diff options
Diffstat (limited to '')
-rw-r--r-- | src/lib/libcrypto/ec/ec_mult.c | 752 |
1 files changed, 354 insertions, 398 deletions
diff --git a/src/lib/libcrypto/ec/ec_mult.c b/src/lib/libcrypto/ec/ec_mult.c index b48c888048..c0525c4940 100644 --- a/src/lib/libcrypto/ec/ec_mult.c +++ b/src/lib/libcrypto/ec/ec_mult.c | |||
@@ -10,7 +10,7 @@ | |||
10 | * are met: | 10 | * are met: |
11 | * | 11 | * |
12 | * 1. Redistributions of source code must retain the above copyright | 12 | * 1. Redistributions of source code must retain the above copyright |
13 | * notice, this list of conditions and the following disclaimer. | 13 | * notice, this list of conditions and the following disclaimer. |
14 | * | 14 | * |
15 | * 2. Redistributions in binary form must reproduce the above copyright | 15 | * 2. Redistributions in binary form must reproduce the above copyright |
16 | * notice, this list of conditions and the following disclaimer in | 16 | * notice, this list of conditions and the following disclaimer in |
@@ -80,46 +80,49 @@ | |||
80 | 80 | ||
81 | /* structure for precomputed multiples of the generator */ | 81 | /* structure for precomputed multiples of the generator */ |
82 | typedef struct ec_pre_comp_st { | 82 | typedef struct ec_pre_comp_st { |
83 | const EC_GROUP *group; /* parent EC_GROUP object */ | 83 | const EC_GROUP *group; /* parent EC_GROUP object */ |
84 | size_t blocksize; /* block size for wNAF splitting */ | 84 | size_t blocksize; /* block size for wNAF splitting */ |
85 | size_t numblocks; /* max. number of blocks for which we have precomputation */ | 85 | size_t numblocks; /* max. number of blocks for which we have |
86 | size_t w; /* window size */ | 86 | * precomputation */ |
87 | EC_POINT **points; /* array with pre-calculated multiples of generator: | 87 | size_t w; /* window size */ |
88 | * 'num' pointers to EC_POINT objects followed by a NULL */ | 88 | EC_POINT **points; /* array with pre-calculated multiples of |
89 | size_t num; /* numblocks * 2^(w-1) */ | 89 | * generator: 'num' pointers to EC_POINT |
90 | * objects followed by a NULL */ | ||
91 | size_t num; /* numblocks * 2^(w-1) */ | ||
90 | int references; | 92 | int references; |
91 | } EC_PRE_COMP; | 93 | } EC_PRE_COMP; |
92 | 94 | ||
93 | /* functions to manage EC_PRE_COMP within the EC_GROUP extra_data framework */ | 95 | /* functions to manage EC_PRE_COMP within the EC_GROUP extra_data framework */ |
94 | static void *ec_pre_comp_dup(void *); | 96 | static void *ec_pre_comp_dup(void *); |
95 | static void ec_pre_comp_free(void *); | 97 | static void ec_pre_comp_free(void *); |
96 | static void ec_pre_comp_clear_free(void *); | 98 | static void ec_pre_comp_clear_free(void *); |
97 | 99 | ||
98 | static EC_PRE_COMP *ec_pre_comp_new(const EC_GROUP *group) | 100 | static EC_PRE_COMP * |
99 | { | 101 | ec_pre_comp_new(const EC_GROUP * group) |
102 | { | ||
100 | EC_PRE_COMP *ret = NULL; | 103 | EC_PRE_COMP *ret = NULL; |
101 | 104 | ||
102 | if (!group) | 105 | if (!group) |
103 | return NULL; | 106 | return NULL; |
104 | 107 | ||
105 | ret = (EC_PRE_COMP *)malloc(sizeof(EC_PRE_COMP)); | 108 | ret = (EC_PRE_COMP *) malloc(sizeof(EC_PRE_COMP)); |
106 | if (!ret) | 109 | if (!ret) { |
107 | { | ||
108 | ECerr(EC_F_EC_PRE_COMP_NEW, ERR_R_MALLOC_FAILURE); | 110 | ECerr(EC_F_EC_PRE_COMP_NEW, ERR_R_MALLOC_FAILURE); |
109 | return ret; | 111 | return ret; |
110 | } | 112 | } |
111 | ret->group = group; | 113 | ret->group = group; |
112 | ret->blocksize = 8; /* default */ | 114 | ret->blocksize = 8; /* default */ |
113 | ret->numblocks = 0; | 115 | ret->numblocks = 0; |
114 | ret->w = 4; /* default */ | 116 | ret->w = 4; /* default */ |
115 | ret->points = NULL; | 117 | ret->points = NULL; |
116 | ret->num = 0; | 118 | ret->num = 0; |
117 | ret->references = 1; | 119 | ret->references = 1; |
118 | return ret; | 120 | return ret; |
119 | } | 121 | } |
120 | 122 | ||
121 | static void *ec_pre_comp_dup(void *src_) | 123 | static void * |
122 | { | 124 | ec_pre_comp_dup(void *src_) |
125 | { | ||
123 | EC_PRE_COMP *src = src_; | 126 | EC_PRE_COMP *src = src_; |
124 | 127 | ||
125 | /* no need to actually copy, these objects never change! */ | 128 | /* no need to actually copy, these objects never change! */ |
@@ -127,10 +130,11 @@ static void *ec_pre_comp_dup(void *src_) | |||
127 | CRYPTO_add(&src->references, 1, CRYPTO_LOCK_EC_PRE_COMP); | 130 | CRYPTO_add(&src->references, 1, CRYPTO_LOCK_EC_PRE_COMP); |
128 | 131 | ||
129 | return src_; | 132 | return src_; |
130 | } | 133 | } |
131 | 134 | ||
132 | static void ec_pre_comp_free(void *pre_) | 135 | static void |
133 | { | 136 | ec_pre_comp_free(void *pre_) |
137 | { | ||
134 | int i; | 138 | int i; |
135 | EC_PRE_COMP *pre = pre_; | 139 | EC_PRE_COMP *pre = pre_; |
136 | 140 | ||
@@ -141,19 +145,19 @@ static void ec_pre_comp_free(void *pre_) | |||
141 | if (i > 0) | 145 | if (i > 0) |
142 | return; | 146 | return; |
143 | 147 | ||
144 | if (pre->points) | 148 | if (pre->points) { |
145 | { | ||
146 | EC_POINT **p; | 149 | EC_POINT **p; |
147 | 150 | ||
148 | for (p = pre->points; *p != NULL; p++) | 151 | for (p = pre->points; *p != NULL; p++) |
149 | EC_POINT_free(*p); | 152 | EC_POINT_free(*p); |
150 | free(pre->points); | 153 | free(pre->points); |
151 | } | ||
152 | free(pre); | ||
153 | } | 154 | } |
155 | free(pre); | ||
156 | } | ||
154 | 157 | ||
155 | static void ec_pre_comp_clear_free(void *pre_) | 158 | static void |
156 | { | 159 | ec_pre_comp_clear_free(void *pre_) |
160 | { | ||
157 | int i; | 161 | int i; |
158 | EC_PRE_COMP *pre = pre_; | 162 | EC_PRE_COMP *pre = pre_; |
159 | 163 | ||
@@ -164,20 +168,18 @@ static void ec_pre_comp_clear_free(void *pre_) | |||
164 | if (i > 0) | 168 | if (i > 0) |
165 | return; | 169 | return; |
166 | 170 | ||
167 | if (pre->points) | 171 | if (pre->points) { |
168 | { | ||
169 | EC_POINT **p; | 172 | EC_POINT **p; |
170 | 173 | ||
