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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 | ||
5784a521 | 31 | #include "internal/bn_int.h" |
4d3fa06f AP |
32 | #include <openssl/err.h> |
33 | #include <openssl/ec.h> | |
34 | #include "cryptlib.h" | |
35 | ||
36 | #include "ec_lcl.h" | |
37 | ||
38 | #if BN_BITS2 != 64 | |
58d47cf0 | 39 | # define TOBN(hi,lo) lo,hi |
4d3fa06f | 40 | #else |
58d47cf0 | 41 | # define TOBN(hi,lo) ((BN_ULONG)hi<<32|lo) |
4d3fa06f AP |
42 | #endif |
43 | ||
44 | #if defined(__GNUC__) | |
58d47cf0 | 45 | # define ALIGN32 __attribute((aligned(32))) |
4d3fa06f | 46 | #elif defined(_MSC_VER) |
58d47cf0 | 47 | # define ALIGN32 __declspec(align(32)) |
4d3fa06f AP |
48 | #else |
49 | # define ALIGN32 | |
50 | #endif | |
51 | ||
58d47cf0 AP |
52 | #define ALIGNPTR(p,N) ((unsigned char *)p+N-(size_t)p%N) |
53 | #define P256_LIMBS (256/BN_BITS2) | |
4d3fa06f AP |
54 | |
55 | typedef unsigned short u16; | |
56 | ||
57 | typedef struct { | |
58 | BN_ULONG X[P256_LIMBS]; | |
59 | BN_ULONG Y[P256_LIMBS]; | |
60 | BN_ULONG Z[P256_LIMBS]; | |
61 | } P256_POINT; | |
62 | ||
63 | typedef struct { | |
64 | BN_ULONG X[P256_LIMBS]; | |
65 | BN_ULONG Y[P256_LIMBS]; | |
66 | } P256_POINT_AFFINE; | |
67 | ||
68 | typedef P256_POINT_AFFINE PRECOMP256_ROW[64]; | |
69 | ||
70 | /* structure for precomputed multiples of the generator */ | |
71 | typedef struct ec_pre_comp_st { | |
72 | const EC_GROUP *group; /* Parent EC_GROUP object */ | |
73 | size_t w; /* Window size */ | |
20728adc AP |
74 | /* |
75 | * Constant time access to the X and Y coordinates of the pre-computed, | |
4d3fa06f | 76 | * generator multiplies, in the Montgomery domain. Pre-calculated |
20728adc AP |
77 | * multiplies are stored in affine form. |
78 | */ | |
4d3fa06f AP |
79 | PRECOMP256_ROW *precomp; |
80 | void *precomp_storage; | |
81 | int references; | |
82 | } EC_PRE_COMP; | |
83 | ||
84 | /* Functions implemented in assembly */ | |
85 | /* Modular mul by 2: res = 2*a mod P */ | |
86 | void ecp_nistz256_mul_by_2(BN_ULONG res[P256_LIMBS], | |
87 | const BN_ULONG a[P256_LIMBS]); | |
88 | /* Modular div by 2: res = a/2 mod P */ | |
89 | void ecp_nistz256_div_by_2(BN_ULONG res[P256_LIMBS], | |
90 | const BN_ULONG a[P256_LIMBS]); | |
91 | /* Modular mul by 3: res = 3*a mod P */ | |
92 | void ecp_nistz256_mul_by_3(BN_ULONG res[P256_LIMBS], | |
93 | const BN_ULONG a[P256_LIMBS]); | |
20728adc | 94 | /* Modular add: res = a+b mod P */ |
4d3fa06f AP |
95 | void ecp_nistz256_add(BN_ULONG res[P256_LIMBS], |
96 | const BN_ULONG a[P256_LIMBS], | |
97 | const BN_ULONG b[P256_LIMBS]); | |
20728adc | 98 | /* Modular sub: res = a-b mod P */ |
4d3fa06f AP |
99 | void ecp_nistz256_sub(BN_ULONG res[P256_LIMBS], |
100 | const BN_ULONG a[P256_LIMBS], | |
101 | const BN_ULONG b[P256_LIMBS]); | |
20728adc | 102 | /* Modular neg: res = -a mod P */ |
4d3fa06f AP |
103 | void ecp_nistz256_neg(BN_ULONG res[P256_LIMBS], const BN_ULONG a[P256_LIMBS]); |
104 | /* Montgomery mul: res = a*b*2^-256 mod P */ | |
105 | void ecp_nistz256_mul_mont(BN_ULONG res[P256_LIMBS], | |
106 | const BN_ULONG a[P256_LIMBS], | |
107 | const BN_ULONG b[P256_LIMBS]); | |
108 | /* Montgomery sqr: res = a*a*2^-256 mod P */ | |
109 | void ecp_nistz256_sqr_mont(BN_ULONG res[P256_LIMBS], | |
110 | const BN_ULONG a[P256_LIMBS]); | |
111 | /* Convert a number from Montgomery domain, by multiplying with 1 */ | |
112 | void ecp_nistz256_from_mont(BN_ULONG res[P256_LIMBS], | |
113 | const BN_ULONG in[P256_LIMBS]); | |
114 | /* Convert a number to Montgomery domain, by multiplying with 2^512 mod P*/ | |
115 | void ecp_nistz256_to_mont(BN_ULONG res[P256_LIMBS], | |
116 | const BN_ULONG in[P256_LIMBS]); | |
117 | /* Functions that perform constant time access to the precomputed tables */ | |
58d47cf0 | 118 | void ecp_nistz256_scatter_w5(P256_POINT *val, |
49b05c7d | 119 | const P256_POINT *in_t, int idx); |
20728adc | 120 | void ecp_nistz256_gather_w5(P256_POINT *val, |
49b05c7d | 121 | const P256_POINT *in_t, int idx); |
58d47cf0 | 122 | void ecp_nistz256_scatter_w7(P256_POINT_AFFINE *val, |
49b05c7d | 123 | const P256_POINT_AFFINE *in_t, int idx); |
58d47cf0 | 124 | void ecp_nistz256_gather_w7(P256_POINT_AFFINE *val, |
49b05c7d | 125 | const P256_POINT_AFFINE *in_t, int idx); |
4d3fa06f AP |
126 | |
127 | /* One converted into the Montgomery domain */ | |
128 | static const BN_ULONG ONE[P256_LIMBS] = { | |
129 | TOBN(0x00000000, 0x00000001), TOBN(0xffffffff, 0x00000000), | |
130 | TOBN(0xffffffff, 0xffffffff), TOBN(0x00000000, 0xfffffffe) | |
131 | }; | |
132 | ||
be07ae9b AP |
133 | static void *ecp_nistz256_pre_comp_dup(void *); |
134 | static void ecp_nistz256_pre_comp_free(void *); | |
135 | static void ecp_nistz256_pre_comp_clear_free(void *); | |
58d47cf0 | 136 | static EC_PRE_COMP *ecp_nistz256_pre_comp_new(const EC_GROUP *group); |
4d3fa06f AP |
137 | |
138 | /* Precomputed tables for the default generator */ | |
3ff08e1d | 139 | extern const PRECOMP256_ROW ecp_nistz256_precomputed[37]; |
4d3fa06f AP |
140 | |
141 | /* Recode window to a signed digit, see ecp_nistputil.c for details */ | |
142 | static unsigned int _booth_recode_w5(unsigned int in) | |
143 | { | |
144 | unsigned int s, d; | |
145 | ||
146 | s = ~((in >> 5) - 1); | |
147 | d = (1 << 6) - in - 1; | |
148 | d = (d & s) | (in & ~s); | |
149 | d = (d >> 1) + (d & 1); | |
150 | ||
151 | return (d << 1) + (s & 1); | |
152 | } | |
153 | ||
154 | static unsigned int _booth_recode_w7(unsigned int in) | |
155 | { | |
156 | unsigned int s, d; | |
157 | ||
158 | s = ~((in >> 7) - 1); | |
159 | d = (1 << 8) - in - 1; | |
160 | d = (d & s) | (in & ~s); | |
161 | d = (d >> 1) + (d & 1); | |
162 | ||
163 | return (d << 1) + (s & 1); | |
164 | } | |
165 | ||
166 | static void copy_conditional(BN_ULONG dst[P256_LIMBS], | |
167 | const BN_ULONG src[P256_LIMBS], BN_ULONG move) | |
168 | { | |
169 | BN_ULONG mask1 = -move; | |
170 | BN_ULONG mask2 = ~mask1; | |
171 | ||
172 | dst[0] = (src[0] & mask1) ^ (dst[0] & mask2); | |
173 | dst[1] = (src[1] & mask1) ^ (dst[1] & mask2); | |
174 | dst[2] = (src[2] & mask1) ^ (dst[2] & mask2); | |
175 | dst[3] = (src[3] & mask1) ^ (dst[3] & mask2); | |
176 | if (P256_LIMBS == 8) { | |
177 | dst[4] = (src[4] & mask1) ^ (dst[4] & mask2); | |
178 | dst[5] = (src[5] & mask1) ^ (dst[5] & mask2); | |
179 | dst[6] = (src[6] & mask1) ^ (dst[6] & mask2); | |
180 | dst[7] = (src[7] & mask1) ^ (dst[7] & mask2); | |
181 | } | |
182 | } | |
183 | ||
184 | static BN_ULONG is_zero(BN_ULONG in) | |
185 | { | |
186 | in |= (0 - in); | |
187 | in = ~in; | |
188 | in &= BN_MASK2; | |
