The generation of weird events, by default, are now rate-limited
according to these tunable options:
- Weird::sampling_whitelist
- Weird::sampling_threshold
- Weird::sampling_rate
- Weird::sampling_duration
The new get_reporter_stats() BIF also allows one to query the
total number of weirds generated (pre-sampling) which the new
policy/misc/weird-stats.bro script uses periodically to populate
a weird_stats.log.
There's also new reporter BIFs to allow generating weirds from the
script-layer such that they go through the same, internal
rate-limiting/sampling mechanisms:
- Reporter::conn_weird
- Reporter::flow_weird
- Reporter::net_weird
Some of the code was adapted from previous work by Johanna Amann.
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.
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.
Closes#1830.
* origin/topic/johanna/ocsp-sct-validate: (82 commits)
Tiny script changes for SSL.
Update CT Log list
SSL: Update OCSP/SCT scripts and documentation.
Revert "add parameter 'status_type' to event ssl_stapled_ocsp"
Revert "parse multiple OCSP stapling responses"
SCT: Fix script error when mime type of file unknown.
SCT: another memory leak in SCT parsing.
SCT validation: fix small memory leak (public keys were not freed)
Change end-of-connection handling for validation
OCSP/TLS/SCT: Fix a number of test failures.
SCT Validate: make caching a bit less aggressive.
SSL: Fix type of ssl validation result
TLS-SCT: compile on old versions of OpenSSL (1.0.1...)
SCT: Add caching support for validation
SCT: Add signed certificate timestamp validation script.
SCT: Allow verification of SCTs in Certs.
SCT: only compare correct OID/NID for Cert/OCSP.
SCT: add validation of proofs for extensions and OCSP.
SCT: pass timestamp as uint64 instead of time
Add CT log information to Bro
...
Move from using CCS (before: established) to just doing certificate
validation at the end of the connection.
This is (again) more robust in the case of aborted connection. I am
moving this into a hook because of the complexity of the
end-of-connection handling for SSL.
This should probably be extended to not just handle SSL validation, but
all other logging constructs that are currently called in _established.
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.
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 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.
* origin/topic/johanna/dtls:
a few more small script-level fixes
update test baselines
add a simple leak test for dtls
add signature for dtls client hello
Make the plugin structure more... legal.
Only force logging of SSL if it actually was the SSL analyzer that failed.
DTLS working.
Implement correct parsing of TLS record fragmentation.
Make handshake analyzer flow-based. This means we can feed data to it in chunks, which makes dealing with fragmentation a little bit more convenient.
When setting the SSL analyzer to fail, also stop processing data that already has been delivered to the analyzer, not just future data.
First step for a DTLS analyzer.
BIT-1347 #merged
Conflicts:
scripts/base/protocols/ssl/main.bro
testing/btest/Baseline/plugins.hooks/output
This allows the path for the default filter to be specified explicitly
when creating a stream and reduces the need to rely on the default path
function to magically supply the path.
The default path function is now only used if, when a filter is added to
a stream, it has neither a path nor a path function already.
Adapted the existing Log::create_stream calls to explicitly specify a
path value.
Addresses BIT-1324
This commit mostly does a lot of refactoring of the current SSL
analyzer, which is split into several parts.
The handshake protocol is completely taken out of the SSL analyzer and
was refactored into its own analyzer (called tls-handshake-analyzer).
This will also (finally) make it possible to deal with TLS record
fragmentation.
Apart from that, the parts of the SSL analyzer that are common to DTLS
were split into their own pac files. Both the SSL analyzer and the (very
basic, mostly nonfunctional) DTLS analyzer use their own pac files and
those shared pac files.
All SSL tests still pass after refactoring so I hope I did not break
anything too badly.
At the moment, we have two different modules in one directory and I
guess the way I am doing this might be an abuse of the system. It seems
to work though...
