Mercurial > dropbear
view bn_mp_get_int.c @ 387:4663ced4968f libtommath-dropbear
propagate from branch 'au.asn.ucc.matt.ltm.orig' (head 1c2b7d389d0682caf980235dad97493e3206389c)
to branch 'au.asn.ucc.matt.ltm.dropbear' (head 40ab3795de3a6157f34e52ed3f0be3eebe9a2eaa)
author | Matt Johnston <matt@ucc.asn.au> |
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date | Thu, 11 Jan 2007 03:13:04 +0000 |
parents | 97db060d0ef5 |
children |
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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, [email protected], 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 $ */