189 | in >>= BN_BITS2 - 1; | |
190 | return in; | |
191 | } | |
192 | ||
193 | static BN_ULONG is_equal(const BN_ULONG a[P256_LIMBS], | |
194 | const BN_ULONG b[P256_LIMBS]) | |
195 | { | |
196 | BN_ULONG res; | |
197 | ||
198 | res = a[0] ^ b[0]; | |
199 | res |= a[1] ^ b[1]; | |
200 | res |= a[2] ^ b[2]; | |
201 | res |= a[3] ^ b[3]; | |
202 | if (P256_LIMBS == 8) { | |
203 | res |= a[4] ^ b[4]; | |
204 | res |= a[5] ^ b[5]; | |
205 | res |= a[6] ^ b[6]; | |
206 | res |= a[7] ^ b[7]; | |
207 | } | |
208 | ||
209 | return is_zero(res); | |
210 | } | |
211 | ||
212 | static BN_ULONG is_one(const BN_ULONG a[P256_LIMBS]) | |
213 | { | |
214 | BN_ULONG res; | |
215 | ||
216 | res = a[0] ^ ONE[0]; | |
217 | res |= a[1] ^ ONE[1]; | |
218 | res |= a[2] ^ ONE[2]; | |
219 | res |= a[3] ^ ONE[3]; | |
220 | if (P256_LIMBS == 8) { | |
221 | res |= a[4] ^ ONE[4]; | |
222 | res |= a[5] ^ ONE[5]; | |
223 | res |= a[6] ^ ONE[6]; | |
224 | } | |
225 | ||
226 | return is_zero(res); | |
227 | } | |
228 | ||
229 | #ifndef ECP_NISTZ256_REFERENCE_IMPLEMENTATION | |
58d47cf0 AP |
230 | void ecp_nistz256_point_double(P256_POINT *r, const P256_POINT *a); |
231 | void ecp_nistz256_point_add(P256_POINT *r, | |
232 | const P256_POINT *a, const P256_POINT *b); | |
233 | void ecp_nistz256_point_add_affine(P256_POINT *r, | |
234 | const P256_POINT *a, | |
235 | const P256_POINT_AFFINE *b); | |
4d3fa06f AP |
236 | #else |
237 | /* Point double: r = 2*a */ | |
58d47cf0 | 238 | static void ecp_nistz256_point_double(P256_POINT *r, const P256_POINT *a) |
4d3fa06f AP |
239 | { |
240 | BN_ULONG S[P256_LIMBS]; | |
241 | BN_ULONG M[P256_LIMBS]; | |
242 | BN_ULONG Zsqr[P256_LIMBS]; | |
243 | BN_ULONG tmp0[P256_LIMBS]; | |
244 | ||
245 | const BN_ULONG *in_x = a->X; | |
246 | const BN_ULONG *in_y = a->Y; | |
247 | const BN_ULONG *in_z = a->Z; | |
248 | ||
249 | BN_ULONG *res_x = r->X; | |
250 | BN_ULONG *res_y = r->Y; | |
251 | BN_ULONG *res_z = r->Z; | |
252 | ||
253 | ecp_nistz256_mul_by_2(S, in_y); | |
254 | ||
255 | ecp_nistz256_sqr_mont(Zsqr, in_z); | |
256 | ||
257 | ecp_nistz256_sqr_mont(S, S); | |
258 | ||
259 | ecp_nistz256_mul_mont(res_z, in_z, in_y); | |
260 | ecp_nistz256_mul_by_2(res_z, res_z); | |
261 | ||
262 | ecp_nistz256_add(M, in_x, Zsqr); | |
263 | ecp_nistz256_sub(Zsqr, in_x, Zsqr); | |
264 | ||
265 | ecp_nistz256_sqr_mont(res_y, S); | |
266 | ecp_nistz256_div_by_2(res_y, res_y); | |
267 | ||
268 | ecp_nistz256_mul_mont(M, M, Zsqr); | |
269 | ecp_nistz256_mul_by_3(M, M); | |
270 | ||
271 | ecp_nistz256_mul_mont(S, S, in_x); | |
272 | ecp_nistz256_mul_by_2(tmp0, S); | |
273 | ||
274 | ecp_nistz256_sqr_mont(res_x, M); | |
275 | ||
276 | ecp_nistz256_sub(res_x, res_x, tmp0); | |
277 | ecp_nistz256_sub(S, S, res_x); | |
278 | ||
279 | ecp_nistz256_mul_mont(S, S, M); | |
280 | ecp_nistz256_sub(res_y, S, res_y); | |
281 | } | |
282 | ||
283 | /* Point addition: r = a+b */ | |
20728adc AP |
284 | static void ecp_nistz256_point_add(P256_POINT *r, |
285 | const P256_POINT *a, const P256_POINT *b) | |
4d3fa06f AP |
286 | { |
287 | BN_ULONG U2[P256_LIMBS], S2[P256_LIMBS]; | |
288 | BN_ULONG U1[P256_LIMBS], S1[P256_LIMBS]; | |
289 | BN_ULONG Z1sqr[P256_LIMBS]; | |
290 | BN_ULONG Z2sqr[P256_LIMBS]; | |
291 | BN_ULONG H[P256_LIMBS], R[P256_LIMBS]; | |
292 | BN_ULONG Hsqr[P256_LIMBS]; | |
293 | BN_ULONG Rsqr[P256_LIMBS]; | |
294 | BN_ULONG Hcub[P256_LIMBS]; | |
295 | ||
296 | BN_ULONG res_x[P256_LIMBS]; | |
297 | BN_ULONG res_y[P256_LIMBS]; | |
298 | BN_ULONG res_z[P256_LIMBS]; | |
299 | ||
300 | BN_ULONG in1infty, in2infty; | |
301 | ||
302 | const BN_ULONG *in1_x = a->X; | |
303 | const BN_ULONG *in1_y = a->Y; | |
304 | const BN_ULONG *in1_z = a->Z; | |
305 | ||
306 | const BN_ULONG *in2_x = b->X; | |
307 | const BN_ULONG *in2_y = b->Y; | |
308 | const BN_ULONG *in2_z = b->Z; | |
309 | ||
310 | /* We encode infinity as (0,0), which is not on the curve, | |
311 | * so it is OK. */ | |
58d47cf0 AP |
312 | in1infty = (in1_x[0] | in1_x[1] | in1_x[2] | in1_x[3] | |
313 | in1_y[0] | in1_y[1] | in1_y[2] | in1_y[3]); | |
4d3fa06f | 314 | if (P256_LIMBS == 8) |
58d47cf0 AP |
315 | in1infty |= (in1_x[4] | in1_x[5] | in1_x[6] | in1_x[7] | |
316 | in1_y[4] | in1_y[5] | in1_y[6] | in1_y[7]); | |
4d3fa06f | 317 | |
58d47cf0 AP |
318 | in2infty = (in2_x[0] | in2_x[1] | in2_x[2] | in2_x[3] | |
319 | in2_y[0] | in2_y[1] | in2_y[2] | in2_y[3]); | |
4d3fa06f | 320 | if (P256_LIMBS == 8) |
58d47cf0 AP |
321 | in2infty |= (in2_x[4] | in2_x[5] | in2_x[6] | in2_x[7] | |
322 | in2_y[4] | in2_y[5] | in2_y[6] | in2_y[7]); | |
4d3fa06f AP |
323 | |
324 | in1infty = is_zero(in1infty); | |
325 | in2infty = is_zero(in2infty); | |
326 | ||
327 | ecp_nistz256_sqr_mont(Z2sqr, in2_z); /* Z2^2 */ | |
328 | ecp_nistz256_sqr_mont(Z1sqr, in1_z); /* Z1^2 */ | |
329 | ||
330 | ecp_nistz256_mul_mont(S1, Z2sqr, in2_z); /* S1 = Z2^3 */ | |
331 | ecp_nistz256_mul_mont(S2, Z1sqr, in1_z); /* S2 = Z1^3 */ | |
332 | ||
333 | ecp_nistz256_mul_mont(S1, S1, in1_y); /* S1 = Y1*Z2^3 */ | |
334 | ecp_nistz256_mul_mont(S2, S2, in2_y); /* S2 = Y2*Z1^3 */ | |
335 | ecp_nistz256_sub(R, S2, S1); /* R = S2 - S1 */ | |
336 | ||
337 | ecp_nistz256_mul_mont(U1, in1_x, Z2sqr); /* U1 = X1*Z2^2 */ | |
338 | ecp_nistz256_mul_mont(U2, in2_x, Z1sqr); /* U2 = X2*Z1^2 */ | |
339 | ecp_nistz256_sub(H, U2, U1); /* H = U2 - U1 */ | |
340 | ||
20728adc AP |
341 | /* |
342 | * This should not happen during sign/ecdh, so no constant time violation | |
343 | */ | |
4d3fa06f AP |
344 | if (is_equal(U1, U2) && !in1infty && !in2infty) { |
345 | if (is_equal(S1, S2)) { | |
346 | ecp_nistz256_point_double(r, a); | |
347 | return; | |
348 | } else { | |
349 | memset(r, 0, sizeof(*r)); | |
350 | return; | |
351 | } | |
352 | } | |
353 | ||
354 | ecp_nistz256_sqr_mont(Rsqr, R); /* R^2 */ | |
355 | ecp_nistz256_mul_mont(res_z, H, in1_z); /* Z3 = H*Z1*Z2 */ | |
356 | ecp_nistz256_sqr_mont(Hsqr, H); /* H^2 */ | |
357 | ecp_nistz256_mul_mont(res_z, res_z, in2_z); /* Z3 = H*Z1*Z2 */ | |
358 | ecp_nistz256_mul_mont(Hcub, Hsqr, H); /* H^3 */ | |
359 | ||
360 | ecp_nistz256_mul_mont(U2, U1, Hsqr); /* U1*H^2 */ | |
361 | ecp_nistz256_mul_by_2(Hsqr, U2); /* 2*U1*H^2 */ | |
362 | ||
363 | ecp_nistz256_sub(res_x, Rsqr, Hsqr); | |
364 | ecp_nistz256_sub(res_x, res_x, Hcub); | |
365 | ||
366 | ecp_nistz256_sub(res_y, U2, res_x); | |
367 | ||
368 | ecp_nistz256_mul_mont(S2, S1, Hcub); | |
369 | ecp_nistz256_mul_mont(res_y, R, res_y); | |
370 | ecp_nistz256_sub(res_y, res_y, S2); | |
371 | ||
372 | copy_conditional(res_x, in2_x, in1infty); | |
373 | copy_conditional(res_y, in2_y, in1infty); | |
374 | copy_conditional(res_z, in2_z, in1infty); | |
