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[thirdparty/openssl.git] / crypto / ec / ecp_nistz256.c
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4d3fa06f
AP		 1/******************************************************************************
2 * *
3 * Copyright 2014 Intel Corporation *
4 * *
5 * Licensed under the Apache License, Version 2.0 (the "License"); *
6 * you may not use this file except in compliance with the License. *
7 * You may obtain a copy of the License at *
8 * *
9 * http://www.apache.org/licenses/LICENSE-2.0 *
10 * *
11 * Unless required by applicable law or agreed to in writing, software *
12 * distributed under the License is distributed on an "AS IS" BASIS, *
13 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. *
14 * See the License for the specific language governing permissions and *
15 * limitations under the License. *
16 * *
17 ******************************************************************************
18 * *
19 * Developers and authors: *
20 * Shay Gueron (1, 2), and Vlad Krasnov (1) *
21 * (1) Intel Corporation, Israel Development Center *
22 * (2) University of Haifa *
23 * Reference: *
24 * S.Gueron and V.Krasnov, "Fast Prime Field Elliptic Curve Cryptography with *
25 * 256 Bit Primes" *
26 * *
27 ******************************************************************************/
28
29#include <string.h>
30
b39fc560 31#include "internal/cryptlib.h"
5afc296a 32#include "internal/bn_int.h"
4d3fa06f
AP		 33#include "ec_lcl.h"
34
35#if BN_BITS2 != 64
58d47cf0 36# define TOBN(hi,lo) lo,hi
4d3fa06f 37#else
58d47cf0 38# define TOBN(hi,lo) ((BN_ULONG)hi<<32|lo)
4d3fa06f
AP		 39#endif
40
41#if defined(__GNUC__)
58d47cf0 42# define ALIGN32 __attribute((aligned(32)))
4d3fa06f 43#elif defined(_MSC_VER)
58d47cf0 44# define ALIGN32 __declspec(align(32))
4d3fa06f
AP		 45#else
46# define ALIGN32
47#endif
48
58d47cf0
AP		 49#define ALIGNPTR(p,N) ((unsigned char *)p+N-(size_t)p%N)
50#define P256_LIMBS (256/BN_BITS2)
4d3fa06f
AP		 51
52typedef unsigned short u16;
53
54typedef struct {
55 BN_ULONG X[P256_LIMBS];
56 BN_ULONG Y[P256_LIMBS];
57 BN_ULONG Z[P256_LIMBS];
58} P256_POINT;
59
60typedef struct {
61 BN_ULONG X[P256_LIMBS];
62 BN_ULONG Y[P256_LIMBS];
63} P256_POINT_AFFINE;
64
65typedef P256_POINT_AFFINE PRECOMP256_ROW[64];
66
67/* structure for precomputed multiples of the generator */
3aef36ff 68struct nistz256_pre_comp_st {
4d3fa06f
AP		 69 const EC_GROUP *group; /* Parent EC_GROUP object */
70 size_t w; /* Window size */
20728adc
AP		 71 /*
72 * Constant time access to the X and Y coordinates of the pre-computed,
4d3fa06f 73 * generator multiplies, in the Montgomery domain. Pre-calculated
20728adc
AP		 74 * multiplies are stored in affine form.
75 */
4d3fa06f
AP		 76 PRECOMP256_ROW *precomp;
77 void *precomp_storage;
78 int references;
9b398ef2 79 CRYPTO_RWLOCK *lock;
3aef36ff 80};
4d3fa06f
AP		 81
82/* Functions implemented in assembly */
83/* Modular mul by 2: res = 2*a mod P */
84void ecp_nistz256_mul_by_2(BN_ULONG res[P256_LIMBS],
85 const BN_ULONG a[P256_LIMBS]);
86/* Modular div by 2: res = a/2 mod P */
87void ecp_nistz256_div_by_2(BN_ULONG res[P256_LIMBS],
88 const BN_ULONG a[P256_LIMBS]);
89/* Modular mul by 3: res = 3*a mod P */
90void ecp_nistz256_mul_by_3(BN_ULONG res[P256_LIMBS],
91 const BN_ULONG a[P256_LIMBS]);
20728adc 92/* Modular add: res = a+b mod P */
4d3fa06f
AP		 93void ecp_nistz256_add(BN_ULONG res[P256_LIMBS],
94 const BN_ULONG a[P256_LIMBS],
95 const BN_ULONG b[P256_LIMBS]);
20728adc 96/* Modular sub: res = a-b mod P */
4d3fa06f
AP		 97void ecp_nistz256_sub(BN_ULONG res[P256_LIMBS],
98 const BN_ULONG a[P256_LIMBS],
99 const BN_ULONG b[P256_LIMBS]);
20728adc 100/* Modular neg: res = -a mod P */
4d3fa06f
AP		 101void ecp_nistz256_neg(BN_ULONG res[P256_LIMBS], const BN_ULONG a[P256_LIMBS]);
102/* Montgomery mul: res = a*b*2^-256 mod P */
103void ecp_nistz256_mul_mont(BN_ULONG res[P256_LIMBS],
104 const BN_ULONG a[P256_LIMBS],
105 const BN_ULONG b[P256_LIMBS]);
106/* Montgomery sqr: res = a*a*2^-256 mod P */
107void ecp_nistz256_sqr_mont(BN_ULONG res[P256_LIMBS],
108 const BN_ULONG a[P256_LIMBS]);
109/* Convert a number from Montgomery domain, by multiplying with 1 */
110void ecp_nistz256_from_mont(BN_ULONG res[P256_LIMBS],
111 const BN_ULONG in[P256_LIMBS]);
112/* Convert a number to Montgomery domain, by multiplying with 2^512 mod P*/
113void ecp_nistz256_to_mont(BN_ULONG res[P256_LIMBS],
114 const BN_ULONG in[P256_LIMBS]);
115/* Functions that perform constant time access to the precomputed tables */
58d47cf0 116void ecp_nistz256_scatter_w5(P256_POINT *val,
49b05c7d 117 const P256_POINT *in_t, int idx);
20728adc 118void ecp_nistz256_gather_w5(P256_POINT *val,
49b05c7d 119 const P256_POINT *in_t, int idx);
58d47cf0 120void ecp_nistz256_scatter_w7(P256_POINT_AFFINE *val,
49b05c7d 121 const P256_POINT_AFFINE *in_t, int idx);
58d47cf0 122void ecp_nistz256_gather_w7(P256_POINT_AFFINE *val,
49b05c7d 123 const P256_POINT_AFFINE *in_t, int idx);
4d3fa06f
AP		 124
125/* One converted into the Montgomery domain */
126static const BN_ULONG ONE[P256_LIMBS] = {
127 TOBN(0x00000000, 0x00000001), TOBN(0xffffffff, 0x00000000),
128 TOBN(0xffffffff, 0xffffffff), TOBN(0x00000000, 0xfffffffe)
129};
130
3aef36ff 131static NISTZ256_PRE_COMP *ecp_nistz256_pre_comp_new(const EC_GROUP *group);
4d3fa06f
AP		 132
133/* Precomputed tables for the default generator */
3ff08e1d 134extern const PRECOMP256_ROW ecp_nistz256_precomputed[37];
4d3fa06f
AP		 135
136/* Recode window to a signed digit, see ecp_nistputil.c for details */
137static unsigned int _booth_recode_w5(unsigned int in)
138{
139 unsigned int s, d;
140
141 s = ~((in >> 5) - 1);
142 d = (1 << 6) - in - 1;
143 d = (d & s) | (in & ~s);
144 d = (d >> 1) + (d & 1);
145
146 return (d << 1) + (s & 1);
147}
148
149static unsigned int _booth_recode_w7(unsigned int in)
150{
151 unsigned int s, d;
152
153 s = ~((in >> 7) - 1);
154 d = (1 << 8) - in - 1;
155 d = (d & s) | (in & ~s);
156 d = (d >> 1) + (d & 1);
