constant_flow.h (2482B)
1 /** 2 * \file constant_flow.h 3 * 4 * \brief This file contains tools to ensure tested code has constant flow. 5 */ 6 7 /* 8 * Copyright The Mbed TLS Contributors 9 * SPDX-License-Identifier: Apache-2.0 OR GPL-2.0-or-later 10 */ 11 12 #ifndef TEST_CONSTANT_FLOW_H 13 #define TEST_CONSTANT_FLOW_H 14 15 #include "mbedtls/build_info.h" 16 17 /* 18 * This file defines the two macros 19 * 20 * #define TEST_CF_SECRET(ptr, size) 21 * #define TEST_CF_PUBLIC(ptr, size) 22 * 23 * that can be used in tests to mark a memory area as secret (no branch or 24 * memory access should depend on it) or public (default, only needs to be 25 * marked explicitly when it was derived from secret data). 26 * 27 * Arguments: 28 * - ptr: a pointer to the memory area to be marked 29 * - size: the size in bytes of the memory area 30 * 31 * Implementation: 32 * The basic idea is that of ctgrind <https://github.com/agl/ctgrind>: we can 33 * re-use tools that were designed for checking use of uninitialized memory. 34 * This file contains two implementations: one based on MemorySanitizer, the 35 * other on valgrind's memcheck. If none of them is enabled, dummy macros that 36 * do nothing are defined for convenience. 37 * 38 * \note #TEST_CF_SECRET must be called directly from within a .function file, 39 * not indirectly via a macro defined under tests/include or a function 40 * under tests/src. This is because we only run Valgrind for constant 41 * flow on test suites that have greppable annotations inside them (see 42 * `skip_suites_without_constant_flow` in `tests/scripts/all.sh`). 43 */ 44 45 #if defined(MBEDTLS_TEST_CONSTANT_FLOW_MEMSAN) 46 #include <sanitizer/msan_interface.h> 47 48 /* Use macros to avoid messing up with origin tracking */ 49 #define TEST_CF_SECRET __msan_allocated_memory 50 // void __msan_allocated_memory(const volatile void* data, size_t size); 51 #define TEST_CF_PUBLIC __msan_unpoison 52 // void __msan_unpoison(const volatile void *a, size_t size); 53 54 #elif defined(MBEDTLS_TEST_CONSTANT_FLOW_VALGRIND) 55 #include <valgrind/memcheck.h> 56 57 #define TEST_CF_SECRET VALGRIND_MAKE_MEM_UNDEFINED 58 // VALGRIND_MAKE_MEM_UNDEFINED(_qzz_addr, _qzz_len) 59 #define TEST_CF_PUBLIC VALGRIND_MAKE_MEM_DEFINED 60 // VALGRIND_MAKE_MEM_DEFINED(_qzz_addr, _qzz_len) 61 62 #else /* MBEDTLS_TEST_CONSTANT_FLOW_MEMSAN || 63 MBEDTLS_TEST_CONSTANT_FLOW_VALGRIND */ 64 65 #define TEST_CF_SECRET(ptr, size) 66 #define TEST_CF_PUBLIC(ptr, size) 67 68 #endif /* MBEDTLS_TEST_CONSTANT_FLOW_MEMSAN || 69 MBEDTLS_TEST_CONSTANT_FLOW_VALGRIND */ 70 71 #endif /* TEST_CONSTANT_FLOW_H */