326 lines
11 KiB
C
326 lines
11 KiB
C
/***********************************************************************
|
|
* Copyright (c) 2013, 2014 Pieter Wuille *
|
|
* Distributed under the MIT software license, see the accompanying *
|
|
* file COPYING or https://www.opensource.org/licenses/mit-license.php.*
|
|
***********************************************************************/
|
|
|
|
#ifndef SECP256K1_UTIL_H
|
|
#define SECP256K1_UTIL_H
|
|
|
|
#if defined HAVE_CONFIG_H
|
|
#include "libsecp256k1-config.h"
|
|
#endif
|
|
|
|
#include <stdlib.h>
|
|
#include <stdint.h>
|
|
#include <stdio.h>
|
|
#include <limits.h>
|
|
|
|
typedef struct {
|
|
void (*fn)(const char *text, void* data);
|
|
const void* data;
|
|
} rustsecp256k1_v0_5_0_callback;
|
|
|
|
static SECP256K1_INLINE void rustsecp256k1_v0_5_0_callback_call(const rustsecp256k1_v0_5_0_callback * const cb, const char * const text) {
|
|
cb->fn(text, (void*)cb->data);
|
|
}
|
|
|
|
#ifndef USE_EXTERNAL_DEFAULT_CALLBACKS
|
|
static void rustsecp256k1_v0_5_0_default_illegal_callback_fn(const char* str, void* data) {
|
|
(void)data;
|
|
fprintf(stderr, "[libsecp256k1] illegal argument: %s\n", str);
|
|
abort();
|
|
}
|
|
static void rustsecp256k1_v0_5_0_default_error_callback_fn(const char* str, void* data) {
|
|
(void)data;
|
|
fprintf(stderr, "[libsecp256k1] internal consistency check failed: %s\n", str);
|
|
abort();
|
|
}
|
|
#else
|
|
void rustsecp256k1_v0_5_0_default_illegal_callback_fn(const char* str, void* data);
|
|
void rustsecp256k1_v0_5_0_default_error_callback_fn(const char* str, void* data);
|
|
#endif
|
|
|
|
static const rustsecp256k1_v0_5_0_callback default_illegal_callback = {
|
|
rustsecp256k1_v0_5_0_default_illegal_callback_fn,
|
|
NULL
|
|
};
|
|
|
|
static const rustsecp256k1_v0_5_0_callback default_error_callback = {
|
|
rustsecp256k1_v0_5_0_default_error_callback_fn,
|
|
NULL
|
|
};
|
|
|
|
|
|
#ifdef DETERMINISTIC
|
|
#define TEST_FAILURE(msg) do { \
|
|
fprintf(stderr, "%s\n", msg); \
|
|
abort(); \
|
|
} while(0);
|
|
#else
|
|
#define TEST_FAILURE(msg) do { \
|
|
fprintf(stderr, "%s:%d: %s\n", __FILE__, __LINE__, msg); \
|
|
abort(); \
|
|
} while(0)
|
|
#endif
|
|
|
|
#if SECP256K1_GNUC_PREREQ(3, 0)
|
|
#define EXPECT(x,c) __builtin_expect((x),(c))
|
|
#else
|
|
#define EXPECT(x,c) (x)
|
|
#endif
|
|
|
|
#ifdef DETERMINISTIC
|
|
#define CHECK(cond) do { \
|
|
if (EXPECT(!(cond), 0)) { \
|
|
TEST_FAILURE("test condition failed"); \
|
|
} \
|
|
} while(0)
|
|
#else
|
|
#define CHECK(cond) do { \
|
|
if (EXPECT(!(cond), 0)) { \
|
|
TEST_FAILURE("test condition failed: " #cond); \
|
|
} \
|
|
} while(0)
|
|
#endif
|
|
|
|
/* Like assert(), but when VERIFY is defined, and side-effect safe. */
|
|
#if defined(COVERAGE)
|
|
#define VERIFY_CHECK(check)
|
|
#define VERIFY_SETUP(stmt)
|
|
#elif defined(VERIFY)
|
|
#define VERIFY_CHECK CHECK
|
|
#define VERIFY_SETUP(stmt) do { stmt; } while(0)
|
|
#else
|
|
#define VERIFY_CHECK(cond) do { (void)(cond); } while(0)
|
|
#define VERIFY_SETUP(stmt)
|
|
#endif
|
|
|
|
/* Define `VG_UNDEF` and `VG_CHECK` when VALGRIND is defined */
|
|
#if !defined(VG_CHECK)
|
|
# if defined(VALGRIND)
|
|
