2 * Copyright 2010-2019 The OpenSSL Project Authors. All Rights Reserved.
4 * Licensed under the OpenSSL license (the "License"). You may not use
5 * this file except in compliance with the License. You can obtain a copy
6 * in the file LICENSE in the source distribution or at
7 * https://www.openssl.org/source/license.html
10 /* Copyright 2011 Google Inc.
12 * Licensed under the Apache License, Version 2.0 (the "License");
14 * you may not use this file except in compliance with the License.
15 * You may obtain a copy of the License at
17 * http://www.apache.org/licenses/LICENSE-2.0
19 * Unless required by applicable law or agreed to in writing, software
20 * distributed under the License is distributed on an "AS IS" BASIS,
21 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
22 * See the License for the specific language governing permissions and
23 * limitations under the License.
27 * A 64-bit implementation of the NIST P-224 elliptic curve point multiplication
29 * Inspired by Daniel J. Bernstein's public domain nistp224 implementation
30 * and Adam Langley's public domain 64-bit C implementation of curve25519
33 #include <openssl/opensslconf.h>
34 #ifdef OPENSSL_NO_EC_NISTP_64_GCC_128
35 NON_EMPTY_TRANSLATION_UNIT
40 # include <openssl/err.h>
41 # include "ec_local.h"
43 # if defined(__SIZEOF_INT128__) && __SIZEOF_INT128__==16
44 /* even with gcc, the typedef won't work for 32-bit platforms */
45 typedef __uint128_t uint128_t
; /* nonstandard; implemented by gcc on 64-bit
48 # error "Your compiler doesn't appear to support 128-bit integer types"
54 /******************************************************************************/
56 * INTERNAL REPRESENTATION OF FIELD ELEMENTS
58 * Field elements are represented as a_0 + 2^56*a_1 + 2^112*a_2 + 2^168*a_3
59 * using 64-bit coefficients called 'limbs',
60 * and sometimes (for multiplication results) as
61 * b_0 + 2^56*b_1 + 2^112*b_2 + 2^168*b_3 + 2^224*b_4 + 2^280*b_5 + 2^336*b_6
62 * using 128-bit coefficients called 'widelimbs'.
63 * A 4-limb representation is an 'felem';
64 * a 7-widelimb representation is a 'widefelem'.
65 * Even within felems, bits of adjacent limbs overlap, and we don't always
66 * reduce the representations: we ensure that inputs to each felem
67 * multiplication satisfy a_i < 2^60, so outputs satisfy b_i < 4*2^60*2^60,
68 * and fit into a 128-bit word without overflow. The coefficients are then
69 * again partially reduced to obtain an felem satisfying a_i < 2^57.
70 * We only reduce to the unique minimal representation at the end of the
74 typedef uint64_t limb
;
75 typedef uint128_t widelimb
;
77 typedef limb felem
[4];
78 typedef widelimb widefelem
[7];
81 * Field element represented as a byte array. 28*8 = 224 bits is also the
82 * group order size for the elliptic curve, and we also use this type for
83 * scalars for point multiplication.
85 typedef u8 felem_bytearray
[28];
87 static const felem_bytearray nistp224_curve_params
[5] = {
88 {0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, /* p */
89 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0x00, 0x00, 0x00, 0x00,
90 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x01},
91 {0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, /* a */
92 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFE, 0xFF, 0xFF, 0xFF, 0xFF,
93 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFE},
94 {0xB4, 0x05, 0x0A, 0x85, 0x0C, 0x04, 0xB3, 0xAB, 0xF5, 0x41, /* b */
95 0x32, 0x56, 0x50, 0x44, 0xB0, 0xB7, 0xD7, 0xBF, 0xD8, 0xBA,
96 0x27, 0x0B, 0x39, 0x43, 0x23, 0x55, 0xFF, 0xB4},
97 {0xB7, 0x0E, 0x0C, 0xBD, 0x6B, 0xB4, 0xBF, 0x7F, 0x32, 0x13, /* x */
98 0x90, 0xB9, 0x4A, 0x03, 0xC1, 0xD3, 0x56, 0xC2, 0x11, 0x22,
99 0x34, 0x32, 0x80, 0xD6, 0x11, 0x5C, 0x1D, 0x21},
100 {0xbd, 0x37, 0x63, 0x88, 0xb5, 0xf7, 0x23, 0xfb, 0x4c, 0x22, /* y */
101 0xdf, 0xe6, 0xcd, 0x43, 0x75, 0xa0, 0x5a, 0x07, 0x47, 0x64,
102 0x44, 0xd5, 0x81, 0x99, 0x85, 0x00, 0x7e, 0x34}
106 * Precomputed multiples of the standard generator
107 * Points are given in coordinates (X, Y, Z) where Z normally is 1
108 * (0 for the point at infinity).
109 * For each field element, slice a_0 is word 0, etc.
111 * The table has 2 * 16 elements, starting with the following:
112 * index | bits | point
113 * ------+---------+------------------------------
116 * 2 | 0 0 1 0 | 2^56G
117 * 3 | 0 0 1 1 | (2^56 + 1)G
118 * 4 | 0 1 0 0 | 2^112G
119 * 5 | 0 1 0 1 | (2^112 + 1)G
120 * 6 | 0 1 1 0 | (2^112 + 2^56)G
121 * 7 | 0 1 1 1 | (2^112 + 2^56 + 1)G
122 * 8 | 1 0 0 0 | 2^168G
123 * 9 | 1 0 0 1 | (2^168 + 1)G
124 * 10 | 1 0 1 0 | (2^168 + 2^56)G
125 * 11 | 1 0 1 1 | (2^168 + 2^56 + 1)G
126 * 12 | 1 1 0 0 | (2^168 + 2^112)G
127 * 13 | 1 1 0 1 | (2^168 + 2^112 + 1)G
128 * 14 | 1 1 1 0 | (2^168 + 2^112 + 2^56)G
129 * 15 | 1 1 1 1 | (2^168 + 2^112 + 2^56 + 1)G
130 * followed by a copy of this with each element multiplied by 2^28.
132 * The reason for this is so that we can clock bits into four different
133 * locations when doing simple scalar multiplies against the base point,
134 * and then another four locations using the second 16 elements.
136 static const felem gmul
[2][16][3] = {
140 {{0x3280d6115c1d21, 0xc1d356c2112234, 0x7f321390b94a03, 0xb70e0cbd6bb4bf},
141 {0xd5819985007e34, 0x75a05a07476444, 0xfb4c22dfe6cd43, 0xbd376388b5f723},
143 {{0xfd9675666ebbe9, 0xbca7664d40ce5e, 0x2242df8d8a2a43, 0x1f49bbb0f99bc5},
144 {0x29e0b892dc9c43, 0xece8608436e662, 0xdc858f185310d0, 0x9812dd4eb8d321},
146 {{0x6d3e678d5d8eb8, 0x559eed1cb362f1, 0x16e9a3bbce8a3f, 0xeedcccd8c2a748},
147 {0xf19f90ed50266d, 0xabf2b4bf65f9df, 0x313865468fafec, 0x5cb379ba910a17},
149 {{0x0641966cab26e3, 0x91fb2991fab0a0, 0xefec27a4e13a0b, 0x0499aa8a5f8ebe},
150 {0x7510407766af5d, 0x84d929610d5450, 0x81d77aae82f706, 0x6916f6d4338c5b},
152 {{0xea95ac3b1f15c6, 0x086000905e82d4, 0xdd323ae4d1c8b1, 0x932b56be7685a3},
153 {0x9ef93dea25dbbf, 0x41665960f390f0, 0xfdec76dbe2a8a7, 0x523e80f019062a},
155 {{0x822fdd26732c73, 0xa01c83531b5d0f, 0x363f37347c1ba4, 0xc391b45c84725c},
156 {0xbbd5e1b2d6ad24, 0xddfbcde19dfaec, 0xc393da7e222a7f, 0x1efb7890ede244},
158 {{0x4c9e90ca217da1, 0xd11beca79159bb, 0xff8d33c2c98b7c, 0x2610b39409f849},
159 {0x44d1352ac64da0, 0xcdbb7b2c46b4fb, 0x966c079b753c89, 0xfe67e4e820b112},
161 {{0xe28cae2df5312d, 0xc71b61d16f5c6e, 0x79b7619a3e7c4c, 0x05c73240899b47},
162 {0x9f7f6382c73e3a, 0x18615165c56bda, 0x641fab2116fd56, 0x72855882b08394},
164 {{0x0469182f161c09, 0x74a98ca8d00fb5, 0xb89da93489a3e0, 0x41c98768fb0c1d},
