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#include "tommath_private.h"
#ifdef BN_MP_FROM_UBIN_C
/* LibTomMath, multiple-precision integer library -- Tom St Denis */
/* SPDX-License-Identifier: Unlicense */
/* reads a unsigned char array, assumes the msb is stored first [big endian] */
mp_err mp_from_ubin(mp_int *a, const unsigned char *buf, size_t size)
{
mp_err err;
/* make sure there are at least two digits */
if (a->alloc < 2) {
if ((err = mp_grow(a, 2)) != MP_OKAY) {
return err;
}
}
/* zero the int */
mp_zero(a);
/* read the bytes in */
while (size-- > 0u) {
if ((err = mp_mul_2d(a, 8, a)) != MP_OKAY) {
return err;
}
#ifndef MP_8BIT
a->dp[0] |= *buf++;
a->used += 1;
#else
a->dp[0] = (*buf & MP_MASK);
a->dp[1] |= ((*buf++ >> 7) & 1u);
a->used += 2;
#endif
}
mp_clamp(a);
return MP_OKAY;
}
#endif
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