Adam Langley | d9e397b | 2015-01-22 14:27:53 -0800 | [diff] [blame] | 1 | /* ==================================================================== |
| 2 | * Copyright (c) 1998-2005 The OpenSSL Project. All rights reserved. |
| 3 | * |
| 4 | * Redistribution and use in source and binary forms, with or without |
| 5 | * modification, are permitted provided that the following conditions |
| 6 | * are met: |
| 7 | * |
| 8 | * 1. Redistributions of source code must retain the above copyright |
| 9 | * notice, this list of conditions and the following disclaimer. |
| 10 | * |
| 11 | * 2. Redistributions in binary form must reproduce the above copyright |
| 12 | * notice, this list of conditions and the following disclaimer in |
| 13 | * the documentation and/or other materials provided with the |
| 14 | * distribution. |
| 15 | * |
| 16 | * 3. All advertising materials mentioning features or use of this |
| 17 | * software must display the following acknowledgment: |
| 18 | * "This product includes software developed by the OpenSSL Project |
| 19 | * for use in the OpenSSL Toolkit. (http://www.OpenSSL.org/)" |
| 20 | * |
| 21 | * 4. The names "OpenSSL Toolkit" and "OpenSSL Project" must not be used to |
| 22 | * endorse or promote products derived from this software without |
| 23 | * prior written permission. For written permission, please contact |
| 24 | * openssl-core@OpenSSL.org. |
| 25 | * |
| 26 | * 5. Products derived from this software may not be called "OpenSSL" |
| 27 | * nor may "OpenSSL" appear in their names without prior written |
| 28 | * permission of the OpenSSL Project. |
| 29 | * |
| 30 | * 6. Redistributions of any form whatsoever must retain the following |
| 31 | * acknowledgment: |
| 32 | * "This product includes software developed by the OpenSSL Project |
| 33 | * for use in the OpenSSL Toolkit (http://www.OpenSSL.org/)" |
| 34 | * |
| 35 | * THIS SOFTWARE IS PROVIDED BY THE OpenSSL PROJECT ``AS IS'' AND ANY |
| 36 | * EXPRESSED OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE |
| 37 | * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR |
| 38 | * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE OpenSSL PROJECT OR |
| 39 | * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, |
| 40 | * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT |
| 41 | * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; |
| 42 | * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) |
| 43 | * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, |
| 44 | * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) |
| 45 | * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED |
| 46 | * OF THE POSSIBILITY OF SUCH DAMAGE. |
| 47 | * ==================================================================== |
| 48 | * |
| 49 | * This product includes cryptographic software written by Eric Young |
| 50 | * (eay@cryptsoft.com). This product includes software written by Tim |
| 51 | * Hudson (tjh@cryptsoft.com). */ |
