高校教务系统密码加密逻辑及JS逆向
本文将介绍高校教务系统的密码加密逻辑以及使用JavaScript进行逆向分析的过程。通过本文，你将了解到密码加密的基本概念、常用加密算法以及如何通过逆向分析来破解密码。
本文仅供交流学习，勿用于非法用途。
一、密码加密基本概念
密码加密是一种保护信息安全的技术手段，它通过将明文（原始信息）转换为密文（加密后的信息），以防止未经授权的访问和篡改。常见的密码加密算法有MD5、SHA-1、SHA-256等。
1.1 加密过程
加密过程通常包括以下步骤：
- 密钥扩展：将密钥扩展为多个轮值，每个轮值都与明文的一部分有关。
- 初始轮值生成：将扩展后的密钥与轮常数进行某种运算，生成第一轮加密的密文。
- 多轮迭代：对密文进行多轮迭代操作，每轮操作都包括非线性函数、模运算和轮常数的变换。
- 最终密文：经过多轮迭代后，得到最终的密文。
1.2 解密过程
解密过程与加密过程相反，通过反向操作来恢复原始明文。通常需要知道加密时使用的密钥和算法。
二、高校教务系统密码加密逻辑分析
2.1 抓包
我们首先打开教务系统的登录页面，我们可以看到，只有学号和密码，有的高校会有验证码，或者有的高校是错误一次密码，会验证验证码。
我们打开开发者工具，尝试登录抓包，网页会返回这样的数据接口。我们用户名和密码都是默认输入1234，你也可以输入其他的。
2.2 分析加密参数
我们接下来，就是来分析这个密码是怎么加密的。我们全局搜索rsa。定位到加密的位置。我们这里只有这个参数被加密了。我们猜想密码相关信息都包含在这个里面。
我们可以看到这里，定义了rsa是怎么生成的，是把u+p+lt拼接了在一起，这个还是第一次遇到。
三、JS逆向分析方法
逆向分析是指从已知的加密文本或程序中还原出原始信息的过程。在本例中，我们将使用JavaScript编写一个简单的逆向分析工具，用于逆向高校教务系统的密码。
环境使用
- python 3.9
- pycharm
- node
我们全局搜索strEnc，我们就很容易定位到一个函数，我们不难发现其加密原理。
function strEnc(data,firstKey,secondKey,thirdKey){
var leng = data.length;
var encData = "";
var firstKeyBt,secondKeyBt,thirdKeyBt,firstLength,secondLength,thirdLength;
if(firstKey != null && firstKey != ""){
firstKeyBt = getKeyBytes(firstKey);
firstLength = firstKeyBt.length;
}
if(secondKey != null && secondKey != ""){
secondKeyBt = getKeyBytes(secondKey);
secondLength = secondKeyBt.length;
}
if(thirdKey != null && thirdKey != ""){
thirdKeyBt = getKeyBytes(thirdKey);
thirdLength = thirdKeyBt.length;
}
- 首先，函数会接受两个参数：数据字符串
data和密钥key。- 然后，通过
CryptoJS.enc.Utf8.parse(key)将密钥从普通的字符串转换为CryptoJS可以处理的二进制格式。- 接着，使用
CryptoJS.AES.encrypt(data, key, {mode: CryptoJS.mode.ECB, padding: CryptoJS.pad.Pkcs7})对数据进行加密。这里使用了ECB模式和PKCS7填充方式。- 最后，通过调用
.toString()将加密后的数据对象转换为字符串形式并返回。
代码实现
/**
* DES加密解密
* @Copyright Copyright (c) 2006
* @author Guapo
* @see DESCore
*/
/*
* encrypt the string to string made up of hex
* return the encrypted string
*/
function strEnc(data,firstKey,secondKey,thirdKey){
var leng = data.length;
var encData = "";
var firstKeyBt,secondKeyBt,thirdKeyBt,firstLength,secondLength,thirdLength;
if(firstKey != null && firstKey != ""){
firstKeyBt = getKeyBytes(firstKey);
firstLength = firstKeyBt.length;
}
if(secondKey != null && secondKey != ""){
secondKeyBt = getKeyBytes(secondKey);
secondLength = secondKeyBt.length;
}
if(thirdKey != null && thirdKey != ""){
thirdKeyBt = getKeyBytes(thirdKey);
thirdLength = thirdKeyBt.length;
}
if(leng > 0){
if(leng < 4){
var bt = strToBt(data);
var encByte ;
if(firstKey != null && firstKey !="" && secondKey != null && secondKey != "" && thirdKey != null && thirdKey != ""){
var tempBt;
var x,y,z;
tempBt = bt;
for(x = 0;x < firstLength ;x ++){
tempBt = enc(tempBt,firstKeyBt[x]);
}
for(y = 0;y < secondLength ;y ++){
tempBt = enc(tempBt,secondKeyBt[y]);
}
for(z = 0;z < thirdLength ;z ++){
tempBt = enc(tempBt,thirdKeyBt[z]);
}
encByte = tempBt;
}else{
if(firstKey != null && firstKey !="" && secondKey != null && secondKey != ""){