# include <valgrind/memcheck.h>
|
|
# define VG_UNDEF(x,y) VALGRIND_MAKE_MEM_UNDEFINED((x),(y))
|
|
# define VG_CHECK(x,y) VALGRIND_CHECK_MEM_IS_DEFINED((x),(y))
|
|
# else
|
|
# define VG_UNDEF(x,y)
|
|
# define VG_CHECK(x,y)
|
|
# endif
|
|
#endif
|
|
|
|
/* Like `VG_CHECK` but on VERIFY only */
|
|
#if defined(VERIFY)
|
|
#define VG_CHECK_VERIFY(x,y) VG_CHECK((x), (y))
|
|
#else
|
|
#define VG_CHECK_VERIFY(x,y)
|
|
#endif
|
|
|
|
#if defined(__BIGGEST_ALIGNMENT__)
|
|
#define ALIGNMENT __BIGGEST_ALIGNMENT__
|
|
#else
|
|
/* Using 16 bytes alignment because common architectures never have alignment
|
|
* requirements above 8 for any of the types we care about. In addition we
|
|
* leave some room because currently we don't care about a few bytes. */
|
|
#define ALIGNMENT 16
|
|
#endif
|
|
|
|
#define ROUND_TO_ALIGN(size) ((((size) + ALIGNMENT - 1) / ALIGNMENT) * ALIGNMENT)
|
|
|
|
/* Macro for restrict, when available and not in a VERIFY build. */
|
|
#if defined(SECP256K1_BUILD) && defined(VERIFY)
|
|
# define SECP256K1_RESTRICT
|
|
#else
|
|
# if (!defined(__STDC_VERSION__) || (__STDC_VERSION__ < 199901L) )
|
|
# if SECP256K1_GNUC_PREREQ(3,0)
|
|
# define SECP256K1_RESTRICT __restrict__
|
|
# elif (defined(_MSC_VER) && _MSC_VER >= 1400)
|
|
# define SECP256K1_RESTRICT __restrict
|
|
# else
|
|
# define SECP256K1_RESTRICT
|
|
# endif
|
|
# else
|
|
# define SECP256K1_RESTRICT restrict
|
|
# endif
|
|
#endif
|
|
|
|
#if defined(_WIN32)
|
|
# define I64FORMAT "I64d"
|
|
# define I64uFORMAT "I64u"
|
|
#else
|
|
# define I64FORMAT "lld"
|
|
# define I64uFORMAT "llu"
|
|
#endif
|
|
|
|
#if defined(__GNUC__)
|
|
# define SECP256K1_GNUC_EXT __extension__
|
|
#else
|
|
# define SECP256K1_GNUC_EXT
|
|
#endif
|
|
|
|
/* If SECP256K1_{LITTLE,BIG}_ENDIAN is not explicitly provided, infer from various other system macros. */
|
|
#if !defined(SECP256K1_LITTLE_ENDIAN) && !defined(SECP256K1_BIG_ENDIAN)
|
|
/* Inspired by https://github.com/rofl0r/endianness.h/blob/9853923246b065a3b52d2c43835f3819a62c7199/endianness.h#L52L73 */
|
|
# if (defined(__BYTE_ORDER__) && defined(__ORDER_LITTLE_ENDIAN__) && __BYTE_ORDER__ == __ORDER_LITTLE_ENDIAN__) || \
|
|
defined(_X86_) || defined(__x86_64__) || defined(__i386__) || \
|
|
defined(__i486__) || defined(__i586__) || defined(__i686__) || \
|
|
defined(__MIPSEL) || defined(_MIPSEL) || defined(MIPSEL) || \
|
|
defined(__ARMEL__) || defined(__AARCH64EL__) || \
|
|
(defined(__LITTLE_ENDIAN__) && __LITTLE_ENDIAN__ == 1) || \
|
|
(defined(_LITTLE_ENDIAN) && _LITTLE_ENDIAN == 1) || \
|
|
defined(_M_IX86) || defined(_M_AMD64) || defined(_M_ARM) /* MSVC */
|
|
# define SECP256K1_LITTLE_ENDIAN
|
|
# endif
|
|
# if (defined(__BYTE_ORDER__) && defined(__ORDER_BIG_ENDIAN__) && __BYTE_ORDER__ == __ORDER_BIG_ENDIAN__) || \
|
|
defined(__MIPSEB) || defined(_MIPSEB) || defined(MIPSEB) || \
|
|
defined(__MICROBLAZEEB__) || defined(__ARMEB__) || defined(__AARCH64EB__) || \
|
|
(defined(__BIG_ENDIAN__) && __BIG_ENDIAN__ == 1) || \
|
|
(defined(_BIG_ENDIAN) && _BIG_ENDIAN == 1)
|
|
# define SECP256K1_BIG_ENDIAN
|
|
# endif
|
|
#endif
|
|
#if defined(SECP256K1_LITTLE_ENDIAN) == defined(SECP256K1_BIG_ENDIAN)
