ftw.tokenauth
=============
PAS plugin that facilitates **machine-to-machine authentication** by
implementing a two legged OAuth2 flow using service keys and short-lived
access tokens.
Installation
============
- Add ``ftw.tokenauth`` to your buildout configuration or as a dependency
of your policy package:
.. code:: ini
[instance]
eggs +=
ftw.tokenauth
- Install the generic setup profile of ``ftw.tokenauth``.
Configuration
=============
For a user to be allowed to issue (or otherwise manage) service keys, they
require the ``ftw.tokenauth: Manage own Service Keys`` permission. So
integration packages need to assign this permission to roles that should be
allowed to use service keys.
Authentication flow
===================
The authentication flow involves four steps:
1. A logged in service user issues a service key in Plone, and stores the
private key in a safe location accessible to the client application.
2. The client application uses the private key to create and sign a JWT
authorization grant.
3. The client application exchanges the JWT authorization grant for a
short-lived access token at the ``@@oauth2-token`` endpoint.
4. The client then uses this access token to authenticate requests to
protected resources.
Assuming the client is in possession of a service key, the flow looks like this:
.. image:: https://github.com/4teamwork/ftw.tokenauth/raw/master/docs/authentication-flow.png
..
Image Source: https://drive.google.com/open?id=1F8C4QB57ALF705vx9xkTDIX8AqMCJ30v
Basic Usage
===========
In order to set up machine-to-machine authentication for a client, the
following steps need to be performed:
1. Issue Service Key
--------------------
A user that has already authenticated to Plone using regular means, and has
the ``ftw.tokenauth: Manage own Service Keys`` permission, can issue service
keys for their account via the ``@@manage-service-keys`` view
(``Manage Service Keys`` action in personal tools menu).
.. image:: https://github.com/4teamwork/ftw.tokenauth/raw/master/docs/manage-service-keys.png
They need to issue a service key that is then displayed **exactly once** for
download, and store the private key in a safe location accessible to the
client that will use it.
.. image:: https://github.com/4teamwork/ftw.tokenauth/raw/master/docs/issue-service-key.png
`IP range restrictions`_ may also be defined when issuing a key.
TODO: Document Key revocation.
2. Create and sign JWT authorization grant using service key
------------------------------------------------------------
In order to request an access token, the client application then uses the
private service key to create and sign a JWT.
The JWT needs to contain the following claims:
==== ========================================================================
Name Description
==== ========================================================================
iss Issuer - must be ``client_id`` from service key
aud Audience - must be ``token_uri`` from service key
sub Subject - must be ``user_id`` from service key or an arbitrary userid of
an existing user if the service key user is allowed to impersonate other
users.
iat The time the assertion was issued, specified as seconds since
00:00:00 UTC, January 1, 1970.
exp The expiration time of the assertion, specified as seconds since
00:00:00 UTC, January 1, 1970. This value has a maximum of 1 hour after
the issued time.
==== ========================================================================
The JWT then needs to be signed with the private key. The only supported
signature algorithm is ``RS256``.
Python Example:
.. code:: python
import json
import jwt
import time
# Load saved key from filesystem
service_key = json.load(open('my_saved_key.json', 'rb'))
private_key = service_key['private_key'].encode('utf-8')
claim_set = {
"iss": service_key['client_id'],
"sub": service_key['user_id'],
"aud": service_key['token_uri'],
"iat": int(time.time()),
"exp": int(time.time() + (60 * 60)),
}
grant = jwt.encode(claim_set, private_key, algorithm='RS256')
3. Token request (exchange JWT grant for an access token)
---------------------------------------------------------
The client then makes a token request to the ``token_uri`` with the JWT grant
it created.
This request needs to be a ``POST`` request with
``Content-Type: application/x-www-form-urlencoded`` and a request body that
contains the form encoded parameters.
Two parameters are required:
=========== =================================================================
Name Description
=========== =================================================================
grant_type Must always be ``urn:ietf:params:oauth:grant-type:jwt-bearer``
assertion The JWT authorization grant
=========== =================================================================
The token endpoint will then respond with a token response containing the
access token:
.. code:: json
{
"access_token": "<token>",
"expires_in": 3600,
"token_type": "Bearer"
}
The response will be of ``Content-Type: application/json`` and contain a JSON
encoded body.
Python Example:
.. code:: python
import requests
GRANT_TYPE = 'urn:ietf:params:oauth:grant-type:jwt-bearer'
payload = {'grant_type': GRANT_TYPE, 'assertion': grant}
response = requests.post(service_key['token_uri'], data=payload)
token = response.json()['access_token']
TODO: Document error responses for token requests
4. Use access token to authenticate requests
--------------------------------------------
The client can then use the access token to authenticate requests. The token
needs to be sent in the HTTP ``Authorization`` header as a ``Bearer`` token.