var tempBt;
var x,y;
tempBt = bt;
for(x = 0;x < firstLength ;x ++){
tempBt = enc(tempBt,firstKeyBt[x]);
}
for(y = 0;y < secondLength ;y ++){
tempBt = enc(tempBt,secondKeyBt[y]);
}
encByte = tempBt;
}else{
if(firstKey != null && firstKey !=""){
var tempBt;
var x = 0;
tempBt = bt;
for(x = 0;x < firstLength ;x ++){
tempBt = enc(tempBt,firstKeyBt[x]);
}
encByte = tempBt;
}
}
}
encData = bt64ToHex(encByte);
}else{
var iterator = parseInt(leng/4);
var remainder = leng%4;
var i=0;
for(i = 0;i < iterator;i++){
var tempData = data.substring(i*4+0,i*4+4);
var tempByte = strToBt(tempData);
var encByte ;
if(firstKey != null && firstKey !="" && secondKey != null && secondKey != "" && thirdKey != null && thirdKey != ""){
var tempBt;
var x,y,z;
tempBt = tempByte;
for(x = 0;x < firstLength ;x ++){
tempBt = enc(tempBt,firstKeyBt[x]);
}
for(y = 0;y < secondLength ;y ++){
tempBt = enc(tempBt,secondKeyBt[y]);
}
for(z = 0;z < thirdLength ;z ++){
tempBt = enc(tempBt,thirdKeyBt[z]);
}
encByte = tempBt;
}else{
if(firstKey != null && firstKey !="" && secondKey != null && secondKey != ""){
var tempBt;
var x,y;
tempBt = tempByte;
for(x = 0;x < firstLength ;x ++){
tempBt = enc(tempBt,firstKeyBt[x]);
}
for(y = 0;y < secondLength ;y ++){
tempBt = enc(tempBt,secondKeyBt[y]);
}
encByte = tempBt;
}else{
if(firstKey != null && firstKey !=""){
var tempBt;
var x;
tempBt = tempByte;
for(x = 0;x < firstLength ;x ++){
tempBt = enc(tempBt,firstKeyBt[x]);
}
encByte = tempBt;
}
}
}
encData += bt64ToHex(encByte);
}
if(remainder > 0){
var remainderData = data.substring(iterator*4+0,leng);
var tempByte = strToBt(remainderData);
var encByte ;
if(firstKey != null && firstKey !="" && secondKey != null && secondKey != "" && thirdKey != null && thirdKey != ""){
var tempBt;
var x,y,z;
tempBt = tempByte;
for(x = 0;x < firstLength ;x ++){
tempBt = enc(tempBt,firstKeyBt[x]);
}
for(y = 0;y < secondLength ;y ++){
tempBt = enc(tempBt,secondKeyBt[y]);
}
for(z = 0;z < thirdLength ;z ++){
tempBt = enc(tempBt,thirdKeyBt[z]);
}
encByte = tempBt;
}else{
if(firstKey != null && firstKey !="" && secondKey != null && secondKey != ""){
var tempBt;
var x,y;
tempBt = tempByte;
for(x = 0;x < firstLength ;x ++){
tempBt = enc(tempBt,firstKeyBt[x]);
}
for(y = 0;y < secondLength ;y ++){
tempBt = enc(tempBt,secondKeyBt[y]);
}
encByte = tempBt;
}else{
if(firstKey != null && firstKey !=""){
var tempBt;
var x;
tempBt = tempByte;
for(x = 0;x < firstLength ;x ++){
tempBt = enc(tempBt,firstKeyBt[x]);
}
encByte = tempBt;
}
}
}
encData += bt64ToHex(encByte);
}
}
}
return encData;
}
/*
* decrypt the encrypted string to the original string
*
* return the original string
*/
function strDec(data,firstKey,secondKey,thirdKey){
var leng = data.length;
var decStr = "";
var firstKeyBt,secondKeyBt,thirdKeyBt,firstLength,secondLength,thirdLength;
if(firstKey != null && firstKey != ""){
