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SSL Analyzer: track connection direction by messages

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This PR changes the way in which the SSL analyzer tracks the direction
of connections. So far, the SSL analyzer assumed that the originator of
a connection would send the client hello (and other associated
client-side events), and that the responder would be the SSL servers.

In some circumstances this is not true, and the initiator of a
connection is the server, with the responder being the client. So far
this confused some of the internal statekeeping logic and could lead to
mis-parsing of extensions.

This reversal of roles can happen in DTLS, if a connection uses STUN -
and potentially in some StartTLS protocols.

This PR tracks the direction of a TLS connection using the hello
request, client hello and server hello handshake messages. Furthermore,
it changes the SSL events from providing is_orig to providing is_client,
where is_client is true for the client_side of a connection. Since the
argument positioning in the event has not changed, old scripts will
continue to work seamlessly - the new semantics are what everyone
writing SSL scripts will have expected in any case.

There is a new event that is raised when a connection is flipped. A
weird is raised if a flip happens repeatedly.

Addresses GH-2198.
This commit is contained in:
Johanna Amann 2022-06-24 19:27:13 +02:00 • committed by Johanna Amann
parent a7aa345c76
commit e14eddeb97
30 changed files with 344 additions and 179 deletions
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4
testing/btest/scripts/base/protocols/ssl/tls13-experiment.test
View file

@ -14,8 +14,8 @@
@load base/protocols/ssl
event ssl_extension(c: connection, is_orig: bool, code: count, val: string)
event ssl_extension(c: connection, is_client: bool, code: count, val: string)
{
if ( ! is_orig && code == 43 )
if ( ! is_client && code == 43 )
print bytestring_to_hexstr(val);
}