iVProg/js/util/base64.js

/**
*
*  Base64 encode / decode
*  Source: http://www.webtoolkit.info/
*  Modified by: @lucascalion - 24/07/2019
*
**/

const _keyStr = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/=";
  
export function encode (input) {
      let output = "";
      let chr1, chr2, chr3, enc1, enc2, enc3, enc4;
      let i = 0;
  
      input = _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 +
            _keyStr.charAt(enc1) + _keyStr.charAt(enc2) +
            _keyStr.charAt(enc3) + _keyStr.charAt(enc4);
  
      }
  
      return output;
}

export function decode (input) {
      let output = "";
      let chr1, chr2, chr3;
      let enc1, enc2, enc3, enc4;
      let 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;
  
}

function  _utf8_encode (string) {
      string = string.replace(/\r\n/g,"\n");
      let utftext = "";
  
      for (let n = 0; n < string.length; n++) {
  
          const 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;
}

function _utf8_decode (utftext) {
      let string = "";
      let i = 0;
      let c, c2, c3;
      c = c2 = 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;
}