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#include "tommath_private.h"
#ifdef BN_MP_IMPORT_C
/* 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
*/
/* based on gmp's mpz_import.
* see http://gmplib.org/manual/Integer-Import-and-Export.html
*/
int mp_import(mp_int *rop, size_t count, int order, size_t size,
int endian, size_t nails, const void *op)
{
int result;
size_t odd_nails, nail_bytes, i, j;
unsigned char odd_nail_mask;
mp_zero(rop);
if (endian == 0) {
union {
unsigned int i;
char c[4];
} lint;
lint.i = 0x01020304;
endian = (lint.c[0] == '\x04') ? -1 : 1;
}
odd_nails = (nails % 8u);
odd_nail_mask = 0xff;
for (i = 0; i < odd_nails; ++i) {
odd_nail_mask ^= (unsigned char)(1u << (7u - i));
}
nail_bytes = nails / 8u;
for (i = 0; i < count; ++i) {
for (j = 0; j < (size - nail_bytes); ++j) {
unsigned char byte = *((unsigned char *)op +
(((order == 1) ? i : ((count - 1u) - i)) * size) +
((endian == 1) ? (j + nail_bytes) : (((size - 1u) - j) - nail_bytes)));
if ((result = mp_mul_2d(rop, (j == 0u) ? (int)(8u - odd_nails) : 8, rop)) != MP_OKAY) {
return result;
}
rop->dp[0] |= (j == 0u) ? (mp_digit)(byte & odd_nail_mask) : (mp_digit)byte;
rop->used += 1;
}
}
mp_clamp(rop);
return MP_OKAY;
}
#endif
/* ref: $Format:%D$ */
/* git commit: $Format:%H$ */
/* commit time: $Format:%ai$ */
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