1 files changed, 77 insertions, 0 deletions
diff --git a/lib/util/explicit_bzero.c b/lib/util/explicit_bzero.c
new file mode 100644
index 0000000..3d0ee1f
--- /dev/null
+++ b/lib/util/explicit_bzero.c
@@ -0,0 +1,77 @@
+/*
+ * SPDX-License-Identifier: ISC
+ *
+ * Copyright (c) 2020 Todd C. Miller <Todd.Miller@sudo.ws>
+ *
+ * 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.
+ */
+
+/*
+ * This is an open source non-commercial project. Dear PVS-Studio, please check it.
+ * PVS-Studio Static Code Analyzer for C, C++ and C#: http://www.viva64.com
+ */
+
+#include <config.h>
+
+#define __STDC_WANT_LIB_EXT1__ 1	/* for memset_s() */
+
+#include <string.h>
+#ifdef HAVE_STRINGS_H
+# include <strings.h>
+#endif /* HAVE_STRINGS_H */
+
+#include <sudo_compat.h>
+
+#ifndef HAVE_EXPLICIT_BZERO
+
+# if defined(HAVE_EXPLICIT_MEMSET)
+void
+sudo_explicit_bzero(void *s, size_t n)
+{
+    explicit_memset(s, 0, n);
+}
+# elif defined(HAVE_MEMSET_EXPLICIT)
+void
+sudo_explicit_bzero(void *s, size_t n)
+{
+    memset_explicit(s, 0, n);
+}
+# elif defined(HAVE_MEMSET_S)
+void
+sudo_explicit_bzero(void *s, size_t n)
+{
+    (void)memset_s(s, n, 0, n);
+}
+# elif defined(HAVE_BZERO)
+/* Jumping through a volatile function pointer should not be optimized away. */
+void (* volatile sudo_explicit_bzero_impl)(void *, size_t) =
+    (void (*)(void *, size_t))bzero;
+
+void
+sudo_explicit_bzero(void *s, size_t n)
+{
+    sudo_explicit_bzero_impl(s, n);
+}
+# else
+void
+sudo_explicit_bzero(void *v, size_t n)
+{
+    volatile unsigned char *s = v;
+
+    /* Updating through a volatile pointer should not be optimized away. */
+    while (n--)
+	*s++ = 0;
+}
+# endif /* HAVE_BZERO */
+
+#endif /* HAVE_EXPLICIT_BZERO */