301 lines
13 KiB
C
301 lines
13 KiB
C
/* LibTomMath, multiple-precision integer library -- Tom St Denis */
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/* SPDX-License-Identifier: Unlicense */
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#ifndef TOMMATH_PRIVATE_H_
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#define TOMMATH_PRIVATE_H_
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#include "tommath.h"
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#include "tommath_class.h"
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#include <limits.h>
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/*
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* Private symbols
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* ---------------
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*
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* On Unix symbols can be marked as hidden if libtommath is compiled
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* as a shared object. By default, symbols are visible.
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* On Win32 a .def file must be used to specify the exported symbols.
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*/
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#if defined(__GNUC__) && __GNUC__ >= 4 && !defined(_WIN32) && !defined(__CYGWIN__)
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# define MP_PRIVATE __attribute__ ((visibility ("hidden")))
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#else
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# define MP_PRIVATE
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#endif
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/* Hardening libtommath
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* --------------------
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*
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* By default memory is zeroed before calling
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* MP_FREE to avoid leaking data. This is good
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* practice in cryptographical applications.
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*
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* Note however that memory allocators used
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* in cryptographical applications can often
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* be configured by itself to clear memory,
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* rendering the clearing in tommath unnecessary.
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* See for example https://github.com/GrapheneOS/hardened_malloc
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* and the option CONFIG_ZERO_ON_FREE.
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*
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* Furthermore there are applications which
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* value performance more and want this
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* feature to be disabled. For such applications
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* define MP_NO_ZERO_ON_FREE during compilation.
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*/
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#ifdef MP_NO_ZERO_ON_FREE
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# define MP_FREE_BUF(mem, size) MP_FREE((mem), (size))
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# define MP_FREE_DIGS(mem, digits) MP_FREE((mem), sizeof (mp_digit) * (size_t)(digits))
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#else
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# define MP_FREE_BUF(mem, size) \
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do { \
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size_t fs_ = (size); \
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void* fm_ = (mem); \
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if (fm_ != NULL) { \
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s_mp_zero_buf(fm_, fs_); \
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MP_FREE(fm_, fs_); \
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} \
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} while (0)
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# define MP_FREE_DIGS(mem, digits) \
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do { \
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int fd_ = (digits); \
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mp_digit* fm_ = (mem); \
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if (fm_ != NULL) { \
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s_mp_zero_digs(fm_, fd_); \
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MP_FREE(fm_, sizeof (mp_digit) * (size_t)fd_); \
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} \
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} while (0)
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#endif
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/* Tunable cutoffs
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* ---------------
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*
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* - In the default settings, a cutoff X can be modified at runtime
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* by adjusting the corresponding X_CUTOFF variable.
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*
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* - Tunability of the library can be disabled at compile time
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* by defining the MP_FIXED_CUTOFFS macro.
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*
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* - There is an additional file tommath_cutoffs.h, which defines
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* the default cutoffs. These can be adjusted manually or by the
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* autotuner.
