5 * Elliptic Curve Arithmetic Functions
7 * Copyright (C) Lenka Fibikova 2000
17 #include <openssl/bn.h>
27 ret=(EC_POINT *)malloc(sizeof(EC_POINT));
28 if (ret == NULL) return NULL;
34 if (ret->X == NULL || ret->Y == NULL || ret->Z == NULL)
36 if (ret->X != NULL) BN_free(ret->X);
37 if (ret->Y != NULL) BN_free(ret->Y);
38 if (ret->Z != NULL) BN_free(ret->Z);
45 void ECP_clear_free(EC_POINT *P)
47 if (P == NULL) return;
50 if (P->X != NULL) BN_clear_free(P->X);
51 if (P->Y != NULL) BN_clear_free(P->Y);
52 if (P->Z != NULL) BN_clear_free(P->Z);
56 void ECP_clear_free_precompute(ECP_PRECOMPUTE *prec)
61 if (prec == NULL) return;
65 max <<= (prec->r - 1);
67 for (i = 0; i < max; i++)
69 if (prec->Pi[i] != NULL) ECP_clear_free(prec->Pi[i]);
75 int ECP_is_on_ec(EC_POINT *P, EC *E, BN_CTX *ctx)
77 BIGNUM *n0, *n1, *n2, *p;
81 assert(P->X != NULL && P->Y != NULL && P->Z != NULL);
84 assert(E->A != NULL && E->B != NULL && E->p != NULL);
88 assert(!P->is_in_mont);
90 if (ECP_is_infty(P)) return 1;
92 n0 = ctx->bn[ctx->tos];
93 n1 = ctx->bn[ctx->tos + 1];
94 n2 = ctx->bn[ctx->tos + 2];
100 Pnorm = (ECP_is_norm(P));
104 if (!BN_mod_mul(n0, P->Z, P->Z, p, ctx)) goto err;
105 if (!BN_mod_mul(n1, n0, n0, p, ctx)) goto err;
106 if (!BN_mod_mul(n2, n0, n1, p, ctx)) goto err;
109 if (!BN_mod_mul(n0, P->X, P->X, p, ctx)) goto err;
110 if (!BN_mod_mul(n0, n0, P->X, p, ctx)) goto err;
114 if (!BN_mod_mul(n1, P->X, E->A, p, ctx)) goto err;
118 if (!BN_mod_mul(n1, n1, P->X, p, ctx)) goto err;
119 if (!BN_mod_mul(n1, n1, E->A, p, ctx)) goto err;
121 if (!BN_mod_add(n0, n0, n1, p, ctx)) goto err;
125 if (!BN_mod_add(n0, n0, E->B, p, ctx)) goto err;
129 if (!BN_mod_mul(n2, n2, E->B, p, ctx)) goto err;
130 if (!BN_mod_add(n0, n0, n2, p, ctx)) goto err;
133 if (!BN_mod_mul(n1, P->Y, P->Y, p, ctx)) goto err;
150 EC_POINT *ECP_generate(BIGNUM *x, BIGNUM *z,EC *E, BN_CTX *ctx)
151 /* x == NULL || z = 0 -> point of infinity */
152 /* z == NULL || z = 1 -> normalized */
156 int Pnorm, Pinfty, X0, A0;
159 assert(E->A != NULL && E->B != NULL && E->p != NULL && E->h != NULL);
163 Pinfty = (x == NULL);
167 Pnorm = BN_is_one(z);
168 Pinfty = (Pinfty || BN_is_zero(z));
173 if ((ret = ECP_new()) == NULL) return NULL;
174 if (!BN_zero(ret->Z))
183 A0 = BN_is_zero(E->A);
185 if ((ret = ECP_new()) == NULL) return NULL;
189 n0 = ctx->bn[ctx->tos];
190 n1 = ctx->bn[ctx->tos + 1];
191 if (!BN_zero(n0)) return NULL;
192 if (!BN_zero(n1)) return NULL;
198 if (!BN_mod_sqr(n0, x, E->p, ctx)) goto err;
199 if (!BN_mod_mul(n0, n0, x, E->p, ctx)) goto err; /* x^3 */
204 if (!BN_mod_mul(n1, E->A, x, E->p, ctx)) goto err; /* Ax */
205 if (!BN_mod_add(n0, n0, n1, E->p, ctx)) goto err; /* x^3 + Ax */
208 if (!BN_is_zero(E->B))
209 if (!BN_mod_add(n0, n0, E->B, E->p, ctx)) goto err; /* x^3 + Ax +B */
211 if (!BN_mod_sqrt(ret->Y, n0, E->p, ctx)) goto err;
212 if (BN_copy(ret->X, x) == NULL) goto err;
216 if (!BN_one(ret->Z)) goto err;
220 if (BN_copy(ret->Z, z) == NULL) goto err;
221 if (!BN_mod_sqr(n0, z, E->p, ctx)) goto err;
222 if (!BN_mod_mul(ret->X, ret->X, n0, E->p, ctx)) goto err;
