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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 | |
52 | typedef unsigned short u16; | |
53 | ||
54 | typedef struct { | |
55 | BN_ULONG X[P256_LIMBS]; | |
56 | BN_ULONG Y[P256_LIMBS]; | |
57 | BN_ULONG Z[P256_LIMBS]; | |
58 | } P256_POINT; | |
59 | ||
60 | typedef struct { | |
61 | BN_ULONG X[P256_LIMBS]; | |
62 | BN_ULONG Y[P256_LIMBS]; | |
63 | } P256_POINT_AFFINE; | |
64 | ||
65 | typedef P256_POINT_AFFINE PRECOMP256_ROW[64]; | |
66 | ||
67 | /* structure for precomputed multiples of the generator */ | |
3aef36ff | 68 | struct 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; | |
3aef36ff | 79 | }; |
4d3fa06f AP |
80 | |
81 | /* Functions implemented in assembly */ | |
82 | /* Modular mul by 2: res = 2*a mod P */ | |
83 | void ecp_nistz256_mul_by_2(BN_ULONG res[P256_LIMBS], | |
84 | const BN_ULONG a[P256_LIMBS]); | |
85 | /* Modular div by 2: res = a/2 mod P */ | |
86 | void ecp_nistz256_div_by_2(BN_ULONG res[P256_LIMBS], | |
87 | const BN_ULONG a[P256_LIMBS]); | |
88 | /* Modular mul by 3: res = 3*a mod P */ | |
89 | void ecp_nistz256_mul_by_3(BN_ULONG res[P256_LIMBS], | |
90 | const BN_ULONG a[P256_LIMBS]); | |
20728adc | 91 | /* Modular add: res = a+b mod P */ |
4d3fa06f AP |
92 | void ecp_nistz256_add(BN_ULONG res[P256_LIMBS], |
93 | const BN_ULONG a[P256_LIMBS], | |
94 | const BN_ULONG b[P256_LIMBS]); | |
20728adc | 95 | /* Modular sub: res = a-b mod P */ |
4d3fa06f AP |
96 | void ecp_nistz256_sub(BN_ULONG res[P256_LIMBS], |
97 | const BN_ULONG a[P256_LIMBS], | |
98 | const BN_ULONG b[P256_LIMBS]); | |
20728adc | 99 | /* Modular neg: res = -a mod P */ |
4d3fa06f AP |
100 | void ecp_nistz256_neg(BN_ULONG res[P256_LIMBS], const BN_ULONG a[P256_LIMBS]); |
101 | /* Montgomery mul: res = a*b*2^-256 mod P */ | |
102 | void ecp_nistz256_mul_mont(BN_ULONG res[P256_LIMBS], | |
103 | const BN_ULONG a[P256_LIMBS], | |
104 | const BN_ULONG b[P256_LIMBS]); | |
105 | /* Montgomery sqr: res = a*a*2^-256 mod P */ | |
106 | void ecp_nistz256_sqr_mont(BN_ULONG res[P256_LIMBS], | |
107 | const BN_ULONG a[P256_LIMBS]); | |
108 | /* Convert a number from Montgomery domain, by multiplying with 1 */ | |
109 | void ecp_nistz256_from_mont(BN_ULONG res[P256_LIMBS], | |
110 | const BN_ULONG in[P256_LIMBS]); | |
111 | /* Convert a number to Montgomery domain, by multiplying with 2^512 mod P*/ | |
112 | void ecp_nistz256_to_mont(BN_ULONG res[P256_LIMBS], | |
113 | const BN_ULONG in[P256_LIMBS]); | |
114 | /* Functions that perform constant time access to the precomputed tables */ | |
58d47cf0 | 115 | void ecp_nistz256_scatter_w5(P256_POINT *val, |
49b05c7d | 116 | const P256_POINT *in_t, int idx); |
20728adc | 117 | void ecp_nistz256_gather_w5(P256_POINT *val, |
49b05c7d | 118 | const P256_POINT *in_t, int idx); |
58d47cf0 | 119 | void ecp_nistz256_scatter_w7(P256_POINT_AFFINE *val, |
49b05c7d | 120 | const P256_POINT_AFFINE *in_t, int idx); |
58d47cf0 | 121 | void ecp_nistz256_gather_w7(P256_POINT_AFFINE *val, |
49b05c7d | 122 | const P256_POINT_AFFINE *in_t, int idx); |
4d3fa06f AP |
123 | |
124 | /* One converted into the Montgomery domain */ | |
125 | static const BN_ULONG ONE[P256_LIMBS] = { | |
126 | TOBN(0x00000000, 0x00000001), TOBN(0xffffffff, 0x00000000), | |
127 | TOBN(0xffffffff, 0xffffffff), TOBN(0x00000000, 0xfffffffe) | |
128 | }; | |
129 | ||
3aef36ff | 130 | static NISTZ256_PRE_COMP *ecp_nistz256_pre_comp_new(const EC_GROUP *group); |
4d3fa06f AP |
131 | |
132 | /* Precomputed tables for the default generator */ | |
3ff08e1d | 133 | extern const PRECOMP256_ROW ecp_nistz256_precomputed[37]; |
4d3fa06f AP |
134 | |
135 | /* Recode window to a signed digit, see ecp_nistputil.c for details */ | |
136 | static unsigned int _booth_recode_w5(unsigned int in) | |
137 | { | |
138 | unsigned int s, d; | |
139 | ||
140 | s = ~((in >> 5) - 1); | |
141 | d = (1 << 6) - in - 1; | |
142 | d = (d & s) | (in & ~s); | |
143 | d = (d >> 1) + (d & 1); | |
144 | ||
145 | return (d << 1) + (s & 1); | |
146 | } | |
147 | ||
148 | static unsigned int _booth_recode_w7(unsigned int in) | |
149 | { | |
150 | unsigned int s, d; | |
151 | ||
152 | s = ~((in >> 7) - 1); | |
153 | d = (1 << 8) - in - 1; | |
154 | d = (d & s) | (in & ~s); | |
155 | d = (d >> 1) + (d & 1); | |
156 | ||
157 | return (d << 1) + (s & 1); | |
