freeotp-export/export.html

<!--
 * Based on php code by Philip Sharp, converted to javascript by Viljo Viitanen
 *
 * FreeOTP Decoder Javascript
 * 
 * Copyright 2015 Philip Sharp, Viljo Viitanen
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.

-->
<style>
p{margin:50px}
div{margin:10px}
</style>
<a href="https://forge.citizen4.eu/miklo/freeotp-export">Instructions at git</a>
<br>
FreeOTP adb backup file: <input id="file" type="file">
<script src="pako/dist/pako_inflate.js"></script>
<script src="js-untar/build/dist/untar.js"></script>
<script src="qrcodejs/qrcode.min.js"></script>

<script type="text/javascript">

//ported from original PHP function
/**
 * Convert stored secret into otpauth URI parameter
 *
 * Port of encodeInternal() method from Google Authenticator via FreeOTP
 * @link https://fedorahosted.org/freeotp/browser/android/app/src/main/java/com/google/android/apps/authenticator/Base32String.java
 *
 * @param array $data Internal representation of the secret as byte array
 * @return string Secret as Base32 encode string
 */
function encodeSecretBytes(data) {
    DIGITS = ['A','B','C','D','E','F','G','H','I','J','K','L','M','N','O','P','Q','R','S','T','U','V','W','X','Y','Z','2','3','4','5','6','7','']; // 32 chars
    SHIFT = 5; // trailing zeros in binary representation of the size of the alphabet
    MASK = 31; // one less than size of alphabet
    
    // SHIFT is the number of bits per output character, so the length of the
    // output is the length of the input multiplied by 8/SHIFT, rounded up.
    if (data.length >= (1 << 28)) {
        alert('Bad Secret');
    }
    outputLength = (data.length * 8 + SHIFT - 1) / SHIFT;
    result = '';
    buffer = data[0];
    next = 1;
    bitsLeft = 8;
    while (bitsLeft > 0 || next < data.length) {
        if (bitsLeft < SHIFT) {
            if (next < data.length) {
                buffer <<= 8;
                buffer |= (data[next++] & 0xff);
                bitsLeft += 8;
            } else {
                pad = SHIFT - bitsLeft;
                buffer <<= pad;
                bitsLeft += pad;
            }
        }
        index = MASK & (buffer >> (bitsLeft - SHIFT));
        bitsLeft -= SHIFT;
        result += DIGITS[index];
    }
    return result;
}

//small helper function
function querydata(p)
{
  var r= [];
  for (var d in p) {
    r.push(encodeURIComponent(d)+"="+encodeURIComponent(p[d]));
  }
  return r.join("&");
}

function parsexml(param) {
  parser = new DOMParser();
  xml=parser.parseFromString(param, "text/xml");
  s=xml.getElementsByTagName('string');
  if (s.length==0) {
    alert('Cannot parse the file');
  }
  for (var i = 0, len = s.length; i < len; i++) {
    name=s[i].attributes['name'].value;
    if (name == 'tokenOrder') {
      continue;
    }
    j=JSON.parse(s[i].textContent);
    console.log(j);
    issuer = j['issuerInt'] ? j['issuerInt'] : j['issuerExt'];
    issuer = issuer ? issuer : j['issuerAlt'];
    issuer = issuer ? issuer : j['labelAlt'];
    issuer = issuer ? issuer : 'Unknown'+i;
    param={
      'secret'    : encodeSecretBytes(j['secret']),
      'issuer'    : issuer,
      'algorithm' : j['algo'],
      'digits'    : j['digits'],
      'period'    : j['period'],
    }
    label = (j['issuerExt']) ? j['issuerExt']+':'+j['label'] : j['label'];
    uri='otpauth://'+j['type'].toLowerCase()+'/'+encodeURIComponent(label)+'?'+querydata(param);
    console.log(uri);
    document.getElementById("file").insertAdjacentHTML('afterend', '<p><div>'+name+'</div><div id="'+i+'"></div>' );
    new QRCode(document.getElementById(i),uri);
  }
}
 
var reader = new FileReader();

var decoder = new TextDecoder();
if (!decoder) {
   alert ("error: browser does not support TextDecoder")
}

reader.onload = function(event) {
  try {
    decompressed = pako.inflate(event.target.result.slice(24));
  }
  catch(err) {
    alert("cannot decompress the adb backup file: "+err);
    return;
  }
  //argh.. pako doesn't return an arraybuffer, and untar expects an arraybuffer. So...
  var arbuf = new ArrayBuffer(decompressed.byteLength);
  new Uint8Array(arbuf).set(new Uint8Array(decompressed));
  untar(arbuf).then(function(files) {
    var found=0;
    for (var i = 0, len = files.length; i < len; i++) {
      if (files[i].name == "apps/org.fedorahosted.freeotp/sp/tokens.xml") {
        found=1;
        break;
      }
    }
    if (!found) {
      alert("did not find tokens.xml in adb backup file.");
    }
    else {
      parsexml(decoder.decode(files[i].buffer));
    }
  });  
}

document.getElementById("file").onchange=function() {
  reader.readAsArrayBuffer(this.files[0]);
};

</script>