added bounds checking via secure strl*() routines

1 files changed, 50 insertions, 0 deletions

diff --git a/strlcpy.h b/strlcpy.h
new file mode 100644
index 0000000..6301674
--- /dev/null
+++ b/strlcpy.h
@@ -0,0 +1,50 @@
+/*	$OpenBSD: strlcpy.c,v 1.13 2015/08/31 02:53:57 guenther Exp $	*/
+
+/*
+ * Copyright (c) 1998, 2015 Todd C. Miller <Todd.Miller@courtesan.com>
+ *
+ * Permission to use, copy, modify, and distribute this software for any
+ * purpose with or without fee is hereby granted, provided that the above
+ * copyright notice and this permission notice appear in all copies.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
+ * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
+ * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
+ * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+ * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
+ * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
+ * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+ */
+
+#include <sys/types.h>
+#include <string.h>
+
+/*
+ * Copy string src to buffer dst of size dsize.  At most dsize-1
+ * chars will be copied.  Always NUL terminates (unless dsize == 0).
+ * Returns strlen(src); if retval >= dsize, truncation occurred.
+ */
+size_t
+strlcpy(char *dst, const char *src, size_t dsize)
+{
+	const char *osrc = src;
+	size_t nleft = dsize;
+
+	/* Copy as many bytes as will fit. */
+	if (nleft != 0) {
+		while (--nleft != 0) {
+			if ((*dst++ = *src++) == '\0')
+				break;
+		}
+	}
+
+	/* Not enough room in dst, add NUL and traverse rest of src. */
+	if (nleft == 0) {
+		if (dsize != 0)
+			*dst = '\0';		/* NUL-terminate dst */
+		while (*src++)
+			;
+	}
+
+	return(src - osrc - 1);	/* count does not include NUL */
+}