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*
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*/
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#ifdef MP_FIXED_CUTOFFS
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# include "tommath_cutoffs.h"
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# define MP_MUL_KARATSUBA_CUTOFF MP_DEFAULT_MUL_KARATSUBA_CUTOFF
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# define MP_SQR_KARATSUBA_CUTOFF MP_DEFAULT_SQR_KARATSUBA_CUTOFF
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# define MP_MUL_TOOM_CUTOFF MP_DEFAULT_MUL_TOOM_CUTOFF
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# define MP_SQR_TOOM_CUTOFF MP_DEFAULT_SQR_TOOM_CUTOFF
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#endif
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/* define heap macros */
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#ifndef MP_MALLOC
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/* default to libc stuff */
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# include <stdlib.h>
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# define MP_MALLOC(size) malloc(size)
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# define MP_REALLOC(mem, oldsize, newsize) realloc((mem), (newsize))
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# define MP_CALLOC(nmemb, size) calloc((nmemb), (size))
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# define MP_FREE(mem, size) free(mem)
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#else
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/* prototypes for our heap functions */
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extern void *MP_MALLOC(size_t size);
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extern void *MP_REALLOC(void *mem, size_t oldsize, size_t newsize);
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extern void *MP_CALLOC(size_t nmemb, size_t size);
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extern void MP_FREE(void *mem, size_t size);
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#endif
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/* feature detection macro */
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#ifdef _MSC_VER
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/* Prevent false positive: not enough arguments for function-like macro invocation */
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#pragma warning(disable: 4003)
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#endif
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#define MP_STRINGIZE(x) MP__STRINGIZE(x)
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#define MP__STRINGIZE(x) ""#x""
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#define MP_HAS(x) (sizeof(MP_STRINGIZE(x##_C)) == 1u)
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#define MP_MIN(x, y) (((x) < (y)) ? (x) : (y))
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#define MP_MAX(x, y) (((x) > (y)) ? (x) : (y))
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#define MP_TOUPPER(c) ((((c) >= 'a') && ((c) <= 'z')) ? (((c) + 'A') - 'a') : (c))
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#define MP_EXCH(t, a, b) do { t _c = a; a = b; b = _c; } while (0)
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#define MP_IS_2EXPT(x) (((x) != 0u) && (((x) & ((x) - 1u)) == 0u))
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/* TODO: same as above for bigint, merge (is it used elsewhere?) or change name */
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#define MP_IS_POWER_OF_TWO(a) (((mp_count_bits((a)) - 1) == mp_cnt_lsb((a))) )
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/* Static assertion */
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#define MP_STATIC_ASSERT(msg, cond) typedef char mp_static_assert_##msg[(cond) ? 1 : -1];
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#define MP_SIZEOF_BITS(type) ((size_t)CHAR_BIT * sizeof(type))
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#define MP_MAX_COMBA (int)(1uL << (MP_SIZEOF_BITS(mp_word) - (2u * (size_t)MP_DIGIT_BIT)))
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#define MP_WARRAY (int)(1uL << ((MP_SIZEOF_BITS(mp_word) - (2u * (size_t)MP_DIGIT_BIT)) + 1u))
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#if defined(MP_16BIT)
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typedef uint32_t mp_word;
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#define MP_WORD_SIZE 4
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#elif ((defined (MP_64BIT)) && !(defined(MP_31BIT)) )
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typedef unsigned long mp_word __attribute__((mode(TI)));
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#define MP_WORD_SIZE 16
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#else
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typedef uint64_t mp_word;
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#define MP_WORD_SIZE 8
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#endif
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MP_STATIC_ASSERT(correct_word_size, sizeof(mp_word) == (2u * sizeof(mp_digit)))
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/* default number of digits */
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#ifndef MP_DEFAULT_DIGIT_COUNT
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# ifndef MP_LOW_MEM
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# define MP_DEFAULT_DIGIT_COUNT 32
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# else
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# define MP_DEFAULT_DIGIT_COUNT 8
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# endif
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#endif
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/* Minimum number of available digits in mp_int, MP_DEFAULT_DIGIT_COUNT >= MP_MIN_DIGIT_COUNT
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* - Must be at least 3 for s_mp_div_school.
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* - Must be large enough such that the mp_set_u64 setter can
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* store uint64_t in the mp_int without growing
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*/
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#define MP_MIN_DIGIT_COUNT MP_MAX(3, (((int)MP_SIZEOF_BITS(uint64_t) + MP_DIGIT_BIT) - 1) / MP_DIGIT_BIT)
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MP_STATIC_ASSERT(prec_geq_min_prec, MP_DEFAULT_DIGIT_COUNT >= MP_MIN_DIGIT_COUNT)
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/* Maximum number of digits.
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* - Must be small enough such that mp_bit_count does not overflow.
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* - Must be small enough such that mp_radix_size for base 2 does not overflow.
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* mp_radix_size needs two additional bytes for zero termination and sign.