158 | } | |
159 | ||
160 | static void copy_conditional(BN_ULONG dst[P256_LIMBS], | |
161 | const BN_ULONG src[P256_LIMBS], BN_ULONG move) | |
162 | { | |
5afc296a | 163 | BN_ULONG mask1 = 0-move; |
4d3fa06f AP |
164 | BN_ULONG mask2 = ~mask1; |
165 | ||
166 | dst[0] = (src[0] & mask1) ^ (dst[0] & mask2); | |
167 | dst[1] = (src[1] & mask1) ^ (dst[1] & mask2); | |
168 | dst[2] = (src[2] & mask1) ^ (dst[2] & mask2); | |
169 | dst[3] = (src[3] & mask1) ^ (dst[3] & mask2); | |
170 | if (P256_LIMBS == 8) { | |
171 | dst[4] = (src[4] & mask1) ^ (dst[4] & mask2); | |
172 | dst[5] = (src[5] & mask1) ^ (dst[5] & mask2); | |
173 | dst[6] = (src[6] & mask1) ^ (dst[6] & mask2); | |
174 | dst[7] = (src[7] & mask1) ^ (dst[7] & mask2); | |
175 | } | |
176 | } | |
177 | ||
178 | static BN_ULONG is_zero(BN_ULONG in) | |
179 | { | |
180 | in |= (0 - in); | |
181 | in = ~in; | |
182 | in &= BN_MASK2; | |
183 | in >>= BN_BITS2 - 1; | |
184 | return in; | |
185 | } | |
186 | ||
187 | static 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 | ||
206 | static 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 |
224 | void ecp_nistz256_point_double(P256_POINT *r, const P256_POINT *a); |
225 | void ecp_nistz256_point_add(P256_POINT *r, | |
226 | const P256_POINT *a, const P256_POINT *b); | |
227 | void 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 | 232 | static 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 |
278 | static 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 |
380 | static 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 */ | |
466 | static 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 AP |
627 | /* |
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 */ | |
728 | const static BN_ULONG def_xG[P256_LIMBS] = { | |
729 | TOBN(0x79e730d4, 0x18a9143c), TOBN(0x75ba95fc, 0x5fedb601), | |
730 | TOBN(0x79fb732b, 0x77622510), TOBN(0x18905f76, 0xa53755c6) | |
731 | }; | |
732 | ||
733 | const 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 | 742 | static 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 | */ | |
4d3fa06f AP |
760 | BIGNUM *order; |
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 RS |
771 | /* if there is an old NISTZ256_PRE_COMP object, throw it away */ |
772 | EC_nistz256_pre_comp_free(group->pre_comp.nistz256); | |
b098dcae | 773 | group->pre_comp.nistz256 = NULL; |
4d3fa06f AP |
774 | generator = EC_GROUP_get0_generator(group); |
775 | if (generator == NULL) { | |
be07ae9b | 776 | ECerr(EC_F_ECP_NISTZ256_MULT_PRECOMPUTE, EC_R_UNDEFINED_GENERATOR); |
4d3fa06f AP |
777 | return 0; |
778 | } | |
779 | ||
780 | if (ecp_nistz256_is_affine_G(generator)) { | |
20728adc AP |
781 | /* |
782 | * No need to calculate tables for the standard generator because we | |
783 | * have them statically. | |
784 | */ | |
4d3fa06f AP |
785 | return 1; |
786 | } | |
787 | ||
be07ae9b | 788 | if ((pre_comp = ecp_nistz256_pre_comp_new(group)) == NULL) |
4d3fa06f AP |
789 | return 0; |
790 | ||
791 | if (ctx == NULL) { | |
53dd4ddf | 792 | ctx = new_ctx = BN_CTX_new(); |
4d3fa06f AP |
793 | if (ctx == NULL) |
794 | goto err; | |
795 | } | |
796 | ||
797 | BN_CTX_start(ctx); | |
798 | order = BN_CTX_get(ctx); | |
799 | ||
800 | if (order == NULL) | |
801 | goto err; | |
802 | ||
803 | if (!EC_GROUP_get_order(group, order, ctx)) | |
804 | goto err; | |
805 | ||
806 | if (BN_is_zero(order)) { | |
be07ae9b | 807 | ECerr(EC_F_ECP_NISTZ256_MULT_PRECOMPUTE, EC_R_UNKNOWN_ORDER); |
4d3fa06f AP |
808 | goto err; |
809 | } | |
810 | ||
811 | w = 7; | |
812 | ||
813 | if ((precomp_storage = | |
814 | OPENSSL_malloc(37 * 64 * sizeof(P256_POINT_AFFINE) + 64)) == NULL) { | |
be07ae9b | 815 | ECerr(EC_F_ECP_NISTZ256_MULT_PRECOMPUTE, ERR_R_MALLOC_FAILURE); |
4d3fa06f | 816 | goto err; |
4d3fa06f AP |
817 | } |
818 | ||
3ff08e1d AP |
819 | preComputedTable = (void *)ALIGNPTR(precomp_storage, 64); |
820 | ||
4d3fa06f AP |
821 | P = EC_POINT_new(group); |
822 | T = EC_POINT_new(group); | |
53dd4ddf EK |
823 | if (P == NULL || T == NULL) |
824 | goto err; | |
4d3fa06f | 825 | |
20728adc AP |
826 | /* |
827 | * The zero entry is implicitly infinity, and we skip it, storing other | |
828 | * values with -1 offset. | |
829 | */ | |
53dd4ddf EK |
830 | if (!EC_POINT_copy(T, generator)) |
831 | goto err; | |
4d3fa06f AP |
832 | |