Once the token expires, the client must create a JWT authorization grant again,
and request a new access token.
Python Example:
.. code:: python
with requests.Session() as session:
session.headers.update({'Authorization': 'Bearer %s' % token})
response = session.get('http://localhost:8080/Plone/')
# ...
If the token used by the client is expired, the server will respond with an
error response:
.. code:: json
{
"error": "invalid_token",
"error_description": "Access token expired"
}
The client should then sign another JWT authentication grant, request a new
token, and re-dispatch the failed request with the original parameters, and
the new token.
Recommended Client Implementation
=================================
The recommended logic to implement on a client to repeatedly authenticate and
obtain new access tokens looks something like this:
.. image:: https://github.com/4teamwork/ftw.tokenauth/raw/master/docs/client-flow.png
..
Image Source: https://drive.google.com/open?id=1wVua7R5VQUxJKGL8dq1kGV4AjLgjGSXZ
The client should, instead of trying to predict access token expiration, just
anticipate the case that authentication using an existing token will fail
(because the token expired), and then perform the necessary steps to obtain
a new token.
To accomplish this, it is recommended to delegate all the requests a client
application wants to make to a class that expects an ``Access token expired``
response as described above, and obtains a new token if necessary. The failed
request that lead to the error response then needs to be re-dispatched with
its original parameters, but then new token in the ``Authorization`` header.
Care needs to be taken to **not** include an expired token (or any
``Authorization`` header for that matter) with the requests to the token
endpoint when obtaining a new token.
An example implementation in Python can be found in
`docs/client-example.py <https://github.com/4teamwork/ftw.tokenauth/blob/master/docs/client-example.py>`_.
Advanced use
============
This section covers some more advanced settings and functionality of
``ftw.tokenauth``.
IP range restrictions
---------------------
When issuing a key, IP range restrictions may be defined that limit from what
source IP address access tokens tied to this key may be used.
Changes to IP range restrictions for a given key are effective immediately,
and also affect already issued tokens tied to this key.
IP ranges may be specified as a single IP address or as a network in
`CIDR notation <https://en.wikipedia.org/wiki/Classless_Inter-Domain_Routing#CIDR_notation>`_
using the slash-suffix.
Multiple ranges may be provided in comma-separated form.
Examples of valid IP range specifications:
- ``192.168.1.1``
- ``192.168.0.0/16``
- ``192.168.1.1, 10.0.0.0/8``
Authentication attempts from an unauthorized source IP address are logged
server side, but not indicated to the client in any particular way -
authentication is simply not performed.
Impersonation
-------------
Impersonation allows to authenticate as an arbitrary user instead of the user
who issued the service key. This is useful if e.g. an application needs to act
in the context of different users.
To be able to impersonate another user the service key user needs the
permission ``ftw.tokenauth: Impersonate user``. By default this permission is
granted to the ``Manager`` role only. Be aware that with this permission a user
is allowed to impersonate users with higher privileges and thus in fact gets
all the permissions of the highest privileged user in the system.
To impersonate a user pass his userid or loginname instead of the userid
of the service key user with the ``sub`` claim in the JWT token when
requesting an access token.
Usage logs
----------
In the "Manage Service Keys" view, the last use of a key to issue access
tokens is listed in the "Last Used" column. Clicking on this timestamp
displays a detailed log of most recent uses of the key.
By default, these logs list the uses of the key in the last 7 days (the
usage log retention period can be configured as a property on the PAS Plugin
via the ZMI).
The log entry with the most recent use of a key is always retained, while
the other log entries are cleaned out if they're expired (cleanup happens
whenever a any new access token is issued).
The logs don't show use of access tokens to authenticate, but instead they
show every instance where JWT authentication grants signed with this key
were used to obtain a new access token.
Links
=====
- Github: https://github.com/4teamwork/ftw.tokenauth
- Issues: https://github.com/4teamwork/ftw.tokenauth/issues
- Continuous integration: https://jenkins.4teamwork.ch/search?q=ftw.tokenauth
Copyright
=========
This package is copyright by `4teamwork <http://www.4teamwork.ch/>`_.
``ftw.tokenauth`` is licensed under GNU General Public License, version 2.
Changelog
=========
1.2.0 (2023-12-13)
------------------
- Add fallback user lookup by username (login).
