Original Message From: Blumenthal, Uri - 0553 - MITLL via RT Sent: Friday, August 7, 2015 11:52 AM To: dw...@infradead.org Reply To: r...@openssl.org Cc: openssl-dev@openssl.org Subject: Re: [openssl-dev] [openssl.org #3992] [PATCH] Allow RFC6962 Signed Certificate Timestamps to be disabled
Considering emerging attacks against UEFI I'd be hesitant weakening protection mechanisms, even those that *currently* aren't likely to be used. Sent from my BlackBerry 10 smartphone on the Verizon Wireless 4G LTE network. Original Message From: David Woodhouse via RT Sent: Friday, August 7, 2015 10:56 Reply To: r...@openssl.org Cc: openssl-dev@openssl.org Subject: Re: [openssl-dev] [openssl.org #3992] [PATCH] Allow RFC6962 Signed Certificate Timestamps to be disabled On Fri, 2015-08-07 at 08:58 +0000, Ben Laurie via RT wrote: > I am curious why you think you don't need CT for UEFI? The use case for OpenSSL within UEFI is for Secure Boot — checking PKCs#7 signatures on bootloader / operating system images. Referring to RFC6962... Abstract This document describes an experimental protocol for publicly logging the existence of Transport Layer Security (TLS) certificates as they are issued or observed, in a manner that allows anyone to audit certificate authority (CA) activity and notice the issuance of suspect certificates as well as to audit the certificate logs themselves. The intent is that eventually clients would refuse to honor certificates that do not appear in a log, effectively forcing CAs to add all issued certificates to the logs. I don't really see a viable use case for this in the UEFI environment. We don't have a way to get these (hypothetical) logs of validly issued certificates into the firmware. We certainly don't normally have the facility to perform HTTPS requests prior to booting the OS. I realise that this scheme allows for asynchronous verification, but it would be utterly pointless to devise a complex scheme for interaction between the firmware and the booted OS, when the whole point is that the OS *isn't* trustworthy if that signature wasn't valid. Even aside from the general rule that *anything* we implement like that, some idiot will break when they do their "value subtract" to the standard open source UEFI offering. -- David Woodhouse Open Source Technology Centre david.woodho...@intel.com Intel Corporation _______________________________________________ openssl-dev mailing list To unsubscribe: https://mta.openssl.org/mailman/listinfo/openssl-dev