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if_iwm - Recognize IWM_FW_PAGING_BLOCK_CMD wide cmd response correctly.
[dragonfly.git] / crypto / openssl / crypto / ec / ec2_smpl.c
blob5b27b91fcc94f33df244dadf525424dc80d0d1da
1 /* crypto/ec/ec2_smpl.c */
2 /* ====================================================================
3 * Copyright 2002 Sun Microsystems, Inc. ALL RIGHTS RESERVED.
4 *
5 * The Elliptic Curve Public-Key Crypto Library (ECC Code) included
6 * herein is developed by SUN MICROSYSTEMS, INC., and is contributed
7 * to the OpenSSL project.
8 *
9 * The ECC Code is licensed pursuant to the OpenSSL open source
10 * license provided below.
11 *
12 * The software is originally written by Sheueling Chang Shantz and
13 * Douglas Stebila of Sun Microsystems Laboratories.
14 *
15 */
16 /* ====================================================================
17 * Copyright (c) 1998-2005 The OpenSSL Project. All rights reserved.
18 *
19 * Redistribution and use in source and binary forms, with or without
20 * modification, are permitted provided that the following conditions
21 * are met:
22 *
23 * 1. Redistributions of source code must retain the above copyright
24 * notice, this list of conditions and the following disclaimer.
25 *
26 * 2. Redistributions in binary form must reproduce the above copyright
27 * notice, this list of conditions and the following disclaimer in
28 * the documentation and/or other materials provided with the
29 * distribution.
30 *
31 * 3. All advertising materials mentioning features or use of this
32 * software must display the following acknowledgment:
33 * "This product includes software developed by the OpenSSL Project
34 * for use in the OpenSSL Toolkit. (http://www.openssl.org/)"
35 *
36 * 4. The names "OpenSSL Toolkit" and "OpenSSL Project" must not be used to
37 * endorse or promote products derived from this software without
38 * prior written permission. For written permission, please contact
39 * openssl-core@openssl.org.
40 *
41 * 5. Products derived from this software may not be called "OpenSSL"
42 * nor may "OpenSSL" appear in their names without prior written
43 * permission of the OpenSSL Project.
44 *
45 * 6. Redistributions of any form whatsoever must retain the following
46 * acknowledgment:
47 * "This product includes software developed by the OpenSSL Project
48 * for use in the OpenSSL Toolkit (http://www.openssl.org/)"
49 *
50 * THIS SOFTWARE IS PROVIDED BY THE OpenSSL PROJECT ``AS IS'' AND ANY
51 * EXPRESSED OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
52 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
53 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE OpenSSL PROJECT OR
54 * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
55 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
56 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
57 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
58 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
59 * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
60 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
61 * OF THE POSSIBILITY OF SUCH DAMAGE.
62 * ====================================================================
63 *
64 * This product includes cryptographic software written by Eric Young
65 * (eay@cryptsoft.com). This product includes software written by Tim
66 * Hudson (tjh@cryptsoft.com).
