- 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

1 files changed, 7 insertions, 2 deletions

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';