diff options
Diffstat (limited to 'third_party/heimdal/lib/hcrypto/libtommath/bn_mp_lcm.c')
-rw-r--r-- | third_party/heimdal/lib/hcrypto/libtommath/bn_mp_lcm.c | 44 |
1 files changed, 44 insertions, 0 deletions
diff --git a/third_party/heimdal/lib/hcrypto/libtommath/bn_mp_lcm.c b/third_party/heimdal/lib/hcrypto/libtommath/bn_mp_lcm.c new file mode 100644 index 0000000..c32b269 --- /dev/null +++ b/third_party/heimdal/lib/hcrypto/libtommath/bn_mp_lcm.c @@ -0,0 +1,44 @@ +#include "tommath_private.h" +#ifdef BN_MP_LCM_C +/* LibTomMath, multiple-precision integer library -- Tom St Denis */ +/* SPDX-License-Identifier: Unlicense */ + +/* computes least common multiple as |a*b|/(a, b) */ +mp_err mp_lcm(const mp_int *a, const mp_int *b, mp_int *c) +{ + mp_err err; + mp_int t1, t2; + + + if ((err = mp_init_multi(&t1, &t2, NULL)) != MP_OKAY) { + return err; + } + + /* t1 = get the GCD of the two inputs */ + if ((err = 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 ((err = mp_div(a, &t1, &t2, NULL)) != MP_OKAY) { + goto LBL_T; + } + err = mp_mul(b, &t2, c); + } else { + /* store quotient in t2 such that t2 * a is the LCM */ + if ((err = mp_div(b, &t1, &t2, NULL)) != MP_OKAY) { + goto LBL_T; + } + err = mp_mul(a, &t2, c); + } + + /* fix the sign to positive */ + c->sign = MP_ZPOS; + +LBL_T: + mp_clear_multi(&t1, &t2, NULL); + return err; +} +#endif |