1、为了更可靠与安全，一般都会产生一个key俗称密钥串来加密
2、准备好待加密的数据字符串text
3、将key与待加密字符串拼接处理，产生一个新的字符串str
4、将str按照一定编码处理成字节数组byte[]
5、利用md5的update方法处理字节数组获取加密后的值
用apache的实现示例：
/**
*签名字符串
*@paramtext需要签名的字符串
*@paramkey密钥
*@paraminput_charset编码格式
*@return签名结果
*/
publicstaticStringsign(Stringtext,Stringkey,Stringinput_charset){
text=text+key;
returnDigestUtils.md5Hex(getContentBytes(text,input_charset));
}
/**
*@paramcontent
*@paramcharset
*@return
*@throwsSignatureException
*@
*/
privatestaticbyte[]getContentBytes(Stringcontent,Stringcharset){
if(charset==null||"".equals(charset)){
returncontent.getBytes();
}
try{
returncontent.getBytes(charset);
}catch(UnsupportedEncodingExceptione){
thrownewRuntimeException("MD5签名过程中出现错误,指定的编码集不对,您目前指定的编码集是:"+charset);
}
}
⑵ JSP MD5加密解密问题。
package com.asset.core.util;
/**
* MD5 加密处理类
* @author 杨柯
* @version 1.0
*/
import java.lang.reflect.*;
/*************************************************
md5 类实现了RSA Data Security, Inc.在提交给IETF
的RFC1321中的MD5 message-digest 算法。
*************************************************/
public class MD5 {
/* 下面这些S11-S44实际上是一个4*4的矩阵，在原始的C实现中是用#define 实现的，
这里把它们实现成为static final是表示了只读，切能在同一个进程空间内的多个
Instance间共享*/
static final int S11 = 7;
static final int S12 = 12;
static final int S13 = 17;
static final int S14 = 22;
static final int S21 = 5;
static final int S22 = 9;
static final int S23 = 14;
static final int S24 = 20;
static final int S31 = 4;
static final int S32 = 11;
static final int S33 = 16;
static final int S34 = 23;
static final int S41 = 6;
static final int S42 = 10;
static final int S43 = 15;
static final int S44 = 21;
static final byte[] PADDING = { -128, 0, 0, 0, 0, 0, 0, 0, 0,
0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0 };
/* 下面的三个成员是MD5计算过程中用到的3个核心数据，在原始的C实现中
被定义到MD5_CTX结构中
*/
private long[] state = new long[4]; // state (ABCD)
private long[] count = new long[2]; // number of bits, molo 2^64 (lsb first)
private byte[] buffer = new byte[64]; // input buffer
/* digestHexStr是MD5的唯一一个公共成员，是最新一次计算结果的
16进制ASCII表示.
*/
public String digestHexStr;
/* digest,是最新一次计算结果的2进制内部表示，表示128bit的MD5值.
*/
private byte[] digest = new byte[16];
/*
getMD5ofStr是类MD5最主要的公共方法，入口参数是你想要进行MD5变换的字符串
返回的是变换完的结果，这个结果是从公共成员digestHexStr取得的．
*/
public String getMD5ofStr(String inbuf) {
md5Init();
md5Update(inbuf.getBytes(), inbuf.length());
md5Final();
digestHexStr = "";
for (int i = 0; i < 8; i++) {
digestHexStr += byteHEX(digest[i]);
}
return digestHexStr.substring(0,11);
}
// 这是MD5这个类的标准构造函数，JavaBean要求有一个public的并且没有参数的构造函数��
private MD5() {
md5Init();
return;
}
private static MD5 md5=new MD5();
public static MD5 getInstance(){
return MD5.md5;
}
/* md5Init是一个初始化函数，初始化核心变量，装入标准的幻数 */
private void md5Init() {
count[0] = 0L;
count[1] = 0L;
///* Load magic initialization constants.