165 {0xe5ea05fb32da81, 0x3dce9ffbca6855, 0x1cfe2d3fbf59e6, 0x0e5e03408738a7},
167 {{0xdab22b2333e87f, 0x4430137a5dd2f6, 0xe03ab9f738beb8, 0xcb0c5d0dc34f24},
168 {0x764a7df0c8fda5, 0x185ba5c3fa2044, 0x9281d688bcbe50, 0xc40331df893881},
170 {{0xb89530796f0f60, 0xade92bd26909a3, 0x1a0c83fb4884da, 0x1765bf22a5a984},
171 {0x772a9ee75db09e, 0x23bc6c67cec16f, 0x4c1edba8b14e2f, 0xe2a215d9611369},
173 {{0x571e509fb5efb3, 0xade88696410552, 0xc8ae85fada74fe, 0x6c7e4be83bbde3},
174 {0xff9f51160f4652, 0xb47ce2495a6539, 0xa2946c53b582f4, 0x286d2db3ee9a60},
176 {{0x40bbd5081a44af, 0x0995183b13926c, 0xbcefba6f47f6d0, 0x215619e9cc0057},
177 {0x8bc94d3b0df45e, 0xf11c54a3694f6f, 0x8631b93cdfe8b5, 0xe7e3f4b0982db9},
179 {{0xb17048ab3e1c7b, 0xac38f36ff8a1d8, 0x1c29819435d2c6, 0xc813132f4c07e9},
180 {0x2891425503b11f, 0x08781030579fea, 0xf5426ba5cc9674, 0x1e28ebf18562bc},
182 {{0x9f31997cc864eb, 0x06cd91d28b5e4c, 0xff17036691a973, 0xf1aef351497c58},
183 {0xdd1f2d600564ff, 0xdead073b1402db, 0x74a684435bd693, 0xeea7471f962558},
188 {{0x9665266dddf554, 0x9613d78b60ef2d, 0xce27a34cdba417, 0xd35ab74d6afc31},
189 {0x85ccdd22deb15e, 0x2137e5783a6aab, 0xa141cffd8c93c6, 0x355a1830e90f2d},
191 {{0x1a494eadaade65, 0xd6da4da77fe53c, 0xe7992996abec86, 0x65c3553c6090e3},
192 {0xfa610b1fb09346, 0xf1c6540b8a4aaf, 0xc51a13ccd3cbab, 0x02995b1b18c28a},
194 {{0x7874568e7295ef, 0x86b419fbe38d04, 0xdc0690a7550d9a, 0xd3966a44beac33},
195 {0x2b7280ec29132f, 0xbeaa3b6a032df3, 0xdc7dd88ae41200, 0xd25e2513e3a100},
197 {{0x924857eb2efafd, 0xac2bce41223190, 0x8edaa1445553fc, 0x825800fd3562d5},
198 {0x8d79148ea96621, 0x23a01c3dd9ed8d, 0xaf8b219f9416b5, 0xd8db0cc277daea},
200 {{0x76a9c3b1a700f0, 0xe9acd29bc7e691, 0x69212d1a6b0327, 0x6322e97fe154be},
201 {0x469fc5465d62aa, 0x8d41ed18883b05, 0x1f8eae66c52b88, 0xe4fcbe9325be51},
203 {{0x825fdf583cac16, 0x020b857c7b023a, 0x683c17744b0165, 0x14ffd0a2daf2f1},
204 {0x323b36184218f9, 0x4944ec4e3b47d4, 0xc15b3080841acf, 0x0bced4b01a28bb},
206 {{0x92ac22230df5c4, 0x52f33b4063eda8, 0xcb3f19870c0c93, 0x40064f2ba65233},
207 {0xfe16f0924f8992, 0x012da25af5b517, 0x1a57bb24f723a6, 0x06f8bc76760def},
209 {{0x4a7084f7817cb9, 0xbcab0738ee9a78, 0x3ec11e11d9c326, 0xdc0fe90e0f1aae},
210 {0xcf639ea5f98390, 0x5c350aa22ffb74, 0x9afae98a4047b7, 0x956ec2d617fc45},
212 {{0x4306d648c1be6a, 0x9247cd8bc9a462, 0xf5595e377d2f2e, 0xbd1c3caff1a52e},
213 {0x045e14472409d0, 0x29f3e17078f773, 0x745a602b2d4f7d, 0x191837685cdfbb},
215 {{0x5b6ee254a8cb79, 0x4953433f5e7026, 0xe21faeb1d1def4, 0xc4c225785c09de},
216 {0x307ce7bba1e518, 0x31b125b1036db8, 0x47e91868839e8f, 0xc765866e33b9f3},
218 {{0x3bfece24f96906, 0x4794da641e5093, 0xde5df64f95db26, 0x297ecd89714b05},
219 {0x701bd3ebb2c3aa, 0x7073b4f53cb1d5, 0x13c5665658af16, 0x9895089d66fe58},
221 {{0x0fef05f78c4790, 0x2d773633b05d2e, 0x94229c3a951c94, 0xbbbd70df4911bb},
222 {0xb2c6963d2c1168, 0x105f47a72b0d73, 0x9fdf6111614080, 0x7b7e94b39e67b0},
224 {{0xad1a7d6efbe2b3, 0xf012482c0da69d, 0x6b3bdf12438345, 0x40d7558d7aa4d9},
225 {0x8a09fffb5c6d3d, 0x9a356e5d9ffd38, 0x5973f15f4f9b1c, 0xdcd5f59f63c3ea},
227 {{0xacf39f4c5ca7ab, 0x4c8071cc5fd737, 0xc64e3602cd1184, 0x0acd4644c9abba},
228 {0x6c011a36d8bf6e, 0xfecd87ba24e32a, 0x19f6f56574fad8, 0x050b204ced9405},
230 {{0xed4f1cae7d9a96, 0x5ceef7ad94c40a, 0x778e4a3bf3ef9b, 0x7405783dc3b55e},
231 {0x32477c61b6e8c6, 0xb46a97570f018b, 0x91176d0a7e95d1, 0x3df90fbc4c7d0e},
235 /* Precomputation for the group generator. */
236 struct nistp224_pre_comp_st
{
237 felem g_pre_comp
[2][16][3];
238 CRYPTO_REF_COUNT references
;
242 const EC_METHOD
*EC_GFp_nistp224_method(void)
244 static const EC_METHOD ret
= {
245 EC_FLAGS_DEFAULT_OCT
,
246 NID_X9_62_prime_field
,
247 ec_GFp_nistp224_group_init
,
248 ec_GFp_simple_group_finish
,
249 ec_GFp_simple_group_clear_finish
,
250 ec_GFp_nist_group_copy
,
251 ec_GFp_nistp224_group_set_curve
,
252 ec_GFp_simple_group_get_curve
,
253 ec_GFp_simple_group_get_degree
,
254 ec_group_simple_order_bits
,
255 ec_GFp_simple_group_check_discriminant
,
256 ec_GFp_simple_point_init
,
257 ec_GFp_simple_point_finish
,
258 ec_GFp_simple_point_clear_finish
,
259 ec_GFp_simple_point_copy
,
260 ec_GFp_simple_point_set_to_infinity
,
261 ec_GFp_simple_set_Jprojective_coordinates_GFp
,
262 ec_GFp_simple_get_Jprojective_coordinates_GFp
,
263 ec_GFp_simple_point_set_affine_coordinates
,
264 ec_GFp_nistp224_point_get_affine_coordinates
,
265 0 /* point_set_compressed_coordinates */ ,
270 ec_GFp_simple_invert
,
271 ec_GFp_simple_is_at_infinity
,
272 ec_GFp_simple_is_on_curve
,
274 ec_GFp_simple_make_affine
,
275 ec_GFp_simple_points_make_affine
,
276 ec_GFp_nistp224_points_mul
,
277 ec_GFp_nistp224_precompute_mult
,
278 ec_GFp_nistp224_have_precompute_mult
,
279 ec_GFp_nist_field_mul
,
280 ec_GFp_nist_field_sqr
,
282 ec_GFp_simple_field_inv
,
283 0 /* field_encode */ ,
284 0 /* field_decode */ ,
285 0, /* field_set_to_one */
286 ec_key_simple_priv2oct
,
287 ec_key_simple_oct2priv
,
289 ec_key_simple_generate_key
,
290 ec_key_simple_check_key
,
291 ec_key_simple_generate_public_key
,
294 ecdh_simple_compute_key
,
295 0, /* field_inverse_mod_ord */
296 0, /* blind_coordinates */
306 * Helper functions to convert field elements to/from internal representation
308 static void bin28_to_felem(felem out
, const u8 in
[28])
310 out
[0] = *((const uint64_t *)(in
)) & 0x00ffffffffffffff;
311 out
[1] = (*((const uint64_t *)(in
+ 7))) & 0x00ffffffffffffff;
312 out
[2] = (*((const uint64_t *)(in
+ 14))) & 0x00ffffffffffffff;
313 out
[3] = (*((const uint64_t *)(in
+20))) >> 8;
316 static void felem_to_bin28(u8 out
[28], const felem in
)
319 for (i
= 0; i
< 7; ++i
) {
320 out
[i
] = in
[0] >> (8 * i
);
321 out
[i
+ 7] = in
[1] >> (8 * i
);
322 out
[i
+ 14] = in
[2] >> (8 * i
);
323 out
[i
+ 21] = in
[3] >> (8 * i
);
327 /* From OpenSSL BIGNUM to internal representation */
328 static int BN_to_felem(felem out
, const BIGNUM
*bn
)
330 felem_bytearray b_out
;
333 if (BN_is_negative(bn
)) {
334 ECerr(EC_F_BN_TO_FELEM
, EC_R_BIGNUM_OUT_OF_RANGE
);
337 num_bytes
= BN_bn2lebinpad(bn
, b_out
, sizeof(b_out
));
339 ECerr(EC_F_BN_TO_FELEM
, EC_R_BIGNUM_OUT_OF_RANGE
);
342 bin28_to_felem(out
, b_out
);
346 /* From internal representation to OpenSSL BIGNUM */
347 static BIGNUM
*felem_to_BN(BIGNUM
*out
, const felem in
)
349 felem_bytearray b_out
;
350 felem_to_bin28(b_out
, in
);
351 return BN_lebin2bn(b_out
, sizeof(b_out
), out
);
354 /******************************************************************************/
358 * Field operations, using the internal representation of field elements.