[phgross]
1.1.0 (2018-07-12)
------------------
- Allow to impersonate another user.
[buchi]
1.0.1 (2018-04-16)
------------------
- Switch to `ipaddress` module instead of `py2-ipaddress` for IP range
parsing, and fix unicode handling.
[lgraf]
1.0.0 (2018-04-04)
------------------
- Initial implementation
[lgraf]
Raw data
{
"_id": null,
"home_page": "https://github.com/4teamwork/ftw.tokenauth",
"name": "ftw.tokenauth",
"maintainer": "",
"docs_url": null,
"requires_python": "",
"maintainer_email": "",
"keywords": "token authentication plone oauth2 jwt",
"author": "4teamwork AG",
"author_email": "mailto:info@4teamwork.ch",
"download_url": "https://files.pythonhosted.org/packages/93/90/b0cc87bf82dd11cf3cb6d01696153e29e2c533b101c1d8c5eff0f350daca/ftw.tokenauth-1.2.0.tar.gz",
"platform": null,
"description": "ftw.tokenauth\n=============\n\nPAS plugin that facilitates **machine-to-machine authentication** by\nimplementing a two legged OAuth2 flow using service keys and short-lived\naccess tokens.\n\nInstallation\n============\n\n- Add ``ftw.tokenauth`` to your buildout configuration or as a dependency\n of your policy package:\n\n.. code:: ini\n\n [instance]\n eggs +=\n ftw.tokenauth\n\n- Install the generic setup profile of ``ftw.tokenauth``.\n\n\nConfiguration\n=============\n\nFor a user to be allowed to issue (or otherwise manage) service keys, they\nrequire the ``ftw.tokenauth: Manage own Service Keys`` permission. So\nintegration packages need to assign this permission to roles that should be\nallowed to use service keys.\n\n\nAuthentication flow\n===================\n\nThe authentication flow involves four steps:\n\n1. A logged in service user issues a service key in Plone, and stores the\n private key in a safe location accessible to the client application.\n\n2. The client application uses the private key to create and sign a JWT\n authorization grant.\n\n3. The client application exchanges the JWT authorization grant for a\n short-lived access token at the ``@@oauth2-token`` endpoint.\n\n4. The client then uses this access token to authenticate requests to\n protected resources.\n\n\nAssuming the client is in possession of a service key, the flow looks like this:\n\n.. image:: https://github.com/4teamwork/ftw.tokenauth/raw/master/docs/authentication-flow.png\n\n..\n Image Source: https://drive.google.com/open?id=1F8C4QB57ALF705vx9xkTDIX8AqMCJ30v\n\n\n\nBasic Usage\n===========\n\nIn order to set up machine-to-machine authentication for a client, the\nfollowing steps need to be performed:\n\n1. Issue Service Key\n--------------------\n\nA user that has already authenticated to Plone using regular means, and has\nthe ``ftw.tokenauth: Manage own Service Keys`` permission, can issue service\nkeys for their account via the ``@@manage-service-keys`` view\n(``Manage Service Keys`` action in personal tools menu).\n\n.. image:: https://github.com/4teamwork/ftw.tokenauth/raw/master/docs/manage-service-keys.png\n\nThey need to issue a service key that is then displayed **exactly once** for\ndownload, and store the private key in a safe location accessible to the\nclient that will use it.\n\n.. image:: https://github.com/4teamwork/ftw.tokenauth/raw/master/docs/issue-service-key.png\n\n`IP range restrictions`_ may also be defined when issuing a key.\n\nTODO: Document Key revocation.\n\n2. Create and sign JWT authorization grant using service key\n------------------------------------------------------------\n\nIn order to request an access token, the client application then uses the\nprivate service key to create and sign a JWT.\n\nThe JWT needs to contain the following claims:\n\n==== ========================================================================\nName Description\n==== ========================================================================\niss Issuer - must be ``client_id`` from service key\naud Audience - must be ``token_uri`` from service key\nsub Subject - must be ``user_id`` from service key or an arbitrary userid of\n an existing user if the service key user is allowed to impersonate other\n users.\niat The time the assertion was issued, specified as seconds since\n 00:00:00 UTC, January 1, 1970.\nexp The expiration time of the assertion, specified as seconds since\n 00:00:00 UTC, January 1, 1970. This value has a maximum of 1 hour after\n the issued time.\n==== ========================================================================\n\nThe JWT then needs to be signed with the private key. The only supported\nsignature algorithm is ``RS256``.