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 10 * 11 * Licensed under the Apache License, Version 2.0 (the "License"); you may 12 * not use this file except in compliance with the License. 13 * You may obtain a copy of the License at 14 * 15 * http://www.apache.org/licenses/LICENSE-2.0 16 * 17 * Unless required by applicable law or agreed to in writing, software 18 * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT 19 * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 20 * See the License for the specific language governing permissions and 21 * limitations under the License. 22 */ 23 24 #ifndef TEST_CONSTANT_FLOW_H 25 #define TEST_CONSTANT_FLOW_H 26 27 #if !defined(MBEDTLS_CONFIG_FILE) 28 #include "mbedtls/config.h" 29 #else 30 #include MBEDTLS_CONFIG_FILE 31 #endif 32 33 /* 34 * This file defines the two macros 35 * 36 * #define TEST_CF_SECRET(ptr, size) 37 * #define TEST_CF_PUBLIC(ptr, size) 38 * 39 * that can be used in tests to mark a memory area as secret (no branch or 40 * memory access should depend on it) or public (default, only needs to be 41 * marked explicitly when it was derived from secret data). 42 * 43 * Arguments: 44 * - ptr: a pointer to the memory area to be marked 45 * - size: the size in bytes of the memory area 46 * 47 * Implementation: 48 * The basic idea is that of ctgrind <https://github.com/agl/ctgrind>: we can 49 * re-use tools that were designed for checking use of uninitialized memory. 50 * This file contains two implementations: one based on MemorySanitizer, the 51 * other on valgrind's memcheck. If none of them is enabled, dummy macros that 52 * do nothing are defined for convenience. 53 */ 54 55 #if defined(MBEDTLS_TEST_CONSTANT_FLOW_MEMSAN) 56 #include <sanitizer/msan_interface.h> 57 58 /* Use macros to avoid messing up with origin tracking */ 59 #define TEST_CF_SECRET __msan_allocated_memory 60 // void __msan_allocated_memory(const volatile void* data, size_t size); 61 #define TEST_CF_PUBLIC __msan_unpoison 62 // void __msan_unpoison(const volatile void *a, size_t size); 63 64 #elif defined(MBEDTLS_TEST_CONSTANT_FLOW_VALGRIND) 65 #include <valgrind/memcheck.h> 66 67 #define TEST_CF_SECRET VALGRIND_MAKE_MEM_UNDEFINED 68 // VALGRIND_MAKE_MEM_UNDEFINED(_qzz_addr, _qzz_len) 69 #define TEST_CF_PUBLIC VALGRIND_MAKE_MEM_DEFINED 70 // VALGRIND_MAKE_MEM_DEFINED(_qzz_addr, _qzz_len) 71 72 #else /* MBEDTLS_TEST_CONSTANT_FLOW_MEMSAN || 73 MBEDTLS_TEST_CONSTANT_FLOW_VALGRIND */ 74 75 #define TEST_CF_SECRET(ptr, size) 76 #define TEST_CF_PUBLIC(ptr, size) 77 78 #endif /* MBEDTLS_TEST_CONSTANT_FLOW_MEMSAN || 79 MBEDTLS_TEST_CONSTANT_FLOW_VALGRIND */ 80 81 #endif /* TEST_CONSTANT_FLOW_H */ 82