关于base64前端加密，后端解密

公司做的系统是给某公司内网的系统。做了一个渗透测试。提出一点漏洞，关于用户名和密码在传输中是用明文传输的，但后台接到后已经做了MD5加密进行校验而且还是内网，一般这个是没问题的。但提出了漏洞就改呗，加个密。思路是前端加密，后端解密。

前端 

<script src="<c:url value='/scripts/base64.js'/>"></script>

function submitForm(){
var abc=document.getElementById("submit");
abc.disabled=true;
var str1=document.getElementById('j_username').value.trim();
var str2=document.getElementById('j_password').value.trim();
var result = Base.encode(str1);
document.getElementById('j_username').value=result;
var res = Base.encode(str2);
document.getElementById('j_password').value=res;
loginForm.submit();
}

base64.js:

//base64加密 解密

/* //1.加密
var result = Base.encode('125中文');  //--> "MTI15Lit5paH"

//2.解密
var result2 = Base.decode(result); //--> '125中文'
*/

~(function(root, factory) {
if (typeof define === "function" && define.amd) {
define([], factory);
} else if (typeof module === "object" && module.exports) {
module.exports = factory();
} else {
root.Base = factory();
}
}(this, function() {
'use strict';

function Base64() {
// private property
this._keyStr = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/=";
}
//public method for encoding
Base64.prototype.encode = function (input) {
var output = "", chr1, chr2, chr3, enc1, enc2, enc3, enc4, i = 0;
input = this._utf8_encode(input);
while (i < input.length) {
chr1 = input.charCodeAt(i++);
chr2 = input.charCodeAt(i++);
chr3 = input.charCodeAt(i++);
enc1 = chr1 >> 2;
enc2 = ((chr1 & 3) << 4) | (chr2 >> 4);
enc3 = ((chr2 & 15) << 2) | (chr3 >> 6);
enc4 = chr3 & 63;
if (isNaN(chr2)) {
enc3 = enc4 = 64;
} else if (isNaN(chr3)) {
enc4 = 64;
}
output = output +
this._keyStr.charAt(enc1) + this._keyStr.charAt(enc2) +
this._keyStr.charAt(enc3) + this._keyStr.charAt(enc4);
}
return output;
}

// public method for decoding
Base64.prototype.decode = function (input) {
var output = "", chr1, chr2, chr3, enc1, enc2, enc3, enc4, i = 0;
input = input.replace(/[^A-Za-z0-9\+\/\=]/g, "");
while (i < input.length) {
enc1 = this._keyStr.indexOf(input.charAt(i++));
enc2 = this._keyStr.indexOf(input.charAt(i++));
enc3 = this._keyStr.indexOf(input.charAt(i++));
enc4 = this._keyStr.indexOf(input.charAt(i++));
chr1 = (enc1 << 2) | (enc2 >> 4);
chr2 = ((enc2 & 15) << 4) | (enc3 >> 2);
chr3 = ((enc3 & 3) << 6) | enc4;
output = output + String.fromCharCode(chr1);
if (enc3 != 64) {
output = output + String.fromCharCode(chr2);
}
if (enc4 != 64) {
output = output + String.fromCharCode(chr3);
}
}
output = this._utf8_decode(output);
return output;
}

// private method for UTF-8 encoding
Base64.prototype._utf8_encode = function (string) {
string = string.replace(/\r\n/g,"\n");
var utftext = "";
for (var n = 0; n < string.length; n++) {
var c = string.charCodeAt(n);
if (c < 128) {
utftext += String.fromCharCode(c);
} else if((c > 127) && (c < 2048)) {
utftext += String.fromCharCode((c >> 6) | 192);
utftext += String.fromCharCode((c & 63) | 128);
} else {
utftext += String.fromCharCode((c >> 12) | 224);
utftext += String.fromCharCode(((c >> 6) & 63) | 128);
utftext += String.fromCharCode((c & 63) | 128);
}

}
return utftext;
}

// private method for UTF-8 decoding
Base64.prototype._utf8_decode = function (utftext) {
var string = "", i = 0, c = 0, c1 = 0, c2 = 0, c3 = 0;
while ( i < utftext.length ) {
c = utftext.charCodeAt(i);
if (c < 128) {
string += String.fromCharCode(c);
i++;
} else if((c > 191) && (c < 224)) {
c2 = utftext.charCodeAt(i+1);
string += String.fromCharCode(((c & 31) << 6) | (c2 & 63));
i += 2;
} else {
c2 = utftext.charCodeAt(i+1);
c3 = utftext.charCodeAt(i+2);
string += String.fromCharCode(((c & 15) << 12) | ((c2 & 63) << 6) | (c3 & 63));
i += 3;
}
}
return string;
}

var Base = new Base64();

return Base;
}));

后端工具类：

package com.sasis.util;

import sun.misc.BASE64Decoder;
import sun.misc.BASE64Encoder;

public final class BASE64Util {

/**
* 采用BASE64算法对字符串进行加密
* @param base 原字符串
* @return 加密后的字符串
*/
public static final String encode(String base){
return BASE64Util.encode(base.getBytes());
}

/**
* 采用BASE64算法对字节数组进行加密
* @param baseBuff 原字节数组
* @return 加密后的字符串
*/
public static final String encode(byte[] baseBuff){
return new BASE64Encoder().encode(baseBuff);
}

/**
* 字符串解密，采用BASE64的算法
* @param encoder 需要解密的字符串
* @return 解密后的字符串
*/
public static final String decode(String encoder){
try {
BASE64Decoder decoder = new BASE64Decoder();
byte[] buf = decoder.decodeBuffer(encoder);
return new String(buf);
} catch (Exception e) {

return null;
}
}
}

后端处理：

String username1 = request.getParameter("j_username");
String password1 = request.getParameter("j_password");
log.info("用户名："+username1);
log.info("密码："+password1);
//后端解密
String username=BASE64Util.decode(username1);
String password=BASE64Util.decode(password1);
SimpleDateFormat sdf=new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");
String time=sdf.format(new Date());
log.info("操作时间："+time+"用户名："+username);