/** * \file alignment.h * * \brief Utility code for dealing with unaligned memory accesses */ /* * Copyright The Mbed TLS Contributors * SPDX-License-Identifier: Apache-2.0 OR GPL-2.0-or-later */ #ifndef MBEDTLS_LIBRARY_ALIGNMENT_H #define MBEDTLS_LIBRARY_ALIGNMENT_H #include #include #include /* * Define MBEDTLS_EFFICIENT_UNALIGNED_ACCESS for architectures where unaligned memory * accesses are known to be efficient. * * All functions defined here will behave correctly regardless, but might be less * efficient when this is not defined. */ #if defined(__ARM_FEATURE_UNALIGNED) \ || defined(MBEDTLS_ARCH_IS_X86) || defined(MBEDTLS_ARCH_IS_X64) \ || defined(MBEDTLS_PLATFORM_IS_WINDOWS_ON_ARM64) /* * __ARM_FEATURE_UNALIGNED is defined where appropriate by armcc, gcc 7, clang 9 * (and later versions) for Arm v7 and later; all x86 platforms should have * efficient unaligned access. * * https://learn.microsoft.com/en-us/cpp/build/arm64-windows-abi-conventions?view=msvc-170#alignment * specifies that on Windows-on-Arm64, unaligned access is safe (except for uncached * device memory). */ #define MBEDTLS_EFFICIENT_UNALIGNED_ACCESS #endif /** * Read the unsigned 16 bits integer from the given address, which need not * be aligned. * * \param p pointer to 2 bytes of data * \return Data at the given address */ inline uint16_t mbedtls_get_unaligned_uint16(const void *p) { uint16_t r; memcpy(&r, p, sizeof(r)); return r; } /** * Write the unsigned 16 bits integer to the given address, which need not * be aligned. * * \param p pointer to 2 bytes of data * \param x data to write */ inline void mbedtls_put_unaligned_uint16(void *p, uint16_t x) { memcpy(p, &x, sizeof(x)); } /** * Read the unsigned 32 bits integer from the given address, which need not * be aligned. * * \param p pointer to 4 bytes of data * \return Data at the given address */ inline uint32_t mbedtls_get_unaligned_uint32(const void *p) { uint32_t r; memcpy(&r, p, sizeof(r)); return r; } /** * Write the unsigned 32 bits integer to the given address, which need not * be aligned. * * \param p pointer to 4 bytes of data * \param x data to write */ inline void mbedtls_put_unaligned_uint32(void *p, uint32_t x) { memcpy(p, &x, sizeof(x)); } /** * Read the unsigned 64 bits integer from the given address, which need not * be aligned. * * \param p pointer to 8 bytes of data * \return Data at the given address */ inline uint64_t mbedtls_get_unaligned_uint64(const void *p) { uint64_t r; memcpy(&r, p, sizeof(r)); return r; } /** * Write the unsigned 64 bits integer to the given address, which need not * be aligned. * * \param p pointer to 8 bytes of data * \param x data to write */ inline void mbedtls_put_unaligned_uint64(void *p, uint64_t x) { memcpy(p, &x, sizeof(x)); } /** Byte Reading Macros * * Given a multi-byte integer \p x, MBEDTLS_BYTE_n retrieves the n-th * byte from x, where byte 0 is the least significant byte. */ #define MBEDTLS_BYTE_0(x) ((uint8_t) ((x) & 0xff)) #define MBEDTLS_BYTE_1(x) ((uint8_t) (((x) >> 8) & 0xff)) #define MBEDTLS_BYTE_2(x) ((uint8_t) (((x) >> 16) & 0xff)) #define MBEDTLS_BYTE_3(x) ((uint8_t) (((x) >> 