171 | for (p = pre->points; *p != NULL; p++) | 174 | for (p = pre->points; *p != NULL; p++) { |
172 | { | ||
173 | EC_POINT_clear_free(*p); | 175 | EC_POINT_clear_free(*p); |
174 | OPENSSL_cleanse(p, sizeof *p); | 176 | OPENSSL_cleanse(p, sizeof *p); |
175 | } | ||
176 | free(pre->points); | ||
177 | } | 177 | } |
178 | free(pre->points); | ||
179 | } | ||
178 | OPENSSL_cleanse(pre, sizeof *pre); | 180 | OPENSSL_cleanse(pre, sizeof *pre); |
179 | free(pre); | 181 | free(pre); |
180 | } | 182 | } |
181 | 183 | ||
182 | 184 | ||
183 | 185 | ||
@@ -190,138 +192,125 @@ static void ec_pre_comp_clear_free(void *pre_) | |||
190 | * with the exception that the most significant digit may be only | 192 | * with the exception that the most significant digit may be only |
191 | * w-1 zeros away from that next non-zero digit. | 193 | * w-1 zeros away from that next non-zero digit. |
192 | */ | 194 | */ |
193 | static signed char *compute_wNAF(const BIGNUM *scalar, int w, size_t *ret_len) | 195 | static signed char * |
194 | { | 196 | compute_wNAF(const BIGNUM * scalar, int w, size_t * ret_len) |
197 | { | ||
195 | int window_val; | 198 | int window_val; |
196 | int ok = 0; | 199 | int ok = 0; |
197 | signed char *r = NULL; | 200 | signed char *r = NULL; |
198 | int sign = 1; | 201 | int sign = 1; |
199 | int bit, next_bit, mask; | 202 | int bit, next_bit, mask; |
200 | size_t len = 0, j; | 203 | size_t len = 0, j; |
201 | 204 | ||
202 | if (BN_is_zero(scalar)) | 205 | if (BN_is_zero(scalar)) { |
203 | { | ||
204 | r = malloc(1); | 206 | r = malloc(1); |
205 | if (!r) | 207 | if (!r) { |
206 | { | ||
207 | ECerr(EC_F_COMPUTE_WNAF, ERR_R_MALLOC_FAILURE); | 208 | ECerr(EC_F_COMPUTE_WNAF, ERR_R_MALLOC_FAILURE); |
208 | goto err; | 209 | goto err; |
209 | } | 210 | } |
210 | r[0] = 0; | 211 | r[0] = 0; |
211 | *ret_len = 1; | 212 | *ret_len = 1; |
212 | return r; | 213 | return r; |
213 | } | 214 | } |
214 | 215 | if (w <= 0 || w > 7) { | |
215 | if (w <= 0 || w > 7) /* 'signed char' can represent integers with absolute values less than 2^7 */ | 216 | /* 'signed char' can represent integers with |
216 | { | 217 | * absolute values less than 2^7 */ |
217 | ECerr(EC_F_COMPUTE_WNAF, ERR_R_INTERNAL_ERROR); | 218 | ECerr(EC_F_COMPUTE_WNAF, ERR_R_INTERNAL_ERROR); |
218 | goto err; | 219 | goto err; |
219 | } | 220 | } |
220 | bit = 1 << w; /* at most 128 */ | 221 | bit = 1 << w; /* at most 128 */ |
221 | next_bit = bit << 1; /* at most 256 */ | 222 | next_bit = bit << 1; /* at most 256 */ |
222 | mask = next_bit - 1; /* at most 255 */ | 223 | mask = next_bit - 1; /* at most 255 */ |
223 | 224 | ||
224 | if (BN_is_negative(scalar)) | 225 | if (BN_is_negative(scalar)) { |
225 | { | ||
226 | sign = -1; | 226 | sign = -1; |
227 | } | 227 | } |
228 | 228 | if (scalar->d == NULL || scalar->top == 0) { | |
229 | if (scalar->d == NULL || scalar->top == 0) | ||
230 | { | ||
231 | ECerr(EC_F_COMPUTE_WNAF, ERR_R_INTERNAL_ERROR); | 229 | ECerr(EC_F_COMPUTE_WNAF, ERR_R_INTERNAL_ERROR); |
232 | goto err; | 230 | goto err; |
233 | } | 231 | } |
234 | |||
235 | len = BN_num_bits(scalar); | 232 | len = BN_num_bits(scalar); |
236 | r = malloc(len + 1); /* modified wNAF may be one digit longer than binary representation | 233 | r = malloc(len + 1); /* modified wNAF may be one digit longer than |
237 | * (*ret_len will be set to the actual length, i.e. at most | 234 | * binary representation (*ret_len will be |
238 | * BN_num_bits(scalar) + 1) */ | 235 | * set to the actual length, i.e. at most |
239 | if (r == NULL) | 236 | * BN_num_bits(scalar) + 1) */ |
240 | { | 237 | if (r == NULL) { |
241 | ECerr(EC_F_COMPUTE_WNAF, ERR_R_MALLOC_FAILURE); | 238 | ECerr(EC_F_COMPUTE_WNAF, ERR_R_MALLOC_FAILURE); |
242 | goto err; | 239 | goto err; |
243 | } | 240 | } |
244 | window_val = scalar->d[0] & mask; | 241 | window_val = scalar->d[0] & mask; |
245 | j = 0; | 242 | j = 0; |
246 | while ((window_val != 0) || (j + w + 1 < len)) /* if j+w+1 >= len, window_val will not increase */ | 243 | while ((window_val != 0) || (j + w + 1 < len)) { |
247 | { | 244 | /* if j+w+1 >= len, window_val will not increase */ |
248 | int digit = 0; | 245 | int digit = 0; |
249 | 246 | ||
250 | /* 0 <= window_val <= 2^(w+1) */ | 247 | /* 0 <= window_val <= 2^(w+1) */ |
251 | 248 | if (window_val & 1) { | |
252 | if (window_val & 1) | ||
253 | { | ||
254 | /* 0 < window_val < 2^(w+1) */ | 249 | /* 0 < window_val < 2^(w+1) */ |
255 | 250 | if (window_val & bit) { | |
256 | if (window_val & bit) | 251 | digit = window_val - next_bit; /* -2^w < digit < 0 */ |
257 | { | 252 | |
258 | digit = window_val - next_bit; /* -2^w < digit < 0 */ | 253 | #if 1 /* modified wNAF */ |
259 | 254 | if (j + w + 1 >= len) { | |
260 | #if 1 /* modified wNAF */ | 255 | /* |
261 | if (j + w + 1 >= len) | 256 | * special case for generating |
262 | { | 257 | * modified wNAFs: no new bits will |
263 | /* special case for generating modified wNAFs: | 258 | * be added into window_val, so using |
264 | * no new bits will be added into window_val, | 259 | * a positive digit here will |
265 | * so using a positive digit here will decrease | 260 | * decrease the total length of the |
266 | * the total length of the representation */ | 261 | * representation |
267 | 262 | */ | |
268 | digit = window_val & (mask >> 1); /* 0 < digit < 2^w */ | 263 | |
269 | } | 264 | digit = window_val & (mask >> 1); /* 0 < digit < 2^w */ |
270 | #endif | ||
271 | } | ||
272 | else | ||
273 | { | ||
274 | digit = window_val; /* 0 < digit < 2^w */ | ||
275 | } | 265 | } |
276 | 266 | #endif | |
277 | if (digit <= -bit || digit >= bit || !(digit & 1)) | 267 | } else { |
278 | { | 268 | digit = window_val; /* 0 < digit < 2^w */ |
269 | } | ||
270 | |||
271 | if (digit <= -bit || digit >= bit || !(digit & 1)) { | ||
279 | ECerr(EC_F_COMPUTE_WNAF, ERR_R_INTERNAL_ERROR); | 272 | ECerr(EC_F_COMPUTE_WNAF, ERR_R_INTERNAL_ERROR); |
280 | goto err; | 273 | goto err; |
281 | } | 274 | } |
282 | |||
