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djangosaml2idp

PyPi Python Django Documentation Status Apache 2.0 License

djangosaml2idp implements the Identity Provider side of the SAML2 protocol for Django. It builds on top of PySAML2, and is production-ready.

Package version 0.3.3 was the last Python 2 / Django 1.8-1.11 compatible release. Versions starting from 0.4.0 are for Python 3 and Django 2.x.

Any contributions, feature requests, proposals, ideas ... are welcome! See the CONTRIBUTING document for some info.

Installation

PySAML2 uses XML Security Library binary to sign SAML assertions, so you need to install it either through your operating system package or by compiling the source code. It doesn't matter where the final executable is installed because you will need to set the full path to it in the configuration stage. XmlSec is available (at least) for Debian, OSX and Alpine Linux.

Now you can install the djangosaml2idp package using pip. This will also install PySAML2 and its dependencies automatically:

pip install djangosaml2idp

Configuration & Usage

The first thing you need to do is add djangosaml2idp to the list of installed apps:

INSTALLED_APPS = (
    'django.contrib.admin',
    'djangosaml2idp',
    ...
)

Now include djangosaml2idp in your project by adding it in the url config:

from django.conf.urls import url, include
from django.contrib import admin

urlpatterns = [
    url(r'^idp/', include('djangosaml2idp.urls')),
    url(r'^admin/', admin.site.urls),
    ...
]

In your Django settings, configure your IdP. Configuration follows the PySAML2 configuration. The IdP from the example project looks like this:

...
import saml2
from saml2.saml import NAMEID_FORMAT_EMAILADDRESS, NAMEID_FORMAT_UNSPECIFIED
from saml2.sigver import get_xmlsec_binary

LOGIN_URL = '/login/'
BASE_URL = 'http://localhost:9000/idp'

SAML_IDP_CONFIG = {
    'debug' : DEBUG,
    'xmlsec_binary': get_xmlsec_binary(['/opt/local/bin', '/usr/bin/xmlsec1']),
    'entityid': '%s/metadata' % BASE_URL,
    'description': 'Example IdP setup',

    'service': {
        'idp': {
            'name': 'Django localhost IdP',
            'endpoints': {
                'single_sign_on_service': [
                    ('%s/sso/post' % BASE_URL, saml2.BINDING_HTTP_POST),
                    ('%s/sso/redirect' % BASE_URL, saml2.BINDING_HTTP_REDIRECT),
                ],
            },
            'name_id_format': [NAMEID_FORMAT_EMAILADDRESS, NAMEID_FORMAT_UNSPECIFIED],
            'sign_response': True,
            'sign_assertion': True,
        },
    },

    'metadata': {
        'local': [os.path.join(os.path.join(os.path.join(BASE_DIR, 'idp'), 'saml2_config'), 'sp_metadata.xml')],
    },
    # Signing
    'key_file': BASE_DIR + '/certificates/private.key',
    'cert_file': BASE_DIR + '/certificates/public.cert',
    # Encryption
    'encryption_keypairs': [{
        'key_file': BASE_DIR + '/certificates/private.key',
        'cert_file': BASE_DIR + '/certificates/public.cert',
    }],
    'valid_for': 365 * 24,
}

Notice the configuration requires a private key and public certificate to be available on the filesystem in order to sign and encrypt messages.

You also have to define a mapping for each SP you talk to. An example SP config:

...
SAML_IDP_SPCONFIG = {
    'http://localhost:8000/saml2/metadata/': {
        'processor': 'djangosaml2idp.processors.BaseProcessor',
        'nameid_field': 'staffID'
        'sign_response': False,
        'sign_assertion': False,
        'attribute_mapping': {
            # DJANGO: SAML
            'email': 'email',
            'first_name': 'first_name',
            'last_name': 'last_name',
            'is_staff': 'is_staff',
            'is_superuser':  'is_superuser',
            'method_to_get_id': 'id',
        }
    },
    'bare_minimum_config': {}
}

Please note that the only required field for each SP is the Entity ID, which is the key for each individual SP config dict. The bare minimum is setting SAML_IDP_CONFIG[Your Entity Id] = {}. Also, attribute_mapping will default to {'username': 'username'}. If you would like to not send any attributes to the SP, set attribute_mapping to an empty dict ({}). You can provide methods instead of attributes from the Django side in the attribute mapping. Just make sure that the method only accepts 1 parameter (self), and that you don't put parentheses in the attribute mapping.