67 *
68 */
69
70 #include <openssl/err.h>
71
72 #include "ec_lcl.h"
73
74 #ifndef OPENSSL_NO_EC2M
75
76 # ifdef OPENSSL_FIPS
77 # include <openssl/fips.h>
78 # endif
79
80 const EC_METHOD *EC_GF2m_simple_method(void)
81 {
82 static const EC_METHOD ret = {
83 EC_FLAGS_DEFAULT_OCT,
84 NID_X9_62_characteristic_two_field,
85 ec_GF2m_simple_group_init,
86 ec_GF2m_simple_group_finish,
87 ec_GF2m_simple_group_clear_finish,
88 ec_GF2m_simple_group_copy,
89 ec_GF2m_simple_group_set_curve,
90 ec_GF2m_simple_group_get_curve,
91 ec_GF2m_simple_group_get_degree,
92 ec_GF2m_simple_group_check_discriminant,
93 ec_GF2m_simple_point_init,
94 ec_GF2m_simple_point_finish,
95 ec_GF2m_simple_point_clear_finish,
96 ec_GF2m_simple_point_copy,
97 ec_GF2m_simple_point_set_to_infinity,
98 0 /* set_Jprojective_coordinates_GFp */ ,
99 0 /* get_Jprojective_coordinates_GFp */ ,
100 ec_GF2m_simple_point_set_affine_coordinates,
101 ec_GF2m_simple_point_get_affine_coordinates,
102 0, 0, 0,
103 ec_GF2m_simple_add,
104 ec_GF2m_simple_dbl,
105 ec_GF2m_simple_invert,
106 ec_GF2m_simple_is_at_infinity,
107 ec_GF2m_simple_is_on_curve,
108 ec_GF2m_simple_cmp,
109 ec_GF2m_simple_make_affine,
110 ec_GF2m_simple_points_make_affine,
111
112 /*
113 * the following three method functions are defined in ec2_mult.c
114 */
115 ec_GF2m_simple_mul,
116 ec_GF2m_precompute_mult,
117 ec_GF2m_have_precompute_mult,
118
119 ec_GF2m_simple_field_mul,
120 ec_GF2m_simple_field_sqr,
121 ec_GF2m_simple_field_div,
122 0 /* field_encode */ ,
123 0 /* field_decode */ ,
124 0 /* field_set_to_one */
125 };
126
127 # ifdef OPENSSL_FIPS
128 if (FIPS_mode())
129 return fips_ec_gf2m_simple_method();
130 # endif
131
132 return &ret;
133 }
134
135 /*
136 * Initialize a GF(2^m)-based EC_GROUP structure. Note that all other members
137 * are handled by EC_GROUP_new.
138 */
139 int ec_GF2m_simple_group_init(EC_GROUP *group)
140 {
141 BN_init(&group->field);
142 BN_init(&group->a);
143 BN_init(&group->b);
144 return 1;
145 }
146
147 /*
148 * Free a GF(2^m)-based EC_GROUP structure. Note that all other members are
149 * handled by EC_GROUP_free.
150 */
151 void ec_GF2m_simple_group_finish(EC_GROUP *group)
152 {
153 BN_free(&group->field);
154 BN_free(&group->a);
155 BN_free(&group->b);
156 }
157
158 /*
159 * Clear and free a GF(2^m)-based EC_GROUP structure. Note that all other
160 * members are handled by EC_GROUP_clear_free.
161 */
162 void ec_GF2m_simple_group_clear_finish(EC_GROUP *group)
163 {
164 BN_clear_free(&group->field);
165 BN_clear_free(&group->a);
166 BN_clear_free(&group->b);
167 group->poly[0] = 0;
168 group->poly[1] = 0;
169 group->poly[2] = 0;
170 group->poly[3] = 0;
171 group->poly[4] = 0;
172 group->poly[5] = -1;
173 }
174
175 /*
176 * Copy a GF(2^m)-based EC_GROUP structure. Note that all other members are
177 * handled by EC_GROUP_copy.
178 */
179 int ec_GF2m_simple_group_copy(EC_GROUP *dest, const EC_GROUP *src)
180 {
181 int i;
182 if (!BN_copy(&dest->field, &src->field))
183 return 0;
184 if (!BN_copy(&dest->a, &src->a))
185 return 0;
186 if (!BN_copy(&dest->b, &src->b))
187 return 0;
188 dest->poly[0] = src->poly[0];
189 dest->poly[1] = src->poly[1];
190 dest->poly[2] = src->poly[2];
191 dest->poly[3] = src->poly[3];
192 dest->poly[4] = src->poly[4];
193 dest->poly[5] = src->poly[5];
194 if (bn_wexpand(&dest->a, (int)(dest->poly[0] + BN_BITS2 - 1) / BN_BITS2)
195 == NULL)
196 return 0;
197 if (bn_wexpand(&dest->b, (int)(dest->poly[0] + BN_BITS2 - 1) / BN_BITS2)
198 == NULL)
199 return 0;
200 for (i = dest->a.top; i < dest->a.dmax; i++)
201 dest->a.d[i] = 0;