firstKeyBt = getKeyBytes(firstKey);
firstLength = firstKeyBt.length;
}
if(secondKey != null && secondKey != ""){
secondKeyBt = getKeyBytes(secondKey);
secondLength = secondKeyBt.length;
}
if(thirdKey != null && thirdKey != ""){
thirdKeyBt = getKeyBytes(thirdKey);
thirdLength = thirdKeyBt.length;
}
var iterator = parseInt(leng/16);
var i=0;
for(i = 0;i < iterator;i++){
var tempData = data.substring(i*16+0,i*16+16);
var strByte = hexToBt64(tempData);
var intByte = new Array(64);
var j = 0;
for(j = 0;j < 64; j++){
intByte[j] = parseInt(strByte.substring(j,j+1));
}
var decByte;
if(firstKey != null && firstKey !="" && secondKey != null && secondKey != "" && thirdKey != null && thirdKey != ""){
var tempBt;
var x,y,z;
tempBt = intByte;
for(x = thirdLength - 1;x >= 0;x --){
tempBt = dec(tempBt,thirdKeyBt[x]);
}
for(y = secondLength - 1;y >= 0;y --){
tempBt = dec(tempBt,secondKeyBt[y]);
}
for(z = firstLength - 1;z >= 0 ;z --){
tempBt = dec(tempBt,firstKeyBt[z]);
}
decByte = tempBt;
}else{
if(firstKey != null && firstKey !="" && secondKey != null && secondKey != ""){
var tempBt;
var x,y,z;
tempBt = intByte;
for(x = secondLength - 1;x >= 0 ;x --){
tempBt = dec(tempBt,secondKeyBt[x]);
}
for(y = firstLength - 1;y >= 0 ;y --){
tempBt = dec(tempBt,firstKeyBt[y]);
}
decByte = tempBt;
}else{
if(firstKey != null && firstKey !=""){
var tempBt;
var x,y,z;
tempBt = intByte;
for(x = firstLength - 1;x >= 0 ;x --){
tempBt = dec(tempBt,firstKeyBt[x]);
}
decByte = tempBt;
}
}
}
decStr += byteToString(decByte);
}
return decStr;
}
/*
* chang the string into the bit array
*
* return bit array(it's length % 64 = 0)
*/
function getKeyBytes(key){
var keyBytes = new Array();
var leng = key.length;
var iterator = parseInt(leng/4);
var remainder = leng%4;
var i = 0;
for(i = 0;i < iterator; i ++){
keyBytes[i] = strToBt(key.substring(i*4+0,i*4+4));
}
if(remainder > 0){
keyBytes[i] = strToBt(key.substring(i*4+0,leng));
}
return keyBytes;
}
/*
* chang the string(it's length <= 4) into the bit array
*
* return bit array(it's length = 64)
*/
function strToBt(str){
var leng = str.length;
var bt = new Array(64);
if(leng < 4){
var i=0,j=0,p=0,q=0;
for(i = 0;i<leng;i++){
var k = str.charCodeAt(i);
for(j=0;j<16;j++){
var pow=1,m=0;
for(m=15;m>j;m--){
pow *= 2;
}
bt[16*i+j]=parseInt(k/pow)%2;
}
}
for(p = leng;p<4;p++){
var k = 0;
for(q=0;q<16;q++){
var pow=1,m=0;
for(m=15;m>q;m--){
pow *= 2;
}
bt[16*p+q]=parseInt(k/pow)%2;
}
}
}else{
for(i = 0;i<4;i++){
var k = str.charCodeAt(i);
for(j=0;j<16;j++){
var pow=1;
for(m=15;m>j;m--){
pow *= 2;
}
bt[16*i+j]=parseInt(k/pow)%2;
}
}
}
return bt;
}
/*
* chang the bit(it's length = 4) into the hex
*
* return hex
*/
function bt4ToHex(binary) {
var hex;
switch (binary) {
case "0000" : hex = "0"; break;
case "0001" : hex = "1"; break;
case "0010" : hex = "2"; break;
case "0011" : hex = "3"; break;
case "0100" : hex = "4"; break;
