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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 | ||
4d3fa06f | 31 | #include "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 */ | |
68 | typedef struct ec_pre_comp_st { | |
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; | |
79 | } EC_PRE_COMP; | |
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 | ||
be07ae9b AP |
130 | static void *ecp_nistz256_pre_comp_dup(void *); |
131 | static void ecp_nistz256_pre_comp_free(void *); | |
132 | static void ecp_nistz256_pre_comp_clear_free(void *); | |
58d47cf0 | 133 | static EC_PRE_COMP *ecp_nistz256_pre_comp_new(const EC_GROUP *group); |
4d3fa06f AP |
134 | |
135 | /* Precomputed tables for the default generator */ | |
3ff08e1d | 136 | extern const PRECOMP256_ROW ecp_nistz256_precomputed[37]; |
4d3fa06f AP |
137 | |
138 | /* Recode window to a signed digit, see ecp_nistputil.c for details */ | |
139 | static unsigned int _booth_recode_w5(unsigned int in) | |
140 | { | |
141 | unsigned int s, d; | |
142 | ||
143 | s = ~((in >> 5) - 1); | |
144 | d = (1 << 6) - in - 1; | |
145 | d = (d & s) | (in & ~s); | |
146 | d = (d >> 1) + (d & 1); | |
147 | ||
148 | return (d << 1) + (s & 1); | |
149 | } | |
150 | ||
151 | static unsigned int _booth_recode_w7(unsigned int in) | |
152 | { | |
153 | unsigned int s, d; | |
154 | ||
155 | s = ~((in >> 7) - 1); | |
156 | d = (1 << 8) - in - 1; | |
157 | d = (d & s) | (in & ~s); | |
158 | d = (d >> 1) + (d & 1); | |
159 | ||
160 | return (d << 1) + (s & 1); | |
161 | } | |
162 | ||
163 | static void copy_conditional(BN_ULONG dst[P256_LIMBS], | |
164 | const BN_ULONG src[P256_LIMBS], BN_ULONG move) | |
165 | { | |
5afc296a | 166 | BN_ULONG mask1 = 0-move; |
4d3fa06f AP |
167 | BN_ULONG mask2 = ~mask1; |
168 | ||
169 | dst[0] = (src[0] & mask1) ^ (dst[0] & mask2); | |
170 | dst[1] = (src[1] & mask1) ^ (dst[1] & mask2); | |
171 | dst[2] = (src[2] & mask1) ^ (dst[2] & mask2); | |
172 | dst[3] = (src[3] & mask1) ^ (dst[3] & mask2); | |
173 | if (P256_LIMBS == 8) { | |
174 | dst[4] = (src[4] & mask1) ^ (dst[4] & mask2); | |
175 | dst[5] = (src[5] & mask1) ^ (dst[5] & mask2); | |
176 | dst[6] = (src[6] & mask1) ^ (dst[6] & mask2); | |
177 | dst[7] = (src[7] & mask1) ^ (dst[7] & mask2); | |
178 | } | |
179 | } | |
180 | ||
181 | static BN_ULONG is_zero(BN_ULONG in) | |
182 | { | |
183 | in |= (0 - in); | |
184 | in = ~in; | |
185 | in &= BN_MASK2; | |
186 | in >>= BN_BITS2 - 1; | |
187 | return in; | |
188 | } | |
189 | ||
190 | static BN_ULONG is_equal(const BN_ULONG a[P256_LIMBS], | |
191 | const BN_ULONG b[P256_LIMBS]) | |
192 | { | |
193 | BN_ULONG res; | |
194 | ||
195 | res = a[0] ^ b[0]; | |
196 | res |= a[1] ^ b[1]; | |
197 | res |= a[2] ^ b[2]; | |
198 | res |= a[3] ^ b[3]; | |
199 | if (P256_LIMBS == 8) { | |
200 | res |= a[4] ^ b[4]; | |
201 | res |= a[5] ^ b[5]; | |
202 | res |= a[6] ^ b[6]; | |
203 | res |= a[7] ^ b[7]; | |
204 | } | |
205 | ||
206 | return is_zero(res); | |
207 | } | |
208 | ||
209 | static BN_ULONG is_one(const BN_ULONG a[P256_LIMBS]) | |
210 | { | |
211 | BN_ULONG res; | |
212 | ||
213 | res = a[0] ^ ONE[0]; | |
214 | res |= a[1] ^ ONE[1]; | |
215 | res |= a[2] ^ ONE[2]; | |
216 | res |= a[3] ^ ONE[3]; | |
217 | if (P256_LIMBS == 8) { | |
218 | res |= a[4] ^ ONE[4]; | |
219 | res |= a[5] ^ ONE[5]; | |
220 | res |= a[6] ^ ONE[6]; | |
221 | } | |
222 | ||
223 | return is_zero(res); | |
224 | } | |
225 | ||
226 | #ifndef ECP_NISTZ256_REFERENCE_IMPLEMENTATION | |
58d47cf0 AP |
227 | void ecp_nistz256_point_double(P256_POINT *r, const P256_POINT *a); |
228 | void ecp_nistz256_point_add(P256_POINT *r, | |
229 | const P256_POINT *a, const P256_POINT *b); | |
230 | void ecp_nistz256_point_add_affine(P256_POINT *r, | |
231 | const P256_POINT *a, | |
232 | const P256_POINT_AFFINE *b); | |
4d3fa06f AP |
233 | #else |
234 | /* Point double: r = 2*a */ | |
58d47cf0 | 235 | static void ecp_nistz256_point_double(P256_POINT *r, const P256_POINT *a) |
4d3fa06f AP |
236 | { |
237 | BN_ULONG S[P256_LIMBS]; | |
238 | BN_ULONG M[P256_LIMBS]; | |
239 | BN_ULONG Zsqr[P256_LIMBS]; | |
240 | BN_ULONG tmp0[P256_LIMBS]; | |
241 | ||
242 | const BN_ULONG *in_x = a->X; | |
243 | const BN_ULONG *in_y = a->Y; | |
244 | const BN_ULONG *in_z = a->Z; | |
245 | ||
246 | BN_ULONG *res_x = r->X; | |
247 | BN_ULONG *res_y = r->Y; | |
248 | BN_ULONG *res_z = r->Z; | |
249 | ||
250 | ecp_nistz256_mul_by_2(S, in_y); | |
251 | ||
252 | ecp_nistz256_sqr_mont(Zsqr, in_z); | |
253 | ||
254 | ecp_nistz256_sqr_mont(S, S); | |
255 | ||
256 | ecp_nistz256_mul_mont(res_z, in_z, in_y); | |
257 | ecp_nistz256_mul_by_2(res_z, res_z); | |
258 | ||
259 | ecp_nistz256_add(M, in_x, Zsqr); | |
260 | ecp_nistz256_sub(Zsqr, in_x, Zsqr); | |
261 | ||
262 | ecp_nistz256_sqr_mont(res_y, S); | |
263 | ecp_nistz256_div_by_2(res_y, res_y); | |
264 | ||
265 | ecp_nistz256_mul_mont(M, M, Zsqr); | |
266 | ecp_nistz256_mul_by_3(M, M); | |
267 | ||
268 | ecp_nistz256_mul_mont(S, S, in_x); | |
269 | ecp_nistz256_mul_by_2(tmp0, S); | |
270 | ||
271 | ecp_nistz256_sqr_mont(res_x, M); | |
272 | ||
273 | ecp_nistz256_sub(res_x, res_x, tmp0); | |
274 | ecp_nistz256_sub(S, S, res_x); | |
275 | ||
276 | ecp_nistz256_mul_mont(S, S, M); | |
277 | ecp_nistz256_sub(res_y, S, res_y); | |
278 | } | |
279 | ||
280 | /* Point addition: r = a+b */ | |
20728adc AP |
281 | static void ecp_nistz256_point_add(P256_POINT *r, |
282 | const P256_POINT *a, const P256_POINT *b) | |
4d3fa06f AP |
283 | { |
284 | BN_ULONG U2[P256_LIMBS], S2[P256_LIMBS]; | |
285 | BN_ULONG U1[P256_LIMBS], S1[P256_LIMBS]; | |
286 | BN_ULONG Z1sqr[P256_LIMBS]; | |
287 | BN_ULONG Z2sqr[P256_LIMBS]; | |
288 | BN_ULONG H[P256_LIMBS], R[P256_LIMBS]; | |
289 | BN_ULONG Hsqr[P256_LIMBS]; | |
290 | BN_ULONG Rsqr[P256_LIMBS]; | |
291 | BN_ULONG Hcub[P256_LIMBS]; | |
292 | ||
293 | BN_ULONG res_x[P256_LIMBS]; | |
294 | BN_ULONG res_y[P256_LIMBS]; | |
295 | BN_ULONG res_z[P256_LIMBS]; | |
296 | ||
297 | BN_ULONG in1infty, in2infty; | |
298 | ||
299 | const BN_ULONG *in1_x = a->X; | |
300 | const BN_ULONG *in1_y = a->Y; | |
301 | const BN_ULONG *in1_z = a->Z; | |
302 | ||
303 | const BN_ULONG *in2_x = b->X; | |
304 | const BN_ULONG *in2_y = b->Y; | |
305 | const BN_ULONG *in2_z = b->Z; | |
306 | ||
307 | /* We encode infinity as (0,0), which is not on the curve, | |
308 | * so it is OK. */ | |
58d47cf0 AP |
309 | in1infty = (in1_x[0] | in1_x[1] | in1_x[2] | in1_x[3] | |
310 | in1_y[0] | in1_y[1] | in1_y[2] | in1_y[3]); | |
4d3fa06f | 311 | if (P256_LIMBS == 8) |
58d47cf0 AP |
312 | in1infty |= (in1_x[4] | in1_x[5] | in1_x[6] | in1_x[7] | |
313 | in1_y[4] | in1_y[5] | in1_y[6] | in1_y[7]); | |
4d3fa06f | 314 | |
58d47cf0 AP |
315 | in2infty = (in2_x[0] | in2_x[1] | in2_x[2] | in2_x[3] | |
316 | in2_y[0] | in2_y[1] | in2_y[2] | in2_y[3]); | |
4d3fa06f | 317 | if (P256_LIMBS == 8) |
58d47cf0 AP |
318 | in2infty |= (in2_x[4] | in2_x[5] | in2_x[6] | in2_x[7] | |
319 | in2_y[4] | in2_y[5] | in2_y[6] | in2_y[7]); | |
