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_lcm.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_lcm.c')
-rw-r--r-- | libtommath/bn_mp_lcm.c | 56 |
1 files changed, 56 insertions, 0 deletions
diff --git a/libtommath/bn_mp_lcm.c b/libtommath/bn_mp_lcm.c new file mode 100644 index 0000000..8e3a759 --- /dev/null +++ b/libtommath/bn_mp_lcm.c @@ -0,0 +1,56 @@ +#include <tommath.h> +#ifdef BN_MP_LCM_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 + */ + +/* computes least common multiple as |a*b|/(a, b) */ +int mp_lcm (mp_int * a, mp_int * b, mp_int * c) +{ + int res; + mp_int t1, t2; + + + if ((res = mp_init_multi (&t1, &t2, NULL)) != MP_OKAY) { + return res; + } + + /* t1 = get the GCD of the two inputs */ + if ((res = mp_gcd (a, b, &t1)) != MP_OKAY) { + goto LBL_T; + } + + /* divide the smallest by the GCD */ + if (mp_cmp_mag(a, b) == MP_LT) { + /* store quotient in t2 such that t2 * b is the LCM */ + if ((res = mp_div(a, &t1, &t2, NULL)) != MP_OKAY) { + goto LBL_T; + } + res = mp_mul(b, &t2, c); + } else { + /* store quotient in t2 such that t2 * a is the LCM */ + if ((res = mp_div(b, &t1, &t2, NULL)) != MP_OKAY) { + goto LBL_T; + } + res = mp_mul(a, &t2, c); + } + + /* fix the sign to positive */ + c->sign = MP_ZPOS; + +LBL_T: + mp_clear_multi (&t1, &t2, NULL); + return res; +} +#endif |