|
|
# error Please make sure that either SECP256K1_LITTLE_ENDIAN or SECP256K1_BIG_ENDIAN is set, see src/util.h.
|
|
#endif
|
|
|
|
/* Zero memory if flag == 1. Flag must be 0 or 1. Constant time. */
|
|
static SECP256K1_INLINE void rustsecp256k1_v0_5_0_memczero(void *s, size_t len, int flag) {
|
|
unsigned char *p = (unsigned char *)s;
|
|
/* Access flag with a volatile-qualified lvalue.
|
|
This prevents clang from figuring out (after inlining) that flag can
|
|
take only be 0 or 1, which leads to variable time code. */
|
|
volatile int vflag = flag;
|
|
unsigned char mask = -(unsigned char) vflag;
|
|
while (len) {
|
|
*p &= ~mask;
|
|
p++;
|
|
len--;
|
|
}
|
|
}
|
|
|
|
/** Semantics like memcmp. Variable-time.
|
|
*
|
|
* We use this to avoid possible compiler bugs with memcmp, e.g.
|
|
* https://gcc.gnu.org/bugzilla/show_bug.cgi?id=95189
|
|
*/
|
|
static SECP256K1_INLINE int rustsecp256k1_v0_5_0_memcmp_var(const void *s1, const void *s2, size_t n) {
|
|
const unsigned char *p1 = s1, *p2 = s2;
|
|
size_t i;
|
|
|
|
for (i = 0; i < n; i++) {
|
|
int diff = p1[i] - p2[i];
|
|
if (diff != 0) {
|
|
return diff;
|
|
}
|
|
}
|
|
return 0;
|
|
}
|
|
|
|
/** If flag is true, set *r equal to *a; otherwise leave it. Constant-time. Both *r and *a must be initialized and non-negative.*/
|
|
static SECP256K1_INLINE void rustsecp256k1_v0_5_0_int_cmov(int *r, const int *a, int flag) {
|
|
unsigned int mask0, mask1, r_masked, a_masked;
|
|
/* Access flag with a volatile-qualified lvalue.
|
|
This prevents clang from figuring out (after inlining) that flag can
|
|
take only be 0 or 1, which leads to variable time code. */
|
|
volatile int vflag = flag;
|
|
|
|
/* Casting a negative int to unsigned and back to int is implementation defined behavior */
|
|
VERIFY_CHECK(*r >= 0 && *a >= 0);
|
|
|
|
mask0 = (unsigned int)vflag + ~0u;
|
|
mask1 = ~mask0;
|
|
r_masked = ((unsigned int)*r & mask0);
|
|
a_masked = ((unsigned int)*a & mask1);
|
|
|
|
*r = (int)(r_masked | a_masked);
|
|
}
|
|
|
|
/* If USE_FORCE_WIDEMUL_{INT128,INT64} is set, use that wide multiplication implementation.
|
|
* Otherwise use the presence of __SIZEOF_INT128__ to decide.
|
|
*/
|
|
#if defined(USE_FORCE_WIDEMUL_INT128)
|
|
# define SECP256K1_WIDEMUL_INT128 1
|
|
#elif defined(USE_FORCE_WIDEMUL_INT64)
|
|
# define SECP256K1_WIDEMUL_INT64 1
|
|
#elif defined(UINT128_MAX) || defined(__SIZEOF_INT128__)
|
|
# define SECP256K1_WIDEMUL_INT128 1
|
|
#else
|
|
# define SECP256K1_WIDEMUL_INT64 1
|
|
#endif
|
|
#if defined(SECP256K1_WIDEMUL_INT128)
|
|
# if !defined(UINT128_MAX) && defined(__SIZEOF_INT128__)
|
|
SECP256K1_GNUC_EXT typedef unsigned __int128 uint128_t;
|
|
SECP256K1_GNUC_EXT typedef __int128 int128_t;
|
|
#define UINT128_MAX ((uint128_t)(-1))
|
|
#define INT128_MAX ((int128_t)(UINT128_MAX >> 1))
|
|
#define INT128_MIN (-INT128_MAX - 1)
|
|
/* No (U)INT128_C macros because compilers providing __int128 do not support 128-bit literals. */
|
|
# endif
|
|
#endif
|
|
|
|
#ifndef __has_builtin
|
|
#define __has_builtin(x) 0
|
|
#endif
|
|
|
|
/* Determine the number of trailing zero bits in a (non-zero) 32-bit x.
