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This page aims to guide Federation Operators in supporting the adoption of the Sirtfi Framework

 

Coordinating Adoption

During the process of Sirtfi adoption, federation operators should anticipate providing support to entities.

 Two sets of Frequently Asked Questions are provided as a first resort

Please reach out to your REFEDS contacts should you, as a federation operator, require assistance. If you have no active members within REFEDS, contact us via contact@refeds.org and ask for the Sirtfi Working Group.   

Sirtfi Contact Choice

 Your federation may wish to provide specific guidance on the choice of Sirtfi Contact. For more information, visit the Guide to choosing a Sirtfi Contact.

Should your federation already provide centralised federated security incident response, you may choose to leverage this existing capability.  

Metadata Extensions

 How should your federation participants add the two required extensions to their metadata? The Guide for Federation Participants describes the two extensions in further detail.

 Be sure to communicate how an entity should assert their compliance and add their Sirtfi contact. Usually, federations choose to manage such metadata extensions centrally and act as the registrar. They would simply request the Sirtfi contact details from an entity via email.

Sample Outreach Letter for Federation Participants

Sample outreach letters have been provided below to assist with communication to your federation. Many thanks to Incommon and REN-ISAAC for their input.

Sample Outreach Letter

Dear Federation Members,

<THIS FEDERATION>, alongside international partners, strongly urge federation participants to be ready to manage federation-related security incidents. Here’s how.

Sirtfi [1] is an international framework for federated security incident response. It specifies a means to publish your readiness for incident response in federation metadata. This framework asks that each federation entity, ie, Identity and Service Providers, contain security contact information in its federation metadata; that normal security incident response procedures associated with it reasonably address the statements in the Sirtfi specification; and if so, that a Sirtfi tag is attached to the entity.

<THIS FEDERATION> recently made self-management of the security contact and Sirtfi flag available. Participant Site Administrators can now manage Sirtfi status for all systems that are part of the Federation. Please ask them to ensure that your security contact information is correctly expressed in federation metadata and to set the Sirtfi flag if you believe that your security incident response procedures reasonably meet the statements in the Sirtfi specification.

Academic collaborations, cloud services, and other uses depend on sensitive resources, such as unique instruments, software, high performance data processing environments, and corpi of data, being accessible through global federation. Most <THIS FEDERATION> participants are home to faculty, students, and staff that need to use these services to be successful in their endeavors. Please help them to succeed by being prepared to manage a federated security incident that could otherwise threaten valuable resources.

[1] https://refeds.org/sirtfi


Sample Outreach Letter 2

We invite you to join the Security Incident Response Trust Framework for Federated Identity, Sirtfi.

To improve security within <THIS FEDERATION>, and across eduGAIN, a trust framework has been defined that addresses concerns over operational security and incident response. By becoming Sirtfi compliant, your organisation will raise its level of assurance; Sirtfi creates an improved level of trust between federation participants resulting in increased collaboration between federated entities.

To find out more about Sirtfi, visit the homepage at https://refeds.org/sirtfi

To become Sirtfi compliant, refer to the Sirtfi Technical Wiki at https://wiki.refeds.org/display/SIRTFI/SIRTFI+Home

We recommend choosing <guidance on Sirfti contact choice> as your Sirtfi contact.

Two metadata extensions are required to become Sirtfi compliant, <we will manage these changes centrally||these should be added to your organisation’s metadata directly>

<ANY OTHER INFORMATION>

Regards,

Entity Attributes Filtering

The assertion of Sirtfi compliance for a Relying Party is expressed in metadata with the use of an Entity Attribute [1] as described in the OASIS documentation for asserting compliance with assurance profiles [2]. The validation strategy for local federation entity metadata might need to be reconsidered in order to allow local Entities to assert Sirtfi compliance. Additionally, if a federation has a filtering procedure in place while republishing eduGAIN metadata, federator operators need to ensure that their filtering strategy is adapted in order to facilitate the use of Sirtfi.

Two additions are necessary in the metadata of an entity asserting Sirtfi compliance so federation operators should focus on whitelisting/allowing the following :

Assurance-certification Entity Attribute

Sirtfi compliance is expressed with the use of  the Entity Attribute “urn:oasis:names:tc:SAML:attribute:assurance-certification” holding the value https://refeds.org/sirtfi in an entity’s metadata as seen below:

Sirtfi entity attribute
<md:EntityDescriptor xmlns:md="urn:oasis:names:tc:SAML:2.0:metadata" ...>
  <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"
            NameFormat="urn:oasis:names:tc:SAML:2.0:attrname-format:uri"
            Name="urn:oasis:names:tc:SAML:attribute:assurance-certification">
        <saml:AttributeValue>https://refeds.org/sirtfi</saml:AttributeValue>
      </saml:Attribute>
    </mdattr:EntityAttributes>
  </md:Extensions>
  ...
</md:EntityDescriptor>

Security Contact

A security contact element is added in every Entity that asserts Sirtfi compliance as seen below:

REFEDS security contact
<md:ContactPerson xmlns:md="urn:oasis:names:tc:SAML:2.0:metadata"
      contactType="other"
      remd:contactType="http://refeds.org/metadata/contactType/security"
      xmlns:remd="http://refeds.org/metadata">
  <md:GivenName>Security Response Team</md:GivenName>
  <md:EmailAddress>mailto:security@xxxxxxxxxxxxxxx</md:EmailAddress>
</md:ContactPerson>

Multiple EmailAddress tags may be defined, should an organisation wish to add both a generic email address and an individual.