state[0] = 0x67452301L;
state[1] = 0xefcdab89L;
state[2] = 0x98badcfeL;
state[3] = 0x10325476L;
return;
}
/* F, G, H ,I 是4个基本的MD5函数，在原始的MD5的C实现中，由于它们是
简单的位运算，可能出于效率的考虑把它们实现成了宏，在java中，我们把它们
实现成了private方法，名字保持了原来C中的。 */
private long F(long x, long y, long z) {
return (x & y) | ((~x) & z);
}
private long G(long x, long y, long z) {
return (x & z) | (y & (~z));
}
private long H(long x, long y, long z) {
return x ^ y ^ z;
}
private long I(long x, long y, long z) {
return y ^ (x | (~z));
}
/*
FF,GG,HH和II将调用F,G,H,I进行近一步变换
FF, GG, HH, and II transformations for rounds 1, 2, 3, and 4.
Rotation is separate from addition to prevent recomputation.
*/
private long FF(long a, long b, long c, long d, long x, long s,
long ac) {
a += F (b, c, d) + x + ac;
a = ((int) a << s) | ((int) a >>> (32 - s));
a += b;
return a;
}
private long GG(long a, long b, long c, long d, long x, long s,
long ac) {
a += G (b, c, d) + x + ac;
a = ((int) a << s) | ((int) a >>> (32 - s));
a += b;
return a;
}
private long HH(long a, long b, long c, long d, long x, long s,
long ac) {
a += H (b, c, d) + x + ac;
a = ((int) a << s) | ((int) a >>> (32 - s));
a += b;
return a;
}
private long II(long a, long b, long c, long d, long x, long s,
long ac) {
a += I (b, c, d) + x + ac;
a = ((int) a << s) | ((int) a >>> (32 - s));
a += b;
return a;
}
/*
md5Update是MD5的主计算过程，inbuf是要变换的字节串，inputlen是长度，这个
函数由getMD5ofStr调用，调用之前需要调用md5init，因此把它设计成private的
*/
private void md5Update(byte[] inbuf, int inputLen) {
int i, index, partLen;
byte[] block = new byte[64];
index = (int)(count[0] >>> 3) & 0x3F;
// /* Update number of bits */
if ((count[0] += (inputLen << 3)) < (inputLen << 3))
count[1]++;
count[1] += (inputLen >>> 29);
partLen = 64 - index;
// Transform as many times as possible.
if (inputLen >= partLen) {
md5Memcpy(buffer, inbuf, index, 0, partLen);
md5Transform(buffer);
for (i = partLen; i + 63 < inputLen; i += 64) {
md5Memcpy(block, inbuf, 0, i, 64);
md5Transform (block);
}
index = 0;
} else
i = 0;
///* Buffer remaining input */
md5Memcpy(buffer, inbuf, index, i, inputLen - i);
}
/*
md5Final整理和填写输出结果
*/
private void md5Final () {
byte[] bits = new byte[8];
int index, padLen;
///* Save number of bits */
Encode (bits, count, 8);
///* Pad out to 56 mod 64.
