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-rw-r--r--libtommath/bn_mp_exteuclid.c113
1 files changed, 76 insertions, 37 deletions
diff --git a/libtommath/bn_mp_exteuclid.c b/libtommath/bn_mp_exteuclid.c
index 3c9612e..ce0b0a5 100644
--- a/libtommath/bn_mp_exteuclid.c
+++ b/libtommath/bn_mp_exteuclid.c
@@ -1,4 +1,4 @@
-#include <tommath_private.h>
+#include "tommath_private.h"
#ifdef BN_MP_EXTEUCLID_C
/* LibTomMath, multiple-precision integer library -- Tom St Denis
*
@@ -9,18 +9,15 @@
* 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, tstdenis82@gmail.com, http://libtom.org
+ * SPDX-License-Identifier: Unlicense
*/
/* 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)
+int mp_exteuclid(const mp_int *a, const 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;
+ 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) {
@@ -28,48 +25,90 @@ int mp_exteuclid(mp_int *a, mp_int *b, mp_int *U1, mp_int *U2, mp_int *U3)
}
/* initialize, (u1,u2,u3) = (1,0,a) */
- mp_set(&u1, 1);
- if ((err = mp_copy(a, &u3)) != MP_OKAY) { goto LBL_ERR; }
+ mp_set(&u1, 1uL);
+ if ((err = mp_copy(a, &u3)) != MP_OKAY) {
+ goto LBL_ERR;
+ }
/* initialize, (v1,v2,v3) = (0,1,b) */
- mp_set(&v2, 1);
- if ((err = mp_copy(b, &v3)) != MP_OKAY) { goto LBL_ERR; }
+ mp_set(&v2, 1uL);
+ if ((err = mp_copy(b, &v3)) != MP_OKAY) {
+ goto LBL_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 LBL_ERR; }
+ /* q = u3/v3 */
+ if ((err = mp_div(&u3, &v3, &q, NULL)) != MP_OKAY) {
+ goto LBL_ERR;
+ }
- /* (t1,t2,t3) = (u1,u2,u3) - (v1,v2,v3)q */
- if ((err = mp_mul(&v1, &q, &tmp)) != MP_OKAY) { goto LBL_ERR; }
- if ((err = mp_sub(&u1, &tmp, &t1)) != MP_OKAY) { goto LBL_ERR; }
- if ((err = mp_mul(&v2, &q, &tmp)) != MP_OKAY) { goto LBL_ERR; }
- if ((err = mp_sub(&u2, &tmp, &t2)) != MP_OKAY) { goto LBL_ERR; }
- if ((err = mp_mul(&v3, &q, &tmp)) != MP_OKAY) { goto LBL_ERR; }
- if ((err = mp_sub(&u3, &tmp, &t3)) != MP_OKAY) { goto LBL_ERR; }
+ /* (t1,t2,t3) = (u1,u2,u3) - (v1,v2,v3)q */
+ if ((err = mp_mul(&v1, &q, &tmp)) != MP_OKAY) {
+ goto LBL_ERR;
+ }
+ if ((err = mp_sub(&u1, &tmp, &t1)) != MP_OKAY) {
+ goto LBL_ERR;
+ }
+ if ((err = mp_mul(&v2, &q, &tmp)) != MP_OKAY) {
+ goto LBL_ERR;
+ }
+ if ((err = mp_sub(&u2, &tmp, &t2)) != MP_OKAY) {
+ goto LBL_ERR;
+ }
+ if ((err = mp_mul(&v3, &q, &tmp)) != MP_OKAY) {
+ goto LBL_ERR;
+ }
+ if ((err = mp_sub(&u3, &tmp, &t3)) != MP_OKAY) {
+ goto LBL_ERR;
+ }
- /* (u1,u2,u3) = (v1,v2,v3) */
- if ((err = mp_copy(&v1, &u1)) != MP_OKAY) { goto LBL_ERR; }
- if ((err = mp_copy(&v2, &u2)) != MP_OKAY) { goto LBL_ERR; }
- if ((err = mp_copy(&v3, &u3)) != MP_OKAY) { goto LBL_ERR; }
+ /* (u1,u2,u3) = (v1,v2,v3) */
+ if ((err = mp_copy(&v1, &u1)) != MP_OKAY) {
+ goto LBL_ERR;
+ }
+ if ((err = mp_copy(&v2, &u2)) != MP_OKAY) {
+ goto LBL_ERR;
+ }
+ if ((err = mp_copy(&v3, &u3)) != MP_OKAY) {
+ goto LBL_ERR;
+ }
- /* (v1,v2,v3) = (t1,t2,t3) */
- if ((err = mp_copy(&t1, &v1)) != MP_OKAY) { goto LBL_ERR; }
- if ((err = mp_copy(&t2, &v2)) != MP_OKAY) { goto LBL_ERR; }
- if ((err = mp_copy(&t3, &v3)) != MP_OKAY) { goto LBL_ERR; }
+ /* (v1,v2,v3) = (t1,t2,t3) */
+ if ((err = mp_copy(&t1, &v1)) != MP_OKAY) {
+ goto LBL_ERR;
+ }
+ if ((err = mp_copy(&t2, &v2)) != MP_OKAY) {
+ goto LBL_ERR;
+ }
+ if ((err = mp_copy(&t3, &v3)) != MP_OKAY) {
+ goto LBL_ERR;
+ }
}
/* make sure U3 >= 0 */
if (u3.sign == MP_NEG) {
- if ((err = mp_neg(&u1, &u1)) != MP_OKAY) { goto LBL_ERR; }
- if ((err = mp_neg(&u2, &u2)) != MP_OKAY) { goto LBL_ERR; }
- if ((err = mp_neg(&u3, &u3)) != MP_OKAY) { goto LBL_ERR; }
+ if ((err = mp_neg(&u1, &u1)) != MP_OKAY) {
+ goto LBL_ERR;
+ }
+ if ((err = mp_neg(&u2, &u2)) != MP_OKAY) {
+ goto LBL_ERR;
+ }
+ if ((err = mp_neg(&u3, &u3)) != MP_OKAY) {
+ goto LBL_ERR;
+ }
}
/* copy result out */
- if (U1 != NULL) { mp_exch(U1, &u1); }
- if (U2 != NULL) { mp_exch(U2, &u2); }
- if (U3 != NULL) { mp_exch(U3, &u3); }
+ if (U1 != NULL) {
+ mp_exch(U1, &u1);
+ }
+ if (U2 != NULL) {
+ mp_exch(U2, &u2);
+ }
+ if (U3 != NULL) {
+ mp_exch(U3, &u3);
+ }
err = MP_OKAY;
LBL_ERR:
@@ -78,6 +117,6 @@ LBL_ERR:
}
#endif
-/* ref: $Format:%D$ */
-/* git commit: $Format:%H$ */
-/* commit time: $Format:%ai$ */
+/* ref: HEAD -> master, tag: v1.1.0 */
+/* git commit: 08549ad6bc8b0cede0b357a9c341c5c6473a9c55 */
+/* commit time: 2019-01-28 20:32:32 +0100 */