- introduce xlowercase() and allow lowercase() to fail gracefully

- replace all calls to lowercase() with calls to xlowercase()
- in the format string expansion, lowercase() all formats

we will have to reassess all calls to xlowercase() even though it has never
triggered as far as I know, we can probably gracefully fail some of them.
right now we're just keeping former behaviour.

this commit fixes issue reported by Hugo Osvaldo Barrera where a %u format
could lead to a delivery failure (ie: GILLES@openbsd.org should be expanded
to gilles, not GILLES ... only for local deliveries).

ok chl@ on the idea, ok eric@ on the diff

5 files changed, 34 insertions, 16 deletions

diff --git a/usr.sbin/smtpd/aliases.c b/usr.sbin/smtpd/aliases.c
index 7995ecaa1a1..09b6605cab6 100644
--- a/usr.sbin/smtpd/aliases.c
+++ b/usr.sbin/smtpd/aliases.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: aliases.c,v 1.47 2012/04/21 12:45:05 gilles Exp $	*/
+/*	$OpenBSD: aliases.c,v 1.48 2012/07/29 17:21:43 gilles Exp $	*/
 
 /*
  * Copyright (c) 2008 Gilles Chehade <gilles@openbsd.org>
@@ -46,7 +46,7 @@ aliases_exist(objid_t mapid, char *username)
 	struct map_alias *map_alias;
 	char buf[MAX_LOCALPART_SIZE];
 
-	lowercase(buf, username, sizeof(buf));
+	xlowercase(buf, username, sizeof(buf));
 	map_alias = map_lookup(mapid, buf, K_ALIAS);
 	if (map_alias == NULL)
 		return 0;
@@ -69,7 +69,7 @@ aliases_get(objid_t mapid, struct expandtree *expandtree, char *username)
 	char buf[MAX_LOCALPART_SIZE];
 	size_t nbaliases;
 
-	lowercase(buf, username, sizeof(buf));
+	xlowercase(buf, username, sizeof(buf));
 	map_alias = map_lookup(mapid, buf, K_ALIAS);
 	if (map_alias == NULL)
 		return 0;
@@ -99,7 +99,7 @@ aliases_vdomain_exists(objid_t mapid, char *hostname)
 	struct map_virtual *map_virtual;
 	char buf[MAXHOSTNAMELEN];
 
-	lowercase(buf, hostname, sizeof(buf));
+	xlowercase(buf, hostname, sizeof(buf));
 	map_virtual = map_lookup(mapid, buf, K_VIRTUAL);
 	if (map_virtual == NULL)
 		return 0;
@@ -122,7 +122,7 @@ aliases_virtual_exist(objid_t mapid, struct mailaddr *maddr)
 	if (! bsnprintf(buf, sizeof(buf), "%s@%s", maddr->user,
 		maddr->domain))
 		return 0;
-	lowercase(buf, buf, sizeof(buf));
+	xlowercase(buf, buf, sizeof(buf));
 
 	map_virtual = map_lookup(mapid, buf, K_VIRTUAL);
 	if (map_virtual == NULL) {
@@ -152,7 +152,7 @@ aliases_virtual_get(objid_t mapid, struct expandtree *expandtree,
 	if (! bsnprintf(buf, sizeof(buf), "%s@%s", maddr->user,
 		maddr->domain))
 		return 0;
-	lowercase(buf, buf, sizeof(buf));
+	xlowercase(buf, buf, sizeof(buf));
 
 	map_virtual = map_lookup(mapid, buf, K_VIRTUAL);
 	if (map_virtual == NULL) {
diff --git a/usr.sbin/smtpd/lka_session.c b/usr.sbin/smtpd/lka_session.c
index b0b1423ad21..f0eec8e037e 100644
--- a/usr.sbin/smtpd/lka_session.c
+++ b/usr.sbin/smtpd/lka_session.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: lka_session.c,v 1.18 2012/07/29 16:33:01 eric Exp $	*/
+/*	$OpenBSD: lka_session.c,v 1.19 2012/07/29 17:21:43 gilles Exp $	*/
 
 /*
  * Copyright (c) 2011 Gilles Chehade <gilles@openbsd.org>
@@ -94,7 +94,7 @@ lka_session_envelope_expand(struct lka_session *lks, struct envelope *ep)
 			user = ep->dest.user;
 		else
 			user = ep->agent.mda.to.user;
-		lowercase(username, user, sizeof(username));
+		xlowercase(username, user, sizeof(username));
 
