smartmeter-app/utils/blufi/crypto/lib/base64-js.js

'use strict';

exports.byteLength = byteLength;
exports.toByteArray = toByteArray;
exports.fromByteArray = fromByteArray;
var lookup = [];
var revLookup = [];
var Arr = typeof Uint8Array !== 'undefined' ? Uint8Array : Array;
var code = 'ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/';

for (var i = 0, len = code.length; i < len; ++i) {
  lookup[i] = code[i];
  revLookup[code.charCodeAt(i)] = i;
} // Support decoding URL-safe base64 strings, as Node.js does.
// See: https://en.wikipedia.org/wiki/Base64#URL_applications


revLookup['-'.charCodeAt(0)] = 62;
revLookup['_'.charCodeAt(0)] = 63;

function getLens(b64) {
  var len = b64.length;

  if (len % 4 > 0) {
    throw new Error('Invalid string. Length must be a multiple of 4');
  } // Trim off extra bytes after placeholder bytes are found
  // See: https://github.com/beatgammit/base64-js/issues/42


  var validLen = b64.indexOf('=');
  if (validLen === -1) validLen = len;
  var placeHoldersLen = validLen === len ? 0 : 4 - validLen % 4;
  return [validLen, placeHoldersLen];
} // base64 is 4/3 + up to two characters of the original data


function byteLength(b64) {
  var lens = getLens(b64);
  var validLen = lens[0];
  var placeHoldersLen = lens[1];
  return (validLen + placeHoldersLen) * 3 / 4 - placeHoldersLen;
}

function _byteLength(b64, validLen, placeHoldersLen) {
  return (validLen + placeHoldersLen) * 3 / 4 - placeHoldersLen;
}

function toByteArray(b64) {
  var tmp;
  var lens = getLens(b64);
  var validLen = lens[0];
  var placeHoldersLen = lens[1];
  var arr = new Arr(_byteLength(b64, validLen, placeHoldersLen));
  var curByte = 0; // if there are placeholders, only get up to the last complete 4 chars

  var len = placeHoldersLen > 0 ? validLen - 4 : validLen;

  for (var i = 0; i < len; i += 4) {
    tmp = revLookup[b64.charCodeAt(i)] << 18 | revLookup[b64.charCodeAt(i + 1)] << 12 | revLookup[b64.charCodeAt(i + 2)] << 6 | revLookup[b64.charCodeAt(i + 3)];
    arr[curByte++] = tmp >> 16 & 0xFF;
    arr[curByte++] = tmp >> 8 & 0xFF;
    arr[curByte++] = tmp & 0xFF;
  }

  if (placeHoldersLen === 2) {
    tmp = revLookup[b64.charCodeAt(i)] << 2 | revLookup[b64.charCodeAt(i + 1)] >> 4;
    arr[curByte++] = tmp & 0xFF;
  }

  if (placeHoldersLen === 1) {
    tmp = revLookup[b64.charCodeAt(i)] << 10 | revLookup[b64.charCodeAt(i + 1)] << 4 | revLookup[b64.charCodeAt(i + 2)] >> 2;
    arr[curByte++] = tmp >> 8 & 0xFF;
    arr[curByte++] = tmp & 0xFF;
  }

  return arr;
}

function tripletToBase64(num) {
  return lookup[num >> 18 & 0x3F] + lookup[num >> 12 & 0x3F] + lookup[num >> 6 & 0x3F] + lookup[num & 0x3F];
}

function encodeChunk(uint8, start, end) {
  var tmp;
  var output = [];

  for (var i = start; i < end; i += 3) {
    tmp = (uint8[i] << 16 & 0xFF0000) + (uint8[i + 1] << 8 & 0xFF00) + (uint8[i + 2] & 0xFF);
    output.push(tripletToBase64(tmp));
  }

  return output.join('');
}

function fromByteArray(uint8) {
  var tmp;
  var len = uint8.length;
  var extraBytes = len % 3; // if we have 1 byte left, pad 2 bytes

  var parts = [];
  var maxChunkLength = 16383; // must be multiple of 3
  // go through the array every three bytes, we'll deal with trailing stuff later

  for (var i = 0, len2 = len - extraBytes; i < len2; i += maxChunkLength) {
    parts.push(encodeChunk(uint8, i, i + maxChunkLength > len2 ? len2 : i + maxChunkLength));
  } // pad the end with zeros, but make sure to not forget the extra bytes


  if (extraBytes === 1) {
    tmp = uint8[len - 1];
    parts.push(lookup[tmp >> 2] + lookup[tmp << 4 & 0x3F] + '==');
  } else if (extraBytes === 2) {
    tmp = (uint8[len - 2] << 8) + uint8[len - 1];
    parts.push(lookup[tmp >> 10] + lookup[tmp >> 4 & 0x3F] + lookup[tmp << 2 & 0x3F] + '=');
  }

  return parts.join('');
}