index = (int)(count[0] >>> 3) & 0x3f;
padLen = (index < 56) ? (56 - index) : (120 - index);
md5Update (PADDING, padLen);
///* Append length (before padding) */
md5Update(bits, 8);
///* Store state in digest */
Encode (digest, state, 16);
}
/* md5Memcpy是一个内部使用的byte数组的块拷贝函数，从input的inpos开始把len长度的
字节拷贝到output的outpos位置开始
*/
private void md5Memcpy (byte[] output, byte[] input,
int outpos, int inpos, int len)
{
int i;
for (i = 0; i < len; i++)
output[outpos + i] = input[inpos + i];
}
/*
md5Transform是MD5核心变换程序，有md5Update调用，block是分块的原始字节
*/
private void md5Transform (byte block[]) {
long a = state[0], b = state[1], c = state[2], d = state[3];
long[] x = new long[16];
Decode (x, block, 64);
/* Round 1 */
a = FF (a, b, c, d, x[0], S11, 0xd76aa478L); /* 1 */
d = FF (d, a, b, c, x[1], S12, 0xe8c7b756L); /* 2 */
c = FF (c, d, a, b, x[2], S13, 0x242070dbL); /* 3 */
b = FF (b, c, d, a, x[3], S14, 0xc1bdceeeL); /* 4 */
a = FF (a, b, c, d, x[4], S11, 0xf57c0fafL); /* 5 */
d = FF (d, a, b, c, x[5], S12, 0x4787c62aL); /* 6 */
c = FF (c, d, a, b, x[6], S13, 0xa8304613L); /* 7 */
b = FF (b, c, d, a, x[7], S14, 0xfd469501L); /* 8 */
a = FF (a, b, c, d, x[8], S11, 0x698098d8L); /* 9 */
d = FF (d, a, b, c, x[9], S12, 0x8b44f7afL); /* 10 */
c = FF (c, d, a, b, x[10], S13, 0xffff5bb1L); /* 11 */
b = FF (b, c, d, a, x[11], S14, 0x895cd7beL); /* 12 */
a = FF (a, b, c, d, x[12], S11, 0x6b901122L); /* 13 */
d = FF (d, a, b, c, x[13], S12, 0xfd987193L); /* 14 */
c = FF (c, d, a, b, x[14], S13, 0xa679438eL); /* 15 */
b = FF (b, c, d, a, x[15], S14, 0x49b40821L); /* 16 */
/* Round 2 */
a = GG (a, b, c, d, x[1], S21, 0xf61e2562L); /* 17 */
d = GG (d, a, b, c, x[6], S22, 0xc040b340L); /* 18 */
c = GG (c, d, a, b, x[11], S23, 0x265e5a51L); /* 19 */
b = GG (b, c, d, a, x[0], S24, 0xe9b6c7aaL); /* 20 */
a = GG (a, b, c, d, x[5], S21, 0xd62f105dL); /* 21 */
d = GG (d, a, b, c, x[10], S22, 0x2441453L); /* 22 */
c = GG (c, d, a, b, x[15], S23, 0xd8a1e681L); /* 23 */
b = GG (b, c, d, a, x[4], S24, 0xe7d3fbc8L); /* 24 */
a = GG (a, b, c, d, x[9], S21, 0x21e1cde6L); /* 25 */
d = GG (d, a, b, c, x[14], S22, 0xc33707d6L); /* 26 */
c = GG (c, d, a, b, x[3], S23, 0xf4d50d87L); /* 27 */
b = GG (b, c, d, a, x[8], S24, 0x455a14edL); /* 28 */
a = GG (a, b, c, d, x[13], S21, 0xa9e3e905L); /* 29 */
d = GG (d, a, b, c, x[2], S22, 0xfcefa3f8L); /* 30 */
c = GG (c, d, a, b, x[7], S23, 0x676f02d9L); /* 31 */
b = GG (b, c, d, a, x[12], S24, 0x8d2a4c8aL); /* 32 */
/* Round 3 */
a = HH (a, b, c, d, x[5], S31, 0xfffa3942L); /* 33 */
d = HH (d, a, b, c, x[8], S32, 0x8771f681L); /* 34 */
c = HH (c, d, a, b, x[11], S33, 0x6d9d6122L); /* 35 */
b = HH (b, c, d, a, x[14], S34, 0xfde5380cL); /* 36 */
a = HH (a, b, c, d, x[1], S31, 0xa4beea44L); /* 37 */
