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author | Matt Johnston <matt@ucc.asn.au> | 2006-03-08 13:23:49 +0000 |
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committer | Matt Johnston <matt@ucc.asn.au> | 2006-03-08 13:23:49 +0000 |
commit | 8608a8e64c1aeda096867f43f89e29e1aee207ae (patch) | |
tree | 453ebf8873dd287a2def6a674d42afcc6637cde2 /libtommath/bn_mp_reduce_setup.c | |
parent | 2481693cf23dba90c693762a528d2923cde9c9cc (diff) | |
parent | 882a9ced901348b3a48023443bfd23e0ef9d9b67 (diff) |
propagate from branch 'au.asn.ucc.matt.ltm.dropbear' (head 6c790cad5a7fa866ad062cb3a0c279f7ba788583)
to branch 'au.asn.ucc.matt.dropbear' (head fff0894a0399405a9410ea1c6d118f342cf2aa64)
--HG--
extra : convert_revision : fdf4a7a3b97ae5046139915de7e40399cceb2c01
Diffstat (limited to 'libtommath/bn_mp_reduce_setup.c')
-rw-r--r-- | libtommath/bn_mp_reduce_setup.c | 30 |
1 files changed, 30 insertions, 0 deletions
diff --git a/libtommath/bn_mp_reduce_setup.c b/libtommath/bn_mp_reduce_setup.c new file mode 100644 index 0000000..99f158a --- /dev/null +++ b/libtommath/bn_mp_reduce_setup.c @@ -0,0 +1,30 @@ +#include <tommath.h> +#ifdef BN_MP_REDUCE_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@iahu.ca, http://math.libtomcrypt.org + */ + +/* pre-calculate the value required for Barrett reduction + * For a given modulus "b" it calulates the value required in "a" + */ +int mp_reduce_setup (mp_int * a, mp_int * b) +{ + int res; + + if ((res = mp_2expt (a, b->used * 2 * DIGIT_BIT)) != MP_OKAY) { + return res; + } + return mp_div (a, b, a, NULL); +} +#endif |