Add a utils.h file that contains common functions
The new header contains common information across various mbed TLS
modules and avoids code duplication. To start, utils.h currently only
contains the mbedtls_zeroize() function.
diff --git a/library/CMakeLists.txt b/library/CMakeLists.txt
index 7742c22..24a2484 100644
--- a/library/CMakeLists.txt
+++ b/library/CMakeLists.txt
@@ -57,6 +57,7 @@
version.c
version_features.c
xtea.c
+ utils.c
)
set(src_x509
diff --git a/library/Makefile b/library/Makefile
index 0333815..46dce4e 100644
--- a/library/Makefile
+++ b/library/Makefile
@@ -65,7 +65,8 @@
ripemd160.o rsa_internal.o rsa.o \
sha1.o sha256.o sha512.o \
threading.o timing.o version.o \
- version_features.o xtea.o
+ version_features.o xtea.o \
+ utils.o
OBJS_X509= certs.o pkcs11.o x509.o \
x509_create.o x509_crl.o x509_crt.o \
diff --git a/library/utils.c b/library/utils.c
new file mode 100644
index 0000000..f943cb1
--- /dev/null
+++ b/library/utils.c
@@ -0,0 +1,33 @@
+/*
+ * mbedtls utility functions
+ *
+ * Copyright (C) 2017, ARM Limited, All Rights Reserved
+ * SPDX-License-Identifier: Apache-2.0
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License"); you may
+ * not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+ * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ *
+ * This file is part of mbed TLS (https://tls.mbed.org)
+ */
+
+#include "mbedtls/utils.h"
+
+#include <stddef.h>
+
+/* This implementation should never be optimized out by the compiler */
+void mbedtls_zeroize( void *buf, size_t len )
+{
+ volatile unsigned char *p = (unsigned char *)buf;
+
+ while( len-- )
+ *p++ = 0;
+}