Naming the analyzer different than the old one was a mistake that
required unnecessary code changes; keeping the old name makes things
like StartTLS in other protocol work without additional code changes.
This commit changes DPD matching for TLS connections. A one-sided match
is enough to enable DPD now.
This commit also removes DPD for SSLv2 connections. SSLv2 connections do
basically no longer happen in the wild. SSLv2 is also really finnicky to
identify correctly - there is very little data required to match it, and
basically all matches today will be false positives. If DPD for SSLv2 is
still desired, the optional signature in policy/protocols/ssl/dpd-v2.sig
can be loaded.
Fixes GH-1952
The dpd signature missed a few cases that are used for TLS 1.3,
especially when draft versions (which are all that we are seeing at the
moment) are being negotiated.
This fix mostly allows draft versions in the server hello (identified by
7F[version]; since we do not know how many drafts there will be, we are
currently allowing a rather safe upper limit.
The alert in this case is caused by the server name in the SNI not being
recognized by the server, which triggers an alert. Since the server is
an apache, and this might happen reasonably often, the new signature
allows one TLS alert before the server hello is expected.
- This caused us to lose signatures for POP3 and Bittorrent. These will
need discovered in the repository again when we add scripts
for those analyzers.