4d3fa06f AP |
320 | |
321 | in1infty = is_zero(in1infty); | |
322 | in2infty = is_zero(in2infty); | |
323 | ||
324 | ecp_nistz256_sqr_mont(Z2sqr, in2_z); /* Z2^2 */ | |
325 | ecp_nistz256_sqr_mont(Z1sqr, in1_z); /* Z1^2 */ | |
326 | ||
327 | ecp_nistz256_mul_mont(S1, Z2sqr, in2_z); /* S1 = Z2^3 */ | |
328 | ecp_nistz256_mul_mont(S2, Z1sqr, in1_z); /* S2 = Z1^3 */ | |
329 | ||
330 | ecp_nistz256_mul_mont(S1, S1, in1_y); /* S1 = Y1*Z2^3 */ | |
331 | ecp_nistz256_mul_mont(S2, S2, in2_y); /* S2 = Y2*Z1^3 */ | |
332 | ecp_nistz256_sub(R, S2, S1); /* R = S2 - S1 */ | |
333 | ||
334 | ecp_nistz256_mul_mont(U1, in1_x, Z2sqr); /* U1 = X1*Z2^2 */ | |
335 | ecp_nistz256_mul_mont(U2, in2_x, Z1sqr); /* U2 = X2*Z1^2 */ | |
336 | ecp_nistz256_sub(H, U2, U1); /* H = U2 - U1 */ | |
337 | ||
20728adc AP |
338 | /* |
339 | * This should not happen during sign/ecdh, so no constant time violation | |
340 | */ | |
4d3fa06f AP |
341 | if (is_equal(U1, U2) && !in1infty && !in2infty) { |
342 | if (is_equal(S1, S2)) { | |
343 | ecp_nistz256_point_double(r, a); | |
344 | return; | |
345 | } else { | |
346 | memset(r, 0, sizeof(*r)); | |
347 | return; | |
348 | } | |
349 | } | |
350 | ||
351 | ecp_nistz256_sqr_mont(Rsqr, R); /* R^2 */ | |
352 | ecp_nistz256_mul_mont(res_z, H, in1_z); /* Z3 = H*Z1*Z2 */ | |
353 | ecp_nistz256_sqr_mont(Hsqr, H); /* H^2 */ | |
354 | ecp_nistz256_mul_mont(res_z, res_z, in2_z); /* Z3 = H*Z1*Z2 */ | |
355 | ecp_nistz256_mul_mont(Hcub, Hsqr, H); /* H^3 */ | |
356 | ||
357 | ecp_nistz256_mul_mont(U2, U1, Hsqr); /* U1*H^2 */ | |
358 | ecp_nistz256_mul_by_2(Hsqr, U2); /* 2*U1*H^2 */ | |
359 | ||
360 | ecp_nistz256_sub(res_x, Rsqr, Hsqr); | |
361 | ecp_nistz256_sub(res_x, res_x, Hcub); | |
362 | ||
363 | ecp_nistz256_sub(res_y, U2, res_x); | |
364 | ||
365 | ecp_nistz256_mul_mont(S2, S1, Hcub); | |
366 | ecp_nistz256_mul_mont(res_y, R, res_y); | |
367 | ecp_nistz256_sub(res_y, res_y, S2); | |
368 | ||
369 | copy_conditional(res_x, in2_x, in1infty); | |
370 | copy_conditional(res_y, in2_y, in1infty); | |
371 | copy_conditional(res_z, in2_z, in1infty); | |
372 | ||
373 | copy_conditional(res_x, in1_x, in2infty); | |
374 | copy_conditional(res_y, in1_y, in2infty); | |
375 | copy_conditional(res_z, in1_z, in2infty); | |
376 | ||
377 | memcpy(r->X, res_x, sizeof(res_x)); | |
378 | memcpy(r->Y, res_y, sizeof(res_y)); | |
379 | memcpy(r->Z, res_z, sizeof(res_z)); | |
380 | } | |
381 | ||
382 | /* Point addition when b is known to be affine: r = a+b */ | |
58d47cf0 AP |
383 | static void ecp_nistz256_point_add_affine(P256_POINT *r, |
384 | const P256_POINT *a, | |
385 | const P256_POINT_AFFINE *b) | |
4d3fa06f AP |
386 | { |
387 | BN_ULONG U2[P256_LIMBS], S2[P256_LIMBS]; | |
388 | BN_ULONG Z1sqr[P256_LIMBS]; | |
389 | BN_ULONG H[P256_LIMBS], R[P256_LIMBS]; | |
390 | BN_ULONG Hsqr[P256_LIMBS]; | |
391 | BN_ULONG Rsqr[P256_LIMBS]; | |
392 | BN_ULONG Hcub[P256_LIMBS]; | |
393 | ||
394 | BN_ULONG res_x[P256_LIMBS]; | |
395 | BN_ULONG res_y[P256_LIMBS]; | |
396 | BN_ULONG res_z[P256_LIMBS]; | |
397 | ||
398 | BN_ULONG in1infty, in2infty; | |
399 | ||
400 | const BN_ULONG *in1_x = a->X; | |
401 | const BN_ULONG *in1_y = a->Y; | |
402 | const BN_ULONG *in1_z = a->Z; | |
403 | ||
404 | const BN_ULONG *in2_x = b->X; | |
405 | const BN_ULONG *in2_y = b->Y; | |
406 | ||
20728adc AP |
407 | /* |
408 | * In affine representation we encode infty as (0,0), which is not on the | |
409 | * curve, so it is OK | |
410 | */ | |
58d47cf0 AP |
411 | in1infty = (in1_x[0] | in1_x[1] | in1_x[2] | in1_x[3] | |
412 | in1_y[0] | in1_y[1] | in1_y[2] | in1_y[3]); | |
4d3fa06f | 413 | if (P256_LIMBS == 8) |
58d47cf0 AP |
414 | in1infty |= (in1_x[4] | in1_x[5] | in1_x[6] | in1_x[7] | |
415 | in1_y[4] | in1_y[5] | in1_y[6] | in1_y[7]); | |
4d3fa06f | 416 | |
58d47cf0 AP |
417 | in2infty = (in2_x[0] | in2_x[1] | in2_x[2] | in2_x[3] | |
418 | in2_y[0] | in2_y[1] | in2_y[2] | in2_y[3]); | |
4d3fa06f | 419 | if (P256_LIMBS == 8) |
58d47cf0 AP |
420 | in2infty |= (in2_x[4] | in2_x[5] | in2_x[6] | in2_x[7] | |
421 | in2_y[4] | in2_y[5] | in2_y[6] | in2_y[7]); | |
4d3fa06f AP |
422 | |
423 | in1infty = is_zero(in1infty); | |
424 | in2infty = is_zero(in2infty); | |
425 | ||
426 | ecp_nistz256_sqr_mont(Z1sqr, in1_z); /* Z1^2 */ | |
427 | ||
428 | ecp_nistz256_mul_mont(U2, in2_x, Z1sqr); /* U2 = X2*Z1^2 */ | |
429 | ecp_nistz256_sub(H, U2, in1_x); /* H = U2 - U1 */ | |
430 | ||
431 | ecp_nistz256_mul_mont(S2, Z1sqr, in1_z); /* S2 = Z1^3 */ | |
432 | ||
433 | ecp_nistz256_mul_mont(res_z, H, in1_z); /* Z3 = H*Z1*Z2 */ | |
434 | ||
435 | ecp_nistz256_mul_mont(S2, S2, in2_y); /* S2 = Y2*Z1^3 */ | |
436 | ecp_nistz256_sub(R, S2, in1_y); /* R = S2 - S1 */ | |
437 | ||
438 | ecp_nistz256_sqr_mont(Hsqr, H); /* H^2 */ | |
439 | ecp_nistz256_sqr_mont(Rsqr, R); /* R^2 */ | |
440 | ecp_nistz256_mul_mont(Hcub, Hsqr, H); /* H^3 */ | |
441 | ||
442 | ecp_nistz256_mul_mont(U2, in1_x, Hsqr); /* U1*H^2 */ | |
443 | ecp_nistz256_mul_by_2(Hsqr, U2); /* 2*U1*H^2 */ | |
444 | ||
445 | ecp_nistz256_sub(res_x, Rsqr, Hsqr); | |
446 | ecp_nistz256_sub(res_x, res_x, Hcub); | |
447 | ecp_nistz256_sub(H, U2, res_x); | |
448 | ||
449 | ecp_nistz256_mul_mont(S2, in1_y, Hcub); | |
450 | ecp_nistz256_mul_mont(H, H, R); | |
451 | ecp_nistz256_sub(res_y, H, S2); | |
452 | ||
453 | copy_conditional(res_x, in2_x, in1infty); | |
454 | copy_conditional(res_x, in1_x, in2infty); | |
455 | ||
456 | copy_conditional(res_y, in2_y, in1infty); | |
457 | copy_conditional(res_y, in1_y, in2infty); | |
458 | ||
459 | copy_conditional(res_z, ONE, in1infty); | |
460 | copy_conditional(res_z, in1_z, in2infty); | |
461 | ||
462 | memcpy(r->X, res_x, sizeof(res_x)); | |
463 | memcpy(r->Y, res_y, sizeof(res_y)); | |
464 | memcpy(r->Z, res_z, sizeof(res_z)); | |
465 | } | |
466 | #endif | |
467 | ||
468 | /* r = in^-1 mod p */ | |
469 | static void ecp_nistz256_mod_inverse(BN_ULONG r[P256_LIMBS], | |
470 | const BN_ULONG in[P256_LIMBS]) | |
471 | { | |
20728adc AP |
472 | /* |
473 | * The poly is ffffffff 00000001 00000000 00000000 00000000 ffffffff | |
474 | * ffffffff ffffffff We use FLT and used poly-2 as exponent | |
475 | */ | |
4d3fa06f AP |
476 | BN_ULONG p2[P256_LIMBS]; |
477 | BN_ULONG p4[P256_LIMBS]; | |
478 | BN_ULONG p8[P256_LIMBS]; | |
479 | BN_ULONG p16[P256_LIMBS]; | |
480 | BN_ULONG p32[P256_LIMBS]; | |
481 | BN_ULONG res[P256_LIMBS]; | |
482 | int i; | |
483 | ||
484 | ecp_nistz256_sqr_mont(res, in); | |
485 | ecp_nistz256_mul_mont(p2, res, in); /* 3*p */ | |
486 | ||
487 | ecp_nistz256_sqr_mont(res, p2); | |
488 | ecp_nistz256_sqr_mont(res, res); | |
489 | ecp_nistz256_mul_mont(p4, res, p2); /* f*p */ | |
490 | ||
491 | ecp_nistz256_sqr_mont(res, p4); | |
492 | ecp_nistz256_sqr_mont(res, res); | |
493 | ecp_nistz256_sqr_mont(res, res); | |
494 | ecp_nistz256_sqr_mont(res, res); | |
495 | ecp_nistz256_mul_mont(p8, res, p4); /* ff*p */ | |
496 | ||
497 | ecp_nistz256_sqr_mont(res, p8); | |
498 | for (i = 0; i < 7; i++) | |
499 | ecp_nistz256_sqr_mont(res, res); | |
