3 This file is part of the ARM-Crypto-Lib.
4 Copyright (C) 2006-2012 Daniel Otte (daniel.otte@rub.de)
6 This program is free software: you can redistribute it and/or modify
7 it under the terms of the GNU General Public License as published by
8 the Free Software Foundation, either version 3 of the License, or
9 (at your option) any later version.
11 This program is distributed in the hope that it will be useful,
12 but WITHOUT ANY WARRANTY; without even the implied warranty of
13 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14 GNU General Public License for more details.
16 You should have received a copy of the GNU General Public License
17 along with this program. If not, see <http://www.gnu.org/licenses/>.
29 #include "bigint_io.h"
31 #include <avr/pgmspace.h>
36 #define bigint_print_hex(a)
43 * return POINT_AT_INFINITY
45 * M = 3*(X + Z^2)*(X - Z^2)
47 * Y' = M*(S - X') - 8*Y^4
51 * return (X', Y', Z', Z'^2, Z'^3)
54 uint8_t ecc_affine_to_chudnovsky_point(ecc_chudnovsky_point_t *dest,
55 const ecc_affine_point_t *src){
56 if(src->y.length_W == 0){
57 /* point at infinity */
58 bigint_set_zero(&dest->y);
61 bigint_copy(&dest->x, &src->x);
62 bigint_copy(&dest->y, &src->y);
63 dest->z1.wordv[0] = 1;
64 dest->z2.wordv[0] = 1;
65 dest->z3.wordv[0] = 1;
66 dest->z1.length_W = 1;
67 dest->z2.length_W = 1;
68 dest->z3.length_W = 1;
72 bigint_adjust(&dest->z1);
73 bigint_adjust(&dest->z2);
74 bigint_adjust(&dest->z3);
78 uint8_t ecc_chudnovsky_to_affine_point(ecc_affine_point_t *dest,
79 const ecc_chudnovsky_point_t *src,
80 const ecc_curve_sp_t *curve){
81 if(src->y.length_W == 0){
82 /* point at infinity */
83 bigint_set_zero(&dest->y);
86 bigint_word_t t_w[curve->p->length_W * 2];
87 bigint_word_t z1_w[curve->p->length_W * 2];
88 bigint_word_t z2_w[curve->p->length_W];
94 bigint_inverse(&z1, &src->z1, curve->p);
95 bigint_square(&t, &z1);
98 bigint_mul_u(&t, &src->x, &z2);
100 bigint_copy(&dest->x, &t);
101 bigint_mul_u(&t, &z1, &z2);
103 bigint_mul_u(&t, &t, &src->y);
105 bigint_copy(&dest->y, &t);
110 void ecc_chudnovsky_point_print(const ecc_chudnovsky_point_t *p){
111 if(p->y.length_W == 0){
112 printf_P(PSTR(" ECC point = point-at-infinity\n"));
115 printf_P(PSTR(" ECC point x = "));
116 bigint_print_hex(&p->x);
117 printf_P(PSTR("\n ECC point y = "));
118 bigint_print_hex(&p->y);
119 printf_P(PSTR("\n ECC point z1 = "));
120 bigint_print_hex(&p->z1);
121 printf_P(PSTR("\n ECC point z2 = "));
122 bigint_print_hex(&p->z2);
123 printf_P(PSTR("\n ECC point z3 = "));
124 bigint_print_hex(&p->z3);
128 uint8_t ecc_chudnovsky_point_double_sp(ecc_chudnovsky_point_t *dest,
129 const ecc_chudnovsky_point_t *a,
130 const ecc_curve_sp_t *curve){
131 if(a->y.length_W == 0){
132 /* point at infinity */
133 bigint_set_zero(&dest->y);
136 bigint_word_t s_w[curve->p->length_W * 2];
