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author | Ladislav Zezula <ladislav.zezula@avg.com> | 2013-01-11 14:55:08 +0100 |
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committer | Ladislav Zezula <ladislav.zezula@avg.com> | 2013-01-11 14:55:08 +0100 |
commit | 3a926f0228c68d7d91cf3946624d7859976440ec (patch) | |
tree | c4e7d36dc8157576929988cdfcf5bfd8262cd09c /src/libtommath/bn_mp_rand.c | |
parent | df4b0c085478389c9a21a09521d46735a0109c8a (diff) |
Initial creation
Diffstat (limited to 'src/libtommath/bn_mp_rand.c')
-rw-r--r-- | src/libtommath/bn_mp_rand.c | 55 |
1 files changed, 55 insertions, 0 deletions
diff --git a/src/libtommath/bn_mp_rand.c b/src/libtommath/bn_mp_rand.c new file mode 100644 index 0000000..e124178 --- /dev/null +++ b/src/libtommath/bn_mp_rand.c @@ -0,0 +1,55 @@ +#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, tomstdenis@gmail.com, http://libtom.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 + +/* $Source: /cvs/libtom/libtommath/bn_mp_rand.c,v $ */ +/* $Revision: 1.4 $ */ +/* $Date: 2006/12/28 01:25:13 $ */ |