833 | for (k = 0; k < 64; k++) { | |
53dd4ddf EK |
834 | if (!EC_POINT_copy(P, T)) |
835 | goto err; | |
4d3fa06f | 836 | for (j = 0; j < 37; j++) { |
3ff08e1d | 837 | P256_POINT_AFFINE temp; |
20728adc | 838 | /* |
6038354c | 839 | * It would be faster to use EC_POINTs_make_affine and |
20728adc AP |
840 | * make multiple points affine at the same time. |
841 | */ | |
6038354c EK |
842 | if (!EC_POINT_make_affine(group, P, ctx)) |
843 | goto err; | |
844 | if (!ecp_nistz256_bignum_to_field_elem(temp.X, P->X) || | |
845 | !ecp_nistz256_bignum_to_field_elem(temp.Y, P->Y)) { | |
846 | ECerr(EC_F_ECP_NISTZ256_MULT_PRECOMPUTE, | |
847 | EC_R_COORDINATES_OUT_OF_RANGE); | |
848 | goto err; | |
849 | } | |
3ff08e1d | 850 | ecp_nistz256_scatter_w7(preComputedTable[j], &temp, k); |
6038354c EK |
851 | for (i = 0; i < 7; i++) { |
852 | if (!EC_POINT_dbl(group, P, P, ctx)) | |
853 | goto err; | |
854 | } | |
4d3fa06f | 855 | } |
6038354c EK |
856 | if (!EC_POINT_add(group, T, T, generator, ctx)) |
857 | goto err; | |
4d3fa06f AP |
858 | } |
859 | ||
860 | pre_comp->group = group; | |
861 | pre_comp->w = w; | |
862 | pre_comp->precomp = preComputedTable; | |
863 | pre_comp->precomp_storage = precomp_storage; | |
4d3fa06f | 864 | precomp_storage = NULL; |
3aef36ff | 865 | SETPRECOMP(group, nistz256, pre_comp); |
4d3fa06f | 866 | pre_comp = NULL; |
4d3fa06f AP |
867 | ret = 1; |
868 | ||
58d47cf0 | 869 | err: |
4d3fa06f AP |
870 | if (ctx != NULL) |
871 | BN_CTX_end(ctx); | |
53dd4ddf EK |
872 | BN_CTX_free(new_ctx); |
873 | ||
3aef36ff | 874 | EC_nistz256_pre_comp_free(pre_comp); |
b548a1f1 | 875 | OPENSSL_free(precomp_storage); |
8fdc3734 RS |
876 | EC_POINT_free(P); |
877 | EC_POINT_free(T); | |
4d3fa06f AP |
878 | return ret; |
879 | } | |
880 | ||
881 | /* | |
882 | * Note that by default ECP_NISTZ256_AVX2 is undefined. While it's great | |
883 | * code processing 4 points in parallel, corresponding serial operation | |
884 | * is several times slower, because it uses 29x29=58-bit multiplication | |
885 | * as opposite to 64x64=128-bit in integer-only scalar case. As result | |
886 | * it doesn't provide *significant* performance improvement. Note that | |
887 | * just defining ECP_NISTZ256_AVX2 is not sufficient to make it work, | |
888 | * you'd need to compile even asm/ecp_nistz256-avx.pl module. | |
889 | */ | |
890 | #if defined(ECP_NISTZ256_AVX2) | |
3ff08e1d | 891 | # if !(defined(__x86_64) || defined(__x86_64__) || \ |
4d3fa06f AP |
892 | defined(_M_AMD64) || defined(_MX64)) || \ |
893 | !(defined(__GNUC__) || defined(_MSC_VER)) /* this is for ALIGN32 */ | |
894 | # undef ECP_NISTZ256_AVX2 | |
895 | # else | |
896 | /* Constant time access, loading four values, from four consecutive tables */ | |
58d47cf0 AP |
897 | void ecp_nistz256_avx2_multi_gather_w7(void *result, const void *in, |
898 | int index0, int index1, int index2, | |
899 | int index3); | |
4d3fa06f AP |
900 | void ecp_nistz256_avx2_transpose_convert(void *RESULTx4, const void *in); |
901 | void ecp_nistz256_avx2_convert_transpose_back(void *result, const void *Ax4); | |
902 | void ecp_nistz256_avx2_point_add_affine_x4(void *RESULTx4, const void *Ax4, | |
903 | const void *Bx4); | |
904 | void ecp_nistz256_avx2_point_add_affines_x4(void *RESULTx4, const void *Ax4, | |
905 | const void *Bx4); | |
906 | void ecp_nistz256_avx2_to_mont(void *RESULTx4, const void *Ax4); | |
907 | void ecp_nistz256_avx2_from_mont(void *RESULTx4, const void *Ax4); | |
908 | void ecp_nistz256_avx2_set1(void *RESULTx4); | |
909 | int ecp_nistz_avx2_eligible(void); | |
910 | ||
911 | static void booth_recode_w7(unsigned char *sign, | |
912 | unsigned char *digit, unsigned char in) | |
913 | { | |
914 | unsigned char s, d; | |
915 | ||
916 | s = ~((in >> 7) - 1); | |
917 | d = (1 << 8) - in - 1; | |
918 | d = (d & s) | (in & ~s); | |
919 | d = (d >> 1) + (d & 1); | |
920 | ||
921 | *sign = s & 1; | |
922 | *digit = d; | |
923 | } | |
924 | ||
20728adc AP |
925 | /* |
926 | * ecp_nistz256_avx2_mul_g performs multiplication by G, using only the | |
4d3fa06f | 927 | * precomputed table. It does 4 affine point additions in parallel, |
20728adc AP |
928 | * significantly speeding up point multiplication for a fixed value. |
929 | */ | |
58d47cf0 | 930 | static void ecp_nistz256_avx2_mul_g(P256_POINT *r, |
