 客户信息不完整，请补充资料。 "; System.out.println("密钥：" + key); System.out.println("加密前的字符串：" + xml); System.out.println("加密前的字符串长度：" + xml.getBytes().length); //加密 xml = DESPlus.encrypt(xml, key); System.out.println("加密后的字符串：" + xml); System.out.println("加密后的字符串长度：" + xml.getBytes().length); //解密 xml = DESPlus.decrypt(xml, key); System.out.println("解密后的字符串：" + xml); System.out.println("解密后的字符串长度：" + xml.getBytes().length); } catch (Exception e) { e.printStackTrace(); } }}
上面运行结果为：
密钥：BOC_PLFP 加密前的字符串：<?xml version="1.0" encoding="UTF-8"?><ROOT><HEADER><TRANNO>004</TRANNO><BNKNO>17850</BNKNO><COMNO>COM01</COMNO><SN>1109141222222660161</SN></HEADER><BODY><TRANLOG><APPNO>0000000123</APPNO><NOTATION>客户信息不完整，请补充资料。</NOTATION></TRANLOG></BODY></ROOT> 加密前的字符串长度：262 加密后的字符串：bE5N44gjyfO3SdUs6/OhVg4I4l725S2vWcKBRxYOAd/eAnyuADKXeNNgVXJMj3aJJzndntv364rh YW2bF33lmEABMU43HfS8DcXX7+QrcIjp3mrk7uJdiNHu4T4oHMeqetFZqU5oh2XY1sbBPPdGEgMf /OguRVaTblzl/ylkFc6C9BNNSD0IwL0Ks7Mi73+V76P+aFdPgXQc7u4Vkq8Cd6+HgHErbHbJI729 JPJKM5L2YAAW4Q06oi4yMoEASDjYf7Aa1X/FWqclsZImSDB0okGOiuj857l94BM1zYl2RtWdXa9o 0beiL4CbEvKSC3U3PydAI0+mZbtE0sVkyP0sXTke7ifrwiMG 加密后的字符串长度：360 解密后的字符串：<?xml version="1.0" encoding="UTF-8"?><ROOT><HEADER><TRANNO>004</TRANNO><BNKNO>17850</BNKNO><COMNO>COM01</COMNO><SN>1109141222222660161</SN></HEADER><BODY><TRANLOG><APPNO>0000000123</APPNO><NOTATION>客户信息不完整，请补充资料。</NOTATION></TRANLOG></BODY></ROOT> 解密后的字符串长度：262 参考了http://www.lijingquan.net/des-c-php-java.html一文，修改里面的des向量iv，字符编码UTF8为Default等，最终 改写为C#代码如下：using System;using System.Collections.Generic;using System.Linq;using System.Text;using System.Security.Cryptography;public class DES{ private const string defaultKey = "BOC_PLFP"; //默认密钥 private static byte[] iv = { 0x12, 0x34, 0x56, 0x78, (byte)0x90, (byte)0xab, (byte)0xcd, (byte)0xef };//des 向量 /// /// des加密 /// /// 要加密的字符串。 /// 密钥，且必须为8位。默认公钥加密字符串defaultKey /// 以Base64格式返回的加密字符串。 public static string Encrypt(string pToEncrypt, string sKey = defaultKey) { using (DESCryptoServiceProvider des = new DESCryptoServiceProvider()) { byte[] inputByteArray = Encoding.Default.GetBytes(pToEncrypt); des.Key = ASCIIEncoding.ASCII.GetBytes(sKey); des.IV = iv; //ASCIIEncoding.ASCII.GetBytes(sKey); System.IO.MemoryStream ms = new System.IO.MemoryStream(); using (CryptoStream cs = new CryptoStream(ms, des.CreateEncryptor(), CryptoStreamMode.Write)) { cs.Write(inputByteArray, 0, inputByteArray.Length); cs.FlushFinalBlock(); cs.Close(); } string str = Convert.ToBase64String(ms.ToArray()); ms.Close(); return str; } } /// /// des解密 /// /// 要解密的以Base64 /// 密钥，且必须为8位。默认公钥解密字符串defaultKey /// 已解密的字符串。 public static string Decrypt(string pToDecrypt, string sKey = defaultKey) { byte[] inputByteArray = Convert.FromBase64String(pToDecrypt); using (DESCryptoServiceProvider des = new DESCryptoServiceProvider()) { des.Key = ASCIIEncoding.ASCII.GetBytes(sKey); des.IV = iv; // ASCIIEncoding.ASCII.GetBytes(sKey); System.IO.MemoryStream ms = new System.IO.MemoryStream(); using (CryptoStream cs = new CryptoStream(ms, des.CreateDecryptor(), CryptoStreamMode.Write)) { cs.Write(inputByteArray, 0, inputByteArray.Length); cs.FlushFinalBlock(); cs.Close(); } string str = Encoding.Default.GetString(ms.ToArray()); ms.Close(); return str; } }} 经测试，加密和解密的结果和java的一样。