前端請求參數MD5加密校驗,參數串解密

首先引入MD5加密庫：=>https://cdn.bootcss.com/blueimp-md5/2.10.0/js/md5.min.js;

　　步驟：=》1.請求前對參數進行字典升序排序，排序函數　

function objKeySort(obj) {

var newkey = Object.keys(obj).sort();

//先用Object內置類的keys方法獲取要排序對象的屬性名，再利用Array原型上的sort方法對獲取的屬性名進行排序，newkey是一個數組

var newObj = {};//建立一個新的對象，用於存放排好序的鍵值對

for (var i = 0; i < newkey.length; i++) {//遍歷newkey數組

newObj[newkey[i]] = obj[newkey[i]];//向新建立的對象中按照排好的順序依次增長鍵值對

}

return newObj;//返回排好序的新對象

}

　　　　　　2.排序後對參數進行校驗,校驗參數涉及簽名的請求頭=》

oncekey	客戶端生成臨時隨機數6-8位字母或數字
timestr	timestr時間戳
signkey	請求籤名key

wxsmall

對隨機生成的oncekeyMD5

　　　　　　並將oncekey 與timestr鏈接進行MD5，得到hash字符串 將hash與datastr鏈接進行md5，datastr需引用函數objtostring將其轉化爲字符串,獲得簽名signkey,校驗簽名函數+字符串轉化函數objtostring：　　　　

function signrequest
(data) {

data = objKeySort(data);//請求參數排序

var staticstr = '';

var timestr = parseInt((new Date()).getTime() / 1000);

var oncekey = parseInt(Math.random() * (100000 - 1000 + 1) + 1000, 10);

var wxsmall = md5(oncekey);

console.log("wxsmall：" + wxsmall);

var hash = md5(md5(wxsmall + '' + oncekey));

console.log("hash：" + hash);

var datastr = objtostring(data);

console.log("hash+datastr：" + hash + datastr);

var sign = md5(hash + datastr);

return { "timestr": timestr, "oncekey": oncekey, "wxsmall": wxsmall, "signkey": sign };

}

 

function objtostring(data) {//Object to String

var str = '';

for (var k in data) {

str += k + '=' + encodeURI(data[k]) + '&';

}

if (str) {

str = str.substring(str, str.length - 1);

}

return str;

}

3.數據解密規則:

• 對簽名經過後返回的data加密串signdata進行base64解碼，獲得Base64後的串,Base64解碼函數decode=>
• function  decode(input) {

  var output = "";

  var chr1, chr2, chr3;

  var enc1, enc2, enc3, enc4;

  var i = 0;

  input = input.replace(/[^A-Za-z0-9\+\/\=]/g, "");

  while (i < input.length) {

  enc1 = _keyStr.indexOf(input.charAt(i++));

  enc2 = _keyStr.indexOf(input.charAt(i++));

  enc3 = _keyStr.indexOf(input.charAt(i++));

  enc4 = _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 = _utf8_decode(output);

  return output;

  }

  // private method for UTF-8 decoding

  var _utf8_decode = function (utftext) {

  var string = "";

  var i = 0;

  var 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;

  }
• 截取BASE64串string長度-4後進行MD5，並對MD5後的字符串截取長度15的串，將該串與BASE64串string長度-4後的串進行異或運算獲得解密後的data字符串=>
• function responseencode(data, apiSignModel) {//data => encode string
  var isencode = 0;
  isencode = apiSignModel;
  
  
  if (!isencode) {
  return data;
  }
  console.log("---callback-----data---encode--->", data);
  data = base64.decode(data);//encodeString
  
  
  var rand = data.substring(data.length - 4);
  var md = md5(rand);
  var p = md.substring(0, 16);
  console.log("data " + data);
  console.log("rand " + rand);
  data = data.substring(0, data.length - 4);
  data = strox(data, p);
  console.log("p " + p);
  return data;
  }

