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File(s): conf/metadata-providers.xml
Format: Custom Schema

Overview

The Shibboleth IdP generally requires SAML metadata to provision connectivity with SAML relying parties and inform it about their capabilities and technical specifics. While you have the option to operate in a more "promiscuous" way (by enabling profiles for "unverified" RPs), this is not a common operating mode. In most cases, you will configure metadata sources in order to use the IdP's SAML features; this is done by adding <MetadataProvider> elements inside the metadata-providers.xml file.

Note that the other protocol(s) supported by the IdP generally support, but not strictly require, the use of SAML metadata, alongside other protocol-specific means of handling the same kinds of functions. Use of metadata enables a variety of useful configuration techniques that are superior to the features available from other approaches to managing relying parties and is generally advisable.

A typical use case is to load (and periodically reload) entity metadata from a local file:

 Load entity metadata from a file
<!--
    Load (and reload) entity metadata from a local file.

    The metadata refresh process is determined by the configured values of the 
    minRefreshDelay attribute (default: PT30S) and maxRefreshDelay attribute 
    (default: PT4H). If you want to load (or reload) the metadata immediately, 
    restart the IdP.
-->
<MetadataProvider id="LocalEntityMetadata" xsi:type="FilesystemMetadataProvider"
                  metadataFile="%{idp.home}/metadata/local-metadata.xml"/>

Another use case is to load (and periodically reload) a metadata aggregate from a remote source via HTTP:

 Load a metadata aggregate from a remote server
<!--
    Load (and reload) a signed metadata aggregate from a remote HTTP server.

    This sample configuration assumes: (1) the top-level element of the XML 
    document is signed; (2) the top-level element of the XML document is 
    decorated with a validUntil attribute; (3) the validity interval is two 
    weeks (P14D) in duration; and (4) the server supports HTTP conditional GET.

    The metadata refresh process is influenced by the configured values of 
    the minRefreshDelay attribute (default: PT30S) and the maxRefreshDelay 
    attribute (default: PT4H) and also by any cacheDuration and validUntil 
    attributes in the metadata itself. If the server does not support HTTP 
    conditional GET, the attributes should be adjusted accordingly.
-->
<MetadataProvider id="RemoteMetadataAggregate" xsi:type="FileBackedHTTPMetadataProvider"
                  backingFile="%{idp.home}/metadata/federation-metadata-copy.xml"
                  metadataURL="http://example.org/metadata/federation-metadata.xml">

    <!--
        Verify the signature on the root element of the metadata aggregate 
        using a trusted metadata signing certificate.
    -->
    <MetadataFilter xsi:type="SignatureValidation" requireSignedRoot="true"
		certificateFile="%{idp.home}/conf/metadata/md-cert.pem"/>

    <!--
        Require a validUntil XML attribute on the root element and
        make sure its value is no more than 14 days into the future.
    -->
    <MetadataFilter xsi:type="RequiredValidUntil" maxValidityInterval="P14D"/>

    <!-- Consume all SP metadata in the aggregate -->
    <MetadataFilter xsi:type="EntityRoleWhiteList">
        <RetainedRole>md:SPSSODescriptor</RetainedRole>
    </MetadataFilter>       

</MetadataProvider>

But increasingly, the dynamic providers (LocalDynamicMetadataProvider and DynamicHTTPMetadataProvider) are used in lieu of the reloading providers (FilesystemMetadataProvider and FileBackedHTTPMetadataProvider) shown above. See the MetadataManagementBestPractices topic for use cases and recommendations.

The ChainingMetadataProvider is often used to combine two or more metadata sources. The metadata-providers.xml file that ships with the software includes such a chain "wrapper" by default.

Namespaces and Schemas

Nearly all elements described in this page and its children are defined in the urn:mace:shibboleth:2.0:metadata namespace, the schema for which can be located at http://shibboleth.net/schema/idp/shibboleth-metadata.xsd. Throughout this document and its children, this is assumed to be the default XML namespace in effect. The namespace prefix "metadata:" is conventionally also bound to this namespace.