500 | ecp_nistz256_mul_mont(p16, res, p8); /* ffff*p */ | |
501 | ||
502 | ecp_nistz256_sqr_mont(res, p16); | |
503 | for (i = 0; i < 15; i++) | |
504 | ecp_nistz256_sqr_mont(res, res); | |
505 | ecp_nistz256_mul_mont(p32, res, p16); /* ffffffff*p */ | |
506 | ||
507 | ecp_nistz256_sqr_mont(res, p32); | |
508 | for (i = 0; i < 31; i++) | |
509 | ecp_nistz256_sqr_mont(res, res); | |
510 | ecp_nistz256_mul_mont(res, res, in); | |
511 | ||
512 | for (i = 0; i < 32 * 4; i++) | |
513 | ecp_nistz256_sqr_mont(res, res); | |
514 | ecp_nistz256_mul_mont(res, res, p32); | |
515 | ||
516 | for (i = 0; i < 32; i++) | |
517 | ecp_nistz256_sqr_mont(res, res); | |
518 | ecp_nistz256_mul_mont(res, res, p32); | |
519 | ||
520 | for (i = 0; i < 16; i++) | |
521 | ecp_nistz256_sqr_mont(res, res); | |
522 | ecp_nistz256_mul_mont(res, res, p16); | |
523 | ||
524 | for (i = 0; i < 8; i++) | |
525 | ecp_nistz256_sqr_mont(res, res); | |
526 | ecp_nistz256_mul_mont(res, res, p8); | |
527 | ||
528 | ecp_nistz256_sqr_mont(res, res); | |
529 | ecp_nistz256_sqr_mont(res, res); | |
530 | ecp_nistz256_sqr_mont(res, res); | |
531 | ecp_nistz256_sqr_mont(res, res); | |
532 | ecp_nistz256_mul_mont(res, res, p4); | |
533 | ||
534 | ecp_nistz256_sqr_mont(res, res); | |
535 | ecp_nistz256_sqr_mont(res, res); | |
536 | ecp_nistz256_mul_mont(res, res, p2); | |
537 | ||
538 | ecp_nistz256_sqr_mont(res, res); | |
539 | ecp_nistz256_sqr_mont(res, res); | |
540 | ecp_nistz256_mul_mont(res, res, in); | |
541 | ||
542 | memcpy(r, res, sizeof(res)); | |
543 | } | |
544 | ||
20728adc AP |
545 | /* |
546 | * ecp_nistz256_bignum_to_field_elem copies the contents of |in| to |out| and | |
547 | * returns one if it fits. Otherwise it returns zero. | |
548 | */ | |
5956b110 EK |
549 | __owur static int ecp_nistz256_bignum_to_field_elem(BN_ULONG out[P256_LIMBS], |
550 | const BIGNUM *in) | |
4d3fa06f | 551 | { |
5784a521 | 552 | return bn_copy_words(out, in, P256_LIMBS); |
4d3fa06f AP |
553 | } |
554 | ||
555 | /* r = sum(scalar[i]*point[i]) */ | |
5956b110 EK |
556 | __owur static int ecp_nistz256_windowed_mul(const EC_GROUP *group, |
557 | P256_POINT *r, | |
558 | const BIGNUM **scalar, | |
559 | const EC_POINT **point, | |
560 | size_t num, BN_CTX *ctx) | |
4d3fa06f | 561 | { |
5afc296a | 562 | size_t i; |
a4d5269e | 563 | int j, ret = 0; |
49b05c7d | 564 | unsigned int idx; |
4d3fa06f AP |
565 | unsigned char (*p_str)[33] = NULL; |
566 | const unsigned int window_size = 5; | |
567 | const unsigned int mask = (1 << (window_size + 1)) - 1; | |
568 | unsigned int wvalue; | |
20728adc | 569 | P256_POINT *temp; /* place for 5 temporary points */ |
4d3fa06f | 570 | const BIGNUM **scalars = NULL; |
20728adc | 571 | P256_POINT (*table)[16] = NULL; |
4d3fa06f AP |
572 | void *table_storage = NULL; |
573 | ||
5afc296a AP |
574 | if ((num * 16 + 6) > OPENSSL_MALLOC_MAX_NELEMS(P256_POINT) |
575 | || (table_storage = | |
576 | OPENSSL_malloc((num * 16 + 5) * sizeof(P256_POINT) + 64)) == NULL | |
4d3fa06f AP |
577 | || (p_str = |
578 | OPENSSL_malloc(num * 33 * sizeof(unsigned char))) == NULL | |
579 | || (scalars = OPENSSL_malloc(num * sizeof(BIGNUM *))) == NULL) { | |
be07ae9b | 580 | ECerr(EC_F_ECP_NISTZ256_WINDOWED_MUL, ERR_R_MALLOC_FAILURE); |
4d3fa06f | 581 | goto err; |
4d3fa06f AP |
582 | } |
583 | ||
3ff08e1d | 584 | table = (void *)ALIGNPTR(table_storage, 64); |
20728adc | 585 | temp = (P256_POINT *)(table + num); |
3ff08e1d | 586 | |
4d3fa06f AP |
587 | for (i = 0; i < num; i++) { |
588 | P256_POINT *row = table[i]; | |
589 | ||
c028254b | 590 | /* This is an unusual input, we don't guarantee constant-timeness. */ |
4d3fa06f AP |
591 | if ((BN_num_bits(scalar[i]) > 256) || BN_is_negative(scalar[i])) { |
592 | BIGNUM *mod; | |
593 | ||
594 | if ((mod = BN_CTX_get(ctx)) == NULL) | |
595 | goto err; | |
5784a521 | 596 | if (!BN_nnmod(mod, scalar[i], group->order, ctx)) { |
be07ae9b | 597 | ECerr(EC_F_ECP_NISTZ256_WINDOWED_MUL, ERR_R_BN_LIB); |
4d3fa06f AP |
598 | goto err; |
599 | } | |
600 | scalars[i] = mod; | |
601 | } else | |
602 | scalars[i] = scalar[i]; | |
603 | ||
5784a521 MC |
604 | for (j = 0; j < bn_get_top(scalars[i]) * BN_BYTES; j += BN_BYTES) { |
605 | BN_ULONG d = bn_get_words(scalars[i])[j / BN_BYTES]; | |
4d3fa06f | 606 | |
5afc296a AP |
607 | p_str[i][j + 0] = (unsigned char)d; |
608 | p_str[i][j + 1] = (unsigned char)(d >> 8); | |
609 | p_str[i][j + 2] = (unsigned char)(d >> 16); | |
610 | p_str[i][j + 3] = (unsigned char)(d >>= 24); | |
4d3fa06f AP |
611 | if (BN_BYTES == 8) { |
612 | d >>= 8; | |
5afc296a AP |
613 | p_str[i][j + 4] = (unsigned char)d; |
614 | p_str[i][j + 5] = (unsigned char)(d >> 8); | |
615 | p_str[i][j + 6] = (unsigned char)(d >> 16); | |
616 | p_str[i][j + 7] = (unsigned char)(d >> 24); | |
4d3fa06f AP |
617 | } |
618 | } | |
619 | for (; j < 33; j++) | |
620 | p_str[i][j] = 0; | |
621 | ||
5784a521 MC |
622 | if (!ecp_nistz256_bignum_to_field_elem(temp[0].X, point[i]->X) |
623 | || !ecp_nistz256_bignum_to_field_elem(temp[0].Y, point[i]->Y) | |
624 | || !ecp_nistz256_bignum_to_field_elem(temp[0].Z, point[i]->Z)) { | |
58d47cf0 AP |
625 | ECerr(EC_F_ECP_NISTZ256_WINDOWED_MUL, |
626 | EC_R_COORDINATES_OUT_OF_RANGE); | |
4d3fa06f AP |
627 | goto err; |
628 | } | |
629 | ||
20728adc AP |
630 | /* |
631 | * row[0] is implicitly (0,0,0) (the point at infinity), therefore it | |
632 | * is not stored. All other values are actually stored with an offset | |
633 | * of -1 in table. | |
3ff08e1d AP |
634 | */ |
635 | ||
636 | ecp_nistz256_scatter_w5 (row, &temp[0], 1); | |
637 | ecp_nistz256_point_double(&temp[1], &temp[0]); /*1+1=2 */ | |
638 | ecp_nistz256_scatter_w5 (row, &temp[1], 2); | |
639 | ecp_nistz256_point_add (&temp[2], &temp[1], &temp[0]); /*2+1=3 */ | |
640 | ecp_nistz256_scatter_w5 (row, &temp[2], 3); | |
641 | ecp_nistz256_point_double(&temp[1], &temp[1]); /*2*2=4 */ | |
642 | ecp_nistz256_scatter_w5 (row, &temp[1], 4); | |
643 | ecp_nistz256_point_double(&temp[2], &temp[2]); /*2*3=6 */ | |
644 | ecp_nistz256_scatter_w5 (row, &temp[2], 6); | |
645 | ecp_nistz256_point_add (&temp[3], &temp[1], &temp[0]); /*4+1=5 */ | |
646 | ecp_nistz256_scatter_w5 (row, &temp[3], 5); | |
647 | ecp_nistz256_point_add (&temp[4], &temp[2], &temp[0]); /*6+1=7 */ | |
648 | ecp_nistz256_scatter_w5 (row, &temp[4], 7); | |
649 | ecp_nistz256_point_double(&temp[1], &temp[1]); /*2*4=8 */ | |
650 | ecp_nistz256_scatter_w5 (row, &temp[1], 8); | |
651 | ecp_nistz256_point_double(&temp[2], &temp[2]); /*2*6=12 */ | |
652 | ecp_nistz256_scatter_w5 (row, &temp[2], 12); | |
653 | ecp_nistz256_point_double(&temp[3], &temp[3]); /*2*5=10 */ | |
654 | ecp_nistz256_scatter_w5 (row, &temp[3], 10); | |
655 | ecp_nistz256_point_double(&temp[4], &temp[4]); /*2*7=14 */ | |
656 | ecp_nistz256_scatter_w5 (row, &temp[4], 14); | |
657 | ecp_nistz256_point_add (&temp[2], &temp[2], &temp[0]); /*12+1=13*/ | |
658 | ecp_nistz256_scatter_w5 (row, &temp[2], 13); | |
659 | ecp_nistz256_point_add (&temp[3], &temp[3], &temp[0]); /*10+1=11*/ | |
