simplesamlphp-module-oidc

A SimpleSAMLphp module for OIDC OP support.

This module adds support for OpenID Provider role from the OpenID Connect protocol through a SimpleSAMLphp module installable through Composer. It is based on Oauth2 Server from the PHP League

Currently supported flows are:

• Authorization Code flow, with PKCE support (response_type 'code')
• Implicit flow (response_type 'id_token token' or 'id_token')
• Plain OAuth2 Implicit flow (response_type 'token')
• Refresh Token flow

Version compatibility

Minor versions of SimpleSAMLphp noted below means that the module has been tested with that version of SimpleSAMLphp during module development. SimpleSAMLphp started following semantic versioning for its API from version 2.0. This means, for example, that v5.* of the oidc module should work on any v2.* of SimpleSAMLphp. However, do mind that there were PHP version requirement changes in minor releases for SimpleSAMLphp.

OIDC module	Tested SimpleSAMLphp	PHP	Note
v5.*	v2.1.*	>=8.1	Recommended
v4.*	v2.0.*	>=8.0
v3.*	v2.0.*	>=7.4	Abandoned from August 2023.
v2.*	v1.19.*	>=7.4

Upgrading?

If you are upgrading from a previous version, checkout the upgrade guide.

Installation

Installation can be as easy as executing:

composer require simplesamlphp/simplesamlphp-module-oidc

Configure the module

Copy the module config template file to the SimpleSAMLphp config directory:

cp modules/oidc/config-templates/module_oidc.php config/

The options are self-explanatory, so make sure to go through the file and edit them as appropriate.

Configure the database

This module uses a default SimpleSAMLphp database feature to store access/refresh tokens, user data, etc. In order for this to work, edit your config/config.php and check 'database' related configuration. Make sure you have at least the following parameters set:

'database.dsn' => 'mysql:host=server;dbname=simplesamlphp;charset=utf8',
'database.username' => 'user',
'database.password' => 'password',

Create RSA key pair

During the authentication flow, generated ID Token and Access Token will be in a form of signed JSON Web token (JWS). Because of the signing part, you need to create a public/private RSA key pair.

To generate the private key, you can run this command in the terminal:

openssl genrsa -out cert/oidc_module.key 3072

If you want to provide a passphrase for your private key, run this command instead:

openssl genrsa -passout pass:myPassPhrase -out cert/oidc_module.key 3072

Now you need to extract the public key from the private key:

openssl rsa -in cert/oidc_module.key -pubout -out cert/oidc_module.crt

or use your passphrase if provided on private key generation:

openssl rsa -in cert/oidc_module.key -passin pass:myPassPhrase -pubout -out cert/oidc_module.crt

If you use a passphrase, make sure to also configure it in the module_oidc.php config file.

Enabling the module

At this point we can enable the module by adding 'oidc' => true to the list of enabled modules in the main simplesamlphp configuration file, config/config.php.

'module.enable' => [
    'exampleauth' => false,
    'core' => true,
    'admin' => true,
    'saml' => true,
    // enable oidc module
    'oidc' => true
],

This is required the enable the module on the Federation tab in the admin web interface, which can be used in the next two steps to finalize the installation.

Run database migrations

The module comes with some default SQL migrations which set up needed tables in the configured database. To run them, open the Federation tab from your SimpleSAMLphp installation and select the option OpenID Connect Installation inside the Tools section. Once there, all you need to do is press the Install button and the schema will be created.

Alternatively, in case of automatic / scripted deployments, you can run the 'install.php' script from the command line:

php modules/oidc/bin/install.php

Relying Party (RP) Administration

The module lets you manage (create, read, update and delete) approved RPs from the module user interface itself.

Once the database schema has been created, you can open the Federation tab from your SimpleSAMLphp installation and select the option OpenID Connect Client Registry inside the Tools section.

Note that clients can be marked as confidential or public. If the client is not marked as confidential (it is public), and is using Authorization Code flow, it will have to provide PKCE parameters during the flow.

Client ID and secret will be generated, and can be seen after the client creation by clicking on the 'show' button.

Cron hook

In order to purge expired tokens, this module requires cron module to be enabled and configured.

Endpoint locations

Once you deployed the module, you will need the exact endpoint urls the module provides to configure the relying parties. You can visit the discovery endpoint to learn this information:

<basepath>/module.php/oidc/openid-configuration.php

This endpoint can be used to set up a .well-known URL (see below).