202 for (i = dest->b.top; i < dest->b.dmax; i++)
203 dest->b.d[i] = 0;
204 return 1;
205 }
206
207 /* Set the curve parameters of an EC_GROUP structure. */
208 int ec_GF2m_simple_group_set_curve(EC_GROUP *group,
209 const BIGNUM *p, const BIGNUM *a,
210 const BIGNUM *b, BN_CTX *ctx)
211 {
212 int ret = 0, i;
213
214 /* group->field */
215 if (!BN_copy(&group->field, p))
216 goto err;
217 i = BN_GF2m_poly2arr(&group->field, group->poly, 6) - 1;
218 if ((i != 5) && (i != 3)) {
219 ECerr(EC_F_EC_GF2M_SIMPLE_GROUP_SET_CURVE, EC_R_UNSUPPORTED_FIELD);
220 goto err;
221 }
222
223 /* group->a */
224 if (!BN_GF2m_mod_arr(&group->a, a, group->poly))
225 goto err;
226 if (bn_wexpand(&group->a, (int)(group->poly[0] + BN_BITS2 - 1) / BN_BITS2)
227 == NULL)
228 goto err;
229 for (i = group->a.top; i < group->a.dmax; i++)
230 group->a.d[i] = 0;
231
232 /* group->b */
233 if (!BN_GF2m_mod_arr(&group->b, b, group->poly))
234 goto err;
235 if (bn_wexpand(&group->b, (int)(group->poly[0] + BN_BITS2 - 1) / BN_BITS2)
236 == NULL)
237 goto err;
238 for (i = group->b.top; i < group->b.dmax; i++)
239 group->b.d[i] = 0;
240
241 ret = 1;
242 err:
243 return ret;
244 }
245
246 /*
247 * Get the curve parameters of an EC_GROUP structure. If p, a, or b are NULL
248 * then there values will not be set but the method will return with success.
249 */
250 int ec_GF2m_simple_group_get_curve(const EC_GROUP *group, BIGNUM *p,
251 BIGNUM *a, BIGNUM *b, BN_CTX *ctx)
252 {
253 int ret = 0;
254
255 if (p != NULL) {
256 if (!BN_copy(p, &group->field))
257 return 0;
258 }
259
260 if (a != NULL) {
261 if (!BN_copy(a, &group->a))
262 goto err;
263 }
264
265 if (b != NULL) {
266 if (!BN_copy(b, &group->b))
267 goto err;
268 }
269
270 ret = 1;
271
272 err:
273 return ret;
274 }
275
276 /*
277 * Gets the degree of the field. For a curve over GF(2^m) this is the value
278 * m.
279 */
280 int ec_GF2m_simple_group_get_degree(const EC_GROUP *group)
281 {
282 return BN_num_bits(&group->field) - 1;
283 }
284
285 /*
286 * Checks the discriminant of the curve. y^2 + x*y = x^3 + a*x^2 + b is an
287 * elliptic curve <=> b != 0 (mod p)
288 */
289 int ec_GF2m_simple_group_check_discriminant(const EC_GROUP *group,
290 BN_CTX *ctx)
291 {
292 int ret = 0;
293 BIGNUM *b;
294 BN_CTX *new_ctx = NULL;
295
296 if (ctx == NULL) {
297 ctx = new_ctx = BN_CTX_new();
298 if (ctx == NULL) {
299 ECerr(EC_F_EC_GF2M_SIMPLE_GROUP_CHECK_DISCRIMINANT,
300 ERR_R_MALLOC_FAILURE);
301 goto err;
302 }
303 }
304 BN_CTX_start(ctx);
305 b = BN_CTX_get(ctx);
306 if (b == NULL)
307 goto err;
308
309 if (!BN_GF2m_mod_arr(b, &group->b, group->poly))
310 goto err;
311
312 /*
313 * check the discriminant: y^2 + x*y = x^3 + a*x^2 + b is an elliptic
314 * curve <=> b != 0 (mod p)
315 */
316 if (BN_is_zero(b))
317 goto err;
318
319 ret = 1;
320
321 err:
322 if (ctx != NULL)
323 BN_CTX_end(ctx);
324 if (new_ctx != NULL)
325 BN_CTX_free(new_ctx);
326 return ret;
327 }
328
329 /* Initializes an EC_POINT. */
330 int ec_GF2m_simple_point_init(EC_POINT *point)
331 {
332 BN_init(&point->X);
333 BN_init(&point->Y);
334 BN_init(&point->Z);
335 return 1;
336 }
337
338 /* Frees an EC_POINT. */
339 void ec_GF2m_simple_point_finish(EC_POINT *point)
340 {
341 BN_free(&point->X);
342 BN_free(&point->Y);
343 BN_free(&point->Z);
344 }
345
346 /* Clears and frees an EC_POINT. */
347 void ec_GF2m_simple_point_clear_finish(EC_POINT *point)
348 {
349 BN_clear_free(&point->X);
350 BN_clear_free(&point->Y);
351 BN_clear_free(&point->Z);
352 point->Z_is_one = 0;
353 }
354
355 /*
356 * Copy the contents of one EC_POINT into another. Assumes dest is
357 * initialized.