|
|
* This function is only intended to be used as fallback for
|
|
* rustsecp256k1_v0_5_0_ctz32_var, but permits it to be tested separately. */
|
|
static SECP256K1_INLINE int rustsecp256k1_v0_5_0_ctz32_var_debruijn(uint32_t x) {
|
|
static const uint8_t debruijn[32] = {
|
|
0x00, 0x01, 0x02, 0x18, 0x03, 0x13, 0x06, 0x19, 0x16, 0x04, 0x14, 0x0A,
|
|
0x10, 0x07, 0x0C, 0x1A, 0x1F, 0x17, 0x12, 0x05, 0x15, 0x09, 0x0F, 0x0B,
|
|
0x1E, 0x11, 0x08, 0x0E, 0x1D, 0x0D, 0x1C, 0x1B
|
|
};
|
|
return debruijn[((x & -x) * 0x04D7651F) >> 27];
|
|
}
|
|
|
|
/* Determine the number of trailing zero bits in a (non-zero) 64-bit x.
|
|
* This function is only intended to be used as fallback for
|
|
* rustsecp256k1_v0_5_0_ctz64_var, but permits it to be tested separately. */
|
|
static SECP256K1_INLINE int rustsecp256k1_v0_5_0_ctz64_var_debruijn(uint64_t x) {
|
|
static const uint8_t debruijn[64] = {
|
|
0, 1, 2, 53, 3, 7, 54, 27, 4, 38, 41, 8, 34, 55, 48, 28,
|
|
62, 5, 39, 46, 44, 42, 22, 9, 24, 35, 59, 56, 49, 18, 29, 11,
|
|
63, 52, 6, 26, 37, 40, 33, 47, 61, 45, 43, 21, 23, 58, 17, 10,
|
|
51, 25, 36, 32, 60, 20, 57, 16, 50, 31, 19, 15, 30, 14, 13, 12
|
|
};
|
|
return debruijn[((x & -x) * 0x022FDD63CC95386D) >> 58];
|
|
}
|
|
|
|
/* Determine the number of trailing zero bits in a (non-zero) 32-bit x. */
|
|
static SECP256K1_INLINE int rustsecp256k1_v0_5_0_ctz32_var(uint32_t x) {
|
|
VERIFY_CHECK(x != 0);
|
|
#if (__has_builtin(__builtin_ctz) || SECP256K1_GNUC_PREREQ(3,4))
|
|
/* If the unsigned type is sufficient to represent the largest uint32_t, consider __builtin_ctz. */
|
|
if (((unsigned)UINT32_MAX) == UINT32_MAX) {
|
|
return __builtin_ctz(x);
|
|
}
|
|
#endif
|
|
#if (__has_builtin(__builtin_ctzl) || SECP256K1_GNUC_PREREQ(3,4))
|
|
/* Otherwise consider __builtin_ctzl (the unsigned long type is always at least 32 bits). */
|
|
return __builtin_ctzl(x);
|
|
#else
|
|
/* If no suitable CTZ builtin is available, use a (variable time) software emulation. */
|
|
return rustsecp256k1_v0_5_0_ctz32_var_debruijn(x);
|
|
#endif
|
|
}
|
|
|
|
/* Determine the number of trailing zero bits in a (non-zero) 64-bit x. */
|
|
static SECP256K1_INLINE int rustsecp256k1_v0_5_0_ctz64_var(uint64_t x) {
|
|
VERIFY_CHECK(x != 0);
|
|
#if (__has_builtin(__builtin_ctzl) || SECP256K1_GNUC_PREREQ(3,4))
|
|
/* If the unsigned long type is sufficient to represent the largest uint64_t, consider __builtin_ctzl. */
|
|
if (((unsigned long)UINT64_MAX) == UINT64_MAX) {
|
|
return __builtin_ctzl(x);
|
|
}
|
|
#endif
|
|
#if (__has_builtin(__builtin_ctzll) || SECP256K1_GNUC_PREREQ(3,4))
|
|
/* Otherwise consider __builtin_ctzll (the unsigned long long type is always at least 64 bits). */
|
|
return __builtin_ctzll(x);
|
|
#else
|
|
/* If no suitable CTZ builtin is available, use a (variable time) software emulation. */
|
|
return rustsecp256k1_v0_5_0_ctz64_var_debruijn(x);
|
|
#endif
|
|
}
|
|
|
|
#endif /* SECP256K1_UTIL_H */
|