Package: django-request-token
Supported versionsThis project supports Django 3.2+ and Python 3.8+. The latest version
supported is Django 4.1 running on Python 3.11.Django Request TokenDjango app that uses JWT to manage one-time and expiring tokens to
protect URLs.This app currently requires the use of PostgreSQL.BackgroundThis project was borne out of our experiences at YunoJuno with 'expiring
links' - which is a common use case of providing users with a URL that
performs a single action, and may bypass standard authentication. A
well-known use of this is the ubiquitous 'unsubscribe' link you find
at the bottom of newsletters. You click on the link and it immediately
unsubscribes you, irrespective of whether you are already authenticated
or not.If you google "temporary url", "one-time link" or something similar you
will find lots of StackOverflow articles on supporting this in Django -
it's pretty obvious, you have a dedicated token url, and you store the
tokens in a model - when they are used you expire the token, and it
can't be used again. This works well, but it falls down in a number of
areas:Hard to support multiple endpoints (views)If you want to support the same functionality (expiring links) for more
than one view in your project, you either need to have multiple models
and token handlers, or you need to store the specific view function and
args in the model; neither of these is ideal.Hard to debugIf you use have a single token url view that proxies view functions, you
need to store the function name, args and it then becomes hard to
support - when someone claims that they clicked onexample.com/t/<token>, you can't tell what that would resolve to
without looking it up in the database - which doesn't work for customer
support.Hard to support multiple scenariosSome links expire, others have usage quotas - some have both. Links may
be for use by a single user, or multiple users.This project is intended to provide an easy-to-support mechanism for
'tokenising' URLs without having to proxy view functions - you can build
well-formed Django URLs and views, and then add request token support
afterwards.Use CasesThis project supports three core use cases, each of which is modelled
using thelogin_modeattribute of a request token:Public link with payloadSingle authenticated request(DEPRECATED: usedjango-visitor-pass)Auto-login(DEPRECATED: usedjango-magic-link)Public Link(RequestToken.LOGIN_MODE_NONE)In this mode (the default for a new token), there is no authentication,
and no assigned user. The token is used as a mechanism for attaching a
payload to the link. An example of this might be a custom registration
or affiliate link, that renders the standard template with additional
information extracted from the token - e.g. the name of the affiliate,
or the person who invited you to register.# a token that can be used to access a public url, without authenticating# as a user, but carrying a payload (affiliate_id).token=RequestToken.objects.create_token(scope="foo",login_mode=RequestToken.LOGIN_MODE_NONE,data={'affiliate_id':1})...@use_request_token(scope="foo")functionview_func(request):# extract the affiliate id from an token _if_ one is suppliedaffiliate_id=(request.token.data['affiliate_id']ifhasattr(request,'token')elseNone)Single Request(RequestToken.LOGIN_MODE_REQUEST)In Request mode, the request.user property is overridden by the user
specified in the token, but only for a single request. This is useful
for responding to a single action (e.g. RSVP, unsubscribe). If the user
then navigates onto another page on the site, they will not be
authenticated. If the user is already authenticated, but as a different
user to the one in the token, then they will receive a 403 response.# this token will identify the request.user as a given user, but only for# a single request - not the entire session.token=RequestToken.objects.create_token(scope="foo",login_mode=RequestToken.LOGIN_MODE_REQUEST,user=User.objects.get(username="hugo"))...@use_request_token(scope="foo")functionview_func(request):assertrequest.user==User.objects.get(username="hugo")Auto-login(RequestToken.LOGIN_MODE_SESSION)This is the nuclear option, and must be treated with extreme care. Using
a Session token will automatically log the user in for an entire
session, giving the user who clicks on the link full access the token
user's account. This is useful for automatic logins. A good example of
this is the email login process on medium.com, which takes an email
address (no password) and sends out a login link.Session tokens have a default expiry of ten minutes.# this token will log in as the given user for the entire session -# NB use with caution.token=RequestToken.objects.create_token(scope="foo",login_mode=RequestToken.LOGIN_MODE_SESSION,user=User.objects.get(username="hugo"))ImplementationThe project contains middleware and a view function decorator that
together validate request tokens added to site URLs.request_token.models.RequestToken- stores the token detailsStep 1 is to create aRequestToken- this has various attributes that
can be used to modify its behaviour, and mandatory property -scope.
