javascript+Java 實現MD5加密登入密碼

客戶說我的***系統登入時密碼是明文傳輸，不高興，我對HTTPS不太瞭解，那我用MD5加密下，雖然不能保證萬無一失，但也好過明文傳輸嘛。

說下大概的過程：開啟登入的JSP頁面時，產生一個隨機字串，放在session裡面，以便後台也可以拿到。客戶輸入使用者名稱和密碼點擊"登入"時，拿到密碼和隨機字串，拼接在一起後利用js產生MD5字串。然後用js把那個password的value改成MD5字串，再提交表單。

後台拿到隨機字串和使用者名稱和MD5字串，通過使用者名稱到資料庫查詢密碼，用密碼和隨機字串拼接在一起產生MD5字串，用產生的MD5字串和前台傳過來的MD5字串進行匹配，如果一致就通過驗證。

------------------------------前台-------------------------------------

jsp頁面產生隨機數：

<%String pageName = pageContext.getRequest().getParameter("pageName");pageName = StringUtils.filterUnsafeChars(pageName); //業務系統內部的一個過濾操作，可以跳過這一步//產生隨機數，和密碼一起產生MD5request.getSession().setAttribute("md5RandomKey", StringUtils.getRandomNum(10));%>

表單submit時調用下面的函數：

function encryptionPassword(){               var hash = MD5($("user_password").value+"${md5RandomKey}");       $("user_password").value = hash;      } 

md5.js如下：

/* * A JavaScript implementation of the RSA Data Security, Inc. MD5 Message * Digest Algorithm, as defined in RFC 1321. * Copyright (C) Paul Johnston 1999 - 2000. * Updated by Greg Holt 2000 - 2001. * See http://pajhome.org.uk/site/legal.html for details. */var hex_chr = "0123456789abcdef";function rhex(num) {str = "";for (j = 0; j <= 3; j++) {str += hex_chr.charAt((num >> (j * 8 + 4)) & 15) + hex_chr.charAt((num >> (j * 8)) & 15);}return str;}function str2blks_MD5(str) {nblk = ((str.length + 8) >> 6) + 1;blks = new Array(nblk * 16);for (i = 0; i < nblk * 16; i++) {blks[i] = 0;}for (i = 0; i < str.length; i++) {blks[i >> 2] |= str.charCodeAt(i) << ((i % 4) * 8);}blks[i >> 2] |= 128 << ((i % 4) * 8);blks[nblk * 16 - 2] = str.length * 8;return blks;}function add(x, y) {var lsw = (x & 65535) + (y & 65535);var msw = (x >> 16) + (y >> 16) + (lsw >> 16);return (msw << 16) | (lsw & 65535);}function rol(num, cnt) {return (num << cnt) | (num >>> (32 - cnt));}function cmn(q, a, b, x, s, t) {return add(rol(add(add(a, q), add(x, t)), s), b);}function ff(a, b, c, d, x, s, t) {return cmn((b & c) | ((~b) & d), a, b, x, s, t);}function gg(a, b, c, d, x, s, t) {return cmn((b & d) | (c & (~d)), a, b, x, s, t);}function hh(a, b, c, d, x, s, t) {return cmn(b ^ c ^ d, a, b, x, s, t);}function ii(a, b, c, d, x, s, t) {return cmn(c ^ (b | (~d)), a, b, x, s, t);}function MD5(str) {x = str2blks_MD5(str);var a = 1732584193;var b = -271733879;var c = -1732584194;var d = 271733878;for (i = 0; i < x.length; i += 16) {var olda = a;var oldb = b;var oldc = c;var oldd = d;a = ff(a, b, c, d, x[i + 0], 7, -680876936);d = ff(d, a, b, c, x[i + 1], 12, -389564586);c = ff(c, d, a, b, x[i + 2], 17, 606105819);b = ff(b, c, d, a, x[i + 3], 22, -1044525330);a = ff(a, b, c, d, x[i + 4], 7, -176418897);d = ff(d, a, b, c, x[i + 5], 12, 1200080426);c = ff(c, d, a, b, x[i + 6], 17, -1473231341);b = ff(b, c, d, a, x[i + 7], 22, -45705983);a = ff(a, b, c, d, x[i + 8], 7, 1770035416);d = ff(d, a, b, c, x[i + 9], 12, -1958414417);c = ff(c, d, a, b, x[i + 10], 17, -42063);b = ff(b, c, d, a, x[i + 11], 22, -1990404162);a = ff(a, b, c, d, x[i + 12], 7, 1804603682);d = ff(d, a, b, c, x[i + 13], 12, -40341101);c = ff(c, d, a, b, x[i + 14], 17, -1502002290);b = ff(b, c, d, a, x[i + 15], 22, 1236535329);a = gg(a, b, c, d, x[i + 1], 5, -165796510);d = gg(d, a, b, c, x[i + 6], 9, -1069501632);c = gg(c, d, a, b, x[i + 11], 14, 643717713);b = gg(b, c, d, a, x[i + 0], 20, -373897302);a = gg(a, b, c, d, x[i + 5], 5, -701558691);d = gg(d, a, b, c, x[i + 10], 9, 38016083);c = gg(c, d, a, b, x[i + 15], 14, -660478335);b = gg(b, c, d, a, x[i + 4], 20, -405537848);a = gg(a, b, c, d, x[i + 9], 5, 568446438);d = gg(d, a, b, c, x[i + 14], 9, -1019803690);c = gg(c, d, a, b, x[i + 3], 14, -187363961);b = gg(b, c, d, a, x[i + 8], 20, 1163531501);a = gg(a, b, c, d, x[i + 13], 5, -1444681467);d = gg(d, a, b, c, x[i + 2], 9, -51403784);c = gg(c, d, a, b, x[i + 7], 14, 1735328473);b = gg(b, c, d, a, x[i + 12], 20, -1926607734);a = hh(a, b, c, d, x[i + 5], 4, -378558);d = hh(d, a, b, c, x[i + 8], 11, -2022574463);c = hh(c, d, a, b, x[i + 11], 16, 1839030562);b = hh(b, c, d, a, x[i + 14], 23, -35309556);a = hh(a, b, c, d, x[i + 1], 4, -1530992060);d = hh(d, a, b, c, x[i + 4], 11, 1272893353);c = hh(c, d, a, b, x[i + 7], 16, -155497632);b = hh(b, c, d, a, x[i + 10], 23, -1094730640);a = hh(a, b, c, d, x[i + 13], 4, 681279174);d = hh(d, a, b, c, x[i + 0], 11, -358537222);c = hh(c, d, a, b, x[i + 3], 16, -722521979);b = hh(b, c, d, a, x[i + 6], 23, 76029189);a = hh(a, b, c, d, x[i + 9], 4, -640364487);d = hh(d, a, b, c, x[i + 12], 11, -421815835);c = hh(c, d, a, b, x[i + 15], 16, 530742520);b = hh(b, c, d, a, x[i + 2], 23, -995338651);a = ii(a, b, c, d, x[i + 0], 6, -198630844);d = ii(d, a, b, c, x[i + 7], 10, 1126891415);c = ii(c, d, a, b, x[i + 14], 15, -1416354905);b = ii(b, c, d, a, x[i + 5], 21, -57434055);a = ii(a, b, c, d, x[i + 12], 6, 1700485571);d = ii(d, a, b, c, x[i + 3], 10, -1894986606);c = ii(c, d, a, b, x[i + 10], 15, -1051523);b = ii(b, c, d, a, x[i + 1], 21, -2054922799);a = ii(a, b, c, d, x[i + 8], 6, 1873313359);d = ii(d, a, b, c, x[i + 15], 10, -30611744);c = ii(c, d, a, b, x[i + 6], 15, -1560198380);b = ii(b, c, d, a, x[i + 13], 21, 1309151649);a = ii(a, b, c, d, x[i + 4], 6, -145523070);d = ii(d, a, b, c, x[i + 11], 10, -1120210379);c = ii(c, d, a, b, x[i + 2], 15, 718787259);b = ii(b, c, d, a, x[i + 9], 21, -343485551);a = add(a, olda);b = add(b, oldb);c = add(c, oldc);d = add(d, oldd);}return rhex(a) + rhex(b) + rhex(c) + rhex(d);}

