This is the equivalent to a connection history for SSL - and contains
information about which protocol messages were exchanged in which order.
Tests currently don't pass - I will update the ssl.log baselines after
doing another a bit invasive change that will change all the logs.
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.
This commit changes the logic that is used to tracks connection
establishment - and moves it from scriptland into the core.
TLS 1.3 connection establishment is much more finnicky for us than the
establishment of earlier versions - since we cannot rely on the CCS
message anymore (which is meaningless and not sent in a lot of cases).
With this commit, the ssl_encrypted_data message gets raised for
encrypted TLS 1.3 handshake messages - which is much more correct than
the behavior before that just interpreted them as plaintext messages.
I will refine this a bit more - at the moment the connection established
event happens a bit too early - earlier than TLS 1.3 connections
actually can be estasblished.
Part of GH-1323
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.
And switch Zeek's base scripts over to using it in place of
"connection_state_remove". The difference between the two is
that "connection_state_remove" is raised for all events while
"successful_connection_remove" excludes TCP connections that were never
established (just SYN packets). There can be performance benefits
to this change for some use-cases.
There's also a new event called ``connection_successful`` and a new
``connection`` record field named "successful" to help indicate this new
property of connections.
