Re: [TLS] Version in record MAC

Martin Thomson <martin.thomson@gmail.com> Mon, 19 October 2015 18:14 UTC

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Date: Mon, 19 Oct 2015 11:13:58 -0700
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From: Martin Thomson <martin.thomson@gmail.com>
To: Eric Rescorla <ekr@rtfm.com>
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Subject: Re: [TLS] Version in record MAC
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On 19 October 2015 at 11:12, Eric Rescorla <ekr@rtfm.com> wrote:
>
>
> On Mon, Oct 19, 2015 at 11:06 AM, Martin Thomson <martin.thomson@gmail.com>
> wrote:
>>
>> On 19 October 2015 at 09:28, Eric Rescorla <ekr@rtfm.com> wrote:
>> >      1. Don't MAC the version at all.
>> >      2. MAC the negotiated version (which should be clear at
>> >         this point).
>>
>>
>> 3. Nothing
>>
>> The version is implicit in the key derivation (yeah, there are lots of
>> rounds of HMAC between, but it's there.
>>
>> The sequence number is fed into the nonce.
>
>
> How is this different from #1?

#1 implies the sequence number is covered by the MAC.