283 | window_val -= digit; | 275 | window_val -= digit; |
284 | 276 | ||
285 | /* now window_val is 0 or 2^(w+1) in standard wNAF generation; | 277 | /* |
286 | * for modified window NAFs, it may also be 2^w | 278 | * now window_val is 0 or 2^(w+1) in standard wNAF |
279 | * generation; for modified window NAFs, it may also | ||
280 | * be 2^w | ||
287 | */ | 281 | */ |
288 | if (window_val != 0 && window_val != next_bit && window_val != bit) | 282 | if (window_val != 0 && window_val != next_bit && window_val != bit) { |
289 | { | ||
290 | ECerr(EC_F_COMPUTE_WNAF, ERR_R_INTERNAL_ERROR); | 283 | ECerr(EC_F_COMPUTE_WNAF, ERR_R_INTERNAL_ERROR); |
291 | goto err; | 284 | goto err; |
292 | } | ||
293 | } | 285 | } |
294 | 286 | } | |
295 | r[j++] = sign * digit; | 287 | r[j++] = sign * digit; |
296 | 288 | ||
297 | window_val >>= 1; | 289 | window_val >>= 1; |
298 | window_val += bit * BN_is_bit_set(scalar, j + w); | 290 | window_val += bit * BN_is_bit_set(scalar, j + w); |
299 | 291 | ||
300 | if (window_val > next_bit) | 292 | if (window_val > next_bit) { |
301 | { | ||
302 | ECerr(EC_F_COMPUTE_WNAF, ERR_R_INTERNAL_ERROR); | 293 | ECerr(EC_F_COMPUTE_WNAF, ERR_R_INTERNAL_ERROR); |
303 | goto err; | 294 | goto err; |
304 | } | ||
305 | } | 295 | } |
296 | } | ||
306 | 297 | ||
307 | if (j > len + 1) | 298 | if (j > len + 1) { |
308 | { | ||
309 | ECerr(EC_F_COMPUTE_WNAF, ERR_R_INTERNAL_ERROR); | 299 | ECerr(EC_F_COMPUTE_WNAF, ERR_R_INTERNAL_ERROR); |
310 | goto err; | 300 | goto err; |
311 | } | 301 | } |
312 | len = j; | 302 | len = j; |
313 | ok = 1; | 303 | ok = 1; |
314 | 304 | ||
315 | err: | 305 | err: |
316 | if (!ok) | 306 | if (!ok) { |
317 | { | ||
318 | free(r); | 307 | free(r); |
319 | r = NULL; | 308 | r = NULL; |
320 | } | 309 | } |
321 | if (ok) | 310 | if (ok) |
322 | *ret_len = len; | 311 | *ret_len = len; |
323 | return r; | 312 | return r; |
324 | } | 313 | } |
325 | 314 | ||
326 | 315 | ||
327 | /* TODO: table should be optimised for the wNAF-based implementation, | 316 | /* TODO: table should be optimised for the wNAF-based implementation, |
@@ -343,374 +332,353 @@ static signed char *compute_wNAF(const BIGNUM *scalar, int w, size_t *ret_len) | |||
343 | * scalar*generator | 332 | * scalar*generator |
344 | * in the addition if scalar != NULL | 333 | * in the addition if scalar != NULL |
345 | */ | 334 | */ |
346 | int ec_wNAF_mul(const EC_GROUP *group, EC_POINT *r, const BIGNUM *scalar, | 335 | int |
347 | size_t num, const EC_POINT *points[], const BIGNUM *scalars[], BN_CTX *ctx) | 336 | ec_wNAF_mul(const EC_GROUP * group, EC_POINT * r, const BIGNUM * scalar, |
348 | { | 337 | size_t num, const EC_POINT * points[], const BIGNUM * scalars[], BN_CTX * ctx) |
338 | { | ||
349 | BN_CTX *new_ctx = NULL; | 339 | BN_CTX *new_ctx = NULL; |
350 | const EC_POINT *generator = NULL; | 340 | const EC_POINT *generator = NULL; |
351 | EC_POINT *tmp = NULL; | 341 | EC_POINT *tmp = NULL; |
352 | size_t totalnum; | 342 | size_t totalnum; |
353 | size_t blocksize = 0, numblocks = 0; /* for wNAF splitting */ | 343 | size_t blocksize = 0, numblocks = 0; /* for wNAF splitting */ |
354 | size_t pre_points_per_block = 0; | 344 | size_t pre_points_per_block = 0; |
355 | size_t i, j; | 345 | size_t i, j; |
356 | int k; | 346 | int k; |
357 | int r_is_inverted = 0; | 347 | int r_is_inverted = 0; |
358 | int r_is_at_infinity = 1; | 348 | int r_is_at_infinity = 1; |
359 | size_t *wsize = NULL; /* individual window sizes */ | 349 | size_t *wsize = NULL; /* individual window sizes */ |
360 | signed char **wNAF = NULL; /* individual wNAFs */ | 350 | signed char **wNAF = NULL; /* individual wNAFs */ |
361 | size_t *wNAF_len = NULL; | 351 | size_t *wNAF_len = NULL; |
362 | size_t max_len = 0; | 352 | size_t max_len = 0; |
363 | size_t num_val; | 353 | size_t num_val; |
364 | EC_POINT **val = NULL; /* precomputation */ | 354 | EC_POINT **val = NULL; /* precomputation */ |
365 | EC_POINT **v; | 355 | EC_POINT **v; |
366 | EC_POINT ***val_sub = NULL; /* pointers to sub-arrays of 'val' or 'pre_comp->points' */ | 356 | EC_POINT ***val_sub = NULL; /* pointers to sub-arrays of 'val' or |
357 | * 'pre_comp->points' */ | ||
367 | const EC_PRE_COMP *pre_comp = NULL; | 358 | const EC_PRE_COMP *pre_comp = NULL; |
368 | int num_scalar = 0; /* flag: will be set to 1 if 'scalar' must be treated like other scalars, | 359 | int num_scalar = 0; /* flag: will be set to 1 if 'scalar' must be |
369 | * i.e. precomputation is not available */ | 360 | * treated like other scalars, i.e. |
361 | * precomputation is not available */ | ||
370 | int ret = 0; | 362 | int ret = 0; |
371 | 363 | ||
372 | if (group->meth != r->meth) | 364 | if (group->meth != r->meth) { |
373 | { | ||
374 | ECerr(EC_F_EC_WNAF_MUL, EC_R_INCOMPATIBLE_OBJECTS); | 365 | ECerr(EC_F_EC_WNAF_MUL, EC_R_INCOMPATIBLE_OBJECTS); |
375 | return 0; | 366 | return 0; |
376 | } | 367 | } |
377 | 368 | if ((scalar == NULL) && (num == 0)) { | |
378 | if ((scalar == NULL) && (num == 0)) | ||
379 | { | ||
380 | return EC_POINT_set_to_infinity(group, r); | 369 | return EC_POINT_set_to_infinity(group, r); |
381 | } | 370 | } |
382 | 371 | for (i = 0; i < num; i++) { | |
383 | for (i = 0; i < num; i++) | 372 | if (group->meth != points[i]->meth) { |
384 | { | ||
385 | if (group->meth != points[i]->meth) | ||
386 | { | ||
387 | ECerr(EC_F_EC_WNAF_MUL, EC_R_INCOMPATIBLE_OBJECTS); | 373 | ECerr(EC_F_EC_WNAF_MUL, EC_R_INCOMPATIBLE_OBJECTS); |
388 | return 0; | 374 | return 0; |
389 | } | ||
390 | } | 375 | } |
376 | } | ||
391 | 377 | ||
392 | if (ctx == NULL) | 378 | if (ctx == NULL) { |
393 | { | ||
394 | ctx = new_ctx = BN_CTX_new(); | 379 | ctx = new_ctx = BN_CTX_new(); |
395 | if (ctx == NULL) | 380 | if (ctx == NULL) |
396 | goto err; | 381 | goto err; |
397 | } | 382 | } |
398 | 383 | if (scalar != NULL) { | |
399 | if (scalar != NULL) | ||
400 | { | ||
401 | generator = EC_GROUP_get0_generator(group); | 384 | generator = EC_GROUP_get0_generator(group); |
