FreeOTP Backup and Recovery

2017-08-30T13:17:00.001-07:00

Make sure adb can see your phone: adb devices
Get a backup of the FreeOTP data: adb backup -f freeotp.bak org.fedorahosted.freeotp
Grab the FreeOTP recovery tarball: https://drive.google.com/file/d/0B20nsfvgGNDgSlp2am9sWkNlalE/view?usp=sharing
This tarball has a built version of android-backup-extractor, and a virtualenv with the python3 dependencies needed and a copy of freeotp-redisplay.py
Install the JCE Unlimited libraries
Install Python3 if not already installed.
Install qrencode (brew install qrencode on OSX)
In the recovery tarball there's https://github.com/nelenkov/android-backup-extractor patched to remove the version check in AndroidBackup.java
java -jar abe-all.jar unpack freeotp.bak freeotp.tar backup_password
tar xvf freeotp.tar
. venv/bin/activate
python3 freeotp-redisplay.py apps/org.fedorahosted.freeotp/sp/tokens.xml

This will print something like:

Image 1: 0123456789ABCDEF - SomeSite:SomeDetails

The Image # is the PNG of a QR code that can be used to move the token to another device.

The Hex code can be passed to oathtool to get a one time token (it assumes SHA1 as the digest algorithm):

Install oathtool ( brew install oath-toolkit on OSX)
Make sure the current time is correct.
oathtool --totp=sha1 0123456789ABCDEF

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Copy of freeotp-redisplay.py:

#!/usr/bin/env python

from __future__ import print_function

import base64

import ctypes

import json

import subprocess

import sys

import xml.etree.ElementTree as ET

from urllib.parse import urlencode

def main():

tree = ET.parse(sys.argv[1])

root = tree.getroot()

assert root.tag == 'map'

count = 0

for child in root:

assert child.tag == 'string'

name = child.attrib['name']

if name == 'tokenOrder':

continue

if ':' in name:

service, user = name.split(':', 1)

else:

user = name

service = 'Unknown'

info = json.loads(child.text)

#print("Info for %s: %r" % (name, info))

# Ensure that we only have unsigned values, then get secret

secret_bytes = [ctypes.c_ubyte(x).value for x in info['secret']]

secret_hex = ''.join('%02X' % (x,) for x in secret_bytes)

secret = bytes.fromhex(secret_hex)

secret_b32 = base64.b32encode(secret)

# Make fancy URL.

params = {

'secret': secret_b32,

'issuer': service,

'counter': info['counter'],

'digits': info['digits'],

'period': info['period'],

'algorithm': info['algo'],

}

tmpl = 'otpauth://{type}/{service}:{user}?{params}'

url = tmpl.format(

type=info['type'].lower(),

service=service,

user=user,

params=urlencode(params),

)

count=count+1

print("Image {0}: {2} - {1}".format(count, name, secret_hex))

process_qrencode = subprocess.Popen(['qrencode', '-o', "qr-{0}.png".format(count), url])

if __name__ == "__main__":

main()

Regular Expressions

FreeOTP Backup and Recovery