case "0101" : hex = "5"; break;
case "0110" : hex = "6"; break;
case "0111" : hex = "7"; break;
case "1000" : hex = "8"; break;
case "1001" : hex = "9"; break;
case "1010" : hex = "A"; break;
case "1011" : hex = "B"; break;
case "1100" : hex = "C"; break;
case "1101" : hex = "D"; break;
case "1110" : hex = "E"; break;
case "1111" : hex = "F"; break;
}
return hex;
}
/*
* chang the hex into the bit(it's length = 4)
*
* return the bit(it's length = 4)
*/
function hexToBt4(hex) {
var binary;
switch (hex) {
case "0" : binary = "0000"; break;
case "1" : binary = "0001"; break;
case "2" : binary = "0010"; break;
case "3" : binary = "0011"; break;
case "4" : binary = "0100"; break;
case "5" : binary = "0101"; break;
case "6" : binary = "0110"; break;
case "7" : binary = "0111"; break;
case "8" : binary = "1000"; break;
case "9" : binary = "1001"; break;
case "A" : binary = "1010"; break;
case "B" : binary = "1011"; break;
case "C" : binary = "1100"; break;
case "D" : binary = "1101"; break;
case "E" : binary = "1110"; break;
case "F" : binary = "1111"; break;
}
return binary;
}
/*
* chang the bit(it's length = 64) into the string
*
* return string
*/
function byteToString(byteData){
var str="";
for(i = 0;i<4;i++){
var count=0;
for(j=0;j<16;j++){
var pow=1;
for(m=15;m>j;m--){
pow*=2;
}
count+=byteData[16*i+j]*pow;
}
if(count != 0){
str+=String.fromCharCode(count);
}
}
return str;
}
function bt64ToHex(byteData){
var hex = "";
for(i = 0;i<16;i++){
var bt = "";
for(j=0;j<4;j++){
bt += byteData[i*4+j];
}
hex+=bt4ToHex(bt);
}
return hex;
}
function hexToBt64(hex){
var binary = "";
for(i = 0;i<16;i++){
binary+=hexToBt4(hex.substring(i,i+1));
}
return binary;
}
/*
* the 64 bit des core arithmetic
*/
function enc(dataByte,keyByte){
var keys = generateKeys(keyByte);
var ipByte = initPermute(dataByte);
var ipLeft = new Array(32);
var ipRight = new Array(32);
var tempLeft = new Array(32);
var i = 0,j = 0,k = 0,m = 0, n = 0;
for(k = 0;k < 32;k ++){
ipLeft[k] = ipByte[k];
ipRight[k] = ipByte[32+k];
}
for(i = 0;i < 16;i ++){
for(j = 0;j < 32;j ++){
tempLeft[j] = ipLeft[j];
ipLeft[j] = ipRight[j];
}
var key = new Array(48);
for(m = 0;m < 48;m ++){
key[m] = keys[i][m];
}
var tempRight = xor(pPermute(sBoxPermute(xor(expandPermute(ipRight),key))), tempLeft);
for(n = 0;n < 32;n ++){
ipRight[n] = tempRight[n];
}
}
var finalData =new Array(64);
for(i = 0;i < 32;i ++){
finalData[i] = ipRight[i];
finalData[32+i] = ipLeft[i];
}
return finallyPermute(finalData);
}
function dec(dataByte,keyByte){
var keys = generateKeys(keyByte);
var ipByte = initPermute(dataByte);
var ipLeft = new Array(32);
var ipRight = new Array(32);
var tempLeft = new Array(32);
var i = 0,j = 0,k = 0,m = 0, n = 0;
for(k = 0;k < 32;k ++){
ipLeft[k] = ipByte[k];
ipRight[k] = ipByte[32+k];
}
for(i = 15;i >= 0;i --){
for(j = 0;j < 32;j ++){
tempLeft[j] = ipLeft[j];
