Mercurial > dropbear
view libtommath/bn_mp_from_ubin.c @ 1793:f90e681b8b8c
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author | Matt Johnston <matt@ucc.asn.au> |
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date | Fri, 29 Jan 2021 21:59:12 +0800 |
parents | 1051e4eea25a |
children |
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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