4d3fa06f | 931 | unsigned char p_str[33], |
58d47cf0 | 932 | const P256_POINT_AFFINE(*preComputedTable)[64]) |
4d3fa06f AP |
933 | { |
934 | const unsigned int window_size = 7; | |
935 | const unsigned int mask = (1 << (window_size + 1)) - 1; | |
936 | unsigned int wvalue; | |
937 | /* Using 4 windows at a time */ | |
938 | unsigned char sign0, digit0; | |
939 | unsigned char sign1, digit1; | |
940 | unsigned char sign2, digit2; | |
941 | unsigned char sign3, digit3; | |
49b05c7d | 942 | unsigned int idx = 0; |
4d3fa06f AP |
943 | BN_ULONG tmp[P256_LIMBS]; |
944 | int i; | |
945 | ||
946 | ALIGN32 BN_ULONG aX4[4 * 9 * 3] = { 0 }; | |
947 | ALIGN32 BN_ULONG bX4[4 * 9 * 2] = { 0 }; | |
3ff08e1d AP |
948 | ALIGN32 P256_POINT_AFFINE point_arr[4]; |
949 | ALIGN32 P256_POINT res_point_arr[4]; | |
4d3fa06f AP |
950 | |
951 | /* Initial four windows */ | |
952 | wvalue = *((u16 *) & p_str[0]); | |
953 | wvalue = (wvalue << 1) & mask; | |
49b05c7d | 954 | idx += window_size; |
4d3fa06f | 955 | booth_recode_w7(&sign0, &digit0, 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(&sign1, &digit1, wvalue); |
49b05c7d RS |
960 | wvalue = *((u16 *) & p_str[(idx - 1) / 8]); |
961 | wvalue = (wvalue >> ((idx - 1) % 8)) & mask; | |
962 | idx += window_size; | |
4d3fa06f | 963 | booth_recode_w7(&sign2, &digit2, wvalue); |
49b05c7d RS |
964 | wvalue = *((u16 *) & p_str[(idx - 1) / 8]); |
965 | wvalue = (wvalue >> ((idx - 1) % 8)) & mask; | |
966 | idx += window_size; | |
4d3fa06f AP |
967 | booth_recode_w7(&sign3, &digit3, wvalue); |
968 | ||
3ff08e1d | 969 | ecp_nistz256_avx2_multi_gather_w7(point_arr, preComputedTable[0], |
4d3fa06f AP |
970 | digit0, digit1, digit2, digit3); |
971 | ||
972 | ecp_nistz256_neg(tmp, point_arr[0].Y); | |
973 | copy_conditional(point_arr[0].Y, tmp, sign0); | |
974 | ecp_nistz256_neg(tmp, point_arr[1].Y); | |
975 | copy_conditional(point_arr[1].Y, tmp, sign1); | |
976 | ecp_nistz256_neg(tmp, point_arr[2].Y); | |
977 | copy_conditional(point_arr[2].Y, tmp, sign2); | |
978 | ecp_nistz256_neg(tmp, point_arr[3].Y); | |
979 | copy_conditional(point_arr[3].Y, tmp, sign3); | |
980 | ||
981 | ecp_nistz256_avx2_transpose_convert(aX4, point_arr); | |
982 | ecp_nistz256_avx2_to_mont(aX4, aX4); | |
983 | ecp_nistz256_avx2_to_mont(&aX4[4 * 9], &aX4[4 * 9]); | |
984 | ecp_nistz256_avx2_set1(&aX4[4 * 9 * 2]); | |
985 | ||
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(&sign0, &digit0, 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(&sign1, &digit1, wvalue); |
49b05c7d RS |
994 | wvalue = *((u16 *) & p_str[(idx - 1) / 8]); |
995 | wvalue = (wvalue >> ((idx - 1) % 8)) & mask; | |
996 | idx += window_size; | |
4d3fa06f | 997 | booth_recode_w7(&sign2, &digit2, wvalue); |
49b05c7d RS |
998 | wvalue = *((u16 *) & p_str[(idx - 1) / 8]); |
999 | wvalue = (wvalue >> ((idx - 1) % 8)) & mask; | |
1000 | idx += window_size; | |
4d3fa06f AP |
1001 | booth_recode_w7(&sign3, &digit3, wvalue); |
1002 | ||
3ff08e1d | 1003 | ecp_nistz256_avx2_multi_gather_w7(point_arr, preComputedTable[4 * 1], |
4d3fa06f AP |
1004 | digit0, digit1, digit2, digit3); |
1005 | ||
1006 | ecp_nistz256_neg(tmp, point_arr[0].Y); | |
1007 | copy_conditional(point_arr[0].Y, tmp, sign0); | |
1008 | ecp_nistz256_neg(tmp, point_arr[1].Y); | |
1009 | copy_conditional(point_arr[1].Y, tmp, sign1); | |
1010 | ecp_nistz256_neg(tmp, point_arr[2].Y); | |
1011 | copy_conditional(point_arr[2].Y, tmp, sign2); | |
1012 | ecp_nistz256_neg(tmp, point_arr[3].Y); | |
1013 | copy_conditional(point_arr[3].Y, tmp, sign3); | |
1014 | ||
1015 | ecp_nistz256_avx2_transpose_convert(bX4, point_arr); | |
1016 | ecp_nistz256_avx2_to_mont(bX4, bX4); | |
1017 | ecp_nistz256_avx2_to_mont(&bX4[4 * 9], &bX4[4 * 9]); | |
1018 | /* Optimized when both inputs are affine */ | |
1019 | ecp_nistz256_avx2_point_add_affines_x4(aX4, aX4, bX4); | |
1020 | ||
1021 | for (i = 2; i < 9; i++) { | |
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(&sign0, &digit0, 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(&sign1, &digit1, wvalue); |
49b05c7d RS |
1030 | wvalue = *((u16 *) & p_str[(idx - 1) / 8]); |
1031 | wvalue = (wvalue >> ((idx - 1) % 8)) & mask; | |
1032 | idx += window_size; | |
4d3fa06f | 1033 | booth_recode_w7(&sign2, &digit2, wvalue); |
49b05c7d RS |
1034 | wvalue = *((u16 *) & p_str[(idx - 1) / 8]); |