375 | ||
376 | copy_conditional(res_x, in1_x, in2infty); | |
377 | copy_conditional(res_y, in1_y, in2infty); | |
378 | copy_conditional(res_z, in1_z, in2infty); | |
379 | ||
380 | memcpy(r->X, res_x, sizeof(res_x)); | |
381 | memcpy(r->Y, res_y, sizeof(res_y)); | |
382 | memcpy(r->Z, res_z, sizeof(res_z)); | |
383 | } | |
384 | ||
385 | /* Point addition when b is known to be affine: r = a+b */ | |
58d47cf0 AP |
386 | static void ecp_nistz256_point_add_affine(P256_POINT *r, |
387 | const P256_POINT *a, | |
388 | const P256_POINT_AFFINE *b) | |
4d3fa06f AP |
389 | { |
390 | BN_ULONG U2[P256_LIMBS], S2[P256_LIMBS]; | |
391 | BN_ULONG Z1sqr[P256_LIMBS]; | |
392 | BN_ULONG H[P256_LIMBS], R[P256_LIMBS]; | |
393 | BN_ULONG Hsqr[P256_LIMBS]; | |
394 | BN_ULONG Rsqr[P256_LIMBS]; | |
395 | BN_ULONG Hcub[P256_LIMBS]; | |
396 | ||
397 | BN_ULONG res_x[P256_LIMBS]; | |
398 | BN_ULONG res_y[P256_LIMBS]; | |
399 | BN_ULONG res_z[P256_LIMBS]; | |
400 | ||
401 | BN_ULONG in1infty, in2infty; | |
402 | ||
403 | const BN_ULONG *in1_x = a->X; | |
404 | const BN_ULONG *in1_y = a->Y; | |
405 | const BN_ULONG *in1_z = a->Z; | |
406 | ||
407 | const BN_ULONG *in2_x = b->X; | |
408 | const BN_ULONG *in2_y = b->Y; | |
409 | ||
20728adc AP |
410 | /* |
411 | * In affine representation we encode infty as (0,0), which is not on the | |
412 | * curve, so it is OK | |
413 | */ | |
58d47cf0 AP |
414 | in1infty = (in1_x[0] | in1_x[1] | in1_x[2] | in1_x[3] | |
415 | in1_y[0] | in1_y[1] | in1_y[2] | in1_y[3]); | |
4d3fa06f | 416 | if (P256_LIMBS == 8) |
58d47cf0 AP |
417 | in1infty |= (in1_x[4] | in1_x[5] | in1_x[6] | in1_x[7] | |
418 | in1_y[4] | in1_y[5] | in1_y[6] | in1_y[7]); | |
4d3fa06f | 419 | |
58d47cf0 AP |
420 | in2infty = (in2_x[0] | in2_x[1] | in2_x[2] | in2_x[3] | |
421 | in2_y[0] | in2_y[1] | in2_y[2] | in2_y[3]); | |
4d3fa06f | 422 | if (P256_LIMBS == 8) |
58d47cf0 AP |
423 | in2infty |= (in2_x[4] | in2_x[5] | in2_x[6] | in2_x[7] | |
424 | in2_y[4] | in2_y[5] | in2_y[6] | in2_y[7]); | |
4d3fa06f AP |
425 | |
426 | in1infty = is_zero(in1infty); | |
427 | in2infty = is_zero(in2infty); | |
428 | ||
429 | ecp_nistz256_sqr_mont(Z1sqr, in1_z); /* Z1^2 */ | |
430 | ||
431 | ecp_nistz256_mul_mont(U2, in2_x, Z1sqr); /* U2 = X2*Z1^2 */ | |
432 | ecp_nistz256_sub(H, U2, in1_x); /* H = U2 - U1 */ | |
433 | ||
434 | ecp_nistz256_mul_mont(S2, Z1sqr, in1_z); /* S2 = Z1^3 */ | |
435 | ||
436 | ecp_nistz256_mul_mont(res_z, H, in1_z); /* Z3 = H*Z1*Z2 */ | |
437 | ||
438 | ecp_nistz256_mul_mont(S2, S2, in2_y); /* S2 = Y2*Z1^3 */ | |
439 | ecp_nistz256_sub(R, S2, in1_y); /* R = S2 - S1 */ | |
440 | ||
441 | ecp_nistz256_sqr_mont(Hsqr, H); /* H^2 */ | |
442 | ecp_nistz256_sqr_mont(Rsqr, R); /* R^2 */ | |
443 | ecp_nistz256_mul_mont(Hcub, Hsqr, H); /* H^3 */ | |
444 | ||
445 | ecp_nistz256_mul_mont(U2, in1_x, Hsqr); /* U1*H^2 */ | |
446 | ecp_nistz256_mul_by_2(Hsqr, U2); /* 2*U1*H^2 */ | |
447 | ||
448 | ecp_nistz256_sub(res_x, Rsqr, Hsqr); | |
449 | ecp_nistz256_sub(res_x, res_x, Hcub); | |
450 | ecp_nistz256_sub(H, U2, res_x); | |
451 | ||
452 | ecp_nistz256_mul_mont(S2, in1_y, Hcub); | |
453 | ecp_nistz256_mul_mont(H, H, R); | |
454 | ecp_nistz256_sub(res_y, H, S2); | |
455 | ||
456 | copy_conditional(res_x, in2_x, in1infty); | |
457 | copy_conditional(res_x, in1_x, in2infty); | |
458 | ||
459 | copy_conditional(res_y, in2_y, in1infty); | |
460 | copy_conditional(res_y, in1_y, in2infty); | |
461 | ||
462 | copy_conditional(res_z, ONE, in1infty); | |
463 | copy_conditional(res_z, in1_z, in2infty); | |
464 | ||
465 | memcpy(r->X, res_x, sizeof(res_x)); | |
466 | memcpy(r->Y, res_y, sizeof(res_y)); | |
467 | memcpy(r->Z, res_z, sizeof(res_z)); | |
468 | } | |
469 | #endif | |
470 | ||
471 | /* r = in^-1 mod p */ | |
472 | static void ecp_nistz256_mod_inverse(BN_ULONG r[P256_LIMBS], | |
473 | const BN_ULONG in[P256_LIMBS]) | |
474 | { | |
20728adc AP |
475 | /* |
476 | * The poly is ffffffff 00000001 00000000 00000000 00000000 ffffffff | |
477 | * ffffffff ffffffff We use FLT and used poly-2 as exponent | |
478 | */ | |
4d3fa06f AP |
479 | BN_ULONG p2[P256_LIMBS]; |
480 | BN_ULONG p4[P256_LIMBS]; | |
481 | BN_ULONG p8[P256_LIMBS]; | |
482 | BN_ULONG p16[P256_LIMBS]; | |
483 | BN_ULONG p32[P256_LIMBS]; | |
484 | BN_ULONG res[P256_LIMBS]; | |
485 | int i; | |
486 | ||
487 | ecp_nistz256_sqr_mont(res, in); | |
488 | ecp_nistz256_mul_mont(p2, res, in); /* 3*p */ | |
489 | ||
490 | ecp_nistz256_sqr_mont(res, p2); | |
491 | ecp_nistz256_sqr_mont(res, res); | |
492 | ecp_nistz256_mul_mont(p4, res, p2); /* f*p */ | |
493 | ||
494 | ecp_nistz256_sqr_mont(res, p4); | |
495 | ecp_nistz256_sqr_mont(res, res); | |
496 | ecp_nistz256_sqr_mont(res, res); | |
497 | ecp_nistz256_sqr_mont(res, res); | |
498 | ecp_nistz256_mul_mont(p8, res, p4); /* ff*p */ | |
499 | ||
500 | ecp_nistz256_sqr_mont(res, p8); | |
501 | for (i = 0; i < 7; i++) | |
502 | ecp_nistz256_sqr_mont(res, res); | |
503 | ecp_nistz256_mul_mont(p16, res, p8); /* ffff*p */ | |
504 | ||
505 | ecp_nistz256_sqr_mont(res, p16); | |
506 | for (i = 0; i < 15; i++) | |
507 | ecp_nistz256_sqr_mont(res, res); | |
508 | ecp_nistz256_mul_mont(p32, res, p16); /* ffffffff*p */ | |
509 | ||
510 | ecp_nistz256_sqr_mont(res, p32); | |
511 | for (i = 0; i < 31; i++) | |
512 | ecp_nistz256_sqr_mont(res, res); | |
513 | ecp_nistz256_mul_mont(res, res, in); | |
514 | ||
515 | for (i = 0; i < 32 * 4; i++) | |
516 | ecp_nistz256_sqr_mont(res, res); | |
517 | ecp_nistz256_mul_mont(res, res, p32); | |
518 | ||
519 | for (i = 0; i < 32; i++) | |
520 | ecp_nistz256_sqr_mont(res, res); | |
521 | ecp_nistz256_mul_mont(res, res, p32); | |
522 | ||
523 | for (i = 0; i < 16; i++) | |
524 | ecp_nistz256_sqr_mont(res, res); | |
525 | ecp_nistz256_mul_mont(res, res, p16); | |
526 | ||
527 | for (i = 0; i < 8; i++) | |
528 | ecp_nistz256_sqr_mont(res, res); | |
529 | ecp_nistz256_mul_mont(res, res, p8); | |
530 | ||
531 | ecp_nistz256_sqr_mont(res, res); | |
532 | ecp_nistz256_sqr_mont(res, res); | |
533 | ecp_nistz256_sqr_mont(res, res); | |
534 | ecp_nistz256_sqr_mont(res, res); | |
535 | ecp_nistz256_mul_mont(res, res, p4); | |
536 | ||
537 | ecp_nistz256_sqr_mont(res, res); | |
538 | ecp_nistz256_sqr_mont(res, res); | |
539 | ecp_nistz256_mul_mont(res, res, p2); | |
540 | ||
541 | ecp_nistz256_sqr_mont(res, res); | |
542 | ecp_nistz256_sqr_mont(res, res); | |
543 | ecp_nistz256_mul_mont(res, res, in); | |
544 | ||
545 | memcpy(r, res, sizeof(res)); | |
546 | } | |
547 | ||
20728adc AP |
548 | /* |
549 | * ecp_nistz256_bignum_to_field_elem copies the contents of |in| to |out| and | |