359 * NB! These operations are specific to our point multiplication and cannot be
360 * expected to be correct in general - e.g., multiplication with a large scalar
361 * will cause an overflow.
365 static void felem_one(felem out
)
373 static void felem_assign(felem out
, const felem in
)
381 /* Sum two field elements: out += in */
382 static void felem_sum(felem out
, const felem in
)
390 /* Subtract field elements: out -= in */
391 /* Assumes in[i] < 2^57 */
392 static void felem_diff(felem out
, const felem in
)
394 static const limb two58p2
= (((limb
) 1) << 58) + (((limb
) 1) << 2);
395 static const limb two58m2
= (((limb
) 1) << 58) - (((limb
) 1) << 2);
396 static const limb two58m42m2
= (((limb
) 1) << 58) -
397 (((limb
) 1) << 42) - (((limb
) 1) << 2);
399 /* Add 0 mod 2^224-2^96+1 to ensure out > in */
401 out
[1] += two58m42m2
;
411 /* Subtract in unreduced 128-bit mode: out -= in */
412 /* Assumes in[i] < 2^119 */
413 static void widefelem_diff(widefelem out
, const widefelem in
)
415 static const widelimb two120
= ((widelimb
) 1) << 120;
416 static const widelimb two120m64
= (((widelimb
) 1) << 120) -
417 (((widelimb
) 1) << 64);
418 static const widelimb two120m104m64
= (((widelimb
) 1) << 120) -
419 (((widelimb
) 1) << 104) - (((widelimb
) 1) << 64);
421 /* Add 0 mod 2^224-2^96+1 to ensure out > in */
426 out
[4] += two120m104m64
;
439 /* Subtract in mixed mode: out128 -= in64 */
441 static void felem_diff_128_64(widefelem out
, const felem in
)
443 static const widelimb two64p8
= (((widelimb
) 1) << 64) +
444 (((widelimb
) 1) << 8);
445 static const widelimb two64m8
= (((widelimb
) 1) << 64) -
446 (((widelimb
) 1) << 8);
447 static const widelimb two64m48m8
= (((widelimb
) 1) << 64) -
448 (((widelimb
) 1) << 48) - (((widelimb
) 1) << 8);
450 /* Add 0 mod 2^224-2^96+1 to ensure out > in */
452 out
[1] += two64m48m8
;
463 * Multiply a field element by a scalar: out = out * scalar The scalars we
464 * actually use are small, so results fit without overflow
466 static void felem_scalar(felem out
, const limb scalar
)
475 * Multiply an unreduced field element by a scalar: out = out * scalar The
476 * scalars we actually use are small, so results fit without overflow
478 static void widefelem_scalar(widefelem out
, const widelimb scalar
)
489 /* Square a field element: out = in^2 */
490 static void felem_square(widefelem out
, const felem in
)
492 limb tmp0
, tmp1
, tmp2
;
496 out
[0] = ((widelimb
) in
[0]) * in
[0];
497 out
[1] = ((widelimb
) in
[0]) * tmp1
;
498 out
[2] = ((widelimb
) in
[0]) * tmp2
+ ((widelimb
) in
[1]) * in
[1];
499 out
[3] = ((widelimb
) in
[3]) * tmp0
+ ((widelimb
) in
[1]) * tmp2
;
500 out
[4] = ((widelimb
) in
[3]) * tmp1
+ ((widelimb
) in
[2]) * in
[2];
501 out
[5] = ((widelimb
) in
[3]) * tmp2
;
502 out
[6] = ((widelimb
) in
[3]) * in
[3];
505 /* Multiply two field elements: out = in1 * in2 */
506 static void felem_mul(widefelem out
, const felem in1
, const felem in2
)
508 out
[0] = ((widelimb
) in1
[0]) * in2
[0];
509 out
[1] = ((widelimb
) in1
[0]) * in2
[1] + ((widelimb
) in1
[1]) * in2
[0];
510 out
[2] = ((widelimb
) in1
[0]) * in2
[2] + ((widelimb
) in1
[1]) * in2
[1] +
511 ((widelimb
) in1
[2]) * in2
[0];
512 out
[3] = ((widelimb
) in1
[0]) * in2
[3] + ((widelimb
) in1
[1]) * in2
[2] +
513 ((widelimb
) in1
[2]) * in2
[1] + ((widelimb
) in1
[3]) * in2
[0];
514 out
[4] = ((widelimb
) in1
[1]) * in2
[3] + ((widelimb
) in1
[2]) * in2
[2] +
515 ((widelimb
) in1
[3]) * in2
[1];
516 out
[5] = ((widelimb
) in1
[2]) * in2
[3] + ((widelimb
) in1
[3]) * in2
[2];
517 out
[6] = ((widelimb
) in1
[3]) * in2
[3];
521 * Reduce seven 128-bit coefficients to four 64-bit coefficients.
522 * Requires in[i] < 2^126,
523 * ensures out[0] < 2^56, out[1] < 2^56, out[2] < 2^56, out[3] <= 2^56 + 2^16 */
524 static void felem_reduce(felem out
, const widefelem in
)
526 static const widelimb two127p15
= (((widelimb
) 1) << 127) +
527 (((widelimb
) 1) << 15);
528 static const widelimb two127m71
= (((widelimb
) 1) << 127) -
529 (((widelimb
) 1) << 71);
530 static const widelimb two127m71m55
= (((widelimb
) 1) << 127) -
531 (((widelimb
) 1) << 71) - (((widelimb
) 1) << 55);
534 /* Add 0 mod 2^224-2^96+1 to ensure all differences are positive */
535 output
[0] = in
[0] + two127p15
;
536 output
[1] = in
[1] + two127m71m55
;
537 output
[2] = in
[2] + two127m71
;
541 /* Eliminate in[4], in[5], in[6] */
542 output
[4] += in
[6] >> 16;
543 output
[3] += (in
[6] & 0xffff) << 40;
546 output
[3] += in
[5] >> 16;
547 output
[2] += (in
[5] & 0xffff) << 40;
550 output
[2] += output
[4] >> 16;
551 output
[1] += (output
[4] & 0xffff) << 40;
552 output
[0] -= output
[4];
554 /* Carry 2 -> 3 -> 4 */
555 output
[3] += output
[2] >> 56;
556 output
[2] &= 0x00ffffffffffffff;
558 output
[4] = output
[3] >> 56;
559 output
[3] &= 0x00ffffffffffffff;
561 /* Now output[2] < 2^56, output[3] < 2^56, output[4] < 2^72 */
563 /* Eliminate output[4] */
564 output
[2] += output
[4] >> 16;
565 /* output[2] < 2^56 + 2^56 = 2^57 */
566 output
[1] += (output
[4] & 0xffff) << 40;
567 output
[0] -= output
[4];
569 /* Carry 0 -> 1 -> 2 -> 3 */
570 output
[1] += output
[0] >> 56;
571 out
[0] = output
[0] & 0x00ffffffffffffff;
573 output
[2] += output
[1] >> 56;
574 /* output[2] < 2^57 + 2^72 */
575 out
[1] = output
[1] & 0x00ffffffffffffff;
576 output
[3] += output
[2] >> 56;
577 /* output[3] <= 2^56 + 2^16 */
578 out
[2] = output
[2] & 0x00ffffffffffffff;
581 * out[0] < 2^56, out[1] < 2^56, out[2] < 2^56,
582 * out[3] <= 2^56 + 2^16 (due to final carry),
588 static void felem_square_reduce(felem out
, const felem in
)
591 felem_square(tmp
, in
);
592 felem_reduce(out
, tmp
);
595 static void felem_mul_reduce(felem out
, const felem in1
, const felem in2
)
598 felem_mul(tmp
, in1
, in2
);
599 felem_reduce(out
, tmp
);
603 * Reduce to unique minimal representation. Requires 0 <= in < 2*p (always
604 * call felem_reduce first)
606 static void felem_contract(felem out
, const felem in
)
608 static const int64_t two56