The namespace prefix "security:" is used to refer to the urn:mace:shibboleth:2.0:security namespace, the schema for which can be located at http://shibboleth.net/schema/idp/shibboleth-security.xsd, and is generally used only in advanced scenarios or for compatibility.

The namespace prefixes "samlmd:" and "md:" are used to refer to the urn:oasis:names:tc:SAML:2.0:metadata namespace, the schema for which can be located at http://docs.oasis-open.org/security/saml/v2.0/saml-schema-metadata-2.0.xsd

MetadataProvider Types

The precise behavior of any <MetadataProvider> element is controlled by the xsi:type attribute (see below). The following types are supported and examples are provided for each type. If the urn:mace:shibboleth:2.0:metadata namespace is not the default, then a prefix (presumably "metadata:") is required when specifying these types.

xsi:type

Function

ChainingMetadataProvider

A container for an ordered sequence of metadata providers of any type

DynamicHTTPMetadataProvider

A dynamic provider that fetches metadata just-in-time from a suitably configured HTTP server

LocalDynamicMetadataProvider

A dynamic provider that fetches metadata just-in-time from a local source such as a filesystem directory

FilesystemMetadataProvider

A reloading provider that loads (and reloads) a metadata file from the filesystem in a background thread

FileBackedHTTPMetadataProvider

A reloading provider that loads (and reloads) a metadata file from an HTTP server in a background thread

ResourceBackedMetadataProvider

A reloading provider that loads (and reloads) a metadata file from a more complex resource type (in a background thread)

InlineMetadataProvider

A provider that allows metadata to be specified inline

Reference

Configuration options common to two or more metadata providers are listed in the subsections below. Others are specific to the xsi:type, and these are documented on the pages specific to each type.

 Common XML Attributes

Name

Type

Default

Description

The following attributes are required on all metadata provider types:

id

String


Identifier for logging, identification for command line reload, etc.

xsi:type

String

Specifies the exact type of provider to use (from those listed above, or a custom extension type)

The following attributes are common to all metadata provider types except the ChainingMetadataProvider type:

requireValidMetadata

Boolean

true

Whether candidate metadata found by the resolver must be valid in order to be returned (where validity is implementation specific, but in SAML cases generally depends on a validUntil attribute.) If this flag is true, then invalid candidate metadata will not be returned.

failFastInitialization

Boolean

true

Whether to fail initialization of the underlying MetadataResolverService (and possibly the IdP as a whole) if the initialization of a metadata provider fails. When false, the IdP may start, and will continue to attempt to reload valid metadata if configured to do so, but operations that require valid metadata will fail until it does.

sortKey

Integer

Defines the order in which metadata providers are searched (see below), can only be specified on top level <MetadataProvider> elements.

The following are advanced settings supporting a new low-level feature allowing metadata lookup by keys other than the unique entityID and are rarely of use to a deployer.

criterionPredicateRegistryRef

Bean ID

Identifies the a custom CriterionPredicateRegistry bean used in resolving predicates from non-predicate input criteria

useDefaultPredicateRegistry

Boolean

true

Flag which determines whether the default CriterionPredicateRegistry will be used if a custom one is not supplied explicitly

satisfyAnyPredicates

Boolean

false

Flag which determines whether predicates used in filtering are connected by a logical 'OR' (true) or by logical 'AND' (false)


 Reloading XML Attributes
The following attributes are common to all reloading "batch-oriented" metadata providers (i.e., FileBackedHTTPMetadataProviderFilesystemMetadataProvider, and ResourceBackedMetadataProvider):

Name

Type

Default

Description

minRefreshDelay

Duration

PT30S

Lower bound on the next refresh from the time calculated based on the metadata's expiration

maxRefreshDelay

Duration

PT4H

Upper bound on the next refresh from the time calculated based on the metadata's expiration

refreshDelayFactor

Real Number (strictly between 0.0 and 1.0)

0.75

A factor applied to the initially determined refresh time in order to determine the next refresh time (typically to ensure refresh takes place prior to the metadata's expiration). Attempts to refresh metadata will generally begin around the product of this number and the maximum refresh delay.

expirationWarningThreshold

Duration

PT0S (disabled)