Additional considerations

Private scopes

This module support the basic OIDC scopes: openid, email, address, phone and profile. However, you can add your own private scopes in the module_oidc.php config file, for example:

<?php

$config = [
    \SimpleSAML\Module\oidc\ModuleConfig::OPTION_AUTH_CUSTOM_SCOPES => [
        'private' => [
            'description' => 'private scope',
            'claim_name_prefix' => '', // Optional prefix for claim names
            'are_multiple_claim_values_allowed' => false, // Allow or disallow multiple values for claims
            'attributes' => ['national_document_id']
        ],
    ],
];

Attribute translation

Default translation table from SAML attributes to OIDC claims is based on REFEDS wiki article: "Mapping SAML attributes to OIDC Claims".

You can change or extend this table in the module_oidc.php config file, for example:

<?php

$config = [
    \SimpleSAML\Module\oidc\ModuleConfig::OPTION_AUTH_SAML_TO_OIDC_TRANSLATE_TABLE => [
        // Overwrite default translation
        'sub' => [
            'uid', // added
            'eduPersonPrincipalName',
            'eduPersonTargetedID',
            'eduPersonUniqueId',
        ],
        // Remove default translation
        'family_name' => [
        ],

        // New claim created from SAML attribute
        // Used in previus private scope
        'national_document_id' => [
            'schacPersonalUniqueId',
        ],
    ],
];

Auth Proc Filters

This module will not execute standard Auth Proc Filters which are used during regular SAML authN, reason being that not all expected entities are participating in the authN process (most notably the Service Provider - SP). Because of that, OIDC module provides its own 'authproc.oidc' configuration option which can be used to designate specific Auth Proc Filters which will run only during OIDC authN.

However, there are some considerations. OIDC authN state array will not contain all the keys which are available during SAML authN, like Service Provider metadata. If you are using an existing filter, make sure it does not rely on some non-existent state data. At the moment, only the following SAML authN data will be available:

• ['Attributes']
• ['Authority']
• ['AuthnInstant']
• ['Expire']

Source and destination will have entity IDs corresponding to the OP issuer ID and Client ID respectively.

• ['Source']['entityid'] - contains OpenId Provider issuer ID
• ['Destination']['entityid'] - contains Relying Party (OIDC Client) ID

In addition to that, the following OIDC related data will be available in the state array:

• ['Oidc']['OpenIdProviderMetadata'] - contains information otherwise available from the OIDC configuration URL.
• ['Oidc']['RelyingPartyMetadata'] - contains information about the OIDC client making the authN request.
• ['Oidc']['AuthorizationRequestParameters'] - contains relevant authorization request query parameters.

Note: at the moment there is no support for showing a page to the user in a filter, and then resuming the filtering. Only the common filter use cases are supported like attribute handling, logging, or similar.

You can add Auth Proc filters in the 'authproc.oidc' config option in the same manner as described in the Auth Proc documentation.

<?php

$config = [
    \SimpleSAML\Module\oidc\ModuleConfig::OPTION_AUTH_PROCESSING_FILTERS => [
        50 => [
            'class' => 'core:AttributeAdd',
            'groups' => ['users', 'members'],
        ],
    ],
];

Client registration permissions

You can allow users to register their own clients. This is controlled through the permissions setting in module_oidc.php

Permissions let the module expose functionality to specific users. In the below configuration, a user's eduPersonEntitlement attribute is examined. If the user tries to do something that requires the client permission (such as registering their own client) then they will need one of the eduPersonEntitlements from the client permission array.

A permission can be disabled by commenting it out.

     \SimpleSAML\Module\oidc\ModuleConfig::OPTION_ADMIN_UI_PERMISSIONS => [
        // Attribute to inspect to determine user's permissions
        'attribute' => 'eduPersonEntitlement',
        // Which entitlements allow for registering, editing, delete a client. OIDC clients are owned by the creator
        'client' => ['urn:example:oidc:manage:client'],
    ],

Users can visit the https://example.com/simplesaml/module.php/oidc/clients/ to create and view their clients.

