diff options
author | Matt Johnston <matt@ucc.asn.au> | 2006-03-21 16:20:59 +0000 |
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committer | Matt Johnston <matt@ucc.asn.au> | 2006-03-21 16:20:59 +0000 |
commit | f7caf6f5c640cb1756c01184898f176438a3a0c2 (patch) | |
tree | 4d32de11b18d5f6296207961b5f25d0949af80c0 /libtommath/bn_mp_reduce_is_2k_l.c | |
parent | e444f0cfe67c71d3f38854f27cefae9aea6c4cd9 (diff) | |
parent | 3f49fc5f2ca0ec4adb5cac081f502cbb86702efa (diff) |
propagate from branch 'au.asn.ucc.matt.dropbear' (head 0501e6f661b5415eb76f3b312d183c3adfbfb712)
to branch 'au.asn.ucc.matt.dropbear.cli-agent' (head 01038174ec27245b51bd43a66c01ad930880f67b)
--HG--
branch : agent-client
extra : convert_revision : 12b2f59db65e7339d340e95ac67d6d9ddb193c2b
Diffstat (limited to 'libtommath/bn_mp_reduce_is_2k_l.c')
-rw-r--r-- | libtommath/bn_mp_reduce_is_2k_l.c | 40 |
1 files changed, 40 insertions, 0 deletions
diff --git a/libtommath/bn_mp_reduce_is_2k_l.c b/libtommath/bn_mp_reduce_is_2k_l.c new file mode 100644 index 0000000..ceba0ed --- /dev/null +++ b/libtommath/bn_mp_reduce_is_2k_l.c @@ -0,0 +1,40 @@ +#include <tommath.h> +#ifdef BN_MP_REDUCE_IS_2K_L_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 + */ + +/* determines if reduce_2k_l can be used */ +int mp_reduce_is_2k_l(mp_int *a) +{ + int ix, iy; + + if (a->used == 0) { + return MP_NO; + } else if (a->used == 1) { + return MP_YES; + } else if (a->used > 1) { + /* if more than half of the digits are -1 we're sold */ + for (iy = ix = 0; ix < a->used; ix++) { + if (a->dp[ix] == MP_MASK) { + ++iy; + } + } + return (iy >= (a->used/2)) ? MP_YES : MP_NO; + + } + return MP_NO; +} + +#endif |