This commit introduces parsing of the CertificateRequest message in the
TLS handshake. It introduces a new event ssl_certificate_request, as
well as a new function parse_distinguished_name, which can be used to
parse part of the ssl_certificate_request event parameters.
This commit also introduces a new policy script, which appends
information about the CAs a TLS server requests in the
CertificateRequest message, if it sends it.
Introduce two new events for analyzer confirmation and analyzer violation
reporting. The current analyzer_confirmation and analyzer_violation
events assume connection objects and analyzer ids are available which
is not always the case. We're already passing aid=0 for packet analyzers
and there's not currently a way to report violations from file analyzers
using analyzer_violation, for example.
These new events use an extensible Info record approach so that additional
(optional) information can be added later without changing the signature.
It would allow for per analyzer extensions to the info records to pass
analyzer specific info to script land. It's not clear that this would be
a good idea, however.
The previous analyzer_confirmation and analyzer_violation events
continue to exist, but are deprecated and will be removed with Zeek 6.1.
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.
Documentation is missing and will be added in the next couple of hours.
* origin/topic/johanna/tls12-decryption: (24 commits)
TLS decryption: add test, fix small issues
Address PR feedback
TLS decryption: refactoring, more comments, less bare pointers
Small code fix and test baseline update.
SSL decryption: refactor TLS12_PRF
SSL decryption: small style changes, a bit of documentation
Deprecation and warning fixes
Clang-format updates
add missing call to EVP_KDF_CTX_set_params
TLS decryption: remove payload from ssl_encrypted_data again.
TLS 1.2 decryption: adapt OpenSSL 3.0 changes for 1.1
ssl: adapt TLS-PRF to openSSL 3.0
ssl/analyzer: potentially fix memory leaks caused by bytestrings
analyzer/ssl: several improvements
analyzer/ssl: defensive key length check + more debug logging
testing: feature gate ssl/decryption test
testing: add ssl/decryption test
analyzer/ssl: handle missing <openssl/kdf.h>
analyzer/ssl: silence warning in DTLS analyzer
analyzer/ssl: move proc-{client,server}-hello into the respective analyzers
...
This addresses feedback to GH-1814. The most significant change is the
fact that the ChipertextRecord now can remain &transient - which might
lead to improved speed.
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 refactors TLS decryption, adds more comments in scripts and
in C++ source-code, and removes use of bare pointers, instead relying
more on stl data types.
This policy script significantly extends the details that are logged
about SSL/TLS handshakes.
I am a bit tempted to just make this part of the default log - but it
does add a bunch logging overhead for each connection.
Extract-certs-pem writes pem files to a dedicated file; since it does
not really work in cluster-environments it was never super helpful.
This commit deprecates this file and, instead, adds
log-certs-base64.zeek, which adds the base64-encoded certificate (which
is basically equivalent with a PEM) to the log-file. Since, nowadays,
the log-files are deduplicates this should not add a huge overhead.
The ICSI notary is pretty much inactive. Furthermore - this approach
does no longer make much sense at this point of time - performing, e.g.,
signed certificate timestamp validation is much more worthwhile.
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.
- make TLS12 PRF a member function of the analyzer
- use std::string in PRF
- use StringValPtr instead of zeek::StringVal
- replace malloc/free with C++ style allocations
Several limitations still apply:
- TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384 is the only supported cipher suite
- Some tests are broken due to a failing assertion regarding bytestring
- No newly written tests for decryption (the patch was tested extensively for our paper)
- Several small open technical questions marked with FIXME
- Architecture in the ssl module might not be optimal
The larger number was substracted from the smaller one leading to an
integer overflow. However, no information was lost due to everything
also being present in the notice message.
Fixes GH-1454
Changes \x00-\x37 ranges to \x00-\x1f with assumption that the former
was attempting to match ASCII control characters, but mistook an octal
range for hex. This change reduces some false positives.
This adds a "policy" hook into the logging framework's streams and
filters to replace the existing log filter predicates. The hook
signature is as follows:
hook(rec: any, id: Log::ID, filter: Log::Filter);
The logging manager invokes hooks on each log record. Hooks can veto
log records via a break, and modify them if necessary. Log filters
inherit the stream-level hook, but can override or remove the hook as
needed.
The distribution's existing log streams now come with pre-defined
hooks that users can add handlers to. Their name is standardized as
"log_policy" by convention, with additional suffixes when a module
provides multiple streams. The following adds a handler to the Conn
module's default log policy hook:
hook Conn::log_policy(rec: Conn::Info, id: Log::ID, filter: Log::Filter)
{
if ( some_veto_reason(rec) )
break;
}
By default, this handler will get invoked for any log filter
associated with the Conn::LOG stream.
The existing predicates are deprecated for removal in 4.1 but continue
to work.
This adds two new functions: `Conn::register_removal_hook()` and
`Conn::unregister_removal_hook()` for registering a hook function to be
called back during `connection_state_remove`. The benefit of using hook
callback approach is better scalability: the overhead of unrelated
protocols having to dispatch no-op `connection_state_remove` handlers is
avoided.
Changes during merge
- Changed the policy script to use an event handler that behaves
for like the base script: &priority=5, msg$opcode != early-out,
no record field existence checks
- Also extended dns_query_reply event with original_query param
- Removed ExtractName overload, and just use default param
* 'dns-original-query-case' of https://github.com/rvictory/zeek:
Fixed some places where tabs became spaces
Stricter checking if we have a dns field on the connection being processed
Modified the DNS protocol analyzer to add a new parameter to the dns_request event which includes the DNS query in its original case. Added a policy script that will add the original_case to the dns.log file as well. Created new btests to test both.
- Updated the logic significantly: still filters out ICMP from being
considered an active service (like before) and adds a new
"Known::service_udp_requires_response" option (defaults to true) for
whether to require UDP server response before being considered an
active service.
* 'topic/dopheide/known-services' of https://github.com/dopheide-esnet/zeek:
Log services with unknown protocols