= ((limb
) 1) << 56;
609 /* 0 <= in < 2*p, p = 2^224 - 2^96 + 1 */
610 /* if in > p , reduce in = in - 2^224 + 2^96 - 1 */
616 /* Case 1: a = 1 iff in >= 2^224 */
620 tmp
[3] &= 0x00ffffffffffffff;
622 * Case 2: a = 0 iff p <= in < 2^224, i.e., the high 128 bits are all 1
623 * and the lower part is non-zero
625 a
= ((in
[3] & in
[2] & (in
[1] | 0x000000ffffffffff)) + 1) |
626 (((int64_t) (in
[0] + (in
[1] & 0x000000ffffffffff)) - 1) >> 63);
627 a
&= 0x00ffffffffffffff;
628 /* turn a into an all-one mask (if a = 0) or an all-zero mask */
630 /* subtract 2^224 - 2^96 + 1 if a is all-one */
631 tmp
[3] &= a
^ 0xffffffffffffffff;
632 tmp
[2] &= a
^ 0xffffffffffffffff;
633 tmp
[1] &= (a
^ 0xffffffffffffffff) | 0x000000ffffffffff;
637 * eliminate negative coefficients: if tmp[0] is negative, tmp[1] must be
638 * non-zero, so we only need one step
644 /* carry 1 -> 2 -> 3 */
645 tmp
[2] += tmp
[1] >> 56;
646 tmp
[1] &= 0x00ffffffffffffff;
648 tmp
[3] += tmp
[2] >> 56;
649 tmp
[2] &= 0x00ffffffffffffff;
651 /* Now 0 <= out < p */
659 * Get negative value: out = -in
660 * Requires in[i] < 2^63,
661 * ensures out[0] < 2^56, out[1] < 2^56, out[2] < 2^56, out[3] <= 2^56 + 2^16
663 static void felem_neg(felem out
, const felem in
)
666 felem_diff_128_64(tmp
, in
);
667 felem_reduce(out
, tmp
);
671 * Zero-check: returns 1 if input is 0, and 0 otherwise. We know that field
672 * elements are reduced to in < 2^225, so we only need to check three cases:
673 * 0, 2^224 - 2^96 + 1, and 2^225 - 2^97 + 2
675 static limb
felem_is_zero(const felem in
)
677 limb zero
, two224m96p1
, two225m97p2
;
679 zero
= in
[0] | in
[1] | in
[2] | in
[3];
680 zero
= (((int64_t) (zero
) - 1) >> 63) & 1;
681 two224m96p1
= (in
[0] ^ 1) | (in
[1] ^ 0x00ffff0000000000)
682 | (in
[2] ^ 0x00ffffffffffffff) | (in
[3] ^ 0x00ffffffffffffff);
683 two224m96p1
= (((int64_t) (two224m96p1
) - 1) >> 63) & 1;
684 two225m97p2
= (in
[0] ^ 2) | (in
[1] ^ 0x00fffe0000000000)
685 | (in
[2] ^ 0x00ffffffffffffff) | (in
[3] ^ 0x01ffffffffffffff);
686 two225m97p2
= (((int64_t) (two225m97p2
) - 1) >> 63) & 1;
687 return (zero
| two224m96p1
| two225m97p2
);
690 static int felem_is_zero_int(const void *in
)
692 return (int)(felem_is_zero(in
) & ((limb
) 1));
695 /* Invert a field element */
696 /* Computation chain copied from djb's code */
697 static void felem_inv(felem out
, const felem in
)
699 felem ftmp
, ftmp2
, ftmp3
, ftmp4
;
703 felem_square(tmp
, in
);
704 felem_reduce(ftmp
, tmp
); /* 2 */
705 felem_mul(tmp
, in
, ftmp
);
706 felem_reduce(ftmp
, tmp
); /* 2^2 - 1 */
707 felem_square(tmp
, ftmp
);
708 felem_reduce(ftmp
, tmp
); /* 2^3 - 2 */
709 felem_mul(tmp
, in
, ftmp
);
710 felem_reduce(ftmp
, tmp
); /* 2^3 - 1 */
711 felem_square(tmp
, ftmp
);
712 felem_reduce(ftmp2
, tmp
); /* 2^4 - 2 */
713 felem_square(tmp
, ftmp2
);
714 felem_reduce(ftmp2
, tmp
); /* 2^5 - 4 */
715 felem_square(tmp
, ftmp2
);
716 felem_reduce(ftmp2
, tmp
); /* 2^6 - 8 */
717 felem_mul(tmp
, ftmp2
, ftmp
);
718 felem_reduce(ftmp
, tmp
); /* 2^6 - 1 */
719 felem_square(tmp
, ftmp
);
720 felem_reduce(ftmp2
, tmp
); /* 2^7 - 2 */
721 for (i
= 0; i
< 5; ++i
) { /* 2^12 - 2^6 */
722 felem_square(tmp
, ftmp2
);
723 felem_reduce(ftmp2
, tmp
);
725 felem_mul(tmp
, ftmp2
, ftmp
);
726 felem_reduce(ftmp2
, tmp
); /* 2^12 - 1 */
727 felem_square(tmp
, ftmp2
);
728 felem_reduce(ftmp3
, tmp
); /* 2^13 - 2 */
729 for (i
= 0; i
< 11; ++i
) { /* 2^24 - 2^12 */
730 felem_square(tmp
, ftmp3
);
731 felem_reduce(ftmp3
, tmp
);
733 felem_mul(tmp
, ftmp3
, ftmp2
);
734 felem_reduce(ftmp2
, tmp
); /* 2^24 - 1 */
735 felem_square(tmp
, ftmp2
);
736 felem_reduce(ftmp3
, tmp
); /* 2^25 - 2 */
737 for (i
= 0; i
< 23; ++i
) { /* 2^48 - 2^24 */
738 felem_square(tmp
, ftmp3
);
739 felem_reduce(ftmp3
, tmp
);
741 felem_mul(tmp
, ftmp3
, ftmp2
);
742 felem_reduce(ftmp3
, tmp
); /* 2^48 - 1 */
743 felem_square(tmp
, ftmp3
);
744 felem_reduce(ftmp4
, tmp
); /* 2^49 - 2 */
745 for (i
= 0; i
< 47; ++i
) { /* 2^96 - 2^48 */
746 felem_square(tmp
, ftmp4
);
747 felem_reduce(ftmp4
, tmp
);
749 felem_mul(tmp
, ftmp3
, ftmp4
);
750 felem_reduce(ftmp3
, tmp
); /* 2^96 - 1 */
751 felem_square(tmp
, ftmp3
);
752 felem_reduce(ftmp4
, tmp
); /* 2^97 - 2 */
753 for (i
= 0; i
< 23; ++i
) { /* 2^120 - 2^24 */
754 felem_square(tmp
, ftmp4
);
755 felem_reduce(ftmp4
, tmp
);
757 felem_mul(tmp
, ftmp2
, ftmp4
);
758 felem_reduce(ftmp2
, tmp
); /* 2^120 - 1 */
759 for (i
= 0; i
< 6; ++i
) { /* 2^126 - 2^6 */
760 felem_square(tmp
, ftmp2
);
761 felem_reduce(ftmp2
, tmp
);
763 felem_mul(tmp
, ftmp2
, ftmp
);
764 felem_reduce(ftmp
, tmp
); /* 2^126 - 1 */
765 felem_square(tmp
, ftmp
);
766 felem_reduce(ftmp
, tmp
); /* 2^127 - 2 */
767 felem_mul(tmp
, ftmp
, in
);
768 felem_reduce(ftmp
, tmp
); /* 2^127 - 1 */
769 for (i
= 0; i
< 97; ++i
) { /* 2^224 - 2^97 */
770 felem_square(tmp
, ftmp
);
771 felem_reduce(ftmp
, tmp
);
773 felem_mul(tmp
, ftmp
, ftmp3
);
774 felem_reduce(out
, tmp
); /* 2^224 - 2^96 - 1 */
778 * Copy in constant time: if icopy == 1, copy in to out, if icopy == 0, copy
781 static void copy_conditional(felem out
, const felem in
, limb icopy
)
785 * icopy is a (64-bit) 0 or 1, so copy is either all-zero or all-one
787 const limb copy
= -icopy
;
788 for (i
= 0; i
< 4; ++i
) {
789 const limb tmp
= copy
& (in
[i
] ^ out
[i
]);
794 /******************************************************************************/
796 * ELLIPTIC CURVE POINT OPERATIONS
798 * Points are represented in Jacobian projective coordinates:
799 * (X, Y, Z) corresponds to the affine point (X/Z^2, Y/Z^3),
800 * or to the point at infinity if Z == 0.
805 * Double an elliptic curve point:
806 * (X', Y', Z') = 2 * (X, Y, Z), where
807 * X' = (3 * (X - Z^2) * (X + Z^2))^2 - 8 * X * Y^2
808 * Y' = 3 * (X - Z^2) * (X + Z^2) * (4 * X * Y^2 - X') - 8 * Y^4
809 * Z' = (Y + Z)^2 - Y^2 - Z^2 = 2 * Y * Z
810 * Outputs can equal corresponding inputs, i.e., x_out == x_in is allowed,
811 * while x_out == y_in is not (maybe this works, but it's not tested).
