Included ab file parsing

README.md

@@ -10,9 +10,9 @@ __Be sure to understand the security implications of backing up the secrets from
 
 # Instructions
 
-Make an adb backup of FreeOTP, extract the backup file (details on how to do this are currenly left as an excercise for the reader). Open the tokens.xml file (path is apps/org.fedorahosted.freeotp/sp) with this app. Read the displayed qrcodes with the authenticator app on your other phone.
+Make an adb backup of FreeOTP, (details on how to do this are currenly left as an excercise for the reader. While you are doing the backup, consider the above warning!). Open the adb backup file (.ab) with this app. Read the displayed qrcodes with the authenticator app on your other phone.
 
-The author has tested the app with current Google Chrome and Mozilla Firefox on Ubuntu 14.04 in September 2015, generated qrcodes have been succesfully imported in FreeOTP and Google Authenticator on Android and Microsoft Authenticator on Windows Phone 8.
+The author has tested the app with current Google Chrome and Mozilla Firefox on Ubuntu 14.04 in September 2015, generated qrcodes have been succesfully imported in FreeOTP and Google Authenticator on Android and Microsoft Authenticator on Windows Phone 8. Other browsers probably do not work.
 
 This app can be opened directly at https://rawgit.com/viljoviitanen/freeotp-export/master/export.html 
 
@@ -28,6 +28,12 @@ Based on https://github.com/philipsharp/FreeOTPDecoder (Apache license)
 
 Uses https://github.com/davidshimjs/qrcodejs (MIT license)
 
+Uses https://github.com/nodeca/pako (MIT license)
+
+Uses https://github.com/Qvazar/js-untar (GPLv3 license)
+
+Content is served by https://rawgit.com/
+
 # License
 
 Apache License, Version 2.0

export.html

@@ -17,10 +17,6 @@
  * See the License for the specific language governing permissions and
  * limitations under the License.
 
-NOTE: adb backup files can be extracted with the following one-liner on linux:
-
-dd if=backup.ab bs=1 skip=24 | python -c "import zlib,sys;sys.stdout.write(zlib.decompress(sys.stdin.read()))" | tar -xvf -
-
 -->
 <style>
 p{margin:50px}
@@ -28,8 +24,10 @@ div{margin:10px}
 </style>
 <a href="https://github.com/viljoviitanen/freeotp-export">Instructions at github</a>
 <br>
-<input id="file" type="file">
-<script src="https://cdn.rawgit.com/viljoviitanen/qrcodejs/master/qrcode.min.js"></script>
+FreeOTP adb backup file: <input id="file" type="file">
+<script src="https://rawgit.com/nodeca/pako/master/dist/pako_inflate.js"></script>
+<script src="https://rawgit.com/Qvazar/js-untar/master/build/dist/untar.js"></script>
+<script src="https://rawgit.com/viljoviitanen/qrcodejs/master/qrcode.min.js"></script>
 <script type="text/javascript">
 
 //ported from original PHP function
@@ -86,11 +84,9 @@ function querydata(p)
   return r.join("&");
 }
 
-var reader = new FileReader();
-
-reader.onload = function(event) {
+function parsexml(param) {
   parser = new DOMParser();
-  xml=parser.parseFromString(event.target.result, "text/xml");
+  xml=parser.parseFromString(param, "text/xml");
   s=xml.getElementsByTagName('string');
   if (s.length==0) {
     alert('Cannot parse the file');
@@ -109,15 +105,50 @@ reader.onload = function(event) {
       'period'    : j['period'],
     }
     label = (j['issuerExt']) ? j['issuerExt']+':'+j['label'] : j['label'];
-    uri='otpauth://'+j['type'].toLowerCase()+'/'+encodeURIComponent(label)+'?'+querydata(param);
+    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.readAsText(this.files[0]);
+  reader.readAsArrayBuffer(this.files[0]);
 };
 
 </script>