/** * \file common.h * * \brief Utility macros for internal use in the library */ /* * 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_LIBRARY_COMMON_H #define MBEDTLS_LIBRARY_COMMON_H #include "mbedtls/build_info.h" #include "alignment.h" #include #include #include #include #if defined(__ARM_NEON) #include #endif /* __ARM_NEON */ /** Helper to define a function as static except when building invasive tests. * * If a function is only used inside its own source file and should be * declared `static` to allow the compiler to optimize for code size, * but that function has unit tests, define it with * ``` * MBEDTLS_STATIC_TESTABLE int mbedtls_foo(...) { ... } * ``` * and declare it in a header in the `library/` directory with * ``` * #if defined(MBEDTLS_TEST_HOOKS) * int mbedtls_foo(...); * #endif * ``` */ #if defined(MBEDTLS_TEST_HOOKS) #define MBEDTLS_STATIC_TESTABLE #else #define MBEDTLS_STATIC_TESTABLE static #endif #if defined(MBEDTLS_TEST_HOOKS) extern void (*mbedtls_test_hook_test_fail)(const char *test, int line, const char *file); #define MBEDTLS_TEST_HOOK_TEST_ASSERT(TEST) \ do { \ if ((!(TEST)) && ((*mbedtls_test_hook_test_fail) != NULL)) \ { \ (*mbedtls_test_hook_test_fail)( #TEST, __LINE__, __FILE__); \ } \ } while (0) #else #define MBEDTLS_TEST_HOOK_TEST_ASSERT(TEST) #endif /* defined(MBEDTLS_TEST_HOOKS) */ /** Allow library to access its 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 /** Return an offset into a buffer. * * This is just the addition of an offset to a pointer, except that this * function also accepts an offset of 0 into a buffer whose pointer is null. * (`p + n` has undefined behavior when `p` is null, even when `n == 0`. * A null pointer is a valid buffer pointer when the size is 0, for example * as the result of `malloc(0)` on some platforms.) * * \param p Pointer to a buffer of at least n bytes. * This may be \p NULL if \p n is zero. * \param n An offset in bytes. * \return Pointer to offset \p n in the buffer \p p. * Note that this is only a valid pointer if the size of the * buffer is at least \p n + 1. */ static inline unsigned char *mbedtls_buffer_offset( unsigned char *p, size_t n) { return p == NULL ? NULL : p + n; } /** Return an offset into a read-only buffer. * * Similar to mbedtls_buffer_offset(), but for const pointers. * * \param p Pointer to a buffer of at least n bytes. * This may be \p NULL if \p n is zero. * \param n An offset in bytes. * \return Pointer to offset \p n in the buffer \p p. * Note that this is only a valid pointer if the size of the * buffer is at least \p n + 1. */ static inline const unsigned char *mbedtls_buffer_offset_const( const unsigned char *p, size_t n) { return p == NULL ? NULL : p + n; } /** * Perform a fast block XOR operation, such that * r[i] = a[i] ^ b[i] where 0 <= i < n * * \param r Pointer to result (buffer of at least \p n bytes). \p r * may be equal to either \p a or \p b, but behaviour when * it overlaps in other ways is undefined. * \param a Pointer to input (buffer of at least \p n bytes) * \param b Pointer to input (buffer of at least \p n bytes) * \param n Number of bytes to process. */ inline void mbedtls_xor(unsigned char *r, const unsigned char *a, const unsigned char *b, size_t n) { size_t i = 0; #if defined(MBEDTLS_EFFICIENT_UNALIGNED_ACCESS) #if defined(__ARM_NEON) for (; (i + 16) <= n; i += 16) { uint8x16_t v1 = vld1q_u8(a + i); uint8x16_t v2 = vld1q_u8(b + i); uint8x16_t x = veorq_u8(v1, v2); vst1q_u8(r + i, x); } #elif defined(__amd64__) || defined(__x86_64__) || defined(__aarch64__) /* This codepath probably only makes sense on