如何使用Java解码/解密MD5加密 [英] How to decode/decrypt MD5 encryption using Java
本文介绍了如何使用Java解码/解密MD5加密的处理方法，对大家解决问题具有一定的参考价值，需要的朋友们下面随着小编来一起学习吧！
问题描述
我正在使用ExtJS框架。我在 JavaScript 中使用了MD5功能来加密某些JSON。我的后端使用Java，所以我想知道如何使用 Java 解密MD5 Javascript加密？
I am using the ExtJS framework. I have a MD5 function in JavaScript to encrypt some JSON. My backend uses Java so I wanted to know how to decrypt an MD5 Javascript encryption using Java?
这是我正在使用的JS等效的MD5函数：
Here is the JS equiv of MD5 function that I am using:
Ext.util.MD5 = function(s,raw,hexcase,chrsz) {
raw = raw || false;
hexcase = hexcase || false;
chrsz = chrsz || 8;
function safe_add(x, y){
var lsw = (x & 0xFFFF) + (y & 0xFFFF);
var msw = (x >> 16) + (y >> 16) + (lsw >> 16);
return (msw << 16) | (lsw & 0xFFFF);
}
function bit_rol(num, cnt){
return (num << cnt) | (num >>> (32 - cnt));
}
function md5_cmn(q, a, b, x, s, t){
return safe_add(bit_rol(safe_add(safe_add(a, q), safe_add(x, t)), s),b);
}
function md5_ff(a, b, c, d, x, s, t){
return md5_cmn((b & c) | ((~b) & d), a, b, x, s, t);
}
function md5_gg(a, b, c, d, x, s, t){
return md5_cmn((b & d) | (c & (~d)), a, b, x, s, t);
}
function md5_hh(a, b, c, d, x, s, t){
return md5_cmn(b ^ c ^ d, a, b, x, s, t);
}
function md5_ii(a, b, c, d, x, s, t){
return md5_cmn(c ^ (b | (~d)), a, b, x, s, t);
}
function core_md5(x, len){
x[len >> 5] |= 0x80 << ((len) % 32);
x[(((len + 64) >>> 9) << 4) + 14] = len;
var a = 1732584193;
var b = -271733879;
var c = -1732584194;
var d = 271733878;
for(var i = 0; i < x.length; i += 16){
var olda = a;
var oldb = b;
var oldc = c;
var oldd = d;
a = md5_ff(a, b, c, d, x[i+ 0], 7 , -680876936);
d = md5_ff(d, a, b, c, x[i+ 1], 12, -389564586);
c = md5_ff(c, d, a, b, x[i+ 2], 17, 606105819);
b = md5_ff(b, c, d, a, x[i+ 3], 22, -1044525330);
a = md5_ff(a, b, c, d, x[i+ 4], 7 , -176418897);
d = md5_ff(d, a, b, c, x[i+ 5], 12, 1200080426);
c = md5_ff(c, d, a, b, x[i+ 6], 17, -1473231341);
b = md5_ff(b, c, d, a, x[i+ 7], 22, -45705983);
a = md5_ff(a, b, c, d, x[i+ 8], 7 , 1770035416);
d = md5_ff(d, a, b, c, x[i+ 9], 12, -1958414417);
c = md5_ff(c, d, a, b, x[i+10], 17, -42063);
b = md5_ff(b, c, d, a, x[i+11], 22, -1990404162);
a = md5_ff(a, b, c, d, x[i+12], 7 , 1804603682);
d = md5_ff(d, a, b, c, x[i+13], 12, -40341101);
c = md5_ff(c, d, a, b, x[i+14], 17, -1502002290);
b = md5_ff(b, c, d, a, x[i+15], 22, 1236535329);
a = md5_gg(a, b, c, d, x[i+ 1], 5 , -165796510);
d = md5_gg(d, a, b, c, x[i+ 6], 9 , -1069501632);
c = md5_gg(c, d, a, b, x[i+11], 14, 643717713);
b = md5_gg(b, c, d, a, x[i+ 0], 20, -373897302);
a = md5_gg(a, b, c, d, x[i+ 5], 5 , -701558691);
d = md5_gg(d, a, b, c, x[i+10], 9 , 38016083);
c = md5_gg(c, d, a, b, x[i+15], 14, -660478335);
b = md5_gg(b, c, d, a, x[i+ 4], 20, -405537848);
a = md5_gg(a, b, c, d, x[i+ 9], 5 , 568446438);
d = md5_gg(d, a, b, c, x[i+14], 9 , -1019803690);
c = md5_gg(c, d, a, b, x[i+ 3], 14, -187363961);
b = md5_gg(b, c, d, a, x[i+ 8], 20, 1163531501);
a = md5_gg(a, b, c, d, x[i+13], 5 , -1444681467);
d = md5_gg(d, a, b, c, x[i+ 2], 9 , -51403784);
c = md5_gg(c, d, a, b, x[i+ 7], 14, 1735328473);
b = md5_gg(b, c, d, a, x[i+12], 20, -1926607734);
a = md5_hh(a, b, c, d, x[i+ 5], 4 , -378558);
d = md5_hh(d, a, b, c, x[i+ 8], 11, -2022574463);
c = md5_hh(c, d, a, b, x[i+11], 16, 1839030562);
b = md5_hh(b, c, d, a, x[i+14], 23, -35309556);
a = md5_hh(a, b, c, d, x[i+ 1], 4 , -1530992060);
d = md5_hh(d, a, b, c, x[i+ 4], 11, 1272893353);
c = md5_hh(c, d, a, b, x[i+ 7], 16, -155497632);
b = md5_hh(b, c, d, a, x[i+10], 23, -1094730640);
a = md5_hh(a, b, c, d, x[i+13], 4 , 681279174);
