keystone/doc/source/federation/shibboleth.rst
Colleen Murphy 38f79a8edf Update, correct, and enhance federation docs
This patch updates and adds examples and clarifies some instructions
that were unclear or needed additional explanation for the Federation
configuration overview, the Shibboleth setup instructions, and the
horizon WebSSO documentation. These changes include:

 - Change instances of 'saml2' to 'mapped' where appropriate, since the
   documentation currently notes that using 'saml2' is deprecated
 - Make note of differences when using keystone-to-keystone federation
   and keystone as an Identity Provider where appropriate
 - Linkify section contents listings
 - Add examples using openstackclient
     - The examples include adding both a domain and a project for
       federated users, since there seems to be a horizon bug that
       cause federated users to not be able to log in if their group is
       only authorized on a domain and no projects[1] (not yet filed)
 - Move discussion of remote IDs from the websso section to the main
   configuration section, since the instructions to add identity
   providers are already in the main section and this is really more
   about keystone configuration than horizon configuration
 - Add example mapping rules for both a keystone-to-keystone
   configuration and a Shibboleth (using testshib.org) configuration
 - Correct description of token response format in "Performing
   federated authentication" section
 - Enhance description of configuration options for keystone as an IdP
 - Make the names and domain names of Service Providers and Identity
   Providers consistent throughout the documentation (beta and BETA
   were especially confusing)
 - Change references to wsgi-keystone.conf to keystone.conf since
   that's what devstack calls it now
 - Change keystone-to-keystone authentication demo to use keystoneauth
   instead of cURL (inspired by rodrigods's blog post on
   keystone-to-keystone[2])
 - Move the note about fetching the SP's metadata to after
   shibboleth2.xml configuration is done, since the entityID needs to
   be set in the metadata for the IdP to recognize it
 - Enhance the description of what needs to be changed in
   shibboleth2.xml and use the package-generated example
 - Remove the section on removing REMOTE_USER from shibboleth2.xml, as
   this is needed to allow keystone to look up the remote user in the
   SAML assertion
 - Remove sections about keystone v3 from the WebSSO, that's old news
   and it's the default now
 - Add a step to ensure the SSO redirect template is copied into place,
   since devstack does not do that by default

[1] http://git.openstack.org/cgit/openstack/django_openstack_auth/tree/openstack_auth/backend.py?h=2.4.1#n174
[2] http://blog.rodrigods.com/it-is-time-to-play-with-keystone-to-keystone-federation-in-kilo/

Change-Id: Id3ad18c43ace9e43d05b0acf966e577c909fa3e8
2016-10-14 20:33:25 +02:00

12 KiB

Setup Shibboleth

Configure Apache HTTPD for mod_shibboleth

Follow the steps outlined at: Running Keystone in HTTPD.

You'll also need to install Shibboleth, for example:

$ apt-get install libapache2-mod-shib2

Configure your Keystone virtual host and adjust the config to properly handle SAML2 workflow:

Add WSGIScriptAlias directive to your vhost configuration:

WSGIScriptAliasMatch ^(/v3/OS-FEDERATION/identity_providers/.*?/protocols/.*?/auth)$ /var/www/keystone/main/$1

Make sure the keystone.conf vhost file contains a <Location> directive for the Shibboleth module and a <Location> directive for each identity provider:

<Location /Shibboleth.sso>
    SetHandler shib
</Location>

<Location /v3/OS-FEDERATION/identity_providers/myidp/protocols/mapped/auth>
    ShibRequestSetting requireSession 1
    AuthType shibboleth
    ShibExportAssertion Off
    Require valid-user

    <IfVersion < 2.4>
        ShibRequireSession On
        ShibRequireAll On
   </IfVersion>
</Location>

Note

* mapped is the name of the protocol that you will configure * myidp is the name associated with the IdP in Keystone * The ShibRequireSession and ShibRequireAll rules are invalid in Apache 2.4+. * You are advised to carefully examine Shibboleth Apache configuration documentation

Enable the shib2 module, for example:

$ a2enmod shib2

Restart Apache, for example:

$ service apache2 restart

Configuring shibboleth2.xml

Once you have your Keystone vhost (virtual host) ready, it's then time to configure Shibboleth and upload your Metadata to the Identity Provider.