223 if (!BN_mod_mul(n0, n0, z, E->p, ctx)) goto err;
224 if (!BN_mod_mul(ret->Y, ret->Y, n0, E->p, ctx)) goto err;
228 if (!ECP_is_on_ec(ret, E, ctx)) goto err;
235 if (ret != NULL) ECP_clear_free(ret);
240 int ECP_ecp2bin(EC_POINT *P, unsigned char *to, int form)
241 /* form = 1 ... compressed
248 assert (P->X != NULL && P->Y != NULL && P->Z != NULL);
249 assert (!P->is_in_mont);
250 assert (ECP_is_norm(P) || ECP_is_infty(P));
252 assert (form > 0 && form < 4);
254 if (BN_is_zero(P->Z))
260 bx = BN_num_bytes(P->X);
261 if (form == 1 ) bytes = bx + 1;
264 by = BN_num_bytes(P->Y);
265 bytes = (bx > by ? bx : by);
266 bytes = bytes * 2 + 1;
268 memset(to, 0, bytes);
272 case 1: to[0] = 2; break;
273 case 2: to[0] = 4; break;
274 case 3: to[0] = 6; break;
276 if (form != 2) to[0] += BN_is_bit_set(P->Y, 0);
279 if ((BN_bn2bin(P->X, to + 1)) != bx) return 0;
282 if ((BN_bn2bin(P->Y, to + bx + 1)) != by) return 0;
288 int ECP_bin2ecp(unsigned char *from, int len, EC_POINT *P, EC *E, BN_CTX *ctx)
295 assert (E->A != NULL && E->B != NULL && E->p != NULL);
296 assert (!E->is_in_mont);
298 assert (ctx != NULL);
299 assert (from != NULL);
301 assert (P->X != NULL && P->Y != NULL && P->Z != NULL);
303 if (len == 1 && from[0] != 0) return 0;
305 if (len == 0 || len == 1)
307 if (!BN_zero(P->Z)) return 0;
316 if ((x = BN_new()) == NULL) return 0;
317 if (BN_bin2bn(from + 1, len - 1, x) == NULL) return 0;
319 pp = ECP_generate(x, NULL, E, ctx);
321 if (pp == NULL) return 0;
326 if (BN_is_bit_set(P->Y, 0) != y)
327 if (!BN_sub(P->Y, E->p, P->Y)) return 0;
334 if (BN_bin2bn(from + 1, y, P->X) == NULL) return 0;
335 if (BN_bin2bn(from + y + 1, y, P->Y) == NULL) return 0;
336 if (!BN_set_word(P->Z, 1)) return 0;
344 if (!ECP_is_on_ec(P, E, ctx)) return 0;
348 int ECP_normalize(EC_POINT *P, EC *E, BN_CTX *ctx)
353 assert (P->X != NULL && P->Y != NULL && P->Z != NULL);
356 assert (E->A != NULL && E->B != NULL && E->p != NULL);
358 assert (ctx != NULL);
360 if (ECP_is_norm(P)) return 1;
361 if (ECP_is_infty(P)) return 0;
363 if ((zm = BN_mod_inverse(P->Z, P->Z, E->p, ctx)) == NULL) return 0;
365 assert(!P->is_in_mont);
368 z = ctx->bn[ctx->tos];
371 if (!BN_mod_mul(z, zm, zm, E->p, ctx)) goto err;
372 if (!BN_mod_mul(P->X, P->X, z, E->p, ctx)) goto err;
374 if (!BN_mod_mul(z, z, zm, E->p, ctx)) goto err;
375 if (!BN_mod_mul(P->Y, P->Y, z, E->p, ctx)) goto err;
377 if (!BN_one(P->Z)) goto err;
379 if (zm != NULL) BN_clear_free(zm);
385 if (zm != NULL) BN_clear_free(zm);
390 int ECP_copy(EC_POINT *R, EC_POINT *P)
393 assert(P->X != NULL && P->Y != NULL && P->Z != NULL);
396 assert(R->X != NULL && R->Y != NULL && R->Z != NULL);
398 if (BN_copy(R->X, P->X) == NULL) return 0;
399 if (BN_copy(R->Y, P->Y) == NULL) return 0;
400 if (BN_copy(R->Z, P->Z) == NULL) return 0;
401 R->is_in_mont = P->is_in_mont;
406 EC_POINT *ECP_dup(EC_POINT *P)
411 if (ret == NULL) return NULL;
413 if (!ECP_copy(ret, P))
423 EC_POINT *ECP_minus(EC_POINT *P, BIGNUM *p) /* mont || non-mont */
428 assert(P->X != NULL && P->Y != NULL && P->Z != NULL);
432 assert(BN_cmp(P->Y, p) < 0);
435 if (ret == NULL) return NULL;