137 bigint_word_t m_w[curve->p->length_W * 2];
138 bigint_word_t t_w[curve->p->length_W * 2];
146 bigint_square(&t, &a->y);
148 bigint_mul_u(&s, &t, &a->x);
150 bigint_shiftleft(&s, 2);
154 bigint_sub_u(&t, &a->x, &a->z2);
155 // /**/curve->reduce_p(&t);
156 bigint_add_u(&m, &a->x, &a->z2);
157 // /**/curve->reduce_p(&m);
158 bigint_mul_s(&m, &m, &t);
161 bigint_shiftleft(&t, 1);
162 bigint_add_s(&m, &m, &t);
166 bigint_mul_u(&t, &a->z1, &a->y);
168 bigint_shiftleft(&t, 1);
170 bigint_copy(&dest->z1, &t);
173 bigint_square(&t, &m);
175 bigint_sub_s(&t, &t, &s);
176 bigint_sub_s(&t, &t, &s);
178 bigint_copy(&dest->x, &t);
181 bigint_sub_s(&s, &s, &t);
183 bigint_mul_s(&s, &s, &m);
185 bigint_square(&t, &a->y);
187 bigint_square(&t, &t);
189 bigint_shiftleft(&t, 3);
191 bigint_sub_s(&s, &s, &t);
193 bigint_copy(&dest->y, &s);
196 bigint_square(&t, &dest->z1);
198 bigint_copy(&dest->z2, &t);
201 bigint_mul_u(&t, &t, &dest->z1);
203 bigint_copy(&dest->z3, &t);
208 void ecc_chudnovsky_point_copy(ecc_chudnovsky_point_t *dest,
209 const ecc_chudnovsky_point_t *src){
210 bigint_copy(&dest->x, &src->x);
211 bigint_copy(&dest->y, &src->y);
212 bigint_copy(&dest->z1, &src->z1);
213 bigint_copy(&dest->z2, &src->z2);
214 bigint_copy(&dest->z3, &src->z3);
217 uint8_t ecc_chudnovsky_point_add_sp(ecc_chudnovsky_point_t *dest,
218 const ecc_chudnovsky_point_t *a,
219 const ecc_chudnovsky_point_t *b,
220 const ecc_curve_sp_t *curve){
221 if(a->y.length_W == 0){
222 ecc_chudnovsky_point_copy(dest, b);
225 if(b->y.length_W == 0){
226 ecc_chudnovsky_point_copy(dest, a);
229 bigint_word_t u1_w[curve->p->length_W * 2];
230 bigint_word_t u2_w[curve->p->length_W * 2];
231 bigint_word_t s1_w[curve->p->length_W * 2];
232 bigint_word_t s2_w[curve->p->length_W * 2];
233 bigint_t u1, u2, s1, s2;
241 bigint_mul_u(&u1, &a->x, &b->z2);
242 curve->reduce_p(&u1);
245 bigint_mul_u(&u2, &b->x, &a->z2);
246 curve->reduce_p(&u2);
249 bigint_mul_u(&s1, &a->y, &b->z3);
250 curve->reduce_p(&s1);
253 bigint_mul_u(&s2, &b->y, &a->z3);
254 curve->reduce_p(&s2);
256 if(bigint_cmp_u(&u1, &u2) == 0){
257 if(bigint_cmp_u(&s1, &s2)){
258 /* point at infinity */
259 bigint_set_zero(&dest->y);
262 /* a == b --> dest = 2*a */
263 ecc_chudnovsky_point_double_sp(dest, a, curve);
267 bigint_word_t h_w[curve->p->length_W * 2];
268 bigint_word_t r_w[curve->p->length_W * 2];
274 bigint_sub_s(&h, &u2, &u1);
275 /**/curve->reduce_p(&h);
278 bigint_sub_s(&r, &s2, &s1);
279 // /**/curve->reduce_p(&r);
282 bigint_mul_u(&s2, &a->z1, &b->z1);
283 curve->reduce_p(&s2);
284 bigint_mul_s(&s2, &s2, &h);
285 curve->reduce_p(&s2);
286 bigint_copy(&dest->z1, &s2);
288 /* compute u1*h^2 and h^3 */
289 bigint_square(&s2, &h);
290 curve->reduce_p(&s2);
291 bigint_mul_s(&h, &s2, &h);
293 bigint_mul_s(&u1, &s2, &u1);