This contactType has been defined within the REFEDS XSD Metadata Extension Schema.

[1] http://docs.oasis-open.org/security/saml/Post2.0/sstc-metadata-attr.html

[2] http://docs.oasis-open.org/security/saml/Post2.0/sstc-saml-assurance-profile.pdf 

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7 Comments

  1. The choice of namespace prefix icmd: works as well as any other but you probably want to change that since it stands for "InCommon metadata."

    1. Thanks, Tom. We've now changed this to "remd" for research and education metadata. 

  2. The pyFF example is very interesting but do you have a specific use case in mind? It’s not clear (to me) how these metadata files are intended to be used?

    Since interoperable IdPs do not filter SP metadata, I don't know why a federation operator would publish a subset of SP metadata. I'm not sure REFEDS should be suggesting this to federation operators?

    Earlier this week, we sent a message to IdP administrators in the InCommon Federation: “IdP deployments SHOULD NOT filter SP metadata. If you do, please self-assert the hide-from-discovery entity attribute.” Instead we encourage IdPs to “consume all the SP metadata in the world," which is a bit dramatic, I know, but it does get the point across.

    SP deployments are a different matter. SPs assume more risk than IdPs, so filtering metadata remains an option for SPs. OTOH, most SAML implementations can already do this. The Shibboleth SP software, for example, has extensive filter capabilities. As a federation operator, I’d be inclined to leave the filter configuration (if any) to the SP client. Creating a separate aggregate for every entity attribute of interest simply isn't gonna scale.

    1. Hi Tom,

      TBH when I got this task to create the page with instructions to federation operators, there was a task item titled : "Consider creating a Sirtfi filtered metadata list". Your arguments are valid, I am not aware of a valid use case3 for this. So, we could :

      •  leave the example with just the selectors so that it can be used as operators see fit ( i.e. print results for overview/statistics )
      • Replace the  whole "metadata aggregates for sirtfi compliant entities" with something simpler ( i.e. xmlstarlet commands to print the sirtfi compliant entities)
      • Remove this part entirely

      Hannah Short what's your take on this ?

       

    2. Hi guys, 

      Let's hold fire before deleting anything. Firstly, the need for a list of Sirtfi-compliant IdPs seems clear and undisputed, so the example here will be useful for Fed Ops. Services wishing to limit users to those deemed "secure" should be able to do so, plus this type of filtering is already in place for R&S. 

      Regarding a list of Sirtf-compliant SPs, I do appreciate how IdPs filtering SP metadata is potentially problematic; users will get half way through authenticating before it breaks. I see a clear need for this from IdPs that do not wish to expose their users to risk. We know there are incidents where it's not necessarily the identities but the servers themselves that are compromised due to poor operational security. 

      There should be very few IdPs who would wish to restrict their users to Sirtfi-compliant SPs (especially now since there is only 1...) but It may be a popular option once uptake is significant.

      Tom Scavo, "The Shibboleth SP software, for example, has extensive filter capabilities. As a federation operator, I’d be inclined to leave the filter configuration (if any) to the SP client" - and what about those SPs not using Shibboleth? I appreciate this is a minority but for those of us running ADFS, the situation is much more complicated.

      Ioannis Kakavas, "xmlstarlet commands to print the sirtfi compliant entities" would be a good addition! 

      I'll share this on the Sirtfi mailing list with you both in copy. 

      Cheers,

      1. "The Shibboleth SP software, for example, has extensive filter capabilities. As a federation operator, I’d be inclined to leave the filter configuration (if any) to the SP client" - and what about those SPs not using Shibboleth?

        The simpleSAMLphp SP will filter metadata.

        I appreciate this is a minority but for those of us running ADFS, the situation is much more complicated.

        AD FS can't even consume an aggregate so the point is moot. Roland's pysFEMMA utility will recognize entity attributes on the IdP side but AFAIK there is no similar tool on the SP side.

        Note that "recognizing entity attributes" on the IdP side is not the same as filtering SP metadata. An IdP's attribute release policy is based on entity attributes. IdPs do not limit their intake of metadata.

        A possible solution here is to reposition the pyFF example as something an SP owner might do. As the number of entity attributes in IdP metadata increases, only the SP owner knows which ones are right for her.

        I can only speak for myself, but as a federation operator, I want to get out of the business of publishing aggregates, at least new aggregates. Instead, we are running as fast as we can toward per-entity metadata. At that point, all that matters are the entity attributes.

        1. Hi Tom, 

          We discussed this on the call yesterday (I expected to see you but maybe it was too early?!) 

          The general consensus is that (as you've said) this should be determined by the SPs themselves, particularly since metadata aggregates will hopefully be a thing of the past soon. I have moved the text into a separate page. 

          Thanks for paying attention to this stuff

          Hannah