SAML V2.0 Metadata Attribute Extensions
=======================================
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This is a reference for the SimpleSAMLphp implementation of the [SAML
V2.0 Attribute Extensions](http://docs.oasis-open.org/security/saml/Post2.0/sstc-saml-attribute-ext.pdf)
defined by OASIS. A common use case is adding entity attributes
to the generated metadata.
For an IdP `metadata/saml20-idp-hosted.php` entries are used to define the
metadata extension items; for an SP they can be added to `config/authsources.php`.
An example of this is:
<?php
$metadata['entity-id-1'] = [
/* ... */
'EntityAttributes' => [
'urn:simplesamlphp:v1:simplesamlphp' => ['is', 'really', 'cool'],
'{urn:simplesamlphp:v1}foo' => ['bar'],
],
/* ... */
];
The OASIS specification primarily defines how to include arbitrary
`Attribute` and `Assertion` elements within the metadata for an entity.
*Note*: SimpleSAMLphp does not support `Assertion` elements within the
metadata at this time.
Defining Attributes
-------------------
The `EntityAttributes` key is used to define the attributes in the
metadata. Each item in the `EntityAttributes` array defines a new
`<Attribute>` item in the metadata. The value for each key must be an
array. Each item in this array produces a separte `<AttributeValue>`
element within the `<Attribute>` element.
'EntityAttributes' => [
'urn:simplesamlphp:v1:simplesamlphp' => ['is', 'really', 'cool'],
],
This generates:
<saml:Attribute xmlns:saml="urn:oasis:names:tc:SAML:2.0:assertion" Name="urn:simplesamlphp:v1:simplesamlphp" NameFormat="urn:oasis:names:tc:SAML:2.0:attrname-format:uri">
<saml:AttributeValue xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:xs="http://www.w3.org/2001/XMLSchema" xsi:type="xs:string">is</saml:AttributeValue>
<saml:AttributeValue xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:xs="http://www.w3.org/2001/XMLSchema" xsi:type="xs:string">really</saml:AttributeValue>
<saml:AttributeValue xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:xs="http://www.w3.org/2001/XMLSchema" xsi:type="xs:string">cool</saml:AttributeValue>
</saml:Attribute>
Each `<Attribute>` element requires a `NameFormat` attribute. This is
specified using curly braces at the beginning of the key name:
'EntityAttributes' => [
'{urn:simplesamlphp:v1}foo' => ['bar'],
],
This generates:
<saml:Attribute xmlns:saml="urn:oasis:names:tc:SAML:2.0:assertion" Name="foo" NameFormat="urn:simplesamlphp:v1">
<saml:AttributeValue xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:xs="http://www.w3.org/2001/XMLSchema" xsi:type="xs:string">bar</saml:AttributeValue>
</saml:Attribute>
When the curly braces are omitted, the NameFormat is automatically set
to "urn:oasis:names:tc:SAML:2.0:attrname-format:uri".
Examples
--------
If given the following configuration...
$metadata['https://www.example.com/saml/saml2/idp/metadata.php'] = [
'host' => 'www.example.com',
'certificate' => 'example.com.crt',
'privatekey' => 'example.com.pem',
'auth' => 'example-userpass',
'EntityAttributes' => [
'urn:simplesamlphp:v1:simplesamlphp' => ['is', 'really', 'cool'],
'{urn:simplesamlphp:v1}foo' => ['bar'],
],
];
... will generate the following XML metadata:
<?xml version="1.0"?>
<md:EntityDescriptor xmlns:md="urn:oasis:names:tc:SAML:2.0:metadata" xmlns:mdattr="urn:oasis:names:tc:SAML:metadata:attribute" xmlns:saml="urn:oasis:names:tc:SAML:2.0:assertion" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:mdui="urn:oasis:names:tc:SAML:metadata:ui" xmlns:ds="http://www.w3.org/2000/09/xmldsig#" entityID="https://www.example.com/saml/saml2/idp/metadata.php">
<md:Extensions>
<mdattr:EntityAttributes xmlns:mdattr="urn:oasis:names:tc:SAML:metadata:attribute">
<saml:Attribute xmlns:saml="urn:oasis:names:tc:SAML:2.0:assertion" Name="urn:simplesamlphp:v1:simplesamlphp" NameFormat="urn:oasis:names:tc:SAML:2.0:attrname-format:uri">
<saml:AttributeValue xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:xs="http://www.w3.org/2001/XMLSchema" xsi:type="xs:string">is</saml:AttributeValue>
<saml:AttributeValue xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:xs="http://www.w3.org/2001/XMLSchema" xsi:type="xs:string">really</saml:AttributeValue>
<saml:AttributeValue xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:xs="http://www.w3.org/2001/XMLSchema" xsi:type="xs:string">cool</saml:AttributeValue>
</saml:Attribute>
<saml:Attribute xmlns:saml="urn:oasis:names:tc:SAML:2.0:assertion" Name="foo" NameFormat="urn:simplesamlphp:v1">
<saml:AttributeValue xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:xs="http://www.w3.org/2001/XMLSchema" xsi:type="xs:string">bar</saml:AttributeValue>
</saml:Attribute>
</mdattr:EntityAttributes>
</md:Extensions>
<md:IDPSSODescriptor protocolSupportEnumeration="urn:oasis:names:tc:SAML:2.0:protocol">
<md:KeyDescriptor use="signing">
<ds:KeyInfo xmlns:ds="http://www.w3.org/2000/09/xmldsig#">
<ds:X509Data>
...
An example configuration to declare Géant Data Protection Code of Conduct
entity category support for a service provider in `authsources.php`:
'saml:SP' => [
...
'EntityAttributes' => [
'http://macedir.org/entity-category' => [
'http://www.geant.net/uri/dataprotection-code-of-conduct/v1'
]
],
'UIInfo' =>[
'DisplayName' => [
'en' => 'English name',
'es' => 'Nombre en Español',
],
'Description' => [
'en' => 'English description',
'es' => 'Descripción en Español',
],
'InformationURL' => [
'en' => 'http://example.com/info/en',
'es' => 'http://example.com/info/es',
],
'PrivacyStatementURL' => [
'en' => 'http://example.com/privacy/en',
'es' => 'http://example.com/privacy/es',
],
]
],