rewrite convtime() to use a isdigit-scanner and strtonum() instead of

strange strtoul can might be fooled by garage characters.
passes regress/usr.bin/ssh/unittests/misc
ok djm

diff --git a/usr.bin/ssh/misc.c b/usr.bin/ssh/misc.c
index 7ec927d..1692a05 100644 (file)
--- a/usr.bin/ssh/misc.c
+++ b/usr.bin/ssh/misc.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: misc.c,v 1.190 2024/03/04 02:16:11 djm Exp $ */
+/* $OpenBSD: misc.c,v 1.191 2024/04/02 09:52:14 deraadt Exp $ */
 /*
  * Copyright (c) 2000 Markus Friedl.  All rights reserved.
  * Copyright (c) 2005-2020 Damien Miller.  All rights reserved.
@@ -511,6 +511,14 @@ a2tun(const char *s, int *remote)
 #define DAYS           (HOURS * 24)
 #define WEEKS          (DAYS * 7)
 
+static char *
+scandigits(char *s)
+{
+       while (isdigit((unsigned char)*s))
+               s++;
+       return s;
+}
+
 /*
  * Convert a time string into seconds; format is
  * a sequence of:
@@ -535,28 +543,31 @@ a2tun(const char *s, int *remote)
 int
 convtime(const char *s)
 {
-       long total, secs, multiplier;
-       const char *p;
-       char *endp;
-
-       errno = 0;
-       total = 0;
-       p = s;
+       int secs, total = 0, multiplier;
+       char *p, *os, *np, c;
+       const char *errstr;
 
-       if (p == NULL || *p == '\0')
+       if (s == NULL || *s == '\0')
+               return -1;
+       p = os = strdup(s);     /* deal with const */
+       if (os == NULL)
                return -1;
 
        while (*p) {
-               secs = strtol(p, &endp, 10);
-               if (p == endp ||
-                   (errno == ERANGE && (secs == INT_MIN || secs == INT_MAX)) ||
-                   secs < 0)
-                       return -1;
+               np = scandigits(p);
+               if (np) {
+                       c = *np;
+                       *np = '\0';
+               }
+               secs = (int)strtonum(p, 0, INT_MAX, &errstr);
+               if (errstr)
+                       goto fail;
+               *np = c;
 
                multiplier = 1;
-               switch (*endp++) {
+               switch (c) {
                case '\0':
-                       endp--;
+                       np--;   /* back up */
                        break;
                case 's':
                case 'S':
@@ -578,20 +589,23 @@ convtime(const char *s)
                        multiplier = WEEKS;
                        break;
                default:
-                       return -1;
+                       goto fail;
                }
                if (secs > INT_MAX / multiplier)
-                       return -1;
+                       goto fail;
                secs *= multiplier;
                if  (total > INT_MAX - secs)
-                       return -1;
+                       goto fail;
                total += secs;
                if (total < 0)
-                       return -1;
-               p = endp;
+                       goto fail;
+               p = ++np;
        }
-
+       free(os);
        return total;
+fail:
+       free(os);
+       return -1;
 }
 
 #define TF_BUFS        8