If you want to override sign_assertion and/or sign_response for individual SPs, you can do so in SAML_IDP_SPCONFIG, as seen above. If unset, these will default to the values set in SAML_IDP_CONFIG.

The last step is configuring metadata. Download a copy of the IdP's metadata from <YOUR_SERVER_URL>/idp/metadata (assuming that's how you set up your urls.py). Use it to configure your SPs as required by them. Obtain a copy of the metadata for each of your SPs, and upload them where you indicated in SAML_IDP_CONFIG['metadata]

Further optional configuration options

In the SAML_IDP_SPCONFIG setting you can define a processor, its value being a string with dotted path to a class. This is a hook to customize some access control checks. By default, the included BaseProcessor is used, which allows every user to login on the IdP. You can customize this behaviour by subclassing the BaseProcessor and overriding its has_access(self, request) method. This method should return true or false, depending if the user has permission to log in for the SP / IdP. The processor has the SP entity ID available as self._entity_id, and received the request (with an authenticated request.user on it) as parameter to the has_access function. This way, you should have the necessary flexibility to perform whatever checks you need. An example processor subclass can be found in the IdP of the included example. Use this metadata xml to configure your SP. Place the metadata xml from that SP in the location specified in the config dict (sp_metadata.xml in the example above).

Without custom setting, users will be identified by the USERNAME_FIELD property on the user Model you use. By Django defaults this will be the username. You can customize which field is used for the identifier by adding SAML_IDP_DJANGO_USERNAME_FIELD to your settings with as value the attribute to use on your user instance. You can also override this per SP by setting nameid_field in the SP config, as seen in the sample SAML_IDP_SPCONFIG above.

Customizing error handling

djangosaml2idp renders a very basic error page if it encounters an error, indicating an error occured, which error, and possibly an extra message. The HTTP status code is also set if possible depending on which error occured. You can customize this by using the SAML_IDP_ERROR_VIEW_CLASS setting. Set this to a dotted import path to your custom (class based) view in order to use that one. If you subclass the provided djangosaml2idp.error_views.SamlIDPErrorView, you have the following variables available for use in the template:

exception_type
the class of the exception that occurred
exception_msg
the message from the exception (by doing str(exception))
extra_message
if no specific exception given, a message indicating something went wrong, or an additional message next to the exception_msg

The simplest override is to subclass the SamlIDPErrorView and only using your own error template. You can use any Class-Based-View for this; it's not necessary to subclass the builtin error view. The example project contains a ready to use example of this; uncomment the SAML_IDP_ERROR_VIEW_CLASS setting and it will use a custom view with custom template.

Multi Factor Authentication support

There are three main components to adding multiple factor support.

  1. Subclass djangosaml2idp.processors.BaseProcessor as outlined above. You will need to override the enable_multifactor() method to check whether or not multifactor should be enabled for a user. (If it should allways be enabled for all users simply hard code to True). By default it unconditionally returns False and no multifactor is enforced.
  2. Sublass the djangosaml2idp.views.ProcessMultiFactorView view to make the appropriate calls for your environment. Implement your custom verification logic in the multifactor_is_valid method: this could call a helper script, an internal SMS triggering service, a data source only the IdP can access or an external second factor provider (e.g. Symantec VIP). By default this view will log that it was called then redirect.
  3. Update your urls.py and add an override for name='saml_multi_factor' - ensure it comes before importing the djangosaml2idp urls file so your custom view is used instead of the built-in one.

Running the test suite

Install the dev dependencies in requirements-dev.txt:

pip install -r requirements-dev.txt

Run py.test from the project root:

py.test

Example project

The directory example_project contains a barebone demo setup to demonstrate the login-logout functionality. It consists of a Service Provider implemented with djangosaml2 and an Identity Provider using djangosaml2idp. The readme in that folder contains more information on how to run it.