d = HH (d, a, b, c, x[4], S32, 0x4bdecfa9L); /* 38 */
c = HH (c, d, a, b, x[7], S33, 0xf6bb4b60L); /* 39 */
b = HH (b, c, d, a, x[10], S34, 0xbebfbc70L); /* 40 */
a = HH (a, b, c, d, x[13], S31, 0x289b7ec6L); /* 41 */
d = HH (d, a, b, c, x[0], S32, 0xeaa127faL); /* 42 */
c = HH (c, d, a, b, x[3], S33, 0xd4ef3085L); /* 43 */
b = HH (b, c, d, a, x[6], S34, 0x4881d05L); /* 44 */
a = HH (a, b, c, d, x[9], S31, 0xd9d4d039L); /* 45 */
d = HH (d, a, b, c, x[12], S32, 0xe6db99e5L); /* 46 */
c = HH (c, d, a, b, x[15], S33, 0x1fa27cf8L); /* 47 */
b = HH (b, c, d, a, x[2], S34, 0xc4ac5665L); /* 48 */
/* Round 4 */
a = II (a, b, c, d, x[0], S41, 0xf4292244L); /* 49 */
d = II (d, a, b, c, x[7], S42, 0x432aff97L); /* 50 */
c = II (c, d, a, b, x[14], S43, 0xab9423a7L); /* 51 */
b = II (b, c, d, a, x[5], S44, 0xfc93a039L); /* 52 */
a = II (a, b, c, d, x[12], S41, 0x655b59c3L); /* 53 */
d = II (d, a, b, c, x[3], S42, 0x8f0ccc92L); /* 54 */
c = II (c, d, a, b, x[10], S43, 0xffeff47dL); /* 55 */
b = II (b, c, d, a, x[1], S44, 0x85845dd1L); /* 56 */
a = II (a, b, c, d, x[8], S41, 0x6fa87e4fL); /* 57 */
d = II (d, a, b, c, x[15], S42, 0xfe2ce6e0L); /* 58 */
c = II (c, d, a, b, x[6], S43, 0xa3014314L); /* 59 */
b = II (b, c, d, a, x[13], S44, 0x4e0811a1L); /* 60 */
a = II (a, b, c, d, x[4], S41, 0xf7537e82L); /* 61 */
d = II (d, a, b, c, x[11], S42, 0xbd3af235L); /* 62 */
c = II (c, d, a, b, x[2], S43, 0x2ad7d2bbL); /* 63 */
b = II (b, c, d, a, x[9], S44, 0xeb86d391L); /* 64 */
state[0] += a;
state[1] += b;
state[2] += c;
state[3] += d;
}
/*Encode把long数组按顺序拆成byte数组，因为java的long类型是64bit的，
只拆低32bit，以适应原始C实现的用途
*/
private void Encode (byte[] output, long[] input, int len) {
int i, j;
for (i = 0, j = 0; j < len; i++, j += 4) {
output[j] = (byte)(input[i] & 0xffL);
output[j + 1] = (byte)((input[i] >>> 8) & 0xffL);
output[j + 2] = (byte)((input[i] >>> 16) & 0xffL);
output[j + 3] = (byte)((input[i] >>> 24) & 0xffL);
}
}
/*Decode把byte数组按顺序合成成long数组，因为java的long类型是64bit的，
只合成低32bit，高32bit清零，以适应原始C实现的用途
*/
private void Decode (long[] output, byte[] input, int len) {
int i, j;
for (i = 0, j = 0; j < len; i++, j += 4)
output[i] = b2iu(input[j]) |
(b2iu(input[j + 1]) << 8) |
(b2iu(input[j + 2]) << 16) |
(b2iu(input[j + 3]) << 24);
return;
}
/*
b2iu是我写的一个把byte按照不考虑正负号的原则的＂升位＂程序，因为java没有unsigned运算
*/
public static long b2iu(byte b) {
return b < 0 ? b & 0x7F + 128 : b;
}
/*byteHEX()，用来把一个byte类型的数转换成十六进制的ASCII表示，
因为java中的byte的toString无法实现这一点，我们又没有C语言中的
sprintf(outbuf,"%02X",ib)
*/
public static String byteHEX(byte ib) {
char[] Digit = { '0','1','2','3','4','5','6','7','8','9',
'A','B','C','D','E','F' };
char [] ob = new char[2];
ob[0] = Digit[(ib >>> 4) & 0X0F];
ob[1] = Digit[ib & 0X0F];
