标题
[加密/des/3des/] java 的 des 算法居然与 c 的不同
clq
浏览(0) +
2009-07-20 16:13:11 发表
编辑
关键字:
//用 "DES/ECB/NOPADDING" 后加密和解密的字符串都利用 8 倍数长度的字符串,一般是补空格
据说 ECB/NOPADDING 是为了和其他语言兼容,默认情况下是 sun jdk 自己的字节补充算法,与其他语言及 jdk (比如 ibm 的)不兼容.
--------------------------------------------------
public DESPlus(String strKey) throws Exception
{
//用 "DES/ECB/NOPADDING" 后加密和解密的字符串都利用 8 倍数长度的字符串,一般是补空格
//Cipher cipher = Cipher.getInstance("DES/ECB/NOPADDING"); // TripleDES/ECB/NoPadding
//你看下你用的吃cbc还是ecb，一般都用ecb，注意NOPADDING
Security.addProvider(new com.sun.crypto.provider.SunJCE());
//Key key = getKey(strKey.getBytes());
SecretKeySpec key = new SecretKeySpec(strKey.getBytes(), "DES");
//encryptCipher = Cipher.getInstance("DES");
encryptCipher = Cipher.getInstance("DES/ECB/NOPADDING");
encryptCipher.init(Cipher.ENCRYPT_MODE, key);
//decryptCipher = Cipher.getInstance("DES");
decryptCipher = Cipher.getInstance("DES/ECB/NOPADDING");
decryptCipher.init(Cipher.DECRYPT_MODE, key);
}
clq
附件[暂不开放下载]
上传一个代码. 用网上现有代码小改而成.
DESPlus.java
clq
package hpublic;
//des 加解密
import java.security.*;
import javax.crypto.*;
import javax.crypto.spec.SecretKeySpec;
import hpublic.*;
public class DESPlus {
private static String strDefaultKey = "national";
private Cipher encryptCipher = null;
private Cipher decryptCipher = null;
/**
* 将byte数组转换为表示16进制值的字符串， 如：byte[]{8,18}转换为：0813， 和public static byte[]
* hexStr2ByteArr(String strIn) 互为可逆的转换过程
*
* @param arrB
* 需要转换的byte数组
* @return 转换后的字符串
* @throws Exception
* 本方法不处理任何异常，所有异常全部抛出
*/
public static String byteArr2HexStr(byte[] arrB) throws Exception {
int iLen = arrB.length;
// 每个byte用两个字符才能表示，所以字符串的长度是数组长度的两倍
StringBuffer sb = new StringBuffer(iLen * 2);
for (int i = 0; i < iLen; i++) {
int intTmp = arrB[i];
// 把负数转换为正数
while (intTmp < 0) {
intTmp = intTmp + 256;
}
// 小于0F的数需要在前面补0
if (intTmp < 16) {
sb.append("0");
}
sb.append(Integer.toString(intTmp, 16));
}
return sb.toString();
}
/**
* 将表示16进制值的字符串转换为byte数组， 和public static String byteArr2HexStr(byte[] arrB)
* 互为可逆的转换过程
*
* @param strIn
* 需要转换的字符串
* @return 转换后的byte数组
* @throws Exception
* 本方法不处理任何异常，所有异常全部抛出
* @author LiGuoQing
*/
public static byte[] hexStr2ByteArr(String strIn) throws Exception {
byte[] arrB = strIn.getBytes();
int iLen = arrB.length;
// 两个字符表示一个字节，所以字节数组长度是字符串长度除以2
byte[] arrOut = new byte[iLen / 2];
for (int i = 0; i < iLen; i = i + 2) {
String strTmp = new String(arrB, i, 2);
arrOut[i / 2] = (byte) Integer.parseInt(strTmp, 16);
}
return arrOut;
}
/**
* 默认构造方法，使用默认密钥
*
* @throws Exception
*/
public DESPlus() throws Exception {
this(strDefaultKey);
}
/**
* 指定密钥构造方法
*
* @param strKey
* 指定的密钥
* @throws Exception
*/
public DESPlus(String strKey) throws Exception
{
//用 "DES/ECB/NOPADDING" 后加密和解密的字符串都利用 8 倍数长度的字符串,一般是补空格
//Cipher cipher = Cipher.getInstance("DES/ECB/NOPADDING"); // TripleDES/ECB/NoPadding
//你看下你用的吃cbc还是ecb，一般都用ecb，注意NOPADDING
Security.addProvider(new com.sun.crypto.provider.SunJCE());
//Key key = getKey(strKey.getBytes());
SecretKeySpec key = new SecretKeySpec(strKey.getBytes(), "DES");
//encryptCipher = Cipher.getInstance("DES");