358 */
359 int ec_GF2m_simple_point_copy(EC_POINT *dest, const EC_POINT *src)
360 {
361 if (!BN_copy(&dest->X, &src->X))
362 return 0;
363 if (!BN_copy(&dest->Y, &src->Y))
364 return 0;
365 if (!BN_copy(&dest->Z, &src->Z))
366 return 0;
367 dest->Z_is_one = src->Z_is_one;
368
369 return 1;
370 }
371
372 /*
373 * Set an EC_POINT to the point at infinity. A point at infinity is
374 * represented by having Z=0.
375 */
376 int ec_GF2m_simple_point_set_to_infinity(const EC_GROUP *group,
377 EC_POINT *point)
378 {
379 point->Z_is_one = 0;
380 BN_zero(&point->Z);
381 return 1;
382 }
383
384 /*
385 * Set the coordinates of an EC_POINT using affine coordinates. Note that
386 * the simple implementation only uses affine coordinates.
387 */
388 int ec_GF2m_simple_point_set_affine_coordinates(const EC_GROUP *group,
389 EC_POINT *point,
390 const BIGNUM *x,
391 const BIGNUM *y, BN_CTX *ctx)
392 {
393 int ret = 0;
394 if (x == NULL || y == NULL) {
395 ECerr(EC_F_EC_GF2M_SIMPLE_POINT_SET_AFFINE_COORDINATES,
396 ERR_R_PASSED_NULL_PARAMETER);
397 return 0;
398 }
399
400 if (!BN_copy(&point->X, x))
401 goto err;
402 BN_set_negative(&point->X, 0);
403 if (!BN_copy(&point->Y, y))
404 goto err;
405 BN_set_negative(&point->Y, 0);
406 if (!BN_copy(&point->Z, BN_value_one()))
407 goto err;
408 BN_set_negative(&point->Z, 0);
409 point->Z_is_one = 1;
410 ret = 1;
411
412 err:
413 return ret;
414 }
415
416 /*
417 * Gets the affine coordinates of an EC_POINT. Note that the simple
418 * implementation only uses affine coordinates.
419 */
420 int ec_GF2m_simple_point_get_affine_coordinates(const EC_GROUP *group,
421 const EC_POINT *point,
422 BIGNUM *x, BIGNUM *y,
423 BN_CTX *ctx)
424 {
425 int ret = 0;
426
427 if (EC_POINT_is_at_infinity(group, point)) {
428 ECerr(EC_F_EC_GF2M_SIMPLE_POINT_GET_AFFINE_COORDINATES,
429 EC_R_POINT_AT_INFINITY);
430 return 0;
431 }
432
433 if (BN_cmp(&point->Z, BN_value_one())) {
434 ECerr(EC_F_EC_GF2M_SIMPLE_POINT_GET_AFFINE_COORDINATES,
435 ERR_R_SHOULD_NOT_HAVE_BEEN_CALLED);
436 return 0;
437 }
438 if (x != NULL) {
439 if (!BN_copy(x, &point->X))
440 goto err;
441 BN_set_negative(x, 0);
442 }
443 if (y != NULL) {
444 if (!BN_copy(y, &point->Y))
445 goto err;
446 BN_set_negative(y, 0);
447 }
448 ret = 1;
449
450 err:
451 return ret;
452 }
453
454 /*
455 * Computes a + b and stores the result in r. r could be a or b, a could be
456 * b. Uses algorithm A.10.2 of IEEE P1363.
