Subject: [Trans] Removal of the use of digitally-signed (issue #174)

From: Eran Messeri <[email-masked]>
Date: Mon, 15 May 2017 17:00:55 +0100

In issue #174 <https://trac.ietf.org/trac/trans/ticket/174> Richard
suggests removing the use of digitally-signed in favour of the signature
description in prose used in TLS 1.3.

A PR to that effect:
https://github.com/google/certificate-transparency-rfcs/pull/260

Are there any opinions on the matter? Personally I don't mind either;
generally, digitally-signed unambiguously specifies what data the signature
is over, but in 6962-bis it's always over a well-defined data structure
(defined somewhere else).

Eran

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From: "Salz, Rich" <[email-masked]>
Date: Mon, 15 May 2017 16:51:03 +0000

> Are there any opinions on the matter? Personally I don't mind either; generally, digitally-signed unambiguously specifies what data the signature is over, but in 6962-bis it's always over a well-defined data structure (defined somewhere else).

No objection.

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From: Eran Messeri <[email-masked]>
Date: Mon, 22 May 2017 11:23:31 +0100

FYI I think we can get away by simply mentioning the SignatureScheme
enumeration from TLS 1.3 without forcing its use:
As Rob Stradling pointed out in the PR, one of the log's parameters is the
signature algorithm, so there's no point in repeating in every structure
the log signs.

What I propose in PR #260 is then to remove the algorithm parameter,
leaving only the signature, in the SignedTreeHeadDataV2 and
SignedCertificateTimestampDataV2. In the Signature Algorithms section, the
enum value for each signature algorithm is referred, to uniquely identify
it.