CIS14: Working with OAuth and OpenID Connect

1. OAuth 2.0 and OpenID Connect Basics From OAuth2 to OpenID Connect by Roland Hedberg

2. Let’s start with OAuth2

3. ❖ The OAuth 2.0 authorization framework enables a third-party application to obtain limited access to an HTTP service, ! ❖ either on behalf of a resource owner by orchestrating an approval interaction between the resource owner and the HTTP service, ! ❖ or by allowing the third-party application to obtain access on its own behalf.

4. The players Authorization Server Resource ServerClient

5. Authorization Request Authorization Server Resource Server Client Authorization request

6. Authorization Request - details Parameters! client_id! redirect_uri! response_type! scope! state Authorization Server Resource Server Client Authorization request GET! http://example.com/authorization?state=1521671980316802035&! ! redirect_uri=https://example.org/authz_cb&! ! response_type=code&! ! client_id=SFEBuhC7sp3a

7. Authorization Server Resource Server Client AUTHENTICATION HAPPENS & End-user consent/authorization

8. Authorization Response Authorization Server Resource Server Client Authorization response

9. Authorization Response - details Authorization Server Resource Server Client Authorization response GET! https://example.org/authz_cb?state=1521671980316802035&! ! code=s87BT60pp2UbNX2HnkWpZ9YhPVHRZaoTuU9XJul6JMuQaKUidUM6y1Boab6 Parameters code! state access_token! token_type! expires_in! scope! state

10. Access Token Request Authorization Server Resource Server Client Access token request

11. Access Token Request - details POST! http://example.com/token! ! code=s87BT60pp2UbNX2HnkWpZ9YhPVHRZaoTuU9XJul6JMuQaKUidUM6y1Boab6&! ! grant_type=authorization_code&! ! redirect_uri=https://example.org/authz_cb Authorization Server Resource Server Client Access token request Parameters! client_id! code! grant_type! redirect_uri

12. Access Token Response Authorization Server Resource Server Client Access token response

13. Access Token Response - details {! ! 'access_token': ’s87BT60pp2UbNX2HnkWpfPfWNo9Gi7chACuWoa2IDND', ! ! 'expires_in': 3600, ! ! 'refresh_token': ’s87BT60pp2U+bNX2HnkWpVCnDYPsy8EOpI’! ! 'state': ’STATE0’,! ! 'token_type': 'Bearer', ! } Authorization Server Resource Server Client Access token response Parameters! access_token! expires_in! refresh_token scope! token_type

14. Resource Access Authorization Server Resource Server Client Resource request/response

15. Resource Access - details Authorization Server Resource Server Client Resource request/response GET! https://example.com/resource! ! Header:! ! Authorization: ’Bearer s87BT60pp2UbNX2HnkWpfPfWNo9Gi7chACuWoa2IDND’!

16. The whole Authorization Server Resource Server Client Authorization request Authorization Server Resource Server Client Authorization response Authorization Server Resource Server Client Access token request Authorization Server Resource Server Client Access token response Authorization Server Resource Server Client Resource request/response Authorization Server Resource Server Client AUTHENTICATION HAPPENS & End-user consent/authorization

17. Flows ❖ Authorization Code Grant! ❖ Implicit Grant! ❖ Resource Owner Password Credentials Grant! ❖ Client Credentials Grant

18. Implicit grant Authorization Server Resource Server Client Authorization request Authorization Server Resource Server Client Resource request/response Authorization Server Resource Server Client Authorization response Authorization Server Resource Server Client AUTHENTICATION HAPPENS & End-user consent/authorization

19. Resource Owner Password Credentials Grant & Client Credentials Grant Authorization Server Resource Server Client Access token request Authorization Server Resource Server Client Access token response Authorization Server Resource Server Client Resource request/response

20. From OAuth2 to OpenID Connect

21. ❖ OpenID Connect 1.0 is a simple identity layer on top of the OAuth 2.0 protocol. ! ❖ It enables Clients to verify the identity of the End-User based on the authentication performed by an Authorization Server, as well as to obtain basic proﬁle information about the End-User in an interoperable and REST-like manner.

22. The differences ❖ Only authorization grant and implicit grant ﬂows! ❖ Dynamic provider discovery and client registration! ❖ ID Token! ❖ Additions/Clariﬁcations/Constrictions! ❖ UserInfo endpoint

23. Flows ❖ Authorization code! ❖ Implicit! ❖ Hybrid (authorization code with a twist)! ❖ code id_token! ❖ code token! ❖ code id_token token

24. Dynamic provider discovery and client registration

25. Dynamic discovery and registration 1. Find the provider! 2. Discover provider info! 3. Register client

26. 1.Find the provider ❖ Webfinger (RFC 7033)! ❖ User identifier -> URL! ❖ carol@example.org ->! ! GET /.well-known/webfinger?! resource=acct:carol@example.com&! rel=http://openid.net/specs/connect/1.0/issuer! HTTP/1.1! Host: example.com

