OAuth 2.0 Security IETF OAuth WG Conference Call, 14th December 2012

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Agenda Discuss security requirements and use cases in order to get a better understanding of the design space outlined in

Use Case #1: Load Balancer

Notes for Use Case 1 To prevent a load balancer from being used channel bindings can be deployed. The operator of the resource server may decide to “terminate” application security also at the load balancer.

Use Case #2: “Unprotected” Resource

Notes for Use Case 2 This use case only assumes that TLS is not used by the resource server. OAuth 2.0 requires TLS to be used with the authorization server. Hence, a TLS-incapable OAuth 2.0 client requires more changes.

Use Case #3: Prevent Access Token Re-Use

Notes for Use Case 3 Assumption: –RS cannot re-generate Authenticator. Alternative solutions: 1.AS puts intended recipient (RS1) into the access token. 2.AS encrypts token with key known to RS1 only.

Use Case #4: AS-to-RS Relationship Anonymity Idea: AS should not know with whom a resource owner is talking to. Implications: –No RS info made available to the AS by the client –RS does not interact with the AS (in the backend). –AS signs access token

Open Issue: Client Instance Client authentication allow authentication to the AS. –Same credentials may be re-use by a number of different client instances Suggestion was made to offer authentication of a client instance. By whom would this identification be used and for what purpose? What identifier could be used?

Open Issue: Key Lifetime & Context The client obtains keying material from the AS. Questions: –Does it change when a new access token is requested? –Is it valid only for a specific RS? –When an access token with a new scope is requested does the keying material change? –Who contributes to the keying material: client, AS, or both? –Is there an explicit lifetime associated?