F-Ticks - A Federation Log Format
draft-johansson-fticks-01

Abstract

This document describes a log format for distributed identity federations that can be used as a tool for metering and statistics gathering.

Requirements Language

The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this document are to be interpreted as described in RFC 2119 [RFC2119].

Status of This Memo

This Internet-Draft is submitted in full conformance with the provisions of BCP 78 and BCP 79.

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This Internet-Draft will expire on April 6, 2014.

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Table of Contents

• 1. Introduction and Motivation
• 2. F-ticks Semantics
• 3. F-ticks Format
• 4. Common F-ticks Attributes
• 4.1. REALM
• 4.2. VISCOUNTRY
• 4.3. VISINST
• 4.4. CSI
• 4.5. RESULT
• 4.6. RP
• 4.7. AP
• 4.8. TS
• 4.9. AM
• 4.10. AL
• 4.11. PN
• 5. Examples
• 6. Acknowledgements
• 7. Security Considerations
• 8. Normative References
• Authors' Addresses

1. Introduction and Motivation

Identity federations are often built as loosly coupled systems of identity providers and relying parties. In such a system it is often important to collect statistics and meetering in a consistent way.

This document describes a simple (yet extensible) text logformat which can be to communicate the essential aspects of authentication events to log reception software (eg syslog [RFC5424]).

The f-ticks format has been deployed in eduroam for some years and has there proven to be very useful in metering that federation. This document describes efforts to extend the eduroam f-ticks format to other types of federations - including those based on the Security Association Markup Language (SAML) and GSS-EAP.

2. F-ticks Semantics

An F-ticks log stream consists of a series of F-ticks log messages, each one represents a single security association event. Each log message is generated at a federation entity (eg an identity provider or a relying party).

3. F-ticks Format

An F-ticks log message is a text string that fulfills the following ABNF [RFC5234]:

fticks = "F-TICKS/" federation-identifier "/" version attribute-list
label = 1*( ALPHA / DIGIT / '_' / '-' / ':' / '.' / ',' / ';')
federation-identifier = label
version = label
attribute-list = 1*("#" attribute "=" value ) "#"
value = label
attribute = 1*( ALPHA / DIGIT )

The federation-identifier and version can be used by federations and other communities to indicate the type of attributes used. This document does not describe any mandatory attributes but instead provides a list of attributes in use in various communities today.

Future versions of this document may want to define an IANA registry for f-tick attribute definitions.

Because of size constraints common to several log systems it is expected that f-ticks attributes are kept short.

4. Common F-ticks Attributes

In general a log consumer should not assume that any one attribute is present. Depending on the situation any one of these (or any other defined attributes) may be missing from an F-ticks message.

4.1. REALM

The REALM attribute is used to convey the AAA-realm (eg RADIUS) of the authentication event. The presence of the REALM attribute implies that the message was generated by a AAA-based identity provider.

4.2. VISCOUNTRY

The ISO country code of the entity that generated the log messages.

4.3. VISINST

TODO

4.4. CSI

The Calling Station ID of the subject associated with the authentication event. The presence of this attribute implies that the message was generated by an AAA-based identity provider.

4.5. RESULT

The success-state of the event - either 'OK' or 'FAIL'. For identity providers, this implies that a successful authentication request was returned to a relying party. For relying parties it means a successful authentication response was received from an identity provider.

4.6. RP

Relying Party identifier. A string uniquely identifying the relying party involved in the authentication event. This is typically a URI and will often be technology-dependent. Implementations should expect and be able to process any string.

4.7. AP

Asserting party identifier - often an identity provider. A string uniquely identifying the party making the claim towards the relying party. For an authentication event this is the identity provider. This is typically a URI and will often be technology-dependent. Implementations should expect and be able to process any string.

4.8. TS

A POSIX timestamp (aka unix time) associated with the authentication event. If this attribute is absent the consumer MAY choose to use a timestamp provided by the log message system (eg syslog) instead.

4.9. AM

Authentication Method identifier. This is normally a URI that identifies the type of authentication that was used. Values may be technology-dependent.

4.10. AL

Assurance Level Identifier. This is normally a URN that identifies the level of assurance (aka LoA) that was associated with the security association event. Level of assurance identifiers SHOULD be registered according to RFC6711 [RFC6711] and SHOULD NOT be technology-dependent. If registered identifiers are used, their short form may be used depending on the underlying technology used. Long-form (URI) and short-form level-of assurance identifiers are equivalent.

4.11. PN

A unique identifier for the subject involved in the event.

5. Examples

TBD

6. Acknowledgements

The f-ticks log format was originally conceived as a usage-tracking mechanism by Stefan Winter.

7. Security Considerations

Improperly configured logging may leak sensitive user information. In particular the PN attribute value (subject identitier) should be masked with a cryptographically keyed hash function before transmission. A simple and secure way to do this is to use SHA256-HMAC followed by at least 100 rounds of PBKDF2. For passwords it is usually recommended to run several orders of magnitude more rounds but PN is essentially a username and does not carry the same security properties as a credential.

8. Normative References

Authors' Addresses