libtommath/tommath_private.h

/* LibTomMath, multiple-precision integer library -- Tom St Denis
 *
 * LibTomMath is a library that provides multiple-precision
 * integer arithmetic as well as number theoretic functionality.
 *
 * The library was designed directly after the MPI library by
 * Michael Fromberger but has been written from scratch with
 * additional optimizations in place.
 *
 * SPDX-License-Identifier: Unlicense
 */
#ifndef TOMMATH_PRIV_H_
#define TOMMATH_PRIV_H_

#include "tommath.h"

#ifndef MIN
#define MIN(x, y) (((x) < (y)) ? (x) : (y))
#endif

#ifndef MAX
#define MAX(x, y) (((x) > (y)) ? (x) : (y))
#endif

#ifdef __cplusplus
extern "C" {
#endif

/* define heap macros */
#ifndef XMALLOC
/* default to libc stuff */
#   define XMALLOC(size)                   malloc(size)
#   define XREALLOC(mem, oldsize, newsize) realloc(mem, newsize)
#   define XCALLOC(nmemb, size)            calloc(nmemb, size)
#   define XFREE(mem, size)                free(mem)
#else
/* prototypes for our heap functions */
extern void *XMALLOC(size_t size);
extern void *XREALLOC(void *mem, size_t oldsize, size_t newsize);
extern void *XCALLOC(size_t nmemb, size_t size);
extern void XFREE(void *mem, size_t size);
#endif

/* ---> Basic Manipulations <--- */
#define IS_ZERO(a) ((a)->used == 0)
#define IS_EVEN(a) (((a)->used == 0) || (((a)->dp[0] & 1u) == 0u))
#define IS_ODD(a)  (((a)->used > 0) && (((a)->dp[0] & 1u) == 1u))

/* lowlevel functions, do not call! */
int s_mp_add(const mp_int *a, const mp_int *b, mp_int *c);
int s_mp_sub(const mp_int *a, const mp_int *b, mp_int *c);
#define s_mp_mul(a, b, c) s_mp_mul_digs(a, b, c, (a)->used + (b)->used + 1)
int fast_s_mp_mul_digs(const mp_int *a, const mp_int *b, mp_int *c, int digs);
int s_mp_mul_digs(const mp_int *a, const mp_int *b, mp_int *c, int digs);
int fast_s_mp_mul_high_digs(const mp_int *a, const mp_int *b, mp_int *c, int digs);
int s_mp_mul_high_digs(const mp_int *a, const mp_int *b, mp_int *c, int digs);
int fast_s_mp_sqr(const mp_int *a, mp_int *b);
int s_mp_sqr(const mp_int *a, mp_int *b);
int mp_karatsuba_mul(const mp_int *a, const mp_int *b, mp_int *c);
int mp_toom_mul(const mp_int *a, const mp_int *b, mp_int *c);
int mp_karatsuba_sqr(const mp_int *a, mp_int *b);
int mp_toom_sqr(const mp_int *a, mp_int *b);
int fast_mp_invmod(const mp_int *a, const mp_int *b, mp_int *c);
int mp_invmod_slow(const mp_int *a, const mp_int *b, mp_int *c);
int fast_mp_montgomery_reduce(mp_int *x, const mp_int *n, mp_digit rho);
int mp_exptmod_fast(const mp_int *G, const mp_int *X, const mp_int *P, mp_int *Y, int redmode);
int s_mp_exptmod(const mp_int *G, const mp_int *X, const mp_int *P, mp_int *Y, int redmode);
void bn_reverse(unsigned char *s, int len);

extern const char *const mp_s_rmap;
extern const uint8_t mp_s_rmap_reverse[];
extern const size_t mp_s_rmap_reverse_sz;

/* Fancy macro to set an MPI from another type.
 * There are several things assumed:
 *  x is the counter
 *  a is the pointer to the MPI
 *  b is the original value that should be set in the MPI.
 */
#define MP_SET_XLONG(func_name, type)                    \
int func_name (mp_int * a, type b)                       \
{                                                        \
   int x = 0;                                            \
   int new_size = (((CHAR_BIT * sizeof(type)) + DIGIT_BIT) - 1) / DIGIT_BIT; \
   int res = mp_grow(a, new_size);                       \
   if (res == MP_OKAY) {                                 \
     mp_zero(a);                                         \
     while (b != 0u) {                                   \
        a->dp[x++] = ((mp_digit)b & MP_MASK);            \
        if ((CHAR_BIT * sizeof (b)) <= DIGIT_BIT) { break; } \
        b >>= ((CHAR_BIT * sizeof (b)) <= DIGIT_BIT ? 0 : DIGIT_BIT); \
     }                                                   \
     a->used = x;                                        \
   }                                                     \
   return res;                                           \
}

#ifdef __cplusplus
}
#endif

#endif