\n\n\nPython Example:\n\n.. code:: python\n\n import json\n import jwt\n import time\n\n # Load saved key from filesystem\n service_key = json.load(open('my_saved_key.json', 'rb'))\n\n private_key = service_key['private_key'].encode('utf-8')\n\n claim_set = {\n \"iss\": service_key['client_id'],\n \"sub\": service_key['user_id'],\n \"aud\": service_key['token_uri'],\n \"iat\": int(time.time()),\n \"exp\": int(time.time() + (60 * 60)),\n }\n grant = jwt.encode(claim_set, private_key, algorithm='RS256')\n\n\n3. Token request (exchange JWT grant for an access token)\n---------------------------------------------------------\n\nThe client then makes a token request to the ``token_uri`` with the JWT grant\nit created.\n\nThis request needs to be a ``POST`` request with\n``Content-Type: application/x-www-form-urlencoded`` and a request body that\ncontains the form encoded parameters.\n\nTwo parameters are required:\n\n=========== =================================================================\nName Description\n=========== =================================================================\ngrant_type Must always be ``urn:ietf:params:oauth:grant-type:jwt-bearer``\nassertion The JWT authorization grant\n=========== =================================================================\n\nThe token endpoint will then respond with a token response containing the\naccess token:\n\n.. code:: json\n\n {\n \"access_token\": \"<token>\",\n \"expires_in\": 3600,\n \"token_type\": \"Bearer\"\n }\n\nThe response will be of ``Content-Type: application/json`` and contain a JSON\nencoded body.\n\nPython Example:\n\n.. code:: python\n\n import requests\n\n GRANT_TYPE = 'urn:ietf:params:oauth:grant-type:jwt-bearer'\n\n payload = {'grant_type': GRANT_TYPE, 'assertion': grant}\n response = requests.post(service_key['token_uri'], data=payload)\n token = response.json()['access_token']\n\n\nTODO: Document error responses for token requests\n\n\n4. Use access token to authenticate requests\n--------------------------------------------\n\nThe client can then use the access token to authenticate requests. The token\nneeds to be sent in the HTTP ``Authorization`` header as a ``Bearer`` token.\n\nOnce the token expires, the client must create a JWT authorization grant again,\nand request a new access token.\n\nPython Example:\n\n.. code:: python\n\n with requests.Session() as session:\n session.headers.update({'Authorization': 'Bearer %s' % token})\n response = session.get('http://localhost:8080/Plone/')\n # ...\n\nIf the token used by the client is expired, the server will respond with an\nerror response:\n\n.. code:: json\n\n {\n \"error\": \"invalid_token\",\n \"error_description\": \"Access token expired\"\n }\n\nThe client should then sign another JWT authentication grant, request a new\ntoken, and re-dispatch the failed request with the original parameters, and\nthe new token.\n\n\nRecommended Client Implementation\n=================================\n\nThe recommended logic to implement on a client to repeatedly authenticate and\nobtain new access tokens looks something like this:\n\n.. image:: https://github.com/4teamwork/ftw.tokenauth/raw/master/docs/client-flow.png\n\n..\n Image Source: https://drive.google.com/open?id=1wVua7R5VQUxJKGL8dq1kGV4AjLgjGSXZ\n\n\nThe client should, instead of trying to predict access token expiration, just\nanticipate the case that authentication using an existing token will fail\n(because the token expired), and then perform the necessary steps to obtain\na new token.\n\nTo accomplish this, it is recommended to delegate all the requests a client\napplication wants to make to a class that expects an ``Access token expired``\nresponse as described above, and obtains a new token if necessary. The failed\nrequest that lead to the error response then needs to be re-dispatched with\nits original parameters, but then new token in the ``Authorization`` header.\n\nCare needs to be taken to **not** include an expired token (or any\n``Authorization`` header for that matter) with the requests to the token\nendpoint when obtaining a new token.\n\nAn example implementation in Python can be found in\n`docs/client-example.py <https://github.com/4teamwork/ftw.tokenauth/blob/master/docs/client-example.py>`_.\n\n\nAdvanced use\n============\n\nThis section covers some more advanced settings and functionality of\n``ftw.tokenauth``.\n\nIP range restrictions\n---------------------\n\nWhen issuing a key, IP range restrictions may be defined that limit from what\nsource IP address access tokens tied to this key may be used.