70 lines
1.9 KiB
C
70 lines
1.9 KiB
C
#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.
|
|
*
|
|
* The library is free for all purposes without any express
|
|
* guarantee it works.
|
|
*/
|
|
|
|
/* 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: $Format:%ai$ */
|