/** * \file common.h * * \brief Utility macros for internal use in the library */ /* * Copyright The Mbed TLS Contributors * SPDX-License-Identifier: Apache-2.0 OR GPL-2.0-or-later */ #ifndef MBEDTLS_LIBRARY_COMMON_H #define MBEDTLS_LIBRARY_COMMON_H #if defined(MBEDTLS_CONFIG_FILE) #include MBEDTLS_CONFIG_FILE #else #include "mbedtls/config.h" #endif #include #include #include /* Define `inline` on some non-C99-compliant compilers. */ #if (defined(__ARMCC_VERSION) || defined(_MSC_VER)) && \ !defined(inline) && !defined(__cplusplus) #define inline __inline #endif /** 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 /** 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; } /** 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)) /** * 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 base of the first and most significant * byte of the four bytes to build the 32 bits unsigned * integer from. */ #ifndef MBEDTLS_GET_UINT32_BE #define MBEDTLS_GET_UINT32_BE(data, offset) \ ( \ ((uint32_t) (data)[(offset)] << 24) \ | ((uint32_t) (data)[(offset) + 1] << 16) \ | ((uint32_t) (data)[(offset) + 2] << 8) \ | ((uint32_t) (data)[(offset) + 3]) \ ) #endif /** * 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 base where to put the most significant * byte of the 32 bits unsigned integer \p n. */ #ifndef MBEDTLS_PUT_UINT32_BE #define MBEDTLS_PUT_UINT32_BE(n, data, offset) \ { \ (data)[(offset)] = MBEDTLS_BYTE_3(n); \ (data)[(offset) + 1] = MBEDTLS_BYTE_2(n); \ (data)[(offset) + 2] = MBEDTLS_BYTE_1(n); \ (data)[(offset) + 3] = MBEDTLS_BYTE_0(n); \ } #endif /** * 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 base of the first and least significant * byte of the four bytes to build the 32 bits unsigned * integer from. */ #ifndef MBEDTLS_GET_UINT32_LE #define MBEDTLS_GET_UINT32_LE(data, offset) \ ( \ ((uint32_t) (data)[(offset)]) \ | ((uint32_t) (data)[(offset) + 1] << 8) \ | ((uint32_t) (data)[(offset) + 2] << 16) \ | ((uint32_t) (data)[(offset) + 3] << 24) \ ) #endif /** * 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 base where to put the least significant * byte of the 32 bits unsigned integer \p n. */ #ifndef MBEDTLS_PUT_UINT32_LE #define MBEDTLS_PUT_UINT32_LE(n, data, offset) \ { \ (data)[(offset)] = MBEDTLS_BYTE_0(n); \ (data)[(offset) + 1] = MBEDTLS_BYTE_1(n); \ (data)[(offset) + 2] = MBEDTLS_BYTE_2(n); \ (data)[(offset) + 3] = MBEDTLS_BYTE_3(n); \ } #endif /** * 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 base of the first and least significant * byte of the two bytes to build the 16 bits unsigned * integer from. */ #ifndef MBEDTLS_GET_UINT16_LE #define MBEDTLS_GET_UINT16_LE(data, offset) \ ( \ ((uint16_t) (data)[(offset)]) \ | ((uint16_t) (data)[(offset) + 1] << 8) \ ) #endif /** * 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 base where to put the least significant * byte of the 16 bits unsigned integer \p n. */ #ifndef MBEDTLS_PUT_UINT16_LE #define MBEDTLS_PUT_UINT16_LE(n, data, offset) \ { \ (data)[(offset)] = MBEDTLS_BYTE_0(n); \ (data)[(offset) + 1] = MBEDTLS_BYTE_1(n); \ } #endif /** * 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 base of the first and most significant * byte of the two bytes to build the 16 bits unsigned * integer from. */ #ifndef MBEDTLS_GET_UINT16_BE #define MBEDTLS_GET_UINT16_BE(data, offset) \ ( \ ((uint16_t) (data)[(offset)] << 8) \ | ((uint16_t) (data)[(offset) + 1]) \ ) #endif /** * 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 base where to put the most significant * byte of the 16 bits unsigned integer \p n. */ #ifndef MBEDTLS_PUT_UINT16_BE #define MBEDTLS_PUT_UINT16_BE(n, data, offset) \ { \ (data)[(offset)] = MBEDTLS_BYTE_1(n); \ (data)[(offset) + 1] = MBEDTLS_BYTE_0(n); \ } #endif /** * 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 base of the first and most significant * byte of the eight bytes to build the 64 