814 point_double(felem x_out
, felem y_out
, felem z_out
,
815 const felem x_in
, const felem y_in
, const felem z_in
)
818 felem delta
, gamma
, beta
, alpha
, ftmp
, ftmp2
;
820 felem_assign(ftmp
, x_in
);
821 felem_assign(ftmp2
, x_in
);
824 felem_square(tmp
, z_in
);
825 felem_reduce(delta
, tmp
);
828 felem_square(tmp
, y_in
);
829 felem_reduce(gamma
, tmp
);
832 felem_mul(tmp
, x_in
, gamma
);
833 felem_reduce(beta
, tmp
);
835 /* alpha = 3*(x-delta)*(x+delta) */
836 felem_diff(ftmp
, delta
);
837 /* ftmp[i] < 2^57 + 2^58 + 2 < 2^59 */
838 felem_sum(ftmp2
, delta
);
839 /* ftmp2[i] < 2^57 + 2^57 = 2^58 */
840 felem_scalar(ftmp2
, 3);
841 /* ftmp2[i] < 3 * 2^58 < 2^60 */
842 felem_mul(tmp
, ftmp
, ftmp2
);
843 /* tmp[i] < 2^60 * 2^59 * 4 = 2^121 */
844 felem_reduce(alpha
, tmp
);
846 /* x' = alpha^2 - 8*beta */
847 felem_square(tmp
, alpha
);
848 /* tmp[i] < 4 * 2^57 * 2^57 = 2^116 */
849 felem_assign(ftmp
, beta
);
850 felem_scalar(ftmp
, 8);
851 /* ftmp[i] < 8 * 2^57 = 2^60 */
852 felem_diff_128_64(tmp
, ftmp
);
853 /* tmp[i] < 2^116 + 2^64 + 8 < 2^117 */
854 felem_reduce(x_out
, tmp
);
856 /* z' = (y + z)^2 - gamma - delta */
857 felem_sum(delta
, gamma
);
858 /* delta[i] < 2^57 + 2^57 = 2^58 */
859 felem_assign(ftmp
, y_in
);
860 felem_sum(ftmp
, z_in
);
861 /* ftmp[i] < 2^57 + 2^57 = 2^58 */
862 felem_square(tmp
, ftmp
);
863 /* tmp[i] < 4 * 2^58 * 2^58 = 2^118 */
864 felem_diff_128_64(tmp
, delta
);
865 /* tmp[i] < 2^118 + 2^64 + 8 < 2^119 */
866 felem_reduce(z_out
, tmp
);
868 /* y' = alpha*(4*beta - x') - 8*gamma^2 */
869 felem_scalar(beta
, 4);
870 /* beta[i] < 4 * 2^57 = 2^59 */
871 felem_diff(beta
, x_out
);
872 /* beta[i] < 2^59 + 2^58 + 2 < 2^60 */
873 felem_mul(tmp
, alpha
, beta
);
874 /* tmp[i] < 4 * 2^57 * 2^60 = 2^119 */
875 felem_square(tmp2
, gamma
);
876 /* tmp2[i] < 4 * 2^57 * 2^57 = 2^116 */
877 widefelem_scalar(tmp2
, 8);
878 /* tmp2[i] < 8 * 2^116 = 2^119 */
879 widefelem_diff(tmp
, tmp2
);
880 /* tmp[i] < 2^119 + 2^120 < 2^121 */
881 felem_reduce(y_out
, tmp
);
885 * Add two elliptic curve points:
886 * (X_1, Y_1, Z_1) + (X_2, Y_2, Z_2) = (X_3, Y_3, Z_3), where
887 * X_3 = (Z_1^3 * Y_2 - Z_2^3 * Y_1)^2 - (Z_1^2 * X_2 - Z_2^2 * X_1)^3 -
888 * 2 * Z_2^2 * X_1 * (Z_1^2 * X_2 - Z_2^2 * X_1)^2
889 * Y_3 = (Z_1^3 * Y_2 - Z_2^3 * Y_1) * (Z_2^2 * X_1 * (Z_1^2 * X_2 - Z_2^2 * X_1)^2 - X_3) -
890 * Z_2^3 * Y_1 * (Z_1^2 * X_2 - Z_2^2 * X_1)^3
891 * Z_3 = (Z_1^2 * X_2 - Z_2^2 * X_1) * (Z_1 * Z_2)
893 * This runs faster if 'mixed' is set, which requires Z_2 = 1 or Z_2 = 0.
897 * This function is not entirely constant-time: it includes a branch for
898 * checking whether the two input points are equal, (while not equal to the
899 * point at infinity). This case never happens during single point
900 * multiplication, so there is no timing leak for ECDH or ECDSA signing.
902 static void point_add(felem x3
, felem y3
, felem z3
,
903 const felem x1
, const felem y1
, const felem z1
,
904 const int mixed
, const felem x2
, const felem y2
,
907 felem ftmp
, ftmp2
, ftmp3
, ftmp4
, ftmp5
, x_out
, y_out
, z_out
;
909 limb z1_is_zero
, z2_is_zero
, x_equal
, y_equal
;
914 felem_square(tmp
, z2
);
915 felem_reduce(ftmp2
, tmp
);
918 felem_mul(tmp
, ftmp2
, z2
);
919 felem_reduce(ftmp4
, tmp
);
921 /* ftmp4 = z2^3*y1 */
922 felem_mul(tmp2
, ftmp4
, y1
);
923 felem_reduce(ftmp4
, tmp2
);
925 /* ftmp2 = z2^2*x1 */
926 felem_mul(tmp2
, ftmp2
, x1
);
927 felem_reduce(ftmp2
, tmp2
);
930 * We'll assume z2 = 1 (special case z2 = 0 is handled later)
933 /* ftmp4 = z2^3*y1 */
934 felem_assign(ftmp4
, y1
);
936 /* ftmp2 = z2^2*x1 */
937 felem_assign(ftmp2
, x1
);
941 felem_square(tmp
, z1
);
942 felem_reduce(ftmp
, tmp
);
945 felem_mul(tmp
, ftmp
, z1
);
946 felem_reduce(ftmp3
, tmp
);
949 felem_mul(tmp
, ftmp3
, y2
);
950 /* tmp[i] < 4 * 2^57 * 2^57 = 2^116 */
952 /* ftmp3 = z1^3*y2 - z2^3*y1 */
953 felem_diff_128_64(tmp
, ftmp4
);
954 /* tmp[i] < 2^116 + 2^64 + 8 < 2^117 */
955 felem_reduce(ftmp3
, tmp
);
958 felem_mul(tmp
, ftmp
, x2
);
959 /* tmp[i] < 4 * 2^57 * 2^57 = 2^116 */
961 /* ftmp = z1^2*x2 - z2^2*x1 */
962 felem_diff_128_64(tmp
, ftmp2
);
963 /* tmp[i] < 2^116 + 2^64 + 8 < 2^117 */
964 felem_reduce(ftmp
, tmp
);
967 * The formulae are incorrect if the points are equal, in affine coordinates
968 * (X_1, Y_1) == (X_2, Y_2), so we check for this and do doubling if this
971 * We use bitwise operations to avoid potential side-channels introduced by
972 * the short-circuiting behaviour of boolean operators.
974 x_equal
= felem_is_zero(ftmp
);
975 y_equal
= felem_is_zero(ftmp3
);
977 * The special case of either point being the point at infinity (z1 and/or
978 * z2 are zero), is handled separately later on in this function, so we
979 * avoid jumping to point_double here in those special cases.
981 z1_is_zero
= felem_is_zero(z1
);
982 z2_is_zero
= felem_is_zero(z2
);
985 * Compared to `ecp_nistp256.c` and `ecp_nistp521.c`, in this
986 * specific implementation `felem_is_zero()` returns truth as `0x1`
987 * (rather than `0xff..ff`).
989 * This implies that `~true` in this implementation becomes
990 * `0xff..fe` (rather than `0x0`): for this reason, to be used in
991 * the if expression, we mask out only the last bit in the next
994 points_equal
= (x_equal
& y_equal
& (~z1_is_zero
) & (~z2_is_zero
)) & 1;
998 * This is obviously not constant-time but, as mentioned before, this
999 * case never happens during single point multiplication, so there is no
1000 * timing leak for ECDH or ECDSA signing.
