zeek/scripts/policy/protocols/ssl/log-hostcerts-only.bro
2014-03-19 21:32:01 -07:00

65 lines
1.7 KiB
Text

##! When this script is loaded, only the host certificates (client and server)
##! will be logged to x509.log. Logging of all other certificates will be suppressed.
module X509;
export {
redef record Info += {
# Logging is suppressed if field is set to F
logcert: bool &default=T;
};
}
# We need both the Info and the fa_file record modified.
# The only instant when we have both, the connection and the
# file available without having to loop is in the file_over_new_connection
# event.
# When that event is raised, the x509 record in f$info (which is the only
# record the logging framework gets) is not yet available. So - we
# have to do this two times, sorry.
# Alternatively, we could place it info Files::Info first - but we would
# still have to copy it.
redef record fa_file += {
logcert: bool &default=T;
};
function host_certs_only(rec: X509::Info): bool
{
return rec$logcert;
}
event bro_init() &priority=2
{
local f = Log::get_filter(X509::LOG, "default");
Log::remove_filter(X509::LOG, "default"); # disable default logging
f$pred=host_certs_only; # and add our predicate
Log::add_filter(X509::LOG, f);
}
event file_over_new_connection(f: fa_file, c: connection, is_orig: bool) &priority=2
{
if ( ! c?$ssl )
return;
local chain: vector of string;
if ( is_orig )
chain = c$ssl$client_cert_chain_fuids;
else
chain = c$ssl$cert_chain_fuids;
if ( |chain| == 0 )
{
Reporter::warning(fmt("Certificate not in chain? (fuid %s)", f$id));
return;
}
# Check if this is the host certificate
if ( f$id != chain[0] )
f$logcert=F;
}
event x509_certificate(f: fa_file, cert_ref: opaque of x509, cert: X509::Certificate) &priority=2
{
f$info$x509$logcert = f$logcert; # info record available, copy information.
}