402 | if (generator == NULL) | 385 | if (generator == NULL) { |
403 | { | ||
404 | ECerr(EC_F_EC_WNAF_MUL, EC_R_UNDEFINED_GENERATOR); | 386 | ECerr(EC_F_EC_WNAF_MUL, EC_R_UNDEFINED_GENERATOR); |
405 | goto err; | 387 | goto err; |
406 | } | 388 | } |
407 | |||
408 | /* look if we can use precomputed multiples of generator */ | 389 | /* look if we can use precomputed multiples of generator */ |
409 | 390 | ||
410 | pre_comp = EC_EX_DATA_get_data(group->extra_data, ec_pre_comp_dup, ec_pre_comp_free, ec_pre_comp_clear_free); | 391 | pre_comp = EC_EX_DATA_get_data(group->extra_data, ec_pre_comp_dup, ec_pre_comp_free, ec_pre_comp_clear_free); |
411 | 392 | ||
412 | if (pre_comp && pre_comp->numblocks && (EC_POINT_cmp(group, generator, pre_comp->points[0], ctx) == 0)) | 393 | if (pre_comp && pre_comp->numblocks && |
413 | { | 394 | (EC_POINT_cmp(group, generator, pre_comp->points[0], ctx) == 0)) { |
414 | blocksize = pre_comp->blocksize; | 395 | blocksize = pre_comp->blocksize; |
415 | 396 | ||
416 | /* determine maximum number of blocks that wNAF splitting may yield | 397 | /* |
417 | * (NB: maximum wNAF length is bit length plus one) */ | 398 | * determine maximum number of blocks that wNAF |
399 | * splitting may yield (NB: maximum wNAF length is | ||
400 | * bit length plus one) | ||
401 | */ | ||
418 | numblocks = (BN_num_bits(scalar) / blocksize) + 1; | 402 | numblocks = (BN_num_bits(scalar) / blocksize) + 1; |
419 | 403 | ||
420 | /* we cannot use more blocks than we have precomputation for */ | 404 | /* |
405 | * we cannot use more blocks than we have | ||
406 | * precomputation for | ||
407 | */ | ||
421 | if (numblocks > pre_comp->numblocks) | 408 | if (numblocks > pre_comp->numblocks) |
422 | numblocks = pre_comp->numblocks; | 409 | numblocks = pre_comp->numblocks; |
423 | 410 | ||
424 | pre_points_per_block = (size_t)1 << (pre_comp->w - 1); | 411 | pre_points_per_block = (size_t) 1 << (pre_comp->w - 1); |
425 | 412 | ||
426 | /* check that pre_comp looks sane */ | 413 | /* check that pre_comp looks sane */ |
427 | if (pre_comp->num != (pre_comp->numblocks * pre_points_per_block)) | 414 | if (pre_comp->num != (pre_comp->numblocks * pre_points_per_block)) { |
428 | { | ||
429 | ECerr(EC_F_EC_WNAF_MUL, ERR_R_INTERNAL_ERROR); | 415 | ECerr(EC_F_EC_WNAF_MUL, ERR_R_INTERNAL_ERROR); |
430 | goto err; | 416 | goto err; |
431 | } | ||
432 | } | 417 | } |
433 | else | 418 | } else { |
434 | { | ||
435 | /* can't use precomputation */ | 419 | /* can't use precomputation */ |
436 | pre_comp = NULL; | 420 | pre_comp = NULL; |
437 | numblocks = 1; | 421 | numblocks = 1; |
438 | num_scalar = 1; /* treat 'scalar' like 'num'-th element of 'scalars' */ | 422 | num_scalar = 1; /* treat 'scalar' like 'num'-th |
439 | } | 423 | * element of 'scalars' */ |
440 | } | 424 | } |
441 | 425 | } | |
442 | totalnum = num + numblocks; | 426 | totalnum = num + numblocks; |
443 | 427 | ||
444 | wsize = malloc(totalnum * sizeof wsize[0]); | 428 | wsize = malloc(totalnum * sizeof wsize[0]); |
445 | wNAF_len = malloc(totalnum * sizeof wNAF_len[0]); | 429 | wNAF_len = malloc(totalnum * sizeof wNAF_len[0]); |
446 | wNAF = malloc((totalnum + 1) * sizeof wNAF[0]); /* includes space for pivot */ | 430 | wNAF = malloc((totalnum + 1) * sizeof wNAF[0]); /* includes space for |
447 | val_sub = malloc(totalnum * sizeof val_sub[0]); | 431 | * pivot */ |
448 | 432 | val_sub = malloc(totalnum * sizeof val_sub[0]); | |
449 | if (!wsize || !wNAF_len || !wNAF || !val_sub) | 433 | |
450 | { | 434 | if (!wsize || !wNAF_len || !wNAF || !val_sub) { |
451 | ECerr(EC_F_EC_WNAF_MUL, ERR_R_MALLOC_FAILURE); | 435 | ECerr(EC_F_EC_WNAF_MUL, ERR_R_MALLOC_FAILURE); |
452 | goto err; | 436 | goto err; |
453 | } | 437 | } |
454 | 438 | wNAF[0] = NULL; /* preliminary pivot */ | |
455 | wNAF[0] = NULL; /* preliminary pivot */ | ||
456 | 439 | ||
457 | /* num_val will be the total number of temporarily precomputed points */ | 440 | /* num_val will be the total number of temporarily precomputed points */ |
458 | num_val = 0; | 441 | num_val = 0; |
459 | 442 | ||
460 | for (i = 0; i < num + num_scalar; i++) | 443 | for (i = 0; i < num + num_scalar; i++) { |
461 | { | ||
462 | size_t bits; | 444 | size_t bits; |
463 | 445 | ||
464 | bits = i < num ? BN_num_bits(scalars[i]) : BN_num_bits(scalar); | 446 | bits = i < num ? BN_num_bits(scalars[i]) : BN_num_bits(scalar); |
465 | wsize[i] = EC_window_bits_for_scalar_size(bits); | 447 | wsize[i] = EC_window_bits_for_scalar_size(bits); |
466 | num_val += (size_t)1 << (wsize[i] - 1); | 448 | num_val += (size_t) 1 << (wsize[i] - 1); |
467 | wNAF[i + 1] = NULL; /* make sure we always have a pivot */ | 449 | wNAF[i + 1] = NULL; /* make sure we always have a pivot */ |
468 | wNAF[i] = compute_wNAF((i < num ? scalars[i] : scalar), wsize[i], &wNAF_len[i]); | 450 | wNAF[i] = compute_wNAF((i < num ? scalars[i] : scalar), wsize[i], &wNAF_len[i]); |
469 | if (wNAF[i] == NULL) | 451 | if (wNAF[i] == NULL) |
470 | goto err; | 452 | goto err; |
471 | if (wNAF_len[i] > max_len) | 453 | if (wNAF_len[i] > max_len) |
472 | max_len = wNAF_len[i]; | 454 | max_len = wNAF_len[i]; |
473 | } | 455 | } |
474 | 456 | ||
475 | if (numblocks) | 457 | if (numblocks) { |
476 | { | ||
477 | /* we go here iff scalar != NULL */ | 458 | /* we go here iff scalar != NULL */ |
478 | 459 | ||
479 | if (pre_comp == NULL) | 460 | if (pre_comp == NULL) { |
480 | { | 461 | if (num_scalar != 1) { |
481 | if (num_scalar != 1) | ||
482 | { | ||
483 | ECerr(EC_F_EC_WNAF_MUL, ERR_R_INTERNAL_ERROR); | 462 | ECerr(EC_F_EC_WNAF_MUL, ERR_R_INTERNAL_ERROR); |
484 | goto err; | 463 | goto err; |
485 | } | ||
486 | /* we have already generated a wNAF for 'scalar' */ | ||
487 | } | 464 | } |
488 | else | 465 | /* we have already generated a wNAF for 'scalar' */ |
489 | { | 466 | } else { |
490 | signed char *tmp_wNAF = NULL; | 467 | signed char *tmp_wNAF = NULL; |
491 | size_t tmp_len = 0; | 468 | size_t tmp_len = 0; |