24) & 0xff)) #define MBEDTLS_BYTE_4(x) ((uint8_t) (((x) >> 32) & 0xff)) #define MBEDTLS_BYTE_5(x) ((uint8_t) (((x) >> 40) & 0xff)) #define MBEDTLS_BYTE_6(x) ((uint8_t) (((x) >> 48) & 0xff)) #define MBEDTLS_BYTE_7(x) ((uint8_t) (((x) >> 56) & 0xff)) /* * Detect GCC built-in byteswap routines */ #if defined(__GNUC__) && defined(__GNUC_PREREQ) #if __GNUC_PREREQ(4, 8) #define MBEDTLS_BSWAP16 __builtin_bswap16 #endif /* __GNUC_PREREQ(4,8) */ #if __GNUC_PREREQ(4, 3) #define MBEDTLS_BSWAP32 __builtin_bswap32 #define MBEDTLS_BSWAP64 __builtin_bswap64 #endif /* __GNUC_PREREQ(4,3) */ #endif /* defined(__GNUC__) && defined(__GNUC_PREREQ) */ /* * Detect Clang built-in byteswap routines */ #if defined(__clang__) && defined(__has_builtin) #if __has_builtin(__builtin_bswap16) && !defined(MBEDTLS_BSWAP16) #define MBEDTLS_BSWAP16 __builtin_bswap16 #endif /* __has_builtin(__builtin_bswap16) */ #if __has_builtin(__builtin_bswap32) && !defined(MBEDTLS_BSWAP32) #define MBEDTLS_BSWAP32 __builtin_bswap32 #endif /* __has_builtin(__builtin_bswap32) */ #if __has_builtin(__builtin_bswap64) && !defined(MBEDTLS_BSWAP64) #define MBEDTLS_BSWAP64 __builtin_bswap64 #endif /* __has_builtin(__builtin_bswap64) */ #endif /* defined(__clang__) && defined(__has_builtin) */ /* * Detect MSVC built-in byteswap routines */ #if defined(_MSC_VER) #if !defined(MBEDTLS_BSWAP16) #define MBEDTLS_BSWAP16 _byteswap_ushort #endif #if !defined(MBEDTLS_BSWAP32) #define MBEDTLS_BSWAP32 _byteswap_ulong #endif #if !defined(MBEDTLS_BSWAP64) #define MBEDTLS_BSWAP64 _byteswap_uint64 #endif #endif /* defined(_MSC_VER) */ /* Detect armcc built-in byteswap routine */ #if defined(__ARMCC_VERSION) && (__ARMCC_VERSION >= 410000) && !defined(MBEDTLS_BSWAP32) #if defined(__ARM_ACLE) /* ARM Compiler 6 - earlier versions don't need a header */ #include #endif #define MBEDTLS_BSWAP32 __rev #endif /* Detect IAR built-in byteswap routine */ #if defined(__IAR_SYSTEMS_ICC__) #if defined(__ARM_ACLE) #include #define MBEDTLS_BSWAP16(x) ((uint16_t) __rev16((uint32_t) (x))) #define MBEDTLS_BSWAP32 __rev #define MBEDTLS_BSWAP64 __revll #endif #endif /* * Where compiler built-ins are not present, fall back to C code that the * compiler may be able to detect and transform into the relevant bswap or * similar instruction. */ #if !defined(MBEDTLS_BSWAP16) static inline uint16_t mbedtls_bswap16(uint16_t x) { return (x & 0x00ff) << 8 | (x & 0xff00) >> 8; } #define MBEDTLS_BSWAP16 mbedtls_bswap16 #endif /* !defined(MBEDTLS_BSWAP16) */ #if !defined(MBEDTLS_BSWAP32) static inline uint32_t mbedtls_bswap32(uint32_t x) { return (x & 0x000000ff) << 24 | (x & 0x0000ff00) << 8 | (x & 0x00ff0000) >> 8 | (x & 0xff000000) >> 24; } #define MBEDTLS_BSWAP32 mbedtls_bswap32 #endif /* !defined(MBEDTLS_BSWAP32) */ #if !defined(MBEDTLS_BSWAP64) static inline uint64_t mbedtls_bswap64(uint64_t x) { return (x & 0x00000000000000ffULL) << 56 | (x & 0x000000000000ff00ULL) << 40 | (x & 0x0000000000ff0000ULL) << 24 | (x & 0x00000000ff000000ULL) << 8 | (x & 0x000000ff00000000ULL) >> 8 | (x & 0x0000ff0000000000ULL) >> 24 | (x & 0x00ff000000000000ULL) >> 40 | (x & 