For each attempted metadata refresh (whether or not fresh metadata is obtained), if requireValidMetadata is true, and there is a validUntil XML attribute on the document root element, and the difference between validUntil and the current time is less than expirationWarningThreshold, the system logs a warning about the impending expiration.

indexesRef

Bean ID


Bean ID of a Set<MetadataIndex> used to support resolution of metadata based on criteria other than an entityID, e.g. resolving by protocol endpoint for CAS or by SAML Artifact source ID.

resolveViaPredicatesOnly

Boolean

false

Flag indicating whether resolution may be performed solely by applying predicates to the entire metadata collection, when an entityID input criterion is not supplied

parserPoolRef

Bean ID

shibboleth.ParserPool

Identifies a Spring bean for the XML parser used to parse metadata. Generally should not be changed.

taskTimerRef

Bean ID


Identifies a Spring bean containing a Java Timer used to schedule reloads. When not set, an internal one is created. Generally should not be changed.



 Dynamic XML Attributes
The following attributes are common to all dynamic metadata providers (i.e., DynamicHTTPMetadataProvider and LocalDynamicMetadataProvider):

Name

Type

Default

Description

parserPoolRef

Bean ID

shibboleth.ParserPool

Identifies a Spring bean for the XML parser used to parse metadata. Generally should not be changed.

taskTimerRef

Bean ID


Identifies a Spring bean containing a Java TaskTimer used to schedule reloads. When not set, an internal timer is created. Generally should not be changed.

refreshDelayFactor

Real Number (strictly between 0.0 and 1.0)

0.75

A factor applied to the initially determined refresh time in order to determine the next refresh time (typically to ensure refresh takes place prior to the metadata's expiration). Attempts to refresh metadata will generally begin around the product of this number and the maximum refresh delay.

minCacheDuration

Duration

PT10M

The minimum duration for which metadata will be cached before it is refreshed

maxCacheDuration

Duration

PT8H

The maximum duration for which metadata will be cached before it is refreshed

maxIdleEntityData

Duration

PT8H

The maximum duration for which metadata will be allowed to be idle (no requests for it) before it is removed from the cache

removeIdleEntityData

Boolean

true

Flag indicating whether idle metadata should be removed

cleanupTaskInterval

Duration

PT30M

The interval at which the internal cleanup task should run. This task performs background maintenance tasks, such as the removal of expired and idle metadata.

persistentCacheManagerRef

Bean ID


The optional manager for the persistent cache store for resolved metadata. On metadata provider initialization, data present in the persistent cache will be loaded to memory, effectively restoring the state of the provider as closely as possible to that which existed before the previous shutdown. Each individual cache entry will only be loaded if 1) the entry is still valid as determined by the internal provider logic, and 2) the entry passes the (optional) predicate supplied via initializationFromCachePredicateRef.

persistentCacheManagerDirectory

Directory path


The directory used for an internally-constructed filesystem-based persistent cache. This is a convenience parameter to avoid specifying a full bean via persistentCacheManagerRef. This option will be ignored if persistentCacheManagerRef is specified.

NOTE: Do NOT specify a directory containing other metadata or any other content under local control, as the cache manager may alter those files, or fail to process them correctly, or both. Use a dedicated directory for each provider.

persistentCacheKeyGeneratorRef

Bean ID

internal default instance

Identifies a Spring bean for a Function which generates the string key used with the cache manager. The default implementation produces the lower-case hex-encoded SHA-1 digest of the entityID of the EntityDescriptor.

initializeFromPersistentCacheInBackground

Boolean

true

Flag indicating whether should initialize from the persistent cache in the background. Initializing from the cache in the background will improve IdP startup times.

backgroundInitializationFromCacheDelay

Duration

PT2S

The delay after which to schedule the background initialization from the persistent cache when initializeFromPersistentCacheInBackground=true.

initializationFromCachePredicateRef

Bean ID

"always true" predicate

Identifies a Spring bean for an optional Predicate which determines whether a given entity should be loaded from the persistent cache at resolver initialization time.