492 | 469 | ||
493 | if (num_scalar != 0) | 470 | if (num_scalar != 0) { |
494 | { | ||
495 | ECerr(EC_F_EC_WNAF_MUL, ERR_R_INTERNAL_ERROR); | 471 | ECerr(EC_F_EC_WNAF_MUL, ERR_R_INTERNAL_ERROR); |
496 | goto err; | 472 | goto err; |
497 | } | 473 | } |
498 | 474 | /* | |
499 | /* use the window size for which we have precomputation */ | 475 | * use the window size for which we have |
476 | * precomputation | ||
477 | */ | ||
500 | wsize[num] = pre_comp->w; | 478 | wsize[num] = pre_comp->w; |
501 | tmp_wNAF = compute_wNAF(scalar, wsize[num], &tmp_len); | 479 | tmp_wNAF = compute_wNAF(scalar, wsize[num], &tmp_len); |
502 | if (!tmp_wNAF) | 480 | if (!tmp_wNAF) |
503 | goto err; | 481 | goto err; |
504 | 482 | ||
505 | if (tmp_len <= max_len) | 483 | if (tmp_len <= max_len) { |
506 | { | 484 | /* |
507 | /* One of the other wNAFs is at least as long | 485 | * One of the other wNAFs is at least as long |
508 | * as the wNAF belonging to the generator, | 486 | * as the wNAF belonging to the generator, so |
509 | * so wNAF splitting will not buy us anything. */ | 487 | * wNAF splitting will not buy us anything. |
488 | */ | ||
510 | 489 | ||
511 | numblocks = 1; | 490 | numblocks = 1; |
512 | totalnum = num + 1; /* don't use wNAF splitting */ | 491 | totalnum = num + 1; /* don't use wNAF |
492 | * splitting */ | ||
513 | wNAF[num] = tmp_wNAF; | 493 | wNAF[num] = tmp_wNAF; |
514 | wNAF[num + 1] = NULL; | 494 | wNAF[num + 1] = NULL; |
515 | wNAF_len[num] = tmp_len; | 495 | wNAF_len[num] = tmp_len; |
516 | if (tmp_len > max_len) | 496 | if (tmp_len > max_len) |
517 | max_len = tmp_len; | 497 | max_len = tmp_len; |
518 | /* pre_comp->points starts with the points that we need here: */ | 498 | /* |
499 | * pre_comp->points starts with the points | ||
500 | * that we need here: | ||
501 | */ | ||
519 | val_sub[num] = pre_comp->points; | 502 | val_sub[num] = pre_comp->points; |
520 | } | 503 | } else { |
521 | else | 504 | /* |
522 | { | 505 | * don't include tmp_wNAF directly into wNAF |
523 | /* don't include tmp_wNAF directly into wNAF array | 506 | * array - use wNAF splitting and include the |
524 | * - use wNAF splitting and include the blocks */ | 507 | * blocks |
508 | */ | ||
525 | 509 | ||
526 | signed char *pp; | 510 | signed char *pp; |
527 | EC_POINT **tmp_points; | 511 | EC_POINT **tmp_points; |
528 | 512 | ||
529 | if (tmp_len < numblocks * blocksize) | 513 | if (tmp_len < numblocks * blocksize) { |
530 | { | 514 | /* |
531 | /* possibly we can do with fewer blocks than estimated */ | 515 | * possibly we can do with fewer |
516 | * blocks than estimated | ||
517 | */ | ||
532 | numblocks = (tmp_len + blocksize - 1) / blocksize; | 518 | numblocks = (tmp_len + blocksize - 1) / blocksize; |
533 | if (numblocks > pre_comp->numblocks) | 519 | if (numblocks > pre_comp->numblocks) { |
534 | { | ||
535 | ECerr(EC_F_EC_WNAF_MUL, ERR_R_INTERNAL_ERROR); | 520 | ECerr(EC_F_EC_WNAF_MUL, ERR_R_INTERNAL_ERROR); |
536 | goto err; | 521 | goto err; |
537 | } | ||
538 | totalnum = num + numblocks; | ||
539 | } | 522 | } |
540 | 523 | totalnum = num + numblocks; | |
524 | } | ||
541 | /* split wNAF in 'numblocks' parts */ | 525 | /* split wNAF in 'numblocks' parts */ |
542 | pp = tmp_wNAF; | 526 | pp = tmp_wNAF; |
543 | tmp_points = pre_comp->points; | 527 | tmp_points = pre_comp->points; |
544 | 528 | ||
545 | for (i = num; i < totalnum; i++) | 529 | for (i = num; i < totalnum; i++) { |
546 | { | 530 | if (i < totalnum - 1) { |
547 | if (i < totalnum - 1) | ||
548 | { | ||
549 | wNAF_len[i] = blocksize; | 531 | wNAF_len[i] = blocksize; |
550 | if (tmp_len < blocksize) | 532 | if (tmp_len < blocksize) { |
551 | { | ||
552 | ECerr(EC_F_EC_WNAF_MUL, ERR_R_INTERNAL_ERROR); | 533 | ECerr(EC_F_EC_WNAF_MUL, ERR_R_INTERNAL_ERROR); |
553 | goto err; | 534 | goto err; |
554 | } | ||
555 | tmp_len -= blocksize; | ||
556 | } | 535 | } |
557 | else | 536 | tmp_len -= blocksize; |
558 | /* last block gets whatever is left | 537 | } else |
559 | * (this could be more or less than 'blocksize'!) */ | 538 | /* |
539 | * last block gets whatever | ||
540 | * is left (this could be | ||
541 | * more or less than | ||
542 | * 'blocksize'!) | ||
543 | */ | ||
560 | wNAF_len[i] = tmp_len; | 544 | wNAF_len[i] = tmp_len; |
561 | 545 | ||
562 | wNAF[i + 1] = NULL; | 546 | wNAF[i + 1] = NULL; |
563 | wNAF[i] = malloc(wNAF_len[i]); | 547 | wNAF[i] = malloc(wNAF_len[i]); |
564 | if (wNAF[i] == NULL) | 548 | if (wNAF[i] == NULL) { |
565 | { | ||
566 | ECerr(EC_F_EC_WNAF_MUL, ERR_R_MALLOC_FAILURE); | 549 | ECerr(EC_F_EC_WNAF_MUL, ERR_R_MALLOC_FAILURE); |
567 | free(tmp_wNAF); | 550 | free(tmp_wNAF); |
568 | goto err; | 551 | goto err; |
569 | } | 552 | } |
570 | memcpy(wNAF[i], pp, wNAF_len[i]); | 553 | memcpy(wNAF[i], pp, wNAF_len[i]); |
571 | if (wNAF_len[i] > max_len) | 554 | if (wNAF_len[i] > max_len) |
572 | max_len = wNAF_len[i]; | 555 | max_len = wNAF_len[i]; |
573 | 556 | ||
574 | if (*tmp_points == NULL) | 557 | if (*tmp_points == NULL) { |
575 | { | ||
576 | ECerr(EC_F_EC_WNAF_MUL, ERR_R_INTERNAL_ERROR); | 558 | ECerr(EC_F_EC_WNAF_MUL, ERR_R_INTERNAL_ERROR); |
577 | free(tmp_wNAF); | 559 | free(tmp_wNAF); |
578 | goto err; | 560 | goto err; |
579 | } | 561 | } |
580 | val_sub[i] = tmp_points; | 562 | val_sub[i] = tmp_points; |
581 | tmp_points += pre_points_per_block; | 563 | tmp_points += pre_points_per_block; |
582 | pp += blocksize; | 564 | pp += blocksize; |
583 | } | ||
584 | free(tmp_wNAF); | ||
585 | } | 565 | } |
566 | free(tmp_wNAF); | ||
586 | } | 567 | } |
587 | } | 568 | } |
588 | 569 | } | |
589 | /* All points we precompute now go into a single array 'val'. | 570 | /* |
590 | * 'val_sub[i]' is a pointer to the subarray for the i-th point, | 571 | * All points we precompute now go into a single array 'val'. |
591 | * or to a subarray of 'pre_comp->points' if we already have precomputation. */ | 572 | * 'val_sub[i]' is a pointer to the subarray for the i-th point, or |