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*/
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#define MP_MAX_DIGIT_COUNT ((INT_MAX - 2) / MP_DIGIT_BIT)
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#if defined(__STDC_IEC_559__) || defined(__GCC_IEC_559) \
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|| defined(__x86_64__) || defined(_M_X64) || defined(_M_AMD64) \
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|| defined(__i386__) || defined(_M_X86) || defined(_M_IX86) \
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|| defined(__aarch64__) || defined(__arm__)
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#define MP_HAS_SET_DOUBLE
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#endif
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/*
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The mp_log functions rely on the size of mp_word being larger than INT_MAX and in case
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there is a really weird architecture we try to check for it. Not a 100% reliable
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test but it has a safe fallback.
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*/
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#if !(((UINT_MAX == UINT32_MAX) && (MP_WORD_SIZE > 4)) \
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|| ((UINT_MAX == UINT16_MAX) && (MP_WORD_SIZE > 2)))
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#define S_MP_WORD_TOO_SMALL_C
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#endif
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/* random number source */
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extern MP_PRIVATE mp_err(*s_mp_rand_source)(void *out, size_t size);
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/* lowlevel functions, do not call! */
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MP_PRIVATE bool s_mp_get_bit(const mp_int *a, int b) MP_WUR;
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MP_PRIVATE int s_mp_log_2expt(const mp_int *a, mp_digit base) MP_WUR;
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MP_PRIVATE mp_err s_mp_add(const mp_int *a, const mp_int *b, mp_int *c) MP_WUR;
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MP_PRIVATE mp_err s_mp_div_3(const mp_int *a, mp_int *c, mp_digit *d) MP_WUR;
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MP_PRIVATE mp_err s_mp_div_recursive(const mp_int *a, const mp_int *b, mp_int *q, mp_int *r) MP_WUR;
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MP_PRIVATE mp_err s_mp_div_school(const mp_int *a, const mp_int *b, mp_int *c, mp_int *d) MP_WUR;
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MP_PRIVATE mp_err s_mp_div_small(const mp_int *a, const mp_int *b, mp_int *c, mp_int *d) MP_WUR;
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MP_PRIVATE mp_err s_mp_exptmod(const mp_int *G, const mp_int *X, const mp_int *P, mp_int *Y, int redmode) MP_WUR;
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MP_PRIVATE mp_err s_mp_exptmod_fast(const mp_int *G, const mp_int *X, const mp_int *P, mp_int *Y, int redmode) MP_WUR;
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MP_PRIVATE mp_err s_mp_invmod(const mp_int *a, const mp_int *b, mp_int *c) MP_WUR;
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MP_PRIVATE mp_err s_mp_invmod_odd(const mp_int *a, const mp_int *b, mp_int *c) MP_WUR;
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MP_PRIVATE mp_err s_mp_montgomery_reduce_comba(mp_int *x, const mp_int *n, mp_digit rho) MP_WUR;
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MP_PRIVATE mp_err s_mp_mul(const mp_int *a, const mp_int *b, mp_int *c, int digs) MP_WUR;
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MP_PRIVATE mp_err s_mp_mul_balance(const mp_int *a, const mp_int *b, mp_int *c) MP_WUR;
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MP_PRIVATE mp_err s_mp_mul_comba(const mp_int *a, const mp_int *b, mp_int *c, int digs) MP_WUR;
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MP_PRIVATE mp_err s_mp_mul_high(const mp_int *a, const mp_int *b, mp_int *c, int digs) MP_WUR;
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MP_PRIVATE mp_err s_mp_mul_high_comba(const mp_int *a, const mp_int *b, mp_int *c, int digs) MP_WUR;
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MP_PRIVATE mp_err s_mp_mul_karatsuba(const mp_int *a, const mp_int *b, mp_int *c) MP_WUR;
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MP_PRIVATE mp_err s_mp_mul_toom(const mp_int *a, const mp_int *b, mp_int *c) MP_WUR;
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MP_PRIVATE mp_err s_mp_prime_is_divisible(const mp_int *a, bool *result) MP_WUR;
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MP_PRIVATE mp_err s_mp_rand_platform(void *p, size_t n) MP_WUR;
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MP_PRIVATE mp_err s_mp_sqr(const mp_int *a, mp_int *b) MP_WUR;
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MP_PRIVATE mp_err s_mp_sqr_comba(const mp_int *a, mp_int *b) MP_WUR;
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MP_PRIVATE mp_err s_mp_sqr_karatsuba(const mp_int *a, mp_int *b) MP_WUR;
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MP_PRIVATE mp_err s_mp_sqr_toom(const mp_int *a, mp_int *b) MP_WUR;
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MP_PRIVATE mp_err s_mp_sub(const mp_int *a, const mp_int *b, mp_int *c) MP_WUR;
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MP_PRIVATE void s_mp_copy_digs(mp_digit *d, const mp_digit *s, int digits);
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MP_PRIVATE void s_mp_zero_buf(void *mem, size_t size);