| 52 | |
| 53 | #include <openssl/ecdsa.h> |
| 54 | |
| 55 | #include <string.h> |
| 56 | |
| 57 | #include <openssl/bn.h> |
| 58 | #include <openssl/err.h> |
| 59 | #include <openssl/mem.h> |
Adam Langley | d9e397b | 2015-01-22 14:27:53 -0800 | [diff] [blame] | 60 | |
| 61 | #include "../ec/internal.h" |
| 62 | |
| 63 | |
| 64 | int ECDSA_sign(int type, const uint8_t *digest, size_t digest_len, uint8_t *sig, |
| 65 | unsigned int *sig_len, EC_KEY *eckey) { |
| 66 | if (eckey->ecdsa_meth && eckey->ecdsa_meth->sign) { |
| 67 | return eckey->ecdsa_meth->sign(digest, digest_len, sig, sig_len, eckey); |
| 68 | } |
| 69 | |
| 70 | return ECDSA_sign_ex(type, digest, digest_len, sig, sig_len, NULL, NULL, |
| 71 | eckey); |
| 72 | } |
| 73 | |
| 74 | int ECDSA_verify(int type, const uint8_t *digest, size_t digest_len, |
| 75 | const uint8_t *sig, size_t sig_len, EC_KEY *eckey) { |
| 76 | ECDSA_SIG *s; |
| 77 | int ret = 0; |
| 78 | uint8_t *der = NULL; |
| 79 | |
| 80 | if (eckey->ecdsa_meth && eckey->ecdsa_meth->verify) { |
| 81 | return eckey->ecdsa_meth->verify(digest, digest_len, sig, sig_len, eckey); |
| 82 | } |
| 83 | |
| 84 | s = ECDSA_SIG_new(); |
| 85 | const uint8_t *sigp = sig; |
| 86 | if (s == NULL || d2i_ECDSA_SIG(&s, &sigp, sig_len) == NULL || |
| 87 | sigp != sig + sig_len) { |
| 88 | goto err; |
| 89 | } |
| 90 | |
| 91 | /* Ensure that the signature uses DER and doesn't have trailing garbage. */ |
| 92 | const int der_len = i2d_ECDSA_SIG(s, &der); |
| 93 | if (der_len < 0 || (size_t) der_len != sig_len || memcmp(sig, der, sig_len)) { |
| 94 | goto err; |
| 95 | } |
| 96 | |
| 97 | ret = ECDSA_do_verify(digest, digest_len, s, eckey); |
| 98 | |
| 99 | err: |
Adam Langley | e9ada86 | 2015-05-11 17:20:37 -0700 | [diff] [blame^] | 100 | OPENSSL_free(der); |
| 101 | ECDSA_SIG_free(s); |
Adam Langley | d9e397b | 2015-01-22 14:27:53 -0800 | [diff] [blame] | 102 | return ret; |
| 103 | } |
| 104 | |
| 105 | /* digest_to_bn interprets |digest_len| bytes from |digest| as a big-endian |
| 106 | * number and sets |out| to that value. It then truncates |out| so that it's, |
| 107 | * at most, as long as |order|. It returns one on success and zero otherwise. */ |
| 108 | static int digest_to_bn(BIGNUM *out, const uint8_t *digest, size_t digest_len, |
| 109 | const BIGNUM *order) { |
| 110 | size_t num_bits; |
| 111 | |
| 112 | num_bits = BN_num_bits(order); |
| 113 | /* Need to truncate digest if it is too long: first truncate whole |
| 114 | * bytes. */ |
| 115 | if (8 * digest_len > num_bits) { |
| 116 | digest_len = (num_bits + 7) / 8; |
| 117 | } |
| 118 | if (!BN_bin2bn(digest, digest_len, out)) { |
| 119 | OPENSSL_PUT_ERROR(ECDSA, digest_to_bn, ERR_R_BN_LIB); |
| 120 | return 0; |
| 121 | } |
| 122 | |
| 123 | /* If still too long truncate remaining bits with a shift */ |
| 124 | if ((8 * digest_len > num_bits) && |
| 125 | !BN_rshift(out, out, 8 - (num_bits & 0x7))) { |
| 126 | OPENSSL_PUT_ERROR(ECDSA, digest_to_bn, ERR_R_BN_LIB); |
