Mercurial > dropbear
diff libtommath/bn_mp_read_unsigned_bin.c @ 302:973fccb59ea4 ucc-axis-hack
propagate from branch 'au.asn.ucc.matt.dropbear' (head 11034278bd1917bebcbdc69cf53b1891ce9db121)
to branch 'au.asn.ucc.matt.dropbear.ucc-axis-hack' (head 10a1f614fec73d0820c3f61160d9db409b9beb46)
author | Matt Johnston <matt@ucc.asn.au> |
---|---|
date | Sat, 25 Mar 2006 12:59:58 +0000 |
parents | eed26cff980b |
children | 5ff8218bcee9 |
line wrap: on
line diff
--- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/libtommath/bn_mp_read_unsigned_bin.c Sat Mar 25 12:59:58 2006 +0000 @@ -0,0 +1,52 @@ +#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.org + */ + +/* reads a unsigned char array, assumes the msb is stored first [big endian] */ +int +mp_read_unsigned_bin (mp_int * a, 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