Mercurial > dropbear
view libtommath/bn_mp_read_unsigned_bin.c @ 1689:d2d3b5ba6c64
update travis to Ubuntu focal to provide chacha20
author | Matt Johnston <matt@ucc.asn.au> |
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date | Tue, 26 May 2020 23:13:48 +0800 |
parents | f52919ffd3b1 |
children |
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#include "tommath_private.h" #ifdef BN_MP_READ_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. * * SPDX-License-Identifier: Unlicense */ /* reads a unsigned char array, assumes the msb is stored first [big endian] */ int mp_read_unsigned_bin(mp_int *a, const unsigned char *b, int c) { int res; /* make sure there are at least two digits */ if (a->alloc < 2) { if ((res = mp_grow(a, 2)) != MP_OKAY) { return res; } } /* zero the int */ mp_zero(a); /* read the bytes in */ while (c-- > 0) { if ((res = mp_mul_2d(a, 8, a)) != MP_OKAY) { return res; } #ifndef MP_8BIT a->dp[0] |= *b++; a->used += 1; #else a->dp[0] = (*b & MP_MASK); a->dp[1] |= ((*b++ >> 7) & 1u); a->used += 2; #endif } mp_clamp(a); return MP_OKAY; } #endif /* ref: HEAD -> master, tag: v1.1.0 */ /* git commit: 08549ad6bc8b0cede0b357a9c341c5c6473a9c55 */ /* commit time: 2019-01-28 20:32:32 +0100 */