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Re: HTTP/2.0 Magic

From: Eliot Lear <lear@cisco.com>
Date: Fri, 01 Feb 2013 12:04:49 +0900
Message-ID: <510B30D1.4070009@cisco.com>
To: Roberto Peon <grmocg@gmail.com>
CC: Martin Thomson <martin.thomson@gmail.com>, HTTP Working Group <ietf-http-wg@w3.org>
Separately we will also need a version identifier.  This field can ALSO
server as a version identifier.  We just rev/change the magic on a new

On 2/1/13 11:35 AM, Roberto Peon wrote:
> How about: d3 d0 c4 d9? (as an hommage).
> Honestly, though, anything which spells out something easy to remember
> in 7-bit ascii when the high-bits are all xor'd would be nice :)
> -=R
> On Thu, Jan 31, 2013 at 5:24 PM, Martin Thomson
> <martin.thomson@gmail.com <mailto:martin.thomson@gmail.com>> wrote:
>     The conclusion that we reached in the interim was that no matter how
>     HTTP/2.0 was started, there would be some magic that started the
>     session.
>     The requirements for that magic is that it is designed to cause a
>     reasonable proportion of HTTP/1.1 implementations to fail, preferably
>     to close the connection.
>     This magic also provides a high degree of confidence that the protocol
>     you are talking is actually HTTP/2.0 and not something else.
>     As far as I am aware, the actual sequence does not matter much, though
>     having the first bit set ensures that this isn't valid HTTP/1.1.
>     I generated a random number.  In this case, a 32-bit value.  Happily,
>     the high bit is set:
>       e1c54784
>     As we discussed, this would be sent at the start of every session and
>     be followed immediately by a SETTINGS frame.  Both client and server
>     send this sequence.
>     The concern here is that some implementations will swallow this and
>     proceed anyway.  Those implementations wont fail as a result of seeing
>     this.  It may be the case that for those implementations no amount of
>     magic is sufficient as the tests that lead to websockets masking
>     revealed.
Received on Friday, 1 February 2013 03:05:18 UTC

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