27. Webfinger response HTTP/1.1 200 OK! Access-Control-Allow-Origin: *! Content-Type: application/jrd+json! ! {! "subject" : "acct:carol@example.com",! "links" :! [ {! "rel" : "http://openid.net/specs/connect/1.0/issuer",! "href" : "https://openid.example.com"! } ]! }

28. 2.Discover provider info - query GET /.well-known/openid-conﬁguration HTTP/1.1! Host: openid.example.com

29. 2. Discover provider info - response ❖ issuer! ❖ jwks_uri! ❖ endpoints! ❖ functions supported! ❖ support for signing/encrypting algorithms! ❖ policy/tos

30. Required information ❖ issuer! ❖ jwks_uri! ❖ authorization_endpoint! ❖ token_endpoint (*)! ❖ response_types_supported! ❖ subject_types_supported! ❖ id_token_signing_alg_supported

31. 3. Client registration ❖ uris! ❖ application information! ❖ support for signing/encrypting algorithms! ❖ key material! ❖ server behavior! ❖ client behavior

32. required information ❖ redirect_uris

33. Client registration response ❖ client_id! ❖ possibly client_secret and if so client_secret_experies_at! ❖ and the Authorization servers view of things

34. An Authorization Server ❖ MAY add fields the client didn’t include.! ❖ MAY reject or replace any of the Client's requested field values and substitute them with suitable values.! ❖ MAY ignore values provided by the client, and MUST ignore any fields sent by the Client that it does not understand.

35. A Client can not ❖ modify a registration! ❖ delete a registration

36. ID Token

37. ID Token ❖ Have to make a detour into JWT/K/A/S/E land

38. JWT ❖ Jason Web Token! ❖ a compact URL-safe means of representing claims to be transferred between two parties! ❖ Suggested pronunciation: ’jot’

39. JWS represents content secured with digital signatures or Message Authentication Codes (MACs) using JavaScript Object Notation (JSON) based data structures. JWE represents encrypted content using JavaScript Object Notation (JSON) based data structures.

40. JWK a JavaScript Object Notation (JSON) data structure that represents a cryptographic key JWA registers cryptographic algorithms and identiﬁers to be used with the JSON Web Signature(JWS), JSON Web Encryption (JWE), and JSON Web Key (JWK) speciﬁcations

41. ID Token ❖a security token that contains Claims about the Authentication of an End-User by an Authorization Server when using a Client, and potentially other requested Claims. ! ❖is represented as a JSON Web Token (JWT)

42. ID Token claims -required ❖ iss - Issuer Identiﬁer for the Issuer of the response! ❖ sub - Subject Identiﬁer! ❖ aud - Intended audience! ❖ exp - Expiration time! ❖ iat - Issued at! ❖ auth_time - Authentication time! ❖ nonce

43. ID Token claims - optional ❖ acr - Authentication Context Class Reference! ❖ amr - Authentication Method References! ❖ azp - Authorized party

44. Additions/ Clarifications/ Constrictions

45. OAuth2 Authorization Request - details Parameters! client_id! redirect_uri! response_type! scope! state Authorization Server Resource Server Client Authorization request GET! http://example.com/authorization?state=1521671980316802035&! ! redirect_uri=https://example.org/authz_cb&! ! response_type=code&! ! client_id=SFEBuhC7sp3a

46. Authentication Request - OpenID Connect extensions ❖ response_mode - The mechanism to use for returning parameters! ❖ nonce - Associates client session with ID Token! ❖ Signed/encrypted Authentication Request! ❖ End-user interactions! ❖ Response details

47. Signed/encrypted Authentication Request ❖ request - by value! ❖ request_uri - by reference! ! ❖ Single self-contained parameter! ❖ Signed and/or encrypted (JWT)

48. End-user interactions ❖ display - How to display pages to End-User! ❖ prompt - If the End-User should be prompted for re-authentication/ consent! ❖ max_age - allowed max time since last authentication! ❖ ui_locales - End-User’s preferred languages and scripts! ❖ id_token_hint - ID Token previously issued ! ❖ login_hint - login identiﬁer the End-User might want to use! ❖ acr_values - requested Authentication Context Class Reference values

49. Response details ❖ claims! ❖ user_info! ❖ id_token! ! ❖ claims speciﬁcation! ❖ null! ❖ essential! ❖ value! ❖ values

50. UserInfo endpoint

51. User info ❖ sub! ❖ name! ❖ given_name! ❖ family_name! ❖ middle_name! ❖ nickname! ❖ preferred_username Set of standard claims ❖ profile! ❖ picture! ❖ website! ❖ email! ❖ email_verified! ❖ gender! ❖ birthdate ❖ zoneinfo! ❖ locale! ❖ phone_number! ❖ phone_number_verfied! ❖ address! ❖ updated_at!

52. claims types ❖ Normal! ❖ Aggregated! ❖ Distributed

53. Summary ❖ OAuth2 is about authorization! ❖ OpenID Connect adds authentication and identity information

54. Questions ?

CIS14: Working with OAuth and OpenID Connect

CloudIDSummit

CIS14: Working with OAuth and OpenID Connect