diff options
Diffstat (limited to 'libtommath/bn_mp_exteuclid.c')
| -rw-r--r-- | libtommath/bn_mp_exteuclid.c | 82 |
1 files changed, 0 insertions, 82 deletions
diff --git a/libtommath/bn_mp_exteuclid.c b/libtommath/bn_mp_exteuclid.c deleted file mode 100644 index e6c4ce2b853..00000000000 --- a/libtommath/bn_mp_exteuclid.c +++ /dev/null @@ -1,82 +0,0 @@ -#include <tommath.h> -#ifdef BN_MP_EXTEUCLID_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://libtom.org - */ - -/* Extended euclidean algorithm of (a, b) produces - a*u1 + b*u2 = u3 - */ -int mp_exteuclid(mp_int *a, mp_int *b, mp_int *U1, mp_int *U2, mp_int *U3) -{ - mp_int u1,u2,u3,v1,v2,v3,t1,t2,t3,q,tmp; - int err; - - if ((err = mp_init_multi(&u1, &u2, &u3, &v1, &v2, &v3, &t1, &t2, &t3, &q, &tmp, NULL)) != MP_OKAY) { - return err; - } - - /* initialize, (u1,u2,u3) = (1,0,a) */ - mp_set(&u1, 1); - if ((err = mp_copy(a, &u3)) != MP_OKAY) { goto _ERR; } - - /* initialize, (v1,v2,v3) = (0,1,b) */ - mp_set(&v2, 1); - if ((err = mp_copy(b, &v3)) != MP_OKAY) { goto _ERR; } - - /* loop while v3 != 0 */ - while (mp_iszero(&v3) == MP_NO) { - /* q = u3/v3 */ - if ((err = mp_div(&u3, &v3, &q, NULL)) != MP_OKAY) { goto _ERR; } - - /* (t1,t2,t3) = (u1,u2,u3) - (v1,v2,v3)q */ - if ((err = mp_mul(&v1, &q, &tmp)) != MP_OKAY) { goto _ERR; } - if ((err = mp_sub(&u1, &tmp, &t1)) != MP_OKAY) { goto _ERR; } - if ((err = mp_mul(&v2, &q, &tmp)) != MP_OKAY) { goto _ERR; } - if ((err = mp_sub(&u2, &tmp, &t2)) != MP_OKAY) { goto _ERR; } - if ((err = mp_mul(&v3, &q, &tmp)) != MP_OKAY) { goto _ERR; } - if ((err = mp_sub(&u3, &tmp, &t3)) != MP_OKAY) { goto _ERR; } - - /* (u1,u2,u3) = (v1,v2,v3) */ - if ((err = mp_copy(&v1, &u1)) != MP_OKAY) { goto _ERR; } - if ((err = mp_copy(&v2, &u2)) != MP_OKAY) { goto _ERR; } - if ((err = mp_copy(&v3, &u3)) != MP_OKAY) { goto _ERR; } - - /* (v1,v2,v3) = (t1,t2,t3) */ - if ((err = mp_copy(&t1, &v1)) != MP_OKAY) { goto _ERR; } - if ((err = mp_copy(&t2, &v2)) != MP_OKAY) { goto _ERR; } - if ((err = mp_copy(&t3, &v3)) != MP_OKAY) { goto _ERR; } - } - - /* make sure U3 >= 0 */ - if (u3.sign == MP_NEG) { - mp_neg(&u1, &u1); - mp_neg(&u2, &u2); - mp_neg(&u3, &u3); - } - - /* copy result out */ - if (U1 != NULL) { mp_exch(U1, &u1); } - if (U2 != NULL) { mp_exch(U2, &u2); } - if (U3 != NULL) { mp_exch(U3, &u3); } - - err = MP_OKAY; -_ERR: mp_clear_multi(&u1, &u2, &u3, &v1, &v2, &v3, &t1, &t2, &t3, &q, &tmp, NULL); - return err; -} -#endif - -/* $Source: /cvs/libtom/libtommath/bn_mp_exteuclid.c,v $ */ -/* $Revision: 1.4 $ */ -/* $Date: 2006/12/28 01:25:13 $ */ |