Implement memset_s and improve free_secure

1 files changed, 48 insertions, 0 deletions

diff --git a/src/memset_s.c b/src/memset_s.c
new file mode 100644
index 0000000..deda5d7
--- /dev/null
+++ b/src/memset_s.c
@@ -0,0 +1,48 @@
+/* memset_s.c
+ *
+ * Copyright 2024 axtlos <axtlos@disroot.org>
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Lesser General Public License as published by
+ * the Free Software Foundation, version 3.
+ *
+ * This program 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 Lesser General Public License
+ * along with this program. If not, see <https://www.gnu.org/licenses/>.
+ *
+ * SPDX-License-Identifier: LGPL-3.0-only
+ */
+
+
+#define __STDC_WANT_LIB_EXT1__ 1
+#include "extlib.h"
+#include <errno.h>
+
+
+errno_t
+memset_s(void *s, rsize_t smax, int c, rsize_t n)
+{
+  volatile unsigned char *dest = (unsigned char *) s;
+  errno_t ret = EINVAL;
+  rsize_t limit = n < smax ? n : smax;
+
+  if (!s)
+    throw_constraint_handler_s("memset_s: s = NULL", ret);
+  else if (n > RSIZE_MAX)
+    throw_constraint_handler_s("memset_s: n > RSIZE_MAX", ret);
+  else if (smax > RSIZE_MAX)
+    throw_constraint_handler_s("memset_s: smax > RSIZE_MAX", ret);
+  else if (n > smax)
+    throw_constraint_handler_s("memset_s: n > smax", ret);
+  else {
+    while (limit > 0)
+      dest[--limit] = (unsigned char)c;
+    ret = 0;
+  }
+  return ret;
+}
+