1002 point_double(x3
, y3
, z3
, x1
, y1
, z1
);
1008 felem_mul(tmp
, z1
, z2
);
1009 felem_reduce(ftmp5
, tmp
);
1011 /* special case z2 = 0 is handled later */
1012 felem_assign(ftmp5
, z1
);
1015 /* z_out = (z1^2*x2 - z2^2*x1)*(z1*z2) */
1016 felem_mul(tmp
, ftmp
, ftmp5
);
1017 felem_reduce(z_out
, tmp
);
1019 /* ftmp = (z1^2*x2 - z2^2*x1)^2 */
1020 felem_assign(ftmp5
, ftmp
);
1021 felem_square(tmp
, ftmp
);
1022 felem_reduce(ftmp
, tmp
);
1024 /* ftmp5 = (z1^2*x2 - z2^2*x1)^3 */
1025 felem_mul(tmp
, ftmp
, ftmp5
);
1026 felem_reduce(ftmp5
, tmp
);
1028 /* ftmp2 = z2^2*x1*(z1^2*x2 - z2^2*x1)^2 */
1029 felem_mul(tmp
, ftmp2
, ftmp
);
1030 felem_reduce(ftmp2
, tmp
);
1032 /* tmp = z2^3*y1*(z1^2*x2 - z2^2*x1)^3 */
1033 felem_mul(tmp
, ftmp4
, ftmp5
);
1034 /* tmp[i] < 4 * 2^57 * 2^57 = 2^116 */
1036 /* tmp2 = (z1^3*y2 - z2^3*y1)^2 */
1037 felem_square(tmp2
, ftmp3
);
1038 /* tmp2[i] < 4 * 2^57 * 2^57 < 2^116 */
1040 /* tmp2 = (z1^3*y2 - z2^3*y1)^2 - (z1^2*x2 - z2^2*x1)^3 */
1041 felem_diff_128_64(tmp2
, ftmp5
);
1042 /* tmp2[i] < 2^116 + 2^64 + 8 < 2^117 */
1044 /* ftmp5 = 2*z2^2*x1*(z1^2*x2 - z2^2*x1)^2 */
1045 felem_assign(ftmp5
, ftmp2
);
1046 felem_scalar(ftmp5
, 2);
1047 /* ftmp5[i] < 2 * 2^57 = 2^58 */
1050 * x_out = (z1^3*y2 - z2^3*y1)^2 - (z1^2*x2 - z2^2*x1)^3 -
1051 * 2*z2^2*x1*(z1^2*x2 - z2^2*x1)^2
1053 felem_diff_128_64(tmp2
, ftmp5
);
1054 /* tmp2[i] < 2^117 + 2^64 + 8 < 2^118 */
1055 felem_reduce(x_out
, tmp2
);
1057 /* ftmp2 = z2^2*x1*(z1^2*x2 - z2^2*x1)^2 - x_out */
1058 felem_diff(ftmp2
, x_out
);
1059 /* ftmp2[i] < 2^57 + 2^58 + 2 < 2^59 */
1062 * tmp2 = (z1^3*y2 - z2^3*y1)*(z2^2*x1*(z1^2*x2 - z2^2*x1)^2 - x_out)
1064 felem_mul(tmp2
, ftmp3
, ftmp2
);
1065 /* tmp2[i] < 4 * 2^57 * 2^59 = 2^118 */
1068 * y_out = (z1^3*y2 - z2^3*y1)*(z2^2*x1*(z1^2*x2 - z2^2*x1)^2 - x_out) -
1069 * z2^3*y1*(z1^2*x2 - z2^2*x1)^3
1071 widefelem_diff(tmp2
, tmp
);
1072 /* tmp2[i] < 2^118 + 2^120 < 2^121 */
1073 felem_reduce(y_out
, tmp2
);
1076 * the result (x_out, y_out, z_out) is incorrect if one of the inputs is
1077 * the point at infinity, so we need to check for this separately
1081 * if point 1 is at infinity, copy point 2 to output, and vice versa
1083 copy_conditional(x_out
, x2
, z1_is_zero
);
1084 copy_conditional(x_out
, x1
, z2_is_zero
);
1085 copy_conditional(y_out
, y2
, z1_is_zero
);
1086 copy_conditional(y_out
, y1
, z2_is_zero
);
1087 copy_conditional(z_out
, z2
, z1_is_zero
);
1088 copy_conditional(z_out
, z1
, z2_is_zero
);
1089 felem_assign(x3
, x_out
);
1090 felem_assign(y3
, y_out
);
1091 felem_assign(z3
, z_out
);
1095 * select_point selects the |idx|th point from a precomputation table and
1097 * The pre_comp array argument should be size of |size| argument
1099 static void select_point(const u64 idx
, unsigned int size
,
1100 const felem pre_comp
[][3], felem out
[3])
1103 limb
*outlimbs
= &out
[0][0];
1105 memset(out
, 0, sizeof(*out
) * 3);
1106 for (i
= 0; i
< size
; i
++) {
1107 const limb
*inlimbs
= &pre_comp
[i
][0][0];
1114 for (j
= 0; j
< 4 * 3; j
++)
1115 outlimbs
[j
] |= inlimbs
[j
] & mask
;
1119 /* get_bit returns the |i|th bit in |in| */
1120 static char get_bit(const felem_bytearray in
, unsigned i
)
1124 return (in
[i
>> 3] >> (i
& 7)) & 1;
1128 * Interleaved point multiplication using precomputed point multiples: The
1129 * small point multiples 0*P, 1*P, ..., 16*P are in pre_comp[], the scalars
1130 * in scalars[]. If g_scalar is non-NULL, we also add this multiple of the
1131 * generator, using certain (large) precomputed multiples in g_pre_comp.
1132 * Output point (X, Y, Z) is stored in x_out, y_out, z_out
1134 static void batch_mul(felem x_out
, felem y_out
, felem z_out
,
1135 const felem_bytearray scalars
[],
1136 const unsigned num_points
, const u8
*g_scalar
,
1137 const int mixed
, const felem pre_comp
[][17][3],
1138 const felem g_pre_comp
[2][16][3])
1142 unsigned gen_mul
= (g_scalar
!= NULL
);
1143 felem nq
[3], tmp
[4];
1147 /* set nq to the point at infinity */
1148 memset(nq
, 0, sizeof(nq
));
1151 * Loop over all scalars msb-to-lsb, interleaving additions of multiples
1152 * of the generator (two in each of the last 28 rounds) and additions of
1153 * other points multiples (every 5th round).
1155 skip
= 1; /* save two point operations in the first
1157 for (i
= (num_points
? 220 : 27); i
>= 0; --i
) {
1160 point_double(nq
[0], nq
[1], nq
[2], nq
[0], nq
[1], nq
[2]);
1162 /* add multiples of the generator */
1163 if (gen_mul
&& (i
<= 27)) {
1164 /* first, look 28 bits upwards */
1165 bits
= get_bit(g_scalar
, i
+ 196) << 3;
1166 bits
|= get_bit(g_scalar
, i
+ 140) << 2;
1167 bits
|= get_bit(g_scalar
, i
+ 84) << 1;
1168 bits
|= get_bit(g_scalar
, i
+ 28);
1169 /* select the point to add, in constant time */
1170 select_point(bits
, 16, g_pre_comp
[1], tmp
);
1173 /* value 1 below is argument for "mixed" */
1174 point_add(nq
[0], nq
[1], nq
[2],
1175 nq
[0], nq
[1], nq
[2], 1, tmp
[0], tmp
[1], tmp
[2]);
1177 memcpy(nq
, tmp
, 3 * sizeof(felem
));
1181 /* second, look at the current position */
1182 bits
= get_bit(g_scalar
, i
+ 168) << 3;
1183 bits
|= get_bit(g_scalar
, i
+ 112) << 2;
1184 bits
|= get_bit(g_scalar
, i
+ 56) << 1;
1185 bits
|= get_bit(g_scalar
, i
);
1186 /* select the point to add, in constant time */
1187 select_point(bits
, 16, g_pre_comp
[0], tmp
);
1188 point_add(nq
[0], nq
[1], nq
[2],
1189 nq
[0], nq
[1], nq
[2],
1190 1 /* mixed */ , tmp
[0], tmp
[1], tmp
[2]);
1193 /* do other additions every 5 doublings */
1194 if (num_points
&& (i
% 5 == 0)) {
1195 /* loop over all scalars */
1196 for (num
= 0; num
< num_points
; ++num
) {
1197 bits
= get_bit(scalars
[num
], i
+ 4) << 5;
1198 bits
|= get_bit(scalars
[num
], i
+ 3) << 4;
1199 bits
|= get_bit(scalars
[num
], i
+ 2) << 3;
1200 bits
|= get_bit(scalars
[num
], i
+ 1) << 2;
1201 bits
|= get_bit(scalars
[num
], i
) << 1;
1202 bits
|= get_bit(scalars
[num
], i
- 1);
1203 ec_GFp_nistp_recode_scalar_bits(&sign
, &digit
, bits
);
1205 /* select the point to add or subtract */
1206 select_point(digit
, 17, pre_comp
[num
], tmp
);
1207 felem_neg(tmp
[3], tmp
[1]); /* (X, -Y, Z) is the negative
1209 copy_conditional(tmp
[1], tmp
[3], sign
);
1212 point_add(nq
[0], nq
[1], nq
[2],
1213 nq
[0], nq
[1], nq
[2],
1214 mixed
, tmp
[0], tmp
[1], tmp
[2]);
1216 memcpy(nq
, tmp
, 3 * sizeof(felem
));
1222 felem_assign(x_out
, nq
[0]);
1223 felem_assign(y_out
, nq
[1]);
1224 felem_assign(z_out
, nq
[2]);
1227 /******************************************************************************/
1229 * FUNCTIONS TO MANAGE PRECOMPUTATION
1232 static NISTP224_PRE_COMP
*nistp224_pre_comp_new(void)
1234 NISTP224_PRE_COMP
*ret
= OPENSSL_zalloc(sizeof(*ret
));
1237 ECerr(EC_F_NISTP224_PRE_COMP_NEW
, ERR_R_MALLOC_FAILURE
);
1241 ret
->references
= 1;
1243 ret
->lock
= CRYPTO_THREAD_lock_new();
1244 if (ret
->lock
== NULL
) {
1245 ECerr(EC_F_NISTP224_PRE_COMP_NEW
, ERR_R_MALLOC_FAILURE
);
1252 NISTP224_PRE_COMP
*EC_nistp224_pre_comp_dup(NISTP224_PRE_COMP
*p
)
1256 CRYPTO_UP_REF(&p
->references
, &i
, p
->lock
);
1260 void EC_nistp224_pre_comp_free(NISTP224_PRE_COMP
*p
)
1267 CRYPTO_DOWN_REF(&p
->references
, &i
, p
->lock
);
1268 REF_PRINT_COUNT("EC_nistp224", x
);
1271 REF_ASSERT_ISNT(i
< 0);
1273 CRYPTO_THREAD_lock_free(p
->lock
);
1277 /******************************************************************************/
1279 * OPENSSL EC_METHOD FUNCTIONS
1282 int ec_GFp_nistp224_group_init(EC_GROUP
*group
)
1285 ret
= ec_GFp_simple_group_init(group
);
1286 group
->a_is_minus3
= 1;
1290 int ec_GFp_nistp224_group_set_curve(EC_GROUP
*group
, const BIGNUM
*p
,
1291 const BIGNUM
*a
, const BIGNUM
*b
,
1295 BN_CTX
*new_ctx
= NULL
;
1296 BIGNUM
*curve_p
, *curve_a
, *curve_b
;
1299 if ((ctx
= new_ctx
= BN_CTX_new()) == NULL
)
1302 curve_p
= BN_CTX_get(ctx
);
1303 curve_a
= BN_CTX_get(ctx
);
1304 curve_b
= BN_CTX_get(ctx
);
1305 if (curve_b
== NULL
)
1307 BN_bin2bn(nistp224_curve_params
[0], sizeof(felem_bytearray
), curve_p
);
1308 BN_bin2bn(nistp224_curve_params
[1], sizeof(felem_bytearray
), curve_a
);
1309 BN_bin2bn(nistp224_curve_params
[2], sizeof(felem_bytearray
), curve_b
);
1310 if ((BN_cmp(curve_p
, p
)) || (BN_cmp(curve_a
, a
)) || (BN_cmp(curve_b
, b
))) {
1311 ECerr(EC_F_EC_GFP_NISTP224_GROUP_SET_CURVE
,
1312 EC_R_WRONG_CURVE_PARAMETERS
);
1315 group
->field_mod_func
= BN_nist_mod_224
;
1316 ret
= ec_GFp_simple_group_set_curve(group
, p
, a
, b
, ctx
);
1319 BN_CTX_free(new_ctx
);
1324 * Takes the Jacobian coordinates (X, Y, Z) of a point and returns (X', Y') =
1327 int ec_GFp_nistp224_point_get_affine_coordinates(const EC_GROUP
*group
,
1328 const EC_POINT
*point
,
1329 BIGNUM
*x
, BIGNUM
*y
,
1332 felem z1
, z2
, x_in
, y_in
, x_out
, y_out
;
1335 if (EC_POINT_is_at_infinity(group
, point
)) {
1336 ECerr(EC_F_EC_GFP_NISTP224_POINT_GET_AFFINE_COORDINATES
,
1337 EC_R_POINT_AT_INFINITY
);
1340 if ((!BN_to_felem(x_in
, point
->X
)) || (!BN_to_felem(y_in
, point
->Y
)) ||
1341 (!BN_to_felem(z1
, point
->Z
)))
1344 felem_square(tmp
, z2
);
1345 felem_reduce(z1
, tmp
);
1346 felem_mul(tmp
, x_in
, z1
);
1347 felem_reduce(x_in
, tmp
);
1348 felem_contract(x_out
, x_in
);
1350 if (!felem_to_BN(x
, x_out
)) {
1351 ECerr(EC_F_EC_GFP_NISTP224_POINT_GET_AFFINE_COORDINATES
,
1356 felem_mul(tmp
, z1
, z2
);
1357 felem_reduce(z1
, tmp
);
1358 felem_mul(tmp
, y_in
, z1
);
1359 felem_reduce(y_in
, tmp
);
1360 felem_contract(y_out
, y_in
);
1362 if (!felem_to_BN(y
, y_out
)) {
1363 ECerr(EC_F_EC_GFP_NISTP224_POINT_GET_AFFINE_COORDINATES
,
1371 static void make_points_affine(size_t num
, felem points
[ /* num */ ][3],
1372 felem tmp_felems
[ /* num+1 */ ])
1375 * Runs in constant time, unless an input is the point at infinity (which
1376 * normally shouldn't happen).
