blob: 48b2b63b70190d9732e6cdbe794a9f847451a052 [file] [log] [blame]
 #include #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@gmail.com, http://math.libtomcrypt.com */ /* 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 /* \$Source: /cvs/libtom/libtommath/bn_mp_lcm.c,v \$ */ /* \$Revision: 1.3 \$ */ /* \$Date: 2006/03/31 14:18:44 \$ */