550 | * returns one if it fits. Otherwise it returns zero. | |
551 | */ | |
4d3fa06f | 552 | static int ecp_nistz256_bignum_to_field_elem(BN_ULONG out[P256_LIMBS], |
20728adc | 553 | const BIGNUM *in) |
4d3fa06f | 554 | { |
5784a521 | 555 | return bn_copy_words(out, in, P256_LIMBS); |
4d3fa06f AP |
556 | } |
557 | ||
558 | /* r = sum(scalar[i]*point[i]) */ | |
58d47cf0 AP |
559 | static void ecp_nistz256_windowed_mul(const EC_GROUP *group, |
560 | P256_POINT *r, | |
561 | const BIGNUM **scalar, | |
562 | const EC_POINT **point, | |
563 | int num, BN_CTX *ctx) | |
4d3fa06f AP |
564 | { |
565 | int i, j; | |
49b05c7d | 566 | unsigned int idx; |
4d3fa06f AP |
567 | unsigned char (*p_str)[33] = NULL; |
568 | const unsigned int window_size = 5; | |
569 | const unsigned int mask = (1 << (window_size + 1)) - 1; | |
570 | unsigned int wvalue; | |
20728adc | 571 | P256_POINT *temp; /* place for 5 temporary points */ |
4d3fa06f | 572 | const BIGNUM **scalars = NULL; |
20728adc | 573 | P256_POINT (*table)[16] = NULL; |
4d3fa06f AP |
574 | void *table_storage = NULL; |
575 | ||
576 | if ((table_storage = | |
3ff08e1d | 577 | OPENSSL_malloc((num * 16 + 5) * sizeof(P256_POINT) + 64)) == NULL |
4d3fa06f AP |
578 | || (p_str = |
579 | OPENSSL_malloc(num * 33 * sizeof(unsigned char))) == NULL | |
580 | || (scalars = OPENSSL_malloc(num * sizeof(BIGNUM *))) == NULL) { | |
be07ae9b | 581 | ECerr(EC_F_ECP_NISTZ256_WINDOWED_MUL, ERR_R_MALLOC_FAILURE); |
4d3fa06f | 582 | goto err; |
4d3fa06f AP |
583 | } |
584 | ||
3ff08e1d | 585 | table = (void *)ALIGNPTR(table_storage, 64); |
20728adc | 586 | temp = (P256_POINT *)(table + num); |
3ff08e1d | 587 | |
4d3fa06f AP |
588 | for (i = 0; i < num; i++) { |
589 | P256_POINT *row = table[i]; | |
590 | ||
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 AP |
606 | |
607 | p_str[i][j + 0] = d & 0xff; | |
608 | p_str[i][j + 1] = (d >> 8) & 0xff; | |
609 | p_str[i][j + 2] = (d >> 16) & 0xff; | |
610 | p_str[i][j + 3] = (d >>= 24) & 0xff; | |
611 | if (BN_BYTES == 8) { | |
612 | d >>= 8; | |
613 | p_str[i][j + 4] = d & 0xff; | |
614 | p_str[i][j + 5] = (d >> 8) & 0xff; | |
615 | p_str[i][j + 6] = (d >> 16) & 0xff; | |
616 | p_str[i][j + 7] = (d >> 24) & 0xff; | |
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 | ||
58d47cf0 | 722 | err: |
4d3fa06f AP |
723 | if (table_storage) |
724 | OPENSSL_free(table_storage); | |
725 | if (p_str) | |
726 | OPENSSL_free(p_str); | |
727 | if (scalars) | |
728 | OPENSSL_free(scalars); | |
729 | } | |
730 | ||
731 | /* Coordinates of G, for which we have precomputed tables */ | |
732 | const static BN_ULONG def_xG[P256_LIMBS] = { | |
733 | TOBN(0x79e730d4, 0x18a9143c), TOBN(0x75ba95fc, 0x5fedb601), | |
734 | TOBN(0x79fb732b, 0x77622510), TOBN(0x18905f76, 0xa53755c6) | |
735 | }; | |
736 | ||
737 | const static BN_ULONG def_yG[P256_LIMBS] = { | |
738 | TOBN(0xddf25357, 0xce95560a), TOBN(0x8b4ab8e4, 0xba19e45c), | |
739 | TOBN(0xd2e88688, 0xdd21f325), TOBN(0x8571ff18, 0x25885d85) | |
740 | }; | |
741 | ||
20728adc AP |
742 | /* |
743 | * ecp_nistz256_is_affine_G returns one if |generator| is the standard, P-256 | |
744 | * generator. | |
745 | */ | |
58d47cf0 | 746 | static int ecp_nistz256_is_affine_G(const EC_POINT *generator) |
4d3fa06f | 747 | { |
5784a521 MC |
748 | return (bn_get_top(generator->X) == P256_LIMBS) && |
749 | (bn_get_top(generator->Y) == P256_LIMBS) && | |
750 | (bn_get_top(generator->Z) == (P256_LIMBS - P256_LIMBS / 8)) && | |
751 | is_equal(bn_get_words(generator->X), def_xG) && | |
752 | is_equal(bn_get_words(generator->Y), def_yG) && | |
753 | is_one(bn_get_words(generator->Z)); | |
4d3fa06f AP |
754 | } |
755 | ||
58d47cf0 | 756 | static int ecp_nistz256_mult_precompute(EC_GROUP *group, BN_CTX *ctx) |
4d3fa06f | 757 | { |
20728adc AP |
758 | /* |
759 | * We precompute a table for a Booth encoded exponent (wNAF) based | |
4d3fa06f | 760 | * computation. Each table holds 64 values for safe access, with an |
20728adc AP |
761 | * implicit value of infinity at index zero. We use window of size 7, and |
762 | * therefore require ceil(256/7) = 37 tables. | |
763 | */ | |
4d3fa06f AP |
764 | BIGNUM *order; |
765 | EC_POINT *P = NULL, *T = NULL; | |
766 | const EC_POINT *generator; | |
767 | EC_PRE_COMP *pre_comp; | |
768 | int i, j, k, ret = 0; | |
769 | size_t w; | |
770 | ||
771 | PRECOMP256_ROW *preComputedTable = NULL; | |
772 | unsigned char *precomp_storage = NULL; | |
773 | ||
774 | /* if there is an old EC_PRE_COMP object, throw it away */ | |
be07ae9b AP |
775 | EC_EX_DATA_free_data(&group->extra_data, ecp_nistz256_pre_comp_dup, |
776 | ecp_nistz256_pre_comp_free, | |
777 | ecp_nistz256_pre_comp_clear_free); | |
4d3fa06f AP |
778 | |
779 | generator = EC_GROUP_get0_generator(group); | |
780 | if (generator == NULL) { | |
be07ae9b | 781 | ECerr(EC_F_ECP_NISTZ256_MULT_PRECOMPUTE, EC_R_UNDEFINED_GENERATOR); |
4d3fa06f AP |
782 | return 0; |
783 | } | |
784 | ||
785 | if (ecp_nistz256_is_affine_G(generator)) { | |
20728adc AP |
786 | /* |
787 | * No need to calculate tables for the standard generator because we | |
788 | * have them statically. | |
789 | */ | |
4d3fa06f AP |
790 | return 1; |
791 | } | |
792 | ||
be07ae9b | 793 | if ((pre_comp = ecp_nistz256_pre_comp_new(group)) == NULL) |
4d3fa06f AP |
794 | return 0; |
795 | ||
796 | if (ctx == NULL) { | |
797 | ctx = BN_CTX_new(); | |
798 | if (ctx == NULL) | |
799 | goto err; | |
800 | } | |
801 | ||
802 | BN_CTX_start(ctx); | |
803 | order = BN_CTX_get(ctx); | |
804 | ||
805 | if (order == NULL) | |
806 | goto err; | |
807 | ||
808 | if (!EC_GROUP_get_order(group, order, ctx)) | |
809 | goto err; | |
810 | ||
811 | if (BN_is_zero(order)) { | |
be07ae9b | 812 | ECerr(EC_F_ECP_NISTZ256_MULT_PRECOMPUTE, EC_R_UNKNOWN_ORDER); |
4d3fa06f AP |
813 | goto err; |
814 | } | |
815 | ||
816 | w = 7; | |
817 | ||
818 | if ((precomp_storage = | |
819 | OPENSSL_malloc(37 * 64 * sizeof(P256_POINT_AFFINE) + 64)) == NULL) { | |
be07ae9b | 820 | ECerr(EC_F_ECP_NISTZ256_MULT_PRECOMPUTE, ERR_R_MALLOC_FAILURE); |
4d3fa06f | 821 | goto err; |
4d3fa06f AP |
822 | } |
823 | ||
3ff08e1d AP |
824 | preComputedTable = (void *)ALIGNPTR(precomp_storage, 64); |
825 | ||
4d3fa06f AP |
826 | P = EC_POINT_new(group); |
827 | T = EC_POINT_new(group); | |
828 | ||
20728adc AP |
829 | /* |
830 | * The zero entry is implicitly infinity, and we skip it, storing other | |
831 | * values with -1 offset. | |
832 | */ | |
4d3fa06f AP |
833 | EC_POINT_copy(T, generator); |
834 | ||
835 | for (k = 0; k < 64; k++) { | |
836 | EC_POINT_copy(P, T); | |
837 | for (j = 0; j < 37; j++) { | |
3ff08e1d | 838 | P256_POINT_AFFINE temp; |