437 if (BN_is_zero(ret->Y)) return ret;
439 if (!BN_sub(ret->Y, p, ret->Y))
450 int ECP_cmp(EC_POINT *P, EC_POINT *Q, BIGNUM *p, BN_CTX *ctx)
458 BIGNUM *n0, *n1, *n2, *n3, *n4;
462 assert(P->X != NULL && P->Y != NULL && P->Z != NULL);
465 assert(Q->X != NULL && Q->Y != NULL && Q->Z != NULL);
470 assert(!P->is_in_mont);
471 assert(!Q->is_in_mont);
473 if (ECP_is_infty(P) && ECP_is_infty(Q)) return 0;
474 if (ECP_is_infty(P) || ECP_is_infty(Q)) return 1;
477 Pnorm = (ECP_is_norm(P));
478 Qnorm = (ECP_is_norm(Q));
480 n0 = ctx->bn[ctx->tos];
481 n1 = ctx->bn[ctx->tos + 1];
482 n2 = ctx->bn[ctx->tos + 2];
483 n3 = ctx->bn[ctx->tos + 3];
484 n4 = ctx->bn[ctx->tos + 4];
489 if (BN_copy(n1, P->X) == NULL) goto err; /* L1 = x_p */
490 if (BN_copy(n2, P->Y) == NULL) goto err; /* L2 = y_p */
494 if (!BN_sqr(n0, Q->Z, ctx)) goto err;
495 if (!BN_mod_mul(n1, P->X, n0, p, ctx)) goto err; /* L1 = x_p * z_q^2 */
497 if (!BN_mod_mul(n0, n0, Q->Z, p, ctx)) goto err;
498 if (!BN_mod_mul(n2, P->Y, n0, p, ctx)) goto err; /* L2 = y_p * z_q^3 */
503 if (BN_copy(n3, Q->X) == NULL) goto err; /* L3 = x_q */
504 if (BN_copy(n4, Q->Y) == NULL) goto err; /* L4 = y_q */
508 if (!BN_sqr(n0, P->Z, ctx)) goto err;
509 if (!BN_mod_mul(n3, Q->X, n0, p, ctx)) goto err; /* L3 = x_q * z_p^2 */
511 if (!BN_mod_mul(n0, n0, P->Z, p, ctx)) goto err;
512 if (!BN_mod_mul(n4, Q->Y, n0, p, ctx)) goto err; /* L4 = y_q * z_p^3 */
515 if (!BN_mod_sub(n0, n1, n3, p, ctx)) goto err; /* L5 = L1 - L3 */
523 if (!BN_mod_sub(n0, n2, n4, p, ctx)) goto err; /* L6 = L2 - L4 */
539 int ECP_double(EC_POINT *R, EC_POINT *P, EC *E, BN_CTX *ctx)
542 BIGNUM *n0, *n1, *n2, *n3, *p;
546 assert(P->X != NULL && P->Y != NULL && P->Z != NULL);
549 assert(R->X != NULL && R->Y != NULL && R->Z != NULL);
552 assert(E->A != NULL && E->B != NULL && E->p != NULL && E->h != NULL);
556 assert(!P->is_in_mont);
560 if (!BN_zero(R->Z)) return 0;
564 Pnorm = (ECP_is_norm(P));
565 A0 = (BN_is_zero(E->A));
567 n0 = ctx->bn[ctx->tos];
568 n1 = ctx->bn[ctx->tos + 1];
569 n2 = ctx->bn[ctx->tos + 2];
570 n3 = ctx->bn[ctx->tos + 3];
578 if (!BN_mod_sqr(n1, P->X, p, ctx)) goto err;
579 if (!BN_mul_word(n1, 3)) goto err;
580 if (!A0) /* if A = 0: L1 = 3 * x^2 + a * z^4 = 3 * x ^2 */
581 if (!BN_mod_add(n1, n1, E->A, p, ctx)) goto err; /* L1 = 3 * x^2 + a * z^4 = 3 * x^2 + a */
585 if (!BN_mod_sqr(n0, P->Z, p, ctx)) goto err;
586 if (!BN_mod_mul(n0, n0, n0, p, ctx)) goto err;
587 if (!BN_mod_mul(n0, n0, E->A, p, ctx)) goto err;
588 if (!BN_mod_sqr(n1, P->X, p, ctx)) goto err;
589 if (!BN_mul_word(n1, 3)) goto err;
590 if (!BN_mod_add(n1, n1, n0, p, ctx)) goto err; /* L1 = 3 * x^2 + a * z^4 */
596 if (BN_copy(n0, P->Y) == NULL) goto err;
600 if (!BN_mod_mul(n0, P->Y, P->Z, p, ctx)) goto err;
602 if (!BN_lshift1(n0, n0)) goto err;
603 if (!BN_smod(R->Z, n0, p, ctx)) goto err; /* Z = 2 * y * z */
606 if (!BN_mod_sqr(n3, P->Y, p, ctx)) goto err;
607 if (!BN_mod_mul(n2, P->X, n3, p, ctx)) goto err;
608 if (!BN_lshift(n2, n2, 2)) goto err;
609 if (!BN_smod(n2, n2, p, ctx)) goto err; /* L2 = 4 * x * y^2 */
