Rewrite tohexstr() to use the common idiom of converting a byte

string to hex nybble by nybble.  This avoids using the return value
of snprintf() unchecked.  OK deraadt@

diff --git a/usr.sbin/snmpd/snmpd.c b/usr.sbin/snmpd/snmpd.c
index 96caeea..ba5661a 100644 (file)
--- a/usr.sbin/snmpd/snmpd.c
+++ b/usr.sbin/snmpd/snmpd.c
@@ -1,4 +1,4 @@
-/*     $OpenBSD: snmpd.c,v 1.35 2017/01/09 14:49:22 reyk Exp $ */
+/*     $OpenBSD: snmpd.c,v 1.36 2017/04/04 02:37:15 millert Exp $      */
 
 /*
  * Copyright (c) 2007, 2008, 2012 Reyk Floeter <reyk@openbsd.org>
@@ -375,16 +375,19 @@ snmpd_engine_time(void)
 }
 
 char *
-tohexstr(u_int8_t *str, int len)
+tohexstr(u_int8_t *bstr, int len)
 {
 #define MAXHEXSTRLEN           256
        static char hstr[2 * MAXHEXSTRLEN + 1];
-       char *r = hstr;
+       static const char hex[] = "0123456789abcdef";
+       int i;
 
        if (len > MAXHEXSTRLEN)
                len = MAXHEXSTRLEN;     /* truncate */
-       while (len-- > 0)
-               r += snprintf(r, len * 2, "%0*x", 2, *str++);
-       *r = '\0';
+       for (i = 0; i < len; i++) {
+               hstr[i + i] = hex[bstr[i] >> 4];
+               hstr[i + i + 1] = hex[bstr[i] & 0x0f];
+       }
+       hstr[i + i] = '\0';
        return hstr;
 }