157
158 return (d << 1) + (s & 1);
159}
160
161static void copy_conditional(BN_ULONG dst[P256_LIMBS],
162 const BN_ULONG src[P256_LIMBS], BN_ULONG move)
163{
5afc296a 164 BN_ULONG mask1 = 0-move;
4d3fa06f
AP		 165 BN_ULONG mask2 = ~mask1;
166
167 dst[0] = (src[0] & mask1) ^ (dst[0] & mask2);
168 dst[1] = (src[1] & mask1) ^ (dst[1] & mask2);
169 dst[2] = (src[2] & mask1) ^ (dst[2] & mask2);
170 dst[3] = (src[3] & mask1) ^ (dst[3] & mask2);
171 if (P256_LIMBS == 8) {
172 dst[4] = (src[4] & mask1) ^ (dst[4] & mask2);
173 dst[5] = (src[5] & mask1) ^ (dst[5] & mask2);
174 dst[6] = (src[6] & mask1) ^ (dst[6] & mask2);
175 dst[7] = (src[7] & mask1) ^ (dst[7] & mask2);
176 }
177}
178
179static BN_ULONG is_zero(BN_ULONG in)
180{
181 in |= (0 - in);
182 in = ~in;
4d3fa06f
AP		 183 in >>= BN_BITS2 - 1;
184 return in;
185}
186
187static BN_ULONG is_equal(const BN_ULONG a[P256_LIMBS],
188 const BN_ULONG b[P256_LIMBS])
189{
190 BN_ULONG res;
191
192 res = a[0] ^ b[0];
193 res |= a[1] ^ b[1];
194 res |= a[2] ^ b[2];
195 res |= a[3] ^ b[3];
196 if (P256_LIMBS == 8) {
197 res |= a[4] ^ b[4];
198 res |= a[5] ^ b[5];
199 res |= a[6] ^ b[6];
200 res |= a[7] ^ b[7];
201 }
202
203 return is_zero(res);
204}
205
206static BN_ULONG is_one(const BN_ULONG a[P256_LIMBS])
207{
208 BN_ULONG res;
209
210 res = a[0] ^ ONE[0];
211 res |= a[1] ^ ONE[1];
212 res |= a[2] ^ ONE[2];
213 res |= a[3] ^ ONE[3];
214 if (P256_LIMBS == 8) {
215 res |= a[4] ^ ONE[4];
216 res |= a[5] ^ ONE[5];
217 res |= a[6] ^ ONE[6];
218 }
219
220 return is_zero(res);
221}
222
223#ifndef ECP_NISTZ256_REFERENCE_IMPLEMENTATION
58d47cf0
AP		 224void ecp_nistz256_point_double(P256_POINT *r, const P256_POINT *a);
225void ecp_nistz256_point_add(P256_POINT *r,
226 const P256_POINT *a, const P256_POINT *b);
227void ecp_nistz256_point_add_affine(P256_POINT *r,
228 const P256_POINT *a,
229 const P256_POINT_AFFINE *b);
4d3fa06f
AP		 230#else
231/* Point double: r = 2*a */
58d47cf0 232static void ecp_nistz256_point_double(P256_POINT *r, const P256_POINT *a)
4d3fa06f
AP		 233{
234 BN_ULONG S[P256_LIMBS];
235 BN_ULONG M[P256_LIMBS];
236 BN_ULONG Zsqr[P256_LIMBS];
237 BN_ULONG tmp0[P256_LIMBS];
238
239 const BN_ULONG *in_x = a->X;
240 const BN_ULONG *in_y = a->Y;
241 const BN_ULONG *in_z = a->Z;
242
243 BN_ULONG *res_x = r->X;
244 BN_ULONG *res_y = r->Y;
245 BN_ULONG *res_z = r->Z;
246
247 ecp_nistz256_mul_by_2(S, in_y);
248
249 ecp_nistz256_sqr_mont(Zsqr, in_z);
250
251 ecp_nistz256_sqr_mont(S, S);
252
253 ecp_nistz256_mul_mont(res_z, in_z, in_y);
254 ecp_nistz256_mul_by_2(res_z, res_z);
255
256 ecp_nistz256_add(M, in_x, Zsqr);
257 ecp_nistz256_sub(Zsqr, in_x, Zsqr);
258
259 ecp_nistz256_sqr_mont(res_y, S);
260 ecp_nistz256_div_by_2(res_y, res_y);
261
262 ecp_nistz256_mul_mont(M, M, Zsqr);
263 ecp_nistz256_mul_by_3(M, M);
264
265 ecp_nistz256_mul_mont(S, S, in_x);
266 ecp_nistz256_mul_by_2(tmp0, S);
267
268 ecp_nistz256_sqr_mont(res_x, M);
269
270 ecp_nistz256_sub(res_x, res_x, tmp0);
271 ecp_nistz256_sub(S, S, res_x);
272
273 ecp_nistz256_mul_mont(S, S, M);
274 ecp_nistz256_sub(res_y, S, res_y);
275}
276
277/* Point addition: r = a+b */
20728adc
AP		 278static void ecp_nistz256_point_add(P256_POINT *r,
279 const P256_POINT *a, const P256_POINT *b)
4d3fa06f
AP		 280{
281 BN_ULONG U2[P256_LIMBS], S2[P256_LIMBS];
282 BN_ULONG U1[P256_LIMBS], S1[P256_LIMBS];
283 BN_ULONG Z1sqr[P256_LIMBS];
284 BN_ULONG Z2sqr[P256_LIMBS];
285 BN_ULONG H[P256_LIMBS], R[P256_LIMBS];
286 BN_ULONG Hsqr[P256_LIMBS];
287 BN_ULONG Rsqr[P256_LIMBS];
288 BN_ULONG Hcub[P256_LIMBS];
289
290 BN_ULONG res_x[P256_LIMBS];
291 BN_ULONG res_y[P256_LIMBS];
292 BN_ULONG res_z[P256_LIMBS];
293
294 BN_ULONG in1infty, in2infty;
295
296 const BN_ULONG *in1_x = a->X;
297 const BN_ULONG *in1_y = a->Y;
298 const BN_ULONG *in1_z = a->Z;
299
300 const BN_ULONG *in2_x = b->X;
301 const BN_ULONG *in2_y = b->Y;
302 const BN_ULONG *in2_z = b->Z;
303
304 /* We encode infinity as (0,0), which is not on the curve,
305 * so it is OK. */
58d47cf0
AP		 306 in1infty = (in1_x[0] | in1_x[1] | in1_x[2] | in1_x[3] |
307 in1_y[0] | in1_y[1] | in1_y[2] | in1_y[3]);
4d3fa06f 308 if (P256_LIMBS == 8)
58d47cf0
AP		 309 in1infty |= (in1_x[4] | in1_x[5] | in1_x[6] | in1_x[7] |
310 in1_y[4] | in1_y[5] | in1_y[6] | in1_y[7]);
4d3fa06f 311
58d47cf0
AP		 312 in2infty = (in2_x[0] | in2_x[1] | in2_x[2] | in2_x[3] |
313 in2_y[0] | in2_y[1] | in2_y[2] | in2_y[3]);
4d3fa06f 314 if (P256_LIMBS == 8)
58d47cf0
AP		 315 in2infty |= (in2_x[4] | in2_x[5] | in2_x[6] | in2_x[7] |
316 in2_y[4] | in2_y[5] | in2_y[6] | in2_y[7]);
4d3fa06f
AP		 317
318 in1infty = is_zero(in1infty);
319 in2infty = is_zero(in2infty);
320
321 ecp_nistz256_sqr_mont(Z2sqr, in2_z); /* Z2^2 */
322 ecp_nistz256_sqr_mont(Z1sqr, in1_z); /* Z1^2 */
323
324 ecp_nistz256_mul_mont(S1, Z2sqr, in2_z); /* S1 = Z2^3 */
325 ecp_nistz256_mul_mont(S2, Z1sqr, in1_z); /* S2 = Z1^3 */
326
327 ecp_nistz256_mul_mont(S1, S1, in1_y); /* S1 = Y1*Z2^3 */
328 ecp_nistz256_mul_mont(S2, S2, in2_y); /* S2 = Y2*Z1^3 */
329 ecp_nistz256_sub(R, S2, S1); /* R = S2 - S1 */
330
331 ecp_nistz256_mul_mont(U1, in1_x, Z2sqr); /* U1 = X1*Z2^2 */
332 ecp_nistz256_mul_mont(U2, in2_x, Z1sqr); /* U2 = X2*Z1^2 */
333 ecp_nistz256_sub(H, U2, U1); /* H = U2 - U1 */
334
20728adc
AP		 335 /*
336 * This should not happen during sign/ecdh, so no constant time violation
337 */
4d3fa06f
AP		 338 if (is_equal(U1, U2) && !in1infty && !in2infty) {
339 if (is_equal(S1, S2)) {
340 ecp_nistz256_point_double(r, a);
341 return;
342 } else {
343 memset(r, 0, sizeof(*r));
344 return;
345 }
346 }
347
348 ecp_nistz256_sqr_mont(Rsqr, R); /* R^2 */
349 ecp_nistz256_mul_mont(res_z, H, in1_z); /* Z3 = H*Z1*Z2 */
350 ecp_nistz256_sqr_mont(Hsqr, H); /* H^2 */
351 ecp_nistz256_mul_mont(res_z, res_z, in2_z); /* Z3 = H*Z1*Z2 */
352 ecp_nistz256_mul_mont(Hcub, Hsqr, H); /* H^3 */
353
354 ecp_nistz256_mul_mont(U2, U1, Hsqr); /* U1*H^2 */
355 ecp_nistz256_mul_by_2(Hsqr, U2); /* 2*U1*H^2 */
356
357 ecp_nistz256_sub(res_x, Rsqr, Hsqr);