612 if (!BN_lshift1(n0, n2)) goto err;
613 if (!BN_mod_sqr(R->X, n1, p, ctx)) goto err;
614 if (!BN_mod_sub(R->X, R->X, n0, p, ctx)) goto err; /* X = L1^2 - 2 * L2 */
617 if (!BN_mod_sqr(n0, n3, p, ctx)) goto err;
618 if (!BN_lshift(n3, n0, 3)) goto err;
619 if (!BN_smod(n3, n3, p, ctx)) goto err; /* L3 = 8 * y^4 */
622 if (!BN_mod_sub(n0, n2, R->X, p, ctx)) goto err;
623 if (!BN_mod_mul(n0, n1, n0, p, ctx)) goto err;
624 if (!BN_mod_sub(R->Y, n0, n3, p, ctx)) goto err; /* Y = L1 * (L2 - X) - L3 */
628 if (!ECP_is_on_ec(R, E, ctx)) return 0;
639 int ECP_add(EC_POINT *R, EC_POINT *P, EC_POINT *Q, EC *E, BN_CTX *ctx)
640 /* R <- P + Q (on E) */
642 BIGNUM *n0, *n1, *n2, *n3, *n4, *n5, *n6, *p;
646 assert(P->X != NULL && P->Y != NULL && P->Z != NULL);
649 assert(Q->X != NULL && Q->Y != NULL && Q->Z != NULL);
652 assert(R->X != NULL && R->Y != NULL && R->Z != NULL);
655 assert(E->A != NULL && E->B != NULL && E->p != NULL && E->h != NULL);
656 assert(!BN_is_zero(E->h));;
660 assert(!P->is_in_mont);
661 assert(!Q->is_in_mont);
663 if (P == Q) return ECP_double(R, P, E, ctx);
665 if (ECP_is_infty(P)) return ECP_copy(R, Q);
666 if (ECP_is_infty(Q)) return ECP_copy(R, P);
668 Pnorm = (ECP_is_norm(P));
669 Qnorm = (ECP_is_norm(Q));
671 n0 = ctx->bn[ctx->tos];
672 n1 = ctx->bn[ctx->tos + 1];
673 n2 = ctx->bn[ctx->tos + 2];
674 n3 = ctx->bn[ctx->tos + 3];
675 n4 = ctx->bn[ctx->tos + 4];
676 n5 = ctx->bn[ctx->tos + 5];
677 n6 = ctx->bn[ctx->tos + 6];
684 if (BN_copy(n1, P->X) == NULL) goto err; /* L1 = x_p */
685 if (BN_copy(n2, P->Y) == NULL) goto err; /* L2 = y_p */
689 if (!BN_sqr(n0, Q->Z, ctx)) goto err;
690 if (!BN_mod_mul(n1, P->X, n0, p, ctx)) goto err; /* L1 = x_p * z_q^2 */
692 if (!BN_mod_mul(n0, n0, Q->Z, p, ctx)) goto err;
693 if (!BN_mod_mul(n2, P->Y, n0, p, ctx)) goto err; /* L2 = y_p * z_q^3 */
699 if (BN_copy(n3, Q->X) == NULL) goto err; /* L3 = x_q */
700 if (BN_copy(n4, Q->Y) == NULL) goto err; /* L4 = y_q */
704 if (!BN_sqr(n0, P->Z, ctx)) goto err;
705 if (!BN_mod_mul(n3, Q->X, n0, p, ctx)) goto err; /* L3 = x_q * z_p^2 */
707 if (!BN_mod_mul(n0, n0, P->Z, p, ctx)) goto err;
708 if (!BN_mod_mul(n4, Q->Y, n0, p, ctx)) goto err; /* L4 = y_q * z_p^3 */
712 if (!BN_mod_sub(n5, n1, n3, p, ctx)) goto err; /* L5 = L1 - L3 */
713 if (!BN_mod_sub(n6, n2, n4, p, ctx)) goto err; /* L6 = L2 - L4 */
718 if (BN_is_zero(n6)) /* P = Q => P + Q = 2P */
721 return ECP_double(R, P, E, ctx);
723 else /* P = -Q => P + Q = \infty */
726 if (!BN_zero(R->Z)) return 0;
732 if (!BN_mod_add(n1, n1, n3, p, ctx)) goto err; /* L7 = L1 + L3 */
733 if (!BN_mod_add(n2, n2, n4, p, ctx)) goto err; /* L8 = L2 + L4 */
738 if (BN_copy(n0, Q->Z) == NULL) goto err;
742 if (!BN_mod_mul(n0, P->Z, Q->Z, p, ctx)) goto err;
744 if (!BN_mod_mul(R->Z, n0, n5, p, ctx)) goto err; /* Z = z_p * z_q * L_5 */
747 if (!BN_mod_sqr(n0, n6, p, ctx)) goto err;
748 if (!BN_mod_sqr(n4, n5, p, ctx)) goto err;
749 if (!BN_mod_mul(n3, n1, n4, p, ctx)) goto err;
750 if (!BN_mod_sub(R->X, n0, n3, p, ctx)) goto err; /* X = L6^2 - L5^2 * L7 */
753 if (!BN_lshift1(n0, R->X)) goto err;