660 | ecp_nistz256_scatter_w5 (row, &temp[3], 11); | |
661 | ecp_nistz256_point_add (&temp[4], &temp[4], &temp[0]); /*14+1=15*/ | |
662 | ecp_nistz256_scatter_w5 (row, &temp[4], 15); | |
663 | ecp_nistz256_point_add (&temp[2], &temp[1], &temp[0]); /*8+1=9 */ | |
664 | ecp_nistz256_scatter_w5 (row, &temp[2], 9); | |
665 | ecp_nistz256_point_double(&temp[1], &temp[1]); /*2*8=16 */ | |
666 | ecp_nistz256_scatter_w5 (row, &temp[1], 16); | |
4d3fa06f AP |
667 | } |
668 | ||
49b05c7d | 669 | idx = 255; |
4d3fa06f | 670 | |
49b05c7d RS |
671 | wvalue = p_str[0][(idx - 1) / 8]; |
672 | wvalue = (wvalue >> ((idx - 1) % 8)) & mask; | |
4d3fa06f | 673 | |
3ff08e1d AP |
674 | /* |
675 | * We gather to temp[0], because we know it's position relative | |
676 | * to table | |
677 | */ | |
678 | ecp_nistz256_gather_w5(&temp[0], table[0], _booth_recode_w5(wvalue) >> 1); | |
679 | memcpy(r, &temp[0], sizeof(temp[0])); | |
4d3fa06f | 680 | |
49b05c7d RS |
681 | while (idx >= 5) { |
682 | for (i = (idx == 255 ? 1 : 0); i < num; i++) { | |
683 | unsigned int off = (idx - 1) / 8; | |
4d3fa06f AP |
684 | |
685 | wvalue = p_str[i][off] | p_str[i][off + 1] << 8; | |
49b05c7d | 686 | wvalue = (wvalue >> ((idx - 1) % 8)) & mask; |
4d3fa06f AP |
687 | |
688 | wvalue = _booth_recode_w5(wvalue); | |
689 | ||
3ff08e1d | 690 | ecp_nistz256_gather_w5(&temp[0], table[i], wvalue >> 1); |
4d3fa06f | 691 | |
3ff08e1d AP |
692 | ecp_nistz256_neg(temp[1].Y, temp[0].Y); |
693 | copy_conditional(temp[0].Y, temp[1].Y, (wvalue & 1)); | |
4d3fa06f | 694 | |
3ff08e1d | 695 | ecp_nistz256_point_add(r, r, &temp[0]); |
4d3fa06f AP |
696 | } |
697 | ||
49b05c7d | 698 | idx -= window_size; |
4d3fa06f AP |
699 | |
700 | ecp_nistz256_point_double(r, r); | |
701 | ecp_nistz256_point_double(r, r); | |
702 | ecp_nistz256_point_double(r, r); | |
703 | ecp_nistz256_point_double(r, r); | |
704 | ecp_nistz256_point_double(r, r); | |
705 | } | |
706 | ||
707 | /* Final window */ | |
708 | for (i = 0; i < num; i++) { | |
709 | wvalue = p_str[i][0]; | |
710 | wvalue = (wvalue << 1) & mask; | |
711 | ||
712 | wvalue = _booth_recode_w5(wvalue); | |
713 | ||
3ff08e1d | 714 | ecp_nistz256_gather_w5(&temp[0], table[i], wvalue >> 1); |
4d3fa06f | 715 | |
3ff08e1d AP |
716 | ecp_nistz256_neg(temp[1].Y, temp[0].Y); |
717 | copy_conditional(temp[0].Y, temp[1].Y, wvalue & 1); | |
4d3fa06f | 718 | |
3ff08e1d | 719 | ecp_nistz256_point_add(r, r, &temp[0]); |
4d3fa06f AP |
720 | } |
721 | ||
a4d5269e | 722 | ret = 1; |
58d47cf0 | 723 | err: |
4d3fa06f AP |
724 | if (table_storage) |
725 | OPENSSL_free(table_storage); | |
726 | if (p_str) | |
727 | OPENSSL_free(p_str); | |
728 | if (scalars) | |
729 | OPENSSL_free(scalars); | |
a4d5269e | 730 | return ret; |
4d3fa06f AP |
731 | } |
732 | ||
733 | /* Coordinates of G, for which we have precomputed tables */ | |
734 | const static BN_ULONG def_xG[P256_LIMBS] = { | |
735 | TOBN(0x79e730d4, 0x18a9143c), TOBN(0x75ba95fc, 0x5fedb601), | |
736 | TOBN(0x79fb732b, 0x77622510), TOBN(0x18905f76, 0xa53755c6) | |
737 | }; | |
738 | ||
739 | const static BN_ULONG def_yG[P256_LIMBS] = { | |
740 | TOBN(0xddf25357, 0xce95560a), TOBN(0x8b4ab8e4, 0xba19e45c), | |
741 | TOBN(0xd2e88688, 0xdd21f325), TOBN(0x8571ff18, 0x25885d85) | |
742 | }; | |
743 | ||
20728adc AP |
744 | /* |
745 | * ecp_nistz256_is_affine_G returns one if |generator| is the standard, P-256 | |
746 | * generator. | |
747 | */ | |
58d47cf0 | 748 | static int ecp_nistz256_is_affine_G(const EC_POINT *generator) |
4d3fa06f | 749 | { |
5784a521 MC |
750 | return (bn_get_top(generator->X) == P256_LIMBS) && |
751 | (bn_get_top(generator->Y) == P256_LIMBS) && | |
752 | (bn_get_top(generator->Z) == (P256_LIMBS - P256_LIMBS / 8)) && | |
753 | is_equal(bn_get_words(generator->X), def_xG) && | |
754 | is_equal(bn_get_words(generator->Y), def_yG) && | |
755 | is_one(bn_get_words(generator->Z)); | |
4d3fa06f AP |
756 | } |
757 | ||
5956b110 | 758 | __owur static int ecp_nistz256_mult_precompute(EC_GROUP *group, BN_CTX *ctx) |
4d3fa06f | 759 | { |
20728adc AP |
760 | /* |
761 | * We precompute a table for a Booth encoded exponent (wNAF) based | |
4d3fa06f | 762 | * computation. Each table holds 64 values for safe access, with an |
20728adc AP |
763 | * implicit value of infinity at index zero. We use window of size 7, and |
764 | * therefore require ceil(256/7) = 37 tables. | |
765 | */ | |
4d3fa06f AP |
766 | BIGNUM *order; |
767 | EC_POINT *P = NULL, *T = NULL; | |
768 | const EC_POINT *generator; | |
769 | EC_PRE_COMP *pre_comp; | |
53dd4ddf | 770 | BN_CTX *new_ctx = NULL; |
4d3fa06f AP |
771 | int i, j, k, ret = 0; |
772 | size_t w; | |
773 | ||
774 | PRECOMP256_ROW *preComputedTable = NULL; | |
775 | unsigned char *precomp_storage = NULL; | |
776 | ||
777 | /* if there is an old EC_PRE_COMP object, throw it away */ | |
be07ae9b AP |
778 | EC_EX_DATA_free_data(&group->extra_data, ecp_nistz256_pre_comp_dup, |
779 | ecp_nistz256_pre_comp_free, | |
780 | ecp_nistz256_pre_comp_clear_free); | |
4d3fa06f AP |
781 | |
782 | generator = EC_GROUP_get0_generator(group); | |
783 | if (generator == NULL) { | |
be07ae9b | 784 | ECerr(EC_F_ECP_NISTZ256_MULT_PRECOMPUTE, EC_R_UNDEFINED_GENERATOR); |
4d3fa06f AP |
785 | return 0; |
786 | } | |
787 | ||
788 | if (ecp_nistz256_is_affine_G(generator)) { | |
20728adc AP |
789 | /* |
790 | * No need to calculate tables for the standard generator because we | |
791 | * have them statically. | |
792 | */ | |
4d3fa06f AP |
793 | return 1; |
794 | } | |
795 | ||
be07ae9b | 796 | if ((pre_comp = ecp_nistz256_pre_comp_new(group)) == NULL) |
4d3fa06f AP |
797 | return 0; |
798 | ||
799 | if (ctx == NULL) { | |
53dd4ddf | 800 | ctx = new_ctx = BN_CTX_new(); |
4d3fa06f AP |
801 | if (ctx == NULL) |
802 | goto err; | |
803 | } | |
804 | ||
805 | BN_CTX_start(ctx); | |
806 | order = BN_CTX_get(ctx); | |
807 | ||
808 | if (order == NULL) | |
809 | goto err; | |
810 | ||
811 | if (!EC_GROUP_get_order(group, order, ctx)) | |
812 | goto err; | |
813 | ||
814 | if (BN_is_zero(order)) { | |
be07ae9b | 815 | ECerr(EC_F_ECP_NISTZ256_MULT_PRECOMPUTE, EC_R_UNKNOWN_ORDER); |
4d3fa06f AP |
816 | goto err; |
817 | } | |
818 | ||
819 | w = 7; | |
820 | ||
821 | if ((precomp_storage = | |
822 | OPENSSL_malloc(37 * 64 * sizeof(P256_POINT_AFFINE) + 64)) == NULL) { | |
be07ae9b | 823 | ECerr(EC_F_ECP_NISTZ256_MULT_PRECOMPUTE, ERR_R_MALLOC_FAILURE); |
4d3fa06f | 824 | goto err; |
4d3fa06f AP |
825 | } |
826 | ||
3ff08e1d AP |
827 | preComputedTable = (void *)ALIGNPTR(precomp_storage, 64); |
828 | ||
4d3fa06f AP |
829 | P = EC_POINT_new(group); |
830 | T = EC_POINT_new(group); | |
53dd4ddf EK |
831 | if (P == NULL || T == NULL) |
832 | goto err; | |
4d3fa06f | 833 | |
20728adc AP |
834 | /* |
835 | * The zero entry is implicitly infinity, and we skip it, storing other | |
836 | * values with -1 offset. | |
837 | */ | |
53dd4ddf EK |
838 | if (!EC_POINT_copy(T, generator)) |
839 | goto err; | |
4d3fa06f AP |