573 | * to a subarray of 'pre_comp->points' if we already have | ||
574 | * precomputation. | ||
575 | */ | ||
592 | val = malloc((num_val + 1) * sizeof val[0]); | 576 | val = malloc((num_val + 1) * sizeof val[0]); |
593 | if (val == NULL) | 577 | if (val == NULL) { |
594 | { | ||
595 | ECerr(EC_F_EC_WNAF_MUL, ERR_R_MALLOC_FAILURE); | 578 | ECerr(EC_F_EC_WNAF_MUL, ERR_R_MALLOC_FAILURE); |
596 | goto err; | 579 | goto err; |
597 | } | 580 | } |
598 | val[num_val] = NULL; /* pivot element */ | 581 | val[num_val] = NULL; /* pivot element */ |
599 | 582 | ||
600 | /* allocate points for precomputation */ | 583 | /* allocate points for precomputation */ |
601 | v = val; | 584 | v = val; |
602 | for (i = 0; i < num + num_scalar; i++) | 585 | for (i = 0; i < num + num_scalar; i++) { |
603 | { | ||
604 | val_sub[i] = v; | 586 | val_sub[i] = v; |
605 | for (j = 0; j < ((size_t)1 << (wsize[i] - 1)); j++) | 587 | for (j = 0; j < ((size_t) 1 << (wsize[i] - 1)); j++) { |
606 | { | ||
607 | *v = EC_POINT_new(group); | 588 | *v = EC_POINT_new(group); |
608 | if (*v == NULL) goto err; | 589 | if (*v == NULL) |
590 | goto err; | ||
609 | v++; | 591 | v++; |
610 | } | ||
611 | } | 592 | } |
612 | if (!(v == val + num_val)) | 593 | } |
613 | { | 594 | if (!(v == val + num_val)) { |
614 | ECerr(EC_F_EC_WNAF_MUL, ERR_R_INTERNAL_ERROR); | 595 | ECerr(EC_F_EC_WNAF_MUL, ERR_R_INTERNAL_ERROR); |
615 | goto err; | 596 | goto err; |
616 | } | 597 | } |
617 | |||
618 | if (!(tmp = EC_POINT_new(group))) | 598 | if (!(tmp = EC_POINT_new(group))) |
619 | goto err; | 599 | goto err; |
620 | 600 | ||
621 | /* prepare precomputed values: | 601 | /* |
622 | * val_sub[i][0] := points[i] | 602 | * prepare precomputed values: val_sub[i][0] := points[i] |
623 | * val_sub[i][1] := 3 * points[i] | 603 | * val_sub[i][1] := 3 * points[i] val_sub[i][2] := 5 * points[i] ... |
624 | * val_sub[i][2] := 5 * points[i] | ||
625 | * ... | ||
626 | */ | 604 | */ |
627 | for (i = 0; i < num + num_scalar; i++) | 605 | for (i = 0; i < num + num_scalar; i++) { |
628 | { | 606 | if (i < num) { |
629 | if (i < num) | 607 | if (!EC_POINT_copy(val_sub[i][0], points[i])) |
630 | { | 608 | goto err; |
631 | if (!EC_POINT_copy(val_sub[i][0], points[i])) goto err; | 609 | } else { |
632 | } | 610 | if (!EC_POINT_copy(val_sub[i][0], generator)) |
633 | else | 611 | goto err; |
634 | { | 612 | } |
635 | if (!EC_POINT_copy(val_sub[i][0], generator)) goto err; | ||
636 | } | ||
637 | 613 | ||
638 | if (wsize[i] > 1) | 614 | if (wsize[i] > 1) { |
639 | { | 615 | if (!EC_POINT_dbl(group, tmp, val_sub[i][0], ctx)) |
640 | if (!EC_POINT_dbl(group, tmp, val_sub[i][0], ctx)) goto err; | 616 | goto err; |
641 | for (j = 1; j < ((size_t)1 << (wsize[i] - 1)); j++) | 617 | for (j = 1; j < ((size_t) 1 << (wsize[i] - 1)); j++) { |
642 | { | 618 | if (!EC_POINT_add(group, val_sub[i][j], val_sub[i][j - 1], tmp, ctx)) |
643 | if (!EC_POINT_add(group, val_sub[i][j], val_sub[i][j - 1], tmp, ctx)) goto err; | 619 | goto err; |
644 | } | ||
645 | } | 620 | } |
646 | } | 621 | } |
622 | } | ||
647 | 623 | ||
648 | #if 1 /* optional; EC_window_bits_for_scalar_size assumes we do this step */ | 624 | #if 1 /* optional; EC_window_bits_for_scalar_size |
625 | * assumes we do this step */ | ||
649 | if (!EC_POINTs_make_affine(group, num_val, val, ctx)) | 626 | if (!EC_POINTs_make_affine(group, num_val, val, ctx)) |
650 | goto err; | 627 | goto err; |
651 | #endif | 628 | #endif |
652 | 629 | ||
653 | r_is_at_infinity = 1; | 630 | r_is_at_infinity = 1; |
654 | 631 | ||
655 | for (k = max_len - 1; k >= 0; k--) | 632 | for (k = max_len - 1; k >= 0; k--) { |
656 | { | 633 | if (!r_is_at_infinity) { |
657 | if (!r_is_at_infinity) | 634 | if (!EC_POINT_dbl(group, r, r, ctx)) |
658 | { | 635 | goto err; |
659 | if (!EC_POINT_dbl(group, r, r, ctx)) goto err; | 636 | } |
660 | } | 637 | for (i = 0; i < totalnum; i++) { |
661 | 638 | if (wNAF_len[i] > (size_t) k) { | |
662 | for (i = 0; i < totalnum; i++) | ||
663 | { | ||
664 | if (wNAF_len[i] > (size_t)k) | ||
665 | { | ||
666 | int digit = wNAF[i][k]; | 639 | int digit = wNAF[i][k]; |
667 | int is_neg; | 640 | int is_neg; |
668 | 641 | ||
669 | if (digit) | 642 | if (digit) { |
670 | { | ||
671 | is_neg = digit < 0; | 643 | is_neg = digit < 0; |
672 | 644 | ||
673 | if (is_neg) | 645 | if (is_neg) |
674 | digit = -digit; | 646 | digit = -digit; |
675 | 647 | ||
676 | if (is_neg != r_is_inverted) | 648 | if (is_neg != r_is_inverted) { |
677 | { | 649 | if (!r_is_at_infinity) { |
678 | if (!r_is_at_infinity) | 650 | if (!EC_POINT_invert(group, r, ctx)) |
679 | { | 651 | goto err; |
680 | if (!EC_POINT_invert(group, r, ctx)) goto err; | ||
681 | } | ||
682 | r_is_inverted = !r_is_inverted; | ||
683 | } | 652 | } |
684 | 653 | r_is_inverted = !r_is_inverted; | |
654 | } | ||
685 | /* digit > 0 */ | 655 | /* digit > 0 */ |
686 | 656 | ||
687 | if (r_is_at_infinity) | 657 | if (r_is_at_infinity) { |
688 | { | 658 | if (!EC_POINT_copy(r, val_sub[i][digit >> 1])) |
689 | if (!EC_POINT_copy(r, val_sub[i][digit >> 1])) goto err; | 659 | goto err; |
690 | r_is_at_infinity = 0; | 660 | r_is_at_infinity = 0; |
691 | } | 661 | } else { |
692 | else | 662 | if (!EC_POINT_add(group, r, r, val_sub[i][digit >> 1], ctx)) |
693 | { | 663 | goto err; |
694 | if (!EC_POINT_add(group, r, r, val_sub[i][digit >> 1], ctx)) goto err; | ||
695 | } | ||
696 | } | 664 | } |
697 | } | 665 | } |
698 | } | 666 | } |
699 | } | 667 | } |
668 | } | ||
700 | 669 | ||
701 | if (r_is_at_infinity) | 670 | if (r_is_at_infinity) { |
702 | { | 671 | if (!EC_POINT_set_to_infinity(group, r)) |
703 | if (!EC_POINT_set_to_infinity(group, r)) goto err; | 672 | goto err; |
704 | } | 673 | } else { |
705 | else | ||
706 | { | ||
707 | if (r_is_inverted) | 674 | if (r_is_inverted) |
708 | if (!EC_POINT_invert(group, r, ctx)) goto err; | 675 | if (!EC_POINT_invert(group, r, ctx)) |
709 | } | 676 | goto err; |