754 if (!BN_mod_sub(n0, n3, n0, p, ctx)) goto err; /* L9 = L5^2 * L7 - 2X */
757 if (!BN_mod_mul(n0, n0, n6, p, ctx)) goto err;
758 if (!BN_mod_mul(n5, n4, n5, p, ctx)) goto err;
759 if (!BN_mod_mul(n1, n2, n5, p, ctx)) goto err;
760 if (!BN_mod_sub(n0, n0, n1, p, ctx)) goto err;
761 if (!BN_mod_mul(R->Y, n0, E->h, p, ctx)) goto err; /* Y = (L6 * L9 - L8 * L5^3) / 2 */
766 if (!ECP_is_on_ec(R, E, ctx)) return 0;
778 ECP_PRECOMPUTE *ECP_precompute(int r, EC_POINT *P, EC *E, BN_CTX *ctx)
785 assert(!P->is_in_mont);
786 assert(!E->is_in_mont);
788 ret=(ECP_PRECOMPUTE *)malloc(sizeof(ECP_PRECOMPUTE));
789 if (ret == NULL) return NULL;
796 ret->Pi=(EC_POINT **)malloc(sizeof(EC_POINT *) * max);
797 if (ret->Pi == NULL) goto err;
801 if ((P2 = ECP_new()) == NULL) goto err;
802 if (!ECP_double(P2, P, E, ctx)) goto err;
805 if((ret->Pi[0] = ECP_dup(P)) == NULL) goto err;
808 /* P_i = P_(i-1) + P2 */
809 for (i = 1; i < max; i++)
811 if ((ret->Pi[i] = ECP_new()) == NULL) goto err;
813 if (!ECP_add(ret->Pi[i], P2, ret->Pi[i - 1], E, ctx)) goto err;
823 ECP_clear_free_precompute(ret);
827 int ECP_multiply(EC_POINT *R, BIGNUM *k, ECP_PRECOMPUTE *prec, EC *E, BN_CTX *ctx)
834 assert(R->X != NULL && R->Y != NULL && R->Z != NULL);
837 assert(E->A != NULL && E->B != NULL && E->p != NULL && E->h != NULL);
843 assert(prec != NULL);
845 assert(!E->is_in_mont);
849 if (!BN_zero(R->Z)) return 0;
860 if (!BN_zero(R->Z)) return 0;
865 if (!BN_is_bit_set(k, j))
867 if (!ECP_double(R, R, E, ctx)) return 0;
873 if (nextw < -1) nextw = -1;
875 while(!BN_is_bit_set(k, t))
880 if (!ECP_double(R, R, E, ctx)) return 0;
890 if (BN_is_bit_set(k, j)) h++;
891 if (!ECP_double(R, R, E, ctx)) return 0;
893 if (!ECP_double(R, R, E, ctx)) return 0;
897 if (!ECP_add(R, R, prec->Pi[h], E, ctx)) return 0;
899 for (; j > nextw; j--)
901 if (!ECP_double(R, R, E, ctx)) return 0;
914 int ECP_to_montgomery(EC_POINT *P, BN_MONTGOMERY *mont, BN_CTX *ctx)
918 assert(P->X != NULL && P->Y != NULL && P->Z != NULL);
920 assert(mont != NULL);
921 assert(mont->p != NULL);
925 if (P->is_in_mont) return 1;
927 if (!BN_lshift(P->X, P->X, mont->R_num_bits)) return 0;
928 if (!BN_mod(P->X, P->X, mont->p, ctx)) return 0;
930 if (!BN_lshift(P->Y, P->Y, mont->R_num_bits)) return 0;
931 if (!BN_mod(P->Y, P->Y, mont->p, ctx)) return 0;
933 if (!BN_lshift(P->Z, P->Z, mont->R_num_bits)) return 0;
934 if (!BN_mod(P->Z, P->Z, mont->p, ctx)) return 0;
941 int ECP_from_montgomery(EC_POINT *P, BN_MONTGOMERY *mont, BN_CTX *ctx)
945 assert(P->X != NULL && P->Y != NULL && P->Z != NULL);
947 assert(mont != NULL);
948 assert(mont->p != NULL);
952 if (!P->is_in_mont) return 1;
954 if (!BN_mont_red(P->X, mont, ctx)) return 0;
955 if (!BN_mont_red(P->Y, mont, ctx)) return 0;
956 if (!BN_mont_red(P->Z, mont, ctx)) return 0;
962 int ECP_mont_cmp(EC_POINT *P, EC_POINT *Q, BN_MONTGOMERY *mont, BN_CTX *ctx)
970 BIGNUM *n0, *n1, *n2, *n3, *n4, *n5, *p;
973 assert(P->X != NULL && P->Y != NULL && P->Z != NULL);
976 assert(Q->X != NULL && Q->Y != NULL && Q->Z != NULL);
978 assert(mont != NULL);
979 assert(mont->p != NULL);
984 if (!ECP_to_montgomery(P, mont, ctx)) return 0;