String s = new String(ob);
return s;
}
public static void main(String args[]) {
MD5 m = new MD5();
if (Array.getLength(args) == 0) { //如果没有参数，执行标准的Test Suiteִ�б���Test Suite
System.out.println("MD5 Test suite:");
System.out.println("MD5(\"\"):"+m.getMD5ofStr(""));
System.out.println("admin: "+m.getMD5ofStr("admin"));
System.out.println("MD5(\"a\"):"+m.getMD5ofStr("a"));
System.out.println("MD5(\"abc\"):"+m.getMD5ofStr("abc"));
System.out.println("MD5(\"message digest\"):"+m.getMD5ofStr("message digest"));
System.out.println("MD5(\"abcdefghijklmnopqrstuvwxyz\"):"+
m.getMD5ofStr("abcdefghijklmnopqrstuvwxyz"));
System.out.println("MD5(\"\"):"+
m.getMD5ofStr(""));
}
else
System.out.println("MD5(" + args[0] + ")=" + m.getMD5ofStr(args[0]));
}
}
⑶ java中，从数据库取出来的密码加密了，用代码怎么实现md5解密
md5是不可逆的，只不过用的人多了，就有人创建了一个md5密码表，应该就是传说中的彩虹表，蜜要是有这个表就可以了
⑷ 求Java的MD5加密解密实现类。 要实现对用户的密码进行加密！ 然后验证用户的密码！
import java.security.*;
import java.util.logging.Level;
import java.util.logging.Logger;
public class md5{
public String md5(String str) {
String s=str;
if(s==null){
return "";
}else{
String value = null;
MessageDigest md5 = null;
try {
md5 = MessageDigest.getInstance("MD5");
}catch (NoSuchAlgorithmException ex) {
Logger.getLogger(md5.class.getName()).log(Level.SEVERE, null, ex);
}
sun.misc.BASE64Encoder baseEncoder = new sun.misc.BASE64Encoder();
try {
value = baseEncoder.encode(md5.digest(s.getBytes("utf-8")));
} catch (Exception ex) {
}
return value;
}
}
}
⑸ java 如何采用md5解密
md5只是消息摘要，不管来多长自的数据均得到512比特的摘要。
所以md5一般用于验证，原始消息被修改后，md5的消息摘要会有变化。
md5不是用于加密，也就不能解密，因为有无穷多的数据对应同一个md5消息摘要
⑹ 求java加密源代码（MD5，base64）
import java.security.*;
import javax.crypto.*;
/**
* 本例解释如何利用DES私钥加密算法加解密
*
* @author Devon
* @version 1.0 04/03/10
*/
public class SingleKeyExample {
public static void main(String[] args) {
try {
String algorithm = "DES"; //定义加密算法,可用 DES,DESede,Blowfish
String message = "Hello World. 这是待加密的信息";
// 生成个DES密钥
KeyGenerator keyGenerator = KeyGenerator.getInstance(algorithm);
keyGenerator.init(56); //选择DES算法,密钥长度必须为56位
Key key = keyGenerator.generateKey(); //生成密钥
// 生成Cipher对象
Cipher cipher = Cipher.getInstance("DES");
//用密钥加密明文(message),生成密文(cipherText)
cipher.init(Cipher.ENCRYPT_MODE, key); //操作模式为加密(Cipher.ENCRYPT_MODE),key为密钥
byte[] cipherText = cipher.doFinal(message.getBytes()); //得到加密后的字节数组
System.out.println("加密后的信息: " + new String(cipherText));
//用密钥加密明文(plainText),生成密文(cipherByte)
cipher.init(Cipher.DECRYPT_MODE, key); //操作模式为解密,key为密钥
byte[] sourceText = cipher.doFinal(cipherText); //获得解密后字节数组
System.out.println("解密后的信息: " + new String(sourceText));
} catch (Exception ex) {
ex.printStackTrace();
}
}
}
/**
* @author Devon
*/
import java.security.*;
import java.security.spec.*;
import javax.crypto.*;
