26 lines
635 B
C
26 lines
635 B
C
#include "tommath_private.h"
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#ifdef BN_MP_FROM_SBIN_C
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/* LibTomMath, multiple-precision integer library -- Tom St Denis */
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/* SPDX-License-Identifier: Unlicense */
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/* read signed bin, big endian, first byte is 0==positive or 1==negative */
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mp_err mp_from_sbin(mp_int *a, const unsigned char *buf, size_t size)
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{
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mp_err err;
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/* read magnitude */
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if ((err = mp_from_ubin(a, buf + 1, size - 1u)) != MP_OKAY) {
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return err;
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}
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/* first byte is 0 for positive, non-zero for negative */
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if (buf[0] == (unsigned char)0) {
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a->sign = MP_ZPOS;
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} else {
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a->sign = MP_NEG;
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}
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return MP_OKAY;
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}
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#endif
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