457 */
458 int ec_GF2m_simple_add(const EC_GROUP *group, EC_POINT *r, const EC_POINT *a,
459 const EC_POINT *b, BN_CTX *ctx)
460 {
461 BN_CTX *new_ctx = NULL;
462 BIGNUM *x0, *y0, *x1, *y1, *x2, *y2, *s, *t;
463 int ret = 0;
464
465 if (EC_POINT_is_at_infinity(group, a)) {
466 if (!EC_POINT_copy(r, b))
467 return 0;
468 return 1;
469 }
470
471 if (EC_POINT_is_at_infinity(group, b)) {
472 if (!EC_POINT_copy(r, a))
473 return 0;
474 return 1;
475 }
476
477 if (ctx == NULL) {
478 ctx = new_ctx = BN_CTX_new();
479 if (ctx == NULL)
480 return 0;
481 }
482
483 BN_CTX_start(ctx);
484 x0 = BN_CTX_get(ctx);
485 y0 = BN_CTX_get(ctx);
486 x1 = BN_CTX_get(ctx);
487 y1 = BN_CTX_get(ctx);
488 x2 = BN_CTX_get(ctx);
489 y2 = BN_CTX_get(ctx);
490 s = BN_CTX_get(ctx);
491 t = BN_CTX_get(ctx);
492 if (t == NULL)
493 goto err;
494
495 if (a->Z_is_one) {
496 if (!BN_copy(x0, &a->X))
497 goto err;
498 if (!BN_copy(y0, &a->Y))
499 goto err;
500 } else {
501 if (!EC_POINT_get_affine_coordinates_GF2m(group, a, x0, y0, ctx))
502 goto err;
503 }
504 if (b->Z_is_one) {
505 if (!BN_copy(x1, &b->X))
506 goto err;
507 if (!BN_copy(y1, &b->Y))
508 goto err;
509 } else {
510 if (!EC_POINT_get_affine_coordinates_GF2m(group, b, x1, y1, ctx))
511 goto err;
512 }
513
514 if (BN_GF2m_cmp(x0, x1)) {
515 if (!BN_GF2m_add(t, x0, x1))
516 goto err;
517 if (!BN_GF2m_add(s, y0, y1))
518 goto err;
519 if (!group->meth->field_div(group, s, s, t, ctx))
520 goto err;
521 if (!group->meth->field_sqr(group, x2, s, ctx))
522 goto err;
523 if (!BN_GF2m_add(x2, x2, &group->a))
524 goto err;
525 if (!BN_GF2m_add(x2, x2, s))
526 goto err;
527 if (!BN_GF2m_add(x2, x2, t))
528 goto err;
529 } else {
530 if (BN_GF2m_cmp(y0, y1) || BN_is_zero(x1)) {
531 if (!EC_POINT_set_to_infinity(group, r))
532 goto err;
533 ret = 1;
534 goto err;
535 }
536 if (!group->meth->field_div(group, s, y1, x1, ctx))
537 goto err;
538 if (!BN_GF2m_add(s, s, x1))
539 goto err;
540
541 if (!group->meth->field_sqr(group, x2, s, ctx))
542 goto err;
543 if (!BN_GF2m_add(x2, x2, s))
544 goto err;
545 if (!BN_GF2m_add(x2, x2, &group->a))
546 goto err;
547 }
548
549 if (!BN_GF2m_add(y2, x1, x2))
550 goto err;
551 if (!group->meth->field_mul(group, y2, y2, s, ctx))
552 goto err;
553 if (!BN_GF2m_add(y2, y2, x2))
554 goto err;
555 if (!BN_GF2m_add(y2, y2, y1))
556 goto err;
557
558 if (!EC_POINT_set_affine_coordinates_GF2m(group, r, x2, y2, ctx))
559 goto err;
560
561 ret = 1;
562
563 err:
564 BN_CTX_end(ctx);
565 if (new_ctx != NULL)
566 BN_CTX_free(new_ctx);
567 return ret;
568 }
569
570 /*
571 * Computes 2 * a and stores the result in r. r could be a. Uses algorithm
572 * A.10.2 of IEEE P1363.