358 ecp_nistz256_sub(res_x, res_x, Hcub);
359
360 ecp_nistz256_sub(res_y, U2, res_x);
361
362 ecp_nistz256_mul_mont(S2, S1, Hcub);
363 ecp_nistz256_mul_mont(res_y, R, res_y);
364 ecp_nistz256_sub(res_y, res_y, S2);
365
366 copy_conditional(res_x, in2_x, in1infty);
367 copy_conditional(res_y, in2_y, in1infty);
368 copy_conditional(res_z, in2_z, in1infty);
369
370 copy_conditional(res_x, in1_x, in2infty);
371 copy_conditional(res_y, in1_y, in2infty);
372 copy_conditional(res_z, in1_z, in2infty);
373
374 memcpy(r->X, res_x, sizeof(res_x));
375 memcpy(r->Y, res_y, sizeof(res_y));
376 memcpy(r->Z, res_z, sizeof(res_z));
377}
378
379/* Point addition when b is known to be affine: r = a+b */
58d47cf0
AP		 380static void ecp_nistz256_point_add_affine(P256_POINT *r,
381 const P256_POINT *a,
382 const P256_POINT_AFFINE *b)
4d3fa06f
AP		 383{
384 BN_ULONG U2[P256_LIMBS], S2[P256_LIMBS];
385 BN_ULONG Z1sqr[P256_LIMBS];
386 BN_ULONG H[P256_LIMBS], R[P256_LIMBS];
387 BN_ULONG Hsqr[P256_LIMBS];
388 BN_ULONG Rsqr[P256_LIMBS];
389 BN_ULONG Hcub[P256_LIMBS];
390
391 BN_ULONG res_x[P256_LIMBS];
392 BN_ULONG res_y[P256_LIMBS];
393 BN_ULONG res_z[P256_LIMBS];
394
395 BN_ULONG in1infty, in2infty;
396
397 const BN_ULONG *in1_x = a->X;
398 const BN_ULONG *in1_y = a->Y;
399 const BN_ULONG *in1_z = a->Z;
400
401 const BN_ULONG *in2_x = b->X;
402 const BN_ULONG *in2_y = b->Y;
403
20728adc
AP		 404 /*
405 * In affine representation we encode infty as (0,0), which is not on the
406 * curve, so it is OK
407 */
58d47cf0
AP		 408 in1infty = (in1_x[0] | in1_x[1] | in1_x[2] | in1_x[3] |
409 in1_y[0] | in1_y[1] | in1_y[2] | in1_y[3]);
4d3fa06f 410 if (P256_LIMBS == 8)
58d47cf0
AP		 411 in1infty |= (in1_x[4] | in1_x[5] | in1_x[6] | in1_x[7] |
412 in1_y[4] | in1_y[5] | in1_y[6] | in1_y[7]);
4d3fa06f 413
58d47cf0
AP		 414 in2infty = (in2_x[0] | in2_x[1] | in2_x[2] | in2_x[3] |
415 in2_y[0] | in2_y[1] | in2_y[2] | in2_y[3]);
4d3fa06f 416 if (P256_LIMBS == 8)
58d47cf0
AP		 417 in2infty |= (in2_x[4] | in2_x[5] | in2_x[6] | in2_x[7] |
418 in2_y[4] | in2_y[5] | in2_y[6] | in2_y[7]);
4d3fa06f
AP		 419
420 in1infty = is_zero(in1infty);
421 in2infty = is_zero(in2infty);
422
423 ecp_nistz256_sqr_mont(Z1sqr, in1_z); /* Z1^2 */
424
425 ecp_nistz256_mul_mont(U2, in2_x, Z1sqr); /* U2 = X2*Z1^2 */
426 ecp_nistz256_sub(H, U2, in1_x); /* H = U2 - U1 */
427
428 ecp_nistz256_mul_mont(S2, Z1sqr, in1_z); /* S2 = Z1^3 */
429
430 ecp_nistz256_mul_mont(res_z, H, in1_z); /* Z3 = H*Z1*Z2 */
431
432 ecp_nistz256_mul_mont(S2, S2, in2_y); /* S2 = Y2*Z1^3 */
433 ecp_nistz256_sub(R, S2, in1_y); /* R = S2 - S1 */
434
435 ecp_nistz256_sqr_mont(Hsqr, H); /* H^2 */
436 ecp_nistz256_sqr_mont(Rsqr, R); /* R^2 */
437 ecp_nistz256_mul_mont(Hcub, Hsqr, H); /* H^3 */
438
439 ecp_nistz256_mul_mont(U2, in1_x, Hsqr); /* U1*H^2 */
440 ecp_nistz256_mul_by_2(Hsqr, U2); /* 2*U1*H^2 */
441
442 ecp_nistz256_sub(res_x, Rsqr, Hsqr);
443 ecp_nistz256_sub(res_x, res_x, Hcub);
444 ecp_nistz256_sub(H, U2, res_x);
445
446 ecp_nistz256_mul_mont(S2, in1_y, Hcub);
447 ecp_nistz256_mul_mont(H, H, R);
448 ecp_nistz256_sub(res_y, H, S2);
449
450 copy_conditional(res_x, in2_x, in1infty);
451 copy_conditional(res_x, in1_x, in2infty);
452
453 copy_conditional(res_y, in2_y, in1infty);
454 copy_conditional(res_y, in1_y, in2infty);
455
456 copy_conditional(res_z, ONE, in1infty);
457 copy_conditional(res_z, in1_z, in2infty);
458
459 memcpy(r->X, res_x, sizeof(res_x));
460 memcpy(r->Y, res_y, sizeof(res_y));
461 memcpy(r->Z, res_z, sizeof(res_z));
462}
463#endif
464
465/* r = in^-1 mod p */
466static void ecp_nistz256_mod_inverse(BN_ULONG r[P256_LIMBS],
467 const BN_ULONG in[P256_LIMBS])
468{
20728adc
AP		 469 /*
470 * The poly is ffffffff 00000001 00000000 00000000 00000000 ffffffff
471 * ffffffff ffffffff We use FLT and used poly-2 as exponent
472 */
4d3fa06f
AP		 473 BN_ULONG p2[P256_LIMBS];
474 BN_ULONG p4[P256_LIMBS];
475 BN_ULONG p8[P256_LIMBS];
476 BN_ULONG p16[P256_LIMBS];
477 BN_ULONG p32[P256_LIMBS];
478 BN_ULONG res[P256_LIMBS];
479 int i;
480
481 ecp_nistz256_sqr_mont(res, in);
482 ecp_nistz256_mul_mont(p2, res, in); /* 3*p */
483
484 ecp_nistz256_sqr_mont(res, p2);
485 ecp_nistz256_sqr_mont(res, res);
486 ecp_nistz256_mul_mont(p4, res, p2); /* f*p */
487
488 ecp_nistz256_sqr_mont(res, p4);
489 ecp_nistz256_sqr_mont(res, res);
490 ecp_nistz256_sqr_mont(res, res);
491 ecp_nistz256_sqr_mont(res, res);
492 ecp_nistz256_mul_mont(p8, res, p4); /* ff*p */
493
494 ecp_nistz256_sqr_mont(res, p8);
495 for (i = 0; i < 7; i++)
496 ecp_nistz256_sqr_mont(res, res);
497 ecp_nistz256_mul_mont(p16, res, p8); /* ffff*p */
498
499 ecp_nistz256_sqr_mont(res, p16);
500 for (i = 0; i < 15; i++)
501 ecp_nistz256_sqr_mont(res, res);
502 ecp_nistz256_mul_mont(p32, res, p16); /* ffffffff*p */
503
504 ecp_nistz256_sqr_mont(res, p32);
505 for (i = 0; i < 31; i++)
506 ecp_nistz256_sqr_mont(res, res);
507 ecp_nistz256_mul_mont(res, res, in);
508
509 for (i = 0; i < 32 * 4; i++)
510 ecp_nistz256_sqr_mont(res, res);
511 ecp_nistz256_mul_mont(res, res, p32);
512
513 for (i = 0; i < 32; i++)
514 ecp_nistz256_sqr_mont(res, res);
515 ecp_nistz256_mul_mont(res, res, p32);
516
517 for (i = 0; i < 16; i++)
518 ecp_nistz256_sqr_mont(res, res);
519 ecp_nistz256_mul_mont(res, res, p16);
520
521 for (i = 0; i < 8; i++)
522 ecp_nistz256_sqr_mont(res, res);
523 ecp_nistz256_mul_mont(res, res, p8);
524
525 ecp_nistz256_sqr_mont(res, res);
526 ecp_nistz256_sqr_mont(res, res);
527 ecp_nistz256_sqr_mont(res, res);
528 ecp_nistz256_sqr_mont(res, res);
529 ecp_nistz256_mul_mont(res, res, p4);
530
531 ecp_nistz256_sqr_mont(res, res);
532 ecp_nistz256_sqr_mont(res, res);
533 ecp_nistz256_mul_mont(res, res, p2);
534
535 ecp_nistz256_sqr_mont(res, res);
536 ecp_nistz256_sqr_mont(res, res);
537 ecp_nistz256_mul_mont(res, res, in);
538
539 memcpy(r, res, sizeof(res));
540}
541
20728adc
AP		 542/*
543 * ecp_nistz256_bignum_to_field_elem copies the contents of |in| to |out| and
544 * returns one if it fits. Otherwise it returns zero.
