javascript+Java 實現MD5加密登陸密碼

客戶說個人***系統登陸時密碼是明文傳輸，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：打開登陸的JSP頁面時，生成一個隨機字符串，放在session裏面，以便後臺也能夠拿到。客戶輸入用戶名和密碼點擊"登陸"時，拿到密碼和隨機字符串，拼接在一塊兒後利用js生成MD5字符串。而後用js把那個password的value改爲MD5字符串，再提交表單。

後臺拿到隨機字符串和用戶名和MD5字符串，經過用戶名到數據庫查詢密碼，用密碼和隨機字符串拼接在一塊兒生成MD5字符串，用生成的MD5字符串和前臺傳過來的MD5字符串進行匹配，若是一致就經過驗證。

------------------------------前臺-------------------------------------

jsp頁面生成隨機數：

<%
String pageName = pageContext.getRequest().getParameter("pageName");
pageName = StringUtils.filterUnsafeChars(pageName); //業務系統內部的一個過濾操做，能夠跳過這一步
//產生隨機數，和密碼一塊兒生成MD5
request.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以下：

/*
 * 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);
}

-------------------------後臺----------------------------------

拿到隨機字符串：

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

拿到密碼（MD5字符串）：

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

而後經過用戶名到數據庫查詢該用戶的密碼，若是用戶不存在則提早提示錯誤。

拿到數據庫的密碼後和上面的隨機字符串（md5RandomKey）一塊兒生成MD5字符串:

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

最後拿 md5Password_real和md5Password 進行比較，一致則經過驗證。

下面是上面代碼用到的在StringUtils下的兩個函數：

1：獲取隨機字符串：

private static final String ALLCHAR = "0123456789abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ";  
    /**
     * 獲取任意位的隨機字符串(0-9 a-z A-Z)
     * @param size 位數
     * @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：生成MD5字符串：

/**
     * 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

附加參考：

http://my.oschina.net/bearfly1990/blog/50388

http://my.oschina.net/hao0610/blog/131397