987 if (!ECP_to_montgomery(Q, mont, ctx)) return 0;
990 if (ECP_is_infty(P) && ECP_is_infty(Q)) return 0;
991 if (ECP_is_infty(P) || ECP_is_infty(Q)) return 1;
994 n0 = ctx->bn[ctx->tos];
995 n1 = ctx->bn[ctx->tos + 1];
996 n2 = ctx->bn[ctx->tos + 2];
997 n3 = ctx->bn[ctx->tos + 3];
998 n4 = ctx->bn[ctx->tos + 4];
999 n5 = ctx->bn[ctx->tos + 5];
1005 if (!BN_mont_mod_mul(n5, Q->Z, Q->Z, mont, ctx)) goto err;
1006 if (!BN_mont_mod_mul(n1, P->X, n5, mont, ctx)) goto err; /* L1 = x_p * z_q^2 */
1008 if (!BN_mont_mod_mul(n0, n5, Q->Z, mont, ctx)) goto err;
1009 if (!BN_mont_mod_mul(n2, P->Y, n0, mont, ctx)) goto err; /* L2 = y_p * z_q^3 */
1011 if (!BN_mont_mod_mul(n5, P->Z, P->Z, mont, ctx)) goto err;
1012 if (!BN_mont_mod_mul(n3, Q->X, n5, mont, ctx)) goto err; /* L3 = x_q * z_p^2 */
1014 if (!BN_mont_mod_mul(n0, n5, P->Z, mont, ctx)) goto err;
1015 if (!BN_mont_mod_mul(n4, Q->Y, n0, mont, ctx)) goto err; /* L4 = y_q * z_p^3 */
1018 if (!BN_mod_sub_quick(n0, n1, n3, p)) goto err; /* L5 = L1 - L3 */
1020 if (!BN_is_zero(n0))
1026 if (!BN_mod_sub_quick(n0, n2, n4, p)) goto err; /* L6 = L2 - L4 */
1028 if (!BN_is_zero(n0))
1043 int ECP_mont_double(EC_POINT *R, EC_POINT *P, EC *E, BN_MONTGOMERY *mont, BN_CTX *ctx)
1044 /* R <- 2P (on E) */
1046 BIGNUM *n0, *n1, *n2, *n3, *p;
1049 assert(P->X != NULL && P->Y != NULL && P->Z != NULL);
1052 assert(R->X != NULL && R->Y != NULL && R->Z != NULL);
1055 assert(E->A != NULL && E->B != NULL && E->p != NULL && E->h != NULL);
1057 assert(ctx != NULL);
1060 if (!ECP_to_montgomery(P, mont, ctx)) return 0;
1063 if (!EC_to_montgomery(E, mont, ctx)) return 0;
1067 if (ECP_is_infty(P))
1069 if (!BN_zero(R->Z)) return 0;
1074 n0 = ctx->bn[ctx->tos];
1075 n1 = ctx->bn[ctx->tos + 1];
1076 n2 = ctx->bn[ctx->tos + 2];
1077 n3 = ctx->bn[ctx->tos + 3];
1084 if (!BN_mont_mod_mul(n0, P->Z, P->Z, mont, ctx)) goto err;
1085 if (!BN_mont_mod_mul(n2, n0, n0, mont, ctx)) goto err;
1086 if (!BN_mont_mod_mul(n0, n2, E->A, mont, ctx)) goto err;
1087 if (!BN_mont_mod_mul(n1, P->X, P->X, mont, ctx)) goto err;
1088 if (!BN_mod_lshift1_quick(n2, n1, p)) goto err;
1089 if (!BN_mod_add_quick(n1, n1, n2, p)) goto err;
1090 if (!BN_mod_add_quick(n1, n1, n0, p)) goto err; /* L1 = 3 * x^2 + a * z^4 */
1093 if (!BN_mont_mod_mul(n0, P->Y, P->Z, mont, ctx)) goto err;
1094 if (!BN_mod_lshift1_quick(R->Z, n0, p)) goto err; /* Z = 2 * y * z */
1097 if (!BN_mont_mod_mul(n3, P->Y, P->Y, mont, ctx)) goto err;
1098 if (!BN_mont_mod_mul(n2, P->X, n3, mont, ctx)) goto err;
1099 if (!BN_mod_lshift_quick(n2, n2, 2, p)) goto err; /* L2 = 4 * x * y^2 */
1102 if (!BN_mod_lshift1_quick(n0, n2, p)) goto err;
1103 if (!BN_mont_mod_mul(R->X, n1, n1, mont, ctx)) goto err;
1104 if (!BN_mod_sub_quick(R->X, R->X, n0, p)) goto err; /* X = L1^2 - 2 * L2 */
1107 if (!BN_mont_mod_mul(n0, n3, n3, mont, ctx)) goto err;
1108 if (!BN_mod_lshift_quick(n3, n0, 3, p)) goto err; /* L3 = 8 * y^4 */
1112 if (!BN_mod_sub_quick(n2, n2, R->X, p)) goto err;
1113 if (!BN_mont_mod_mul(n0, n1, n2, mont, ctx)) goto err;
1114 if (!BN_mod_sub_quick(R->Y, n0, n3, p)) goto err; /* Y = L1 * (L2 - X) - L3 */