840 | |
841 | for (k = 0; k < 64; k++) { | |
53dd4ddf EK |
842 | if (!EC_POINT_copy(P, T)) |
843 | goto err; | |
4d3fa06f | 844 | for (j = 0; j < 37; j++) { |
3ff08e1d | 845 | P256_POINT_AFFINE temp; |
20728adc | 846 | /* |
6038354c | 847 | * It would be faster to use EC_POINTs_make_affine and |
20728adc AP |
848 | * make multiple points affine at the same time. |
849 | */ | |
6038354c EK |
850 | if (!EC_POINT_make_affine(group, P, ctx)) |
851 | goto err; | |
852 | if (!ecp_nistz256_bignum_to_field_elem(temp.X, P->X) || | |
853 | !ecp_nistz256_bignum_to_field_elem(temp.Y, P->Y)) { | |
854 | ECerr(EC_F_ECP_NISTZ256_MULT_PRECOMPUTE, | |
855 | EC_R_COORDINATES_OUT_OF_RANGE); | |
856 | goto err; | |
857 | } | |
3ff08e1d | 858 | ecp_nistz256_scatter_w7(preComputedTable[j], &temp, k); |
6038354c EK |
859 | for (i = 0; i < 7; i++) { |
860 | if (!EC_POINT_dbl(group, P, P, ctx)) | |
861 | goto err; | |
862 | } | |
4d3fa06f | 863 | } |
6038354c EK |
864 | if (!EC_POINT_add(group, T, T, generator, ctx)) |
865 | goto err; | |
4d3fa06f AP |
866 | } |
867 | ||
868 | pre_comp->group = group; | |
869 | pre_comp->w = w; | |
870 | pre_comp->precomp = preComputedTable; | |
871 | pre_comp->precomp_storage = precomp_storage; | |
872 | ||
873 | precomp_storage = NULL; | |
874 | ||
875 | if (!EC_EX_DATA_set_data(&group->extra_data, pre_comp, | |
be07ae9b AP |
876 | ecp_nistz256_pre_comp_dup, |
877 | ecp_nistz256_pre_comp_free, | |
878 | ecp_nistz256_pre_comp_clear_free)) { | |
4d3fa06f AP |
879 | goto err; |
880 | } | |
881 | ||
882 | pre_comp = NULL; | |
883 | ||
884 | ret = 1; | |
885 | ||
58d47cf0 | 886 | err: |
4d3fa06f AP |
887 | if (ctx != NULL) |
888 | BN_CTX_end(ctx); | |
53dd4ddf EK |
889 | BN_CTX_free(new_ctx); |
890 | ||
e0e920b1 | 891 | ecp_nistz256_pre_comp_free(pre_comp); |
4d3fa06f AP |
892 | if (precomp_storage) |
893 | OPENSSL_free(precomp_storage); | |
8fdc3734 RS |
894 | EC_POINT_free(P); |
895 | EC_POINT_free(T); | |
4d3fa06f AP |
896 | return ret; |
897 | } | |
898 | ||
899 | /* | |
900 | * Note that by default ECP_NISTZ256_AVX2 is undefined. While it's great | |
901 | * code processing 4 points in parallel, corresponding serial operation | |
902 | * is several times slower, because it uses 29x29=58-bit multiplication | |
903 | * as opposite to 64x64=128-bit in integer-only scalar case. As result | |
904 | * it doesn't provide *significant* performance improvement. Note that | |
905 | * just defining ECP_NISTZ256_AVX2 is not sufficient to make it work, | |
906 | * you'd need to compile even asm/ecp_nistz256-avx.pl module. | |
907 | */ | |
908 | #if defined(ECP_NISTZ256_AVX2) | |
3ff08e1d | 909 | # if !(defined(__x86_64) || defined(__x86_64__) || \ |
4d3fa06f AP |
910 | defined(_M_AMD64) || defined(_MX64)) || \ |
911 | !(defined(__GNUC__) || defined(_MSC_VER)) /* this is for ALIGN32 */ | |
912 | # undef ECP_NISTZ256_AVX2 | |
913 | # else | |
914 | /* Constant time access, loading four values, from four consecutive tables */ | |
58d47cf0 AP |
915 | void ecp_nistz256_avx2_multi_gather_w7(void *result, const void *in, |
916 | int index0, int index1, int index2, | |
917 | int index3); | |
4d3fa06f AP |
918 | void ecp_nistz256_avx2_transpose_convert(void *RESULTx4, const void *in); |
919 | void ecp_nistz256_avx2_convert_transpose_back(void *result, const void *Ax4); | |
920 | void ecp_nistz256_avx2_point_add_affine_x4(void *RESULTx4, const void *Ax4, | |
921 | const void *Bx4); | |
922 | void ecp_nistz256_avx2_point_add_affines_x4(void *RESULTx4, const void *Ax4, | |
923 | const void *Bx4); | |
924 | void ecp_nistz256_avx2_to_mont(void *RESULTx4, const void *Ax4); | |
925 | void ecp_nistz256_avx2_from_mont(void *RESULTx4, const void *Ax4); | |
926 | void ecp_nistz256_avx2_set1(void *RESULTx4); | |
927 | int ecp_nistz_avx2_eligible(void); | |
928 | ||
929 | static void booth_recode_w7(unsigned char *sign, | |
930 | unsigned char *digit, unsigned char in) | |
931 | { | |
932 | unsigned char s, d; | |
933 | ||
934 | s = ~((in >> 7) - 1); | |
935 | d = (1 << 8) - in - 1; | |
936 | d = (d & s) | (in & ~s); | |
937 | d = (d >> 1) + (d & 1); | |
938 | ||
939 | *sign = s & 1; | |
940 | *digit = d; | |
941 | } | |
942 | ||
20728adc AP |
943 | /* |
944 | * ecp_nistz256_avx2_mul_g performs multiplication by G, using only the | |
4d3fa06f | 945 | * precomputed table. It does 4 affine point additions in parallel, |
20728adc AP |
946 | * significantly speeding up point multiplication for a fixed value. |
947 | */ | |
58d47cf0 | 948 | static void ecp_nistz256_avx2_mul_g(P256_POINT *r, |
4d3fa06f | 949 | unsigned char p_str[33], |
58d47cf0 | 950 | const P256_POINT_AFFINE(*preComputedTable)[64]) |
4d3fa06f AP |
951 | { |
952 | const unsigned int window_size = 7; | |
953 | const unsigned int mask = (1 << (window_size + 1)) - 1; | |
954 | unsigned int wvalue; | |
955 | /* Using 4 windows at a time */ | |
956 | unsigned char sign0, digit0; | |
957 | unsigned char sign1, digit1; | |
958 | unsigned char sign2, digit2; | |
959 | unsigned char sign3, digit3; | |
49b05c7d | 960 | unsigned int idx = 0; |
4d3fa06f AP |
961 | BN_ULONG tmp[P256_LIMBS]; |
962 | int i; | |
963 | ||
964 | ALIGN32 BN_ULONG aX4[4 * 9 * 3] = { 0 }; | |
965 | ALIGN32 BN_ULONG bX4[4 * 9 * 2] = { 0 }; | |
3ff08e1d AP |
966 | ALIGN32 P256_POINT_AFFINE point_arr[4]; |
967 | ALIGN32 P256_POINT res_point_arr[4]; | |
4d3fa06f AP |
968 | |
969 | /* Initial four windows */ | |
970 | wvalue = *((u16 *) & p_str[0]); | |
971 | wvalue = (wvalue << 1) & mask; | |
49b05c7d | 972 | idx += window_size; |
4d3fa06f | 973 | booth_recode_w7(&sign0, &digit0, wvalue); |
49b05c7d RS |
974 | wvalue = *((u16 *) & p_str[(idx - 1) / 8]); |
975 | wvalue = (wvalue >> ((idx - 1) % 8)) & mask; | |
976 | idx += window_size; | |
4d3fa06f | 977 | booth_recode_w7(&sign1, &digit1, wvalue); |
49b05c7d RS |
978 | wvalue = *((u16 *) & p_str[(idx - 1) / 8]); |
979 | wvalue = (wvalue >> ((idx - 1) % 8)) & mask; | |
980 | idx += window_size; | |
4d3fa06f | 981 | booth_recode_w7(&sign2, &digit2, wvalue); |
49b05c7d RS |
982 | wvalue = *((u16 *) & p_str[(idx - 1) / 8]); |
983 | wvalue = (wvalue >> ((idx - 1) % 8)) & mask; | |
984 | idx += window_size; | |
4d3fa06f AP |
985 | booth_recode_w7(&sign3, &digit3, wvalue); |
986 | ||
3ff08e1d | 987 | ecp_nistz256_avx2_multi_gather_w7(point_arr, preComputedTable[0], |
4d3fa06f AP |
988 | digit0, digit1, digit2, digit3); |
989 | ||
990 | ecp_nistz256_neg(tmp, point_arr[0].Y); | |
991 | copy_conditional(point_arr[0].Y, tmp, sign0); | |
992 | ecp_nistz256_neg(tmp, point_arr[1].Y); | |
993 | copy_conditional(point_arr[1].Y, tmp, sign1); | |
994 | ecp_nistz256_neg(tmp, point_arr[2].Y); | |
995 | copy_conditional(point_arr[2].Y, tmp, sign2); | |
996 | ecp_nistz256_neg(tmp, point_arr[3].Y); | |
997 | copy_conditional(point_arr[3].Y, tmp, sign3); | |
998 | ||
999 | ecp_nistz256_avx2_transpose_convert(aX4, point_arr); | |
1000 | ecp_nistz256_avx2_to_mont(aX4, aX4); | |
1001 | ecp_nistz256_avx2_to_mont(&aX4[4 * 9], &aX4[4 * 9]); | |