1378 ec_GFp_nistp_points_make_affine_internal(num
,
1382 (void (*)(void *))felem_one
,
1384 (void (*)(void *, const void *))
1386 (void (*)(void *, const void *))
1387 felem_square_reduce
, (void (*)
1394 (void (*)(void *, const void *))
1396 (void (*)(void *, const void *))
1401 * Computes scalar*generator + \sum scalars[i]*points[i], ignoring NULL
1402 * values Result is stored in r (r can equal one of the inputs).
1404 int ec_GFp_nistp224_points_mul(const EC_GROUP
*group
, EC_POINT
*r
,
1405 const BIGNUM
*scalar
, size_t num
,
1406 const EC_POINT
*points
[],
1407 const BIGNUM
*scalars
[], BN_CTX
*ctx
)
1413 BIGNUM
*x
, *y
, *z
, *tmp_scalar
;
1414 felem_bytearray g_secret
;
1415 felem_bytearray
*secrets
= NULL
;
1416 felem (*pre_comp
)[17][3] = NULL
;
1417 felem
*tmp_felems
= NULL
;
1419 int have_pre_comp
= 0;
1420 size_t num_points
= num
;
1421 felem x_in
, y_in
, z_in
, x_out
, y_out
, z_out
;
1422 NISTP224_PRE_COMP
*pre
= NULL
;
1423 const felem(*g_pre_comp
)[16][3] = NULL
;
1424 EC_POINT
*generator
= NULL
;
1425 const EC_POINT
*p
= NULL
;
1426 const BIGNUM
*p_scalar
= NULL
;
1429 x
= BN_CTX_get(ctx
);
1430 y
= BN_CTX_get(ctx
);
1431 z
= BN_CTX_get(ctx
);
1432 tmp_scalar
= BN_CTX_get(ctx
);
1433 if (tmp_scalar
== NULL
)
1436 if (scalar
!= NULL
) {
1437 pre
= group
->pre_comp
.nistp224
;
1439 /* we have precomputation, try to use it */
1440 g_pre_comp
= (const felem(*)[16][3])pre
->g_pre_comp
;
1442 /* try to use the standard precomputation */
1443 g_pre_comp
= &gmul
[0];
1444 generator
= EC_POINT_new(group
);
1445 if (generator
== NULL
)
1447 /* get the generator from precomputation */
1448 if (!felem_to_BN(x
, g_pre_comp
[0][1][0]) ||
1449 !felem_to_BN(y
, g_pre_comp
[0][1][1]) ||
1450 !felem_to_BN(z
, g_pre_comp
[0][1][2])) {
1451 ECerr(EC_F_EC_GFP_NISTP224_POINTS_MUL
, ERR_R_BN_LIB
);
1454 if (!EC_POINT_set_Jprojective_coordinates_GFp(group
,
1458 if (0 == EC_POINT_cmp(group
, generator
, group
->generator
, ctx
))
1459 /* precomputation matches generator */
1463 * we don't have valid precomputation: treat the generator as a
1466 num_points
= num_points
+ 1;
1469 if (num_points
> 0) {
1470 if (num_points
>= 3) {
1472 * unless we precompute multiples for just one or two points,
1473 * converting those into affine form is time well spent
1477 secrets
= OPENSSL_zalloc(sizeof(*secrets
) * num_points
);
1478 pre_comp
= OPENSSL_zalloc(sizeof(*pre_comp
) * num_points
);
1481 OPENSSL_malloc(sizeof(felem
) * (num_points
* 17 + 1));
1482 if ((secrets
== NULL
) || (pre_comp
== NULL
)
1483 || (mixed
&& (tmp_felems
== NULL
))) {
1484 ECerr(EC_F_EC_GFP_NISTP224_POINTS_MUL
, ERR_R_MALLOC_FAILURE
);
1489 * we treat NULL scalars as 0, and NULL points as points at infinity,
1490 * i.e., they contribute nothing to the linear combination
1492 for (i
= 0; i
< num_points
; ++i
) {
1495 p
= EC_GROUP_get0_generator(group
);
1498 /* the i^th point */
1500 p_scalar
= scalars
[i
];
1502 if ((p_scalar
!= NULL
) && (p
!= NULL
)) {
1503 /* reduce scalar to 0 <= scalar < 2^224 */
1504 if ((BN_num_bits(p_scalar
) > 224)
1505 || (BN_is_negative(p_scalar
))) {
1507 * this is an unusual input, and we don't guarantee
1510 if (!BN_nnmod(tmp_scalar
, p_scalar
, group
->order
, ctx
)) {
1511 ECerr(EC_F_EC_GFP_NISTP224_POINTS_MUL
, ERR_R_BN_LIB
);
1514 num_bytes
= BN_bn2lebinpad(tmp_scalar
,
1515 secrets
[i
], sizeof(secrets
[i
]));
1517 num_bytes
= BN_bn2lebinpad(p_scalar
,
1518 secrets
[i
], sizeof(secrets
[i
]));
1520 if (num_bytes
< 0) {
1521 ECerr(EC_F_EC_GFP_NISTP224_POINTS_MUL
, ERR_R_BN_LIB
);
1524 /* precompute multiples */
1525 if ((!BN_to_felem(x_out
, p
->X
)) ||
1526 (!BN_to_felem(y_out
, p
->Y
)) ||
1527 (!BN_to_felem(z_out
, p
->Z
)))
1529 felem_assign(pre_comp
[i
][1][0], x_out
);
1530 felem_assign(pre_comp
[i
][1][1], y_out
);
1531 felem_assign(pre_comp
[i
][1][2], z_out
);
1532 for (j
= 2; j
<= 16; ++j
) {
1534 point_add(pre_comp
[i
][j
][0], pre_comp
[i
][j
][1],
1535 pre_comp
[i
][j
][2], pre_comp
[i
][1][0],
1536 pre_comp
[i
][1][1], pre_comp
[i
][1][2], 0,
1537 pre_comp
[i
][j
- 1][0],
1538 pre_comp
[i
][j
- 1][1],
1539 pre_comp
[i
][j
- 1][2]);
1541 point_double(pre_comp
[i
][j
][0], pre_comp
[i
][j
][1],
1542 pre_comp
[i
][j
][2], pre_comp
[i
][j
/ 2][0],
1543 pre_comp
[i
][j
/ 2][1],
1544 pre_comp
[i
][j
/ 2][2]);
1550 make_points_affine(num_points
* 17, pre_comp
[0], tmp_felems
);
1553 /* the scalar for the generator */
1554 if ((scalar
!= NULL
) && (have_pre_comp
)) {
1555 memset(g_secret
, 0, sizeof(g_secret
));
1556 /* reduce scalar to 0 <= scalar < 2^224 */
1557 if ((BN_num_bits(scalar
) > 224) || (BN_is_negative(scalar
))) {
1559 * this is an unusual input, and we don't guarantee
1562 if (!BN_nnmod(tmp_scalar
, scalar
, group
->order
, ctx
)) {
1563 ECerr(EC_F_EC_GFP_NISTP224_POINTS_MUL
, ERR_R_BN_LIB
);
1566 num_bytes
= BN_bn2lebinpad(tmp_scalar
, g_secret
, sizeof(g_secret
));
1568 num_bytes
= BN_bn2lebinpad(scalar
, g_secret
, sizeof(g_secret
));
1570 /* do the multiplication with generator precomputation */
1571 batch_mul(x_out
, y_out
, z_out
,
1572 (const felem_bytearray(*))secrets
, num_points
,
1574 mixed
, (const felem(*)[17][3])pre_comp
, g_pre_comp
);
1576 /* do the multiplication without generator precomputation */
1577 batch_mul(x_out
, y_out
, z_out
,
1578 (const felem_bytearray(*))secrets
, num_points