545 */
5956b110
EK		 546__owur static int ecp_nistz256_bignum_to_field_elem(BN_ULONG out[P256_LIMBS],
547 const BIGNUM *in)
4d3fa06f 548{
5784a521 549 return bn_copy_words(out, in, P256_LIMBS);
4d3fa06f
AP		 550}
551
552/* r = sum(scalar[i]*point[i]) */
5956b110
EK		 553__owur static int ecp_nistz256_windowed_mul(const EC_GROUP *group,
554 P256_POINT *r,
555 const BIGNUM **scalar,
556 const EC_POINT **point,
557 size_t num, BN_CTX *ctx)
4d3fa06f 558{
5afc296a 559 size_t i;
a4d5269e 560 int j, ret = 0;
49b05c7d 561 unsigned int idx;
4d3fa06f
AP		 562 unsigned char (*p_str)[33] = NULL;
563 const unsigned int window_size = 5;
564 const unsigned int mask = (1 << (window_size + 1)) - 1;
565 unsigned int wvalue;
20728adc 566 P256_POINT *temp; /* place for 5 temporary points */
4d3fa06f 567 const BIGNUM **scalars = NULL;
20728adc 568 P256_POINT (*table)[16] = NULL;
4d3fa06f
AP		 569 void *table_storage = NULL;
570
5afc296a
AP		 571 if ((num * 16 + 6) > OPENSSL_MALLOC_MAX_NELEMS(P256_POINT)
572 || (table_storage =
573 OPENSSL_malloc((num * 16 + 5) * sizeof(P256_POINT) + 64)) == NULL
4d3fa06f
AP		 574 || (p_str =
575 OPENSSL_malloc(num * 33 * sizeof(unsigned char))) == NULL
576 || (scalars = OPENSSL_malloc(num * sizeof(BIGNUM *))) == NULL) {
be07ae9b 577 ECerr(EC_F_ECP_NISTZ256_WINDOWED_MUL, ERR_R_MALLOC_FAILURE);
4d3fa06f 578 goto err;
4d3fa06f
AP		 579 }
580
3ff08e1d 581 table = (void *)ALIGNPTR(table_storage, 64);
20728adc 582 temp = (P256_POINT *)(table + num);
3ff08e1d 583
4d3fa06f
AP		 584 for (i = 0; i < num; i++) {
585 P256_POINT *row = table[i];
586
c028254b 587 /* This is an unusual input, we don't guarantee constant-timeness. */
4d3fa06f
AP		 588 if ((BN_num_bits(scalar[i]) > 256) || BN_is_negative(scalar[i])) {
589 BIGNUM *mod;
590
591 if ((mod = BN_CTX_get(ctx)) == NULL)
592 goto err;
5784a521 593 if (!BN_nnmod(mod, scalar[i], group->order, ctx)) {
be07ae9b 594 ECerr(EC_F_ECP_NISTZ256_WINDOWED_MUL, ERR_R_BN_LIB);
4d3fa06f
AP		 595 goto err;
596 }
597 scalars[i] = mod;
598 } else
599 scalars[i] = scalar[i];
600
5784a521
MC		 601 for (j = 0; j < bn_get_top(scalars[i]) * BN_BYTES; j += BN_BYTES) {
602 BN_ULONG d = bn_get_words(scalars[i])[j / BN_BYTES];
4d3fa06f 603
5afc296a
AP		 604 p_str[i][j + 0] = (unsigned char)d;
605 p_str[i][j + 1] = (unsigned char)(d >> 8);
606 p_str[i][j + 2] = (unsigned char)(d >> 16);
607 p_str[i][j + 3] = (unsigned char)(d >>= 24);
4d3fa06f
AP		 608 if (BN_BYTES == 8) {
609 d >>= 8;
5afc296a
AP		 610 p_str[i][j + 4] = (unsigned char)d;
611 p_str[i][j + 5] = (unsigned char)(d >> 8);
612 p_str[i][j + 6] = (unsigned char)(d >> 16);
613 p_str[i][j + 7] = (unsigned char)(d >> 24);
4d3fa06f
AP		 614 }
615 }
616 for (; j < 33; j++)
617 p_str[i][j] = 0;
618
5784a521
MC		 619 if (!ecp_nistz256_bignum_to_field_elem(temp[0].X, point[i]->X)
620 || !ecp_nistz256_bignum_to_field_elem(temp[0].Y, point[i]->Y)
621 || !ecp_nistz256_bignum_to_field_elem(temp[0].Z, point[i]->Z)) {
58d47cf0
AP		 622 ECerr(EC_F_ECP_NISTZ256_WINDOWED_MUL,
623 EC_R_COORDINATES_OUT_OF_RANGE);
4d3fa06f
AP		 624 goto err;
625 }
626
20728adc 627 /*
dccd20d1
F		 628 * row[0] is implicitly (0,0,0) (the point at infinity), therefore it
629 * is not stored. All other values are actually stored with an offset
630 * of -1 in table.
3ff08e1d
AP		 631 */
632
633 ecp_nistz256_scatter_w5 (row, &temp[0], 1);
634 ecp_nistz256_point_double(&temp[1], &temp[0]); /*1+1=2 */
635 ecp_nistz256_scatter_w5 (row, &temp[1], 2);
636 ecp_nistz256_point_add (&temp[2], &temp[1], &temp[0]); /*2+1=3 */
637 ecp_nistz256_scatter_w5 (row, &temp[2], 3);
638 ecp_nistz256_point_double(&temp[1], &temp[1]); /*2*2=4 */
639 ecp_nistz256_scatter_w5 (row, &temp[1], 4);
640 ecp_nistz256_point_double(&temp[2], &temp[2]); /*2*3=6 */
641 ecp_nistz256_scatter_w5 (row, &temp[2], 6);
642 ecp_nistz256_point_add (&temp[3], &temp[1], &temp[0]); /*4+1=5 */
643 ecp_nistz256_scatter_w5 (row, &temp[3], 5);
644 ecp_nistz256_point_add (&temp[4], &temp[2], &temp[0]); /*6+1=7 */
645 ecp_nistz256_scatter_w5 (row, &temp[4], 7);
646 ecp_nistz256_point_double(&temp[1], &temp[1]); /*2*4=8 */
647 ecp_nistz256_scatter_w5 (row, &temp[1], 8);
648 ecp_nistz256_point_double(&temp[2], &temp[2]); /*2*6=12 */
649 ecp_nistz256_scatter_w5 (row, &temp[2], 12);
650 ecp_nistz256_point_double(&temp[3], &temp[3]); /*2*5=10 */
651 ecp_nistz256_scatter_w5 (row, &temp[3], 10);
652 ecp_nistz256_point_double(&temp[4], &temp[4]); /*2*7=14 */
653 ecp_nistz256_scatter_w5 (row, &temp[4], 14);
654 ecp_nistz256_point_add (&temp[2], &temp[2], &temp[0]); /*12+1=13*/
655 ecp_nistz256_scatter_w5 (row, &temp[2], 13);
656 ecp_nistz256_point_add (&temp[3], &temp[3], &temp[0]); /*10+1=11*/
657 ecp_nistz256_scatter_w5 (row, &temp[3], 11);
658 ecp_nistz256_point_add (&temp[4], &temp[4], &temp[0]); /*14+1=15*/
659 ecp_nistz256_scatter_w5 (row, &temp[4], 15);
660 ecp_nistz256_point_add (&temp[2], &temp[1], &temp[0]); /*8+1=9 */
661 ecp_nistz256_scatter_w5 (row, &temp[2], 9);
662 ecp_nistz256_point_double(&temp[1], &temp[1]); /*2*8=16 */
663 ecp_nistz256_scatter_w5 (row, &temp[1], 16);
4d3fa06f
AP		 664 }
665
49b05c7d 666 idx = 255;
4d3fa06f 667
49b05c7d
RS		 668 wvalue = p_str[0][(idx - 1) / 8];
669 wvalue = (wvalue >> ((idx - 1) % 8)) & mask;
4d3fa06f 670
3ff08e1d
AP		 671 /*
672 * We gather to temp[0], because we know it's position relative
673 * to table
674 */
675 ecp_nistz256_gather_w5(&temp[0], table[0], _booth_recode_w5(wvalue) >> 1);
676 memcpy(r, &temp[0], sizeof(temp[0]));
4d3fa06f 677
49b05c7d
RS		 678 while (idx >= 5) {
679 for (i = (idx == 255 ? 1 : 0); i < num; i++) {
680 unsigned int off = (idx - 1) / 8;
4d3fa06f
AP		 681
682 wvalue = p_str[i][off] | p_str[i][off + 1] << 8;
49b05c7d 683 wvalue = (wvalue >> ((idx - 1) % 8)) & mask;
4d3fa06f
AP		 684
685 wvalue = _booth_recode_w5(wvalue);
686
3ff08e1d 687 ecp_nistz256_gather_w5(&temp[0], table[i], wvalue >> 1);
4d3fa06f 688
3ff08e1d
AP		 689 ecp_nistz256_neg(temp[1].Y, temp[0].Y);
690 copy_conditional(temp[0].Y, temp[1].Y, (wvalue & 1));
4d3fa06f 691
3ff08e1d 692 ecp_nistz256_point_add(r, r, &temp[0]);
4d3fa06f
AP		 693 }
694
49b05c7d 695 idx -= window_size;
4d3fa06f
AP		 696
697 ecp_nistz256_point_double(r, r);
698 ecp_nistz256_point_double(r, r);
699 ecp_nistz256_point_double(r, r);
700 ecp_nistz256_point_double(r, r);
701 ecp_nistz256_point_double(r, r);
702 }
703
704 /* Final window */
705 for (i = 0; i < num; i++) {
706 wvalue = p_str[i][0];
707 wvalue = (wvalue << 1) & mask;
708
709 wvalue = _booth_recode_w5(wvalue);
710
3ff08e1d 711 ecp_nistz256_gather_w5(&temp[0], table[i], wvalue >> 1);
4d3fa06f 712
3ff08e1d
AP		 713 ecp_nistz256_neg(temp[1].Y, temp[0].Y);
714 copy_conditional(temp[0].Y, temp[1].Y, wvalue & 1);
4d3fa06f 715
3ff08e1d 716 ecp_nistz256_point_add(r, r, &temp[0]);
4d3fa06f
AP		 717 }
718
a4d5269e 719 ret = 1;
58d47cf0 720 err:
b548a1f1
RS		 721 OPENSSL_free(table_storage);
722 OPENSSL_free(p_str);
723 OPENSSL_free(scalars);
a4d5269e 724 return ret;
4d3fa06f
AP		 725}
726
727/* Coordinates of G, for which we have precomputed tables */
728const static BN_ULONG def_xG[P256_LIMBS] = {
729 TOBN(0x79e730d4, 0x18a9143c), TOBN(0x75ba95fc, 0x5fedb601),
730 TOBN(0x79fb732b, 0x77622510), TOBN(0x18905f76, 0xa53755c6)
731};
732
733const static BN_ULONG def_yG[P256_LIMBS] = {
734 TOBN(0xddf25357, 0xce95560a), TOBN(0x8b4ab8e4, 0xba19e45c),
735 TOBN(0xd2e88688, 0xdd21f325), TOBN(0x8571ff18, 0x25885d85)
736};
737
20728adc
AP		 738/*
739 * ecp_nistz256_is_affine_G returns one if |generator| is the standard, P-256
740 * generator.
741 */
58d47cf0 742static int ecp_nistz256_is_affine_G(const EC_POINT *generator)
4d3fa06f 743{
5784a521
MC		 744 return (bn_get_top(generator->X) == P256_LIMBS) &&
745 (bn_get_top(generator->Y) == P256_LIMBS) &&
746 (bn_get_top(generator->Z) == (P256_LIMBS - P256_LIMBS / 8)) &&
747 is_equal(bn_get_words(generator->X), def_xG) &&
748 is_equal(bn_get_words(generator->Y), def_yG) &&
749 is_one(bn_get_words(generator->Z));
4d3fa06f
AP		 750}
751
5956b110 752__owur static int ecp_nistz256_mult_precompute(EC_GROUP *group, BN_CTX *ctx)
4d3fa06f 753{
20728adc
AP		 754 /*
755 * We precompute a table for a Booth encoded exponent (wNAF) based
4d3fa06f 756 * computation. Each table holds 64 values for safe access, with an
20728adc
AP		 757 * implicit value of infinity at index zero. We use window of size 7, and
758 * therefore require ceil(256/7) = 37 tables.
