Snort mailing list archives
tls1.3 support for 'ssl_version' and DTLS
From: Joshua Kinard via Snort-devel <snort-devel () lists snort org>
Date: Mon, 30 Apr 2018 03:54:31 -0400
Curious, with the recent release of TLS 1.3, are there plans to update the "ssl_version" keyword to support a "tls1.3" parameter to detect it? I looked at trying this myself, but the kicker is that all of the SSL record flags use a single 32-bit bitfield that has all of its bits used up in src/dynamic-preprocessors/ssl_common/ssl.h. To add a new record flag for a "tls1.3" parameter would require either extending the bitfield to 64-bits and changing a lot of places to handle the larger data type, or break up the bitfield into multiple 32-bit variables. The latter option probably is the most sensible for the long-term, but neither is a trivial change. Also, going through some older rulesets, I noticed that the ssl_version keyword was used in a few cases for DTLS over UDP. The Snort manual nor README.ssl make mention of DTLS support. The rules in question are since disabled (e.g., SID 32382), but does the SSL Preprocessor handle DTLS? If it does, has any thought been given to support detecting the HelloVerifyRequest phase for DTLS 1.2 and lower, or the new HelloRetryRequest for DTLS 1.3, both within the "ssl_state" keyword? Both are used for passing a challenge cookie given that DTLS is used over connectionless protocols (for UDP and DCCP). -- Joshua Kinard Gentoo/MIPS kumba () gentoo org rsa6144/5C63F4E3F5C6C943 2015-04-27 177C 1972 1FB8 F254 BAD0 3E72 5C63 F4E3 F5C6 C943 "The past tempts us, the present confuses us, the future frightens us. And our lives slip away, moment by moment, lost in that vast, terrible in-between." --Emperor Turhan, Centauri Republic _______________________________________________ Snort-devel mailing list Snort-devel () lists snort org https://lists.snort.org/mailman/listinfo/snort-devel Please visit http://blog.snort.org for the latest news about Snort!
Current thread:
- tls1.3 support for 'ssl_version' and DTLS Joshua Kinard via Snort-devel (Apr 30)
- Re: tls1.3 support for 'ssl_version' and DTLS Russ via Snort-devel (Apr 30)
- Re: tls1.3 support for 'ssl_version' and DTLS Joshua Kinard via Snort-devel (Apr 30)
- Re: tls1.3 support for 'ssl_version' and DTLS Russ via Snort-devel (Apr 30)