客户说我的***系统登录时密码是明文传输,不高兴,我对HTTPS不太了解,那我用MD5加密下,虽然不能保证万无一失,但也好过明文传输嘛。
说下大概的过程:打开登录的JSP页面时,生成一个随机字符串,放在session里面,以便后台也可以拿到。客户输入用户名和密码点击"登录"时,拿到密码和随机字符串,拼接在一起后利用js生成MD5字符串。然后用js把那个password的value改成MD5字符串,再提交表单。
后台拿到随机字符串和用户名和MD5字符串,通过用户名到数据库查询密码,用密码和随机字符串拼接在一起生成MD5字符串,用生成的MD5字符串和前台传过来的MD5字符串进行匹配,如果一致就通过验证。
------------------------------前台-------------------------------------
jsp页面生成随机数:
<% String pageName = pageContext.getRequest().getParameter("pageName"); pageName = StringUtils.filterUnsafeChars(pageName); //产生随机数,和密码一起生成MD5 request.getSession().setAttribute("md5RandomKey", StringUtils.getRandomNum(10)); %>
表单submit时调用下面的函数:
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); }
-------------------------后台----------------------------------
拿到随机字符串:
String md5RandomKey = (String)request.getSession().getAttribute("md5RandomKey");
拿到密码(MD5字符串):
String md5Password = request.getParameter("user_password");然后通过用户名到数据库查询该用户的密码,如果用户不存在则提前提示错误。
拿到数据库的密码后和上面的随机字符串(md5RandomKey)一起生成MD5字符串:
String md5Password_real = StringUtils.getMD5Str(attendant.getPassword()+md5RandomKey,null);
最后拿 md5Password_real和md5Password 进行比较,一致则通过验证。
下面是上面代码用到的在StringUtils下的两个函数:
1:获取随机字符串:
private static final String ALLCHAR = "0123456789abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ"; /** * 获取任意位的随机字符串(0-9 a-z A-Z) * @param size 位数 * @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