,
1579 NULL
, mixed
, (const felem(*)[17][3])pre_comp
, NULL
);
1581 /* reduce the output to its unique minimal representation */
1582 felem_contract(x_in
, x_out
);
1583 felem_contract(y_in
, y_out
);
1584 felem_contract(z_in
, z_out
);
1585 if ((!felem_to_BN(x
, x_in
)) || (!felem_to_BN(y
, y_in
)) ||
1586 (!felem_to_BN(z
, z_in
))) {
1587 ECerr(EC_F_EC_GFP_NISTP224_POINTS_MUL
, ERR_R_BN_LIB
);
1590 ret
= EC_POINT_set_Jprojective_coordinates_GFp(group
, r
, x
, y
, z
, ctx
);
1594 EC_POINT_free(generator
);
1595 OPENSSL_free(secrets
);
1596 OPENSSL_free(pre_comp
);
1597 OPENSSL_free(tmp_felems
);
1601 int ec_GFp_nistp224_precompute_mult(EC_GROUP
*group
, BN_CTX
*ctx
)
1604 NISTP224_PRE_COMP
*pre
= NULL
;
1606 BN_CTX
*new_ctx
= NULL
;
1608 EC_POINT
*generator
= NULL
;
1609 felem tmp_felems
[32];
1611 /* throw away old precomputation */
1612 EC_pre_comp_free(group
);
1614 if ((ctx
= new_ctx
= BN_CTX_new()) == NULL
)
1617 x
= BN_CTX_get(ctx
);
1618 y
= BN_CTX_get(ctx
);
1621 /* get the generator */
1622 if (group
->generator
== NULL
)
1624 generator
= EC_POINT_new(group
);
1625 if (generator
== NULL
)
1627 BN_bin2bn(nistp224_curve_params
[3], sizeof(felem_bytearray
), x
);
1628 BN_bin2bn(nistp224_curve_params
[4], sizeof(felem_bytearray
), y
);
1629 if (!EC_POINT_set_affine_coordinates(group
, generator
, x
, y
, ctx
))
1631 if ((pre
= nistp224_pre_comp_new()) == NULL
)
1634 * if the generator is the standard one, use built-in precomputation
1636 if (0 == EC_POINT_cmp(group
, generator
, group
->generator
, ctx
)) {
1637 memcpy(pre
->g_pre_comp
, gmul
, sizeof(pre
->g_pre_comp
));
1640 if ((!BN_to_felem(pre
->g_pre_comp
[0][1][0], group
->generator
->X
)) ||
1641 (!BN_to_felem(pre
->g_pre_comp
[0][1][1], group
->generator
->Y
)) ||
1642 (!BN_to_felem(pre
->g_pre_comp
[0][1][2], group
->generator
->Z
)))
1645 * compute 2^56*G, 2^112*G, 2^168*G for the first table, 2^28*G, 2^84*G,
1646 * 2^140*G, 2^196*G for the second one
1648 for (i
= 1; i
<= 8; i
<<= 1) {
1649 point_double(pre
->g_pre_comp
[1][i
][0], pre
->g_pre_comp
[1][i
][1],
1650 pre
->g_pre_comp
[1][i
][2], pre
->g_pre_comp
[0][i
][0],
1651 pre
->g_pre_comp
[0][i
][1], pre
->g_pre_comp
[0][i
][2]);
1652 for (j
= 0; j
< 27; ++j
) {
1653 point_double(pre
->g_pre_comp
[1][i
][0], pre
->g_pre_comp
[1][i
][1],
1654 pre
->g_pre_comp
[1][i
][2], pre
->g_pre_comp
[1][i
][0],
1655 pre
->g_pre_comp
[1][i
][1], pre
->g_pre_comp
[1][i
][2]);
1659 point_double(pre
->g_pre_comp
[0][2 * i
][0],
1660 pre
->g_pre_comp
[0][2 * i
][1],
1661 pre
->g_pre_comp
[0][2 * i
][2], pre
->g_pre_comp
[1][i
][0],
1662 pre
->g_pre_comp
[1][i
][1], pre
->g_pre_comp
[1][i
][2]);
1663 for (j
= 0; j
< 27; ++j
) {
1664 point_double(pre
->g_pre_comp
[0][2 * i
][0],
1665 pre
->g_pre_comp
[0][2 * i
][1],
1666 pre
->g_pre_comp
[0][2 * i
][2],
1667 pre
->g_pre_comp
[0][2 * i
][0],
1668 pre
->g_pre_comp
[0][2 * i
][1],
1669 pre
->g_pre_comp
[0][2 * i
][2]);
1672 for (i
= 0; i
< 2; i
++) {
1673 /* g_pre_comp[i][0] is the point at infinity */
1674 memset(pre
->g_pre_comp
[i
][0], 0, sizeof(pre
->g_pre_comp
[i
][0]));
1675 /* the remaining multiples */
1676 /* 2^56*G + 2^112*G resp. 2^84*G + 2^140*G */
1677 point_add(pre
->g_pre_comp
[i
][6][0], pre
->g_pre_comp
[i
][6][1],
1678 pre
->g_pre_comp
[i
][6][2], pre
->g_pre_comp
[i
][4][0],
1679 pre
->g_pre_comp
[i
][4][1], pre
->g_pre_comp
[i
][4][2],
1680 0, pre
->g_pre_comp
[i
][2][0], pre
->g_pre_comp
[i
][2][1],
1681 pre
->g_pre_comp
[i
][2][2]);
1682 /* 2^56*G + 2^168*G resp. 2^84*G + 2^196*G */
1683 point_add(pre
->g_pre_comp
[i
][10][0], pre
->g_pre_comp
[i
][10][1],
1684 pre
->g_pre_comp
[i
][10][2], pre
->g_pre_comp
[i
][8][0],
1685 pre
->g_pre_comp
[i
][8][1], pre
->g_pre_comp
[i
][8][2],
1686 0, pre
->g_pre_comp
[i
][2][0], pre
->g_pre_comp
[i
][2][1],
1687 pre
->g_pre_comp
[i
][2][2]);
1688 /* 2^112*G + 2^168*G resp. 2^140*G + 2^196*G */
1689 point_add(pre
->g_pre_comp
[i
][12][0], pre
->g_pre_comp
[i
][12][1],
1690 pre
->g_pre_comp
[i
][12][2], pre
->g_pre_comp
[i
][8][0],
1691 pre
->g_pre_comp
[i
][8][1], pre
->g_pre_comp
[i
][8][2],
1692 0, pre
->g_pre_comp
[i
][4][0], pre
->g_pre_comp
[i
][4][1],
1693 pre
->g_pre_comp
[i
][4][2]);
1695 * 2^56*G + 2^112*G + 2^168*G resp. 2^84*G + 2^140*G + 2^196*G
1697 point_add(pre
->g_pre_comp
[i
][14][0], pre
->g_pre_comp
[i
][14][1],
1698 pre
->g_pre_comp
[i
][14][2], pre
->g_pre_comp
[i
][12][0],
1699 pre
->g_pre_comp
[i
][12][1], pre
->g_pre_comp
[i
][12][2],
1700 0, pre
->g_pre_comp
[i
][2][0], pre
->g_pre_comp
[i
][2][1],
1701 pre
->g_pre_comp
[i
][2][2]);
1702 for (j
= 1; j
< 8; ++j
) {
1703 /* odd multiples: add G resp. 2^28*G */
1704 point_add(pre
->g_pre_comp
[i
][2 * j
+ 1][0],
1705 pre
->g_pre_comp
[i
][2 * j
+ 1][1],
1706 pre
->g_pre_comp
[i
][2 * j
+ 1][2],
1707 pre
->g_pre_comp
[i
][2 * j
][0],
1708 pre
->g_pre_comp
[i
][2 * j
][1],
1709 pre
->g_pre_comp
[i
][2 * j
][2], 0,
1710 pre
->g_pre_comp
[i
][1][0], pre
->g_pre_comp
[i
][1][1],
1711 pre
->g_pre_comp
[i
][1][2]);
1714 make_points_affine(31, &(pre
->g_pre_comp
[0][1]), tmp_felems
);
1717 SETPRECOMP(group
, nistp224
, pre
);
1722 EC_POINT_free(generator
);
1723 BN_CTX_free(new_ctx
);
1724 EC_nistp224_pre_comp_free(pre
);
1728 int ec_GFp_nistp224_have_precompute_mult(const EC_GROUP
*group
)
1730 return HAVEPRECOMP(group
, nistp224
);