* origin/topic/johanna/ssl-resumption:
Update baseline of new SSL policy script for changes
update test baselines
Mark everything below 2048 bit as a weak key (Browsers will stop accepting 1024 bits soon, so we can be of that opinion too).
add information about server chosen protocol to ssl.log, if provided by alpn.
change SSL log to contain a boolean flag signaling if a session was resumed instead of the (usually not really that useful) session ID the client sent.
BIT-1279 #merged
This also fixes the heartbleed detector to work for encrypted attacks in this
branch again. It stopped working, because the SSL analyzer now successfully detects
established connections, and the scripts usually disable analyzing after that.
(The heartbeat branch should not have been affected)
At the moment, we have support for:
elliptic_curves: client supported elliptic curves
ec_point_formats: list of client supported EC point formats
application_layer_protocol_negotiation: list of supported application layer protocols (used for spdy/http2 negotiation)
server_name: server name sent by client. This was supported before, but... a bit brittle.
That means that, for example, connections that are terminated with an alert during the
handshake never appear in the ssl.log.
This patch changes this behavior - now all ssl connections that fire any event are logged.
The protocol confirmation of the ssl analyzer is moved to the client_hello instead to
the server hello. Furthermore, an additional field is added to ssl.log, which indicates
if a connection has been established or not (which probably indicates a handshake problem).
work fine now.
Todo:
* update all baselines
* fix the circular reference to the fa_file structure I introduced :)
Sadly this does not seem to be entirely straightforward.
addresses BIT-953, BIT-760
This is a larger internal change that moves the analyzer
infrastructure to a more flexible model where the available analyzers
don't need to be hardcoded at compile time anymore. While currently
they actually still are, this will in the future enable external
analyzer plugins. For now, it does already add the capability to
dynamically enable/disable analyzers from script-land, replacing the
old Analyzer::Available() methods.
There are three major parts going into this:
- A new plugin infrastructure in src/plugin. This is independent
of analyzers and will eventually support plugins for other parts
of Bro as well (think: readers and writers). The goal is that
plugins can be alternatively compiled in statically or loadead
dynamically at runtime from a shared library. While the latter
isn't there yet, there'll be almost no code change for a plugin
to make it dynamic later (hopefully :)
- New analyzer infrastructure in src/analyzer. I've moved a number
of analyzer-related classes here, including Analyzer and DPM;
the latter now renamed to Analyzer::Manager. More will move here
later. Currently, there's only one plugin here, which provides
*all* existing analyzers. We can modularize this further in the
future (or not).
- A new script interface in base/framework/analyzer. I think that
this will eventually replace the dpm framework, but for now
that's still there as well, though some parts have moved over.
I've also remove the dpd_config table; ports are now configured via
the analyzer framework. For exmaple, for SSH:
const ports = { 22/tcp } &redef;
event bro_init() &priority=5
{
...
Analyzer::register_for_ports(Analyzer::ANALYZER_SSH, ports);
}
As you can see, the old ANALYZER_SSH constants have more into an enum
in the Analyzer namespace.
This is all hardly tested right now, and not everything works yet.
There's also a lot more cleanup to do (moving more classes around;
removing no longer used functionality; documenting script and C++
interfaces; regression tests). But it seems to generally work with a
small trace at least.
The debug stream "dpm" shows more about the loaded/enabled analyzers.
A new option -N lists loaded plugins and what they provide (including
those compiled in statically; i.e., right now it outputs all the
analyzers).
This is all not cast-in-stone yet, for some things we need to see if
they make sense this way. Feedback welcome.
This allows replacing an ugly openssl-call from one of
the policy scripts. The openssl call is now replaced with
a still-but-less-ugly call to base64_encode.
I do not know if I split the Base64 classes in a "smart" way... :)
* origin/topic/matthias/notary:
Small cosmetic changes.
Give log buffer the correct name.
Simplify delayed logging of SSL records.
Implement delay-token style SSL logging.
More style tweaks: replace spaces with tabs.
Factor notary code into separte file.
Adhere to Bro coding style guidelines.
Enhance ssl.log with information from notary.
Closes#928
