Mercurial > dropbear
view bn_mp_rand.c @ 200:c5c969ed76f3 libtommath
propagate from branch 'au.asn.ucc.matt.ltm-orig' (head 7fa10cba9535de3461cedb14b877c24858826204)
to branch 'au.asn.ucc.matt.dropbear.ltm' (head fc26f60de0370ab0a281fa41a2d13fb17c9d90a8)
author | Matt Johnston <matt@ucc.asn.au> |
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date | Wed, 11 May 2005 16:15:27 +0000 |
parents | d8254fc979e9 |
children |
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#include <tommath.h> #ifdef BN_MP_RAND_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 */ /* makes a pseudo-random int of a given size */ int mp_rand (mp_int * a, int digits) { int res; mp_digit d; mp_zero (a); if (digits <= 0) { return MP_OKAY; } /* first place a random non-zero digit */ do { d = ((mp_digit) abs (rand ())) & MP_MASK; } while (d == 0); if ((res = mp_add_d (a, d, a)) != MP_OKAY) { return res; } while (--digits > 0) { if ((res = mp_lshd (a, 1)) != MP_OKAY) { return res; } if ((res = mp_add_d (a, ((mp_digit) abs (rand ())), a)) != MP_OKAY) { return res; } } return MP_OKAY; } #endif