1125 int ECP_mont_add(EC_POINT *R, EC_POINT *P, EC_POINT *Q, EC *E, BN_MONTGOMERY *mont, BN_CTX *ctx)
1126 /* R <- P + Q (on E) */
1128 BIGNUM *n0, *n1, *n2, *n3, *n4, *n5, *n6, *p;
1131 assert(P->X != NULL && P->Y != NULL && P->Z != NULL);
1134 assert(Q->X != NULL && Q->Y != NULL && Q->Z != NULL);
1137 assert(R->X != NULL && R->Y != NULL && R->Z != NULL);
1140 assert(E->A != NULL && E->B != NULL && E->p != NULL && E->h != NULL);
1141 assert(!BN_is_zero(E->h));;
1143 assert(ctx != NULL);
1146 if (!ECP_to_montgomery(Q, mont, ctx)) return 0;
1149 if (!ECP_to_montgomery(P, mont, ctx)) return 0;
1152 if (!EC_to_montgomery(E, mont, ctx)) return 0;
1154 if (P == Q) return ECP_mont_double(R, P, E, mont, ctx);
1156 if (ECP_is_infty(P)) return ECP_copy(R, Q);
1157 if (ECP_is_infty(Q)) return ECP_copy(R, P);
1160 n0 = ctx->bn[ctx->tos];
1161 n1 = ctx->bn[ctx->tos + 1];
1162 n2 = ctx->bn[ctx->tos + 2];
1163 n3 = ctx->bn[ctx->tos + 3];
1164 n4 = ctx->bn[ctx->tos + 4];
1165 n5 = ctx->bn[ctx->tos + 5];
1166 n6 = ctx->bn[ctx->tos + 6];
1175 if (!BN_mont_mod_mul(n6, Q->Z, Q->Z, mont, ctx)) goto err;
1176 if (!BN_mont_mod_mul(n1, P->X, n6, mont, ctx)) goto err; /* L1 = x_p * z_q^2 */
1178 if (!BN_mont_mod_mul(n0, n6, Q->Z, mont, ctx)) goto err;
1179 if (!BN_mont_mod_mul(n2, P->Y, n0, mont, ctx)) goto err; /* L2 = y_p * z_q^3 */
1183 if (!BN_mont_mod_mul(n6, P->Z, P->Z, mont, ctx)) goto err;
1184 if (!BN_mont_mod_mul(n3, Q->X, n6, mont, ctx)) goto err; /* L3 = x_q * z_p^2 */
1186 if (!BN_mont_mod_mul(n0, n6, P->Z, mont, ctx)) goto err;
1187 if (!BN_mont_mod_mul(n4, Q->Y, n0, mont, ctx)) goto err; /* L4 = y_q * z_p^3 */
1191 if (!BN_mod_sub_quick(n5, n1, n3, p)) goto err; /* L5 = L1 - L3 */
1192 if (!BN_mod_sub_quick(n6, n2, n4, p)) goto err; /*L6 = L2 - L4 */
1198 if (BN_is_zero(n6)) /* P = Q => P + Q = 2P */
1201 return ECP_mont_double(R, P, E, mont, ctx);
1203 else /* P = -Q => P + Q = \infty */
1206 if (!BN_zero(R->Z)) return 0;
1212 if (!BN_mod_add_quick(n1, n1, n3, p)) goto err; /* L7 = L1 + L3 */
1213 if (!BN_mod_add_quick(n2, n2, n4, p)) goto err; /* L8 = L2 + L4 */
1217 if (!BN_mont_mod_mul(n0, P->Z, Q->Z, mont, ctx)) goto err;
1218 if (!BN_mont_mod_mul(R->Z, n0, n5, mont, ctx)) goto err; /* Z = z_p * z_q * L_5 */
1222 if (!BN_mont_mod_mul(n0, n6, n6, mont, ctx)) goto err;
1223 if (!BN_mont_mod_mul(n4, n5, n5, mont, ctx)) goto err;
1224 if (!BN_mont_mod_mul(n3, n1, n4, mont, ctx)) goto err;
1225 if (!BN_mod_sub_quick(R->X, n0, n3, p)) goto err; /* X = L6^2 - L5^2 * L7 */
1229 if (!BN_mod_lshift1_quick(n0, R->X, p)) goto err;
1230 if (!BN_mod_sub_quick(n3, n3, n0, p)) goto err; /* L9 = L5^2 * L7 - 2X */
1234 if (!BN_mont_mod_mul(n0, n3, n6, mont, ctx)) goto err;
1235 if (!BN_mont_mod_mul(n6, n4, n5, mont, ctx)) goto err;
1236 if (!BN_mont_mod_mul(n1, n2, n6, mont, ctx)) goto err;
1237 if (!BN_mod_sub_quick(n0, n0, n1, p)) goto err;
1238 if (!BN_mont_mod_mul(R->Y, n0, E->h, mont, ctx)) goto err; /* Y = (L6 * L9 - L8 * L5^3) / 2 */
1250 ECP_PRECOMPUTE *ECP_mont_precompute(int r, EC_POINT *P, EC *E, BN_MONTGOMERY *mont, BN_CTX *ctx)