encryptCipher = Cipher.getInstance("DES/ECB/NOPADDING");
encryptCipher.init(Cipher.ENCRYPT_MODE, key);
//decryptCipher = Cipher.getInstance("DES");
decryptCipher = Cipher.getInstance("DES/ECB/NOPADDING");
decryptCipher.init(Cipher.DECRYPT_MODE, key);
}
/**
* 加密字节数组
*
* @param arrB
* 需加密的字节数组
* @return 加密后的字节数组
* @throws Exception
*/
public byte[] encrypt(byte[] arrB) throws Exception {
return encryptCipher.doFinal(arrB);
}
/**
* 加密字符串
*
* @param strIn
* 需加密的字符串
* @return 加密后的字符串
* @throws Exception
*/
public String encrypt(String strIn) throws Exception
{
return byteArr2HexStr(encrypt(strIn.getBytes()));
/*
String r = "";
byte[] b = encrypt(strIn.getBytes());
for (int i = 0; i < b.length; i++)
{
String hex = Integer.toHexString(b[i] & 0xFF);
if (hex.length() == 1)
{
hex = '0' + hex;
}
r += hex.toLowerCase();
}
return r;
//*/
//return functions.HexString2Bytes(strIn)
}
/**
* 解密字节数组
*
* @param arrB
* 需解密的字节数组
* @return 解密后的字节数组
* @throws Exception
*/
public byte[] decrypt(byte[] arrB) throws Exception {
return decryptCipher.doFinal(arrB);
}
/**
* 解密字符串
*
* @param strIn
* 需解密的字符串
* @return 解密后的字符串
* @throws Exception
*/
public String decrypt(String strIn) throws Exception {
return new String(decrypt(hexStr2ByteArr(strIn)));
}
/**
* 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;
}
//--------------------------------------------------
public static byte[] des_encrypt(byte[] msg, byte[] pass) throws Exception {
byte[] input = msg;
byte[] keyBytes = pass;
SecretKeySpec key = new SecretKeySpec(keyBytes, "DES");
Cipher cipher = Cipher.getInstance("DES/ECB/NOPADDING"); // TripleDES/ECB/NoPadding
cipher.init(Cipher.ENCRYPT_MODE, key);
byte[] cipherText = new byte[cipher.getOutputSize(input.length)];
int ctLength = cipher.update(input, 0, input.length, cipherText, 0);
ctLength += cipher.doFinal(cipherText, ctLength);
return cipherText;
}
public static byte[] des_decrypt(byte[] s, byte[] k) throws Exception {
byte[] input = s;
byte[] keyBytes = k;
SecretKeySpec key = new SecretKeySpec(keyBytes, "DES");
Cipher cipher = Cipher.getInstance("DES/ECB/NOPADDING");
cipher.init(Cipher.DECRYPT_MODE, key);
byte[] cipherText = new byte[cipher.getOutputSize(input.length)];
int ctLength = cipher.update(input, 0, input.length, cipherText, 0);
ctLength += cipher.doFinal(cipherText, ctLength);
return cipherText;
}
//--------------------------------------------------
}
/*
测试程序 Test.java
public class Test {
public static void main(String[] args) {
// TODO Auto-generated method stub
try {
String test = "Hellow Word!";
//DESPlus des = new DESPlus();//默认密钥
DESPlus des = new DESPlus("leemenz");//自定义密钥
System.out.println("加密前的字符："+test);
System.out.println("加密后的字符："+des.encrypt(test));
System.out.println("解密后的字符："+des.decrypt(des.encrypt(test)));
} catch (Exception e) {
// TODO: handle exception
e.printStackTrace();
}
}
}
*/
clq
另外还有这样的说法.
"
java加密16位以下的字符串会和C的方法不一致 你试试16位以上的内容
"
NEWBT官方QQ群1: 276678893
可求档连环画,漫画;询问文本处理大师等软件使用技巧;求档softhub软件下载及使用技巧.
但不可"开车",严禁国家敏感话题,不可求档涉及版权的文档软件.
验证问题说明申请入群原因即可.
