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 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
This commit fixes the compile-time warnings that OpenSSL 3.0 raises for
our source-code. For the cases where this was necessary we now have two
implementations - one for OpenSSL 1.1 and earlier, and one for OpenSSL
3.0.
This also makes our testsuite pass with OpenSSL 3.0
Relates to GH-1379
This commit changes the SSL and X.509 logging formats to something that,
hopefully, slowly approaches what they will look like in the future.
X.509 log is not yet deduplicated; this will come in the future.
This commit introduces two new options, which determine if certificate
issuers and subjects are still logged in ssl.log. The default is to have
the host subject/issuer logged, but to remove client-certificate
information. Client-certificates are not a typically used feature
nowadays.
In the past I thought that this is not super interesting. However, it
turns out that this can actually contain a slew of interresting
information - like operating systems querying for the revocation of
software signing certificates, e.g.
So - let's just enable this as a default log for the future.
- Use `-b` most everywhere, it will save time.
- Start some intel tests upon the input file being fully read instead of
at an arbitrary time.
- Improve termination condition for some sumstats/cluster tests.
- Filter uninteresting output from some supervisor tests.
- Test for `notice_policy.log` is no longer needed.
This also required updating a test that required a root-certificate that
was removed from the Mozilla store - the test now directly includes that
specific root-cert.
Only used in one event, without any way to use the opaque for anything
else. At this point this just seems like a complication that has no
reason to be there.
This one adds a separate new case that has to be parsed differently - if
a hello-retry-request is sent, only the namedgroup is sent - without the
additional key material.
Support for the legacy extension is retained.
This also installs symlinks from "zeek" and "bro-config" to a wrapper
script that prints a deprecation warning.
The btests pass, but this is still WIP. broctl renaming is still
missing.
#239
DTLS now only outputs protocol violations once it saw something that
looked like a DTLS connection (at least a client hello). Before the
danger that it misinterprets something is too high.
It has a configurable number of invalid packets that it can skip over
(because other protocols might be interleaved with the connection) and a
maximum amount of Protocol violations that it outputs because of wrong
packet versions.
This field isn't publicly available via the OpenSSL 1.1 API, not used
in the base scripts, and has no example in the test suit, so removing
it is simpler than trying to support manually parsing it out of the
raw data.
When encountering an extension unknown to OpenSSL, we would read from
the wrong memory location. Also added a testcase to prevent this specific
case from happening again.
The way in which TLS 1.3 is negotiated was changed slightly in later
revisions of the standard. The final version is only sent in an
extension - while the version field in the server hello still shows TLS
1.2.
This patch makes ssl.log show the correct version again.
Now we only parse the SignatureAndHashalgorithm field in cases where it
is present. This change also takes care to respect SCTs, which do
include the SignatureAndHashalgorithm in their digitally-signed struct,
even when used in protocol versions that do not have the
SignatureAndHashalgorithm in the protocols digitally-signed struct.
I also added tests to make sure this does indeed work with TLS 1.1 - it
turns out that so far we did not have a single TLS 1.1 pcap.
This commit fixes a few small issues.
* server key exchange parameters are only parsed when a named curve is
given.
* I removed the ssl-verbose.bro and moved the functionality into the
testcase.
The information that we get with these events is likely irrelevant to
the majority of Bro users; I do not think that we have to ship a
script that uses them by default. A script like this would be
something to publish via the Bro package manager instead; this is the
approach that we have taken with a number of the recent SSL addition.
* I marked the ssl_server_curve event as deprecated. More information is
contained in the new ssl_ecdh_server_params event.
This is an events that is probably seldomly (or never) directly used
by anyone; I plan to completely remove it right after the 2.6 release.
It turns out that Chrome supports an experimental mode to support TLS
1.3, which uses a non-standard way to negotiate TLS 1.3 with a server.
This non-standard way to negotiate TLS 1.3 breaks the current draft RFC
and re-uses an extension on the server-side with a different binary
formatting, causing us to throw a binpac exception.
This patch ignores the extension when sent by the server, continuing to
correctly parse the server_hello reply (as far as possible).
From what I can tell this seems to be google working around the fact
that MITM equipment cannot deal with TLS 1.3 server hellos; this change
makes the fact that TLS 1.3 is used completely opaque unless one looks
into a few extensions.
We currently log this as TLS 1.2.
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.
This does not yet work for certificates, because this requires some
changing the ASN.1 structure before validation (we need to extract the
tbscert and remove the SCT extension before).
API will change in the future.
This commit add the table SSL::ct_logs to Bro. This table is populated
with information about the currently active certificate transparency
logs (data from Google). The data can, e.g., be used to identify which
Logs are being used in SCTs.
Re-enable logging, now in policy because it probably is interesting to
no-one. We also only log ocsp replies.
Fix all tests.
Fix an issue where ocsp replies were added to the x.509 certificate
list.
This event is the replacement for ssl_application_data, which is removed
in the same commit. It is more generic, containing more information than
ssl_application_dataand is raised for all SSL/TLS messages that are
exchanged before encryption starts.
It is used by Bro internally to determine when a TLS1.3 session has been
completely established. Apart from that, it can be used to, e.g.,
determine the record layer TLS version.
This exposes the record layer version of the fragment in addition to the
content type and the length. The ordering of the arguments in the event
is the same as the ordering in the protocol message (first type, then
version, then length).
This also includes a slight change to the analyzer, no longer calling
the generate function if the event is not used.
This change adds compression methods to the ssl_client_hello event. It
not being included was an oversight from a long time ago.
This change means that the signature of ssl_client_hello changes
slightly and scripts will have to be adjusted; since this is a commonly
used event, the impact of it might be higher than usually for event
changes.
Now the DTLS analyzer cleanly skips all STUN messages; no warnings
should be logged to dpd.log and parsing should work flawlessly with
intermixed STUN messages.