759 */
be2e334f 760 const BIGNUM *order;
4d3fa06f
AP		 761 EC_POINT *P = NULL, *T = NULL;
762 const EC_POINT *generator;
3aef36ff 763 NISTZ256_PRE_COMP *pre_comp;
53dd4ddf 764 BN_CTX *new_ctx = NULL;
4d3fa06f
AP		 765 int i, j, k, ret = 0;
766 size_t w;
767
768 PRECOMP256_ROW *preComputedTable = NULL;
769 unsigned char *precomp_storage = NULL;
770
3aef36ff 771 /* if there is an old NISTZ256_PRE_COMP object, throw it away */
2c52ac9b 772 EC_pre_comp_free(group);
4d3fa06f
AP		 773 generator = EC_GROUP_get0_generator(group);
774 if (generator == NULL) {
be07ae9b 775 ECerr(EC_F_ECP_NISTZ256_MULT_PRECOMPUTE, EC_R_UNDEFINED_GENERATOR);
4d3fa06f
AP		 776 return 0;
777 }
778
779 if (ecp_nistz256_is_affine_G(generator)) {
20728adc
AP		 780 /*
781 * No need to calculate tables for the standard generator because we
782 * have them statically.
783 */
4d3fa06f
AP		 784 return 1;
785 }
786
be07ae9b 787 if ((pre_comp = ecp_nistz256_pre_comp_new(group)) == NULL)
4d3fa06f
AP		 788 return 0;
789
790 if (ctx == NULL) {
53dd4ddf 791 ctx = new_ctx = BN_CTX_new();
4d3fa06f
AP		 792 if (ctx == NULL)
793 goto err;
794 }
795
796 BN_CTX_start(ctx);
4d3fa06f 797
be2e334f 798 order = EC_GROUP_get0_order(group);
4d3fa06f
AP		 799 if (order == NULL)
800 goto err;
801
4d3fa06f 802 if (BN_is_zero(order)) {
be07ae9b 803 ECerr(EC_F_ECP_NISTZ256_MULT_PRECOMPUTE, EC_R_UNKNOWN_ORDER);
4d3fa06f
AP		 804 goto err;
805 }
806
807 w = 7;
808
809 if ((precomp_storage =
810 OPENSSL_malloc(37 * 64 * sizeof(P256_POINT_AFFINE) + 64)) == NULL) {
be07ae9b 811 ECerr(EC_F_ECP_NISTZ256_MULT_PRECOMPUTE, ERR_R_MALLOC_FAILURE);
4d3fa06f 812 goto err;
4d3fa06f
AP		 813 }
814
3ff08e1d
AP		 815 preComputedTable = (void *)ALIGNPTR(precomp_storage, 64);
816
4d3fa06f
AP		 817 P = EC_POINT_new(group);
818 T = EC_POINT_new(group);
53dd4ddf
EK		 819 if (P == NULL || T == NULL)
820 goto err;
4d3fa06f 821
20728adc
AP		 822 /*
823 * The zero entry is implicitly infinity, and we skip it, storing other
824 * values with -1 offset.
825 */
53dd4ddf
EK		 826 if (!EC_POINT_copy(T, generator))
827 goto err;
4d3fa06f
AP		 828
829 for (k = 0; k < 64; k++) {
53dd4ddf
EK		 830 if (!EC_POINT_copy(P, T))
831 goto err;
4d3fa06f 832 for (j = 0; j < 37; j++) {
3ff08e1d 833 P256_POINT_AFFINE temp;
20728adc 834 /*
6038354c 835 * It would be faster to use EC_POINTs_make_affine and
20728adc
AP		 836 * make multiple points affine at the same time.
837 */
6038354c
EK		 838 if (!EC_POINT_make_affine(group, P, ctx))
839 goto err;
840 if (!ecp_nistz256_bignum_to_field_elem(temp.X, P->X) ||
841 !ecp_nistz256_bignum_to_field_elem(temp.Y, P->Y)) {
842 ECerr(EC_F_ECP_NISTZ256_MULT_PRECOMPUTE,
843 EC_R_COORDINATES_OUT_OF_RANGE);
844 goto err;
845 }
3ff08e1d 846 ecp_nistz256_scatter_w7(preComputedTable[j], &temp, k);
6038354c
EK		 847 for (i = 0; i < 7; i++) {
848 if (!EC_POINT_dbl(group, P, P, ctx))
849 goto err;
850 }
4d3fa06f 851 }
6038354c
EK		 852 if (!EC_POINT_add(group, T, T, generator, ctx))
853 goto err;
4d3fa06f
AP		 854 }
855
856 pre_comp->group = group;
857 pre_comp->w = w;
858 pre_comp->precomp = preComputedTable;
859 pre_comp->precomp_storage = precomp_storage;
4d3fa06f 860 precomp_storage = NULL;
3aef36ff 861 SETPRECOMP(group, nistz256, pre_comp);
4d3fa06f 862 pre_comp = NULL;
4d3fa06f
AP		 863 ret = 1;
864
58d47cf0 865 err:
4d3fa06f
AP		 866 if (ctx != NULL)
867 BN_CTX_end(ctx);
53dd4ddf
EK		 868 BN_CTX_free(new_ctx);
869
3aef36ff 870 EC_nistz256_pre_comp_free(pre_comp);
b548a1f1 871 OPENSSL_free(precomp_storage);
8fdc3734
RS		 872 EC_POINT_free(P);
873 EC_POINT_free(T);
4d3fa06f
AP		 874 return ret;
875}
876
877/*
878 * Note that by default ECP_NISTZ256_AVX2 is undefined. While it's great
879 * code processing 4 points in parallel, corresponding serial operation
880 * is several times slower, because it uses 29x29=58-bit multiplication
881 * as opposite to 64x64=128-bit in integer-only scalar case. As result
882 * it doesn't provide *significant* performance improvement. Note that
883 * just defining ECP_NISTZ256_AVX2 is not sufficient to make it work,
884 * you'd need to compile even asm/ecp_nistz256-avx.pl module.
885 */
886#if defined(ECP_NISTZ256_AVX2)
3ff08e1d 887# if !(defined(__x86_64) || defined(__x86_64__) || \
4d3fa06f
AP		 888 defined(_M_AMD64) || defined(_MX64)) || \
889 !(defined(__GNUC__) || defined(_MSC_VER)) /* this is for ALIGN32 */
890# undef ECP_NISTZ256_AVX2
891# else
892/* Constant time access, loading four values, from four consecutive tables */
58d47cf0
AP		 893void ecp_nistz256_avx2_multi_gather_w7(void *result, const void *in,
894 int index0, int index1, int index2,
895 int index3);
4d3fa06f
AP		 896void ecp_nistz256_avx2_transpose_convert(void *RESULTx4, const void *in);
897void ecp_nistz256_avx2_convert_transpose_back(void *result, const void *Ax4);
898void ecp_nistz256_avx2_point_add_affine_x4(void *RESULTx4, const void *Ax4,
899 const void *Bx4);
900void ecp_nistz256_avx2_point_add_affines_x4(void *RESULTx4, const void *Ax4,
901 const void *Bx4);
902void ecp_nistz256_avx2_to_mont(void *RESULTx4, const void *Ax4);
903void ecp_nistz256_avx2_from_mont(void *RESULTx4, const void *Ax4);
904void ecp_nistz256_avx2_set1(void *RESULTx4);
905int ecp_nistz_avx2_eligible(void);
906
907static void booth_recode_w7(unsigned char *sign,
908 unsigned char *digit, unsigned char in)
909{
910 unsigned char s, d;
911
912 s = ~((in >> 7) - 1);
913 d = (1 << 8) - in - 1;
914 d = (d & s) | (in & ~s);
915 d = (d >> 1) + (d & 1);
916
917 *sign = s & 1;
918 *digit = d;
919}
920
20728adc
AP		 921/*
922 * ecp_nistz256_avx2_mul_g performs multiplication by G, using only the
4d3fa06f 923 * precomputed table. It does 4 affine point additions in parallel,
20728adc
AP		 924 * significantly speeding up point multiplication for a fixed value.
