如何使用Java解码/解密MD5加密
我正在使用ExtJS框架。 我在JavaScript中有一个MD5函数来加密一些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？
这是我正在使用的JS等效的MD5function：
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 <>> (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 <>> 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 >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 >5] >>> (i % 32)) & mask); } return str; } function binl2hex(binarray){ var hex_tab = hexcase ? "0123456789ABCDEF" : "0123456789abcdef"; var str = ""; for(var i = 0; 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)) ); }; MD5是一个哈希 （即单向转换），因此您无法对其进行解密。 您可以将已知散列与从明文计算的散列进行比较，以validation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validation在javascript中生成的哈希值具有相同的编码。
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(); } } }