onetimepass 1.0.1
Module for generating and validating HOTP and TOTP tokens
License: MIT

Versions
========

Current development release: `onetimepass-master.tar.gz`_ |otp-status-dev|_

.. |otp-status-dev| image::
   https://api.travis-ci.org/tadeck/onetimepass.png?branch=master
.. _otp-status-dev: https://travis-ci.org/tadeck/onetimepass
.. _onetimepass-master.tar.gz:
   https://github.com/tadeck/onetimepass/archive/master.tar.gz

Changelog
---------

+---------+------------+------------------------------------------------------+
| Version | Date       | Changes                                              |
+=========+============+======================================================+
| 1.0.1   | 2015-07-31 | - fixed tests and build system,                      |
|         |            | - extended test coverage with Py3.5, PyPy and PyPy3, |
+---------+------------+------------------------------------------------------+
| 1.0.0   | 2015-07-31 | - skipping spaces if they are given in secret,       |
|         |            | - test suite made more reliable,                     |
+---------+------------+------------------------------------------------------+
| 0.3.0   | 2014-08-16 | - configurable digest method,                        |
|         |            | - configurable token length,                         |
|         |            | - configurable TOTP interval length,                 |
+---------+------------+------------------------------------------------------+
| 0.2.2   | 2013-07-12 | - license clarification,                             |
|         |            | - removal of compiled documentation from the sources,|
+---------+------------+------------------------------------------------------+
| 0.2.1   | 2013-07-12 | - support for unicode secrets,                       |
|         |            | - preliminary support for Travis CI,                 |
+---------+------------+------------------------------------------------------+
| 0.2.0   | 2013-04-11 | - added compatibility with Python 3.x,               |
|         |            | - removed compatibility with Python 2.5 and earlier, |
+---------+------------+------------------------------------------------------+
| 0.1.2   | 2013-01-23 | - added automated case fold to secret,               |
+---------+------------+------------------------------------------------------+
| 0.1.1   | 2013-12-20 | - internal code improvements,                        |
|         |            | - documentation,                                     |
+---------+------------+------------------------------------------------------+
| 0.1.0   | 2011-12-19 | (initial public release)                             |
+---------+------------+------------------------------------------------------+

What is OneTimePass
===================

OneTimePass (actually ``onetimepass``) is a module for generating one-time
passwords, namely HOTPs (HMAC-based one-time passwords) and TOTPs (time-based
one-time passwords). They are used eg. within Google Authenticator application
for Android or iPhone.

How to install
==============

To install the library, you can either use ``pip``, or just download it
separately. Installing in ``pip`` is the simplest. Assuming you are installing
it system-wide::

    $ sudo pip install onetimepass

(if you are installing it in virtualenv, you do not need "``sudo``" part).

Alternatively, you can follow the download link above and unpack in some
directory on your ``sys.path``, or clone it as Git submodule to your own
directory.

How to use OneTimePass
======================

You can use this module in the following way:

1. Install module (download it into your application's directory or into modules
   directory)
2. To get time-based token you invoke it like that::

       import onetimepass as otp
       my_secret = 'MFRGGZDFMZTWQ2LK'
       my_token = otp.get_totp(my_secret)

.. note::
    ``my_secret`` is case-insensitive, also spaces are ignored. This means you
    can provide your users with more readable representations of the secrets
    (eg. ``mfrg gzdf mztw q2lk`` instead of ``MFRGGZDFMZTWQ2LK``) and pass them
    unchanged to library. Same applies to other functions accepting secrets in
    this library.

3. To get HMAC-based token you invoke it like that::

       import onetimepass as otp
       my_secret = 'MFRGGZDFMZTWQ2LK'
       my_token = otp.get_hotp(my_secret, intervals_no=3)

   where ``intervals_no`` is the number of the current trial (if checking on
   the server, you have to check several values, higher than the last
   successful one, determined for previous successful authentications).

4. To check time-based token you invoke it like that::

       import onetimepass as otp
       my_secret = 'MFRGGZDFMZTWQ2LK'
       my_token = 123456 # should be probably from some user's input
       is_valid = otp.valid_totp(token=my_token, secret=my_secret)

5. To check HMAC-based token you invoke it like that::

       import onetimepass as otp
       my_secret = 'MFRGGZDFMZTWQ2LK'
       my_token = 123456 # should be probably from some user's input
       last_used = 5 # store last valid interval somewhere else
       is_valid = otp.valid_hotp(token=my_token, secret=my_secret, last=last_used)

   where:

   - ``last`` argument (in this case being assigned ``last_used``) is the
     number of the last successfully checked interval number (as
     ``valid_totp()`` will skip it and start checking from the next interval
     number)
   - ``is_valid`` is being assigned value of ``False`` if ``my_token`` has not
     been identified as valid OTP for given secret (``my_secret``) and checked
     interval range. If it has been successful, ``is_valid`` is assigned a
     number of the working interval number (it should be saved into the
     database and supplied to the function as ``last`` argument next time the
     password is being checked, so you cannot use the same token again).

License
=======

License for this library is available in ``LICENSE.rst`` file, in the same
directory. Online version is available here_.

.. _here: https://github.com/tadeck/onetimepass/blob/master/README.rst