925 */
58d47cf0 926static void ecp_nistz256_avx2_mul_g(P256_POINT *r,
4d3fa06f 927 unsigned char p_str[33],
58d47cf0 928 const P256_POINT_AFFINE(*preComputedTable)[64])
4d3fa06f
AP		 929{
930 const unsigned int window_size = 7;
931 const unsigned int mask = (1 << (window_size + 1)) - 1;
932 unsigned int wvalue;
933 /* Using 4 windows at a time */
934 unsigned char sign0, digit0;
935 unsigned char sign1, digit1;
936 unsigned char sign2, digit2;
937 unsigned char sign3, digit3;
49b05c7d 938 unsigned int idx = 0;
4d3fa06f
AP		 939 BN_ULONG tmp[P256_LIMBS];
940 int i;
941
942 ALIGN32 BN_ULONG aX4[4 * 9 * 3] = { 0 };
943 ALIGN32 BN_ULONG bX4[4 * 9 * 2] = { 0 };
3ff08e1d
AP		 944 ALIGN32 P256_POINT_AFFINE point_arr[4];
945 ALIGN32 P256_POINT res_point_arr[4];
4d3fa06f
AP		 946
947 /* Initial four windows */
948 wvalue = *((u16 *) & p_str[0]);
949 wvalue = (wvalue << 1) & mask;
49b05c7d 950 idx += window_size;
4d3fa06f 951 booth_recode_w7(&sign0, &digit0, wvalue);
49b05c7d
RS		 952 wvalue = *((u16 *) & p_str[(idx - 1) / 8]);
953 wvalue = (wvalue >> ((idx - 1) % 8)) & mask;
954 idx += window_size;
4d3fa06f 955 booth_recode_w7(&sign1, &digit1, wvalue);
49b05c7d
RS		 956 wvalue = *((u16 *) & p_str[(idx - 1) / 8]);
957 wvalue = (wvalue >> ((idx - 1) % 8)) & mask;
958 idx += window_size;
4d3fa06f 959 booth_recode_w7(&sign2, &digit2, wvalue);
49b05c7d
RS		 960 wvalue = *((u16 *) & p_str[(idx - 1) / 8]);
961 wvalue = (wvalue >> ((idx - 1) % 8)) & mask;
962 idx += window_size;
4d3fa06f
AP		 963 booth_recode_w7(&sign3, &digit3, wvalue);
964
3ff08e1d 965 ecp_nistz256_avx2_multi_gather_w7(point_arr, preComputedTable[0],
4d3fa06f
AP		 966 digit0, digit1, digit2, digit3);
967
968 ecp_nistz256_neg(tmp, point_arr[0].Y);
969 copy_conditional(point_arr[0].Y, tmp, sign0);
970 ecp_nistz256_neg(tmp, point_arr[1].Y);
971 copy_conditional(point_arr[1].Y, tmp, sign1);
972 ecp_nistz256_neg(tmp, point_arr[2].Y);
973 copy_conditional(point_arr[2].Y, tmp, sign2);
974 ecp_nistz256_neg(tmp, point_arr[3].Y);
975 copy_conditional(point_arr[3].Y, tmp, sign3);
976
977 ecp_nistz256_avx2_transpose_convert(aX4, point_arr);
978 ecp_nistz256_avx2_to_mont(aX4, aX4);
979 ecp_nistz256_avx2_to_mont(&aX4[4 * 9], &aX4[4 * 9]);
980 ecp_nistz256_avx2_set1(&aX4[4 * 9 * 2]);
981
49b05c7d
RS		 982 wvalue = *((u16 *) & p_str[(idx - 1) / 8]);
983 wvalue = (wvalue >> ((idx - 1) % 8)) & mask;
984 idx += window_size;
4d3fa06f 985 booth_recode_w7(&sign0, &digit0, wvalue);
49b05c7d
RS		 986 wvalue = *((u16 *) & p_str[(idx - 1) / 8]);
987 wvalue = (wvalue >> ((idx - 1) % 8)) & mask;
988 idx += window_size;
4d3fa06f 989 booth_recode_w7(&sign1, &digit1, wvalue);
49b05c7d
RS		 990 wvalue = *((u16 *) & p_str[(idx - 1) / 8]);
991 wvalue = (wvalue >> ((idx - 1) % 8)) & mask;
992 idx += window_size;
4d3fa06f 993 booth_recode_w7(&sign2, &digit2, wvalue);
49b05c7d
RS		 994 wvalue = *((u16 *) & p_str[(idx - 1) / 8]);
995 wvalue = (wvalue >> ((idx - 1) % 8)) & mask;
996 idx += window_size;
4d3fa06f
AP		 997 booth_recode_w7(&sign3, &digit3, wvalue);
998
3ff08e1d 999 ecp_nistz256_avx2_multi_gather_w7(point_arr, preComputedTable[4 * 1],
4d3fa06f
AP		 1000 digit0, digit1, digit2, digit3);
1001
1002 ecp_nistz256_neg(tmp, point_arr[0].Y);
1003 copy_conditional(point_arr[0].Y, tmp, sign0);
1004 ecp_nistz256_neg(tmp, point_arr[1].Y);
1005 copy_conditional(point_arr[1].Y, tmp, sign1);
1006 ecp_nistz256_neg(tmp, point_arr[2].Y);
1007 copy_conditional(point_arr[2].Y, tmp, sign2);
1008 ecp_nistz256_neg(tmp, point_arr[3].Y);
1009 copy_conditional(point_arr[3].Y, tmp, sign3);
1010
1011 ecp_nistz256_avx2_transpose_convert(bX4, point_arr);
1012 ecp_nistz256_avx2_to_mont(bX4, bX4);
1013 ecp_nistz256_avx2_to_mont(&bX4[4 * 9], &bX4[4 * 9]);
1014 /* Optimized when both inputs are affine */
1015 ecp_nistz256_avx2_point_add_affines_x4(aX4, aX4, bX4);
1016
1017 for (i = 2; i < 9; i++) {
49b05c7d
RS		 1018 wvalue = *((u16 *) & p_str[(idx - 1) / 8]);
1019 wvalue = (wvalue >> ((idx - 1) % 8)) & mask;
1020 idx += window_size;
4d3fa06f 1021 booth_recode_w7(&sign0, &digit0, wvalue);
49b05c7d
RS		 1022 wvalue = *((u16 *) & p_str[(idx - 1) / 8]);
1023 wvalue = (wvalue >> ((idx - 1) % 8)) & mask;
1024 idx += window_size;
4d3fa06f 1025 booth_recode_w7(&sign1, &digit1, wvalue);
49b05c7d
RS		 1026 wvalue = *((u16 *) & p_str[(idx - 1) / 8]);
1027 wvalue = (wvalue >> ((idx - 1) % 8)) & mask;
1028 idx += window_size;
4d3fa06f 1029 booth_recode_w7(&sign2, &digit2, wvalue);
49b05c7d
RS		 1030 wvalue = *((u16 *) & p_str[(idx - 1) / 8]);
1031 wvalue = (wvalue >> ((idx - 1) % 8)) & mask;
1032 idx += window_size;
4d3fa06f
AP		 1033 booth_recode_w7(&sign3, &digit3, wvalue);
1034
3ff08e1d 1035 ecp_nistz256_avx2_multi_gather_w7(point_arr,
4d3fa06f
AP		 1036 preComputedTable[4 * i],
1037 digit0, digit1, digit2, digit3);
1038
1039 ecp_nistz256_neg(tmp, point_arr[0].Y);
1040 copy_conditional(point_arr[0].Y, tmp, sign0);
1041 ecp_nistz256_neg(tmp, point_arr[1].Y);
1042 copy_conditional(point_arr[1].Y, tmp, sign1);
1043 ecp_nistz256_neg(tmp, point_arr[2].Y);
1044 copy_conditional(point_arr[2].Y, tmp, sign2);
1045 ecp_nistz256_neg(tmp, point_arr[3].Y);
1046 copy_conditional(point_arr[3].Y, tmp, sign3);
1047
1048 ecp_nistz256_avx2_transpose_convert(bX4, point_arr);
1049 ecp_nistz256_avx2_to_mont(bX4, bX4);
1050 ecp_nistz256_avx2_to_mont(&bX4[4 * 9], &bX4[4 * 9]);
1051
1052 ecp_nistz256_avx2_point_add_affine_x4(aX4, aX4, bX4);
1053 }
1054
1055 ecp_nistz256_avx2_from_mont(&aX4[4 * 9 * 0], &aX4[4 * 9 * 0]);
1056 ecp_nistz256_avx2_from_mont(&aX4[4 * 9 * 1], &aX4[4 * 9 * 1]);
1057 ecp_nistz256_avx2_from_mont(&aX4[4 * 9 * 2], &aX4[4 * 9 * 2]);
1058
1059 ecp_nistz256_avx2_convert_transpose_back(res_point_arr, aX4);
1060 /* Last window is performed serially */
49b05c7d
RS		 1061 wvalue = *((u16 *) & p_str[(idx - 1) / 8]);
1062 wvalue = (wvalue >> ((idx - 1) % 8)) & mask;
4d3fa06f 1063 booth_recode_w7(&sign0, &digit0, wvalue);
58d47cf0
AP		 1064 ecp_nistz256_gather_w7((P256_POINT_AFFINE *)r,
1065 preComputedTable[36], digit0);
4d3fa06f
AP		 1066 ecp_nistz256_neg(tmp, r->Y);
1067 copy_conditional(r->Y, tmp, sign0);
1068 memcpy(r->Z, ONE, sizeof(ONE));
1069 /* Sum the four windows */
1070 ecp_nistz256_point_add(r, r, &res_point_arr[0]);
1071 ecp_nistz256_point_add(r, r, &res_point_arr[1]);
1072 ecp_nistz256_point_add(r, r, &res_point_arr[2]);
1073 ecp_nistz256_point_add(r, r, &res_point_arr[3]);
1074}
1075# endif
1076#endif
1077
5956b110
EK		 1078__owur static int ecp_nistz256_set_from_affine(EC_POINT *out, const EC_GROUP *group,
1079 const P256_POINT_AFFINE *in,