1035 | wvalue = (wvalue >> ((idx - 1) % 8)) & mask; | |
1036 | idx += window_size; | |
4d3fa06f AP |
1037 | booth_recode_w7(&sign3, &digit3, wvalue); |
1038 | ||
3ff08e1d | 1039 | ecp_nistz256_avx2_multi_gather_w7(point_arr, |
4d3fa06f AP |
1040 | preComputedTable[4 * i], |
1041 | digit0, digit1, digit2, digit3); | |
1042 | ||
1043 | ecp_nistz256_neg(tmp, point_arr[0].Y); | |
1044 | copy_conditional(point_arr[0].Y, tmp, sign0); | |
1045 | ecp_nistz256_neg(tmp, point_arr[1].Y); | |
1046 | copy_conditional(point_arr[1].Y, tmp, sign1); | |
1047 | ecp_nistz256_neg(tmp, point_arr[2].Y); | |
1048 | copy_conditional(point_arr[2].Y, tmp, sign2); | |
1049 | ecp_nistz256_neg(tmp, point_arr[3].Y); | |
1050 | copy_conditional(point_arr[3].Y, tmp, sign3); | |
1051 | ||
1052 | ecp_nistz256_avx2_transpose_convert(bX4, point_arr); | |
1053 | ecp_nistz256_avx2_to_mont(bX4, bX4); | |
1054 | ecp_nistz256_avx2_to_mont(&bX4[4 * 9], &bX4[4 * 9]); | |
1055 | ||
1056 | ecp_nistz256_avx2_point_add_affine_x4(aX4, aX4, bX4); | |
1057 | } | |
1058 | ||
1059 | ecp_nistz256_avx2_from_mont(&aX4[4 * 9 * 0], &aX4[4 * 9 * 0]); | |
1060 | ecp_nistz256_avx2_from_mont(&aX4[4 * 9 * 1], &aX4[4 * 9 * 1]); | |
1061 | ecp_nistz256_avx2_from_mont(&aX4[4 * 9 * 2], &aX4[4 * 9 * 2]); | |
1062 | ||
1063 | ecp_nistz256_avx2_convert_transpose_back(res_point_arr, aX4); | |
1064 | /* Last window is performed serially */ | |
49b05c7d RS |
1065 | wvalue = *((u16 *) & p_str[(idx - 1) / 8]); |
1066 | wvalue = (wvalue >> ((idx - 1) % 8)) & mask; | |
4d3fa06f | 1067 | booth_recode_w7(&sign0, &digit0, wvalue); |
58d47cf0 AP |
1068 | ecp_nistz256_gather_w7((P256_POINT_AFFINE *)r, |
1069 | preComputedTable[36], digit0); | |
4d3fa06f AP |
1070 | ecp_nistz256_neg(tmp, r->Y); |
1071 | copy_conditional(r->Y, tmp, sign0); | |
1072 | memcpy(r->Z, ONE, sizeof(ONE)); | |
1073 | /* Sum the four windows */ | |
1074 | ecp_nistz256_point_add(r, r, &res_point_arr[0]); | |
1075 | ecp_nistz256_point_add(r, r, &res_point_arr[1]); | |
1076 | ecp_nistz256_point_add(r, r, &res_point_arr[2]); | |
1077 | ecp_nistz256_point_add(r, r, &res_point_arr[3]); | |
1078 | } | |
1079 | # endif | |
1080 | #endif | |
1081 | ||
5956b110 EK |
1082 | __owur static int ecp_nistz256_set_from_affine(EC_POINT *out, const EC_GROUP *group, |
1083 | const P256_POINT_AFFINE *in, | |
1084 | BN_CTX *ctx) | |
4d3fa06f | 1085 | { |
5784a521 | 1086 | BIGNUM *x, *y; |
4d3fa06f AP |
1087 | BN_ULONG d_x[P256_LIMBS], d_y[P256_LIMBS]; |
1088 | int ret = 0; | |
1089 | ||
5784a521 | 1090 | x = BN_new(); |
90945fa3 | 1091 | if (x == NULL) |
5784a521 MC |
1092 | return 0; |
1093 | y = BN_new(); | |
90945fa3 | 1094 | if (y == NULL) { |
5784a521 MC |
1095 | BN_free(x); |
1096 | return 0; | |
1097 | } | |
4d3fa06f | 1098 | memcpy(d_x, in->X, sizeof(d_x)); |
5784a521 | 1099 | bn_set_static_words(x, d_x, P256_LIMBS); |
4d3fa06f AP |
1100 | |
1101 | memcpy(d_y, in->Y, sizeof(d_y)); | |
5784a521 MC |
1102 | bn_set_static_words(y, d_y, P256_LIMBS); |
1103 | ||
1104 | ret = EC_POINT_set_affine_coordinates_GFp(group, out, x, y, ctx); | |
4d3fa06f | 1105 | |
23a1d5e9 RS |
1106 | BN_free(x); |
1107 | BN_free(y); | |
4d3fa06f AP |
1108 | |
1109 | return ret; | |
1110 | } | |
1111 | ||
1112 | /* r = scalar*G + sum(scalars[i]*points[i]) */ | |
5956b110 EK |
1113 | __owur static int ecp_nistz256_points_mul(const EC_GROUP *group, |
1114 | EC_POINT *r, | |
1115 | const BIGNUM *scalar, | |
1116 | size_t num, | |
1117 | const EC_POINT *points[], | |
1118 | const BIGNUM *scalars[], BN_CTX *ctx) | |
4d3fa06f AP |
1119 | { |
1120 | int i = 0, ret = 0, no_precomp_for_generator = 0, p_is_infinity = 0; | |
16e5b45f | 1121 | size_t j; |
4d3fa06f AP |
1122 | unsigned char p_str[33] = { 0 }; |
1123 | const PRECOMP256_ROW *preComputedTable = NULL; | |
3aef36ff | 1124 | const NISTZ256_PRE_COMP *pre_comp = NULL; |
4d3fa06f | 1125 | const EC_POINT *generator = NULL; |
e22d2199 | 1126 | BN_CTX *new_ctx = NULL; |
a4d5269e EK |
1127 | const BIGNUM **new_scalars = NULL; |
1128 | const EC_POINT **new_points = NULL; | |
49b05c7d | 1129 | unsigned int idx = 0; |
4d3fa06f AP |
1130 | const unsigned int window_size = 7; |
1131 | const unsigned int mask = (1 << (window_size + 1)) - 1; | |
1132 | unsigned int wvalue; | |
1133 | ALIGN32 union { | |
1134 | P256_POINT p; | |
1135 | P256_POINT_AFFINE a; | |
1136 | } t, p; | |