1002 | ecp_nistz256_avx2_set1(&aX4[4 * 9 * 2]); | |
1003 | ||
49b05c7d RS |
1004 | wvalue = *((u16 *) & p_str[(idx - 1) / 8]); |
1005 | wvalue = (wvalue >> ((idx - 1) % 8)) & mask; | |
1006 | idx += window_size; | |
4d3fa06f | 1007 | booth_recode_w7(&sign0, &digit0, wvalue); |
49b05c7d RS |
1008 | wvalue = *((u16 *) & p_str[(idx - 1) / 8]); |
1009 | wvalue = (wvalue >> ((idx - 1) % 8)) & mask; | |
1010 | idx += window_size; | |
4d3fa06f | 1011 | booth_recode_w7(&sign1, &digit1, wvalue); |
49b05c7d RS |
1012 | wvalue = *((u16 *) & p_str[(idx - 1) / 8]); |
1013 | wvalue = (wvalue >> ((idx - 1) % 8)) & mask; | |
1014 | idx += window_size; | |
4d3fa06f | 1015 | booth_recode_w7(&sign2, &digit2, wvalue); |
49b05c7d RS |
1016 | wvalue = *((u16 *) & p_str[(idx - 1) / 8]); |
1017 | wvalue = (wvalue >> ((idx - 1) % 8)) & mask; | |
1018 | idx += window_size; | |
4d3fa06f AP |
1019 | booth_recode_w7(&sign3, &digit3, wvalue); |
1020 | ||
3ff08e1d | 1021 | ecp_nistz256_avx2_multi_gather_w7(point_arr, preComputedTable[4 * 1], |
4d3fa06f AP |
1022 | digit0, digit1, digit2, digit3); |
1023 | ||
1024 | ecp_nistz256_neg(tmp, point_arr[0].Y); | |
1025 | copy_conditional(point_arr[0].Y, tmp, sign0); | |
1026 | ecp_nistz256_neg(tmp, point_arr[1].Y); | |
1027 | copy_conditional(point_arr[1].Y, tmp, sign1); | |
1028 | ecp_nistz256_neg(tmp, point_arr[2].Y); | |
1029 | copy_conditional(point_arr[2].Y, tmp, sign2); | |
1030 | ecp_nistz256_neg(tmp, point_arr[3].Y); | |
1031 | copy_conditional(point_arr[3].Y, tmp, sign3); | |
1032 | ||
1033 | ecp_nistz256_avx2_transpose_convert(bX4, point_arr); | |
1034 | ecp_nistz256_avx2_to_mont(bX4, bX4); | |
1035 | ecp_nistz256_avx2_to_mont(&bX4[4 * 9], &bX4[4 * 9]); | |
1036 | /* Optimized when both inputs are affine */ | |
1037 | ecp_nistz256_avx2_point_add_affines_x4(aX4, aX4, bX4); | |
1038 | ||
1039 | for (i = 2; i < 9; i++) { | |
49b05c7d RS |
1040 | wvalue = *((u16 *) & p_str[(idx - 1) / 8]); |
1041 | wvalue = (wvalue >> ((idx - 1) % 8)) & mask; | |
1042 | idx += window_size; | |
4d3fa06f | 1043 | booth_recode_w7(&sign0, &digit0, wvalue); |
49b05c7d RS |
1044 | wvalue = *((u16 *) & p_str[(idx - 1) / 8]); |
1045 | wvalue = (wvalue >> ((idx - 1) % 8)) & mask; | |
1046 | idx += window_size; | |
4d3fa06f | 1047 | booth_recode_w7(&sign1, &digit1, wvalue); |
49b05c7d RS |
1048 | wvalue = *((u16 *) & p_str[(idx - 1) / 8]); |
1049 | wvalue = (wvalue >> ((idx - 1) % 8)) & mask; | |
1050 | idx += window_size; | |
4d3fa06f | 1051 | booth_recode_w7(&sign2, &digit2, wvalue); |
49b05c7d RS |
1052 | wvalue = *((u16 *) & p_str[(idx - 1) / 8]); |
1053 | wvalue = (wvalue >> ((idx - 1) % 8)) & mask; | |
1054 | idx += window_size; | |
4d3fa06f AP |
1055 | booth_recode_w7(&sign3, &digit3, wvalue); |
1056 | ||
3ff08e1d | 1057 | ecp_nistz256_avx2_multi_gather_w7(point_arr, |
4d3fa06f AP |
1058 | preComputedTable[4 * i], |
1059 | digit0, digit1, digit2, digit3); | |
1060 | ||
1061 | ecp_nistz256_neg(tmp, point_arr[0].Y); | |
1062 | copy_conditional(point_arr[0].Y, tmp, sign0); | |
1063 | ecp_nistz256_neg(tmp, point_arr[1].Y); | |
1064 | copy_conditional(point_arr[1].Y, tmp, sign1); | |
1065 | ecp_nistz256_neg(tmp, point_arr[2].Y); | |
1066 | copy_conditional(point_arr[2].Y, tmp, sign2); | |
1067 | ecp_nistz256_neg(tmp, point_arr[3].Y); | |
1068 | copy_conditional(point_arr[3].Y, tmp, sign3); | |
1069 | ||
1070 | ecp_nistz256_avx2_transpose_convert(bX4, point_arr); | |
1071 | ecp_nistz256_avx2_to_mont(bX4, bX4); | |
1072 | ecp_nistz256_avx2_to_mont(&bX4[4 * 9], &bX4[4 * 9]); | |
1073 | ||
1074 | ecp_nistz256_avx2_point_add_affine_x4(aX4, aX4, bX4); | |
1075 | } | |
1076 | ||
1077 | ecp_nistz256_avx2_from_mont(&aX4[4 * 9 * 0], &aX4[4 * 9 * 0]); | |
1078 | ecp_nistz256_avx2_from_mont(&aX4[4 * 9 * 1], &aX4[4 * 9 * 1]); | |
1079 | ecp_nistz256_avx2_from_mont(&aX4[4 * 9 * 2], &aX4[4 * 9 * 2]); | |
1080 | ||
1081 | ecp_nistz256_avx2_convert_transpose_back(res_point_arr, aX4); | |
1082 | /* Last window is performed serially */ | |
49b05c7d RS |
1083 | wvalue = *((u16 *) & p_str[(idx - 1) / 8]); |
1084 | wvalue = (wvalue >> ((idx - 1) % 8)) & mask; | |
4d3fa06f | 1085 | booth_recode_w7(&sign0, &digit0, wvalue); |
58d47cf0 AP |
1086 | ecp_nistz256_gather_w7((P256_POINT_AFFINE *)r, |
1087 | preComputedTable[36], digit0); | |
4d3fa06f AP |
1088 | ecp_nistz256_neg(tmp, r->Y); |
1089 | copy_conditional(r->Y, tmp, sign0); | |
1090 | memcpy(r->Z, ONE, sizeof(ONE)); | |
1091 | /* Sum the four windows */ | |
1092 | ecp_nistz256_point_add(r, r, &res_point_arr[0]); | |
1093 | ecp_nistz256_point_add(r, r, &res_point_arr[1]); | |
1094 | ecp_nistz256_point_add(r, r, &res_point_arr[2]); | |
1095 | ecp_nistz256_point_add(r, r, &res_point_arr[3]); | |
1096 | } | |
1097 | # endif | |
1098 | #endif | |
1099 | ||
5956b110 EK |
1100 | __owur static int ecp_nistz256_set_from_affine(EC_POINT *out, const EC_GROUP *group, |
1101 | const P256_POINT_AFFINE *in, | |
1102 | BN_CTX *ctx) | |
4d3fa06f | 1103 | { |
5784a521 | 1104 | BIGNUM *x, *y; |
4d3fa06f AP |
1105 | BN_ULONG d_x[P256_LIMBS], d_y[P256_LIMBS]; |
1106 | int ret = 0; | |
1107 | ||
5784a521 | 1108 | x = BN_new(); |
58d47cf0 | 1109 | if (!x) |
5784a521 MC |
1110 | return 0; |
1111 | y = BN_new(); | |
58d47cf0 | 1112 | if (!y) { |
5784a521 MC |
1113 | BN_free(x); |
1114 | return 0; | |
1115 | } | |
4d3fa06f | 1116 | memcpy(d_x, in->X, sizeof(d_x)); |
5784a521 | 1117 | bn_set_static_words(x, d_x, P256_LIMBS); |
4d3fa06f AP |
1118 | |
1119 | memcpy(d_y, in->Y, sizeof(d_y)); | |
5784a521 MC |
1120 | bn_set_static_words(y, d_y, P256_LIMBS); |
1121 | ||
1122 | ret = EC_POINT_set_affine_coordinates_GFp(group, out, x, y, ctx); | |
4d3fa06f | 1123 | |
58d47cf0 AP |
1124 | if (x) |
1125 | BN_free(x); | |
1126 | if (y) | |
1127 | BN_free(y); | |
4d3fa06f AP |
1128 | |
1129 | return ret; | |
1130 | } | |
1131 | ||
1132 | /* r = scalar*G + sum(scalars[i]*points[i]) */ | |
5956b110 EK |
1133 | __owur static int ecp_nistz256_points_mul(const EC_GROUP *group, |
1134 | EC_POINT *r, | |
1135 | const BIGNUM *scalar, | |
1136 | size_t num, | |
1137 | const EC_POINT *points[], | |
1138 | const BIGNUM *scalars[], BN_CTX *ctx) | |
4d3fa06f AP |
1139 | { |
1140 | int i = 0, ret = 0, no_precomp_for_generator = 0, p_is_infinity = 0; | |
16e5b45f | 1141 | size_t j; |
4d3fa06f AP |
1142 | unsigned char p_str[33] = { 0 }; |
1143 | const PRECOMP256_ROW *preComputedTable = NULL; | |
1144 | const EC_PRE_COMP *pre_comp = NULL; | |
1145 | const EC_POINT *generator = NULL; | |
e22d2199 | 1146 | BN_CTX *new_ctx = NULL; |
a4d5269e EK |
1147 | const BIGNUM **new_scalars = NULL; |
1148 | const EC_POINT **new_points = NULL; | |
49b05c7d | 1149 | unsigned int idx = 0; |
4d3fa06f AP |
1150 | const unsigned int window_size = 7; |
1151 | const unsigned int mask = (1 << (window_size + 1)) - 1; | |
1152 | unsigned int wvalue; | |
1153 | ALIGN32 union { | |
1154 | P256_POINT p; | |
1155 | P256_POINT_AFFINE a; | |
1156 | } t, p; | |
1157 | BIGNUM *tmp_scalar; | |
1158 | ||