1080 BN_CTX *ctx)
4d3fa06f 1081{
5784a521 1082 BIGNUM *x, *y;
4d3fa06f
AP		 1083 BN_ULONG d_x[P256_LIMBS], d_y[P256_LIMBS];
1084 int ret = 0;
1085
5784a521 1086 x = BN_new();
90945fa3 1087 if (x == NULL)
5784a521
MC		 1088 return 0;
1089 y = BN_new();
90945fa3 1090 if (y == NULL) {
5784a521
MC		 1091 BN_free(x);
1092 return 0;
1093 }
4d3fa06f 1094 memcpy(d_x, in->X, sizeof(d_x));
5784a521 1095 bn_set_static_words(x, d_x, P256_LIMBS);
4d3fa06f
AP		 1096
1097 memcpy(d_y, in->Y, sizeof(d_y));
5784a521
MC		 1098 bn_set_static_words(y, d_y, P256_LIMBS);
1099
1100 ret = EC_POINT_set_affine_coordinates_GFp(group, out, x, y, ctx);
4d3fa06f 1101
23a1d5e9
RS		 1102 BN_free(x);
1103 BN_free(y);
4d3fa06f
AP		 1104
1105 return ret;
1106}
1107
1108/* r = scalar*G + sum(scalars[i]*points[i]) */
5956b110
EK		 1109__owur static int ecp_nistz256_points_mul(const EC_GROUP *group,
1110 EC_POINT *r,
1111 const BIGNUM *scalar,
1112 size_t num,
1113 const EC_POINT *points[],
1114 const BIGNUM *scalars[], BN_CTX *ctx)
4d3fa06f
AP		 1115{
1116 int i = 0, ret = 0, no_precomp_for_generator = 0, p_is_infinity = 0;
16e5b45f 1117 size_t j;
4d3fa06f
AP		 1118 unsigned char p_str[33] = { 0 };
1119 const PRECOMP256_ROW *preComputedTable = NULL;
3aef36ff 1120 const NISTZ256_PRE_COMP *pre_comp = NULL;
4d3fa06f 1121 const EC_POINT *generator = NULL;
e22d2199 1122 BN_CTX *new_ctx = NULL;
a4d5269e
EK		 1123 const BIGNUM **new_scalars = NULL;
1124 const EC_POINT **new_points = NULL;
49b05c7d 1125 unsigned int idx = 0;
4d3fa06f
AP		 1126 const unsigned int window_size = 7;
1127 const unsigned int mask = (1 << (window_size + 1)) - 1;
1128 unsigned int wvalue;
1129 ALIGN32 union {
1130 P256_POINT p;
1131 P256_POINT_AFFINE a;
1132 } t, p;
1133 BIGNUM *tmp_scalar;
1134
58d47cf0 1135 if ((num + 1) == 0 || (num + 1) > OPENSSL_MALLOC_MAX_NELEMS(void *)) {
3ff08e1d
AP		 1136 ECerr(EC_F_ECP_NISTZ256_POINTS_MUL, ERR_R_MALLOC_FAILURE);
1137 return 0;
1138 }
1139
4d3fa06f 1140 if (group->meth != r->meth) {
be07ae9b 1141 ECerr(EC_F_ECP_NISTZ256_POINTS_MUL, EC_R_INCOMPATIBLE_OBJECTS);
4d3fa06f
AP		 1142 return 0;
1143 }
e22d2199 1144
4d3fa06f
AP		 1145 if ((scalar == NULL) && (num == 0))
1146 return EC_POINT_set_to_infinity(group, r);
1147
16e5b45f
DSH		 1148 for (j = 0; j < num; j++) {
1149 if (group->meth != points[j]->meth) {
be07ae9b 1150 ECerr(EC_F_ECP_NISTZ256_POINTS_MUL, EC_R_INCOMPATIBLE_OBJECTS);
4d3fa06f
AP		 1151 return 0;
1152 }
1153 }
1154
e22d2199
EK		 1155 if (ctx == NULL) {
1156 ctx = new_ctx = BN_CTX_new();
1157 if (ctx == NULL)
1158 goto err;
1159 }
1160
1161 BN_CTX_start(ctx);
4d3fa06f
AP		 1162
1163 if (scalar) {
1164 generator = EC_GROUP_get0_generator(group);
1165 if (generator == NULL) {
be07ae9b 1166 ECerr(EC_F_ECP_NISTZ256_POINTS_MUL, EC_R_UNDEFINED_GENERATOR);
4d3fa06f
AP		 1167 goto err;
1168 }
1169
1170 /* look if we can use precomputed multiples of generator */
3aef36ff 1171 pre_comp = group->pre_comp.nistz256;
4d3fa06f
AP		 1172
1173 if (pre_comp) {
20728adc
AP		 1174 /*
1175 * If there is a precomputed table for the generator, check that
1176 * it was generated with the same generator.
1177 */
4d3fa06f
AP		 1178 EC_POINT *pre_comp_generator = EC_POINT_new(group);
1179 if (pre_comp_generator == NULL)
1180 goto err;
1181
3ff08e1d
AP		 1182 if (!ecp_nistz256_set_from_affine(pre_comp_generator,
1183 group, pre_comp->precomp[0],
e22d2199
EK		 1184 ctx)) {
1185 EC_POINT_free(pre_comp_generator);
4d3fa06f 1186 goto err;
e22d2199 1187 }
4d3fa06f
AP		 1188
1189 if (0 == EC_POINT_cmp(group, generator, pre_comp_generator, ctx))
1190 preComputedTable = (const PRECOMP256_ROW *)pre_comp->precomp;
1191
1192 EC_POINT_free(pre_comp_generator);
1193 }
1194
1195 if (preComputedTable == NULL && ecp_nistz256_is_affine_G(generator)) {
20728adc
AP		 1196 /*
1197 * If there is no precomputed data, but the generator is the
1198 * default, a hardcoded table of precomputed data is used. This
1199 * is because applications, such as Apache, do not use
1200 * EC_KEY_precompute_mult.
1201 */
3ff08e1d 1202 preComputedTable = ecp_nistz256_precomputed;
4d3fa06f
AP		 1203 }
1204
1205 if (preComputedTable) {
1206 if ((BN_num_bits(scalar) > 256)
1207 || BN_is_negative(scalar)) {
1208 if ((tmp_scalar = BN_CTX_get(ctx)) == NULL)
1209 goto err;
1210
5784a521 1211 if (!BN_nnmod(tmp_scalar, scalar, group->order, ctx)) {
be07ae9b 1212 ECerr(EC_F_ECP_NISTZ256_POINTS_MUL, ERR_R_BN_LIB);
4d3fa06f
AP		 1213 goto err;
1214 }
1215 scalar = tmp_scalar;
1216 }
1217
5784a521
MC		 1218 for (i = 0; i < bn_get_top(scalar) * BN_BYTES; i += BN_BYTES) {
1219 BN_ULONG d = bn_get_words(scalar)[i / BN_BYTES];
4d3fa06f 1220
5afc296a
AP		 1221 p_str[i + 0] = (unsigned char)d;
1222 p_str[i + 1] = (unsigned char)(d >> 8);
1223 p_str[i + 2] = (unsigned char)(d >> 16);
1224 p_str[i + 3] = (unsigned char)(d >>= 24);
4d3fa06f
AP		 1225 if (BN_BYTES == 8) {
1226 d >>= 8;
5afc296a
AP		 1227 p_str[i + 4] = (unsigned char)d;
1228 p_str[i + 5] = (unsigned char)(d >> 8);
1229 p_str[i + 6] = (unsigned char)(d >> 16);
1230 p_str[i + 7] = (unsigned char)(d >> 24);
4d3fa06f
AP		 1231 }
1232 }
1233
1234 for (; i < 33; i++)
1235 p_str[i] = 0;
1236
1237#if defined(ECP_NISTZ256_AVX2)
1238 if (ecp_nistz_avx2_eligible()) {
1239 ecp_nistz256_avx2_mul_g(&p.p, p_str, preComputedTable);
1240 } else
1241#endif
1242 {
1243 /* First window */
1244 wvalue = (p_str[0] << 1) & mask;
49b05c7d 1245 idx += window_size;
4d3fa06f
AP		 1246
1247 wvalue = _booth_recode_w7(wvalue);
1248
58d47cf0
AP		 1249 ecp_nistz256_gather_w7(&p.a, preComputedTable[0],
1250 wvalue >> 1);
4d3fa06f
AP		 1251
1252 ecp_nistz256_neg(p.p.Z, p.p.Y);
1253 copy_conditional(p.p.Y, p.p.Z, wvalue & 1);
1254
1255 memcpy(p.p.Z, ONE, sizeof(ONE));
1256
1257 for (i = 1; i < 37; i++) {
49b05c7d 1258 unsigned int off = (idx - 1) / 8;
4d3fa06f 1259 wvalue = p_str[off] | p_str[off + 1] << 8;
49b05c7d
RS		 1260 wvalue = (wvalue >> ((idx - 1) % 8)) & mask;
1261 idx += window_size;
4d3fa06f
AP		 1262
1263 wvalue = _booth_recode_w7(wvalue);
1264
3ff08e1d 1265 ecp_nistz256_gather_w7(&t.a,
4d3fa06f
AP		 1266 preComputedTable[i], wvalue >> 1);
1267
1268 ecp_nistz256_neg(t.p.Z, t.a.Y);
1269 copy_conditional(t.a.Y, t.p.Z, wvalue & 1);
1270
1271 ecp_nistz256_point_add_affine(&p.p, &p.p, &t.a);
1272 }
1273 }
1274 } else {
1275 p_is_infinity = 1;
1276 no_precomp_for_generator = 1;
1277 }
1278 } else
1279 p_is_infinity = 1;
1280
1281 if (no_precomp_for_generator) {
20728adc
AP		 1282 /*
1283 * Without a precomputed table for the generator, it has to be
1284 * handled like a normal point.