20728adc AP |
839 | /* |
840 | * It would be faster to use ec_GFp_simple_points_make_affine and | |
841 | * make multiple points affine at the same time. | |
842 | */ | |
4d3fa06f | 843 | ec_GFp_simple_make_affine(group, P, ctx); |
5784a521 MC |
844 | ecp_nistz256_bignum_to_field_elem(temp.X, P->X); |
845 | ecp_nistz256_bignum_to_field_elem(temp.Y, P->Y); | |
3ff08e1d | 846 | ecp_nistz256_scatter_w7(preComputedTable[j], &temp, k); |
4d3fa06f AP |
847 | for (i = 0; i < 7; i++) |
848 | ec_GFp_simple_dbl(group, P, P, ctx); | |
849 | } | |
850 | ec_GFp_simple_add(group, T, T, generator, ctx); | |
851 | } | |
852 | ||
853 | pre_comp->group = group; | |
854 | pre_comp->w = w; | |
855 | pre_comp->precomp = preComputedTable; | |
856 | pre_comp->precomp_storage = precomp_storage; | |
857 | ||
858 | precomp_storage = NULL; | |
859 | ||
860 | if (!EC_EX_DATA_set_data(&group->extra_data, pre_comp, | |
be07ae9b AP |
861 | ecp_nistz256_pre_comp_dup, |
862 | ecp_nistz256_pre_comp_free, | |
863 | ecp_nistz256_pre_comp_clear_free)) { | |
4d3fa06f AP |
864 | goto err; |
865 | } | |
866 | ||
867 | pre_comp = NULL; | |
868 | ||
869 | ret = 1; | |
870 | ||
58d47cf0 | 871 | err: |
4d3fa06f AP |
872 | if (ctx != NULL) |
873 | BN_CTX_end(ctx); | |
874 | if (pre_comp) | |
be07ae9b | 875 | ecp_nistz256_pre_comp_free(pre_comp); |
4d3fa06f AP |
876 | if (precomp_storage) |
877 | OPENSSL_free(precomp_storage); | |
878 | if (P) | |
879 | EC_POINT_free(P); | |
880 | if (T) | |
881 | EC_POINT_free(T); | |
882 | return ret; | |
883 | } | |
884 | ||
885 | /* | |
886 | * Note that by default ECP_NISTZ256_AVX2 is undefined. While it's great | |
887 | * code processing 4 points in parallel, corresponding serial operation | |
888 | * is several times slower, because it uses 29x29=58-bit multiplication | |
889 | * as opposite to 64x64=128-bit in integer-only scalar case. As result | |
890 | * it doesn't provide *significant* performance improvement. Note that | |
891 | * just defining ECP_NISTZ256_AVX2 is not sufficient to make it work, | |
892 | * you'd need to compile even asm/ecp_nistz256-avx.pl module. | |
893 | */ | |
894 | #if defined(ECP_NISTZ256_AVX2) | |
3ff08e1d | 895 | # if !(defined(__x86_64) || defined(__x86_64__) || \ |
4d3fa06f AP |
896 | defined(_M_AMD64) || defined(_MX64)) || \ |
897 | !(defined(__GNUC__) || defined(_MSC_VER)) /* this is for ALIGN32 */ | |
898 | # undef ECP_NISTZ256_AVX2 | |
899 | # else | |
900 | /* Constant time access, loading four values, from four consecutive tables */ | |
58d47cf0 AP |
901 | void ecp_nistz256_avx2_multi_gather_w7(void *result, const void *in, |
902 | int index0, int index1, int index2, | |
903 | int index3); | |
4d3fa06f AP |
904 | void ecp_nistz256_avx2_transpose_convert(void *RESULTx4, const void *in); |
905 | void ecp_nistz256_avx2_convert_transpose_back(void *result, const void *Ax4); | |
906 | void ecp_nistz256_avx2_point_add_affine_x4(void *RESULTx4, const void *Ax4, | |
907 | const void *Bx4); | |
908 | void ecp_nistz256_avx2_point_add_affines_x4(void *RESULTx4, const void *Ax4, | |
909 | const void *Bx4); | |
910 | void ecp_nistz256_avx2_to_mont(void *RESULTx4, const void *Ax4); | |
911 | void ecp_nistz256_avx2_from_mont(void *RESULTx4, const void *Ax4); | |
912 | void ecp_nistz256_avx2_set1(void *RESULTx4); | |
913 | int ecp_nistz_avx2_eligible(void); | |
914 | ||
915 | static void booth_recode_w7(unsigned char *sign, | |
916 | unsigned char *digit, unsigned char in) | |
917 | { | |
918 | unsigned char s, d; | |
919 | ||
920 | s = ~((in >> 7) - 1); | |
921 | d = (1 << 8) - in - 1; | |
922 | d = (d & s) | (in & ~s); | |
923 | d = (d >> 1) + (d & 1); | |
924 | ||
925 | *sign = s & 1; | |
926 | *digit = d; | |
927 | } | |
928 | ||
20728adc AP |
929 | /* |
930 | * ecp_nistz256_avx2_mul_g performs multiplication by G, using only the | |
4d3fa06f | 931 | * precomputed table. It does 4 affine point additions in parallel, |
20728adc AP |
932 | * significantly speeding up point multiplication for a fixed value. |
933 | */ | |
58d47cf0 | 934 | static void ecp_nistz256_avx2_mul_g(P256_POINT *r, |
4d3fa06f | 935 | unsigned char p_str[33], |
58d47cf0 | 936 | const P256_POINT_AFFINE(*preComputedTable)[64]) |
4d3fa06f AP |
937 | { |
938 | const unsigned int window_size = 7; | |
939 | const unsigned int mask = (1 << (window_size + 1)) - 1; | |
940 | unsigned int wvalue; | |
941 | /* Using 4 windows at a time */ | |
942 | unsigned char sign0, digit0; | |
943 | unsigned char sign1, digit1; | |
944 | unsigned char sign2, digit2; | |
945 | unsigned char sign3, digit3; | |
49b05c7d | 946 | unsigned int idx = 0; |
4d3fa06f AP |
947 | BN_ULONG tmp[P256_LIMBS]; |
948 | int i; | |
949 | ||
950 | ALIGN32 BN_ULONG aX4[4 * 9 * 3] = { 0 }; | |
951 | ALIGN32 BN_ULONG bX4[4 * 9 * 2] = { 0 }; | |
3ff08e1d AP |
952 | ALIGN32 P256_POINT_AFFINE point_arr[4]; |
953 | ALIGN32 P256_POINT res_point_arr[4]; | |
4d3fa06f AP |
954 | |
955 | /* Initial four windows */ | |
956 | wvalue = *((u16 *) & p_str[0]); | |
957 | wvalue = (wvalue << 1) & mask; | |
49b05c7d | 958 | idx += window_size; |
4d3fa06f | 959 | booth_recode_w7(&sign0, &digit0, 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(&sign1, &digit1, wvalue); |
49b05c7d RS |
964 | wvalue = *((u16 *) & p_str[(idx - 1) / 8]); |
965 | wvalue = (wvalue >> ((idx - 1) % 8)) & mask; | |
966 | idx += window_size; | |
4d3fa06f | 967 | booth_recode_w7(&sign2, &digit2, wvalue); |
49b05c7d RS |
968 | wvalue = *((u16 *) & p_str[(idx - 1) / 8]); |
969 | wvalue = (wvalue >> ((idx - 1) % 8)) & mask; | |
970 | idx += window_size; | |
4d3fa06f AP |
971 | booth_recode_w7(&sign3, &digit3, wvalue); |
972 | ||
3ff08e1d | 973 | ecp_nistz256_avx2_multi_gather_w7(point_arr, preComputedTable[0], |
4d3fa06f AP |
974 | digit0, digit1, digit2, digit3); |
975 | ||
976 | ecp_nistz256_neg(tmp, point_arr[0].Y); | |
977 | copy_conditional(point_arr[0].Y, tmp, sign0); | |
978 | ecp_nistz256_neg(tmp, point_arr[1].Y); | |
979 | copy_conditional(point_arr[1].Y, tmp, sign1); | |
980 | ecp_nistz256_neg(tmp, point_arr[2].Y); | |
981 | copy_conditional(point_arr[2].Y, tmp, sign2); | |
982 | ecp_nistz256_neg(tmp, point_arr[3].Y); | |
983 | copy_conditional(point_arr[3].Y, tmp, sign3); | |
984 | ||
985 | ecp_nistz256_avx2_transpose_convert(aX4, point_arr); | |
986 | ecp_nistz256_avx2_to_mont(aX4, aX4); | |
987 | ecp_nistz256_avx2_to_mont(&aX4[4 * 9], &aX4[4 * 9]); | |
988 | ecp_nistz256_avx2_set1(&aX4[4 * 9 * 2]); | |
989 | ||
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(&sign0, &digit0, 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(&sign1, &digit1, wvalue); |