bits unsigned * integer from. */ #ifndef MBEDTLS_GET_UINT64_BE #define MBEDTLS_GET_UINT64_BE(data, offset) \ ( \ ((uint64_t) (data)[(offset)] << 56) \ | ((uint64_t) (data)[(offset) + 1] << 48) \ | ((uint64_t) (data)[(offset) + 2] << 40) \ | ((uint64_t) (data)[(offset) + 3] << 32) \ | ((uint64_t) (data)[(offset) + 4] << 24) \ | ((uint64_t) (data)[(offset) + 5] << 16) \ | ((uint64_t) (data)[(offset) + 6] << 8) \ | ((uint64_t) (data)[(offset) + 7]) \ ) #endif /** * 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 base where to put the most significant * byte of the 64 bits unsigned integer \p n. */ #ifndef MBEDTLS_PUT_UINT64_BE #define MBEDTLS_PUT_UINT64_BE(n, data, offset) \ { \ (data)[(offset)] = MBEDTLS_BYTE_7(n); \ (data)[(offset) + 1] = MBEDTLS_BYTE_6(n); \ (data)[(offset) + 2] = MBEDTLS_BYTE_5(n); \ (data)[(offset) + 3] = MBEDTLS_BYTE_4(n); \ (data)[(offset) + 4] = MBEDTLS_BYTE_3(n); \ (data)[(offset) + 5] = MBEDTLS_BYTE_2(n); \ (data)[(offset) + 6] = MBEDTLS_BYTE_1(n); \ (data)[(offset) + 7] = MBEDTLS_BYTE_0(n); \ } #endif /** * 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 base of the first and least significant * byte of the eight bytes to build the 64 bits unsigned * integer from. */ #ifndef MBEDTLS_GET_UINT64_LE #define MBEDTLS_GET_UINT64_LE(data, offset) \ ( \ ((uint64_t) (data)[(offset) + 7] << 56) \ | ((uint64_t) (data)[(offset) + 6] << 48) \ | ((uint64_t) (data)[(offset) + 5] << 40) \ | ((uint64_t) (data)[(offset) + 4] << 32) \ | ((uint64_t) (data)[(offset) + 3] << 24) \ | ((uint64_t) (data)[(offset) + 2] << 16) \ | ((uint64_t) (data)[(offset) + 1] << 8) \ | ((uint64_t) (data)[(offset)]) \ ) #endif /** * 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 base where to put the least significant * byte of the 64 bits unsigned integer \p n. */ #ifndef MBEDTLS_PUT_UINT64_LE #define MBEDTLS_PUT_UINT64_LE(n, data, offset) \ { \ (data)[(offset)] = MBEDTLS_BYTE_0(n); \ (data)[(offset) + 1] = MBEDTLS_BYTE_1(n); \ (data)[(offset) + 2] = MBEDTLS_BYTE_2(n); \ (data)[(offset) + 3] = MBEDTLS_BYTE_3(n); \ (data)[(offset) + 4] = MBEDTLS_BYTE_4(n); \ (data)[(offset) + 5] = MBEDTLS_BYTE_5(n); \ (data)[(offset) + 6] = MBEDTLS_BYTE_6(n); \ (data)[(offset) + 7] = MBEDTLS_BYTE_7(n); \ } #endif /* Always provide a static assert macro, so it can be used unconditionally. * It will expand to nothing on some systems. */ /* 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 /* Make sure `MBEDTLS_STATIC_ASSERT(expr, msg);` is valid both inside and * outside a function. We choose a struct declaration, which can be repeated * any number of times and does not need a matching definition. */ #define MBEDTLS_STATIC_ASSERT(expr, msg) \ struct ISO_C_does_not_allow_extra_semicolon_outside_of_a_function #endif /* Suppress compiler warnings for unused functions and variables. */ #if !defined(MBEDTLS_MAYBE_UNUSED) && defined(__has_attribute) # if __has_attribute(unused) # define MBEDTLS_MAYBE_UNUSED __attribute__((unused)) # endif #endif #if !defined(MBEDTLS_MAYBE_UNUSED) && defined(__GNUC__) # define MBEDTLS_MAYBE_UNUSED __attribute__((unused)) #endif #if !defined(MBEDTLS_MAYBE_UNUSED) && defined(__IAR_SYSTEMS_ICC__) && defined(__VER__) /* IAR does support __attribute__((unused)), but only if the -e flag (extended language support) * is given; the pragma always works. * Unfortunately the pragma affects the rest of the file where it is used, but this is harmless. * Check for version 5.2 or later - this pragma may be supported by earlier versions, but I wasn't * able to find documentation). */ # if (__VER__ >= 5020000) # define MBEDTLS_MAYBE_UNUSED _Pragma("diag_suppress=Pe177") # endif #endif #if !defined(MBEDTLS_MAYBE_UNUSED) && defined(_MSC_VER) # define MBEDTLS_MAYBE_UNUSED __pragma(warning(suppress:4189)) #endif #if !defined(MBEDTLS_MAYBE_UNUSED) # define MBEDTLS_MAYBE_UNUSED #endif #endif /* MBEDTLS_LIBRARY_COMMON_H */