1 / 23

ABFAB for Internet-of-Things

ABFAB for Internet-of-Things. Rhys Smith, Janet Sam Hartman & Margaret Wasserman, Painless Security. Agenda. ABFAB Overview ABFAB for IoT Q&A. Abfab overview. What is ABFAB?. Federated Identity for AuthN / AuthZ for any application/service

bary
Télécharger la présentation

ABFAB for Internet-of-Things

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. ABFAB for Internet-of-Things Rhys Smith, Janet Sam Hartman & Margaret Wasserman, Painless Security

  2. Agenda • ABFAB Overview • ABFAB for IoT • Q&A

  3. Abfab overview

  4. What is ABFAB? • Federated Identity for AuthN/AuthZ for any application/service • Designed to take the best of breed of existing technologies, giving: • Security • Flexibility / wide scope • Ease of integration • Scaling

  5. Fundamentals of ABFAB • ABFAB builds on AAA technologies • EAP (RFC 3748): strong & extensible mutual authentication • RADIUS (RFC 2865) / RadSec (RFC 6614): federation between domains • To this, ABFAB adds • SAML (OASIS standard), for rich authorisation semantics • Integration using operating system security APIs • SSPI: Windows • GSS-API (RFC 2078): Other operating systems • SASL (RFC 4422): Windows and other operating systems

  6. EAP • Extensible Authentication Protocol • Authentication Framework – Decouples actual authn method from your protocol. • Protocol negotiates particular authn method • Many exist (54 values currently registered) e.g. • EAP-PSK – Pre-shared key • EAP-TLS – X509 • EAP-SIM – SIM card authn (GSM uses this) • EAP-TTLS – X509 to create tunnel, then further authn within tunnel (e.g. PAP / MSCHAP)

  7. RADIUS / RadSec • RADIUS - AAA protocol over UDP • RadSec – RADIUS over TCP & TLS • Can encapsulate EAP

  8. AuthZ over AAA • EAP is an authn protocol • What about authz? • RADIUS /RadSec enables authz to be separate from authn • Directly, but may be limited (RADIUS attr’s) • ABFAB also defines SAML over AAA for finer-grained, flexible, authz information

  9. GSS-API / SSPI / SASL • How to integrate applications? • GSS-API / SSPI / SASL are ways to abstract security from applications • GS2 (RFC 5801) bridges SASL and GSS-API • ABFAB defines a GSS-API EAP mechanism (GSS-EAP)

  10. Actors in ABFAB • Client • Application/device attempting to access RP • Relying Party (RP) • Service that is ABFAB enabled • Identity Provider (IdP) • Authenticates users on behalf of that organisation • N.B. • Trust relationship between IdP and RP.

  11. ----- = Between Client App and RP===== = Between RP and IdP- - - = Between Client App and IdP (via RP) Protocol Overview Relying Client Identity Party App Provider | (1) | Client Configuration | | | |<-----(2)----->| | Mechanism Selection | | | |<-----(3)-----<| | NAI transmitted to RP | | | |<=====(4)====================>| Discovery | | | |>=====(5)====================>| Access request from RP to IdP | | | | |< - - (6) - -<| EAP method to Client | | | | |< - - (7) - ->| EAP Exchange to authenticate | | | Client | | | | | (8 & 9) Local Policy Check | | | |<====(10)====================<| IdP Assertion to RP | | | (11) | | RP processes results | | | |>----(12)----->| | Results to client app.

  12. Discovery • Most EAP methods have inner and outer tunnels • Stuff in outer tunnel is readable by bits in the middle • Stuff in inner tunnel only readable by the endpoints • Outer tunnel contains realm only ( e.g. @mit.edu) • This indicates IdP to use. • Inner tunnel contains credentials (e.g. someuser@mit.edu & password)

  13. Discovery • The RP and IdP need to know where each other are, and have keys for each other • Options: • Statically configured bi-lateral trust – RADIUS • Statically configured hierarchical trust = RADIUS (e.g. eduroam) • Dynamically created trust = Trust Router

  14. EAP EAP Flow with pre-configured keys Session GSS Service (Relying Party) Client Access-Accept RadSec RP Proxy Access-Accept RadSec IdP Proxy

  15. EAP EAP Flow with Trust Router Session GSS Service (Relying Party) Client Access-Accept RadSec RP Proxy T.I. TPQ Trust Router Trust Router Access-Accept RadSec Temporary Identity Trust Router IdP Proxy

  16. Requirements • Client • ABFAB libraries, Identity Selection Mechanism • Service • ABFAB libraries, RADSEC • RP • ABFAB libraries, RADSEC server • IdP • ABFAB libraries, RADSEC server, SAML server (opt)

  17. ABFAB libraries? • Moonshot • major implementation of ABFAB, from Janet. • Largely open source • Builds on Kerberos & Shibboleth SP code • GSS-API implementation (GSS-EAP)

  18. Abfab and Internet-of-things

  19. Overview • An ABFAB-style mechanism seems appropriate • Decoupled AuthN/AuthZ from core protocol • In a way that is flexible and extensible • Could use GSS-EAP directly – but that’s built for our application/service layer use cases • Or could use a custom ABFAB mechanism that better fits IoTrequirements • i.e. GSS-less ABFAB • E.g. EAP for authn, DTLS

  20. ABFAB++ • EAP’s decoupling of credential types and trust establishment from rest of system • ABFAB-style architecture – Separate out AuthN from AuthZ • Flexibility about client and AuthZ server. • Programmatic way of approaching AuthZ (AAA attributes)

  21. ABFAB-- • Multiple round trips in EAP – power req’s of this! • Need to optimise EAP • & use appropriate EAP method

  22. Making ABFAB better for ACE • An EAP method that works well with DICE/DTLS • Optimising EAP • Removing unnecessary EAP round trips • RADIUS over DTLS with DICE constraints (for authz server on constrained device) • Compression/better encoding of authz info • New instantiation of ABFAB arch – DTLS based

  23. Q&A?

More Related