\n\nChanges to IP range restrictions for a given key are effective immediately,\nand also affect already issued tokens tied to this key.\n\nIP ranges may be specified as a single IP address or as a network in\n`CIDR notation <https://en.wikipedia.org/wiki/Classless_Inter-Domain_Routing#CIDR_notation>`_\nusing the slash-suffix.\n\nMultiple ranges may be provided in comma-separated form.\n\nExamples of valid IP range specifications:\n\n- ``192.168.1.1``\n- ``192.168.0.0/16``\n- ``192.168.1.1, 10.0.0.0/8``\n\nAuthentication attempts from an unauthorized source IP address are logged\nserver side, but not indicated to the client in any particular way -\nauthentication is simply not performed.\n\nImpersonation\n-------------\n\nImpersonation allows to authenticate as an arbitrary user instead of the user\nwho issued the service key. This is useful if e.g. an application needs to act\nin the context of different users.\n\nTo be able to impersonate another user the service key user needs the\npermission ``ftw.tokenauth: Impersonate user``. By default this permission is\ngranted to the ``Manager`` role only. Be aware that with this permission a user\nis allowed to impersonate users with higher privileges and thus in fact gets\nall the permissions of the highest privileged user in the system.\n\nTo impersonate a user pass his userid or loginname instead of the userid\nof the service key user with the ``sub`` claim in the JWT token when\nrequesting an access token.\n\nUsage logs\n----------\n\nIn the \"Manage Service Keys\" view, the last use of a key to issue access\ntokens is listed in the \"Last Used\" column. Clicking on this timestamp\ndisplays a detailed log of most recent uses of the key.\n\nBy default, these logs list the uses of the key in the last 7 days (the\nusage log retention period can be configured as a property on the PAS Plugin\nvia the ZMI).\n\nThe log entry with the most recent use of a key is always retained, while\nthe other log entries are cleaned out if they're expired (cleanup happens\nwhenever a any new access token is issued).\n\nThe logs don't show use of access tokens to authenticate, but instead they\nshow every instance where JWT authentication grants signed with this key\nwere used to obtain a new access token.\n\n\nLinks\n=====\n\n- Github: https://github.com/4teamwork/ftw.tokenauth\n- Issues: https://github.com/4teamwork/ftw.tokenauth/issues\n- Continuous integration: https://jenkins.4teamwork.ch/search?q=ftw.tokenauth\n\n\nCopyright\n=========\n\nThis package is copyright by `4teamwork <http://www.4teamwork.ch/>`_.\n\n``ftw.tokenauth`` is licensed under GNU General Public License, version 2.\n\n\nChangelog\n=========\n\n\n1.2.0 (2023-12-13)\n------------------\n\n- Add fallback user lookup by username (login).\n [phgross]\n\n\n1.1.0 (2018-07-12)\n------------------\n\n- Allow to impersonate another user.\n [buchi]\n\n\n1.0.1 (2018-04-16)\n------------------\n\n- Switch to `ipaddress` module instead of `py2-ipaddress` for IP range\n parsing, and fix unicode handling.\n [lgraf]\n\n\n1.0.0 (2018-04-04)\n------------------\n\n- Initial implementation\n [lgraf]",
"bugtrack_url": null,
"license": "GPL2",
"summary": "Token Authentication for Plone",
"version": "1.2.0",
"project_urls": {
"Homepage": "https://github.com/4teamwork/ftw.tokenauth"
},
"split_keywords": [
"token",
"authentication",
"plone",
"oauth2",
"jwt"
],
"urls": [
{
"comment_text": "",
"digests": {
"blake2b_256": "9390b0cc87bf82dd11cf3cb6d01696153e29e2c533b101c1d8c5eff0f350daca",
"md5": "eea73d871d5da0bfb1cd07b98abb4d94",
"sha256": "fa87a686faed994a332d1d92722b042132a647a674630e6f90d73209d813a427"
},
"downloads": -1,
"filename": "ftw.tokenauth-1.2.0.tar.gz",
"has_sig": false,
"md5_digest": "eea73d871d5da0bfb1cd07b98abb4d94",
"packagetype": "sdist",
"python_version": "source",
"requires_python": null,
"size": 197196,
"upload_time": "2023-12-13T09:54:51",
"upload_time_iso_8601": "2023-12-13T09:54:51.276195Z",
"url": "https://files.pythonhosted.org/packages/93/90/b0cc87bf82dd11cf3cb6d01696153e29e2c533b101c1d8c5eff0f350daca/ftw.tokenauth-1.2.0.tar.gz",
"yanked": false,
"yanked_reason": null
}
],
"upload_time": "2023-12-13 09:54:51",
"github": true,
"gitlab": false,
"bitbucket": false,
"codeberg": false,
"github_user": "4teamwork",
"github_project": "ftw.tokenauth",
"travis_ci": false,
"coveralls": false,
"github_actions": false,
"lcname": "ftw.tokenauth"
}
JSON
