Change libpq's internal uses of PQhost() to inspect host field directly.

tglsfdc · tglsfdc · commit 24986c95520e · 2018-08-03T12:12:10.000-04:00
Commit 1944cdc changed PQhost() to return the hostaddr value when that is specified and host isn't. This is a good idea in general, but fe-auth.c and related files contain PQhost() calls for which it isn't. Specifically, when we compare SSL certificates or other server identity information to the host field, we do not want to use hostaddr instead; that's not what's documented, that's not what happened pre-v10, and it doesn't seem like a good idea. Instead, we can just look at connhost[].host directly. This does what we want in v10 and up; in particular, if neither host nor hostaddr were given, the host field will be replaced with the default host name. That seems useful, and it's likely the reason that these places were coded to call PQhost() originally (since pre-v10, the stored field was not replaced with the default). Back-patch to v10, as 1944cdc (just) was. Discussion: https://postgr.es/m/23287.1533227021@sss.pgh.pa.us
diff --git a/src/interfaces/libpq/fe-auth.c b/src/interfaces/libpq/fe-auth.c
@@ -199,7 +199,7 @@ pg_GSS_startup(PGconn *conn, int payloadlen)
 				min_stat;
 	int			maxlen;
 	gss_buffer_desc temp_gbuf;
-	char	   *host = PQhost(conn);
+	char	   *host = conn->connhost[conn->whichhost].host;
 
 	if (!(host && host[0] != '\0'))
 	{
@@ -414,7 +414,7 @@ pg_SSPI_startup(PGconn *conn, int use_negotiate, int payloadlen)
 {
 	SECURITY_STATUS r;
 	TimeStamp	expire;
-	char	   *host = PQhost(conn);
+	char	   *host = conn->connhost[conn->whichhost].host;
 
 	if (conn->sspictx)
 	{
diff --git a/src/interfaces/libpq/fe-secure-common.c b/src/interfaces/libpq/fe-secure-common.c
@@ -88,10 +88,17 @@ pq_verify_peer_name_matches_certificate_name(PGconn *conn,
 {
 	char	   *name;
 	int			result;
-	char	   *host = PQhost(conn);
+	char	   *host = conn->connhost[conn->whichhost].host;
 
 	*store_name = NULL;
 
+	if (!(host && host[0] != '\0'))
+	{
+		printfPQExpBuffer(&conn->errorMessage,
+						  libpq_gettext("host name must be specified\n"));
+		return -1;
+	}
+
 	/*
 	 * There is no guarantee the string returned from the certificate is
 	 * NULL-terminated, so make a copy that is.
@@ -145,7 +152,7 @@ pq_verify_peer_name_matches_certificate_name(PGconn *conn,
 bool
 pq_verify_peer_name_matches_certificate(PGconn *conn)
 {
-	char	   *host = PQhost(conn);
+	char	   *host = conn->connhost[conn->whichhost].host;
 	int			rc;
 	int			names_examined = 0;
 	char	   *first_name = NULL;

Original file line number	Diff line number	Diff line change
`@@ -199,7 +199,7 @@ pg_GSS_startup(PGconn *conn, int payloadlen)`
`199`	`199`	`min_stat;`
`200`	`200`	`int maxlen;`
`201`	`201`	`gss_buffer_desc temp_gbuf;`
`202`		`- char *host = PQhost(conn);`
	`202`	`+ char *host = conn->connhost[conn->whichhost].host;`
`203`	`203`
`204`	`204`	`if (!(host && host[0] != '\0'))`
`205`	`205`	`{`
`@@ -414,7 +414,7 @@ pg_SSPI_startup(PGconn *conn, int use_negotiate, int payloadlen)`
`414`	`414`	`{`
`415`	`415`	`SECURITY_STATUS r;`
`416`	`416`	`TimeStamp expire;`
`417`		`- char *host = PQhost(conn);`
	`417`	`+ char *host = conn->connhost[conn->whichhost].host;`
`418`	`418`
`419`	`419`	`if (conn->sspictx)`
`420`	`420`	`{`