Report PostgreSQL login success only after ReadyForQuery

Previously, Zeek treated the receipt of `AuthenticationOk` as a
successful login. However, according to the PostgreSQL
Frontend/Backend Protocol, the startup phase is not complete until
the server sends `ReadyForQuery`. It is still possible for the server
to emit an `ErrorResponse` (e.g. ERRCODE_INVALID_AUTHORIZATION_SPECIFICATION)
after `AuthenticationOk` but before `ReadyForQuery`.

This change updates the PostgreSQL analyzer to defer reporting login
success until `ReadyForQuery` is observed. This prevents false
positives in cases where authentication succeeds but session startup
fails.

scripts/base/protocols/postgresql/main.zeek

@@ -53,7 +53,7 @@ export {
 		user: string &optional;
 		database: string &optional;
 		application_name: string &optional;
-		rows: count &default=0;
+		rows: count &optional;
 		errors: vector of string;
 	};
 
@@ -197,8 +197,6 @@ event PostgreSQL::authentication_ok(c: connection) {
 
 	c$postgresql$backend = "auth_ok";
 	c$postgresql$success = T;
-
-	emit_log(c);
 }
 
 event PostgreSQL::terminate(c: connection) {
@@ -224,6 +222,9 @@ event PostgreSQL::simple_query(c: connection, query: string) {
 event PostgreSQL::data_row(c: connection, column_values: count) {
 	hook set_session(c);
 
+	if ( ! c$postgresql_state?$rows )
+		c$postgresql_state$rows = 0;
+
 	++c$postgresql_state$rows;
 }
 
@@ -236,7 +237,11 @@ event PostgreSQL::ready_for_query(c: connection, transaction_status: string) {
 	if ( ! c$postgresql?$success )
 		c$postgresql$success = transaction_status == "I" || transaction_status == "T";
 
+	if ( c$postgresql_state?$rows ) {
 		c$postgresql$rows = c$postgresql_state$rows;
+		delete c$postgresql_state$rows;
+	}
+
 	emit_log(c);
 }
 

testing/btest/Baseline/scripts.base.protocols.postgresql.psql-login-no-role/conn.cut

@@ -0,0 +1,3 @@
+### BTest baseline data generated by btest-diff. Do not edit. Use "btest -U/-u" to update. Requires BTest >= 0.63.
+ts	uid	id.orig_h	id.orig_p	id.resp_h	id.resp_p	service
+XXXXXXXXXX.XXXXXX	CHhAvVGS1DHFjwGM9	10.21.179.53	51625	192.168.115.201	5432	postgresql

testing/btest/Baseline/scripts.base.protocols.postgresql.psql-login-no-role/postgresql.cut

@@ -0,0 +1,4 @@
+### BTest baseline data generated by btest-diff. Do not edit. Use "btest -U/-u" to update. Requires BTest >= 0.63.
+ts	uid	id.orig_h	id.orig_p	id.resp_h	id.resp_p	user	database	application_name	frontend	frontend_arg	backend	backend_arg	success	rows
+XXXXXXXXXX.XXXXXX	CHhAvVGS1DHFjwGM9	10.21.179.53	51625	192.168.115.201	5432	-	-	-	ssl_request	-	ssl_reply	N	F	-
+XXXXXXXXXX.XXXXXX	CHhAvVGS1DHFjwGM9	10.21.179.53	51625	192.168.115.201	5432	test	postgres	Navicat	startup	-	auth_ok,error	SeverityLocalized=FATAL,Severity=FATAL,Code=28000,Message=role "test" does not exist,File=miscinit.c,Line=694,Routine=InitializeSessionUserId	F	-

testing/btest/scripts/base/protocols/postgresql/psql-login-no-role.zeek

@@ -0,0 +1,12 @@
+# @TEST-DOC: Test Zeek parsing a trace file through the PostgreSQL analyzer.
+#
+# @TEST-REQUIRES: ${SCRIPTS}/have-spicy
+# @TEST-EXEC: zeek -b -r ${TRACES}/postgresql/psql-login-no-role.pcap %INPUT >output
+# @TEST-EXEC: zeek-cut -m ts uid id.orig_h id.orig_p id.resp_h id.resp_p service  < conn.log > conn.cut
+# @TEST-EXEC: zeek-cut -m < postgresql.log > postgresql.cut
+#
+# @TEST-EXEC: btest-diff conn.cut
+# @TEST-EXEC: btest-diff postgresql.cut
+
+@load base/protocols/conn
+@load base/protocols/postgresql