 其中apiSignModel就是responseHeader返回的API-SIGN-MODAL,客戶端能夠根據該返回參數決定是否對返回的數據串 解密,異或運算是爲了獲得通過一次異或運算以前的初始加密串，字符串在通過兩次異或運算會獲得原始的數據，參考https://www.lijinma.com/blog/2014/05/29/amazing-xor/，異或勻速算實現函數=>

function strox(str, orstr) {

var result = [];

var len = orstr.length;

for (var i = 0; i < str.length; i++) {

var item = str[i];

var strcode = parseInt(item.charCodeAt().toString(10));

var orcode = parseInt(orstr[i % len].charCodeAt().toString(10));

var rescode = strcode ^ orcode;

var binaryStr = String.fromCharCode(rescode);

result.push(binaryStr);

}

return result.join("");

}

簡單來講，異或運算函數是將兩個參數1和2相加進行異或獲得3，再次異或運算後可將3和1進行異或就能夠得出異或前的數字2.總體代碼封裝一下就是這樣：

import md5 from './md5-support.js';

var Base64 = function () {

// private property

var _keyStr = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/=";

// public method for decoding

this.decode = function (input) {

var output = "";

var chr1, chr2, chr3;

var enc1, enc2, enc3, enc4;

var i = 0;

input = input.replace(/[^A-Za-z0-9\+\/\=]/g, "");

while (i < input.length) {

enc1 = _keyStr.indexOf(input.charAt(i++));

enc2 = _keyStr.indexOf(input.charAt(i++));

enc3 = _keyStr.indexOf(input.charAt(i++));

enc4 = _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 = _utf8_decode(output);

return output;

}

// private method for UTF-8 decoding

var _utf8_decode = function (utftext) {

var string = "";

var i = 0;

var 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 Apisecure = function () {

var base64 = new Base64();

function strox(str, orstr) {

var result = [];

var len = orstr.length;

for (var i = 0; i < str.length; i++) {

var item = str[i];

var strcode = parseInt(item.charCodeAt().toString(10));

var orcode = parseInt(orstr[i % len].charCodeAt().toString(10));

var rescode = strcode ^ orcode;

var binaryStr = String.fromCharCode(rescode);

result.push(binaryStr);

}

return result.join("");

}

function objtostring(data) {

var str = '';

for (var k in data) {

str += k + '=' + encodeURI(data[k]) + '&';

}

if (str) {

str = str.substring(str, str.length - 1);

}

return str;

}

function objKeySort(obj) {//排序的函數

var newkey = Object.keys(obj).sort();

//先用Object內置類的keys方法獲取要排序對象的屬性名，再利用Array原型上的sort方法對獲取的屬性名進行排序，newkey是一個數組

var newObj = {};//建立一個新的對象，用於存放排好序的鍵值對

for (var i = 0; i < newkey.length; i++) {//遍歷newkey數組

newObj[newkey[i]] = obj[newkey[i]];//向新建立的對象中按照排好的順序依次增長鍵值對

}

return newObj;//返回排好序的新對象

}

this.signrequest = function (data) {

data = objKeySort(data);//請求參數排序

var staticstr = '';

var timestr = parseInt((new Date()).getTime() / 1000);

var oncekey = parseInt(Math.random() * (100000 - 1000 + 1) + 1000, 10);

var wxsmall = md5(oncekey);

console.log("wxsmall：" + wxsmall);

var hash = md5(md5(wxsmall + '' + oncekey));

console.log("hash：" + hash);

var datastr = objtostring(data);

console.log("hash+datastr：" + hash + datastr);

var sign = md5(hash + datastr);

return { "timestr": timestr, "oncekey": oncekey, "wxsmall": wxsmall, "signkey": sign };

}

this.responseencode = function (data, apiSignModel) {//data => encode string

var isencode = 0;

isencode = apiSignModel;

if (!isencode) {

return data;

}

console.log("---callback-----data---encode--->", data);

data = base64.decode(data);//encodeString

var rand = data.substring(data.length - 4);

var md = md5(rand);

var p = md.substring(0, 16);

console.log("data " + data);

console.log("rand " + rand);

data = data.substring(0, data.length - 4);

data = strox(data, p);

console.log("p " + p);

return data;

}

}

module.exports = {

Base64,

Apisecure

}

最後附上小程序內封裝的微信請求調用方法=>