49b05c7d RS |
998 | wvalue = *((u16 *) & p_str[(idx - 1) / 8]); |
999 | wvalue = (wvalue >> ((idx - 1) % 8)) & mask; | |
1000 | idx += window_size; | |
4d3fa06f | 1001 | booth_recode_w7(&sign2, &digit2, wvalue); |
49b05c7d RS |
1002 | wvalue = *((u16 *) & p_str[(idx - 1) / 8]); |
1003 | wvalue = (wvalue >> ((idx - 1) % 8)) & mask; | |
1004 | idx += window_size; | |
4d3fa06f AP |
1005 | booth_recode_w7(&sign3, &digit3, wvalue); |
1006 | ||
3ff08e1d | 1007 | ecp_nistz256_avx2_multi_gather_w7(point_arr, preComputedTable[4 * 1], |
4d3fa06f AP |
1008 | digit0, digit1, digit2, digit3); |
1009 | ||
1010 | ecp_nistz256_neg(tmp, point_arr[0].Y); | |
1011 | copy_conditional(point_arr[0].Y, tmp, sign0); | |
1012 | ecp_nistz256_neg(tmp, point_arr[1].Y); | |
1013 | copy_conditional(point_arr[1].Y, tmp, sign1); | |
1014 | ecp_nistz256_neg(tmp, point_arr[2].Y); | |
1015 | copy_conditional(point_arr[2].Y, tmp, sign2); | |
1016 | ecp_nistz256_neg(tmp, point_arr[3].Y); | |
1017 | copy_conditional(point_arr[3].Y, tmp, sign3); | |
1018 | ||
1019 | ecp_nistz256_avx2_transpose_convert(bX4, point_arr); | |
1020 | ecp_nistz256_avx2_to_mont(bX4, bX4); | |
1021 | ecp_nistz256_avx2_to_mont(&bX4[4 * 9], &bX4[4 * 9]); | |
1022 | /* Optimized when both inputs are affine */ | |
1023 | ecp_nistz256_avx2_point_add_affines_x4(aX4, aX4, bX4); | |
1024 | ||
1025 | for (i = 2; i < 9; i++) { | |
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(&sign0, &digit0, 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(&sign1, &digit1, wvalue); |
49b05c7d RS |
1034 | wvalue = *((u16 *) & p_str[(idx - 1) / 8]); |
1035 | wvalue = (wvalue >> ((idx - 1) % 8)) & mask; | |
1036 | idx += window_size; | |
4d3fa06f | 1037 | booth_recode_w7(&sign2, &digit2, wvalue); |
49b05c7d RS |
1038 | wvalue = *((u16 *) & p_str[(idx - 1) / 8]); |
1039 | wvalue = (wvalue >> ((idx - 1) % 8)) & mask; | |
1040 | idx += window_size; | |
4d3fa06f AP |
1041 | booth_recode_w7(&sign3, &digit3, wvalue); |
1042 | ||
3ff08e1d | 1043 | ecp_nistz256_avx2_multi_gather_w7(point_arr, |
4d3fa06f AP |
1044 | preComputedTable[4 * i], |
1045 | digit0, digit1, digit2, digit3); | |
1046 | ||
1047 | ecp_nistz256_neg(tmp, point_arr[0].Y); | |
1048 | copy_conditional(point_arr[0].Y, tmp, sign0); | |
1049 | ecp_nistz256_neg(tmp, point_arr[1].Y); | |
1050 | copy_conditional(point_arr[1].Y, tmp, sign1); | |
1051 | ecp_nistz256_neg(tmp, point_arr[2].Y); | |
1052 | copy_conditional(point_arr[2].Y, tmp, sign2); | |
1053 | ecp_nistz256_neg(tmp, point_arr[3].Y); | |
1054 | copy_conditional(point_arr[3].Y, tmp, sign3); | |
1055 | ||
1056 | ecp_nistz256_avx2_transpose_convert(bX4, point_arr); | |
1057 | ecp_nistz256_avx2_to_mont(bX4, bX4); | |
1058 | ecp_nistz256_avx2_to_mont(&bX4[4 * 9], &bX4[4 * 9]); | |
1059 | ||
1060 | ecp_nistz256_avx2_point_add_affine_x4(aX4, aX4, bX4); | |
1061 | } | |
1062 | ||
1063 | ecp_nistz256_avx2_from_mont(&aX4[4 * 9 * 0], &aX4[4 * 9 * 0]); | |
1064 | ecp_nistz256_avx2_from_mont(&aX4[4 * 9 * 1], &aX4[4 * 9 * 1]); | |
1065 | ecp_nistz256_avx2_from_mont(&aX4[4 * 9 * 2], &aX4[4 * 9 * 2]); | |
1066 | ||
1067 | ecp_nistz256_avx2_convert_transpose_back(res_point_arr, aX4); | |
1068 | /* Last window is performed serially */ | |
49b05c7d RS |
1069 | wvalue = *((u16 *) & p_str[(idx - 1) / 8]); |
1070 | wvalue = (wvalue >> ((idx - 1) % 8)) & mask; | |
4d3fa06f | 1071 | booth_recode_w7(&sign0, &digit0, wvalue); |
58d47cf0 AP |
1072 | ecp_nistz256_gather_w7((P256_POINT_AFFINE *)r, |
1073 | preComputedTable[36], digit0); | |
4d3fa06f AP |
1074 | ecp_nistz256_neg(tmp, r->Y); |
1075 | copy_conditional(r->Y, tmp, sign0); | |
1076 | memcpy(r->Z, ONE, sizeof(ONE)); | |
1077 | /* Sum the four windows */ | |
1078 | ecp_nistz256_point_add(r, r, &res_point_arr[0]); | |
1079 | ecp_nistz256_point_add(r, r, &res_point_arr[1]); | |
1080 | ecp_nistz256_point_add(r, r, &res_point_arr[2]); | |
1081 | ecp_nistz256_point_add(r, r, &res_point_arr[3]); | |
1082 | } | |
1083 | # endif | |
1084 | #endif | |
1085 | ||
58d47cf0 AP |
1086 | static int ecp_nistz256_set_from_affine(EC_POINT *out, const EC_GROUP *group, |
1087 | const P256_POINT_AFFINE *in, | |
1088 | BN_CTX *ctx) | |
4d3fa06f | 1089 | { |
5784a521 | 1090 | BIGNUM *x, *y; |
4d3fa06f AP |
1091 | BN_ULONG d_x[P256_LIMBS], d_y[P256_LIMBS]; |
1092 | int ret = 0; | |
1093 | ||
5784a521 | 1094 | x = BN_new(); |
58d47cf0 | 1095 | if (!x) |
5784a521 MC |
1096 | return 0; |
1097 | y = BN_new(); | |
58d47cf0 | 1098 | if (!y) { |
5784a521 MC |
1099 | BN_free(x); |
1100 | return 0; | |
1101 | } | |
4d3fa06f | 1102 | memcpy(d_x, in->X, sizeof(d_x)); |
5784a521 | 1103 | bn_set_static_words(x, d_x, P256_LIMBS); |
4d3fa06f AP |
1104 | |
1105 | memcpy(d_y, in->Y, sizeof(d_y)); | |
5784a521 MC |
1106 | bn_set_static_words(y, d_y, P256_LIMBS); |
1107 | ||
1108 | ret = EC_POINT_set_affine_coordinates_GFp(group, out, x, y, ctx); | |
4d3fa06f | 1109 | |
58d47cf0 AP |
1110 | if (x) |
1111 | BN_free(x); | |
1112 | if (y) | |
1113 | BN_free(y); | |
4d3fa06f AP |
1114 | |
1115 | return ret; | |
1116 | } | |
1117 | ||
1118 | /* r = scalar*G + sum(scalars[i]*points[i]) */ | |
58d47cf0 AP |
1119 | static int ecp_nistz256_points_mul(const EC_GROUP *group, |
1120 | EC_POINT *r, | |
1121 | const BIGNUM *scalar, | |
4d3fa06f | 1122 | size_t num, |
58d47cf0 AP |
1123 | const EC_POINT *points[], |
1124 | const BIGNUM *scalars[], BN_CTX *ctx) | |
4d3fa06f AP |
1125 | { |
1126 | int i = 0, ret = 0, no_precomp_for_generator = 0, p_is_infinity = 0; | |
16e5b45f | 1127 | size_t j; |
4d3fa06f AP |
1128 | unsigned char p_str[33] = { 0 }; |
1129 | const PRECOMP256_ROW *preComputedTable = NULL; | |
1130 | const EC_PRE_COMP *pre_comp = NULL; | |
1131 | const EC_POINT *generator = NULL; | |
49b05c7d | 1132 | unsigned int idx = 0; |
4d3fa06f AP |
1133 | const unsigned int window_size = 7; |
1134 | const unsigned int mask = (1 << (window_size + 1)) - 1; | |
1135 | unsigned int wvalue; | |
1136 | ALIGN32 union { | |
1137 | P256_POINT p; | |
1138 | P256_POINT_AFFINE a; | |
1139 | } t, p; | |
1140 | BIGNUM *tmp_scalar; | |
1141 | ||
58d47cf0 | 1142 | if ((num + 1) == 0 || (num + 1) > OPENSSL_MALLOC_MAX_NELEMS(void *)) { |
3ff08e1d AP |
1143 | ECerr(EC_F_ECP_NISTZ256_POINTS_MUL, ERR_R_MALLOC_FAILURE); |
1144 | return 0; | |
1145 | } | |
1146 | ||
4d3fa06f | 1147 | if (group->meth != r->meth) { |
be07ae9b | 1148 | ECerr(EC_F_ECP_NISTZ256_POINTS_MUL, EC_R_INCOMPATIBLE_OBJECTS); |
4d3fa06f AP |
1149 | return 0; |
1150 | } | |
1151 | if ((scalar == NULL) && (num == 0)) | |
1152 | return EC_POINT_set_to_infinity(group, r); | |
1153 | ||
16e5b45f DSH |
1154 | for (j = 0; j < num; j++) { |
