Re: [quicwg/base-drafts] Don't allow use of AEAD_AES_128_CCM_8 (#2029)

Kazuho Oku <notifications@github.com> Thu, 22 November 2018 00:55 UTC

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Subject: Re: [quicwg/base-drafts] Don't allow use of AEAD_AES_128_CCM_8 (#2029)
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@mikkelfj I do not think we have an agreement on how we support AES128-CCM8.

One option is to require `len(pn) + len(payload)` to be 20 for the cipher-suite. The downside is that you would be required to pad a certain amount of bytes when the message is small.

The other option in to require `len(pn) + len(payload)` to be less than that, however we would be required to state that the connection cannot send more than 2<sup>32</sup> packets to avoid birthday attack on header protection (note: header protection key is not updated by Key Update).

I think it would be wise to leave the discussion to the people who are really interested in having AES128-CCM, rather than debating among us who are not really interested in supporting the ciphersuite.

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