微信小程序使用Base64加密解密

标签：case keyStr charAt 微信 Base64 解密 str var out

js文件：

var base64 = {
    _keyStr: "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/=",
    encode (str) { // 加密
      var output = "";
      var chr1, chr2, chr3, enc1, enc2, enc3, enc4;
      var i = 0;
      str = this._utf16to8(str);
      while (i < str.length) {
        chr1 = str.charCodeAt(i++);
        chr2 = str.charCodeAt(i++);
        chr3 = str.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;
    },
    decode (input) { // 解密
      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 = 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);
          }
      } return this._utf8to16(output);
    },
    _utf16to8: function(str) {
      var out, i, len, c;
      out = "";
      len = str.length;
      for(i = 0; i < len; i++) {
          c = str.charCodeAt(i);
          if ((c >= 0x0001) && (c <= 0x007F)) {
              out += str.charAt(i);
          } else if (c > 0x07FF) {
              out += String.fromCharCode(0xE0 | ((c >> 12) & 0x0F));
              out += String.fromCharCode(0x80 | ((c >> 6) & 0x3F));
              out += String.fromCharCode(0x80 | ((c >> 0) & 0x3F));
          } else {
              out += String.fromCharCode(0xC0 | ((c >> 6) & 0x1F));
              out += String.fromCharCode(0x80 | ((c >> 0) & 0x3F));
          }
      }
      return out;
    },
    _utf8to16 (str) { 
      var out, i, len, c;
      var char2, char3;
      out = "";
      len = str.length;
      i = 0;
      while(i < len) {
          c = str.charCodeAt(i++);
          switch(c >> 4)
          {
              case 0: case 1: case 2: case 3: case 4: case 5: case 6:case7:
                out += str.charAt(i-1);
              break;
              case 12: case 13:
                char2 = str.charCodeAt(i++);
                out += String.fromCharCode(((c & 0x1F) << 6) | (char2&0x3F));
              break;
              case 14:
                char2 = str.charCodeAt(i++);
                char3 = str.charCodeAt(i++);
                out += String.fromCharCode(((c & 0x0F) << 12) |
                  ((char2 & 0x3F) << 6) |
                  ((char3 & 0x3F) << 0));
              break;
          }
      } return out;
    }
  }
  
  /* 暴露函数 */
  module.exports = base64

　　使用方法

　　let base = require('../../utils/base.js')//导入上方的base64文件

let stamp = Math.round(new Date() / 1000) //时间戳
let secret = base.encode(stamp)//base64加密

　解密：

解密就没了，上面的解密代码不太准确，加密准确

标签：case,keyStr,charAt,微信,Base64,解密,str,var,out
From： https://www.cnblogs.com/wencaiguagua/p/17119094.html