1137 | BIGNUM *tmp_scalar; | |
1138 | ||
58d47cf0 | 1139 | if ((num + 1) == 0 || (num + 1) > OPENSSL_MALLOC_MAX_NELEMS(void *)) { |
3ff08e1d AP |
1140 | ECerr(EC_F_ECP_NISTZ256_POINTS_MUL, ERR_R_MALLOC_FAILURE); |
1141 | return 0; | |
1142 | } | |
1143 | ||
4d3fa06f | 1144 | if (group->meth != r->meth) { |
be07ae9b | 1145 | ECerr(EC_F_ECP_NISTZ256_POINTS_MUL, EC_R_INCOMPATIBLE_OBJECTS); |
4d3fa06f AP |
1146 | return 0; |
1147 | } | |
e22d2199 | 1148 | |
4d3fa06f AP |
1149 | if ((scalar == NULL) && (num == 0)) |
1150 | return EC_POINT_set_to_infinity(group, r); | |
1151 | ||
16e5b45f DSH |
1152 | for (j = 0; j < num; j++) { |
1153 | if (group->meth != points[j]->meth) { | |
be07ae9b | 1154 | ECerr(EC_F_ECP_NISTZ256_POINTS_MUL, EC_R_INCOMPATIBLE_OBJECTS); |
4d3fa06f AP |
1155 | return 0; |
1156 | } | |
1157 | } | |
1158 | ||
e22d2199 EK |
1159 | if (ctx == NULL) { |
1160 | ctx = new_ctx = BN_CTX_new(); | |
1161 | if (ctx == NULL) | |
1162 | goto err; | |
1163 | } | |
1164 | ||
1165 | BN_CTX_start(ctx); | |
4d3fa06f AP |
1166 | |
1167 | if (scalar) { | |
1168 | generator = EC_GROUP_get0_generator(group); | |
1169 | if (generator == NULL) { | |
be07ae9b | 1170 | ECerr(EC_F_ECP_NISTZ256_POINTS_MUL, EC_R_UNDEFINED_GENERATOR); |
4d3fa06f AP |
1171 | goto err; |
1172 | } | |
1173 | ||
1174 | /* look if we can use precomputed multiples of generator */ | |
3aef36ff | 1175 | pre_comp = group->pre_comp.nistz256; |
4d3fa06f AP |
1176 | |
1177 | if (pre_comp) { | |
20728adc AP |
1178 | /* |
1179 | * If there is a precomputed table for the generator, check that | |
1180 | * it was generated with the same generator. | |
1181 | */ | |
4d3fa06f AP |
1182 | EC_POINT *pre_comp_generator = EC_POINT_new(group); |
1183 | if (pre_comp_generator == NULL) | |
1184 | goto err; | |
1185 | ||
3ff08e1d AP |
1186 | if (!ecp_nistz256_set_from_affine(pre_comp_generator, |
1187 | group, pre_comp->precomp[0], | |
e22d2199 EK |
1188 | ctx)) { |
1189 | EC_POINT_free(pre_comp_generator); | |
4d3fa06f | 1190 | goto err; |
e22d2199 | 1191 | } |
4d3fa06f AP |
1192 | |
1193 | if (0 == EC_POINT_cmp(group, generator, pre_comp_generator, ctx)) | |
1194 | preComputedTable = (const PRECOMP256_ROW *)pre_comp->precomp; | |
1195 | ||
1196 | EC_POINT_free(pre_comp_generator); | |
1197 | } | |
1198 | ||
1199 | if (preComputedTable == NULL && ecp_nistz256_is_affine_G(generator)) { | |
20728adc AP |
1200 | /* |
1201 | * If there is no precomputed data, but the generator is the | |
1202 | * default, a hardcoded table of precomputed data is used. This | |
1203 | * is because applications, such as Apache, do not use | |
1204 | * EC_KEY_precompute_mult. | |
1205 | */ | |
3ff08e1d | 1206 | preComputedTable = ecp_nistz256_precomputed; |
4d3fa06f AP |
1207 | } |
1208 | ||
1209 | if (preComputedTable) { | |
1210 | if ((BN_num_bits(scalar) > 256) | |
1211 | || BN_is_negative(scalar)) { | |
1212 | if ((tmp_scalar = BN_CTX_get(ctx)) == NULL) | |
1213 | goto err; | |
1214 | ||
5784a521 | 1215 | if (!BN_nnmod(tmp_scalar, scalar, group->order, ctx)) { |
be07ae9b | 1216 | ECerr(EC_F_ECP_NISTZ256_POINTS_MUL, ERR_R_BN_LIB); |
4d3fa06f AP |
1217 | goto err; |
1218 | } | |
1219 | scalar = tmp_scalar; | |
1220 | } | |
1221 | ||
5784a521 MC |
1222 | for (i = 0; i < bn_get_top(scalar) * BN_BYTES; i += BN_BYTES) { |
1223 | BN_ULONG d = bn_get_words(scalar)[i / BN_BYTES]; | |
4d3fa06f | 1224 | |
5afc296a AP |
1225 | p_str[i + 0] = (unsigned char)d; |
1226 | p_str[i + 1] = (unsigned char)(d >> 8); | |
1227 | p_str[i + 2] = (unsigned char)(d >> 16); | |
1228 | p_str[i + 3] = (unsigned char)(d >>= 24); | |
4d3fa06f AP |
1229 | if (BN_BYTES == 8) { |
1230 | d >>= 8; | |
5afc296a AP |
1231 | p_str[i + 4] = (unsigned char)d; |
1232 | p_str[i + 5] = (unsigned char)(d >> 8); | |
1233 | p_str[i + 6] = (unsigned char)(d >> 16); | |
1234 | p_str[i + 7] = (unsigned char)(d >> 24); | |
4d3fa06f AP |
1235 | } |
1236 | } | |
1237 | ||
1238 | for (; i < 33; i++) | |
1239 | p_str[i] = 0; | |
1240 | ||
1241 | #if defined(ECP_NISTZ256_AVX2) | |
1242 | if (ecp_nistz_avx2_eligible()) { | |
1243 | ecp_nistz256_avx2_mul_g(&p.p, p_str, preComputedTable); | |
1244 | } else | |
1245 | #endif | |
1246 | { | |
1247 | /* First window */ | |
1248 | wvalue = (p_str[0] << 1) & mask; | |
49b05c7d | 1249 | idx += window_size; |
4d3fa06f AP |
1250 | |