ipLeft[j] = ipRight[j];
}
var key = new Array(48);
for(m = 0;m < 48;m ++){
key[m] = keys[i][m];
}
var tempRight = xor(pPermute(sBoxPermute(xor(expandPermute(ipRight),key))), tempLeft);
for(n = 0;n < 32;n ++){
ipRight[n] = tempRight[n];
}
}
var finalData =new Array(64);
for(i = 0;i < 32;i ++){
finalData[i] = ipRight[i];
finalData[32+i] = ipLeft[i];
}
return finallyPermute(finalData);
}
function initPermute(originalData){
var ipByte = new Array(64);
for (i = 0, m = 1, n = 0; i < 4; i++, m += 2, n += 2) {
for (j = 7, k = 0; j >= 0; j--, k++) {
ipByte[i * 8 + k] = originalData[j * 8 + m];
ipByte[i * 8 + k + 32] = originalData[j * 8 + n];
}
}
return ipByte;
}
function expandPermute(rightData){
var epByte = new Array(48);
for (i = 0; i < 8; i++) {
if (i == 0) {
epByte[i * 6 + 0] = rightData[31];
} else {
epByte[i * 6 + 0] = rightData[i * 4 - 1];
}
epByte[i * 6 + 1] = rightData[i * 4 + 0];
epByte[i * 6 + 2] = rightData[i * 4 + 1];
epByte[i * 6 + 3] = rightData[i * 4 + 2];
epByte[i * 6 + 4] = rightData[i * 4 + 3];
if (i == 7) {
epByte[i * 6 + 5] = rightData[0];
} else {
epByte[i * 6 + 5] = rightData[i * 4 + 4];
}
}
return epByte;
}
function xor(byteOne,byteTwo){
var xorByte = new Array(byteOne.length);
for(i = 0;i < byteOne.length; i ++){
xorByte[i] = byteOne[i] ^ byteTwo[i];
}
return xorByte;
}
function sBoxPermute(expandByte){
var sBoxByte = new Array(32);
var binary = "";
var s1 = [
[14, 4, 13, 1, 2, 15, 11, 8, 3, 10, 6, 12, 5, 9, 0, 7],
[0, 15, 7, 4, 14, 2, 13, 1, 10, 6, 12, 11, 9, 5, 3, 8],
[4, 1, 14, 8, 13, 6, 2, 11, 15, 12, 9, 7, 3, 10, 5, 0],
[15, 12, 8, 2, 4, 9, 1, 7, 5, 11, 3, 14, 10, 0, 6, 13 ]];
/* Table - s2 */
var s2 = [
[15, 1, 8, 14, 6, 11, 3, 4, 9, 7, 2, 13, 12, 0, 5, 10],
[3, 13, 4, 7, 15, 2, 8, 14, 12, 0, 1, 10, 6, 9, 11, 5],
[0, 14, 7, 11, 10, 4, 13, 1, 5, 8, 12, 6, 9, 3, 2, 15],
[13, 8, 10, 1, 3, 15, 4, 2, 11, 6, 7, 12, 0, 5, 14, 9 ]];
/* Table - s3 */
var s3= [
[10, 0, 9, 14, 6, 3, 15, 5, 1, 13, 12, 7, 11, 4, 2, 8],
[13, 7, 0, 9, 3, 4, 6, 10, 2, 8, 5, 14, 12, 11, 15, 1],
[13, 6, 4, 9, 8, 15, 3, 0, 11, 1, 2, 12, 5, 10, 14, 7],
[1, 10, 13, 0, 6, 9, 8, 7, 4, 15, 14, 3, 11, 5, 2, 12 ]];
/* Table - s4 */
var s4 = [
[7, 13, 14, 3, 0, 6, 9, 10, 1, 2, 8, 5, 11, 12, 4, 15],
[13, 8, 11, 5, 6, 15, 0, 3, 4, 7, 2, 12, 1, 10, 14, 9],
[10, 6, 9, 0, 12, 11, 7, 13, 15, 1, 3, 14, 5, 2, 8, 4],
[3, 15, 0, 6, 10, 1, 13, 8, 9, 4, 5, 11, 12, 7, 2, 14 ]];
/* Table - s5 */
var s5 = [
[2, 12, 4, 1, 7, 10, 11, 6, 8, 5, 3, 15, 13, 0, 14, 9],
[14, 11, 2, 12, 4, 7, 13, 1, 5, 0, 15, 10, 3, 9, 8, 6],
[4, 2, 1, 11, 10, 13, 7, 8, 15, 9, 12, 5, 6, 3, 0, 14],
[11, 8, 12, 7, 1, 14, 2, 13, 6, 15, 0, 9, 10, 4, 5, 3 ]];
/* Table - s6 */
var s6 = [
[12, 1, 10, 15, 9, 2, 6, 8, 0, 13, 3, 4, 14, 7, 5, 11],
[10, 15, 4, 2, 7, 12, 9, 5, 6, 1, 13, 14, 0, 11, 3, 8],
[9, 14, 15, 5, 2, 8, 12, 3, 7, 0, 4, 10, 1, 13, 11, 6],
[4, 3, 2, 12, 9, 5, 15, 10, 11, 14, 1, 7, 6, 0, 8, 13 ]];
