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Overview of 0065 and 0071 CRs Group Name: SEC WG Source: Qualcomm Inc. , Overview of 0065 and 0071 CRs Group Name: SEC WG Source: Qualcomm Inc. , Phil Hawkes, Wolfgang Granzow Meeting Date: SEC#22. 1, 2016 -04 -13 Agenda Item: End-to-End Security and Group Authentication

Background • Qualcomm has two open CRs – SEC-2016 -0065 R 03 -CR_TS-0003_R 2_Updates_to_MAF_Text Background • Qualcomm has two open CRs – SEC-2016 -0065 R 03 -CR_TS-0003_R 2_Updates_to_MAF_Text – SEC-2016 -0071 R 01 -CR_TS-0003_Certificate_Enrolment • These changes solve a large set of problems – Not really possible to provide separate CRs for each problem, since there are interdependencies – All related to credential provisioning/distribution, mostly • E 2 E Security related, and • Better support for certificates (cert enrolment, cert authn w/ MAF) • This presentation gives an overview of those changes – Summary Slide followed by deeper dive into the individual problems and solutions. – Presentation does not fully describe solutions – see CRs 2

Summary Table Problem Differentiating between… Solution Summary MEF/remote provisioning Enrolment phase: per M 2 Summary Table Problem Differentiating between… Solution Summary MEF/remote provisioning Enrolment phase: per M 2 M SP MAF/key distribution Operational phase: establishing credentials on an as-needed basis SAEF, ESPrim and ESData should use same technologies for key provisioning (via MEF) and key distribution (via MAF) SAEF, ESPrim or ESData use single extended versions of key provisioning (via MEF) & key distribution (via MAF) Limiting scope of symmetric keys established by Security Usage Identifiers (SUIDs) defined MEF or MAF for security features – used to limit scope Certificate Enrolment [SEC-2015 -0549 R 02] Integrated into RSPFs Provisioning symmetric keys for MAF is “messy” Added MAF Activation MAF auth’n could use client + server certs Extend MAF handshake (DTLS/TLS) to allow Once Enrolee B is enrolled with MEF, allow reauthentication to retrieve symmetric key Allow use of a symmetric Enrolment Re. Authentication Key (Ker) generated during RSPF or provisioned certificate. Triggering remote mgmt RSPF can configure URI for remote mgmt 3

Differentiating MEF & MAF (1) • Difference: Enrolment phase vs Operational phase • MEF Differentiating MEF & MAF (1) • Difference: Enrolment phase vs Operational phase • MEF & Remote Security Provisioning Frameworks (RSPF) – Part of Enrolment of CSE or AE with an M 2 M SP or M 2 M Trust Enabler – Provisions long-lifetime credential: • Certificate or Symmetric key for authenticating with the M 2 M SP/MTE’s MAF • Certificate for securing communication directly with other entities (CSEs or AEs) • Scope-limited symmetric key for used directly in SAEF, ESPrim, ESData with another entity(ies) – Thereafter used infrequently, for establishing fresh credentials or establishing credentials with a new CSE/AE. • MAF & Key Distribution – Used during Operational Phase – Establishes short-lifetime credentials (symmetric keys) for a set of entities (entity =CSE/AE) to use in SAEF, ESPrim or ESData • MAF authenticates all entities • A good anology is the EAP framework – Used frequently, for establishing fresh credentials or establishing credentials with a new sets of entities. 4

Differentiating MEF & MAF (2) • Guidelines: When should I use a MEF to Differentiating MEF & MAF (2) • Guidelines: When should I use a MEF to provision a symmetric key for direct use in SAEF/ESPrim/ESdata? – If AE/CSE is expected to talk securely to the same entities all the time, then okay to use MEF to provision a long-term symmetric key – If AE/CSE might talk securely to changing sets of entities, then better for MEF to provision the AE/CSE with either • A credential for authenticating to a MAF, then using the MAF to distribute symmetric keys to the changing sets of entities. – In this context, it seems likely that the TEF described in clause 8. 6 is more like a MAF than a MEF. • A certificate that can be used to authenticate the AE/CSE to any entity that trusts the root CA of the certificate chain. • I haven’t got text discussing this in the CR – this is more appropriate in a “handbook” TR or similar 5

Key distribution/provisioning for E 2 E (1) • MAF, MAF-SAEF, MEF & RSPFs were Key distribution/provisioning for E 2 E (1) • MAF, MAF-SAEF, MEF & RSPFs were specified for key distribution/provisioning when we only had SAEFs for securing communication – Now we also have ESPrim and ESData • IDCC added clause 8. 6 “Remote Security Frameworks for End-to -End Security” defining TEF providing key distribution/provisioning for ESPrim & ESData – As mentioned earlier, more like MAF & operational-phase key distribution • There would be advantages to having same key distribution/provisioning technologies for all of SAEF, ESPrim, ESData – In particular, the overall system becomes less complex 6