public class PairKeyExample {
public static void main(String argv[]) {
try {
String algorithm = "RSA"; //定义加密算法,可用 DES,DESede,Blowfish
String message = "张三，你好，我是李四";
//产生张三的密钥对(keyPairZhang)
KeyPairGenerator keyGeneratorZhang =
KeyPairGenerator.getInstance(algorithm); //指定采用的算法
keyGeneratorZhang.initialize(1024); //指定密钥长度为1024位
KeyPair keyPairZhang = keyGeneratorZhang.generateKeyPair(); //产生密钥对
System.out.println("生成张三的公钥对");
// 张三生成公钥(publicKeyZhang)并发送给李四,这里发送的是公钥的数组字节
byte[] publicKeyZhangEncode = keyPairZhang.getPublic().getEncoded();
//通过网络或磁盘等方式,把公钥编码传送给李四
//李四接收到张三编码后的公钥,将其解码
KeyFactory keyFacoryLi = KeyFactory.getInstance(algorithm); //得到KeyFactory对象
X509EncodedKeySpec x509KeySpec =
new X509EncodedKeySpec(publicKeyZhangEncode); //公钥采用X.509编码
PublicKey publicKeyZhang = keyFacoryLi.generatePublic(x509KeySpec); //将公钥的KeySpec对象转换为公钥
System.out.println("李四成功解码,得到张三的公钥");
//李四用张三的公钥加密信息，并发送给李四
Cipher cipher = Cipher.getInstance("RSA/ECB/PKCS1Padding"); //得到Cipher对象
cipher.init(Cipher.ENCRYPT_MODE, publicKeyZhang); //用张三的公钥初始化Cipher对象
byte[] cipherMessage = cipher.doFinal(message.getBytes()); //得到加密信息
System.out.println("加密后信息：" + new String(cipherMessage));
System.out.println("加密完成，发送给李四...");
//张三用自己的私钥解密从李四处收到的信息
cipher.init(Cipher.DECRYPT_MODE, keyPairZhang.getPrivate()); //张三用其私钥初始化Cipher对象
byte[] originalMessage = cipher.doFinal(cipherMessage); //得到解密后信息
System.out.println("张三收到信息，解密后为：" + new String(originalMessage));
} catch (Exception ex) {
ex.printStackTrace();
}
}
}
⑺ java中DES、MD5加密算法在哪个包中如何分别调用这两个方法实现对输入数据的加密、解密
java.security.MessageDigest
/*
*MD5算法
*/
publicclassMD5{
//全局数组
privatefinalstaticString[]strDigits={"0","1","2","3","4","5",
"6","7","8","9","a","b","c","d","e","f"};
publicMD5(){
}
//返回形式为数字跟字符串
(bytebByte){
intiRet=bByte;
//System.out.println("iRet="+iRet);
if(iRet<0){
iRet+=256;
}
intiD1=iRet/16;
intiD2=iRet%16;
returnstrDigits[iD1]+strDigits[iD2];
}
//返回形式只为数字
privatestaticStringbyteToNum(bytebByte){
intiRet=bByte;
System.out.println("iRet1="+iRet);
if(iRet<0){
iRet+=256;
}
returnString.valueOf(iRet);
}
//转换字节数组为16进制字串
(byte[]bByte){
StringBuffersBuffer=newStringBuffer();
for(inti=0;i<bByte.length;i++){
sBuffer.append(byteToArrayString(bByte[i]));
}
returnsBuffer.toString();
}
publicstaticStringGetMD5Code(StringstrObj){
StringresultString=null;
try{
resultString=newString(strObj);
MessageDigestmd=MessageDigest.getInstance("MD5");
//md.digest()该函数返回值为存放哈希值结果的byte数组
resultString=byteToString(md.digest(strObj.getBytes()));
}catch(NoSuchAlgorithmExceptionex){
ex.printStackTrace();
}
returnresultString;
}
publicstaticvoidmain(String[]args){
MD5getMD5=newMD5();
System.out.println(getMD5.GetMD5Code("000000"));
}
}
⑻ 如何在java中实现md5加密和解密
package endecrypt;
02.