1155 | if (group->meth != points[j]->meth) { | |
be07ae9b | 1156 | ECerr(EC_F_ECP_NISTZ256_POINTS_MUL, EC_R_INCOMPATIBLE_OBJECTS); |
4d3fa06f AP |
1157 | return 0; |
1158 | } | |
1159 | } | |
1160 | ||
1161 | /* Need 256 bits for space for all coordinates. */ | |
5784a521 MC |
1162 | bn_wexpand(r->X, P256_LIMBS); |
1163 | bn_wexpand(r->Y, P256_LIMBS); | |
1164 | bn_wexpand(r->Z, P256_LIMBS); | |
1165 | bn_set_top(r->X, P256_LIMBS); | |
1166 | bn_set_top(r->Y, P256_LIMBS); | |
1167 | bn_set_top(r->Z, P256_LIMBS); | |
4d3fa06f AP |
1168 | |
1169 | if (scalar) { | |
1170 | generator = EC_GROUP_get0_generator(group); | |
1171 | if (generator == NULL) { | |
be07ae9b | 1172 | ECerr(EC_F_ECP_NISTZ256_POINTS_MUL, EC_R_UNDEFINED_GENERATOR); |
4d3fa06f AP |
1173 | goto err; |
1174 | } | |
1175 | ||
1176 | /* look if we can use precomputed multiples of generator */ | |
1177 | pre_comp = | |
be07ae9b AP |
1178 | EC_EX_DATA_get_data(group->extra_data, ecp_nistz256_pre_comp_dup, |
1179 | ecp_nistz256_pre_comp_free, | |
1180 | ecp_nistz256_pre_comp_clear_free); | |
4d3fa06f AP |
1181 | |
1182 | if (pre_comp) { | |
20728adc AP |
1183 | /* |
1184 | * If there is a precomputed table for the generator, check that | |
1185 | * it was generated with the same generator. | |
1186 | */ | |
4d3fa06f AP |
1187 | EC_POINT *pre_comp_generator = EC_POINT_new(group); |
1188 | if (pre_comp_generator == NULL) | |
1189 | goto err; | |
1190 | ||
3ff08e1d AP |
1191 | if (!ecp_nistz256_set_from_affine(pre_comp_generator, |
1192 | group, pre_comp->precomp[0], | |
1193 | ctx)) | |
4d3fa06f AP |
1194 | goto err; |
1195 | ||
1196 | if (0 == EC_POINT_cmp(group, generator, pre_comp_generator, ctx)) | |
1197 | preComputedTable = (const PRECOMP256_ROW *)pre_comp->precomp; | |
1198 | ||
1199 | EC_POINT_free(pre_comp_generator); | |
1200 | } | |
1201 | ||
1202 | if (preComputedTable == NULL && ecp_nistz256_is_affine_G(generator)) { | |
20728adc AP |
1203 | /* |
1204 | * If there is no precomputed data, but the generator is the | |
1205 | * default, a hardcoded table of precomputed data is used. This | |
1206 | * is because applications, such as Apache, do not use | |
1207 | * EC_KEY_precompute_mult. | |
1208 | */ | |
3ff08e1d | 1209 | preComputedTable = ecp_nistz256_precomputed; |
4d3fa06f AP |
1210 | } |
1211 | ||
1212 | if (preComputedTable) { | |
1213 | if ((BN_num_bits(scalar) > 256) | |
1214 | || BN_is_negative(scalar)) { | |
1215 | if ((tmp_scalar = BN_CTX_get(ctx)) == NULL) | |
1216 | goto err; | |
1217 | ||
5784a521 | 1218 | if (!BN_nnmod(tmp_scalar, scalar, group->order, ctx)) { |
be07ae9b | 1219 | ECerr(EC_F_ECP_NISTZ256_POINTS_MUL, ERR_R_BN_LIB); |
4d3fa06f AP |
1220 | goto err; |
1221 | } | |
1222 | scalar = tmp_scalar; | |
1223 | } | |
1224 | ||
5784a521 MC |
1225 | for (i = 0; i < bn_get_top(scalar) * BN_BYTES; i += BN_BYTES) { |
1226 | BN_ULONG d = bn_get_words(scalar)[i / BN_BYTES]; | |
4d3fa06f AP |
1227 | |
1228 | p_str[i + 0] = d & 0xff; | |
1229 | p_str[i + 1] = (d >> 8) & 0xff; | |
1230 | p_str[i + 2] = (d >> 16) & 0xff; | |
1231 | p_str[i + 3] = (d >>= 24) & 0xff; | |
1232 | if (BN_BYTES == 8) { | |
1233 | d >>= 8; | |
1234 | p_str[i + 4] = d & 0xff; | |
1235 | p_str[i + 5] = (d >> 8) & 0xff; | |
1236 | p_str[i + 6] = (d >> 16) & 0xff; | |
1237 | p_str[i + 7] = (d >> 24) & 0xff; | |
1238 | } | |
1239 | } | |
1240 | ||
1241 | for (; i < 33; i++) | |
1242 | p_str[i] = 0; | |
1243 | ||
1244 | #if defined(ECP_NISTZ256_AVX2) | |
1245 | if (ecp_nistz_avx2_eligible()) { | |
1246 | ecp_nistz256_avx2_mul_g(&p.p, p_str, preComputedTable); | |
1247 | } else | |
1248 | #endif | |
1249 | { | |
1250 | /* First window */ | |
1251 | wvalue = (p_str[0] << 1) & mask; | |
49b05c7d | 1252 | idx += window_size; |
4d3fa06f AP |
1253 | |
1254 | wvalue = _booth_recode_w7(wvalue); | |
1255 | ||
58d47cf0 AP |
1256 | ecp_nistz256_gather_w7(&p.a, preComputedTable[0], |
1257 | wvalue >> 1); | |
4d3fa06f AP |
1258 | |
1259 | ecp_nistz256_neg(p.p.Z, p.p.Y); | |
1260 | copy_conditional(p.p.Y, p.p.Z, wvalue & 1); | |
1261 | ||
1262 | memcpy(p.p.Z, ONE, sizeof(ONE)); | |
1263 | ||
1264 | for (i = 1; i < 37; i++) { | |
49b05c7d | 1265 | unsigned int off = (idx - 1) / 8; |
4d3fa06f | 1266 | wvalue = p_str[off] | p_str[off + 1] << 8; |
49b05c7d RS |
1267 | wvalue = (wvalue >> ((idx - 1) % 8)) & mask; |
1268 | idx += window_size; | |
4d3fa06f AP |
1269 | |
1270 | wvalue = _booth_recode_w7(wvalue); | |
1271 | ||
3ff08e1d | 1272 | ecp_nistz256_gather_w7(&t.a, |
4d3fa06f AP |
1273 | preComputedTable[i], wvalue >> 1); |
1274 | ||
1275 | ecp_nistz256_neg(t.p.Z, t.a.Y); | |
1276 | copy_conditional(t.a.Y, t.p.Z, wvalue & 1); | |
1277 | ||
1278 | ecp_nistz256_point_add_affine(&p.p, &p.p, &t.a); | |
1279 | } | |
1280 | } | |
1281 | } else { | |
1282 | p_is_infinity = 1; | |
1283 | no_precomp_for_generator = 1; | |
1284 | } | |
1285 | } else | |
1286 | p_is_infinity = 1; | |
1287 | ||
1288 | if (no_precomp_for_generator) { | |
20728adc AP |
1289 | /* |
1290 | * Without a precomputed table for the generator, it has to be | |
1291 | * handled like a normal point. | |
1292 | */ | |
4d3fa06f AP |
1293 | const BIGNUM **new_scalars; |
1294 | const EC_POINT **new_points; | |
1295 | ||
1296 | new_scalars = OPENSSL_malloc((num + 1) * sizeof(BIGNUM *)); | |
1297 | if (!new_scalars) { | |
be07ae9b | 1298 | ECerr(EC_F_ECP_NISTZ256_POINTS_MUL, ERR_R_MALLOC_FAILURE); |
4d3fa06f AP |
1299 | return 0; |
1300 | } | |
1301 | ||
1302 | new_points = OPENSSL_malloc((num + 1) * sizeof(EC_POINT *)); | |
1303 | if (!new_points) { | |
1304 | OPENSSL_free(new_scalars); | |
be07ae9b | 1305 | ECerr(EC_F_ECP_NISTZ256_POINTS_MUL, ERR_R_MALLOC_FAILURE); |
4d3fa06f AP |
1306 | return 0; |
1307 | } | |
1308 | ||
1309 | memcpy(new_scalars, scalars, num * sizeof(BIGNUM *)); | |
1310 | new_scalars[num] = scalar; | |
1311 | memcpy(new_points, points, num * sizeof(EC_POINT *)); | |
1312 | new_points[num] = generator; | |
1313 | ||
1314 | scalars = new_scalars; | |
1315 | points = new_points; | |
1316 | num++; | |
1317 | } | |
1318 | ||
1319 | if (num) { | |
1320 | P256_POINT *out = &t.p; | |
1321 | if (p_is_infinity) | |
1322 | out = &p.p; | |
1323 | ||
1324 | ecp_nistz256_windowed_mul(group, out, scalars, points, num, ctx); | |
1325 | ||
1326 | if (!p_is_infinity) | |
1327 | ecp_nistz256_point_add(&p.p, &p.p, out); | |
1328 | } | |
1329 | ||
1330 | if (no_precomp_for_generator) { | |
1331 | OPENSSL_free(points); | |
1332 | OPENSSL_free(scalars); | |
1333 | } | |
1334 | ||
5784a521 MC |
1335 | bn_set_data(r->X, p.p.X, sizeof(p.p.X)); |
1336 | bn_set_data(r->Y, p.p.Y, sizeof(p.p.Y)); | |