1285 */
4d3fa06f 1286 new_scalars = OPENSSL_malloc((num + 1) * sizeof(BIGNUM *));
90945fa3 1287 if (new_scalars == NULL) {
be07ae9b 1288 ECerr(EC_F_ECP_NISTZ256_POINTS_MUL, ERR_R_MALLOC_FAILURE);
e22d2199 1289 goto err;
4d3fa06f
AP		 1290 }
1291
1292 new_points = OPENSSL_malloc((num + 1) * sizeof(EC_POINT *));
90945fa3 1293 if (new_points == NULL) {
be07ae9b 1294 ECerr(EC_F_ECP_NISTZ256_POINTS_MUL, ERR_R_MALLOC_FAILURE);
e22d2199 1295 goto err;
4d3fa06f
AP		 1296 }
1297
1298 memcpy(new_scalars, scalars, num * sizeof(BIGNUM *));
1299 new_scalars[num] = scalar;
1300 memcpy(new_points, points, num * sizeof(EC_POINT *));
1301 new_points[num] = generator;
1302
1303 scalars = new_scalars;
1304 points = new_points;
1305 num++;
1306 }
1307
1308 if (num) {
1309 P256_POINT *out = &t.p;
1310 if (p_is_infinity)
1311 out = &p.p;
1312
a4d5269e
EK		 1313 if (!ecp_nistz256_windowed_mul(group, out, scalars, points, num, ctx))
1314 goto err;
4d3fa06f
AP		 1315
1316 if (!p_is_infinity)
1317 ecp_nistz256_point_add(&p.p, &p.p, out);
1318 }
1319
c028254b 1320 /* Not constant-time, but we're only operating on the public output. */
e22d2199
EK		 1321 if (!bn_set_words(r->X, p.p.X, P256_LIMBS) ||
1322 !bn_set_words(r->Y, p.p.Y, P256_LIMBS) ||
1323 !bn_set_words(r->Z, p.p.Z, P256_LIMBS)) {
1324 goto err;
1325 }
4446044a 1326 r->Z_is_one = is_one(p.p.Z) & 1;
4d3fa06f
AP		 1327
1328 ret = 1;
1329
e22d2199
EK		 1330err:
1331 if (ctx)
1332 BN_CTX_end(ctx);
1333 BN_CTX_free(new_ctx);
b548a1f1
RS		 1334 OPENSSL_free(new_points);
1335 OPENSSL_free(new_scalars);
4d3fa06f
AP		 1336 return ret;
1337}
1338
5956b110
EK		 1339__owur static int ecp_nistz256_get_affine(const EC_GROUP *group,
1340 const EC_POINT *point,
1341 BIGNUM *x, BIGNUM *y, BN_CTX *ctx)
4d3fa06f
AP		 1342{
1343 BN_ULONG z_inv2[P256_LIMBS];
1344 BN_ULONG z_inv3[P256_LIMBS];
1345 BN_ULONG x_aff[P256_LIMBS];
1346 BN_ULONG y_aff[P256_LIMBS];
1347 BN_ULONG point_x[P256_LIMBS], point_y[P256_LIMBS], point_z[P256_LIMBS];
e22d2199 1348 BN_ULONG x_ret[P256_LIMBS], y_ret[P256_LIMBS];
4d3fa06f
AP		 1349
1350 if (EC_POINT_is_at_infinity(group, point)) {
be07ae9b 1351 ECerr(EC_F_ECP_NISTZ256_GET_AFFINE, EC_R_POINT_AT_INFINITY);
4d3fa06f
AP		 1352 return 0;
1353 }
1354
5784a521
MC		 1355 if (!ecp_nistz256_bignum_to_field_elem(point_x, point->X) ||
1356 !ecp_nistz256_bignum_to_field_elem(point_y, point->Y) ||
1357 !ecp_nistz256_bignum_to_field_elem(point_z, point->Z)) {
be07ae9b 1358 ECerr(EC_F_ECP_NISTZ256_GET_AFFINE, EC_R_COORDINATES_OUT_OF_RANGE);
4d3fa06f
AP		 1359 return 0;
1360 }
1361
1362 ecp_nistz256_mod_inverse(z_inv3, point_z);
1363 ecp_nistz256_sqr_mont(z_inv2, z_inv3);
1364 ecp_nistz256_mul_mont(x_aff, z_inv2, point_x);
1365
1366 if (x != NULL) {
e22d2199
EK		 1367 ecp_nistz256_from_mont(x_ret, x_aff);
1368 if (!bn_set_words(x, x_ret, P256_LIMBS))
1369 return 0;
4d3fa06f
AP		 1370 }
1371
1372 if (y != NULL) {
1373 ecp_nistz256_mul_mont(z_inv3, z_inv3, z_inv2);
1374 ecp_nistz256_mul_mont(y_aff, z_inv3, point_y);
e22d2199
EK		 1375 ecp_nistz256_from_mont(y_ret, y_aff);
1376 if (!bn_set_words(y, y_ret, P256_LIMBS))
1377 return 0;
4d3fa06f
AP		 1378 }
1379
1380 return 1;
1381}
1382
3aef36ff 1383static NISTZ256_PRE_COMP *ecp_nistz256_pre_comp_new(const EC_GROUP *group)
4d3fa06f 1384{
3aef36ff 1385 NISTZ256_PRE_COMP *ret = NULL;
4d3fa06f
AP		 1386
1387 if (!group)
1388 return NULL;
1389
3aef36ff 1390 ret = OPENSSL_zalloc(sizeof(*ret));
4d3fa06f 1391
90945fa3 1392 if (ret == NULL) {
be07ae9b 1393 ECerr(EC_F_ECP_NISTZ256_PRE_COMP_NEW, ERR_R_MALLOC_FAILURE);
4d3fa06f
AP		 1394 return ret;
1395 }
1396
1397 ret->group = group;
1398 ret->w = 6; /* default */
4d3fa06f 1399 ret->references = 1;
9b398ef2
AG		 1400
1401 ret->lock = CRYPTO_THREAD_lock_new();
1402 if (ret->lock == NULL) {
1403 ECerr(EC_F_ECP_NISTZ256_PRE_COMP_NEW, ERR_R_MALLOC_FAILURE);
1404 OPENSSL_free(ret);
1405 return NULL;
1406 }
4d3fa06f
AP		 1407 return ret;
1408}
1409
3aef36ff 1410NISTZ256_PRE_COMP *EC_nistz256_pre_comp_dup(NISTZ256_PRE_COMP *p)
4d3fa06f 1411{
9b398ef2 1412 int i;
3aef36ff 1413 if (p != NULL)
9b398ef2 1414 CRYPTO_atomic_add(&p->references, 1, &i, p->lock);
3aef36ff 1415 return p;
4d3fa06f
AP		 1416}
1417
3aef36ff 1418void EC_nistz256_pre_comp_free(NISTZ256_PRE_COMP *pre)
4d3fa06f 1419{
9b398ef2
AG		 1420 int i;
1421
1422 if (pre == NULL)
4d3fa06f 1423 return;
9b398ef2
AG		 1424
1425 CRYPTO_atomic_add(&pre->references, -1, &i, pre->lock);
1426 REF_PRINT_COUNT("EC_nistz256", x);
1427 if (i > 0)
1428 return;
1429 REF_ASSERT_ISNT(i < 0);
1430
b548a1f1 1431 OPENSSL_free(pre->precomp_storage);
9b398ef2 1432 CRYPTO_THREAD_lock_free(pre->lock);
4d3fa06f
AP		 1433 OPENSSL_free(pre);
1434}
1435
4d3fa06f 1436
58d47cf0 1437static int ecp_nistz256_window_have_precompute_mult(const EC_GROUP *group)
4d3fa06f
AP		 1438{
1439 /* There is a hard-coded table for the default generator. */
1440 const EC_POINT *generator = EC_GROUP_get0_generator(group);
3aef36ff 1441
4d3fa06f
AP		 1442 if (generator != NULL && ecp_nistz256_is_affine_G(generator)) {
1443 /* There is a hard-coded table for the default generator. */
1444 return 1;
1445 }
1446
3aef36ff 1447 return HAVEPRECOMP(group, nistz256);
4d3fa06f
AP		 1448}
1449
1450const EC_METHOD *EC_GFp_nistz256_method(void)
1451{
1452 static const EC_METHOD ret = {
1453 EC_FLAGS_DEFAULT_OCT,
1454 NID_X9_62_prime_field,
1455 ec_GFp_mont_group_init,
1456 ec_GFp_mont_group_finish,
1457 ec_GFp_mont_group_clear_finish,
1458 ec_GFp_mont_group_copy,
1459 ec_GFp_mont_group_set_curve,
1460 ec_GFp_simple_group_get_curve,
1461 ec_GFp_simple_group_get_degree,
9ff9bccc 1462 ec_group_simple_order_bits,
4d3fa06f
AP		 1463 ec_GFp_simple_group_check_discriminant,
1464 ec_GFp_simple_point_init,
1465 ec_GFp_simple_point_finish,
1466 ec_GFp_simple_point_clear_finish,
1467 ec_GFp_simple_point_copy,
1468 ec_GFp_simple_point_set_to_infinity,
1469 ec_GFp_simple_set_Jprojective_coordinates_GFp,
1470 ec_GFp_simple_get_Jprojective_coordinates_GFp,
1471 ec_GFp_simple_point_set_affine_coordinates,
1472 ecp_nistz256_get_affine,
1473 0, 0, 0,
1474 ec_GFp_simple_add,
1475 ec_GFp_simple_dbl,
1476 ec_GFp_simple_invert,
1477 ec_GFp_simple_is_at_infinity,
1478 ec_GFp_simple_is_on_curve,
1479 ec_GFp_simple_cmp,
1480 ec_GFp_simple_make_affine,
1481 ec_GFp_simple_points_make_affine,
1482 ecp_nistz256_points_mul, /* mul */
1483 ecp_nistz256_mult_precompute, /* precompute_mult */
1484 ecp_nistz256_window_have_precompute_mult, /* have_precompute_mult */
1485 ec_GFp_mont_field_mul,
1486 ec_GFp_mont_field_sqr,
1487 0, /* field_div */
1488 ec_GFp_mont_field_encode,
1489 ec_GFp_mont_field_decode,
9ff9bccc
DSH		 1490 ec_GFp_mont_field_set_to_one,
1491 ec_key_simple_priv2oct,
1492 ec_key_simple_oct2priv,
1493 0, /* set private */
1494 ec_key_simple_generate_key,
1495 ec_key_simple_check_key,
1496 ec_key_simple_generate_public_key,
1497 0, /* keycopy */
1498 0, /* keyfinish */
1499 ecdh_simple_compute_key
4d3fa06f
AP		 1500 };
1501
1502 return &ret;
1503}
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