tommath/bn_mp_to_unsigned_bin.c
2017-09-20 16:59:43 +02:00

49 lines
1.2 KiB
C

#include <tommath_private.h>
#ifdef BN_MP_TO_UNSIGNED_BIN_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.
*
* Tom St Denis, tstdenis82@gmail.com, http://libtom.org
*/
/* store in unsigned [big endian] format */
int mp_to_unsigned_bin(const mp_int *a, unsigned char *b)
{
int x, res;
mp_int t;
if ((res = mp_init_copy(&t, a)) != MP_OKAY) {
return res;
}
x = 0;
while (mp_iszero(&t) == MP_NO) {
#ifndef MP_8BIT
b[x++] = (unsigned char)(t.dp[0] & 255);
#else
b[x++] = (unsigned char)(t.dp[0] | ((t.dp[1] & 0x01) << 7));
#endif
if ((res = mp_div_2d(&t, 8, &t, NULL)) != MP_OKAY) {
mp_clear(&t);
return res;
}
}
bn_reverse(b, x);
mp_clear(&t);
return MP_OKAY;
}
#endif
/* ref: $Format:%D$ */
/* git commit: $Format:%H$ */
/* commit time: $Format:%ai$ */