294 curve->reduce_p(&u1);
297 bigint_square(&u2, &r);
298 curve->reduce_p(&u2);
299 bigint_sub_s(&u2, &u2, &h);
300 curve->reduce_p(&u2);
301 bigint_sub_s(&u2, &u2, &u1);
302 bigint_sub_s(&u2, &u2, &u1);
303 curve->reduce_p(&u2);
304 bigint_copy(&dest->x, &u2);
307 bigint_sub_s(&u1, &u1, &u2);
308 curve->reduce_p(&u1);
309 bigint_mul_s(&s2, &u1, &r);
310 curve->reduce_p(&s2);
311 bigint_mul_s(&s1, &s1, &h);
312 curve->reduce_p(&s1);
313 bigint_sub_s(&s2, &s2, &s1);
314 curve->reduce_p(&s2);
315 bigint_copy(&dest->y, &s2);
319 bigint_square(&s1, &dest->z1);
320 curve->reduce_p(&s1);
321 bigint_copy(&dest->z2, &s1);
324 bigint_mul_u(&s1, &s1, &dest->z1);
325 curve->reduce_p(&s1);
326 bigint_copy(&dest->z3, &s1);
331 uint8_t ecc_chudnovsky_double_and_add(ecc_chudnovsky_point_t *dest,
333 const ecc_chudnovsky_point_t *p,
334 const ecc_curve_sp_t* curve){
339 for(i = k->length_W; i > 0; --i){
340 v = 1 << (BIGINT_WORD_SIZE - 1);
344 ecc_chudnovsky_point_double_sp(dest, dest, curve);
346 ecc_chudnovsky_point_add_sp(dest, dest, p, curve);
351 ecc_chudnovsky_point_copy(dest, p);
360 uint8_t bigint_to_naf(uint8_t* dest, uint16_t *length, const bigint_t *src){
361 if(src->length_W == 0){
367 memset(dest, 0, src->length_W * sizeof(bigint_word_t));
370 uint8_t t; /* 3 -> -1 ; 1 -> 1; 0 -> 0 (2 should not happen) */
372 bigint_word_t k_w[src->length_W];
373 bigint_word_t p_w = 1;
378 bigint_copy(&k, src);
380 while(k.length_W >= 1){
384 bigint_sub_u(&k, &k, &p);
386 bigint_add_u(&k, &k, &p);
391 dest[(i * 2) / 8] |= t << ((2 * i) & 7);
392 bigint_shiftright(&k, 1);
399 void print_naf(uint8_t* naf, uint16_t length){
406 t = (naf[(length * 2) / 8] >> ((length * 2) & 7)) & 3;
408 case 0: putchar('0'); break;
409 case 1: putchar('1'); break;
410 case 3: putchar('-'); putchar('1'); break;
411 default: putchar('E');
419 uint8_t ecc_chudnovsky_naf_multiplication(ecc_chudnovsky_point_t *dest,
421 const ecc_chudnovsky_point_t *p,
422 const ecc_curve_sp_t* curve){
423 if(k->length_W == 0 || p->y.length_W == 0){
424 bigint_set_zero(&dest->y);
430 ecc_chudnovsky_point_t p_;
431 bigint_word_t y_[curve->p->length_W];
435 memcpy(&p_, p, sizeof(p_));
437 bigint_copy(&p_.y, &p->y);
438 p_.y.info |= BIGINT_NEG_MASK;
439 bigint_add_s(&p_.y, &p_.y, curve->p);
442 if(!(t = malloc(k->length_W * sizeof(bigint_word_t) * 2))){
445 bigint_to_naf(t, &i, k);
448 dest->y.length_W = 0;
450 q = (t[(i * 2) / 8] >> ((i * 2) & 7)) & 3;
451 ecc_chudnovsky_point_double_sp(dest, dest, curve);
453 ecc_chudnovsky_point_add_sp(dest, dest, p, curve);
456 ecc_chudnovsky_point_add_sp(dest, dest, &p_, curve);
465 uint8_t ecc_chudnovsky_multiplication(ecc_chudnovsky_point_t *dest,
467 const ecc_chudnovsky_point_t *p,
468 const ecc_curve_sp_t* curve){
469 return ecc_chudnovsky_naf_multiplication(dest, k, p, curve);