-------------------------後台----------------------------------

拿到隨機字串：

String md5RandomKey = (String)request.getSession().getAttribute("md5RandomKey");

拿到密碼（MD5字串）：

String md5Password = request.getParameter("user_password");

然後通過使用者名稱到資料庫查詢該使用者的密碼，如果使用者不存在則提前提示錯誤。

拿到資料庫的密碼後和上面的隨機字串（md5RandomKey）一起產生MD5字串:

String md5Password_real = StringUtils.getMD5Str(attendant.getPassword()+md5RandomKey,null);

最後拿 md5Password_real和md5Password 進行比較，一致則通過驗證。

下面是上面代碼用到的在StringUtils下的兩個函數：

1：擷取隨機字串：

 private static final String ALLCHAR = "0123456789abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ";      /**     * 擷取任意位的隨機字串(0-9 a-z A-Z)     * @param size 位元     * @return     */    public static final String getRandomNum(int size){StringBuffer sb = new StringBuffer();  Random random = new Random();for (int i = 0; i < size; i++) {  sb.append(ALLCHAR.charAt(random.nextInt(ALLCHAR.length())));  }return sb.toString();    }

2：產生MD5字串：

        /**     * md5加密(ITS)     * @param str     * @param charSet     * @return     */    public synchronized static final String getMD5Str(String str,String charSet) { //md5加密MessageDigest messageDigest = null;  try {  messageDigest = MessageDigest.getInstance("MD5");  messageDigest.reset(); if(charSet==null){messageDigest.update(str.getBytes());}else{messageDigest.update(str.getBytes(charSet));  }} catch (NoSuchAlgorithmException e) {  log.error("md5 error:"+e.getMessage(),e);} catch (UnsupportedEncodingException e) {  log.error("md5 error:"+e.getMessage(),e);}  byte[] byteArray = messageDigest.digest();  StringBuffer md5StrBuff = new StringBuffer();  for (int i = 0; i < byteArray.length; i++) {              if (Integer.toHexString(0xFF & byteArray[i]).length() == 1)  md5StrBuff.append("0").append(Integer.toHexString(0xFF & byteArray[i]));  else  md5StrBuff.append(Integer.toHexString(0xFF & byteArray[i]));  }  return md5StrBuff.toString();  }

上面的 MessageDigest所在的包是：  java.security.MessageDigest