0xff00000000000000ULL) >> 56; } #define MBEDTLS_BSWAP64 mbedtls_bswap64 #endif /* !defined(MBEDTLS_BSWAP64) */ #if !defined(__BYTE_ORDER__) #if defined(__LITTLE_ENDIAN__) /* IAR defines __xxx_ENDIAN__, but not __BYTE_ORDER__ */ #define MBEDTLS_IS_BIG_ENDIAN 0 #elif defined(__BIG_ENDIAN__) #define MBEDTLS_IS_BIG_ENDIAN 1 #else static const uint16_t mbedtls_byte_order_detector = { 0x100 }; #define MBEDTLS_IS_BIG_ENDIAN (*((unsigned char *) (&mbedtls_byte_order_detector)) == 0x01) #endif #else #if (__BYTE_ORDER__) == (__ORDER_BIG_ENDIAN__) #define MBEDTLS_IS_BIG_ENDIAN 1 #else #define MBEDTLS_IS_BIG_ENDIAN 0 #endif #endif /* !defined(__BYTE_ORDER__) */ /** * Get the unsigned 32 bits integer corresponding to four bytes in * big-endian order (MSB first). * * \param data Base address of the memory to get the four bytes from. * \param offset Offset from \p data of the first and most significant * byte of the four bytes to build the 32 bits unsigned * integer from. */ #define MBEDTLS_GET_UINT32_BE(data, offset) \ ((MBEDTLS_IS_BIG_ENDIAN) \ ? mbedtls_get_unaligned_uint32((data) + (offset)) \ : MBEDTLS_BSWAP32(mbedtls_get_unaligned_uint32((data) + (offset))) \ ) /** * Put in memory a 32 bits unsigned integer in big-endian order. * * \param n 32 bits unsigned integer to put in memory. * \param data Base address of the memory where to put the 32 * bits unsigned integer in. * \param offset Offset from \p data where to put the most significant * byte of the 32 bits unsigned integer \p n. */ #define MBEDTLS_PUT_UINT32_BE(n, data, offset) \ { \ if (MBEDTLS_IS_BIG_ENDIAN) \ { \ mbedtls_put_unaligned_uint32((data) + (offset), (uint32_t) (n)); \ } \ else \ { \ mbedtls_put_unaligned_uint32((data) + (offset), MBEDTLS_BSWAP32((uint32_t) (n))); \ } \ } /** * Get the unsigned 32 bits integer corresponding to four bytes in * little-endian order (LSB first). * * \param data Base address of the memory to get the four bytes from. * \param offset Offset from \p data of the first and least significant * byte of the four bytes to build the 32 bits unsigned * integer from. */ #define MBEDTLS_GET_UINT32_LE(data, offset) \ ((MBEDTLS_IS_BIG_ENDIAN) \ ? MBEDTLS_BSWAP32(mbedtls_get_unaligned_uint32((data) + (offset))) \ : mbedtls_get_unaligned_uint32((data) + (offset)) \ ) /** * Put in memory a 32 bits unsigned integer in little-endian order. * * \param n 32 bits unsigned integer to put in memory. * \param data Base address of the memory where to put the 32 * bits unsigned integer in. * \param offset Offset from \p data where to put the least significant * byte of the 32 bits unsigned integer \p n. */ #define MBEDTLS_PUT_UINT32_LE(n, data, offset) \ { \ if (MBEDTLS_IS_BIG_ENDIAN) \ { \ mbedtls_put_unaligned_uint32((data) + (offset), MBEDTLS_BSWAP32((uint32_t) (n))); \ } \ else \ { \ mbedtls_put_unaligned_uint32((data) + (offset), ((uint32_t) (n))); \ } \ } /** * Get the unsigned 16 bits integer corresponding to two bytes in * little-endian order (LSB first). * * \param data Base address of the memory to get the two bytes from. * \param offset Offset from \p data of the first and least significant * byte of the two bytes to build the 16 bits unsigned * integer from. */ #define MBEDTLS_GET_UINT16_LE(data, offset) \ ((MBEDTLS_IS_BIG_ENDIAN) \ ? MBEDTLS_BSWAP16(mbedtls_get_unaligned_uint16((data) + (offset))) \ : mbedtls_get_unaligned_uint16((data) + (offset)) \ ) /** * Put in memory a 16 bits unsigned integer in little-endian order. * * \param n 16 bits unsigned integer to put in memory. * \param data Base address of the memory where to put the 16 * bits unsigned integer in. * \param offset Offset from \p data where to put the least significant * byte of the 16 bits unsigned integer \p n. */ #define MBEDTLS_PUT_UINT16_LE(n, data, offset) \ { \ if (MBEDTLS_IS_BIG_ENDIAN) \ { \ mbedtls_put_unaligned_uint16((data) + (offset), MBEDTLS_BSWAP16((uint16_t) (n))); \ } \ else \ { \ mbedtls_put_unaligned_uint16((data) + (offset), (uint16_t) (n)); \ } \ } /** * Get the unsigned 16 bits integer corresponding to two bytes in * big-endian order (MSB first). * * \param data Base address of the memory to get the two bytes from. * \param offset Offset from \p data of the first and most significant * byte of the two bytes to build the 16 bits unsigned * integer from. */ #define MBEDTLS_GET_UINT16_BE(data, offset) \ ((MBEDTLS_IS_BIG_ENDIAN) \ ? mbedtls_get_unaligned_uint16((data) + (offset)) \ : MBEDTLS_BSWAP16(mbedtls_get_unaligned_uint16((data) + (offset))) \ ) /** * Put in memory a 16 bits unsigned integer in big-endian order. * * \param n 16 bits unsigned integer to put in memory. * \param data Base address of the memory where to put the 16 * bits unsigned integer in. * \param offset Offset from \p data where to put the most significant * byte of the 16 bits unsigned integer \p n. */ #define MBEDTLS_PUT_UINT16_BE(n, data, offset) \ { \ if (MBEDTLS_IS_BIG_ENDIAN) \ { \ mbedtls_put_unaligned_uint16((data) + (offset), (uint16_t) (n)); \ } \ else \ { \ mbedtls_put_unaligned_uint16((data) + (offset), MBEDTLS_BSWAP16((uint16_t) (n))); \ } \ } /** * Get the unsigned 24 bits integer corresponding to three bytes in * big-endian order (MSB first). * * \param data Base address of the memory to get the three bytes from. * \param offset Offset from \p data of the first and most significant * byte of the three bytes to build the 24 bits unsigned * integer from. */ #define MBEDTLS_GET_UINT24_BE(data, offset) \ ( \ ((uint32_t) (data)[(offset)] << 16) \ | ((uint32_t) (data)[(offset) + 1] << 8) \ | ((uint32_t) (data)[(offset) + 2]) \ ) /** * Put in memory a 24 bits unsigned integer in big-endian order. * * \param n 24 bits unsigned integer to put in memory. * \param data Base address of the memory where to put the 24 * bits unsigned integer in. * \param offset Offset from \p data where to put the most significant * byte of the 24 bits unsigned integer \p n. */ #define MBEDTLS_PUT_UINT24_BE(n, data, offset) \ { \ (data)[(offset)] = MBEDTLS_BYTE_2(n); \ (data)[(offset) + 1] = MBEDTLS_BYTE_1(n); \ (data)[(offset) + 2] = MBEDTLS_BYTE_0(n); \ } /** * Get the unsigned 24 bits integer corresponding to three bytes in * little-endian order (LSB first). * * \param data Base address of the memory to get