/* Table - s7 */
var s7 = [
[4, 11, 2, 14, 15, 0, 8, 13, 3, 12, 9, 7, 5, 10, 6, 1],
[13, 0, 11, 7, 4, 9, 1, 10, 14, 3, 5, 12, 2, 15, 8, 6],
[1, 4, 11, 13, 12, 3, 7, 14, 10, 15, 6, 8, 0, 5, 9, 2],
[6, 11, 13, 8, 1, 4, 10, 7, 9, 5, 0, 15, 14, 2, 3, 12]];
/* Table - s8 */
var s8 = [
[13, 2, 8, 4, 6, 15, 11, 1, 10, 9, 3, 14, 5, 0, 12, 7],
[1, 15, 13, 8, 10, 3, 7, 4, 12, 5, 6, 11, 0, 14, 9, 2],
[7, 11, 4, 1, 9, 12, 14, 2, 0, 6, 10, 13, 15, 3, 5, 8],
[2, 1, 14, 7, 4, 10, 8, 13, 15, 12, 9, 0, 3, 5, 6, 11]];
for(m=0;m<8;m++){
var i=0,j=0;
i = expandByte[m*6+0]*2+expandByte[m*6+5];
j = expandByte[m * 6 + 1] * 2 * 2 * 2
+ expandByte[m * 6 + 2] * 2* 2
+ expandByte[m * 6 + 3] * 2
+ expandByte[m * 6 + 4];
switch (m) {
case 0 :
binary = getBoxBinary(s1[i][j]);
break;
case 1 :
binary = getBoxBinary(s2[i][j]);
break;
case 2 :
binary = getBoxBinary(s3[i][j]);
break;
case 3 :
binary = getBoxBinary(s4[i][j]);
break;
case 4 :
binary = getBoxBinary(s5[i][j]);
break;
case 5 :
binary = getBoxBinary(s6[i][j]);
break;
case 6 :
binary = getBoxBinary(s7[i][j]);
break;
case 7 :
binary = getBoxBinary(s8[i][j]);
break;
}
sBoxByte[m*4+0] = parseInt(binary.substring(0,1));
sBoxByte[m*4+1] = parseInt(binary.substring(1,2));
sBoxByte[m*4+2] = parseInt(binary.substring(2,3));
sBoxByte[m*4+3] = parseInt(binary.substring(3,4));
}
return sBoxByte;
}
function pPermute(sBoxByte){
var pBoxPermute = new Array(32);
pBoxPermute[ 0] = sBoxByte[15];
pBoxPermute[ 1] = sBoxByte[ 6];
pBoxPermute[ 2] = sBoxByte[19];
pBoxPermute[ 3] = sBoxByte[20];
pBoxPermute[ 4] = sBoxByte[28];
pBoxPermute[ 5] = sBoxByte[11];
pBoxPermute[ 6] = sBoxByte[27];
pBoxPermute[ 7] = sBoxByte[16];
pBoxPermute[ 8] = sBoxByte[ 0];
pBoxPermute[ 9] = sBoxByte[14];
pBoxPermute[10] = sBoxByte[22];
pBoxPermute[11] = sBoxByte[25];
pBoxPermute[12] = sBoxByte[ 4];
pBoxPermute[13] = sBoxByte[17];
pBoxPermute[14] = sBoxByte[30];
pBoxPermute[15] = sBoxByte[ 9];
pBoxPermute[16] = sBoxByte[ 1];
pBoxPermute[17] = sBoxByte[ 7];
pBoxPermute[18] = sBoxByte[23];
pBoxPermute[19] = sBoxByte[13];
pBoxPermute[20] = sBoxByte[31];
pBoxPermute[21] = sBoxByte[26];
pBoxPermute[22] = sBoxByte[ 2];
pBoxPermute[23] = sBoxByte[ 8];
pBoxPermute[24] = sBoxByte[18];
pBoxPermute[25] = sBoxByte[12];
pBoxPermute[26] = sBoxByte[29];
pBoxPermute[27] = sBoxByte[ 5];
pBoxPermute[28] = sBoxByte[21];
pBoxPermute[29] = sBoxByte[10];
pBoxPermute[30] = sBoxByte[ 3];
pBoxPermute[31] = sBoxByte[24];
return pBoxPermute;
}
function finallyPermute(endByte){
var fpByte = new Array(64);
fpByte[ 0] = endByte[39];
fpByte[ 1] = endByte[ 7];
fpByte[ 2] = endByte[47];
fpByte[ 3] = endByte[15];
fpByte[ 4] = endByte[55];
fpByte[ 5] = endByte[23];
fpByte[ 6] = endByte[63];
fpByte[ 7] = endByte[31];
fpByte[ 8] = endByte[38];
fpByte[ 9] = endByte[ 6];
fpByte[10] = endByte[46];
fpByte[11] = endByte[14];
fpByte[12] = endByte[54];