| 127 | return 0; |
| 128 | } |
| 129 | |
| 130 | return 1; |
| 131 | } |
| 132 | |
| 133 | ECDSA_SIG *ECDSA_do_sign(const uint8_t *digest, size_t digest_len, |
| 134 | EC_KEY *key) { |
| 135 | return ECDSA_do_sign_ex(digest, digest_len, NULL, NULL, key); |
| 136 | } |
| 137 | |
| 138 | int ECDSA_do_verify(const uint8_t *digest, size_t digest_len, |
| 139 | const ECDSA_SIG *sig, EC_KEY *eckey) { |
| 140 | int ret = 0; |
| 141 | BN_CTX *ctx; |
| 142 | BIGNUM *order, *u1, *u2, *m, *X; |
| 143 | EC_POINT *point = NULL; |
| 144 | const EC_GROUP *group; |
| 145 | const EC_POINT *pub_key; |
| 146 | |
| 147 | if (eckey->ecdsa_meth && eckey->ecdsa_meth->verify) { |
| 148 | OPENSSL_PUT_ERROR(ECDSA, ECDSA_do_verify, ECDSA_R_NOT_IMPLEMENTED); |
| 149 | return 0; |
| 150 | } |
| 151 | |
| 152 | /* check input values */ |
| 153 | if ((group = EC_KEY_get0_group(eckey)) == NULL || |
| 154 | (pub_key = EC_KEY_get0_public_key(eckey)) == NULL || |
| 155 | sig == NULL) { |
| 156 | OPENSSL_PUT_ERROR(ECDSA, ECDSA_do_verify, ECDSA_R_MISSING_PARAMETERS); |
| 157 | return 0; |
| 158 | } |
| 159 | |
| 160 | ctx = BN_CTX_new(); |
| 161 | if (!ctx) { |
| 162 | OPENSSL_PUT_ERROR(ECDSA, ECDSA_do_verify, ERR_R_MALLOC_FAILURE); |
| 163 | return 0; |
| 164 | } |
| 165 | BN_CTX_start(ctx); |
| 166 | order = BN_CTX_get(ctx); |
| 167 | u1 = BN_CTX_get(ctx); |
| 168 | u2 = BN_CTX_get(ctx); |
| 169 | m = BN_CTX_get(ctx); |
| 170 | X = BN_CTX_get(ctx); |
| 171 | if (!X) { |
| 172 | OPENSSL_PUT_ERROR(ECDSA, ECDSA_do_verify, ERR_R_BN_LIB); |
| 173 | goto err; |
| 174 | } |
| 175 | |
| 176 | if (!EC_GROUP_get_order(group, order, ctx)) { |
| 177 | OPENSSL_PUT_ERROR(ECDSA, ECDSA_do_verify, ERR_R_EC_LIB); |
| 178 | goto err; |
| 179 | } |
| 180 | |
| 181 | if (BN_is_zero(sig->r) || BN_is_negative(sig->r) || |
| 182 | BN_ucmp(sig->r, order) >= 0 || BN_is_zero(sig->s) || |
| 183 | BN_is_negative(sig->s) || BN_ucmp(sig->s, order) >= 0) { |
| 184 | OPENSSL_PUT_ERROR(ECDSA, ECDSA_do_verify, ECDSA_R_BAD_SIGNATURE); |
| 185 | ret = 0; /* signature is invalid */ |
| 186 | goto err; |
| 187 | } |
| 188 | /* calculate tmp1 = inv(S) mod order */ |
| 189 | if (!BN_mod_inverse(u2, sig->s, order, ctx)) { |
| 190 | OPENSSL_PUT_ERROR(ECDSA, ECDSA_do_verify, ERR_R_BN_LIB); |
| 191 | goto err; |
| 192 | } |
| 193 | if (!digest_to_bn(m, digest, digest_len, order)) { |
| 194 | goto err; |
| 195 | } |
| 196 | /* u1 = m * tmp mod order */ |
| 197 | if (!BN_mod_mul(u1, m, u2, order, ctx)) { |
| 198 | OPENSSL_PUT_ERROR(ECDSA, ECDSA_do_verify, ERR_R_BN_LIB); |
| 199 | goto err; |
| 200 | } |
| 201 | /* u2 = r * w mod q */ |
| 202 | if (!BN_mod_mul(u2, sig->r, u2, order, ctx)) { |
| 203 | OPENSSL_PUT_ERROR(ECDSA, ECDSA_do_verify, ERR_R_BN_LIB); |
| 204 | goto err; |
| 205 | } |
| 206 | |
| 207 | point = EC_POINT_new(group); |
| 208 | if (point == NULL) { |
| 209 | OPENSSL_PUT_ERROR(ECDSA, ECDSA_do_verify, ERR_R_MALLOC_FAILURE); |
| 210 | goto err; |
| 211 | } |