architectures with 64-bit registers */ for (; (i + 8) <= n; i += 8) { uint64_t x = mbedtls_get_unaligned_uint64(a + i) ^ mbedtls_get_unaligned_uint64(b + i); mbedtls_put_unaligned_uint64(r + i, x); } #else for (; (i + 4) <= n; i += 4) { uint32_t x = mbedtls_get_unaligned_uint32(a + i) ^ mbedtls_get_unaligned_uint32(b + i); mbedtls_put_unaligned_uint32(r + i, x); } #endif #endif for (; i < n; i++) { r[i] = a[i] ^ b[i]; } } /** * Perform a fast block XOR operation, such that * r[i] = a[i] ^ b[i] where 0 <= i < n * * In some situations, this can perform better than mbedtls_xor (e.g., it's about 5% * better in AES-CBC). * * \param r Pointer to result (buffer of at least \p n bytes). \p r * may be equal to either \p a or \p b, but behaviour when * it overlaps in other ways is undefined. * \param a Pointer to input (buffer of at least \p n bytes) * \param b Pointer to input (buffer of at least \p n bytes) * \param n Number of bytes to process. */ static inline void mbedtls_xor_no_simd(unsigned char *r, const unsigned char *a, const unsigned char *b, size_t n) { size_t i = 0; #if defined(MBEDTLS_EFFICIENT_UNALIGNED_ACCESS) #if defined(__amd64__) || defined(__x86_64__) || defined(__aarch64__) /* This codepath probably only makes sense on architectures with 64-bit registers */ for (; (i + 8) <= n; i += 8) { uint64_t x = mbedtls_get_unaligned_uint64(a + i) ^ mbedtls_get_unaligned_uint64(b + i); mbedtls_put_unaligned_uint64(r + i, x); } #else for (; (i + 4) <= n; i += 4) { uint32_t x = mbedtls_get_unaligned_uint32(a + i) ^ mbedtls_get_unaligned_uint32(b + i); mbedtls_put_unaligned_uint32(r + i, x); } #endif #endif for (; i < n; i++) { r[i] = a[i] ^ b[i]; } } /* Fix MSVC C99 compatible issue * MSVC support __func__ from visual studio 2015( 1900 ) * Use MSVC predefine macro to avoid name check fail. */ #if (defined(_MSC_VER) && (_MSC_VER <= 1900)) #define /*no-check-names*/ __func__ __FUNCTION__ #endif /* Define `asm` for compilers which don't define it. */ /* *INDENT-OFF* */ #ifndef asm #define asm __asm__ #endif /* *INDENT-ON* */ /* Always provide a static assert macro, so it can be used unconditionally. * It will expand to nothing on some systems. * Can be used outside functions (but don't add a trailing ';' in that case: * the semicolon is included here to avoid triggering -Wextra-semi when * MBEDTLS_STATIC_ASSERT() expands to nothing). * Can't use the C11-style `defined(static_assert)` on FreeBSD, since it * defines static_assert even with -std=c99, but then complains about it. */ #if defined(static_assert) && !defined(__FreeBSD__) #define MBEDTLS_STATIC_ASSERT(expr, msg) static_assert(expr, msg); #else #define MBEDTLS_STATIC_ASSERT(expr, msg) #endif /* Define compiler branch hints */ #if defined(__has_builtin) #if __has_builtin(__builtin_expect) #define MBEDTLS_LIKELY(x) __builtin_expect((x), 1) #define MBEDTLS_UNLIKELY(x) __builtin_expect((x), 0) #endif #endif #if !defined(MBEDTLS_LIKELY) #define MBEDTLS_LIKELY(x) x #define MBEDTLS_UNLIKELY(x) x #endif #if defined(__GNUC__) && !defined(__ARMCC_VERSION) && !defined(__clang__) \ && !defined(__llvm__) && !defined(__INTEL_COMPILER) /* Defined if the compiler really is gcc and not clang, etc */ #define MBEDTLS_COMPILER_IS_GCC #endif /* For gcc -Os, override with -O2 for a given function. * * This will not affect behaviour for other optimisation settings, e.g. -O0. */ #if defined(MBEDTLS_COMPILER_IS_GCC) && defined(__OPTIMIZE_SIZE__) #define MBEDTLS_OPTIMIZE_FOR_PERFORMANCE __attribute__((optimize("-O2"))) #else #define MBEDTLS_OPTIMIZE_FOR_PERFORMANCE #endif #endif /* MBEDTLS_LIBRARY_COMMON_H */