Improve log messages related to pg_hba.conf not matching a connection.

Include details on whether GSS encryption has been activated;
since we added "hostgssenc" type HBA entries, that's relevant info.

Kyotaro Horiguchi and Tom Lane.  Back-patch to v12 where
GSS encryption was introduced.

Discussion: https://postgr.es/m/e5b0b6ed05764324a2f3fe7acfc766d5@smhi.se

src/backend/libpq/auth.c

@@ -401,44 +401,37 @@ ClientAuthentication(Port *port)
 			 */
 			{
 				char		hostinfo[NI_MAXHOST];
+				const char *encryption_state;
 
 				pg_getnameinfo_all(&port->raddr.addr, port->raddr.salen,
 								   hostinfo, sizeof(hostinfo),
 								   NULL, 0,
 								   NI_NUMERICHOST);
 
-				if (am_walsender)
+				encryption_state =
-				{
+#ifdef ENABLE_GSS
+					(port->gss && port->gss->enc) ? _("GSS encryption") :
+#endif
 #ifdef USE_SSL
+					port->ssl_in_use ? _("SSL on") :
+#endif
+					_("SSL off");
+
+				if (am_walsender)
 					ereport(FATAL,
 							(errcode(ERRCODE_INVALID_AUTHORIZATION_SPECIFICATION),
+					/* translator: last %s describes encryption state */
 							 errmsg("pg_hba.conf rejects replication connection for host \"%s\", user \"%s\", %s",
 									hostinfo, port->user_name,
-									port->ssl_in_use ? _("SSL on") : _("SSL off"))));
+									encryption_state)));
-#else
-					ereport(FATAL,
-							(errcode(ERRCODE_INVALID_AUTHORIZATION_SPECIFICATION),
-							 errmsg("pg_hba.conf rejects replication connection for host \"%s\", user \"%s\"",
-									hostinfo, port->user_name)));
-#endif
-				}
 				else
-				{
-#ifdef USE_SSL
 					ereport(FATAL,
 							(errcode(ERRCODE_INVALID_AUTHORIZATION_SPECIFICATION),
+					/* translator: last %s describes encryption state */
 							 errmsg("pg_hba.conf rejects connection for host \"%s\", user \"%s\", database \"%s\", %s",
 									hostinfo, port->user_name,
 									port->database_name,
-									port->ssl_in_use ? _("SSL on") : _("SSL off"))));
+									encryption_state)));
-#else
-					ereport(FATAL,
-							(errcode(ERRCODE_INVALID_AUTHORIZATION_SPECIFICATION),
-							 errmsg("pg_hba.conf rejects connection for host \"%s\", user \"%s\", database \"%s\"",
-									hostinfo, port->user_name,
-									port->database_name)));
-#endif
-				}
 				break;
 			}
 
@@ -454,12 +447,22 @@ ClientAuthentication(Port *port)
 			 */
 			{
 				char		hostinfo[NI_MAXHOST];
+				const char *encryption_state;
 
 				pg_getnameinfo_all(&port->raddr.addr, port->raddr.salen,
 								   hostinfo, sizeof(hostinfo),
 								   NULL, 0,
 								   NI_NUMERICHOST);
 
+				encryption_state =
+#ifdef ENABLE_GSS
+					(port->gss && port->gss->enc) ? _("GSS encryption") :
+#endif
+#ifdef USE_SSL
+					port->ssl_in_use ? _("SSL on") :
+#endif
+					_("SSL off");
+
 #define HOSTNAME_LOOKUP_DETAIL(port) \
 				(port->remote_hostname ? \
 				 (port->remote_hostname_resolv == +1 ? \
@@ -482,41 +485,22 @@ ClientAuthentication(Port *port)
 					0))
 
 				if (am_walsender)
-				{
-#ifdef USE_SSL
 					ereport(FATAL,
 							(errcode(ERRCODE_INVALID_AUTHORIZATION_SPECIFICATION),
+					/* translator: last %s describes encryption state */
 							 errmsg("no pg_hba.conf entry for replication connection from host \"%s\", user \"%s\", %s",
 									hostinfo, port->user_name,
-									port->ssl_in_use ? _("SSL on") : _("SSL off")),
+									encryption_state),
 							 HOSTNAME_LOOKUP_DETAIL(port)));
-#else
-					ereport(FATAL,
-							(errcode(ERRCODE_INVALID_AUTHORIZATION_SPECIFICATION),
-							 errmsg("no pg_hba.conf entry for replication connection from host \"%s\", user \"%s\"",
-									hostinfo, port->user_name),
-							 HOSTNAME_LOOKUP_DETAIL(port)));
-#endif
-				}
 				else
-				{
-#ifdef USE_SSL
 					ereport(FATAL,
 							(errcode(ERRCODE_INVALID_AUTHORIZATION_SPECIFICATION),
+					/* translator: last %s describes encryption state */
 							 errmsg("no pg_hba.conf entry for host \"%s\", user \"%s\", database \"%s\", %s",
 									hostinfo, port->user_name,
 									port->database_name,
-									port->ssl_in_use ? _("SSL on") : _("SSL off")),
+									encryption_state),
 							 HOSTNAME_LOOKUP_DETAIL(port)));
-#else
-					ereport(FATAL,
-							(errcode(ERRCODE_INVALID_AUTHORIZATION_SPECIFICATION),
-							 errmsg("no pg_hba.conf entry for host \"%s\", user \"%s\", database \"%s\"",
-									hostinfo, port->user_name,
-									port->database_name),
-							 HOSTNAME_LOOKUP_DETAIL(port)));
-#endif
-				}
 				break;
 			}