573 */
574 int ec_GF2m_simple_dbl(const EC_GROUP *group, EC_POINT *r, const EC_POINT *a,
575 BN_CTX *ctx)
576 {
577 return ec_GF2m_simple_add(group, r, a, a, ctx);
578 }
579
580 int ec_GF2m_simple_invert(const EC_GROUP *group, EC_POINT *point, BN_CTX *ctx)
581 {
582 if (EC_POINT_is_at_infinity(group, point) || BN_is_zero(&point->Y))
583 /* point is its own inverse */
584 return 1;
585
586 if (!EC_POINT_make_affine(group, point, ctx))
587 return 0;
588 return BN_GF2m_add(&point->Y, &point->X, &point->Y);
589 }
590
591 /* Indicates whether the given point is the point at infinity. */
592 int ec_GF2m_simple_is_at_infinity(const EC_GROUP *group,
593 const EC_POINT *point)
594 {
595 return BN_is_zero(&point->Z);
596 }
597
598 /*-
599 * Determines whether the given EC_POINT is an actual point on the curve defined
600 * in the EC_GROUP. A point is valid if it satisfies the Weierstrass equation:
601 * y^2 + x*y = x^3 + a*x^2 + b.
602 */
603 int ec_GF2m_simple_is_on_curve(const EC_GROUP *group, const EC_POINT *point,
604 BN_CTX *ctx)
605 {
606 int ret = -1;
607 BN_CTX *new_ctx = NULL;
608 BIGNUM *lh, *y2;
609 int (*field_mul) (const EC_GROUP *, BIGNUM *, const BIGNUM *,
610 const BIGNUM *, BN_CTX *);
611 int (*field_sqr) (const EC_GROUP *, BIGNUM *, const BIGNUM *, BN_CTX *);
612
613 if (EC_POINT_is_at_infinity(group, point))
614 return 1;
615
616 field_mul = group->meth->field_mul;
617 field_sqr = group->meth->field_sqr;
618
619 /* only support affine coordinates */
620 if (!point->Z_is_one)
621 return -1;
622
623 if (ctx == NULL) {
624 ctx = new_ctx = BN_CTX_new();
625 if (ctx == NULL)
626 return -1;
627 }
628
629 BN_CTX_start(ctx);
630 y2 = BN_CTX_get(ctx);
631 lh = BN_CTX_get(ctx);
632 if (lh == NULL)
633 goto err;
634
635 /*-
636 * We have a curve defined by a Weierstrass equation
637 * y^2 + x*y = x^3 + a*x^2 + b.
638 * <=> x^3 + a*x^2 + x*y + b + y^2 = 0
639 * <=> ((x + a) * x + y ) * x + b + y^2 = 0
640 */
641 if (!BN_GF2m_add(lh, &point->X, &group->a))
642 goto err;
643 if (!field_mul(group, lh, lh, &point->X, ctx))
644 goto err;
645 if (!BN_GF2m_add(lh, lh, &point->Y))
646 goto err;
647 if (!field_mul(group, lh, lh, &point->X, ctx))
648 goto err;
649 if (!BN_GF2m_add(lh, lh, &group->b))
650 goto err;
651 if (!field_sqr(group, y2, &point->Y, ctx))
652 goto err;
653 if (!BN_GF2m_add(lh, lh, y2))
654 goto err;
655 ret = BN_is_zero(lh);
656 err:
657 if (ctx)
658 BN_CTX_end(ctx);
659 if (new_ctx)
660 BN_CTX_free(new_ctx);
661 return ret;
662 }
663
664 /*-
665 * Indicates whether two points are equal.