1251 | wvalue = _booth_recode_w7(wvalue); | |
1252 | ||
58d47cf0 AP |
1253 | ecp_nistz256_gather_w7(&p.a, preComputedTable[0], |
1254 | wvalue >> 1); | |
4d3fa06f AP |
1255 | |
1256 | ecp_nistz256_neg(p.p.Z, p.p.Y); | |
1257 | copy_conditional(p.p.Y, p.p.Z, wvalue & 1); | |
1258 | ||
1259 | memcpy(p.p.Z, ONE, sizeof(ONE)); | |
1260 | ||
1261 | for (i = 1; i < 37; i++) { | |
49b05c7d | 1262 | unsigned int off = (idx - 1) / 8; |
4d3fa06f | 1263 | wvalue = p_str[off] | p_str[off + 1] << 8; |
49b05c7d RS |
1264 | wvalue = (wvalue >> ((idx - 1) % 8)) & mask; |
1265 | idx += window_size; | |
4d3fa06f AP |
1266 | |
1267 | wvalue = _booth_recode_w7(wvalue); | |
1268 | ||
3ff08e1d | 1269 | ecp_nistz256_gather_w7(&t.a, |
4d3fa06f AP |
1270 | preComputedTable[i], wvalue >> 1); |
1271 | ||
1272 | ecp_nistz256_neg(t.p.Z, t.a.Y); | |
1273 | copy_conditional(t.a.Y, t.p.Z, wvalue & 1); | |
1274 | ||
1275 | ecp_nistz256_point_add_affine(&p.p, &p.p, &t.a); | |
1276 | } | |
1277 | } | |
1278 | } else { | |
1279 | p_is_infinity = 1; | |
1280 | no_precomp_for_generator = 1; | |
1281 | } | |
1282 | } else | |
1283 | p_is_infinity = 1; | |
1284 | ||
1285 | if (no_precomp_for_generator) { | |
20728adc AP |
1286 | /* |
1287 | * Without a precomputed table for the generator, it has to be | |
1288 | * handled like a normal point. | |
1289 | */ | |
4d3fa06f | 1290 | new_scalars = OPENSSL_malloc((num + 1) * sizeof(BIGNUM *)); |
90945fa3 | 1291 | if (new_scalars == NULL) { |
be07ae9b | 1292 | ECerr(EC_F_ECP_NISTZ256_POINTS_MUL, ERR_R_MALLOC_FAILURE); |
e22d2199 | 1293 | goto err; |
4d3fa06f AP |
1294 | } |
1295 | ||
1296 | new_points = OPENSSL_malloc((num + 1) * sizeof(EC_POINT *)); | |
90945fa3 | 1297 | if (new_points == NULL) { |
be07ae9b | 1298 | ECerr(EC_F_ECP_NISTZ256_POINTS_MUL, ERR_R_MALLOC_FAILURE); |
e22d2199 | 1299 | goto err; |
4d3fa06f AP |
1300 | } |
1301 | ||
1302 | memcpy(new_scalars, scalars, num * sizeof(BIGNUM *)); | |
1303 | new_scalars[num] = scalar; | |
1304 | memcpy(new_points, points, num * sizeof(EC_POINT *)); | |
1305 | new_points[num] = generator; | |
1306 | ||
1307 | scalars = new_scalars; | |
1308 | points = new_points; | |
1309 | num++; | |
1310 | } | |
1311 | ||
1312 | if (num) { | |
1313 | P256_POINT *out = &t.p; | |
1314 | if (p_is_infinity) | |
1315 | out = &p.p; | |
1316 | ||
a4d5269e EK |
1317 | if (!ecp_nistz256_windowed_mul(group, out, scalars, points, num, ctx)) |
1318 | goto err; | |
4d3fa06f AP |
1319 | |
1320 | if (!p_is_infinity) | |
1321 | ecp_nistz256_point_add(&p.p, &p.p, out); | |
1322 | } | |
1323 | ||
c028254b | 1324 | /* Not constant-time, but we're only operating on the public output. */ |
e22d2199 EK |
1325 | if (!bn_set_words(r->X, p.p.X, P256_LIMBS) || |
1326 | !bn_set_words(r->Y, p.p.Y, P256_LIMBS) || | |
1327 | !bn_set_words(r->Z, p.p.Z, P256_LIMBS)) { | |
1328 | goto err; | |
1329 | } | |
4446044a | 1330 | r->Z_is_one = is_one(p.p.Z) & 1; |
4d3fa06f AP |
1331 | |
1332 | ret = 1; | |
1333 | ||
e22d2199 EK |
1334 | err: |
1335 | if (ctx) | |
1336 | BN_CTX_end(ctx); | |
1337 | BN_CTX_free(new_ctx); | |
b548a1f1 RS |
1338 | OPENSSL_free(new_points); |
1339 | OPENSSL_free(new_scalars); | |
4d3fa06f AP |
1340 | return ret; |
1341 | } | |
1342 | ||
5956b110 EK |
1343 | __owur static int ecp_nistz256_get_affine(const EC_GROUP *group, |
1344 | const EC_POINT *point, | |
1345 | BIGNUM *x, BIGNUM *y, BN_CTX *ctx) | |
4d3fa06f AP |
1346 | { |
1347 | BN_ULONG z_inv2[P256_LIMBS]; | |
1348 | BN_ULONG z_inv3[P256_LIMBS]; | |
1349 | BN_ULONG x_aff[P256_LIMBS]; | |
1350 | BN_ULONG y_aff[P256_LIMBS]; | |
1351 | BN_ULONG point_x[P256_LIMBS], point_y[P256_LIMBS], point_z[P256_LIMBS]; | |
e22d2199 | 1352 | BN_ULONG x_ret[P256_LIMBS], y_ret[P256_LIMBS]; |
4d3fa06f AP |
1353 | |
1354 | if (EC_POINT_is_at_infinity(group, point)) { | |
be07ae9b | 1355 | ECerr(EC_F_ECP_NISTZ256_GET_AFFINE, EC_R_POINT_AT_INFINITY); |
4d3fa06f AP |
1356 | return 0; |
1357 | } | |
1358 | ||
5784a521 MC |
1359 | if (!ecp_nistz256_bignum_to_field_elem(point_x, point->X) || |
1360 | !ecp_nistz256_bignum_to_field_elem(point_y, point->Y) || | |
1361 | !ecp_nistz256_bignum_to_field_elem(point_z, point->Z)) { | |
be07ae9b | 1362 | ECerr(EC_F_ECP_NISTZ256_GET_AFFINE, EC_R_COORDINATES_OUT_OF_RANGE); |
4d3fa06f AP |
1363 | return 0; |
1364 | } | |
1365 | ||
1366 | ecp_nistz256_mod_inverse(z_inv3, point_z); | |
