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/**
* \file constant_flow.h
*
* \brief This file contains tools to ensure tested code has constant flow.
*/
/*
* 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 TEST_CONSTANT_FLOW_H
#define TEST_CONSTANT_FLOW_H
#include "mbedtls/build_info.h"
/*
* This file defines the two macros
*
* #define TEST_CF_SECRET(ptr, size)
* #define TEST_CF_PUBLIC(ptr, size)
*
* that can be used in tests to mark a memory area as secret (no branch or
* memory access should depend on it) or public (default, only needs to be
* marked explicitly when it was derived from secret data).
*
* Arguments:
* - ptr: a pointer to the memory area to be marked
* - size: the size in bytes of the memory area
*
* Implementation:
* The basic idea is that of ctgrind <https://github.com/agl/ctgrind>: we can
* re-use tools that were designed for checking use of uninitialized memory.
* This file contains two implementations: one based on MemorySanitizer, the
* other on valgrind's memcheck. If none of them is enabled, dummy macros that
* do nothing are defined for convenience.
*/
#if defined(MBEDTLS_TEST_CONSTANT_FLOW_MEMSAN)
#include <sanitizer/msan_interface.h>
/* Use macros to avoid messing up with origin tracking */
#define TEST_CF_SECRET __msan_allocated_memory
// void __msan_allocated_memory(const volatile void* data, size_t size);
#define TEST_CF_PUBLIC __msan_unpoison
// void __msan_unpoison(const volatile void *a, size_t size);
#elif defined(MBEDTLS_TEST_CONSTANT_FLOW_VALGRIND)
#include <valgrind/memcheck.h>
#define TEST_CF_SECRET VALGRIND_MAKE_MEM_UNDEFINED
// VALGRIND_MAKE_MEM_UNDEFINED(_qzz_addr, _qzz_len)
#define TEST_CF_PUBLIC VALGRIND_MAKE_MEM_DEFINED
// VALGRIND_MAKE_MEM_DEFINED(_qzz_addr, _qzz_len)
#else /* MBEDTLS_TEST_CONSTANT_FLOW_MEMSAN ||
MBEDTLS_TEST_CONSTANT_FLOW_VALGRIND */
#define TEST_CF_SECRET(ptr, size)
#define TEST_CF_PUBLIC(ptr, size)
#endif /* MBEDTLS_TEST_CONSTANT_FLOW_MEMSAN ||
MBEDTLS_TEST_CONSTANT_FLOW_VALGRIND */
#endif /* TEST_CONSTANT_FLOW_H */