[TLS] PR #1372: HKDF label

Eric Rescorla <ekr@rtfm.com> Sun, 09 February 2025 20:20 UTC

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From: Eric Rescorla <ekr@rtfm.com>
Date: Sun, 09 Feb 2025 12:19:30 -0800
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Subject: [TLS] PR #1372: HKDF label
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Hi folks,

David Benjamin noticed that there was some vagueness in the TLS and
DTLS specs about the exact prefix to use with HKDF-Expand-Label.

The following PR attempts to clarify what I think we agree on,
which is that extensions should use the label associated with
the version of TLS they are being used with:

  https://github.com/tlswg/tls13-spec/pull/1372

I think this is just a clarification, so if nobody objects by Friday
I'll plan to merge it.

-Ekr