666 * Return values:
667 * -1 error
668 * 0 equal (in affine coordinates)
669 * 1 not equal
670 */
671 int ec_GF2m_simple_cmp(const EC_GROUP *group, const EC_POINT *a,
672 const EC_POINT *b, BN_CTX *ctx)
673 {
674 BIGNUM *aX, *aY, *bX, *bY;
675 BN_CTX *new_ctx = NULL;
676 int ret = -1;
677
678 if (EC_POINT_is_at_infinity(group, a)) {
679 return EC_POINT_is_at_infinity(group, b) ? 0 : 1;
680 }
681
682 if (EC_POINT_is_at_infinity(group, b))
683 return 1;
684
685 if (a->Z_is_one && b->Z_is_one) {
686 return ((BN_cmp(&a->X, &b->X) == 0)
687 && BN_cmp(&a->Y, &b->Y) == 0) ? 0 : 1;
688 }
689
690 if (ctx == NULL) {
691 ctx = new_ctx = BN_CTX_new();
692 if (ctx == NULL)
693 return -1;
694 }
695
696 BN_CTX_start(ctx);
697 aX = BN_CTX_get(ctx);
698 aY = BN_CTX_get(ctx);
699 bX = BN_CTX_get(ctx);
700 bY = BN_CTX_get(ctx);
701 if (bY == NULL)
702 goto err;
703
704 if (!EC_POINT_get_affine_coordinates_GF2m(group, a, aX, aY, ctx))
705 goto err;
706 if (!EC_POINT_get_affine_coordinates_GF2m(group, b, bX, bY, ctx))
707 goto err;
708 ret = ((BN_cmp(aX, bX) == 0) && BN_cmp(aY, bY) == 0) ? 0 : 1;
709
710 err:
711 if (ctx)
712 BN_CTX_end(ctx);
713 if (new_ctx)
714 BN_CTX_free(new_ctx);
715 return ret;
716 }
717
718 /* Forces the given EC_POINT to internally use affine coordinates. */
719 int ec_GF2m_simple_make_affine(const EC_GROUP *group, EC_POINT *point,
720 BN_CTX *ctx)
721 {
722 BN_CTX *new_ctx = NULL;
723 BIGNUM *x, *y;
724 int ret = 0;
725
726 if (point->Z_is_one || EC_POINT_is_at_infinity(group, point))
727 return 1;
728
729 if (ctx == NULL) {
730 ctx = new_ctx = BN_CTX_new();
731 if (ctx == NULL)
732 return 0;
733 }
734
735 BN_CTX_start(ctx);
736 x = BN_CTX_get(ctx);
737 y = BN_CTX_get(ctx);
738 if (y == NULL)
739 goto err;
740
741 if (!EC_POINT_get_affine_coordinates_GF2m(group, point, x, y, ctx))
742 goto err;
743 if (!BN_copy(&point->X, x))
744 goto err;
745 if (!BN_copy(&point->Y, y))
746 goto err;
747 if (!BN_one(&point->Z))
748 goto err;
749 point->Z_is_one = 1;
750
751 ret = 1;
752
753 err:
754 if (ctx)
755 BN_CTX_end(ctx);
756 if (new_ctx)
757 BN_CTX_free(new_ctx);
758 return ret;
759 }
760
761 /*
762 * Forces each of the EC_POINTs in the given array to use affine coordinates.
763 */
764 int ec_GF2m_simple_points_make_affine(const EC_GROUP *group, size_t num,
765 EC_POINT *points[], BN_CTX *ctx)
766 {
767 size_t i;
768
769 for (i = 0; i < num; i++) {
770 if (!group->meth->make_affine(group, points[i], ctx))
771 return 0;
772 }
773
774 return 1;
775 }
776
777 /* Wrapper to simple binary polynomial field multiplication implementation. */
778 int ec_GF2m_simple_field_mul(const EC_GROUP *group, BIGNUM *r,
779 const BIGNUM *a, const BIGNUM *b, BN_CTX *ctx)
780 {
781 return BN_GF2m_mod_mul_arr(r, a, b, group->poly, ctx);
782 }
783
784 /* Wrapper to simple binary polynomial field squaring implementation. */
785 int ec_GF2m_simple_field_sqr(const EC_GROUP *group, BIGNUM *r,
786 const BIGNUM *a, BN_CTX *ctx)
787 {
788 return BN_GF2m_mod_sqr_arr(r, a, group->poly, ctx);
789 }
790
791 /* Wrapper to simple binary polynomial field division implementation. */
792 int ec_GF2m_simple_field_div(const EC_GROUP *group, BIGNUM *r,
793 const BIGNUM *a, const BIGNUM *b, BN_CTX *ctx)
794 {
795 return BN_GF2m_mod_div(r, a, b, &group->field, ctx);
796 }
797
798 #endif
DragonFly BSD