- 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, 16 insertions, 4 deletions

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