Add freezero support

crypto/CMakeLists.txt

@@ -681,6 +681,11 @@ if(NOT HAVE_ASPRINTF)
 	set(EXTRA_EXPORT ${EXTRA_EXPORT} vasprintf)
 endif()
 
+if(NOT HAVE_FREEZERO)
+	set(CRYPTO_SRC ${CRYPTO_SRC} compat/freezero.c)
+	set(EXTRA_EXPORT ${EXTRA_EXPORT} freezero)
+endif()
+
 if(NOT HAVE_GETPAGESIZE)
 	set(CRYPTO_SRC ${CRYPTO_SRC} compat/getpagesize.c)
 endif()

crypto/Makefile.am

@@ -84,6 +84,10 @@ if !HAVE_ASPRINTF
 libcompat_la_SOURCES += compat/bsd-asprintf.c
 endif
 
+if !HAVE_FREEZERO
+libcompat_la_SOURCES += compat/freezero.c
+endif
+
 if !HAVE_GETPAGESIZE
 libcompat_la_SOURCES += compat/getpagesize.c
 endif

crypto/compat/freezero.c

@@ -0,0 +1,13 @@
+#include <string.h>
+#include <stdlib.h>
+
+void
+freezero(void *ptr, size_t sz)
+{
+	/* This is legal. */
+	if (ptr == NULL)
+		return;
+
+	explicit_bzero(ptr, sz);
+	free(ptr);
+}