add valid_message_id() and valid_message_uid() which test that a message id

and uid do not look wrong. this was not needed earlier because we only deal
with message id's coming from trusted sources, but smtpctl will soon have a
new feature which requires us to deal with user provided message id's.

2 files changed, 51 insertions, 2 deletions

diff --git a/usr.sbin/smtpd/smtpd.h b/usr.sbin/smtpd/smtpd.h
index 805beb48dd2..22b007aa6b5 100644
--- a/usr.sbin/smtpd/smtpd.h
+++ b/usr.sbin/smtpd/smtpd.h
@@ -1,4 +1,4 @@
-/*	$OpenBSD: smtpd.h,v 1.75 2009/02/22 11:59:12 jacekm Exp $	*/
+/*	$OpenBSD: smtpd.h,v 1.76 2009/02/23 22:59:40 gilles Exp $	*/
 
 /*
  * Copyright (c) 2008 Gilles Chehade <gilles@openbsd.org>
@@ -901,3 +901,5 @@ int		 recipient_to_path(struct path *, char *);
 int		 valid_localpart(char *);
 int		 valid_domainpart(char *);
 char		*ss_to_text(struct sockaddr_storage *);
+int		 valid_message_id(char *);
+int		 valid_message_uid(char *);
diff --git a/usr.sbin/smtpd/util.c b/usr.sbin/smtpd/util.c
index 03e4b38c685..803b1bf821e 100644
--- a/usr.sbin/smtpd/util.c
+++ b/usr.sbin/smtpd/util.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: util.c,v 1.13 2009/02/22 11:59:12 jacekm Exp $	*/
+/*	$OpenBSD: util.c,v 1.14 2009/02/23 22:59:40 gilles Exp $	*/
 
 /*
  * Copyright (c) 2008 Gilles Chehade <gilles@openbsd.org>
@@ -211,3 +211,50 @@ ss_to_text(struct sockaddr_storage *ss)
 
 	return (buf);
 }
+
+int
+valid_message_id(char *mid)
+{
+	u_int8_t cnt;
+
+	/* [0-9]{10}\.[a-zA-Z0-9]{16} */
+	for (cnt = 0; cnt < 10; ++cnt, ++mid)
+		if (! isdigit((int)*mid))
+			return 0;
+
+	if (*mid++ != '.')
+		return 0;
+
+	for (cnt = 0; cnt < 16; ++cnt, ++mid)
+		if (! isalnum((int)*mid))
+			return 0;
+
+	return (*mid == '\0');
+}
+
+int
+valid_message_uid(char *muid)
+{
+	u_int8_t cnt;
+
+	/* [0-9]{10}\.[a-zA-Z0-9]{16}\.[0-9]{0,} */
+	for (cnt = 0; cnt < 10; ++cnt, ++muid)
+		if (! isdigit((int)*muid))
+			return 0;
+
+	if (*muid++ != '.')
+		return 0;
+
+	for (cnt = 0; cnt < 16; ++cnt, ++muid)
+		if (! isalnum((int)*muid))
+			return 0;
+
+	if (*muid++ != '.')
+		return 0;
+
+	for (cnt = 0; *muid != '\0'; ++cnt, ++muid)
+		if (! isdigit(*muid))
+			return 0;
+
+	return (cnt != 0);
+}