Merge remote-tracking branch 'origin/master' into topic/seth/metrics-merge

scripts/policy/protocols/http/detect-MHR.bro

@@ -37,7 +37,7 @@ event log_http(rec: HTTP::Info)
 				local url = HTTP::build_url_http(rec);
 				local message = fmt("%s %s %s", rec$id$orig_h, rec$md5, url);
 				NOTICE([$note=Malware_Hash_Registry_Match,
-				        $msg=message, $id=rec$id, $URL=url]);
+				        $msg=message, $id=rec$id]);
 				}
 			}
 		}

scripts/policy/protocols/ssl/notary.bro

@@ -0,0 +1,105 @@
+@load base/protocols/ssl
+
+module CertNotary;
+
+export {
+	## A response from the ICSI certificate notary.
+	type Response: record {
+		first_seen: count &log &optional;
+		last_seen:  count &log &optional;
+		times_seen: count &log &optional;
+		valid:      bool  &log &optional;
+	};
+
+	## The notary domain to query.
+	const domain = "notary.icsi.berkeley.edu" &redef;
+}
+
+redef record SSL::Info += {
+	sha1:   string &log &optional;
+	notary: Response &log &optional;
+	};
+
+# The DNS cache of notary responses.
+global notary_cache: table[string] of Response &create_expire = 1 hr;
+
+# The records that wait for a notary response identified by the cert digest.
+# Each digest refers to a list of connection UIDs which are updated when a DNS
+# reply arrives asynchronously.
+global waitlist: table[string] of vector of SSL::Info;
+
+function clear_waitlist(digest: string)
+	{
+	if ( digest in waitlist )
+		{
+		for ( i in waitlist[digest] )
+			SSL::undelay_log(waitlist[digest][i], "notary");
+		delete waitlist[digest];
+		}
+	}
+
+event x509_certificate(c: connection, is_orig: bool, cert: X509,
+                       chain_idx: count, chain_len: count, der_cert: string)
+	{
+	if ( is_orig || chain_idx != 0 || ! c?$ssl )
+		return;
+
+	local digest = sha1_hash(der_cert);
+	c$ssl$sha1 = digest;
+
+	if ( digest in notary_cache )
+		{
+		c$ssl$notary = notary_cache[digest];
+		return;
+		}
+
+	SSL::delay_log(c$ssl, "notary");
+
+	local waits_already = digest in waitlist;
+	if ( ! waits_already )
+		waitlist[digest] = vector();
+	waitlist[digest][|waitlist[digest]|] = c$ssl;
+	if ( waits_already )
+		return;
+
+	when ( local str = lookup_hostname_txt(fmt("%s.%s", digest, domain)) )
+		{
+		notary_cache[digest] = [];
+
+		# Parse notary answer.
+		if ( str == "<???>" ) # NXDOMAIN
+			{
+			clear_waitlist(digest);
+			return;
+			}
+		local fields = split(str, / /);
+		if ( |fields| != 5 ) # version 1 has 5 fields.
+			{
+			clear_waitlist(digest);
+			return;
+			}
+		local version = split(fields[1], /=/)[2];
+		if ( version != "1" )
+			{
+			clear_waitlist(digest);
+			return;
+			}
+		local r = notary_cache[digest];
+		r$first_seen = to_count(split(fields[2], /=/)[2]);
+		r$last_seen = to_count(split(fields[3], /=/)[2]);
+		r$times_seen = to_count(split(fields[4], /=/)[2]);
+		r$valid = split(fields[5], /=/)[2] == "1";
+
+		# Assign notary answer to all records waiting for this digest.
+		if ( digest in waitlist )
+			{
+			for ( i in waitlist[digest] )
+				{
+				local info = waitlist[digest][i];
+				SSL::undelay_log(info, "notary");
+				info$notary = r;
+				}
+			delete waitlist[digest];
+			}
+		}
+	}