58d47cf0 | 1159 | if ((num + 1) == 0 || (num + 1) > OPENSSL_MALLOC_MAX_NELEMS(void *)) { |
3ff08e1d AP |
1160 | ECerr(EC_F_ECP_NISTZ256_POINTS_MUL, ERR_R_MALLOC_FAILURE); |
1161 | return 0; | |
1162 | } | |
1163 | ||
4d3fa06f | 1164 | if (group->meth != r->meth) { |
be07ae9b | 1165 | ECerr(EC_F_ECP_NISTZ256_POINTS_MUL, EC_R_INCOMPATIBLE_OBJECTS); |
4d3fa06f AP |
1166 | return 0; |
1167 | } | |
e22d2199 | 1168 | |
4d3fa06f AP |
1169 | if ((scalar == NULL) && (num == 0)) |
1170 | return EC_POINT_set_to_infinity(group, r); | |
1171 | ||
16e5b45f DSH |
1172 | for (j = 0; j < num; j++) { |
1173 | if (group->meth != points[j]->meth) { | |
be07ae9b | 1174 | ECerr(EC_F_ECP_NISTZ256_POINTS_MUL, EC_R_INCOMPATIBLE_OBJECTS); |
4d3fa06f AP |
1175 | return 0; |
1176 | } | |
1177 | } | |
1178 | ||
e22d2199 EK |
1179 | if (ctx == NULL) { |
1180 | ctx = new_ctx = BN_CTX_new(); | |
1181 | if (ctx == NULL) | |
1182 | goto err; | |
1183 | } | |
1184 | ||
1185 | BN_CTX_start(ctx); | |
4d3fa06f AP |
1186 | |
1187 | if (scalar) { | |
1188 | generator = EC_GROUP_get0_generator(group); | |
1189 | if (generator == NULL) { | |
be07ae9b | 1190 | ECerr(EC_F_ECP_NISTZ256_POINTS_MUL, EC_R_UNDEFINED_GENERATOR); |
4d3fa06f AP |
1191 | goto err; |
1192 | } | |
1193 | ||
1194 | /* look if we can use precomputed multiples of generator */ | |
1195 | pre_comp = | |
be07ae9b AP |
1196 | EC_EX_DATA_get_data(group->extra_data, ecp_nistz256_pre_comp_dup, |
1197 | ecp_nistz256_pre_comp_free, | |
1198 | ecp_nistz256_pre_comp_clear_free); | |
4d3fa06f AP |
1199 | |
1200 | if (pre_comp) { | |
20728adc AP |
1201 | /* |
1202 | * If there is a precomputed table for the generator, check that | |
1203 | * it was generated with the same generator. | |
1204 | */ | |
4d3fa06f AP |
1205 | EC_POINT *pre_comp_generator = EC_POINT_new(group); |
1206 | if (pre_comp_generator == NULL) | |
1207 | goto err; | |
1208 | ||
3ff08e1d AP |
1209 | if (!ecp_nistz256_set_from_affine(pre_comp_generator, |
1210 | group, pre_comp->precomp[0], | |
e22d2199 EK |
1211 | ctx)) { |
1212 | EC_POINT_free(pre_comp_generator); | |
4d3fa06f | 1213 | goto err; |
e22d2199 | 1214 | } |
4d3fa06f AP |
1215 | |
1216 | if (0 == EC_POINT_cmp(group, generator, pre_comp_generator, ctx)) | |
1217 | preComputedTable = (const PRECOMP256_ROW *)pre_comp->precomp; | |
1218 | ||
1219 | EC_POINT_free(pre_comp_generator); | |
1220 | } | |
1221 | ||
1222 | if (preComputedTable == NULL && ecp_nistz256_is_affine_G(generator)) { | |
20728adc AP |
1223 | /* |
1224 | * If there is no precomputed data, but the generator is the | |
1225 | * default, a hardcoded table of precomputed data is used. This | |
1226 | * is because applications, such as Apache, do not use | |
1227 | * EC_KEY_precompute_mult. | |
1228 | */ | |
3ff08e1d | 1229 | preComputedTable = ecp_nistz256_precomputed; |
4d3fa06f AP |
1230 | } |
1231 | ||
1232 | if (preComputedTable) { | |
1233 | if ((BN_num_bits(scalar) > 256) | |
1234 | || BN_is_negative(scalar)) { | |
1235 | if ((tmp_scalar = BN_CTX_get(ctx)) == NULL) | |
1236 | goto err; | |
1237 | ||
5784a521 | 1238 | if (!BN_nnmod(tmp_scalar, scalar, group->order, ctx)) { |
be07ae9b | 1239 | ECerr(EC_F_ECP_NISTZ256_POINTS_MUL, ERR_R_BN_LIB); |
4d3fa06f AP |
1240 | goto err; |
1241 | } | |
1242 | scalar = tmp_scalar; | |
1243 | } | |
1244 | ||
5784a521 MC |
1245 | for (i = 0; i < bn_get_top(scalar) * BN_BYTES; i += BN_BYTES) { |
1246 | BN_ULONG d = bn_get_words(scalar)[i / BN_BYTES]; | |
4d3fa06f | 1247 | |
5afc296a AP |
1248 | p_str[i + 0] = (unsigned char)d; |
1249 | p_str[i + 1] = (unsigned char)(d >> 8); | |
1250 | p_str[i + 2] = (unsigned char)(d >> 16); | |
1251 | p_str[i + 3] = (unsigned char)(d >>= 24); | |
4d3fa06f AP |
1252 | if (BN_BYTES == 8) { |
1253 | d >>= 8; | |
5afc296a AP |
1254 | p_str[i + 4] = (unsigned char)d; |
1255 | p_str[i + 5] = (unsigned char)(d >> 8); | |
1256 | p_str[i + 6] = (unsigned char)(d >> 16); | |
1257 | p_str[i + 7] = (unsigned char)(d >> 24); | |
4d3fa06f AP |
1258 | } |
1259 | } | |
1260 | ||
1261 | for (; i < 33; i++) | |
1262 | p_str[i] = 0; | |
1263 | ||
1264 | #if defined(ECP_NISTZ256_AVX2) | |
1265 | if (ecp_nistz_avx2_eligible()) { | |
1266 | ecp_nistz256_avx2_mul_g(&p.p, p_str, preComputedTable); | |
1267 | } else | |
1268 | #endif | |
1269 | { | |
1270 | /* First window */ | |
1271 | wvalue = (p_str[0] << 1) & mask; | |
49b05c7d | 1272 | idx += window_size; |
4d3fa06f AP |
1273 | |
1274 | wvalue = _booth_recode_w7(wvalue); | |
1275 | ||
58d47cf0 AP |
1276 | ecp_nistz256_gather_w7(&p.a, preComputedTable[0], |
1277 | wvalue >> 1); | |
4d3fa06f AP |
1278 | |
1279 | ecp_nistz256_neg(p.p.Z, p.p.Y); | |
1280 | copy_conditional(p.p.Y, p.p.Z, wvalue & 1); | |
1281 | ||
1282 | memcpy(p.p.Z, ONE, sizeof(ONE)); | |
1283 | ||
1284 | for (i = 1; i < 37; i++) { | |
49b05c7d | 1285 | unsigned int off = (idx - 1) / 8; |
4d3fa06f | 1286 | wvalue = p_str[off] | p_str[off + 1] << 8; |
49b05c7d RS |
1287 | wvalue = (wvalue >> ((idx - 1) % 8)) & mask; |
1288 | idx += window_size; | |
4d3fa06f AP |
1289 | |
1290 | wvalue = _booth_recode_w7(wvalue); | |
1291 | ||
3ff08e1d | 1292 | ecp_nistz256_gather_w7(&t.a, |
4d3fa06f AP |
1293 | preComputedTable[i], wvalue >> 1); |
1294 | ||
1295 | ecp_nistz256_neg(t.p.Z, t.a.Y); | |
1296 | copy_conditional(t.a.Y, t.p.Z, wvalue & 1); | |
1297 | ||
1298 | ecp_nistz256_point_add_affine(&p.p, &p.p, &t.a); | |
1299 | } | |
1300 | } | |
1301 | } else { | |
1302 | p_is_infinity = 1; | |
1303 | no_precomp_for_generator = 1; | |
1304 | } | |
1305 | } else | |
1306 | p_is_infinity = 1; | |
1307 | ||
1308 | if (no_precomp_for_generator) { | |
20728adc AP |
1309 | /* |
1310 | * Without a precomputed table for the generator, it has to be | |
1311 | * handled like a normal point. | |
1312 | */ | |
4d3fa06f AP |
1313 | new_scalars = OPENSSL_malloc((num + 1) * sizeof(BIGNUM *)); |
1314 | if (!new_scalars) { | |
be07ae9b | 1315 | ECerr(EC_F_ECP_NISTZ256_POINTS_MUL, ERR_R_MALLOC_FAILURE); |
e22d2199 | 1316 | goto err; |
4d3fa06f AP |
1317 | } |
1318 | ||
1319 | new_points = OPENSSL_malloc((num + 1) * sizeof(EC_POINT *)); | |
1320 | if (!new_points) { | |
be07ae9b | 1321 | ECerr(EC_F_ECP_NISTZ256_POINTS_MUL, ERR_R_MALLOC_FAILURE); |
e22d2199 | 1322 | goto err; |
4d3fa06f AP |
1323 | } |
1324 | ||
1325 | memcpy(new_scalars, scalars, num * sizeof(BIGNUM *)); | |
1326 | new_scalars[num] = scalar; | |
1327 | memcpy(new_points, points, num * sizeof(EC_POINT *)); | |
1328 | new_points[num] = generator; | |
1329 | ||
1330 | scalars = new_scalars; | |
1331 | points = new_points; | |
1332 | num++; | |
1333 | } | |
1334 | ||
1335 | if (num) { | |
1336 | P256_POINT *out = &t.p; | |
1337 | if (p_is_infinity) | |
1338 | out = &p.p; | |
1339 | ||
a4d5269e EK |
1340 | if (!ecp_nistz256_windowed_mul(group, out, scalars, points, num, ctx)) |
1341 | goto err; | |
4d3fa06f AP |
1342 | |
1343 | if (!p_is_infinity) | |
1344 | ecp_nistz256_point_add(&p.p, &p.p, out); | |
1345 | } | |
1346 | ||