| 212 | if (!EC_POINT_mul(group, point, u1, pub_key, u2, ctx)) { |
| 213 | OPENSSL_PUT_ERROR(ECDSA, ECDSA_do_verify, ERR_R_EC_LIB); |
| 214 | goto err; |
| 215 | } |
| 216 | if (!EC_POINT_get_affine_coordinates_GFp(group, point, X, NULL, ctx)) { |
| 217 | OPENSSL_PUT_ERROR(ECDSA, ECDSA_do_verify, ERR_R_EC_LIB); |
| 218 | goto err; |
| 219 | } |
| 220 | if (!BN_nnmod(u1, X, order, ctx)) { |
| 221 | OPENSSL_PUT_ERROR(ECDSA, ECDSA_do_verify, ERR_R_BN_LIB); |
| 222 | goto err; |
| 223 | } |
| 224 | /* if the signature is correct u1 is equal to sig->r */ |
| 225 | ret = (BN_ucmp(u1, sig->r) == 0); |
| 226 | |
| 227 | err: |
| 228 | BN_CTX_end(ctx); |
| 229 | BN_CTX_free(ctx); |
Adam Langley | e9ada86 | 2015-05-11 17:20:37 -0700 | [diff] [blame^] | 230 | EC_POINT_free(point); |
Adam Langley | d9e397b | 2015-01-22 14:27:53 -0800 | [diff] [blame] | 231 | return ret; |
| 232 | } |
| 233 | |
| 234 | static int ecdsa_sign_setup(EC_KEY *eckey, BN_CTX *ctx_in, BIGNUM **kinvp, |
| 235 | BIGNUM **rp, const uint8_t *digest, |
| 236 | size_t digest_len) { |
| 237 | BN_CTX *ctx = NULL; |
| 238 | BIGNUM *k = NULL, *r = NULL, *order = NULL, *X = NULL; |
| 239 | EC_POINT *tmp_point = NULL; |
| 240 | const EC_GROUP *group; |
| 241 | int ret = 0; |
| 242 | |
| 243 | if (eckey == NULL || (group = EC_KEY_get0_group(eckey)) == NULL) { |
| 244 | OPENSSL_PUT_ERROR(ECDSA, ecdsa_sign_setup, ERR_R_PASSED_NULL_PARAMETER); |
| 245 | return 0; |
| 246 | } |
| 247 | |
| 248 | if (ctx_in == NULL) { |
| 249 | if ((ctx = BN_CTX_new()) == NULL) { |
| 250 | OPENSSL_PUT_ERROR(ECDSA, ecdsa_sign_setup, ERR_R_MALLOC_FAILURE); |
| 251 | return 0; |
| 252 | } |
| 253 | } else { |
| 254 | ctx = ctx_in; |
| 255 | } |
| 256 | |
| 257 | k = BN_new(); /* this value is later returned in *kinvp */ |
| 258 | r = BN_new(); /* this value is later returned in *rp */ |
| 259 | order = BN_new(); |
| 260 | X = BN_new(); |
| 261 | if (!k || !r || !order || !X) { |
| 262 | OPENSSL_PUT_ERROR(ECDSA, ecdsa_sign_setup, ERR_R_MALLOC_FAILURE); |
| 263 | goto err; |
| 264 | } |
| 265 | tmp_point = EC_POINT_new(group); |
| 266 | if (tmp_point == NULL) { |
| 267 | OPENSSL_PUT_ERROR(ECDSA, ecdsa_sign_setup, ERR_R_EC_LIB); |
| 268 | goto err; |
| 269 | } |
| 270 | if (!EC_GROUP_get_order(group, order, ctx)) { |
| 271 | OPENSSL_PUT_ERROR(ECDSA, ecdsa_sign_setup, ERR_R_EC_LIB); |
| 272 | goto err; |
| 273 | } |
| 274 | |
| 275 | do { |
| 276 | /* If possible, we'll include the private key and message digest in the k |
| 277 | * generation. The |digest| argument is only empty if |ECDSA_sign_setup| is |
| 278 | * being used. */ |
| 279 | do { |
| 280 | int ok; |
| 281 | |
| 282 | if (digest_len > 0) { |
| 283 | ok = BN_generate_dsa_nonce(k, order, EC_KEY_get0_private_key(eckey), |
| 284 | digest, digest_len, ctx); |
| 285 | } else { |
| 286 | ok = BN_rand_range(k, order); |
| 287 | } |
| 288 | if (!ok) { |
| 289 | OPENSSL_PUT_ERROR(ECDSA, ecdsa_sign_setup, |
| 290 | ECDSA_R_RANDOM_NUMBER_GENERATION_FAILED); |
