Re: [TLS] TLS 1.3 : small fragments attack
Peter Gutmann <pgut001@cs.auckland.ac.nz> Sat, 30 December 2017 05:39 UTC
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From: Peter Gutmann <pgut001@cs.auckland.ac.nz>
To: "tls@ietf.org" <tls@ietf.org>, Jitendra Lulla <lullajd@yahoo.com>
Thread-Topic: [TLS] TLS 1.3 : small fragments attack
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Date: Sat, 30 Dec 2017 05:38:52 +0000
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Subject: Re: [TLS] TLS 1.3 : small fragments attack
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Jitendra Lulla <lullajd@yahoo.com> writes: >But what if such records, from the same session, come in a quantity of 10000 >or more per second which could be generated by uploading a 500 MB file by the >client? My comment was meant as a general observation on how hard anomaly-detection is. At what point do you decide something is an attack? What if they send 2- byte messages? Or 1-byte messages with only 64 bytes of padding? Or 1 byte every $server_timeout_value-1 seconds? I think your idea in general is a good one, standards should include sanity limits on what you should and shouldn't accept (I've managed to cause crashes and reboots and whatnot on different servers by sending valid but unexpected data during development, SSH makes this particularly easy), but in cases like this it's hard to determine at which point you should and shouldn't accept the traffic. Peter.
- [TLS] TLS 1.3 : small fragments attack Jitendra Lulla
- Re: [TLS] TLS 1.3 : small fragments attack Peter Gutmann
- Re: [TLS] TLS 1.3 : small fragments attack Jitendra Lulla
- Re: [TLS] TLS 1.3 : small fragments attack Peter Gutmann
- Re: [TLS] TLS 1.3 : small fragments attack Viktor Dukhovni
- Re: [TLS] TLS 1.3 : small fragments attack Yoav Nir