This is a text value - it can be anything you like - it is used by the
function decorator (described below) to confirm that the token given
matches the function being called - i.e. thetoken.scopemust match
the function decorator scope kwarg:token=RequestToken(scope="foo")# this will raise a 403 without even calling the function@use_request_token(scope="bar")defincorrect_scope(request):pass# this will call the function as expected@use_request_token(scope="foo")defcorrect_scope(request):passThe token itself - the value that must be appended to links as a
querystring argument - is a JWT - and comes from theRequestToken.jwt()method. For example, if you were sending out an
email, you might render the email as an HTML template like this:{% if token %}<ahref="{{url}}?rt={{token.jwt}}>click here</a>{% else %}<a href="{{url}}">click here</a>{% endif %}If you haven't come across JWT before you can find out more on thejwt.iowebsite. The token produced will include the
following JWT claims (available as the propertyRequestToken.claims:max: maximum times the token can be usedsub: the scopemod: the login modejti: the token idaud: (optional) the user the token representsexp: (optional) the expiration time of the tokeniat: (optional) the time the token was issuedndf: (optional) the not-before-time of the tokenrequest_token.models.RequestTokenLog- stores usage data for tokensEach time a token is used successfully, a log object is written to the
database. This provided an audit log of the usage, and it stores client
IP address and user agent, so can be used to debug issues. This can be
disabled using theREQUEST_TOKEN_DISABLE_LOGSsetting. The logs table
can be maintained using the management command as described below.request_token.middleware.RequestTokenMiddleware- decodes and verifies tokensTheRequestTokenMiddlewarewill look for a querystring token value
(the argument name defaults to 'rt' and can overridden using theJWT_QUERYSTRING_ARGsetting), and if it finds one it will verify the
token (using the JWT decode verification). If the token is verified, it
will fetch the token object from the database and perform additional
validation against the token attributes. If the token checks out it is
added to the incoming request as atokenattribute. This way you can
add arbitrary data (stored on the token) to incoming requests.If the token has a user specified, then therequest.useris updated to
reflect this. The middleware must run after the Django auth middleware,
and before any custom middleware that inspects / monkey-patches therequest.user.If the token cannot be verified it returns a 403.request_token.decorators.use_request_token- applies token
permissions to viewsA function decorator that takes one mandatory kwargs (scope) and one
optional kwargs (required). Thescopeis used to match tokens to
view functions - it's just a straight text match - the value can be
anything you like, but if the token scope is 'foo', then the
corresponding view function decorator scope must match. Therequiredkwarg is used to indicate whether the viewmusthave a token in
order to be used, or not. This defaults to False - if a tokenisprovided, then it will be validated, if not, the view function is called
as is.If the scopes do not match then a 403 is returned.If required is True and no token is provided the a 403 is returned.InstallationDownload / install the app using pip:pipinstalldjango-request-tokenAdd the apprequest_tokento yourINSTALLED_APPSDjango setting:# settings.pyINSTALLED_APPS=('django.contrib.admin','django.contrib.auth','django.contrib.contenttypes','django.contrib.sessions','django.contrib.messages','django.contrib.staticfiles','request_token',...)Add the middleware to your settings,afterthe standard
authentication middleware, and before any custom middleware that uses
therequest.user.MIDDLEWARE_CLASSES=[# default django middleware'django.contrib.sessions.middleware.SessionMiddleware','django.middleware.common.CommonMiddleware','django.middleware.csrf.CsrfViewMiddleware','django.contrib.auth.middleware.AuthenticationMiddleware','django.contrib.messages.middleware.MessageMiddleware','request_token.middleware.RequestTokenMiddleware',]You can now addRequestTokenobjects, either via the shell (or within
your app) or through the admin interface. Once you have added aRequestTokenyou can add the token JWT to your URLs (using thejwt()method):>>>token=RequestToken.objects.create_token(scope="foo")>>>url="https://example.com/foo?rt="+token.jwt()You now have a request token enabled URL. You can use this token to
protect a view function using the view decorator:@use_request_token(scope="foo")functionfoo(request):passNB The 'scope' argument to the decorator is used to bind the function to
the incoming token - if someone tries to use a valid token on another
URL, this will return a 403.NB this currently supports only view functions - not class-based views.Management commandsThere is a single management command,truncate_request_token_logwhich can
be used to manage the size of the log table (each token usage is logged to
the database). It supports two arguments ---max-countand--max-dayswhich
are self-explanatory:$ python manage.py truncate_request_token_log --max-count=100
Truncating request token log records:
-> Retaining last 100 request token log records
-> Truncating request token log records from 2021-08-01 00:00:00
-> Truncating 0 request token log records.
$SettingsREQUEST_TOKEN_QUERYSTRINGThe querystring argument name used to extract the token from incoming
requests, defaults tort.REQUEST_TOKEN_EXPIRYSession tokens have a default expiry interval, specified in minutes. The
primary use case (above) dictates that the expiry should be no longer
than it takes to receive and open an email, defaults to10(minutes).REQUEST_TOKEN_403_TEMPLATESpecifying the 403-template so that for prettyfying the 403-response,
in production with a setting like:FOUR03_TEMPLATE=os.path.join(BASE_DIR,'...','403.html')REQUEST_TOKEN_DISABLE_LOGSSet toTrueto disable the creation ofRequestTokenLogobjects on
each use of a token. This is not recommended in production, as the
auditing of token use is a valuable part of the library.TestsThere is a set oftoxtests.LicenseMITContributingThis is by no means complete, however, it's good enough to be of value, hence releasing it.
If you would like to contribute to the project, usual Github rules apply:Fork the repo to your own accountSubmit a pull requestAdd tests for any new codeFollow coding style of existing projectAcknowledgements@jpadilla forPyJWT