Mercurial > dropbear
view libtommath/bn_mp_get_int.c @ 607:aa2f51a6b81d DROPBEAR_0.53.1
Update changelog for 0.53.1
author | Matt Johnston <matt@ucc.asn.au> |
---|---|
date | Wed, 02 Mar 2011 13:23:27 +0000 (2011-03-02) |
parents | 5ff8218bcee9 |
children | 60fc6476e044 |
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#include <tommath.h> #ifdef BN_MP_GET_INT_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, tomstdenis@gmail.com, http://math.libtomcrypt.com */ /* get the lower 32-bits of an mp_int */ unsigned long mp_get_int(mp_int * a) { int i; unsigned long res; if (a->used == 0) { return 0; } /* get number of digits of the lsb we have to read */ i = MIN(a->used,(int)((sizeof(unsigned long)*CHAR_BIT+DIGIT_BIT-1)/DIGIT_BIT))-1; /* get most significant digit of result */ res = DIGIT(a,i); while (--i >= 0) { res = (res << DIGIT_BIT) | DIGIT(a,i); } /* force result to 32-bits always so it is consistent on non 32-bit platforms */ return res & 0xFFFFFFFFUL; } #endif /* $Source: /cvs/libtom/libtommath/bn_mp_get_int.c,v $ */ /* $Revision: 1.3 $ */ /* $Date: 2006/03/31 14:18:44 $ */