 HTTP XML Attributes
The following attributes are common to all HTTP metadata providers (i.e., DynamicHTTPMetadataProvider FileBackedHTTPMetadataProvider

An HTTP metadata provider includes a default implementation of the org.apache.http.client.HttpClient interface. The attributes in the following subsections control the behavior of the default HTTP client. In most cases, the default behavior is sufficient.

To override the default client implementation, configure the following attribute:

Name

Type

Description

httpClientRef

Bean ID

A reference to an externally defined Spring bean that specifies an org.apache.http.client.HttpClient object. This attribute conflicts with and overrides all of the other HTTP attributes. See the HttpClientConfiguration topic for more information.

Use of the httpClientRef attribute precludes the use of any and all of the HTTP attributes in the following subsections.

 HTTP Connection Attributes

The following attributes apply to the HTTP connections obtained and managed by an HTTP metadata provider:

Name

Type

Default

Description

connectionRequestTimeout

Duration

Depends on provider type

The maximum amount of time to wait for a connection to be returned from the HTTP client's connection pool manager. Set to PT0S to disable.

connectionTimeout

Duration

Depends on provider type

The maximum amount of time to wait to establish a connection with the remote server. Set to PT0S to disable.

socketTimeout

Duration

Depends on provider type

The maximum amount of time to wait between two consecutive packets while reading from the socket connected to the remote server. Set to PT0S to disable.

 HTTP Security Attributes

The following security-related attributes apply to any HTTP metadata provider:

Name

Type

Default

Description

disregardTLSCertificate

Boolean

false

If true, no TLS certificate checking will take place over an HTTPS connection.

Be careful with this setting, it is typically only used during testing. See the HttpClientConfiguration topic for more information.

httpClientSecurityParametersRef

Bean ID

A reference to an externally defined Spring bean that specifies an HttpClientSecurityParameters instance, which consolidates all HTTP security parameters including advanced TLS usage.

This attribute conflicts with and overrides any explicit TrustEngine implementation configured as an inline <TLSTrustEngine> element. See the HttpClientConfiguration topic for more information.

 HTTP Proxy Attributes

The following attributes configure an HTTP proxy for use with an HTTP metadata provider:

Name

Type

Description

proxyHost

String

The hostname of the HTTP proxy through which connections will be made

proxyPort

String

The port of the HTTP proxy through which connections will be made

proxyUser

String

The username used with the HTTP proxy through which connections will be made

proxyPassword

String

The password used with the HTTP proxy through which connections will be made



 Common XML Elements
The following child element is common to all MetadataProvider types except the ChainingMetadataProvider type:

<MetadataFilter>

0 or more

A metadata filter applied to candidate metadata as it flows through the metadata pipeline



Miscellany

 Multiple Configuration FIles

As described in the ReloadableServices documentation, the configuration is actually loaded from a bean whose name is specified by the property idp.service.metadata.resources, with the default value shibboleth.MetadataResolverResources (in turn defined in conf/services.xml to be a list with one entry: the file metadata-providers.xml)

You can, if you choose, override this with additional or different files or more advanced sources. Each resource usually is expected to supply a "top level" <MetadataProvider> element with attributes and child elements as described above. Search order amongst multiple top level elements is arbitrated by the sortKey attribute, where lower values are processed before higher ones.

It is also now possible to declare "by reference" metadata filters that are attached by reference, so it is possible to supply a resource whose top-level element is such a <MetadataFilter> in such cases.



 Search Ordering

If a specific relying party (as identified by a specific entityID) is duplicated in the metadata sources provided, then which precise entry is chosen is governed by the following rules:

  • Metadata sources combined via a chain are searched in the order in which they occur in the chain, and the first entry matching the entityID is returned.

  • If multiple "top level" Metadata Providers are provided then they are searched in an order derived from the (numeric) value of the sortKey attribute (lowest key first). If no sortKey is specified, then the search order is undefined.

  • In whatever order of sources is in effect, the first entry matching the entityID is returned.

  • If a single metadata source contains multiple entries with the same entityID, then which entry is returned is undefined (exception: invalid entries would be ignored in favor of valid ones in most cases).




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