Create a new keypair for Shibboleth with:

$ shib-keygen -y <number of years>

The newly created key file will be stored under /etc/shibboleth/sp-key.pem.

Configure your Service Provider by editing /etc/shibboleth/shibboleth2.xml file. You will want to change five settings:

  • Set the SP entity ID. This value usually has the form of a URI but it does not have to resolve to anything. It must uniquely identify your Service Provider to your Identity Provider.
<ApplicationDefaults entityID="http://mysp.example.com/shibboleth">

* Set the IdP entity ID. This value is determined by the IdP. For example, if Keystone is the IdP:

<SSO entityID="https://myidp.example.com/v3/OS-FEDERATION/saml2/idp">

Example if testshib.org is the IdP:

<SSO entityID="https://idp.testshib.org/idp/shibboleth">
  • Remove the discoveryURL lines unless you want to enable advanced IdP discovery.
  • Add a MetadataProvider block. The URI given here is a real URL that Shibboleth will use to fetch metadata from the IdP. For example, if Keystone is the IdP:
<MetadataProvider type="XML" uri="https://myidp.example.com:5000/v3/OS-FEDERATION/saml2/metadata"/>

Example if testshib.org is the IdP:

<MetadataProvider type="XML" uri="http://www.testshib.org/metadata/testshib-providers.xml" />

You are advised to examine Shibboleth Service Provider Configuration documentation

The result should look like (The example shown below is for reference only, not to be used in a production environment):

<SPConfig xmlns="urn:mace:shibboleth:2.0:native:sp:config"
    xmlns:conf="urn:mace:shibboleth:2.0:native:sp:config"
    xmlns:saml="urn:oasis:names:tc:SAML:2.0:assertion"
    xmlns:samlp="urn:oasis:names:tc:SAML:2.0:protocol"
    xmlns:md="urn:oasis:names:tc:SAML:2.0:metadata"
    clockSkew="180">

    <!--
    By default, in-memory StorageService, ReplayCache, ArtifactMap, and SessionCache
    are used. See example-shibboleth2.xml for samples of explicitly configuring them.
    -->

    <!--
    To customize behavior for specific resources on Apache, and to link vhosts or
    resources to ApplicationOverride settings below, use web server options/commands.
    See https://wiki.shibboleth.net/confluence/display/SHIB2/NativeSPConfigurationElements for help.

    For examples with the RequestMap XML syntax instead, see the example-shibboleth2.xml
    file, and the https://wiki.shibboleth.net/confluence/display/SHIB2/NativeSPRequestMapHowTo topic.
    -->

    <!-- The ApplicationDefaults element is where most of Shibboleth's SAML bits are defined. -->
    <ApplicationDefaults entityID="https://mysp.example.com/shibboleth">

        <!--
        Controls session lifetimes, address checks, cookie handling, and the protocol handlers.
        You MUST supply an effectively unique handlerURL value for each of your applications.
        The value defaults to /Shibboleth.sso, and should be a relative path, with the SP computing
        a relative value based on the virtual host. Using handlerSSL="true", the default, will force
        the protocol to be https. You should also set cookieProps to "https" for SSL-only sites.
        Note that while we default checkAddress to "false", this has a negative impact on the
        security of your site. Stealing sessions via cookie theft is much easier with this disabled.
        -->
        <Sessions lifetime="28800" timeout="3600" relayState="ss:mem"
                  checkAddress="false" handlerSSL="false" cookieProps="http">

            <!--
            Configures SSO for a default IdP. To allow for >1 IdP, remove
            entityID property and adjust discoveryURL to point to discovery service.
            (Set discoveryProtocol to "WAYF" for legacy Shibboleth WAYF support.)
            You can also override entityID on /Login query string, or in RequestMap/htaccess.
            -->
            <SSO entityID="https://myidp.example.com/v3/OS-FEDERATION/saml2/idp">
              SAML2 SAML1
            </SSO>