1367 | ecp_nistz256_sqr_mont(z_inv2, z_inv3); | |
1368 | ecp_nistz256_mul_mont(x_aff, z_inv2, point_x); | |
1369 | ||
1370 | if (x != NULL) { | |
e22d2199 EK |
1371 | ecp_nistz256_from_mont(x_ret, x_aff); |
1372 | if (!bn_set_words(x, x_ret, P256_LIMBS)) | |
1373 | return 0; | |
4d3fa06f AP |
1374 | } |
1375 | ||
1376 | if (y != NULL) { | |
1377 | ecp_nistz256_mul_mont(z_inv3, z_inv3, z_inv2); | |
1378 | ecp_nistz256_mul_mont(y_aff, z_inv3, point_y); | |
e22d2199 EK |
1379 | ecp_nistz256_from_mont(y_ret, y_aff); |
1380 | if (!bn_set_words(y, y_ret, P256_LIMBS)) | |
1381 | return 0; | |
4d3fa06f AP |
1382 | } |
1383 | ||
1384 | return 1; | |
1385 | } | |
1386 | ||
3aef36ff | 1387 | static NISTZ256_PRE_COMP *ecp_nistz256_pre_comp_new(const EC_GROUP *group) |
4d3fa06f | 1388 | { |
3aef36ff | 1389 | NISTZ256_PRE_COMP *ret = NULL; |
4d3fa06f AP |
1390 | |
1391 | if (!group) | |
1392 | return NULL; | |
1393 | ||
3aef36ff | 1394 | ret = OPENSSL_zalloc(sizeof(*ret)); |
4d3fa06f | 1395 | |
90945fa3 | 1396 | if (ret == NULL) { |
be07ae9b | 1397 | ECerr(EC_F_ECP_NISTZ256_PRE_COMP_NEW, ERR_R_MALLOC_FAILURE); |
4d3fa06f AP |
1398 | return ret; |
1399 | } | |
1400 | ||
1401 | ret->group = group; | |
1402 | ret->w = 6; /* default */ | |
1403 | ret->precomp = NULL; | |
1404 | ret->precomp_storage = NULL; | |
1405 | ret->references = 1; | |
1406 | return ret; | |
1407 | } | |
1408 | ||
3aef36ff | 1409 | NISTZ256_PRE_COMP *EC_nistz256_pre_comp_dup(NISTZ256_PRE_COMP *p) |
4d3fa06f | 1410 | { |
3aef36ff RS |
1411 | if (p != NULL) |
1412 | CRYPTO_add(&p->references, 1, CRYPTO_LOCK_EC_PRE_COMP); | |
1413 | return p; | |
4d3fa06f AP |
1414 | } |
1415 | ||
3aef36ff | 1416 | void EC_nistz256_pre_comp_free(NISTZ256_PRE_COMP *pre) |
4d3fa06f | 1417 | { |
3aef36ff RS |
1418 | if (pre == NULL |
1419 | || CRYPTO_add(&pre->references, -1, CRYPTO_LOCK_EC_PRE_COMP) > 0) | |
4d3fa06f | 1420 | return; |
b548a1f1 | 1421 | OPENSSL_free(pre->precomp_storage); |
4d3fa06f AP |
1422 | OPENSSL_free(pre); |
1423 | } | |
1424 | ||
4d3fa06f | 1425 | |
58d47cf0 | 1426 | static int ecp_nistz256_window_have_precompute_mult(const EC_GROUP *group) |
4d3fa06f AP |
1427 | { |
1428 | /* There is a hard-coded table for the default generator. */ | |
1429 | const EC_POINT *generator = EC_GROUP_get0_generator(group); | |
3aef36ff | 1430 | |
4d3fa06f AP |
1431 | if (generator != NULL && ecp_nistz256_is_affine_G(generator)) { |
1432 | /* There is a hard-coded table for the default generator. */ | |
1433 | return 1; | |
1434 | } | |
1435 | ||
3aef36ff | 1436 | return HAVEPRECOMP(group, nistz256); |
4d3fa06f AP |
1437 | } |
1438 | ||
1439 | const EC_METHOD *EC_GFp_nistz256_method(void) | |
1440 | { | |
1441 | static const EC_METHOD ret = { | |
1442 | EC_FLAGS_DEFAULT_OCT, | |
1443 | NID_X9_62_prime_field, | |
1444 | ec_GFp_mont_group_init, | |
1445 | ec_GFp_mont_group_finish, | |
1446 | ec_GFp_mont_group_clear_finish, | |
1447 | ec_GFp_mont_group_copy, | |
1448 | ec_GFp_mont_group_set_curve, | |
1449 | ec_GFp_simple_group_get_curve, | |
1450 | ec_GFp_simple_group_get_degree, | |
1451 | ec_GFp_simple_group_check_discriminant, | |
1452 | ec_GFp_simple_point_init, | |
1453 | ec_GFp_simple_point_finish, | |
1454 | ec_GFp_simple_point_clear_finish, | |
1455 | ec_GFp_simple_point_copy, | |
1456 | ec_GFp_simple_point_set_to_infinity, | |
1457 | ec_GFp_simple_set_Jprojective_coordinates_GFp, | |
1458 | ec_GFp_simple_get_Jprojective_coordinates_GFp, | |
1459 | ec_GFp_simple_point_set_affine_coordinates, | |
1460 | ecp_nistz256_get_affine, | |
1461 | 0, 0, 0, | |
1462 | ec_GFp_simple_add, | |
1463 | ec_GFp_simple_dbl, | |
1464 | ec_GFp_simple_invert, | |
1465 | ec_GFp_simple_is_at_infinity, | |
1466 | ec_GFp_simple_is_on_curve, | |
1467 | ec_GFp_simple_cmp, | |
1468 | ec_GFp_simple_make_affine, | |
1469 | ec_GFp_simple_points_make_affine, | |
1470 | ecp_nistz256_points_mul, /* mul */ | |
1471 | ecp_nistz256_mult_precompute, /* precompute_mult */ | |
1472 | ecp_nistz256_window_have_precompute_mult, /* have_precompute_mult */ | |
1473 | ec_GFp_mont_field_mul, | |
1474 | ec_GFp_mont_field_sqr, | |
1475 | 0, /* field_div */ | |
1476 | ec_GFp_mont_field_encode, | |
1477 | ec_GFp_mont_field_decode, | |
1478 | ec_GFp_mont_field_set_to_one | |
1479 | }; | |
1480 | ||
1481 | return &ret; | |
1482 | } |