Re: [hybi] On TLS-only Approaches
"Brian Smith" <brian@briansmith.org> Mon, 23 August 2010 07:45 UTC
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From: Brian Smith <brian@briansmith.org>
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Date: Mon, 23 Aug 2010 02:45:56 -0500
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Subject: Re: [hybi] On TLS-only Approaches
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John Tamplin wrote: > It looks to me, according to openssl ciphers, the only NULL cipher > supported is AECDH-NULL-SHA which still does SHA1 for integrity > protection, so I assume it would have the same overhead. > RFC4346 seems to indicate a TLS_NULL_WITH_NULL_NULL > CipherSuite option which would have a 0-byte MAC, so presumably > you would only pay the 5-byte record overhead and there would be > no padding. That is more reasonable, but still seems large > considering we have been arguing over a few bytes in the framing. I don't think it's realistic to expect people to have unencrypted TLS cipher suites enabled. For one thing, people expect that "https" = "secure" = "encrypted" at a minimum. The AES-GCM modes are authenticated and encrypted and have 21 bytes of overhead per record. I think that's the minimum size overhead that you are going to get realistically. (I am 100% certain that there will be an AES-GCM implementation contributed to NSS soon.) Also, keep in mind that with TLS, you can use TLS compression, which allows you to compress the headers as well as the data, and which allows you to maintain compression state across requests and across responses. Consequently, it would be surprising to me if WebSockets over TLS didn't result in *smaller* messages when the TLS implementation supports compression. Memory overhead for compression is a concern but there are tricks to mitigate that. Regards, Brian
- Re: [hybi] On TLS-only Approaches Adam Barth
- Re: [hybi] On TLS-only Approaches John Tamplin
- [hybi] On TLS-only Approaches Eric Rescorla
- Re: [hybi] On TLS-only Approaches Roberto Peon
- Re: [hybi] On TLS-only Approaches John Tamplin
- Re: [hybi] On TLS-only Approaches Adam Barth
- Re: [hybi] On TLS-only Approaches John Tamplin
- Re: [hybi] On TLS-only Approaches Adam Barth
- Re: [hybi] On TLS-only Approaches Mark Nottingham
- Re: [hybi] On TLS-only Approaches Adam Barth
- Re: [hybi] On TLS-only Approaches Maciej Stachowiak
- Re: [hybi] On TLS-only Approaches Maciej Stachowiak
- Re: [hybi] On TLS-only Approaches Maciej Stachowiak
- Re: [hybi] On TLS-only Approaches John Tamplin
- Re: [hybi] On TLS-only Approaches Adam Barth
- Re: [hybi] On TLS-only Approaches Mike Belshe
- Re: [hybi] On TLS-only Approaches Mark Nottingham
- Re: [hybi] On TLS-only Approaches Brian Smith
- Re: [hybi] On TLS-only Approaches Shelby Moore
- Re: [hybi] On TLS-only Approaches Eric Rescorla
- Re: [hybi] On TLS-only Approaches Daniel Stenberg