03.import java.io.UnsupportedEncodingException;
04.import java.security.MessageDigest;
05.import java.security.NoSuchAlgorithmException;
06.
07./**
08. * 采用MD5加密解密
09. * @author tfq
10. * @datetime 2011-10-13
11. */
12.public class MD5Util {
13.
14. /***
15. * MD5加码 生成32位md5码
16. */
17. public static String string2MD5(String inStr){
18. MessageDigest md5 = null;
19. try{
20. md5 = MessageDigest.getInstance("MD5");
21. }catch (Exception e){
22. System.out.println(e.toString());
23. e.printStackTrace();
24. return "";
25. }
26. char[] charArray = inStr.toCharArray();
27. byte[] byteArray = new byte[charArray.length];
28.
29. for (int i = 0; i < charArray.length; i++)
30. byteArray[i] = (byte) charArray[i];
31. byte[] md5Bytes = md5.digest(byteArray);
32. StringBuffer hexValue = new StringBuffer();
33. for (int i = 0; i < md5Bytes.length; i++){
34. int val = ((int) md5Bytes[i]) & 0xff;
35. if (val < 16)
36. hexValue.append("0");
37. hexValue.append(Integer.toHexString(val));
38. }
39. return hexValue.toString();
40.
41. }
42.
43. /**
44. * 加密解密算法 执行一次加密，两次解密
45. */
46. public static String convertMD5(String inStr){
47.
48. char[] a = inStr.toCharArray();
49. for (int i = 0; i < a.length; i++){
50. a[i] = (char) (a[i] ^ 't');
51. }
52. String s = new String(a);
53. return s;
54.
55. }
⑼ Java MD5如何解密
MD5 不能解密, MD5的破解方式就是 把不同的字符串按MD5加密 然后对比加密后的结果是不是一样. 在线MD5解密 也是这样的原理.
⑽ java加密解密代码
package com.cube.limail.util;
import javax.crypto.Cipher;
import javax.crypto.KeyGenerator;
import javax.crypto.SecretKey;/**
* 加密解密类
*/
public class Eryptogram
{
private static String Algorithm ="DES";
private String key="CB7A92E3D3491964";
//定义 加密算法,可用 DES,DESede,Blowfish
static boolean debug = false ;
/**
* 构造子注解.
*/
public Eryptogram ()
{
} /**
* 生成密钥
* @return byte[] 返回生成的密钥
* @throws exception 扔出异常.
*/
public static byte [] getSecretKey () throws Exception
{
KeyGenerator keygen = KeyGenerator.getInstance (Algorithm );
SecretKey deskey = keygen.generateKey ();
System.out.println ("生成密钥:"+bytesToHexString (deskey.getEncoded ()));
if (debug ) System.out.println ("生成密钥:"+bytesToHexString (deskey.getEncoded ()));
return deskey.getEncoded ();
} /**
* 将指定的数据根据提供的密钥进行加密
* @param input 需要加密的数据
* @param key 密钥
* @return byte[] 加密后的数据
* @throws Exception
*/
public static byte [] encryptData (byte [] input ,byte [] key ) throws Exception
{
SecretKey deskey = new javax.crypto.spec.SecretKeySpec (key ,Algorithm );
if (debug )
{
System.out.println ("加密前的二进串:"+byte2hex (input ));
System.out.println ("加密前的字符串:"+new String (input ));
} Cipher c1 = Cipher.getInstance (Algorithm );
c1.init (Cipher.ENCRYPT_MODE ,deskey );
byte [] cipherByte =c1.doFinal (input );
if (debug ) System.out.println ("加密后的二进串:"+byte2hex (cipherByte ));
return cipherByte ;
} /**
* 将给定的已加密的数据通过指定的密钥进行解密
* @param input 待解密的数据
* @param key 密钥
* @return byte[] 解密后的数据
* @throws Exception
