ckanext-saml2auth

A CKAN extension to enable Single Sign-On (SSO) for CKAN data portals via SAML2 Authentication.

Requirements

This extension works with CKAN 2.9+.

Installation

To install ckanext-saml2auth:

1. Install the required system packages:

   sudo apt install xmlsec1
   

2. Activate your CKAN virtual environment, for example:

   . /usr/lib/ckan/default/bin/activate
   

3. Install the required system packages to install the necessary python module dependencies:

   # rustc and cargo are neeeded to build cryptography if no binary wheel exists
   sudo apt install rustc cargo
   

4. Install the ckanext-saml2auth Python package into your virtual environment:

   pip install ckanext-saml2auth
   

5. Add saml2auth to the ckan.plugins setting in your CKAN config file (by default the config file is located at /etc/ckan/default/ckan.ini).

6. Restart CKAN. For example if you've deployed CKAN with Apache on Ubuntu:

   sudo service apache2 reload
   

Config settings

Required:

# Specifies the metadata location type
# Options: local or remote
ckanext.saml2auth.idp_metadata.location = remote

# Path to a local file accessible on the server the service runs on
# Ignore this config if the idp metadata location is set to: remote
ckanext.saml2auth.idp_metadata.local_path = /opt/metadata/idp.xml

# A remote URL serving aggregate metadata
# Ignore this config if the idp metadata location is set to: local
ckanext.saml2auth.idp_metadata.remote_url = https://kalmar2.org/simplesaml/module.php/aggregator/?id=kalmarcentral2&set=saml2

# Path to a local file accessible on the server the service runs on
# Ignore this config if the idp metadata location is set to: local and metadata is public
ckanext.saml2auth.idp_metadata.remote_cert = /opt/metadata/kalmar2.cert

# Corresponding SAML user field for firstname
ckanext.saml2auth.user_firstname = firstname

# Corresponding SAML user field for lastname
ckanext.saml2auth.user_lastname = lastname

# Corresponding SAML user field for fullname
# (Optional: Can be used as an alternative to firstname + lastname)
ckanext.saml2auth.user_fullname = fullname

# Corresponding SAML user field for email
ckanext.saml2auth.user_email = email

Optional:

# URL route of the endpoint where the SAML assertion is sent, also known as Assertion Consumer Service (ACS).
# Default: /acs
ckanext.saml2auth.acs_endpoint = /sso/post

# Configuration setting that enables CKAN's internal register/login functionality as well
# Default: False
ckanext.saml2auth.enable_ckan_internal_login = True

# List of email addresses from users that should be created as sysadmins (system administrators)
# Note that this means that CKAN sysadmins will _only_ be managed based on this config option and will override existing user permissions in the CKAN database
# If not set then it is ignored and CKAN sysadmins are managed through normal means
# Default: <Not set>
ckanext.saml2auth.sysadmins_list = mail@domain.com mail2@domain.com mail3@domain.com

# Indicates that attributes that are not recognized (they are not configured in attribute-mapping),
# will not be discarded.
# Default: True
ckanext.saml2auth.allow_unknown_attributes = False

# A list of string values that will be used to set the <NameIDFormat> element of the metadata of an entity.
# Default: urn:oasis:names:tc:SAML:2.0:nameid-format:persistent
ckanext.saml2auth.sp.name_id_format = urn:oasis:names:tc:SAML:2.0:nameid-format:persistent urn:oasis:names:tc:SAML:2.0:nameid-format:transient

# A string value that will be used to set the Format attribute of the <NameIDPolicy> element of the metadata of an entity.
# Default: <Not set>
ckanext.saml2auth.sp.name_id_policy_format = urn:oasis:names:tc:SAML:2.0:nameid-format:persistent

# Entity ID (also know as Issuer)
# Define the entity ID. Default is urn:mace:umu.se:saml:ckan:sp
ckanext.saml2auth.entity_id = urn:gov:gsa:SAML:2.0.profiles:sp:sso:gsa:catalog-dev

# Signed responses and assertions
ckanext.saml2auth.want_response_signed = True
ckanext.saml2auth.want_assertions_signed = False
ckanext.saml2auth.want_assertions_or_response_signed = False

# Cert & key files
ckanext.saml2auth.key_file_path = /path/to/mykey.pem
ckanext.saml2auth.cert_file_path = /path/to/mycert.pem

# Attribute map directory
ckanext.saml2auth.attribute_map_dir = /path/to/dir/attributemaps

# Authentication context request before redirect to login
# e.g. to ask for a PIV card with login.gov provider (https://developers.login.gov/oidc/#aal-values) use:
ckanext.saml2auth.requested_authn_context = http://idmanagement.gov/ns/assurance/aal/3?hspd12=true
# You can use multiple context separated by spaces
ckanext.saml2auth.requested_authn_context = req1 req2

# Define the comparison value for RequestedAuthnContext
# Comparison could be one of this: exact, minimum, maximum or better
ckanext.saml2auth.requested_authn_context_comparison = exact

# Indicates if this entity will sign the Logout Requests originated from it
ckanext.saml2auth.logout_requests_signed = False

# Saml logout request preferred binding settings variable
# Default: urn:oasis:names:tc:SAML:2.0:bindings:HTTP-POST
ckanext.saml2auth.logout_expected_binding =  urn:oasis:names:tc:SAML:2.0:bindings:HTTP-POST

# Default fallback endpoint to redirect to if no RelayState provided in the SAML Response
# Default: user.me (ie /dashboard)
# e.g. to redirect to the home page
ckanext.saml2auth.default_fallback_endpoint = home.index

Plugin interface

This extension provides the [ISaml2Auth]{.title-ref} interface that allows other plugins to hook into the Saml2 authorization flow. This allows plugins to integrate custom logic like:

• Include additional attributes returned via the IdP as [plugin_extras]{.title-ref} in the CKAN users
• Assign users to specific organizations with specific roles based on Saml2 attributes
• Customize the flow response, to eg issue redirects or include custom headers.

For a list of available methods and their parameters check the ckanext/saml2auth/interfaces.py file, and for a basic example see the ExampleISaml2AuthPlugin class.

Developer installation

To install ckanext-saml2auth for development, activate your CKAN virtualenv and do:

sudo apt install xmlsec1
git clone https://github.com/duskobogdanovski/ckanext-saml2auth.git
cd ckanext-saml2auth
python setup.py develop
pip install -r dev-requirements.txt

Tests

To run the tests, do:

pytest --ckan-ini=test.ini

To run the tests and produce a coverage report, first make sure you have pytest-cov installed in your virtualenv (pip install pytest-cov) then run:

pytest --ckan-ini=test.ini  --cov=ckanext.saml2auth

Releasing a new version of ckanext-saml2auth

ckanext-saml2auth should be available on PyPI as https://pypi.org/project/ckanext-saml2auth. To publish a new version to PyPI follow these steps:

1. Update the version number in the setup.py file. See PEP 440 for how to choose version numbers.

2. Make sure you have the latest version of necessary packages:

   pip install --upgrade setuptools wheel twine
   

3. Create a source and binary distributions of the new version:

   python setup.py sdist bdist_wheel && twine check dist/*
   

   Fix any errors you get.

4. Upload the source distribution to PyPI:

   twine upload dist/*
   

5. Commit any outstanding changes:

   git commit -a
   git push
   

6. Tag the new release of the project on GitHub with the version number from the setup.py file. For example if the version number in setup.py is 0.0.1 then do:

   git tag 0.0.1
   git push --tags