c028254b | 1347 | /* Not constant-time, but we're only operating on the public output. */ |
e22d2199 EK |
1348 | if (!bn_set_words(r->X, p.p.X, P256_LIMBS) || |
1349 | !bn_set_words(r->Y, p.p.Y, P256_LIMBS) || | |
1350 | !bn_set_words(r->Z, p.p.Z, P256_LIMBS)) { | |
1351 | goto err; | |
1352 | } | |
4446044a | 1353 | r->Z_is_one = is_one(p.p.Z) & 1; |
4d3fa06f AP |
1354 | |
1355 | ret = 1; | |
1356 | ||
e22d2199 EK |
1357 | err: |
1358 | if (ctx) | |
1359 | BN_CTX_end(ctx); | |
1360 | BN_CTX_free(new_ctx); | |
a4d5269e EK |
1361 | if (new_points) |
1362 | OPENSSL_free(new_points); | |
1363 | if (new_scalars) | |
1364 | OPENSSL_free(new_scalars); | |
4d3fa06f AP |
1365 | return ret; |
1366 | } | |
1367 | ||
5956b110 EK |
1368 | __owur static int ecp_nistz256_get_affine(const EC_GROUP *group, |
1369 | const EC_POINT *point, | |
1370 | BIGNUM *x, BIGNUM *y, BN_CTX *ctx) | |
4d3fa06f AP |
1371 | { |
1372 | BN_ULONG z_inv2[P256_LIMBS]; | |
1373 | BN_ULONG z_inv3[P256_LIMBS]; | |
1374 | BN_ULONG x_aff[P256_LIMBS]; | |
1375 | BN_ULONG y_aff[P256_LIMBS]; | |
1376 | BN_ULONG point_x[P256_LIMBS], point_y[P256_LIMBS], point_z[P256_LIMBS]; | |
e22d2199 | 1377 | BN_ULONG x_ret[P256_LIMBS], y_ret[P256_LIMBS]; |
4d3fa06f AP |
1378 | |
1379 | if (EC_POINT_is_at_infinity(group, point)) { | |
be07ae9b | 1380 | ECerr(EC_F_ECP_NISTZ256_GET_AFFINE, EC_R_POINT_AT_INFINITY); |
4d3fa06f AP |
1381 | return 0; |
1382 | } | |
1383 | ||
5784a521 MC |
1384 | if (!ecp_nistz256_bignum_to_field_elem(point_x, point->X) || |
1385 | !ecp_nistz256_bignum_to_field_elem(point_y, point->Y) || | |
1386 | !ecp_nistz256_bignum_to_field_elem(point_z, point->Z)) { | |
be07ae9b | 1387 | ECerr(EC_F_ECP_NISTZ256_GET_AFFINE, EC_R_COORDINATES_OUT_OF_RANGE); |
4d3fa06f AP |
1388 | return 0; |
1389 | } | |
1390 | ||
1391 | ecp_nistz256_mod_inverse(z_inv3, point_z); | |
1392 | ecp_nistz256_sqr_mont(z_inv2, z_inv3); | |
1393 | ecp_nistz256_mul_mont(x_aff, z_inv2, point_x); | |
1394 | ||
1395 | if (x != NULL) { | |
e22d2199 EK |
1396 | ecp_nistz256_from_mont(x_ret, x_aff); |
1397 | if (!bn_set_words(x, x_ret, P256_LIMBS)) | |
1398 | return 0; | |
4d3fa06f AP |
1399 | } |
1400 | ||
1401 | if (y != NULL) { | |
1402 | ecp_nistz256_mul_mont(z_inv3, z_inv3, z_inv2); | |
1403 | ecp_nistz256_mul_mont(y_aff, z_inv3, point_y); | |
e22d2199 EK |
1404 | ecp_nistz256_from_mont(y_ret, y_aff); |
1405 | if (!bn_set_words(y, y_ret, P256_LIMBS)) | |
1406 | return 0; | |
4d3fa06f AP |
1407 | } |
1408 | ||
1409 | return 1; | |
1410 | } | |
1411 | ||
58d47cf0 | 1412 | static EC_PRE_COMP *ecp_nistz256_pre_comp_new(const EC_GROUP *group) |
4d3fa06f AP |
1413 | { |
1414 | EC_PRE_COMP *ret = NULL; | |
1415 | ||
1416 | if (!group) | |
1417 | return NULL; | |
1418 | ||
b196e7d9 | 1419 | ret = OPENSSL_malloc(sizeof(EC_PRE_COMP)); |
4d3fa06f AP |
1420 | |
1421 | if (!ret) { | |
be07ae9b | 1422 | ECerr(EC_F_ECP_NISTZ256_PRE_COMP_NEW, ERR_R_MALLOC_FAILURE); |
4d3fa06f AP |
1423 | return ret; |
1424 | } | |
1425 | ||
1426 | ret->group = group; | |
1427 | ret->w = 6; /* default */ | |
1428 | ret->precomp = NULL; | |
1429 | ret->precomp_storage = NULL; | |
1430 | ret->references = 1; | |
1431 | return ret; | |
1432 | } | |
1433 | ||
be07ae9b | 1434 | static void *ecp_nistz256_pre_comp_dup(void *src_) |
4d3fa06f AP |
1435 | { |
1436 | EC_PRE_COMP *src = src_; | |
1437 | ||
1438 | /* no need to actually copy, these objects never change! */ | |
1439 | CRYPTO_add(&src->references, 1, CRYPTO_LOCK_EC_PRE_COMP); | |
1440 | ||
1441 | return src_; | |
1442 | } | |
1443 | ||
be07ae9b | 1444 | static void ecp_nistz256_pre_comp_free(void *pre_) |
4d3fa06f AP |
1445 | { |
1446 | int i; | |
1447 | EC_PRE_COMP *pre = pre_; | |
1448 | ||
1449 | if (!pre) | |
1450 | return; | |
1451 | ||
1452 | i = CRYPTO_add(&pre->references, -1, CRYPTO_LOCK_EC_PRE_COMP); | |
1453 | if (i > 0) | |
1454 | return; | |
1455 | ||
1456 | if (pre->precomp_storage) | |
1457 | OPENSSL_free(pre->precomp_storage); | |
1458 | ||
1459 | OPENSSL_free(pre); | |
1460 | } | |
1461 | ||
be07ae9b | 1462 | static void ecp_nistz256_pre_comp_clear_free(void *pre_) |
4d3fa06f AP |
1463 | { |
1464 | int i; | |
1465 | EC_PRE_COMP *pre = pre_; | |
1466 | ||
1467 | if (!pre) | |
1468 | return; | |
1469 | ||
1470 | i = CRYPTO_add(&pre->references, -1, CRYPTO_LOCK_EC_PRE_COMP); | |
1471 | if (i > 0) | |
1472 | return; | |
1473 | ||
1474 | if (pre->precomp_storage) { | |
1475 | OPENSSL_cleanse(pre->precomp, | |
1476 | 32 * sizeof(unsigned char) * (1 << pre->w) * 2 * 37); | |
1477 | OPENSSL_free(pre->precomp_storage); | |
1478 | } | |
1479 | OPENSSL_cleanse(pre, sizeof *pre); | |
1480 | OPENSSL_free(pre); | |
1481 | } | |
1482 | ||
58d47cf0 | 1483 | static int ecp_nistz256_window_have_precompute_mult(const EC_GROUP *group) |
4d3fa06f AP |
1484 | { |
1485 | /* There is a hard-coded table for the default generator. */ | |
1486 | const EC_POINT *generator = EC_GROUP_get0_generator(group); | |
1487 | if (generator != NULL && ecp_nistz256_is_affine_G(generator)) { | |
1488 | /* There is a hard-coded table for the default generator. */ | |
1489 | return 1; | |
1490 | } | |
1491 | ||
be07ae9b AP |
1492 | return EC_EX_DATA_get_data(group->extra_data, ecp_nistz256_pre_comp_dup, |
1493 | ecp_nistz256_pre_comp_free, | |
1494 | ecp_nistz256_pre_comp_clear_free) != NULL; | |
4d3fa06f AP |
1495 | } |
1496 | ||
1497 | const EC_METHOD *EC_GFp_nistz256_method(void) | |
1498 | { | |
1499 | static const EC_METHOD ret = { | |
1500 | EC_FLAGS_DEFAULT_OCT, | |
1501 | NID_X9_62_prime_field, | |
1502 | ec_GFp_mont_group_init, | |
1503 | ec_GFp_mont_group_finish, | |
1504 | ec_GFp_mont_group_clear_finish, | |
1505 | ec_GFp_mont_group_copy, | |
1506 | ec_GFp_mont_group_set_curve, | |
1507 | ec_GFp_simple_group_get_curve, | |
1508 | ec_GFp_simple_group_get_degree, | |
1509 | ec_GFp_simple_group_check_discriminant, | |
1510 | ec_GFp_simple_point_init, | |
1511 | ec_GFp_simple_point_finish, | |
1512 | ec_GFp_simple_point_clear_finish, | |
1513 | ec_GFp_simple_point_copy, | |
1514 | ec_GFp_simple_point_set_to_infinity, | |
1515 | ec_GFp_simple_set_Jprojective_coordinates_GFp, | |
1516 | ec_GFp_simple_get_Jprojective_coordinates_GFp, | |
1517 | ec_GFp_simple_point_set_affine_coordinates, | |
1518 | ecp_nistz256_get_affine, | |
1519 | 0, 0, 0, | |
1520 | ec_GFp_simple_add, | |
1521 | ec_GFp_simple_dbl, | |
1522 | ec_GFp_simple_invert, | |
1523 | ec_GFp_simple_is_at_infinity, | |
1524 | ec_GFp_simple_is_on_curve, | |
1525 | ec_GFp_simple_cmp, | |
1526 | ec_GFp_simple_make_affine, | |
1527 | ec_GFp_simple_points_make_affine, | |
1528 | ecp_nistz256_points_mul, /* mul */ | |
1529 | ecp_nistz256_mult_precompute, /* precompute_mult */ | |
1530 | ecp_nistz256_window_have_precompute_mult, /* have_precompute_mult */ | |
1531 | ec_GFp_mont_field_mul, | |
1532 | ec_GFp_mont_field_sqr, | |
1533 | 0, /* field_div */ | |
1534 | ec_GFp_mont_field_encode, | |
1535 | ec_GFp_mont_field_decode, | |
1536 | ec_GFp_mont_field_set_to_one | |
1537 | }; | |
1538 | ||
1539 | return &ret; | |
1540 | } |