 		/* gilles+hackers@ -> gilles@ */
 		if ((tag = strchr(username, '+')) != NULL) {
@@ -505,6 +505,7 @@ lka_session_expand_format(char *buf, size_t len, struct envelope *ep)
 	struct user_backend *ub;
 	struct mta_user u;
 	char lbuffer[MAX_RULEBUFFER_LEN];
+	char tmpbuf[MAX_RULEBUFFER_LEN];
 	
 	bzero(lbuffer, sizeof (lbuffer));
 	pbuf = lbuffer;
@@ -580,6 +581,10 @@ lka_session_expand_format(char *buf, size_t len, struct envelope *ep)
 				goto copy;
 			}
 
+			if (! lowercase(tmpbuf, string, sizeof tmpbuf))
+				return 0;
+			string = tmpbuf;
+			
 			if (digit == 1) {
 				size_t idx = *(tmp - 1) - '0';
 
diff --git a/usr.sbin/smtpd/makemap.c b/usr.sbin/smtpd/makemap.c
index 6b0797839cc..36126b25a68 100644
--- a/usr.sbin/smtpd/makemap.c
+++ b/usr.sbin/smtpd/makemap.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: makemap.c,v 1.32 2011/05/16 21:27:38 jasper Exp $	*/
+/*	$OpenBSD: makemap.c,v 1.33 2012/07/29 17:21:43 gilles Exp $	*/
 
 /*
  * Copyright (c) 2008 Gilles Chehade <gilles@openbsd.org>
@@ -276,7 +276,7 @@ parse_mapentry(char *line, size_t len, size_t lineno)
 			goto bad;
 	}
 	else if (type == T_ALIASES) {
-		lowercase(key.data, key.data, strlen(key.data) + 1);
+		xlowercase(key.data, key.data, strlen(key.data) + 1);
 		if (! make_aliases(&val, valp))
 			goto bad;
 	}
diff --git a/usr.sbin/smtpd/smtpd.h b/usr.sbin/smtpd/smtpd.h
index ac91a836c58..b2b72a90f4c 100644
--- a/usr.sbin/smtpd/smtpd.h
+++ b/usr.sbin/smtpd/smtpd.h
@@ -1,4 +1,4 @@
-/*	$OpenBSD: smtpd.h,v 1.312 2012/07/29 16:33:01 eric Exp $	*/
+/*	$OpenBSD: smtpd.h,v 1.313 2012/07/29 17:21:43 gilles Exp $	*/
 
 /*
  * Copyright (c) 2008 Gilles Chehade <gilles@openbsd.org>
@@ -1183,7 +1183,8 @@ int valid_domainpart(const char *);
 char *ss_to_text(struct sockaddr_storage *);
 char *time_to_text(time_t);
 int secure_file(int, char *, char *, uid_t, int);
-void lowercase(char *, char *, size_t);
+int  lowercase(char *, char *, size_t);
+void xlowercase(char *, char *, size_t);
 void sa_set_port(struct sockaddr *, int);
 u_int64_t generate_uid(void);
 void fdlimit(double);
diff --git a/usr.sbin/smtpd/util.c b/usr.sbin/smtpd/util.c
index 96e8350264e..53b0dd8d884 100644
--- a/usr.sbin/smtpd/util.c
+++ b/usr.sbin/smtpd/util.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: util.c,v 1.66 2012/07/12 08:51:43 chl Exp $	*/
+/*	$OpenBSD: util.c,v 1.67 2012/07/29 17:21:43 gilles Exp $	*/
 
 /*
  * Copyright (c) 2000,2001 Markus Friedl.  All rights reserved.
@@ -711,19 +711,31 @@ addargs(arglist *args, char *fmt, ...)
 	args->list[args->num] = NULL;
 }
 
-void
+int
 lowercase(char *buf, char *s, size_t len)
 {
 	if (len == 0)
-		fatalx("lowercase: len == 0");
+		return 0;
 
 	if (strlcpy(buf, s, len) >= len)
-		fatalx("lowercase: truncation");
+		return 0;
 
 	while (*buf != '\0') {
 		*buf = tolower((int)*buf);
 		buf++;
 	}
+
+	return 1;
+}
+
+void
+xlowercase(char *buf, char *s, size_t len)
+{
+	if (len == 0)
+		fatalx("lowercase: len == 0");
+
+	if (! lowercase(buf, s, len))
+		fatalx("lowercase: truncation");
 }
 
 void