fpByte[13] = endByte[22];
fpByte[14] = endByte[62];
fpByte[15] = endByte[30];
fpByte[16] = endByte[37];
fpByte[17] = endByte[ 5];
fpByte[18] = endByte[45];
fpByte[19] = endByte[13];
fpByte[20] = endByte[53];
fpByte[21] = endByte[21];
fpByte[22] = endByte[61];
fpByte[23] = endByte[29];
fpByte[24] = endByte[36];
fpByte[25] = endByte[ 4];
fpByte[26] = endByte[44];
fpByte[27] = endByte[12];
fpByte[28] = endByte[52];
fpByte[29] = endByte[20];
fpByte[30] = endByte[60];
fpByte[31] = endByte[28];
fpByte[32] = endByte[35];
fpByte[33] = endByte[ 3];
fpByte[34] = endByte[43];
fpByte[35] = endByte[11];
fpByte[36] = endByte[51];
fpByte[37] = endByte[19];
fpByte[38] = endByte[59];
fpByte[39] = endByte[27];
fpByte[40] = endByte[34];
fpByte[41] = endByte[ 2];
fpByte[42] = endByte[42];
fpByte[43] = endByte[10];
fpByte[44] = endByte[50];
fpByte[45] = endByte[18];
fpByte[46] = endByte[58];
fpByte[47] = endByte[26];
fpByte[48] = endByte[33];
fpByte[49] = endByte[ 1];
fpByte[50] = endByte[41];
fpByte[51] = endByte[ 9];
fpByte[52] = endByte[49];
fpByte[53] = endByte[17];
fpByte[54] = endByte[57];
fpByte[55] = endByte[25];
fpByte[56] = endByte[32];
fpByte[57] = endByte[ 0];
fpByte[58] = endByte[40];
fpByte[59] = endByte[ 8];
fpByte[60] = endByte[48];
fpByte[61] = endByte[16];
fpByte[62] = endByte[56];
fpByte[63] = endByte[24];
return fpByte;
}
function getBoxBinary(i) {
var binary = "";
switch (i) {
case 0 :binary = "0000";break;
case 1 :binary = "0001";break;
case 2 :binary = "0010";break;
case 3 :binary = "0011";break;
case 4 :binary = "0100";break;
case 5 :binary = "0101";break;
case 6 :binary = "0110";break;
case 7 :binary = "0111";break;
case 8 :binary = "1000";break;
case 9 :binary = "1001";break;
case 10 :binary = "1010";break;
case 11 :binary = "1011";break;
case 12 :binary = "1100";break;
case 13 :binary = "1101";break;
case 14 :binary = "1110";break;
case 15 :binary = "1111";break;
}
return binary;
}
/*
* generate 16 keys for xor
*
*/
function generateKeys(keyByte){
var key = new Array(56);
var keys = new Array();
keys[ 0] = new Array();
keys[ 1] = new Array();
keys[ 2] = new Array();
keys[ 3] = new Array();
keys[ 4] = new Array();
keys[ 5] = new Array();
keys[ 6] = new Array();
keys[ 7] = new Array();
keys[ 8] = new Array();
keys[ 9] = new Array();
keys[10] = new Array();
keys[11] = new Array();
keys[12] = new Array();
keys[13] = new Array();
keys[14] = new Array();
keys[15] = new Array();
var loop = [1,1,2,2,2,2,2,2,1,2,2,2,2,2,2,1];
for(i=0;i<7;i++){
for(j=0,k=7;j<8;j++,k--){
key[i*8+j]=keyByte[8*k+i];
}
}
var i = 0;
for(i = 0;i < 16;i ++){
var tempLeft=0;
var tempRight=0;
for(j = 0; j < loop[i];j ++){
tempLeft = key[0];
tempRight = key[28];
for(k = 0;k < 27 ;k ++){
key[k] = key[k+1];
key[28+k] = key[29+k];
}
key[27]=tempLeft;
key[55]=tempRight;
}
var tempKey = new Array(48);
tempKey[ 0] = key[13];
tempKey[ 1] = key[16];