*/
public static byte [] decryptData (byte [] input ,byte [] key ) throws Exception
{
SecretKey deskey = new javax.crypto.spec.SecretKeySpec (key ,Algorithm );
if (debug ) System.out.println ("解密前的信息:"+byte2hex (input ));
Cipher c1 = Cipher.getInstance (Algorithm );
c1.init (Cipher.DECRYPT_MODE ,deskey );
byte [] clearByte =c1.doFinal (input );
if (debug )
{
System.out.println ("解密后的二进串:"+byte2hex (clearByte ));
System.out.println ("解密后的字符串:"+(new String (clearByte )));
} return clearByte ;
} /**
* 字节码转换成16进制字符串
* @param byte[] b 输入要转换的字节码
* @return String 返回转换后的16进制字符串
*/
public static String byte2hex (byte [] b )
{
String hs ="";
String stmp ="";
for (int n =0 ;n <b.length ;n ++)
{
stmp =(java.lang.Integer.toHexString (b [n ] & 0XFF ));
if (stmp.length ()==1 ) hs =hs +"0"+stmp ;
else hs =hs +stmp ;
if (n <b.length -1 ) hs =hs +":";
} return hs.toUpperCase ();
}
/**
* 字符串转成字节数组.
* @param hex 要转化的字符串.
* @return byte[] 返回转化后的字符串.
*/
public static byte[] hexStringToByte(String hex) {
int len = (hex.length() / 2);
byte[] result = new byte[len];
char[] achar = hex.toCharArray();
for (int i = 0; i < len; i++) {
int pos = i * 2;
result[i] = (byte) (toByte(achar[pos]) << 4 | toByte(achar[pos + 1]));
}
return result;
}
private static byte toByte(char c) {
byte b = (byte) "0123456789ABCDEF".indexOf(c);
return b;
}
/**
* 字节数组转成字符串.
* @param String 要转化的字符串.
* @return 返回转化后的字节数组.
*/
public static final String bytesToHexString(byte[] bArray) {
StringBuffer sb = new StringBuffer(bArray.length);
String sTemp;
for (int i = 0; i < bArray.length; i++) {
sTemp = Integer.toHexString(0xFF & bArray[i]);
if (sTemp.length() < 2)
sb.append(0);
sb.append(sTemp.toUpperCase());
}
return sb.toString();
}
/**
* 从数据库中获取密钥.
* @param deptid 企业id.
* @return 要返回的字节数组.
* @throws Exception 可能抛出的异常.
*/
public static byte[] getSecretKey(long deptid) throws Exception {
byte[] key=null;
String value=null;
//CommDao =new CommDao();
// List list=.getRecordList("from Key k where k.deptid="+deptid);
//if(list.size()>0){
//value=((com.csc.sale.bean.Key)list.get(0)).getKey();
value = "CB7A92E3D3491964";
key=hexStringToByte(value);
//}
if (debug)
System.out.println("密钥:" + value);
return key;
}
public String encryptData2(String data) {
String en = null;
try {
byte[] key=hexStringToByte(this.key);
en = bytesToHexString(encryptData(data.getBytes(),key));
} catch (Exception e) {
e.printStackTrace();
}
return en;
}
public String decryptData2(String data) {
String de = null;
try {
byte[] key=hexStringToByte(this.key);
de = new String(decryptData(hexStringToByte(data),key));
} catch (Exception e) {
e.printStackTrace();
}
return de;
}
} 加密使用： byte[] key=Eryptogram.getSecretKey(deptid); //获得钥匙（字节数组）
byte[] tmp=Eryptogram.encryptData(password.getBytes(), key); //传入密码和钥匙，获得加密后的字节数组的密码
password=Eryptogram.bytesToHexString(tmp); //将字节数组转化为字符串，获得加密后的字符串密码解密与之差不多