Introduce MBEDTLS_PRIVATE macro.

Public structs members are considered private and should not
be used by users application.

MBEDTLS_PRIVATE(member) macro is intended to clearly indicate
which members are private.

Signed-off-by: Mateusz Starzyk <mateusz.starzyk@mobica.com>

include/mbedtls/private_access.h

@@ -0,0 +1,32 @@
+ /**
+ * \file private_access.h
+ *
+ * \brief Macro wrapper for struct's memebrs.
+ */
+/*
+ *  Copyright The Mbed TLS Contributors
+ *  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.
+ */
+
+#ifndef MBEDTLS_PRIVATE_ACCESS_H
+#define MBEDTLS_PRIVATE_ACCESS_H
+
+#ifndef MBEDTLS_ALLOW_PRIVATE_ACCESS
+#define MBEDTLS_PRIVATE(member) private_##member
+#else
+#define MBEDTLS_PRIVATE(member) member
+#endif
+
+#endif /* MBEDTLS_PRIVATE_ACCESS_H */

library/common.h

@@ -50,4 +50,11 @@
 #define MBEDTLS_STATIC_TESTABLE static
 #endif
 
+/** Allow library to access it's structs' private members.
+ *
+ * Although structs defined in header files are publicly available,
+ * their members are private and should not be accessed by the user.
+ */
+#define MBEDTLS_ALLOW_PRIVATE_ACCESS
+
 #endif /* MBEDTLS_LIBRARY_COMMON_H */

library/psa_crypto_driver_wrappers.c

@@ -19,6 +19,7 @@
  *  limitations under the License.
  */
 
+#include "common.h"
 #include "psa_crypto_aead.h"
 #include "psa_crypto_cipher.h"
 #include "psa_crypto_core.h"

tests/include/test/helpers.h

@@ -25,6 +25,8 @@
 #ifndef TEST_HELPERS_H
 #define TEST_HELPERS_H
 
+#define MBEDTLS_ALLOW_PRIVATE_ACCESS
+
 #if !defined(MBEDTLS_CONFIG_FILE)
 #include "mbedtls/config.h"
 #else

tests/src/drivers/test_driver_aead.c

@@ -23,6 +23,8 @@
 #include MBEDTLS_CONFIG_FILE
 #endif
 
+#include <test/helpers.h>
+
 #if defined(MBEDTLS_PSA_CRYPTO_DRIVERS) && defined(PSA_CRYPTO_DRIVER_TEST)
 #include "psa_crypto_aead.h"
 

tests/src/drivers/test_driver_cipher.c

@@ -24,6 +24,8 @@
 #include MBEDTLS_CONFIG_FILE
 #endif
 
+#include <test/helpers.h>
+
 #if defined(MBEDTLS_PSA_CRYPTO_DRIVERS) && defined(PSA_CRYPTO_DRIVER_TEST)
 #include "psa/crypto.h"
 #include "psa_crypto_cipher.h"

tests/src/drivers/test_driver_signature.c

@@ -25,6 +25,8 @@
 #include MBEDTLS_CONFIG_FILE
 #endif
 
+#include <test/helpers.h>
+
 #if defined(MBEDTLS_PSA_CRYPTO_DRIVERS) && defined(PSA_CRYPTO_DRIVER_TEST)
 #include "psa/crypto.h"
 #include "psa_crypto_core.h"

tests/suites/helpers.function

@@ -2,6 +2,8 @@
 /*----------------------------------------------------------------------------*/
 /* Headers */
 
+#define MBEDTLS_ALLOW_PRIVATE_ACCESS
+
 #include <test/macros.h>
 #include <test/helpers.h>
 #include <test/random.h>

tests/suites/main_test.function

@@ -29,14 +29,6 @@
 #include MBEDTLS_CONFIG_FILE
 #endif
 
-#if defined(MBEDTLS_USE_PSA_CRYPTO)
-#include "psa/crypto.h"
-#endif /* MBEDTLS_USE_PSA_CRYPTO */
-
-#if defined(MBEDTLS_TEST_HOOKS)
-#include "mbedtls/error.h"
-#endif
-
 /* Test code may use deprecated identifiers only if the preprocessor symbol
  * MBEDTLS_TEST_DEPRECATED is defined. When building tests, set
  * MBEDTLS_TEST_DEPRECATED explicitly if MBEDTLS_DEPRECATED_WARNING is