/**
* \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 <assert.h>
#include <stddef.h>
#include <stdint.h>
/* 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 */