Open source two-factor authentication for Android
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README.md

andOTP - Android OTP Authenticator

Build Status Current release Crowdin Chat - Telegram Chat - Matrix

andOTP

andOTP is a two-factor authentication App for Android 4.4+.

It implements Time-based One-time Passwords (TOTP) and HMAC-Based One-Time Passwords (HOTP). Simply scan the QR code and login with the generated 6-digit code.

This project started out as a fork of the great OTP Authenticator app written by Bruno Bierbaumer, which has sadly been inactive since 2015. By now almost every aspect of the app has been changed/re-written so the fork status of the Github repository got detached upon user request. But all credit for the original version and for starting this project still goes to Bruno!

Help wanted:

I currently don't have that much time to spend developing andOTP, so any contributions are always welcome. Don't worry, I will still continue to develop andOTP it will just slow down from the incredible speed I had going in the beginning.

Features:

  • Free and Open-Source
  • Requires minimal permissions
    • Camera access for QR code scanning
    • Storage access for import and export of the database
  • Encrypted storage with two backends:
    • Android KeyStore
    • Password / PIN
  • Multiple backup options:
    • Plain-text
    • Password-protected
    • OpenPGP-encrypted
  • Sleek minimalistic Material Design with three different themes:
    • Light
    • Dark
    • Black (for OLED screens)
  • Great Usability
  • Compatible with Google Authenticator
  • Supported algorithms:
    • TOTP (Time-based One-time Passwords) as specified in RFC 6238
    • HOTP (HMAC-based One-time Passwords) as specified in RFC 4226

Backups:

To keep your account information as secure as possible andOTP only stores it in encrypted data files. A part of the encryption key used for that is stored in the Android KeyStore system. The advantage of this approach is that the key is kept separate from the apps data and, as a bonus, can be backed by hardware cryptography (if your device supports this).

However, due to that separation, backups with 3rd-party apps like Titanium Backup can not be used with andOTP. Such apps only backup the encrypted data files and not the encryption key, which renders them useless.

Please only use the internal backup functions provided by andOTP to backup your accounts! Everything else WILL result in data loss.

Opening the backups on your PC:

  • OpenPGP: OpenPGP can be used to easily decrypt the OpenPGP-encrypted backups on your PC.
  • andOTP-decrypt: A python script written by @asmw to decrypt password-protected backups on your PC (needs more testing).

Automatic backups:

  • BroadcastReceivers: AndOTP supports a number of broadcasts to perform automated backups, eg. via Tasker. These will get saved to the defined backup directory. These only work when KeyStore is used as the encryption mechanism
    • org.shadowice.flocke.andotp.broadcast.PLAIN_TEXT_BACKUP: Perform a plain text backup. WARNING: This will save your 2FA tokens onto the disk in an unencrypted manner!
    • org.shadowice.flocke.andotp.broadcast.ENCRYPTED_BACKUP: Perform an encrypted backup of your 2FA database using the selected password in settings.

Migration:

Check out this wiki page to learn about the different ways to migrate to andOTP from other 2FA apps.

Downloads:

Get it on Google Play Get it on F-Droid Get it on GitHub

Warning: All three versions (Google Play, F-Droid and the APKs) are not compatible (not signed by the same key)! You will have to uninstall one to install the other, which will delete all your data. So make sure you have a current backup before switching!

Contribute:

  • Translation: If you want to help translate andOTP into your language head over to the Crowdin project.
  • Bug reports and feature requests: You can report bugs and request features in the Issue tracker on GitHub.
  • Requesting thumbnails: If you are missing a thumbnail you can request it by editing the wiki
  • Discussion and support:
    • XDA thread (please keep off-topic to a minimum)
    • Telegram group @andOTP (if you just want important updates you can mute the group so you only get notified about pinned messages)

Developers:

Screenshots:

Light theme:

Main Activity Settings Activity Backup Activity

Dark theme:

Main Activity Settings Activity Backup Activity

Black theme:

Main Activity Settings Activity Backup Activity

Acknowledgments:

Open-source components used:

Code examples used:

Previously used open-source components:

Previously used code examples:

License:

Copyright (C) 2017-2018 Jakob Nixdorf <flocke@shadowice.org>
Copyright (C) 2015 Bruno Bierbaumer

Permission is hereby granted, free of charge, to any person obtaining a copy of
this software and associated documentation files (the "Software"), to deal in the
Software without restriction, including without limitation the rights to
use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of
the Software, and to permit persons to whom the Software is furnished to do so,
subject to the following conditions:

The above copyright notice and this permission notice shall be included in all
copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED,
INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR
PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,
TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE
OR OTHER DEALINGS IN THE SOFTWARE.