the three bytes from. * \param offset Offset from \p data of the first and least significant * byte of the three bytes to build the 24 bits unsigned * integer from. */ #define MBEDTLS_GET_UINT24_LE(data, offset) \ ( \ ((uint32_t) (data)[(offset)]) \ | ((uint32_t) (data)[(offset) + 1] << 8) \ | ((uint32_t) (data)[(offset) + 2] << 16) \ ) /** * Put in memory a 24 bits unsigned integer in little-endian order. * * \param n 24 bits unsigned integer to put in memory. * \param data Base address of the memory where to put the 24 * bits unsigned integer in. * \param offset Offset from \p data where to put the least significant * byte of the 24 bits unsigned integer \p n. */ #define MBEDTLS_PUT_UINT24_LE(n, data, offset) \ { \ (data)[(offset)] = MBEDTLS_BYTE_0(n); \ (data)[(offset) + 1] = MBEDTLS_BYTE_1(n); \ (data)[(offset) + 2] = MBEDTLS_BYTE_2(n); \ } /** * Get the unsigned 64 bits integer corresponding to eight bytes in * big-endian order (MSB first). * * \param data Base address of the memory to get the eight bytes from. * \param offset Offset from \p data of the first and most significant * byte of the eight bytes to build the 64 bits unsigned * integer from. */ #define MBEDTLS_GET_UINT64_BE(data, offset) \ ((MBEDTLS_IS_BIG_ENDIAN) \ ? mbedtls_get_unaligned_uint64((data) + (offset)) \ : MBEDTLS_BSWAP64(mbedtls_get_unaligned_uint64((data) + (offset))) \ ) /** * Put in memory a 64 bits unsigned integer in big-endian order. * * \param n 64 bits unsigned integer to put in memory. * \param data Base address of the memory where to put the 64 * bits unsigned integer in. * \param offset Offset from \p data where to put the most significant * byte of the 64 bits unsigned integer \p n. */ #define MBEDTLS_PUT_UINT64_BE(n, data, offset) \ { \ if (MBEDTLS_IS_BIG_ENDIAN) \ { \ mbedtls_put_unaligned_uint64((data) + (offset), (uint64_t) (n)); \ } \ else \ { \ mbedtls_put_unaligned_uint64((data) + (offset), MBEDTLS_BSWAP64((uint64_t) (n))); \ } \ } /** * Get the unsigned 64 bits integer corresponding to eight bytes in * little-endian order (LSB first). * * \param data Base address of the memory to get the eight bytes from. * \param offset Offset from \p data of the first and least significant * byte of the eight bytes to build the 64 bits unsigned * integer from. */ #define MBEDTLS_GET_UINT64_LE(data, offset) \ ((MBEDTLS_IS_BIG_ENDIAN) \ ? MBEDTLS_BSWAP64(mbedtls_get_unaligned_uint64((data) + (offset))) \ : mbedtls_get_unaligned_uint64((data) + (offset)) \ ) /** * Put in memory a 64 bits unsigned integer in little-endian order. * * \param n 64 bits unsigned integer to put in memory. * \param data Base address of the memory where to put the 64 * bits unsigned integer in. * \param offset Offset from \p data where to put the least significant * byte of the 64 bits unsigned integer \p n. */ #define MBEDTLS_PUT_UINT64_LE(n, data, offset) \ { \ if (MBEDTLS_IS_BIG_ENDIAN) \ { \ mbedtls_put_unaligned_uint64((data) + (offset), MBEDTLS_BSWAP64((uint64_t) (n))); \ } \ else \ { \ mbedtls_put_unaligned_uint64((data) + (offset), (uint64_t) (n)); \ } \ } #endif /* MBEDTLS_LIBRARY_ALIGNMENT_H */