            <!-- SAML and local-only logout. -->
            <Logout>SAML2 Local</Logout>

            <!-- Extension service that generates "approximate" metadata based on SP configuration. -->
            <Handler type="MetadataGenerator" Location="/Metadata" signing="false"/>

            <!-- Status reporting service. -->
            <Handler type="Status" Location="/Status" acl="127.0.0.1 ::1"/>

            <!-- Session diagnostic service. -->
            <Handler type="Session" Location="/Session" showAttributeValues="false"/>

            <!-- JSON feed of discovery information. -->
            <Handler type="DiscoveryFeed" Location="/DiscoFeed"/>
        </Sessions>
        <!--
        Allows overriding of error template information/filenames. You can
        also add attributes with values that can be plugged into the templates.
        -->
        <Errors supportContact="root@localhost"
            helpLocation="/about.html"
            styleSheet="/shibboleth-sp/main.css"/>

        <!-- Example of remotely supplied batch of signed metadata. -->
        <!--
        <MetadataProvider type="XML" uri="http://federation.org/federation-metadata.xml"
              backingFilePath="federation-metadata.xml" reloadInterval="7200">
            <MetadataFilter type="RequireValidUntil" maxValidityInterval="2419200"/>
            <MetadataFilter type="Signature" certificate="fedsigner.pem"/>
        </MetadataProvider>
        -->

        <!-- Example of locally maintained metadata. -->
        <!--
        <MetadataProvider type="XML" file="partner-metadata.xml"/>
        -->
        <MetadataProvider type="XML" uri="https://myidp.example.com:5000/v3/OS-FEDERATION/saml2/metadata"/>

        <!-- Map to extract attributes from SAML assertions. -->
        <AttributeExtractor type="XML" validate="true" reloadChanges="false" path="attribute-map.xml"/>

        <!-- Use a SAML query if no attributes are supplied during SSO. -->
        <AttributeResolver type="Query" subjectMatch="true"/>

        <!-- Default filtering policy for recognized attributes, lets other data pass. -->
        <AttributeFilter type="XML" validate="true" path="attribute-policy.xml"/>

        <!-- Simple file-based resolver for using a single keypair. -->
        <CredentialResolver type="File" key="sp-key.pem" certificate="sp-cert.pem"/>

        <!--
        The default settings can be overridden by creating ApplicationOverride elements (see
        the https://wiki.shibboleth.net/confluence/display/SHIB2/NativeSPApplicationOverride topic).
        Resource requests are mapped by web server commands, or the RequestMapper, to an
        applicationId setting.
        Example of a second application (for a second vhost) that has a different entityID.
        Resources on the vhost would map to an applicationId of "admin":
        -->
        <!--
        <ApplicationOverride id="admin" entityID="https://admin.example.org/shibboleth"/>
        -->
    </ApplicationDefaults>

    <!-- Policies that determine how to process and authenticate runtime messages. -->
    <SecurityPolicyProvider type="XML" validate="true" path="security-policy.xml"/>

    <!-- Low-level configuration about protocols and bindings available for use. -->
    <ProtocolProvider type="XML" validate="true" reloadChanges="false" path="protocols.xml"/>

</SPConfig>

If keystone is your IdP, you will need to examine your attributes map file /etc/shibboleth/attribute-map.xml and add the following attributes:

<Attribute name="openstack_user" id="openstack_user"/>
<Attribute name="openstack_roles" id="openstack_roles"/>
<Attribute name="openstack_project" id="openstack_project"/>
<Attribute name="openstack_user_domain" id="openstack_user_domain"/>
<Attribute name="openstack_project_domain" id="openstack_project_domain"/>

For more information see the attributes documentation

Once you are done, restart your Shibboleth daemon and apache:

$ service shibd restart
$ service apache2 restart

Check /var/log/shibboleth/shibd_warn.log for any ERROR or CRIT notices and correct them.

Upload your Service Provider's metadata file to your Identity Provider. You can fetch it with:

$ wget http://mysp.example.com/Shibboleth.sso/Metadata

This step depends on your Identity Provider choice and is not covered here. If keystone is your Identity Provider you do not need to upload this file.