SAML V2.0 Attribute Extensions Version 1.0

Committee Specification 01

4 August 2009

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OASIS Security Services TC


Hal Lockhart, BEA Systems, Inc.
Brian Campbell, Ping Identity Corporation


Scott Cantor, Internet2

Declared XML Namespaces(s):



This profile defines new XML attributes useful in extending the <saml:Attribute> element to communicate additional information about SAML attributes, their origin, rules for handling them, or any other kind of "meta-information" deemed interesting.


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Table of Contents

1 Introduction5

1.1 Notation5

1.2 Normative References5

2 SAML V2.0 Attribute Extensions7

2.1 Required Information7

2.2 Profile Overview7

2.3 OriginalIssuer7

2.3.1 Example7

2.4 LastModified7

2.4.1 Example8

3 Conformance9

3.0.1 SAML V2.0 Attribute Extensions9

Appendix A. Acknowledgements10

Appendix B. Revision History11


1 Introduction

Attribute extensions consist of XML attributes defined for inclusion in the various "attribute-extensible" elements in the SAML schema, as noted in section 7 of the SAML V2.0 core specification [SAML2Core].

This specification defines XML attributes for use within the <saml:Attribute> element to carry additional "meta-information" about a SAML attribute to a relying party. Such information is always considered optional and does not modify any of the normative processing rules defined by [SAML2Core].

1.1 Notation

This specification uses normative text.

The keywords "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this specification are to be interpreted as described in [RFC2119]:

…they MUST only be used where it is actually required for interoperation or to limit behavior which has potential for causing harm (e.g., limiting retransmissions)…

These keywords are thus capitalized when used to unambiguously specify requirements over protocol and application features and behavior that affect the interoperability and security of implementations. When these words are not capitalized, they are meant in their natural-language sense.

Listings of XML schemas appear like this.


Example code listings appear like this.

Conventional XML namespace prefixes are used throughout the listings in this specification to stand for their respective namespaces as follows, whether or not a namespace declaration is present in the example:


XML Namespace




This is the SAML V2.0 assertion namespace defined in the SAML V2.0 core specification [SAML2Core].



This is the namespace defined by this document and its accompanying schema [AttrExt-xsd].


This namespace is defined in the W3C XML Schema specification [Schema1]. In schema listings, this is the default namespace and no prefix is shown.


This is the XML Schema namespace for schema-related markup that appears in XML instances [Schema1].

This specification uses the following typographical conventions in text: <SAMLElement>, <ns:ForeignElement>, Attribute, Datatype, OtherCode.

1.2 Normative References

[AttrExt-xsd] OASIS Committee Draft 01, “SAML V2.0 Attribute Extension Schema”, December 2008.

[RFC2119]S. Bradner. Key words for use in RFCs to Indicate Requirement Levels. IETF RFC 2119, March 1997.

[SAML2Core]OASIS Standard, Assertions and Protocols for the OASIS Security Assertion Markup Language (SAML) V2.0. March 2005.

[Schema1]H. S. Thompson et al. XML Schema Part 1: Structures. World Wide Web Consortium Recommendation, May 2001. See Note that this specification normatively references [Schema2], listed below.

[Schema2]Paul V. Biron, Ashok Malhotra. XML Schema Part 2: Datatypes. World Wide Web Consortium Recommendation, May 2001. See

2 SAML V2.0 Attribute Extensions

2.1 Required Information

Identification: urn:oasis:names:tc:SAML:attribute:ext

Contact information:

Description: Given below.

Updates: None.

2.2 Profile Overview

This profile defines a set of optional XML attribute extensions that may appear in the <saml:Attribute> element to standardize the delivery of information found useful to SAML-enabled applications. As with all SAML extensions, these attributes are non-critical in nature, with no mandatory processing rules or intended impact on existing software or deployments.

Unless otherwise specified, these extension attributes should be understood to be composable, both with other extensions, and with any SAML profiles that make use of SAML attributes.

2.3 OriginalIssuer

The OriginalIssuer XML attribute identifies the entity that originally issued the containing SAML attribute and its values. It is analagous to the <saml:Issuer> element found in a SAML assertion, and allows the source of an attribute to be maintained for informational purposes across proxies/gateways, or in XML constructs other than SAML assertions.

The value of this attribute MUST be an entity identifier, per section 8.3.6 of [SAML2Core].

The following schema fragment defines the OriginalIssuer attribute:

<attribute name="OriginalIssuer" type="anyURI"/>

2.3.1 Example

The example below shows a SAML attribute with an OriginalIssuer extension.



Name="urn:oid:" FriendlyName="givenName"


<saml:AttributeValue xsi:type="xsd:string">Scott</saml:AttributeValue>


2.4 LastModified

The LastModified XML attribute indicates the date and time at which the containing SAML attribute's values were last modified, generally based on information kept at the attribute's ultimate source. See section 1.3.3 of [SAML2Core] for applicable rules on the use of date and time information in SAML constructs.

The following schema fragment defines the LastModified attribute:

<attribute name="LastModified" type="dateTime"/>

2.4.1 Example

The example below shows a SAML attribute with the LastModified extension.



Name="urn:oid:" FriendlyName="givenName"


<saml:AttributeValue xsi:type="xsd:string">Scott</saml:AttributeValue>


3 Conformance

3.0.1 SAML V2.0 Attribute Extensions

An asserting party can claim to support an extension attribute if it provides a means to include the XML attribute in the <saml:Attribute> information that it asserts.

A relying party can claim to support an extension attribute simply by demonstrating the ability to successfully process a <saml:Attribute> element that contains the XML attribute. Successful processing MAY consist of no changes to a relying party's behavior.

  1. Appendix A. Acknowledgements 

The editors would like to acknowledge the contributions of the OASIS Security Services Technical Committee, whose voting members at the time of publication were:

  1. Appendix B. Revision History