blob: c5658eb408b0b86821dec8d30f57b1f03f8a4105 [file] [log] [blame]
/**
* \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 OR GPL-2.0-or-later
*/
#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.
*
* \note #TEST_CF_SECRET must be called directly from within a .function file,
* not indirectly via a macro defined under tests/include or a function
* under tests/src. This is because we only run Valgrind for constant
* flow on test suites that have greppable annotations inside them (see
* `skip_suites_without_constant_flow` in `tests/scripts/all.sh`).
*/
#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 */