postgrespro.git / summary / log / commit / refs

commit    c5e1df951d9d70ab7d53ce47caaf73f3b2d6b1e1
Author:   Peter Eisentraut <peter@eisentraut.org>
Date:     Wed Oct 30 10:01:44 2019 +0000

    Remove one use of IDENT_USERNAME_MAX
    
    IDENT_USERNAME_MAX is the maximum length of the information returned
    by an ident server, per RFC 1413.  Using it as the buffer size in peer
    authentication is inappropriate.  It was done here because of the
    historical relationship between peer and ident authentication.  To
    reduce confusion between the two authenticaton methods and disentangle
    their code, use a dynamically allocated buffer instead.
    
    Discussion: https://www.postgresql.org/message-id/flat/c798fba5-8b71-4f27-c78e-37714037ea31%402ndquadrant.com


 src/backend/libpq/auth.c | 14 ++++++++++----
 1 file changed, 10 insertions(+), 4 deletions(-)

diff --git a/src/backend/libpq/auth.c b/src/backend/libpq/auth.c
index 58a44adeb7..d28271c1d8 100644
--- a/src/backend/libpq/auth.c
+++ b/src/backend/libpq/auth.c
@@ -65,7 +65,7 @@ static int	CheckSCRAMAuth(Port *port, char *shadow_pass, char **logdetail);
  * Ident authentication
  *----------------------------------------------------------------
  */
-/* Max size of username ident server can return */
+/* Max size of username ident server can return (per RFC 1413) */
 #define IDENT_USERNAME_MAX 512
 
 /* Standard TCP port number for Ident service.  Assigned by IANA */
@@ -1990,10 +1990,11 @@ ident_inet_done:
 static int
 auth_peer(hbaPort *port)
 {
-	char		ident_user[IDENT_USERNAME_MAX + 1];
 	uid_t		uid;
 	gid_t		gid;
 	struct passwd *pw;
+	char	   *peer_user;
+	int			ret;
 
 	if (getpeereid(port->sock, &uid, &gid) != 0)
 	{
@@ -2022,9 +2023,14 @@ auth_peer(hbaPort *port)
 		return STATUS_ERROR;
 	}
 
-	strlcpy(ident_user, pw->pw_name, IDENT_USERNAME_MAX + 1);
+	/* Make a copy of static getpw*() result area. */
+	peer_user = pstrdup(pw->pw_name);
+
+	ret = check_usermap(port->hba->usermap, port->user_name, peer_user, false);
 
-	return check_usermap(port->hba->usermap, port->user_name, ident_user, false);
+	pfree(peer_user);
+
+	return ret;
 }
 #endif							/* HAVE_UNIX_SOCKETS */
 


[parent: 5cc1e64fb6f5]