1252 ECP_PRECOMPUTE *ret;
1257 assert(r < sizeof(unsigned int) * 8 - 1);
1259 assert(mont != NULL);
1260 assert(mont->p != NULL);
1263 if (!ECP_to_montgomery(P, mont, ctx)) return 0;
1266 if (!EC_to_montgomery(E, mont, ctx)) return 0;
1268 ret=(ECP_PRECOMPUTE *)malloc(sizeof(ECP_PRECOMPUTE));
1269 if (ret == NULL) return NULL;
1276 ret->Pi=(EC_POINT **)malloc(sizeof(EC_POINT *) * max);
1277 if (ret->Pi == NULL) goto err;
1281 if ((P2 = ECP_new()) == NULL) goto err;
1282 if (!ECP_mont_double(P2, P, E, mont, ctx)) goto err;
1285 if((ret->Pi[0] = ECP_dup(P)) == NULL) goto err;
1288 /* P_i = P_(i-1) + P2 */
1289 for (i = 1; i < max; i++)
1291 if ((ret->Pi[i] = ECP_new()) == NULL) goto err;
1292 if (!ECP_mont_add(ret->Pi[i], P2, ret->Pi[i - 1], E, mont, ctx)) goto err;
1302 ECP_clear_free_precompute(ret);
1306 int ECP_mont_multiply(EC_POINT *R, BIGNUM *k, ECP_PRECOMPUTE *prec, EC *E, BN_MONTGOMERY *mont, BN_CTX *ctx)
1307 /* R = [k]P P = prec->Pi[0]*/
1313 assert(R->X != NULL && R->Y != NULL && R->Z != NULL);
1316 assert(E->A != NULL && E->B != NULL && E->p != NULL && E->h != NULL);
1321 assert(ctx != NULL);
1322 assert(prec != NULL);
1324 assert(mont != NULL);
1325 assert(mont->p != NULL);
1328 if (!EC_to_montgomery(E, mont, ctx)) return 0;
1333 if (!BN_zero(R->Z)) return 0;
1343 if (!BN_zero(R->Z)) return 0;
1348 if (!BN_is_bit_set(k, j))
1350 if (!ECP_mont_double(R, R, E, mont, ctx)) return 0;
1356 if (nextw < -1) nextw = -1;
1358 while(!BN_is_bit_set(k, t))
1363 if (!ECP_mont_double(R, R, E, mont, ctx)) return 0;
1373 if (BN_is_bit_set(k, j)) h++;
1374 if (!ECP_mont_double(R, R, E, mont, ctx)) return 0;
1376 if (!ECP_mont_double(R, R, E, mont, ctx)) return 0;
1380 if (!ECP_mont_add(R, R, prec->Pi[h], E, mont, ctx)) return 0;
1382 for (; j > nextw; j--)
1384 if (!ECP_mont_double(R, R, E, mont, ctx)) return 0;
1394 int ECP_mont_multiply2(EC_POINT *R, BIGNUM *k, EC_POINT *P, EC *E, BN_MONTGOMERY *mont, BN_CTX *ctx)
1402 assert(R->X != NULL && R->Y != NULL && R->Z != NULL);
1405 assert(P->X != NULL && P->Y != NULL && P->Z != NULL);
1408 assert(E->A != NULL && E->B != NULL && E->p != NULL && E->h != NULL);
1413 assert(ctx != NULL);
1415 assert(mont != NULL);
1416 assert(mont->p != NULL);
1419 if (!EC_to_montgomery(E, mont, ctx)) return 0;
1422 if (!ECP_to_montgomery(P, mont, ctx)) return 0;
1427 if (!BN_zero(R->Z)) return 0;
1432 if ((h = BN_dup(k)) == NULL) return 0;
1434 if (!BN_lshift1(h, h)) goto err;
1435 if (!BN_add(h, h, k)) goto err;
1437 if (!ECP_copy(R, P)) goto err;
1438 if ((mP = ECP_mont_minus(P, mont)) == NULL) goto err;
1440 for(j = BN_num_bits(h) - 2; j > 0; j--)
1442 if (!ECP_mont_double(R, R, E, mont, ctx)) goto err;
1443 kj = BN_is_bit_set(k, j);
1444 hj = BN_is_bit_set(h, j);
1445 if (hj == 1 && kj == 0)
1446 if (!ECP_mont_add(R, R, P, E, mont, ctx)) goto err;
1447 if (hj == 0 && kj == 1)
1448 if (!ECP_mont_add(R, R, mP, E, mont, ctx)) goto err;
1451 if (h != NULL) BN_free(h);
1452 if (mP != NULL) ECP_clear_free(mP);
1456 if (h != NULL) BN_free(h);
1457 if (mP != NULL) ECP_clear_free(mP);
1461 #endif /* MONTGOMERY */