1337 | bn_set_data(r->Z, p.p.Z, sizeof(p.p.Z)); | |
1338 | bn_correct_top(r->X); | |
1339 | bn_correct_top(r->Y); | |
1340 | bn_correct_top(r->Z); | |
4d3fa06f AP |
1341 | |
1342 | ret = 1; | |
1343 | ||
58d47cf0 | 1344 | err: |
4d3fa06f AP |
1345 | return ret; |
1346 | } | |
1347 | ||
58d47cf0 AP |
1348 | static int ecp_nistz256_get_affine(const EC_GROUP *group, |
1349 | const EC_POINT *point, | |
1350 | BIGNUM *x, BIGNUM *y, BN_CTX *ctx) | |
4d3fa06f AP |
1351 | { |
1352 | BN_ULONG z_inv2[P256_LIMBS]; | |
1353 | BN_ULONG z_inv3[P256_LIMBS]; | |
1354 | BN_ULONG x_aff[P256_LIMBS]; | |
1355 | BN_ULONG y_aff[P256_LIMBS]; | |
1356 | BN_ULONG point_x[P256_LIMBS], point_y[P256_LIMBS], point_z[P256_LIMBS]; | |
1357 | ||
1358 | if (EC_POINT_is_at_infinity(group, point)) { | |
be07ae9b | 1359 | ECerr(EC_F_ECP_NISTZ256_GET_AFFINE, EC_R_POINT_AT_INFINITY); |
4d3fa06f AP |
1360 | return 0; |
1361 | } | |
1362 | ||
5784a521 MC |
1363 | if (!ecp_nistz256_bignum_to_field_elem(point_x, point->X) || |
1364 | !ecp_nistz256_bignum_to_field_elem(point_y, point->Y) || | |
1365 | !ecp_nistz256_bignum_to_field_elem(point_z, point->Z)) { | |
be07ae9b | 1366 | ECerr(EC_F_ECP_NISTZ256_GET_AFFINE, EC_R_COORDINATES_OUT_OF_RANGE); |
4d3fa06f AP |
1367 | return 0; |
1368 | } | |
1369 | ||
1370 | ecp_nistz256_mod_inverse(z_inv3, point_z); | |
1371 | ecp_nistz256_sqr_mont(z_inv2, z_inv3); | |
1372 | ecp_nistz256_mul_mont(x_aff, z_inv2, point_x); | |
1373 | ||
1374 | if (x != NULL) { | |
1375 | bn_wexpand(x, P256_LIMBS); | |
5784a521 MC |
1376 | bn_set_top(x, P256_LIMBS); |
1377 | ecp_nistz256_from_mont(bn_get_words(x), x_aff); | |
4d3fa06f AP |
1378 | bn_correct_top(x); |
1379 | } | |
1380 | ||
1381 | if (y != NULL) { | |
1382 | ecp_nistz256_mul_mont(z_inv3, z_inv3, z_inv2); | |
1383 | ecp_nistz256_mul_mont(y_aff, z_inv3, point_y); | |
1384 | bn_wexpand(y, P256_LIMBS); | |
5784a521 MC |
1385 | bn_set_top(y, P256_LIMBS); |
1386 | ecp_nistz256_from_mont(bn_get_words(y), y_aff); | |
4d3fa06f AP |
1387 | bn_correct_top(y); |
1388 | } | |
1389 | ||
1390 | return 1; | |
1391 | } | |
1392 | ||
58d47cf0 | 1393 | static EC_PRE_COMP *ecp_nistz256_pre_comp_new(const EC_GROUP *group) |
4d3fa06f AP |
1394 | { |
1395 | EC_PRE_COMP *ret = NULL; | |
1396 | ||
1397 | if (!group) | |
1398 | return NULL; | |
1399 | ||
58d47cf0 | 1400 | ret = (EC_PRE_COMP *)OPENSSL_malloc(sizeof(EC_PRE_COMP)); |
4d3fa06f AP |
1401 | |
1402 | if (!ret) { | |
be07ae9b | 1403 | ECerr(EC_F_ECP_NISTZ256_PRE_COMP_NEW, ERR_R_MALLOC_FAILURE); |
4d3fa06f AP |
1404 | return ret; |
1405 | } | |
1406 | ||
1407 | ret->group = group; | |
1408 | ret->w = 6; /* default */ | |
1409 | ret->precomp = NULL; | |
1410 | ret->precomp_storage = NULL; | |
1411 | ret->references = 1; | |
1412 | return ret; | |
1413 | } | |
1414 | ||
be07ae9b | 1415 | static void *ecp_nistz256_pre_comp_dup(void *src_) |
4d3fa06f AP |
1416 | { |
1417 | EC_PRE_COMP *src = src_; | |
1418 | ||
1419 | /* no need to actually copy, these objects never change! */ | |
1420 | CRYPTO_add(&src->references, 1, CRYPTO_LOCK_EC_PRE_COMP); | |
1421 | ||
1422 | return src_; | |
1423 | } | |
1424 | ||
be07ae9b | 1425 | static void ecp_nistz256_pre_comp_free(void *pre_) |
4d3fa06f AP |
1426 | { |
1427 | int i; | |
1428 | EC_PRE_COMP *pre = pre_; | |
1429 | ||
1430 | if (!pre) | |
1431 | return; | |
1432 | ||
1433 | i = CRYPTO_add(&pre->references, -1, CRYPTO_LOCK_EC_PRE_COMP); | |
1434 | if (i > 0) | |
1435 | return; | |
1436 | ||
1437 | if (pre->precomp_storage) | |
1438 | OPENSSL_free(pre->precomp_storage); | |
1439 | ||
1440 | OPENSSL_free(pre); | |
1441 | } | |
1442 | ||
be07ae9b | 1443 | static void ecp_nistz256_pre_comp_clear_free(void *pre_) |
4d3fa06f AP |
1444 | { |
1445 | int i; | |
1446 | EC_PRE_COMP *pre = pre_; | |
1447 | ||
1448 | if (!pre) | |
1449 | return; | |
1450 | ||
1451 | i = CRYPTO_add(&pre->references, -1, CRYPTO_LOCK_EC_PRE_COMP); | |
1452 | if (i > 0) | |
1453 | return; | |
1454 | ||
1455 | if (pre->precomp_storage) { | |
1456 | OPENSSL_cleanse(pre->precomp, | |
1457 | 32 * sizeof(unsigned char) * (1 << pre->w) * 2 * 37); | |
1458 | OPENSSL_free(pre->precomp_storage); | |
1459 | } | |
1460 | OPENSSL_cleanse(pre, sizeof *pre); | |
1461 | OPENSSL_free(pre); | |
1462 | } | |
1463 | ||
58d47cf0 | 1464 | static int ecp_nistz256_window_have_precompute_mult(const EC_GROUP *group) |
4d3fa06f AP |
1465 | { |
1466 | /* There is a hard-coded table for the default generator. */ | |
1467 | const EC_POINT *generator = EC_GROUP_get0_generator(group); | |
1468 | if (generator != NULL && ecp_nistz256_is_affine_G(generator)) { | |
1469 | /* There is a hard-coded table for the default generator. */ | |
1470 | return 1; | |
1471 | } | |
1472 | ||
be07ae9b AP |
1473 | return EC_EX_DATA_get_data(group->extra_data, ecp_nistz256_pre_comp_dup, |
1474 | ecp_nistz256_pre_comp_free, | |
1475 | ecp_nistz256_pre_comp_clear_free) != NULL; | |
4d3fa06f AP |
1476 | } |
1477 | ||
1478 | const EC_METHOD *EC_GFp_nistz256_method(void) | |
1479 | { | |
1480 | static const EC_METHOD ret = { | |
1481 | EC_FLAGS_DEFAULT_OCT, | |
1482 | NID_X9_62_prime_field, | |
1483 | ec_GFp_mont_group_init, | |
1484 | ec_GFp_mont_group_finish, | |
1485 | ec_GFp_mont_group_clear_finish, | |
1486 | ec_GFp_mont_group_copy, | |
1487 | ec_GFp_mont_group_set_curve, | |
1488 | ec_GFp_simple_group_get_curve, | |
1489 | ec_GFp_simple_group_get_degree, | |
1490 | ec_GFp_simple_group_check_discriminant, | |
1491 | ec_GFp_simple_point_init, | |
1492 | ec_GFp_simple_point_finish, | |
1493 | ec_GFp_simple_point_clear_finish, | |
1494 | ec_GFp_simple_point_copy, | |
1495 | ec_GFp_simple_point_set_to_infinity, | |
1496 | ec_GFp_simple_set_Jprojective_coordinates_GFp, | |
1497 | ec_GFp_simple_get_Jprojective_coordinates_GFp, | |
1498 | ec_GFp_simple_point_set_affine_coordinates, | |
1499 | ecp_nistz256_get_affine, | |
1500 | 0, 0, 0, | |
1501 | ec_GFp_simple_add, | |
1502 | ec_GFp_simple_dbl, | |
1503 | ec_GFp_simple_invert, | |
1504 | ec_GFp_simple_is_at_infinity, | |
1505 | ec_GFp_simple_is_on_curve, | |
1506 | ec_GFp_simple_cmp, | |
1507 | ec_GFp_simple_make_affine, | |
1508 | ec_GFp_simple_points_make_affine, | |
1509 | ecp_nistz256_points_mul, /* mul */ | |
1510 | ecp_nistz256_mult_precompute, /* precompute_mult */ | |
1511 | ecp_nistz256_window_have_precompute_mult, /* have_precompute_mult */ | |
1512 | ec_GFp_mont_field_mul, | |
1513 | ec_GFp_mont_field_sqr, | |
1514 | 0, /* field_div */ | |
1515 | ec_GFp_mont_field_encode, | |
1516 | ec_GFp_mont_field_decode, | |
1517 | ec_GFp_mont_field_set_to_one | |
1518 | }; | |
1519 | ||
1520 | return &ret; | |
1521 | } |