Replace atoi and strtol conversions for integer arguments to config

keywords with a checking wrapper around strtonum.  This will prevent
and flag invalid and negative arguments to these keywords.  ok djm@

4 files changed, 27 insertions, 18 deletions

diff --git a/usr.bin/ssh/misc.c b/usr.bin/ssh/misc.c
index 547f2bd3226..746d95b4917 100644
--- a/usr.bin/ssh/misc.c
+++ b/usr.bin/ssh/misc.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: misc.c,v 1.119 2017/11/25 06:46:22 dtucker Exp $ */
+/* $OpenBSD: misc.c,v 1.120 2017/12/05 23:59:47 dtucker Exp $ */
 /*
  * Copyright (c) 2000 Markus Friedl.  All rights reserved.
  * Copyright (c) 2005,2006 Damien Miller.  All rights reserved.
@@ -2026,3 +2026,17 @@ bad:
 		*errstr = errbuf;
 	return 0;
 }
+
+const char *
+atoi_err(const char *nptr, int *val)
+{
+	const char *errstr = NULL;
+	long long num;
+
+	if (nptr == NULL || *nptr == '\0')
+		return "missing";
+	num = strtonum(nptr, 0, INT_MAX, &errstr);
+	if (errstr == NULL)
+		*val = (int)num;
+	return errstr;
+}
diff --git a/usr.bin/ssh/misc.h b/usr.bin/ssh/misc.h
index 8e24d5c4484..a81a124e624 100644
--- a/usr.bin/ssh/misc.h
+++ b/usr.bin/ssh/misc.h
@@ -1,4 +1,4 @@
-/* $OpenBSD: misc.h,v 1.68 2017/11/25 06:46:22 dtucker Exp $ */
+/* $OpenBSD: misc.h,v 1.69 2017/12/05 23:59:47 dtucker Exp $ */
 
 /*
  * Author: Tatu Ylonen <ylo@cs.hut.fi>
@@ -74,6 +74,7 @@ double	 monotime_double(void);
 void	 lowercase(char *s);
 int	 unix_listener(const char *, int, int);
 int	 valid_domain(char *, int, const char **);
+const char *atoi_err(const char *, int *);
 
 struct passwd *pwcopy(struct passwd *);
 const char *ssh_gai_strerror(int);
diff --git a/usr.bin/ssh/readconf.c b/usr.bin/ssh/readconf.c
index e3a7e110d7a..59f0032c523 100644
--- a/usr.bin/ssh/readconf.c
+++ b/usr.bin/ssh/readconf.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: readconf.c,v 1.280 2017/10/21 23:06:24 millert Exp $ */
+/* $OpenBSD: readconf.c,v 1.281 2017/12/05 23:59:47 dtucker Exp $ */
 /*
  * Author: Tatu Ylonen <ylo@cs.hut.fi>
  * Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland
@@ -802,6 +802,7 @@ process_config_line_depth(Options *options, struct passwd *pw, const char *host,
 	const struct multistate *multistate_ptr;
 	struct allowed_cname *cname;
 	glob_t gl;
+	const char *errstr;
 
 	if (activep == NULL) { /* We are processing a command line directive */
 		cmdline = 1;
@@ -1116,15 +1117,9 @@ parse_command:
 		intptr = &options->port;
 parse_int:
 		arg = strdelim(&s);
-		if (!arg || *arg == '\0')
-			fatal("%.200s line %d: Missing argument.", filename, linenum);
-		if (arg[0] < '0' || arg[0] > '9')
-			fatal("%.200s line %d: Bad number.", filename, linenum);
-
-		/* Octal, decimal, or hex format? */
-		value = strtol(arg, &endofnumber, 0);
-		if (arg == endofnumber)
-			fatal("%.200s line %d: Bad number.", filename, linenum);
+		if ((errstr = atoi_err(arg, &value)) != NULL)
+			fatal("%s line %d: integer value %s.",
+			    filename, linenum, errstr);
 		if (*activep && *intptr == -1)
 			*intptr = value;
 		break;
@@ -1519,7 +1514,6 @@ parse_keytypes:
 	case oCanonicalDomains:
 		value = options->num_canonical_domains != 0;
 		while ((arg = strdelim(&s)) != NULL && *arg != '\0') {
-			const char *errstr;
 			if (!valid_domain(arg, 1, &errstr)) {
 				fatal("%s line %d: %s", filename, linenum,
 				    errstr);
diff --git a/usr.bin/ssh/servconf.c b/usr.bin/ssh/servconf.c
index e56dd51cf80..388bc322757 100644
--- a/usr.bin/ssh/servconf.c
+++ b/usr.bin/ssh/servconf.c
@@ -1,5 +1,5 @@
 
-/* $OpenBSD: servconf.c,v 1.321 2017/12/05 23:56:07 dtucker Exp $ */
+/* $OpenBSD: servconf.c,v 1.322 2017/12/05 23:59:47 dtucker Exp $ */
 /*
  * Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland
  *                    All rights reserved
@@ -1095,6 +1095,7 @@ process_server_config_line(ServerOptions *options, char *line,
 	size_t len;
 	long long val64;
 	const struct multistate *multistate_ptr;
+	const char *errstr;
 
 	/* Strip trailing whitespace. Allow \f (form feed) at EOL only */
 	if ((len = strlen(line)) == 0)
@@ -1378,10 +1379,9 @@ process_server_config_line(ServerOptions *options, char *line,
 		intptr = &options->x11_display_offset;
  parse_int:
 		arg = strdelim(&cp);
-		if (!arg || *arg == '\0')
-			fatal("%s line %d: missing integer value.",
-			    filename, linenum);
-		value = atoi(arg);
+		if ((errstr = atoi_err(arg, &value)) != NULL)
+			fatal("%s line %d: integer value %s.",
+			    filename, linenum, errstr);
 		if (*activep && *intptr == -1)
 			*intptr = value;
 		break;