tempKey[ 2] = key[10];
tempKey[ 3] = key[23];
tempKey[ 4] = key[ 0];
tempKey[ 5] = key[ 4];
tempKey[ 6] = key[ 2];
tempKey[ 7] = key[27];
tempKey[ 8] = key[14];
tempKey[ 9] = key[ 5];
tempKey[10] = key[20];
tempKey[11] = key[ 9];
tempKey[12] = key[22];
tempKey[13] = key[18];
tempKey[14] = key[11];
tempKey[15] = key[ 3];
tempKey[16] = key[25];
tempKey[17] = key[ 7];
tempKey[18] = key[15];
tempKey[19] = key[ 6];
tempKey[20] = key[26];
tempKey[21] = key[19];
tempKey[22] = key[12];
tempKey[23] = key[ 1];
tempKey[24] = key[40];
tempKey[25] = key[51];
tempKey[26] = key[30];
tempKey[27] = key[36];
tempKey[28] = key[46];
tempKey[29] = key[54];
tempKey[30] = key[29];
tempKey[31] = key[39];
tempKey[32] = key[50];
tempKey[33] = key[44];
tempKey[34] = key[32];
tempKey[35] = key[47];
tempKey[36] = key[43];
tempKey[37] = key[48];
tempKey[38] = key[38];
tempKey[39] = key[55];
tempKey[40] = key[33];
tempKey[41] = key[52];
tempKey[42] = key[45];
tempKey[43] = key[41];
tempKey[44] = key[49];
tempKey[45] = key[35];
tempKey[46] = key[28];
tempKey[47] = key[31];
switch(i){
case 0: for(m=0;m < 48 ;m++){ keys[ 0][m] = tempKey[m]; } break;
case 1: for(m=0;m < 48 ;m++){ keys[ 1][m] = tempKey[m]; } break;
case 2: for(m=0;m < 48 ;m++){ keys[ 2][m] = tempKey[m]; } break;
case 3: for(m=0;m < 48 ;m++){ keys[ 3][m] = tempKey[m]; } break;
case 4: for(m=0;m < 48 ;m++){ keys[ 4][m] = tempKey[m]; } break;
case 5: for(m=0;m < 48 ;m++){ keys[ 5][m] = tempKey[m]; } break;
case 6: for(m=0;m < 48 ;m++){ keys[ 6][m] = tempKey[m]; } break;
case 7: for(m=0;m < 48 ;m++){ keys[ 7][m] = tempKey[m]; } break;
case 8: for(m=0;m < 48 ;m++){ keys[ 8][m] = tempKey[m]; } break;
case 9: for(m=0;m < 48 ;m++){ keys[ 9][m] = tempKey[m]; } break;
case 10: for(m=0;m < 48 ;m++){ keys[10][m] = tempKey[m]; } break;
case 11: for(m=0;m < 48 ;m++){ keys[11][m] = tempKey[m]; } break;
case 12: for(m=0;m < 48 ;m++){ keys[12][m] = tempKey[m]; } break;
case 13: for(m=0;m < 48 ;m++){ keys[13][m] = tempKey[m]; } break;
case 14: for(m=0;m < 48 ;m++){ keys[14][m] = tempKey[m]; } break;
case 15: for(m=0;m < 48 ;m++){ keys[15][m] = tempKey[m]; } break;
}
}
return keys;
}
var u = '1234'
var p = '1234'
var lt = ' LT-318507-wymVTnxdHIivdYhDVasTwXTNEKnqTI-cas'
var rsa =strEnc(u+p+lt , '1' , '2' , '3')
console.log(rsa)我这里直接把代码给大家，大家感兴趣可以先尝试直接去写，可以和我写的做比较。
实现效果
C1BB5938DF9F2190C1BB5938DF9F21906C47B718205114E97CBA49C9BE760421885CBED73DBA20760A8CE596669EA996ECAE08DFB1001AFC0C53B6B482DC1A450D45FA2BFB9C2F07AEF9D3E23DE6C7061D6814B8F1D6CEBC279B336B204A11587914575B59A84A0FB2DA8880EA270330
我们可以发现，这个结果和网页的结果一样的，说明我们逆向成功了。
四、总结
本文介绍了高校教务系统的密码加密逻辑以及使用JavaScript进行逆向分析的方法。通过学习这些知识，你可以更好地理解密码加密技术的原理，并掌握一定的逆向分析技巧。请注意，逆向分析可能涉及到法律问题，请在合法范围内进行研究和实践。
五、累计更新
争取到到底早日更新30所高校，大家可以在评论区留言。前期更的可能会多一点，有的学校教务系统都没有加密，我这里就不写了，还有，部分学校的教务系统已经和我之前写的是一样的，我也不重复赘述了。
往期作品可以查看专栏👇👇👇
全国高校教务系统登录页面JS分析_爱吃饼干的小白鼠的博客-CSDN博客