d = md5_hh(d, a, b, c, x[i+ 0], 11, -358537222);
c = md5_hh(c, d, a, b, x[i+ 3], 16, -722521979);
b = md5_hh(b, c, d, a, x[i+ 6], 23, 76029189);
a = md5_hh(a, b, c, d, x[i+ 9], 4 , -640364487);
d = md5_hh(d, a, b, c, x[i+12], 11, -421815835);
c = md5_hh(c, d, a, b, x[i+15], 16, 530742520);
b = md5_hh(b, c, d, a, x[i+ 2], 23, -995338651);
a = md5_ii(a, b, c, d, x[i+ 0], 6 , -198630844);
d = md5_ii(d, a, b, c, x[i+ 7], 10, 1126891415);
c = md5_ii(c, d, a, b, x[i+14], 15, -1416354905);
b = md5_ii(b, c, d, a, x[i+ 5], 21, -57434055);
a = md5_ii(a, b, c, d, x[i+12], 6 , 1700485571);
d = md5_ii(d, a, b, c, x[i+ 3], 10, -1894986606);
c = md5_ii(c, d, a, b, x[i+10], 15, -1051523);
b = md5_ii(b, c, d, a, x[i+ 1], 21, -2054922799);
a = md5_ii(a, b, c, d, x[i+ 8], 6 , 1873313359);
d = md5_ii(d, a, b, c, x[i+15], 10, -30611744);
c = md5_ii(c, d, a, b, x[i+ 6], 15, -1560198380);
b = md5_ii(b, c, d, a, x[i+13], 21, 1309151649);
a = md5_ii(a, b, c, d, x[i+ 4], 6 , -145523070);
d = md5_ii(d, a, b, c, x[i+11], 10, -1120210379);
c = md5_ii(c, d, a, b, x[i+ 2], 15, 718787259);
b = md5_ii(b, c, d, a, x[i+ 9], 21, -343485551);
a = safe_add(a, olda);
b = safe_add(b, oldb);
c = safe_add(c, oldc);
d = safe_add(d, oldd);
}
return [a, b, c, d];
}
function str2binl(str){
var bin = [];
var mask = (1 << chrsz) - 1;
for(var i = 0; i < str.length * chrsz; i += chrsz) {
bin[i>>5] |= (str.charCodeAt(i / chrsz) & mask) << (i%32);
}
return bin;
}
function binl2str(bin){
var str = "";
var mask = (1 << chrsz) - 1;
for(var i = 0; i < bin.length * 32; i += chrsz) {
str += String.fromCharCode((bin[i>>5] >>> (i % 32)) & mask);
}
return str;
}
function binl2hex(binarray){
var hex_tab = hexcase ? "0123456789ABCDEF" : "0123456789abcdef";
var str = "";
for(var i = 0; i < binarray.length * 4; i++) {
str += hex_tab.charAt((binarray[i>>2] >> ((i%4)*8+4)) & 0xF) + hex_tab.charAt((binarray[i>>2] >> ((i%4)*8 )) & 0xF);
}
return str;
}
return (raw ? binl2str(core_md5(str2binl(s), s.length * chrsz)) : binl2hex(core_md5(str2binl(s), s.length * chrsz)) );
};
推荐答案
MD5是哈希 （即单向转换），所以你不能解密它。您可以将已知散列与从明文计算的散列进行比较，以验证输入的有效性。 Java有内置的库。我已经使用下面的代码，根据需要进行调整，还验证在javascript中生成的哈希值具有相同的编码。
MD5 is a hash (i.e. one-way transformation), so you can't decrypt it. You can compare a known hash with hash computed from a cleartext to verify validity of input. Java has inbuilt library for this. I have used this code below, adapt as necessary, also verify that your hashes generated in javascript have the same encoding.
import java.security.MessageDigest;
import sun.misc.BASE64Encoder;
public class MD5Sample {
/**
* Cipher for encode
*/
private final MessageDigest md;
public MD5Sample() throws SecurityException {
try {
md = MessageDigest.getInstance("MD5", "SUN");
}catch(Exception se) {
throw new SecurityException("In MD5 constructor " + se);
}
}
public String encode(String in) throws Exception {
if (in == null) {
return null;
}
try {
byte[] raw = null;
byte[] stringBytes = null;
stringBytes = in.getBytes("UTF8");
synchronized(md) {
raw = md.digest(stringBytes);
}
BASE64Encoder encoder = new BASE64Encoder();
return encoder.encode(raw);
} catch (Exception se) {
throw new Exception("Exception while encoding " + se);
}
}
public String decode(String in) {
throw new RuntimeException("NOT SUPPORTED");
}
/**
* Test harness
* @param args
*/
public static void main(String[] args) {
String clearText = "apple";
try {
MD5Sample app = new MD5Sample();
String encryptedHash = app.encode(clearText);
System.out.println(encryptedHash);
} catch (Exception e) {
e.printStackTrace();
}
}
}
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