Re: [MLS] ClientInitKey Ambiguity

Michael Rosenberg <micro@fastmail.com> Tue, 20 August 2019 15:45 UTC

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From: Michael Rosenberg <micro@fastmail.com>
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Date: Tue, 20 Aug 2019 11:44:58 -0400
Cc: Messaging Layer Security WG <mls@ietf.org>
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To: Richard Barnes <rlb@ipv.sx>
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Subject: Re: [MLS] ClientInitKey Ambiguity
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> IIRC, the spec requires...that each ciphersuite appear once.  So “the public key for the group’s ciphersuite” should be well defined.  

I don't see this in the spec. I think this should be a requirement though: if a ciphersuite is defined in an MLS version that appears in ClientInitKey::supported_versions, it MUST appear in ClientInitKey::cipher_suites precisely once.