Key distribution/provisioning for E 2 E (2) • [0071] MEF/RSPF Impact : – Add Key distribution/provisioning for E 2 E (2) • [0071] MEF/RSPF Impact : – Add text saying provisioned credentials may be used for ESPrim and ESData – Added support for Usage-Constrained Symmetric Keys, where usage may be MAF, SAEF, ESPrim, ESData … • [0065]MAF Impact : – Extracted MAF-specific details from clause 8. 2. 2. 3 on MAF-Based SAEF and put them in new clause 8. x – Added exchanges (within DTLS/TLS) • Between Source End-Point and MAF (MAF Key Registration) • Between Target End-Point and MAF (MAF Key Retrieval) – Added support for source-generated keys (as in clause 8. 6. 3) • Addition to existing support for “Bootstrapped” keys exported from TLS – Added support for limiting scope of keys to SAEF, ESPrim, ESData, … 7

Limiting Scope of Symmetric Keys • Best practice: limit scope within which symmetric key Limiting Scope of Symmetric Keys • Best practice: limit scope within which symmetric key is used – The safest mechanism is incorporating, into the key derivation, some identifier or label defining the scope • Impact – Security Usage Identifiers (SUIDs) limits scope to • A specific security feature (SAEF, ESPrim, ESData, others? ) • Specific option of security feature, where applicable – e. g. ESData can use a symmetric key for Encryption Only or Signature Only – [0071] MEF/RSPF Impact • Symmetric Keys derivation incorporates SUID – [0065] MAF Impact • Source End-Point provides MAF with SUID limiting scope of distributed credential • Target End-Point provides SUID to MAF when requesting credential • Currently, derivation of Bootstrapped Kc does not include SUID, but it could easily be changed to include SUID – Generation of source-generated Kc is out of scope. 8

Certificate Enrolment • Purpose – Provisioning Enrolee certificate on behalf of M 2 M Certificate Enrolment • Purpose – Provisioning Enrolee certificate on behalf of M 2 M SP or M 2 M Trust Enabler – MEF would be appropriate function to facilitate this. Could be part of RSPF – Suggested SEC-2015 -0549 R 02. Change implemented SEC-2016 -0071 • RSPF Impact [0071] – Previously, RSPF consisted of a TLS handshake providing mutual authentication of Enrolee and MEF – Added “Enrolment exchange” between Enrolee and MEF • Includes instruction from MEF to Enrolee triggering Certificate Enrolment via an identified URI • Updates Overview (8. 3. 1. 2), details in clause 8. 3. 2. 1 (referenced in 8. 3. 2. 2/3) – Added Certificate Enrolment Procedure call flow (Stage 2 only) • Stage 3: Propose using Enrolment over Secure Transport (EST) [RFC 7030], relying on mutual authentication in RSPF’s existing TLS handshake • Issue: EST is currently defined only for HTTP/TLS. Release 2 will only support certificate enrolment over HTTP/TLS. – This needs to be noted in CR – I haven’t implemented this change yet. 9

Enrolment Re-authentication • Purpose – Enrolee B may need to retrieve, from MEF, a Enrolment Re-authentication • Purpose – Enrolee B may need to retrieve, from MEF, a usage-limited symmetric key provisioned to Enrolee. – Makes sense to allow Enrolee B to use a credential established with MEF when Enrolee B enrolled • Enrolled Certificate or • Symmetric Enrolment Re-Authentication Key (Ker) • RSPF Impact [0071] – Generation of symmetric Enrolment Re-Authentication Key (Ker) and Enrolment Re-Authentication Key Identifier (Ker. Id) – Allowing Enrolee B to use enrolled certificate or Ker+Ker. Id for mutual authentication with MAF • Potentially could allow Enrolee to do this if previously enrolled – but this is not currently in the proposed text 10

Cert Authentication w/ MAF • Purpose – MAF Handshake (TLS/DTLS) currently only supports symmetric Cert Authentication w/ MAF • Purpose – MAF Handshake (TLS/DTLS) currently only supports symmetric keys – Certificate-based TLS might be preferable in some deployments • Advantage: no need for MAF to store secrets for every end-point • Impact – MAF Changes [0065] • MAF Credential Configuration and MAF Handshake are impacted. – RSPF Changes [0071] • If MEF instructs Enrolee to use a MAF, then MEF indicates to Enrolee whether to use symmetric key or certificate for authentication with MAF 11

MAF Activation • Purpose – Activates an End-Point’s service with a MAF and configures MAF Activation • Purpose – Activates an End-Point’s service with a MAF and configures end-point with info for using MAF • MAF Impact [0065] – If using RSPF, then • End-Point provides MAF with Ke. Id • MAF retrieves Master Credential Km – MAF configures the End-Point with • URIs for MAF Key Registration & Retrieval • Identity that MAF will associate with End-Point(o) • (if RSPF used) Master Credential Identifier Km. Id assigned by MAF – used thereafter instead of Ke. Id 12

Triggering Remote Management • Purpose – Enables the MEF to instruct/configure the Enrolee to Triggering Remote Management • Purpose – Enables the MEF to instruct/configure the Enrolee to perform remote management after the remote security provisioning is completed • RSPF Impact [0071] – As part of Enrolment Exchange, MEF may provide the base URI of a remote management server with which the Enrolee shall initiate contact for remote management 13