710 | 677 | } | |
678 | |||
711 | ret = 1; | 679 | ret = 1; |
712 | 680 | ||
713 | err: | 681 | err: |
714 | if (new_ctx != NULL) | 682 | if (new_ctx != NULL) |
715 | BN_CTX_free(new_ctx); | 683 | BN_CTX_free(new_ctx); |
716 | if (tmp != NULL) | 684 | if (tmp != NULL) |
@@ -719,34 +687,31 @@ int ec_wNAF_mul(const EC_GROUP *group, EC_POINT *r, const BIGNUM *scalar, | |||
719 | free(wsize); | 687 | free(wsize); |
720 | if (wNAF_len != NULL) | 688 | if (wNAF_len != NULL) |
721 | free(wNAF_len); | 689 | free(wNAF_len); |
722 | if (wNAF != NULL) | 690 | if (wNAF != NULL) { |
723 | { | ||
724 | signed char **w; | 691 | signed char **w; |
725 | 692 | ||
726 | for (w = wNAF; *w != NULL; w++) | 693 | for (w = wNAF; *w != NULL; w++) |
727 | free(*w); | 694 | free(*w); |
728 | 695 | ||
729 | free(wNAF); | 696 | free(wNAF); |
730 | } | 697 | } |
731 | if (val != NULL) | 698 | if (val != NULL) { |
732 | { | ||
733 | for (v = val; *v != NULL; v++) | 699 | for (v = val; *v != NULL; v++) |
734 | EC_POINT_clear_free(*v); | 700 | EC_POINT_clear_free(*v); |
735 | 701 | ||
736 | free(val); | 702 | free(val); |
737 | } | 703 | } |
738 | if (val_sub != NULL) | 704 | if (val_sub != NULL) { |
739 | { | ||
740 | free(val_sub); | 705 | free(val_sub); |
741 | } | ||
742 | return ret; | ||
743 | } | 706 | } |
707 | return ret; | ||
708 | } | ||
744 | 709 | ||
745 | 710 | ||
746 | /* ec_wNAF_precompute_mult() | 711 | /* ec_wNAF_precompute_mult() |
747 | * creates an EC_PRE_COMP object with preprecomputed multiples of the generator | 712 | * creates an EC_PRE_COMP object with preprecomputed multiples of the generator |
748 | * for use with wNAF splitting as implemented in ec_wNAF_mul(). | 713 | * for use with wNAF splitting as implemented in ec_wNAF_mul(). |
749 | * | 714 | * |
750 | * 'pre_comp->points' is an array of multiples of the generator | 715 | * 'pre_comp->points' is an array of multiples of the generator |
751 | * of the following form: | 716 | * of the following form: |
752 | * points[0] = generator; | 717 | * points[0] = generator; |
@@ -762,13 +727,15 @@ int ec_wNAF_mul(const EC_GROUP *group, EC_POINT *r, const BIGNUM *scalar, | |||
762 | * points[2^(w-1)*numblocks-1] = (2^(w-1)) * 2^(blocksize*(numblocks-1)) * generator | 727 | * points[2^(w-1)*numblocks-1] = (2^(w-1)) * 2^(blocksize*(numblocks-1)) * generator |
763 | * points[2^(w-1)*numblocks] = NULL | 728 | * points[2^(w-1)*numblocks] = NULL |
764 | */ | 729 | */ |
765 | int ec_wNAF_precompute_mult(EC_GROUP *group, BN_CTX *ctx) | 730 | int |
766 | { | 731 | ec_wNAF_precompute_mult(EC_GROUP * group, BN_CTX * ctx) |
732 | { | ||
767 | const EC_POINT *generator; | 733 | const EC_POINT *generator; |
768 | EC_POINT *tmp_point = NULL, *base = NULL, **var; | 734 | EC_POINT *tmp_point = NULL, *base = NULL, **var; |
769 | BN_CTX *new_ctx = NULL; | 735 | BN_CTX *new_ctx = NULL; |
770 | BIGNUM *order; | 736 | BIGNUM *order; |
771 | size_t i, bits, w, pre_points_per_block, blocksize, numblocks, num; | 737 | size_t i, bits, w, pre_points_per_block, blocksize, numblocks, |
738 | num; | ||
772 | EC_POINT **points = NULL; | 739 | EC_POINT **points = NULL; |
773 | EC_PRE_COMP *pre_comp; | 740 | EC_PRE_COMP *pre_comp; |
774 | int ret = 0; | 741 | int ret = 0; |
@@ -780,81 +747,72 @@ int ec_wNAF_precompute_mult(EC_GROUP *group, BN_CTX *ctx) | |||
780 | return 0; | 747 | return 0; |
781 | 748 | ||
782 | generator = EC_GROUP_get0_generator(group); | 749 | generator = EC_GROUP_get0_generator(group); |
783 | if (generator == NULL) | 750 | if (generator == NULL) { |
784 | { | ||
785 | ECerr(EC_F_EC_WNAF_PRECOMPUTE_MULT, EC_R_UNDEFINED_GENERATOR); | 751 | ECerr(EC_F_EC_WNAF_PRECOMPUTE_MULT, EC_R_UNDEFINED_GENERATOR); |
786 | goto err; | 752 | goto err; |
787 | } | 753 | } |
788 | 754 | if (ctx == NULL) { | |
789 | if (ctx == NULL) | ||
790 | { | ||
791 | ctx = new_ctx = BN_CTX_new(); | 755 | ctx = new_ctx = BN_CTX_new(); |
792 | if (ctx == NULL) | 756 | if (ctx == NULL) |
793 | goto err; | 757 | goto err; |
794 | } | 758 | } |
795 | |||
796 | BN_CTX_start(ctx); | 759 | BN_CTX_start(ctx); |
797 | order = BN_CTX_get(ctx); | 760 | order = BN_CTX_get(ctx); |
798 | if (order == NULL) goto err; | 761 | if (order == NULL) |
799 | |||
800 | if (!EC_GROUP_get_order(group, order, ctx)) goto err; | ||
801 | if (BN_is_zero(order)) | ||
802 | { | ||
803 | ECerr(EC_F_EC_WNAF_PRECOMPUTE_MULT, EC_R_UNKNOWN_ORDER); | ||
804 | goto err; | 762 | goto err; |
805 | } | ||
806 | 763 | ||
764 | if (!EC_GROUP_get_order(group, order, ctx)) | ||
765 | goto err; | ||
766 | if (BN_is_zero(order)) { | ||
767 | ECerr(EC_F_EC_WNAF_PRECOMPUTE_MULT, EC_R_UNKNOWN_ORDER); | ||
768 | goto err; | ||
769 | } | ||
807 | bits = BN_num_bits(order); | 770 | bits = BN_num_bits(order); |
808 | /* The following parameters mean we precompute (approximately) | 771 | /* |
809 | * one point per bit. | 772 | * The following parameters mean we precompute (approximately) one |
810 | * | 773 | * point per bit. |
811 | * TBD: The combination 8, 4 is perfect for 160 bits; for other | 774 | * |
812 | * bit lengths, other parameter combinations might provide better | 775 | * TBD: The combination 8, 4 is perfect for 160 bits; for other bit |
776 | * lengths, other parameter combinations might provide better | ||
813 | * efficiency. | 777 | * efficiency. |
814 | */ | 778 | */ |
815 | blocksize = 8; | 779 | blocksize = 8; |
816 | w = 4; | 780 | w = 4; |
817 | if (EC_window_bits_for_scalar_size(bits) > w) | 781 | if (EC_window_bits_for_scalar_size(bits) > w) { |
818 | { | ||
819 | /* let's not make the window too small ... */ | 782 | /* let's not make the window too small ... */ |
820 | w = EC_window_bits_for_scalar_size(bits); | 783 | w = EC_window_bits_for_scalar_size(bits); |
821 | } | 784 | } |
785 | numblocks = (bits + blocksize - 1) / blocksize; /* max. number of blocks | ||
786 | * to use for wNAF | ||
787 | * splitting */ | ||
822 | 788 | ||
