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author | Nikos Mavrogiannopoulos <nmav@gnutls.org> | 2010-07-05 10:53:45 +0200 |
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committer | Nikos Mavrogiannopoulos <nmav@gnutls.org> | 2010-07-05 10:57:27 +0200 |
commit | 22db48330c452c35e3981f10b5bd6cc49ce59526 (patch) | |
tree | 5e90f7aa9f228adc99b2a4486a10a6691dad4830 /libtommath/bn_mp_reduce_2k_setup.c | |
parent | aaadfeb4517b66bbd59de39173f2d032aa1d8ea9 (diff) | |
download | cryptodev-linux-22db48330c452c35e3981f10b5bd6cc49ce59526.tar.gz cryptodev-linux-22db48330c452c35e3981f10b5bd6cc49ce59526.tar.xz cryptodev-linux-22db48330c452c35e3981f10b5bd6cc49ce59526.zip |
Added libtommath for bignum operations.
Diffstat (limited to 'libtommath/bn_mp_reduce_2k_setup.c')
-rw-r--r-- | libtommath/bn_mp_reduce_2k_setup.c | 47 |
1 files changed, 47 insertions, 0 deletions
diff --git a/libtommath/bn_mp_reduce_2k_setup.c b/libtommath/bn_mp_reduce_2k_setup.c new file mode 100644 index 0000000..a80e7a2 --- /dev/null +++ b/libtommath/bn_mp_reduce_2k_setup.c @@ -0,0 +1,47 @@ +#include <tommath.h> +#ifdef BN_MP_REDUCE_2K_SETUP_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 + */ + +/* determines the setup value */ +int mp_reduce_2k_setup(mp_int *a, mp_digit *d) +{ + int res, p; + mp_int tmp; + + if ((res = mp_init(&tmp)) != MP_OKAY) { + return res; + } + + p = mp_count_bits(a); + if ((res = mp_2expt(&tmp, p)) != MP_OKAY) { + mp_clear(&tmp); + return res; + } + + if ((res = s_mp_sub(&tmp, a, &tmp)) != MP_OKAY) { + mp_clear(&tmp); + return res; + } + + *d = tmp.dp[0]; + mp_clear(&tmp); + return MP_OKAY; +} +#endif + +/* $Source: /cvs/libtom/libtommath/bn_mp_reduce_2k_setup.c,v $ */ +/* $Revision: 1.4 $ */ +/* $Date: 2006/12/28 01:25:13 $ */ |