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MP_PRIVATE void s_mp_zero_digs(mp_digit *d, int digits);
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MP_PRIVATE mp_err s_mp_radix_size_overestimate(const mp_int *a, const int radix, size_t *size);
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#define MP_PRECISION_FIXED_LOG ( (int) (((sizeof(mp_word) * CHAR_BIT) / 2) - 1))
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#define MP_UPPER_LIMIT_FIXED_LOG ( (int) ( (sizeof(mp_word) * CHAR_BIT) - 1))
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MP_PRIVATE mp_err s_mp_fp_log(const mp_int *a, mp_int *c) MP_WUR;
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MP_PRIVATE mp_err s_mp_fp_log_d(const mp_int *a, mp_word *c) MP_WUR;
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#define MP_RADIX_MAP_REVERSE_SIZE 80u
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extern MP_PRIVATE const char s_mp_radix_map[];
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extern MP_PRIVATE const uint8_t s_mp_radix_map_reverse[];
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extern MP_PRIVATE const mp_digit s_mp_prime_tab[];
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/* number of primes */
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#define MP_PRIME_TAB_SIZE 256
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#define MP_GET_ENDIANNESS(x) \
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do{\
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int16_t n = 0x1; \
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char *p = (char *)&n; \
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x = (p[0] == '\x01') ? MP_LITTLE_ENDIAN : MP_BIG_ENDIAN; \
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} while (0)
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/* code-generating macros */
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#define MP_SET_UNSIGNED(name, type) \
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void name(mp_int * a, type b) \
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{ \
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int i = 0; \
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while (b != 0u) { \
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a->dp[i++] = ((mp_digit)b & MP_MASK); \
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if (MP_SIZEOF_BITS(type) <= MP_DIGIT_BIT) { break; } \
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b >>= ((MP_SIZEOF_BITS(type) <= MP_DIGIT_BIT) ? 0 : MP_DIGIT_BIT); \
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} \
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a->used = i; \
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a->sign = MP_ZPOS; \
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s_mp_zero_digs(a->dp + a->used, a->alloc - a->used); \
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}
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#define MP_SET_SIGNED(name, uname, type, utype) \
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void name(mp_int * a, type b) \
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{ \
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uname(a, (b < 0) ? -(utype)b : (utype)b); \
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if (b < 0) { a->sign = MP_NEG; } \
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}
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#define MP_INIT_INT(name , set, type) \
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mp_err name(mp_int * a, type b) \
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{ \
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mp_err err; \
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if ((err = mp_init(a)) != MP_OKAY) { \
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return err; \
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} \
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set(a, b); \
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return MP_OKAY; \
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}
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#define MP_GET_MAG(name, type) \
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type name(const mp_int* a) \
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{ \
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int i = MP_MIN(a->used, (int)((MP_SIZEOF_BITS(type) + MP_DIGIT_BIT - 1) / MP_DIGIT_BIT)); \
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type res = 0u; \
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while (i --> 0) { \
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res <<= ((MP_SIZEOF_BITS(type) <= MP_DIGIT_BIT) ? 0 : MP_DIGIT_BIT); \
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res |= (type)a->dp[i]; \
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if (MP_SIZEOF_BITS(type) <= MP_DIGIT_BIT) { break; } \
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} \
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return res; \
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}
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#define MP_GET_SIGNED(name, mag, type, utype) \
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type name(const mp_int* a) \
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{ \
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utype res = mag(a); \
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return mp_isneg(a) ? (type)-res : (type)res; \
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}
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#endif
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