Mercurial > dropbear
view libtommath/bn_mp_read_unsigned_bin.c @ 1200:9a944a243f08 DROPBEAR_2015.71
2015.71
author | Matt Johnston <matt@ucc.asn.au> |
---|---|
date | Thu, 03 Dec 2015 21:23:54 +0800 |
parents | 5ff8218bcee9 |
children | 60fc6476e044 |
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#include <tommath.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. * * The library is free for all purposes without any express * guarantee it works. * * Tom St Denis, [email protected], http://math.libtomcrypt.com */ /* 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++ >> 7U) & 1); a->used += 2; #endif } mp_clamp (a); return MP_OKAY; } #endif /* $Source: /cvs/libtom/libtommath/bn_mp_read_unsigned_bin.c,v $ */ /* $Revision: 1.4 $ */ /* $Date: 2006/03/31 14:18:44 $ */