// LoginPswd = 71a562ba53aa , seesion = whuwk4uvwt0tkcftktkresk5
var pwd = decrpt('71a562ba53aa','whuwk4uvwt0tkcftktkresk5');
console.log('pwd='+pwd);
//解密
function decrpt(encryptHexStr, keyStr){
var keyArr = string2Bytes(keyStr);
var c = string2Bytes(keyStr);
var b = -1;
var firstRandom = hex2int(encryptHexStr[0]+encryptHexStr[1]);//第一个随机数
var decrptPwd = [];
var hex = '';
for(var i = 2 ; i < encryptHexStr.length ; i+=2){
hex = encryptHexStr[i]+encryptHexStr[i+1] ;
var j = hex2int(hex);
console.log("input="+j);
if (b < keyStr.length - 1) {
b++
} else {
b = 0
}
var t = c[b]; //取出要异或的密钥
var o = j ^ t ; // 再异或出原来的数
if(o < firstRandom ){
o = o +255 ; // 由于原来是”((k) % 255)” ,所以简单的补上255 ,逻辑不严谨
}
var out = int2CharCode((o-firstRandom));//减去原来加的随机数，解密出来的字符
console.log('t='+t+",firstRandom="+firstRandom + ",correct="+ out );
firstRandom = j ; //下一个随机数
decrptPwd.push(out);
}
return decrptPwd.join("");
}
//int 转assi 码
function int2CharCode(i){
return String.fromCharCode(i);
}
//16进制字符串转int 类型数据
function hex2int(hex) {
var len = hex.length, a = new Array(len), code;
for (var i = 0; i < len; i++) {
code = hex.charCodeAt(i);
if (48<=code && code < 58) {
code -= 48;
} else {
code = (code & 0xdf) - 65 + 10;
}
a[i] = code;
}
return a.reduce(function(acc, c) {
acc = 16 * acc + c;
return acc;
}, 0);
}
// 字符串 转对应assi 码的数组
function string2Bytes ( str ) {
var ch, st, re = [];
for (var i = 0; i < str.length; i++ ) {
ch = str.charCodeAt(i); // get char
st = []; // set up "stack"
do {
st.push( ch & 0xFF ); // push byte to stack
ch = ch >> 8; // shift value down by 1 byte
}
while ( ch );
// add stack contents to result
// done because chars have "wrong" endianness
re = re.concat( st.reverse() );
}
// return an array of bytes
return re;
}
