| #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 |