Subject: [Acme] ACME notes from IETF99

From: "Salz, Rich" <[email-masked]>
Date: Thu, 24 Aug 2017 21:08:13 +0000

An anonymous correspondent sends the following.  I will try to upload them but it might be too late…

    1. draft-ietf-acme-acme
    
    The draft passed a second WGLC and has gone for IESG review. There are some minor editorial issues. No further work is expected.
    
    2. draft-ietf-acme-caa
    
    There was no presenter or slides. The CAA draft says what authentication mechanisms are available. It could also be used for non-acme mechanisms (eg browser CAs). That would mean maintaining a registry of tokens for authentication mechanisms and co-operation with the CA/B Forum. It is looking at improving its authentication stuff and would probably be receptive. CA/B Forum seems to lack focus though: might need them to commit to a deadline. The CA/B Forum has concerns that new baseline requirements will be backwards compatible.
    
    There was a unanimous hum for a solution that does acme and non-acme auth methods.
    
    3. draft-ietf-acme-star
    	
    The draft discusses auto-renewal mechanisms. It’s not clear what should be done when the certificate life and the Expire: header disagree. Perhaps an absolute date could be used for killing the certificate even if an acme client is renewing/refreshing lookups. Certificate revocation issues are not yet fully worked out. It was suggested acme certificates could use three values: is available from/is available until/drop dead date for automated renewal.
    
    A new version of the draft should be done for IETF100 and would probably go for WGLC.
    
    draft-ietf-acme-star-request
    
    This related draft was not discussed. It will probably get adopted as a WG document at a future meeting.
    
    4. draft-ietf-acme-telephone
    	
    Jon Peterson’s slides are here:
    
    https://www.ietf.org/proceedings/99/slides/slides-99-acme-stir-tns-for-acme-00.pdf
    
    Endpoints could have authentication tokens, though it’s more likely to be the intermediary (SIP proxy, SBC, etc) that holds these. Jon was/is trying to be neutral on how these tokens would be stored and accessed. Current thinking in the telco world is these would be in a database owned, operated and controlled by the telco responsible for the number (block). An ENUM like solution would be an obvious approach since both E.164 numbering and domain names use hierarchical name spaces. However telcos seem to be hostile to a DNS-based approach. 
    
    5. draft-ietf-acme-service-provider
    
    Mary Barnes’s slides are here: 
    https://datatracker.ietf.org/meeting/99/materials/slides-99-acme-acme-identifiers-and-challenges-for-voip-service-providers
    
    The draft’s been updated to account for the service provider code token used by SHAKEN (signature-based handling of asserted information using token), the specification adopted by two US telco bodies, ATIS and the SIP Forum. Richard Barnes suggested this could become a generic identification mechanism, not just for phone number sand SIP addresses.
    
    6. draft-ietf-acme-email-smime and draft-ietf-acme-email-tls
     
    Alexey Melnikov’s slides:
    https://datatracker.ietf.org/meeting/99/materials/slides-99-acme-acme-for-email-services
    
    Alexey said there’s a demand for authenticating IMAP(S) servers. The WG didn’t have a clear consensus for any of the three options he proposed. There was some objection to using a Service Name Indication in TLS. He agreed to drop that and continue with the options of using DNS SRV records (or similar) to specify the protocol and port number or adding extensions to SMTP and IMAP.
    
    The WG noted Alexey’s optimism for S/MIME. He claimed it is more widely deployed than most people realise. Some Outlook users are forced to use S/MIME.
    
    7. Recharter discussion
    
    This was over in a few seconds. AD Kathleen Moriarty said the WG should just update its milestones and charter and then inform the IESG. The WG did not seem to want or need a long debate over what the revised milestones and charter should be. The WG co-chairs will probably be responsible for updating these and getting WG consensus.
    
    8. AOB
    
    Someone asked if CAs would issue ACME-based certificates for acme. Richard Barnes said Digicert was still trying to work out what to do. They were interested in principle.
    
    Yoav Nir has replaced Ted Hardie as co-chair now that Ted has been appointed to the IAB.