Added a minimal string library to assist in safer ASN.1 parsing

1 files changed, 55 insertions, 0 deletions

diff --git a/lib/gnutls_str.c b/lib/gnutls_str.c
new file mode 100644
index 0000000000..a0fd25ea61
--- /dev/null
+++ b/lib/gnutls_str.c
@@ -0,0 +1,55 @@
+/*
+ *      Copyright (C) 2002 Nikos Mavroyanopoulos
+ *
+ * This file is part of GNUTLS.
+ *
+ * GNUTLS is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * GNUTLS is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA
+ */
+
+#include <gnutls_int.h>
+#include <gnutls_errors.h>
+#include <gnutls_num.h>
+
+/* These function are like strcat, strcpy. They only
+ * do bound checking (they shouldn't cause buffer overruns),
+ * and they always produce null terminated strings.
+ */
+void _gnutls_str_cat( char* dest, size_t dest_tot_size, const char* src) {
+size_t str_size = strlen(src);
+size_t dest_size = strlen(dest);
+
+	if ( dest_tot_size - dest_size > str_size) {
+		strcat( dest, src);
+	} else {
+		if ( dest_tot_size - dest_size > 0) {
+			strncat( dest, src, (dest_tot_size - dest_size) -1);
+			dest[dest_tot_size-1] = 0;
+		}
+	}
+}
+
+void _gnutls_str_cpy( char* dest, size_t dest_tot_size, const char* src) {
+size_t str_size = strlen(src);
+
+	if ( dest_tot_size > str_size) {
+		strcpy( dest, src);
+	} else {
+		if ( dest_tot_size > 0) {
+			strncpy( dest, src, (dest_tot_size) -1);
+			dest[dest_tot_size-1] = 0;
+		}
+	}
+}
+