823 | numblocks = (bits + blocksize - 1) / blocksize; /* max. number of blocks to use for wNAF splitting */ | 789 | pre_points_per_block = (size_t) 1 << (w - 1); |
824 | 790 | num = pre_points_per_block * numblocks; /* number of points to | |
825 | pre_points_per_block = (size_t)1 << (w - 1); | 791 | * compute and store */ |
826 | num = pre_points_per_block * numblocks; /* number of points to compute and store */ | ||
827 | 792 | ||
828 | points = malloc(sizeof (EC_POINT*)*(num + 1)); | 793 | points = malloc(sizeof(EC_POINT *) * (num + 1)); |
829 | if (!points) | 794 | if (!points) { |
830 | { | ||
831 | ECerr(EC_F_EC_WNAF_PRECOMPUTE_MULT, ERR_R_MALLOC_FAILURE); | 795 | ECerr(EC_F_EC_WNAF_PRECOMPUTE_MULT, ERR_R_MALLOC_FAILURE); |
832 | goto err; | 796 | goto err; |
833 | } | 797 | } |
834 | |||
835 | var = points; | 798 | var = points; |
836 | var[num] = NULL; /* pivot */ | 799 | var[num] = NULL; /* pivot */ |
837 | for (i = 0; i < num; i++) | 800 | for (i = 0; i < num; i++) { |
838 | { | 801 | if ((var[i] = EC_POINT_new(group)) == NULL) { |
839 | if ((var[i] = EC_POINT_new(group)) == NULL) | ||
840 | { | ||
841 | ECerr(EC_F_EC_WNAF_PRECOMPUTE_MULT, ERR_R_MALLOC_FAILURE); | 802 | ECerr(EC_F_EC_WNAF_PRECOMPUTE_MULT, ERR_R_MALLOC_FAILURE); |
842 | goto err; | 803 | goto err; |
843 | } | ||
844 | } | 804 | } |
805 | } | ||
845 | 806 | ||
846 | if (!(tmp_point = EC_POINT_new(group)) || !(base = EC_POINT_new(group))) | 807 | if (!(tmp_point = EC_POINT_new(group)) || !(base = EC_POINT_new(group))) { |
847 | { | ||
848 | ECerr(EC_F_EC_WNAF_PRECOMPUTE_MULT, ERR_R_MALLOC_FAILURE); | 808 | ECerr(EC_F_EC_WNAF_PRECOMPUTE_MULT, ERR_R_MALLOC_FAILURE); |
849 | goto err; | 809 | goto err; |
850 | } | 810 | } |
851 | |||
852 | if (!EC_POINT_copy(base, generator)) | 811 | if (!EC_POINT_copy(base, generator)) |
853 | goto err; | 812 | goto err; |
854 | 813 | ||
855 | /* do the precomputation */ | 814 | /* do the precomputation */ |
856 | for (i = 0; i < numblocks; i++) | 815 | for (i = 0; i < numblocks; i++) { |
857 | { | ||
858 | size_t j; | 816 | size_t j; |
859 | 817 | ||
860 | if (!EC_POINT_dbl(group, tmp_point, base, ctx)) | 818 | if (!EC_POINT_dbl(group, tmp_point, base, ctx)) |
@@ -863,37 +821,35 @@ int ec_wNAF_precompute_mult(EC_GROUP *group, BN_CTX *ctx) | |||
863 | if (!EC_POINT_copy(*var++, base)) | 821 | if (!EC_POINT_copy(*var++, base)) |
864 | goto err; | 822 | goto err; |
865 | 823 | ||
866 | for (j = 1; j < pre_points_per_block; j++, var++) | 824 | for (j = 1; j < pre_points_per_block; j++, var++) { |
867 | { | ||
868 | /* calculate odd multiples of the current base point */ | 825 | /* calculate odd multiples of the current base point */ |
869 | if (!EC_POINT_add(group, *var, tmp_point, *(var - 1), ctx)) | 826 | if (!EC_POINT_add(group, *var, tmp_point, *(var - 1), ctx)) |
870 | goto err; | 827 | goto err; |
871 | } | 828 | } |
872 | 829 | ||
873 | if (i < numblocks - 1) | 830 | if (i < numblocks - 1) { |
874 | { | 831 | /* |
875 | /* get the next base (multiply current one by 2^blocksize) */ | 832 | * get the next base (multiply current one by |
833 | * 2^blocksize) | ||
834 | */ | ||
876 | size_t k; | 835 | size_t k; |
877 | 836 | ||
878 | if (blocksize <= 2) | 837 | if (blocksize <= 2) { |
879 | { | ||
880 | ECerr(EC_F_EC_WNAF_PRECOMPUTE_MULT, ERR_R_INTERNAL_ERROR); | 838 | ECerr(EC_F_EC_WNAF_PRECOMPUTE_MULT, ERR_R_INTERNAL_ERROR); |
881 | goto err; | 839 | goto err; |
882 | } | 840 | } |
883 | |||
884 | if (!EC_POINT_dbl(group, base, tmp_point, ctx)) | 841 | if (!EC_POINT_dbl(group, base, tmp_point, ctx)) |
885 | goto err; | 842 | goto err; |
886 | for (k = 2; k < blocksize; k++) | 843 | for (k = 2; k < blocksize; k++) { |
887 | { | 844 | if (!EC_POINT_dbl(group, base, base, ctx)) |
888 | if (!EC_POINT_dbl(group,base,base,ctx)) | ||
889 | goto err; | 845 | goto err; |
890 | } | ||
891 | } | 846 | } |
892 | } | 847 | } |
848 | } | ||
893 | 849 | ||
894 | if (!EC_POINTs_make_affine(group, num, points, ctx)) | 850 | if (!EC_POINTs_make_affine(group, num, points, ctx)) |
895 | goto err; | 851 | goto err; |
896 | 852 | ||
897 | pre_comp->group = group; | 853 | pre_comp->group = group; |
898 | pre_comp->blocksize = blocksize; | 854 | pre_comp->blocksize = blocksize; |
899 | pre_comp->numblocks = numblocks; | 855 | pre_comp->numblocks = numblocks; |
@@ -908,33 +864,33 @@ int ec_wNAF_precompute_mult(EC_GROUP *group, BN_CTX *ctx) | |||
908 | pre_comp = NULL; | 864 | pre_comp = NULL; |
909 | 865 | ||
910 | ret = 1; | 866 | ret = 1; |
911 | err: | 867 | err: |
912 | if (ctx != NULL) | 868 | if (ctx != NULL) |
913 | BN_CTX_end(ctx); | 869 | BN_CTX_end(ctx); |
914 | if (new_ctx != NULL) | 870 | if (new_ctx != NULL) |
915 | BN_CTX_free(new_ctx); | 871 | BN_CTX_free(new_ctx); |
916 | if (pre_comp) | 872 | if (pre_comp) |
917 | ec_pre_comp_free(pre_comp); | 873 | ec_pre_comp_free(pre_comp); |
918 | if (points) | 874 | if (points) { |
919 | { | ||
920 | EC_POINT **p; | 875 | EC_POINT **p; |
921 | 876 | ||
922 | for (p = points; *p != NULL; p++) | 877 | for (p = points; *p != NULL; p++) |
923 | EC_POINT_free(*p); | 878 | EC_POINT_free(*p); |
924 | free(points); | 879 | free(points); |
925 | } | 880 | } |
926 | if (tmp_point) | 881 | if (tmp_point) |
927 | EC_POINT_free(tmp_point); | 882 | EC_POINT_free(tmp_point); |
928 | if (base) | 883 | if (base) |
929 | EC_POINT_free(base); | 884 | EC_POINT_free(base); |
930 | return ret; | 885 | return ret; |
931 | } | 886 | } |
932 | 887 | ||
933 | 888 | ||
934 | int ec_wNAF_have_precompute_mult(const EC_GROUP *group) | 889 | int |
935 | { | 890 | ec_wNAF_have_precompute_mult(const EC_GROUP * group) |
891 | { | ||
936 | if (EC_EX_DATA_get_data(group->extra_data, ec_pre_comp_dup, ec_pre_comp_free, ec_pre_comp_clear_free) != NULL) | 892 | if (EC_EX_DATA_get_data(group->extra_data, ec_pre_comp_dup, ec_pre_comp_free, ec_pre_comp_clear_free) != NULL) |
937 | return 1; | 893 | return 1; |
938 | else | 894 | else |
939 | return 0; | 895 | return 0; |
940 | } | 896 | } |