OIDC Discovery

The module offers an OpenID Connect Discovery endpoint at URL:

https://yourserver/simplesaml/module.php/oidc/openid-configuration.php

.well-known URL

You can configure you web server (Apache, Nginx) in a way to serve the mentioned autodiscovery URL in a '.well-known' form. Here are some sample configurations:

nginx

location = /.well-known/openid-configuration {
    rewrite ^(.*)$ /simplesaml/module.php/oidc/openid-configuration.php break;
    proxy_pass https://localhost;
}

Apache

Alias /.well-known/openid-configuration "/path/to/simplesamlphp/module.php/oidc/openid-configuration.php"

Using Docker

With current git branch.

To explore the module using docker run the below command. This will run an SSP image, with the current oidc module mounted in the container, along with some configuration files. Any code changes you make to your git checkout are "live" in the container, allowing you to test and iterate different things.

docker run --name ssp-oidc-dev \
   --mount type=bind,source="$(pwd)",target=/var/simplesamlphp/staging-modules/oidc,readonly \
  -e STAGINGCOMPOSERREPOS=oidc \
  -e COMPOSER_REQUIRE="simplesamlphp/simplesamlphp-module-oidc:@dev" \
  -e SSP_ADMIN_PASSWORD=secret1 \
  --mount type=bind,source="$(pwd)/docker/ssp/module_oidc.php",target=/var/simplesamlphp/config/module_oidc.php,readonly \
  --mount type=bind,source="$(pwd)/docker/ssp/authsources.php",target=/var/simplesamlphp/config/authsources.php,readonly \
  --mount type=bind,source="$(pwd)/docker/ssp/config-override.php",target=/var/simplesamlphp/config/config-override.php,readonly \
  --mount type=bind,source="$(pwd)/docker/ssp/oidc_module.crt",target=/var/simplesamlphp/cert/oidc_module.crt,readonly \
  --mount type=bind,source="$(pwd)/docker/ssp/oidc_module.key",target=/var/simplesamlphp/cert/oidc_module.key,readonly \
  --mount type=bind,source="$(pwd)/docker/apache-override.cf",target=/etc/apache2/sites-enabled/ssp-override.cf,readonly \
   -p 443:443 cirrusid/simplesamlphp:v2.2.2

Visit https://localhost/simplesaml/ and confirm you get the default page. Then navigate to OIDC screen and you can add a client.

You may view the OIDC configuration endpoint at https://localhost/.well-known/openid-configuration

Build Image to Deploy for Conformance Tests

Build an image that contains a pre-configured sqlite database.

GIT_BRANCH=$(git rev-parse --abbrev-ref HEAD)
# Replace invalid tag characters when doing build
IMAGE_TAG=$(tr '/' '_' <<< $GIT_BRANCH)
docker build -t "simplesamlphp/simplesamlphp-oidc:dev-$IMAGE_TAG" \
  --build-arg OIDC_VERSION=dev-${GIT_BRANCH} \
  -f docker/Dockerfile .

docker run --name ssp-oidc-dev-image \
  -e SSP_ADMIN_PASSWORD=secret1 \
  -p 443:443 simplesamlphp/simplesamlphp-oidc:dev-$IMAGE_TAG

Publish the image somewhere you can retrieve it. Temporarily, this will occasionally get published into the cirrusid Docker namespace.

docker tag "simplesamlphp/simplesamlphp-oidc:dev-$IMAGE_TAG" "cirrusid/simplesamlphp-oidc:dev-$IMAGE_TAG"
docker push "cirrusid/simplesamlphp-oidc:dev-$IMAGE_TAG"

The database is not currently on a share volume, so any changes will get lost if the container restarts. You may want to back it up. To dump the database

docker exec ssp-oidc-dev-image sqlite3  /var/simplesamlphp/data/mydb.sq3 '.dump' > docker/conformance.sql

Conformance tests are easier to run locally, see the Docker compose section and CONFORMANCE_TEST.md

Docker compose

Docker compose will run several containers to make it easier to test scenarios. It will build an image that contains OIDC module. You may remove the --build argument if you want docker-compose to reuse previously running container.

# Use the current branch/git checkout. Composer installs local checkout
OIDC_VERSION=@dev docker-compose -f docker/docker-compose.yml --project-directory . up --build

# Set OIDC_VERSION to a version that composer can install to use a different version of the module.
OIDC_VERSION=dev-master docker-compose -f docker/docker-compose.yml --project-directory . up --build

Visit the OP and confirm a few clients already exist.

Conformance tests are easier to run locally, see CONFORMANCE_TEST.md

Running Conformance Tests

See CONFORMANCE_TEST.md

Have more questions?

Check the FAQ.