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#include "tommath_private.h"
#ifdef BN_MP_TO_UBIN_C
/* LibTomMath, multiple-precision integer library -- Tom St Denis */
/* SPDX-License-Identifier: Unlicense */
/* store in unsigned [big endian] format */
mp_err mp_to_ubin(const mp_int *a, unsigned char *buf, size_t maxlen, size_t *written)
{
size_t x, count;
mp_err err;
mp_int t;
size_t size = (size_t)mp_count_bits(a);
count = (size / 8u) + (((size & 7u) != 0u) ? 1u : 0u);
if (count > maxlen) {
return MP_BUF;
}
if ((err = mp_init_copy(&t, a)) != MP_OKAY) {
return err;
}
for (x = count; x --> 0u;) {
#ifndef MP_8BIT
buf[x] = (unsigned char)(t.dp[0] & 255u);
#else
buf[x] = (unsigned char)(t.dp[0] | ((t.dp[1] & 1u) << 7));
#endif
if ((err = mp_div_2d(&t, 8, &t, NULL)) != MP_OKAY) {
goto LBL_ERR;
}
}
if (written != NULL) {
*written = count;
}
LBL_ERR:
mp_clear(&t);
return err;
}
#endif
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