| 291 | goto err; |
| 292 | } |
| 293 | } while (BN_is_zero(k)); |
| 294 | |
| 295 | /* We do not want timing information to leak the length of k, |
| 296 | * so we compute G*k using an equivalent scalar of fixed |
| 297 | * bit-length. */ |
| 298 | |
| 299 | if (!BN_add(k, k, order)) { |
| 300 | goto err; |
| 301 | } |
| 302 | if (BN_num_bits(k) <= BN_num_bits(order)) { |
| 303 | if (!BN_add(k, k, order)) { |
| 304 | goto err; |
| 305 | } |
| 306 | } |
| 307 | |
| 308 | /* compute r the x-coordinate of generator * k */ |
| 309 | if (!EC_POINT_mul(group, tmp_point, k, NULL, NULL, ctx)) { |
| 310 | OPENSSL_PUT_ERROR(ECDSA, ecdsa_sign_setup, ERR_R_EC_LIB); |
| 311 | goto err; |
| 312 | } |
| 313 | if (!EC_POINT_get_affine_coordinates_GFp(group, tmp_point, X, NULL, ctx)) { |
| 314 | OPENSSL_PUT_ERROR(ECDSA, ecdsa_sign_setup, ERR_R_EC_LIB); |
| 315 | goto err; |
| 316 | } |
| 317 | |
| 318 | if (!BN_nnmod(r, X, order, ctx)) { |
| 319 | OPENSSL_PUT_ERROR(ECDSA, ecdsa_sign_setup, ERR_R_BN_LIB); |
| 320 | goto err; |
| 321 | } |
| 322 | } while (BN_is_zero(r)); |
| 323 | |
| 324 | /* compute the inverse of k */ |
| 325 | if (!BN_mod_inverse(k, k, order, ctx)) { |
| 326 | OPENSSL_PUT_ERROR(ECDSA, ecdsa_sign_setup, ERR_R_BN_LIB); |
| 327 | goto err; |
| 328 | } |
| 329 | /* clear old values if necessary */ |
Adam Langley | e9ada86 | 2015-05-11 17:20:37 -0700 | [diff] [blame^] | 330 | BN_clear_free(*rp); |
| 331 | BN_clear_free(*kinvp); |
Adam Langley | d9e397b | 2015-01-22 14:27:53 -0800 | [diff] [blame] | 332 | |
| 333 | /* save the pre-computed values */ |
| 334 | *rp = r; |
| 335 | *kinvp = k; |
| 336 | ret = 1; |
| 337 | |
| 338 | err: |
| 339 | if (!ret) { |
Adam Langley | e9ada86 | 2015-05-11 17:20:37 -0700 | [diff] [blame^] | 340 | BN_clear_free(k); |
| 341 | BN_clear_free(r); |
Adam Langley | d9e397b | 2015-01-22 14:27:53 -0800 | [diff] [blame] | 342 | } |
Adam Langley | e9ada86 | 2015-05-11 17:20:37 -0700 | [diff] [blame^] | 343 | if (ctx_in == NULL) { |
Adam Langley | d9e397b | 2015-01-22 14:27:53 -0800 | [diff] [blame] | 344 | BN_CTX_free(ctx); |
Adam Langley | e9ada86 | 2015-05-11 17:20:37 -0700 | [diff] [blame^] | 345 | } |
| 346 | BN_free(order); |
| 347 | EC_POINT_free(tmp_point); |
| 348 | BN_clear_free(X); |
Adam Langley | d9e397b | 2015-01-22 14:27:53 -0800 | [diff] [blame] | 349 | return ret; |
| 350 | } |
| 351 | |
| 352 | int ECDSA_sign_setup(EC_KEY *eckey, BN_CTX *ctx, BIGNUM **kinv, BIGNUM **rp) { |
| 353 | return ecdsa_sign_setup(eckey, ctx, kinv, rp, NULL, 0); |
| 354 | } |
| 355 | |
| 356 | ECDSA_SIG *ECDSA_do_sign_ex(const uint8_t *digest, size_t digest_len, |
| 357 | const BIGNUM *in_kinv, const BIGNUM *in_r, |
| 358 | EC_KEY *eckey) { |
| 359 | int ok = 0; |
| 360 | BIGNUM *kinv = NULL, *s, *m = NULL, *tmp = NULL, *order = NULL; |
| 361 | const BIGNUM *ckinv; |
| 362 | BN_CTX *ctx = NULL; |
| 363 | const EC_GROUP *group; |
| 364 | ECDSA_SIG *ret; |
| 365 | const BIGNUM *priv_key; |
| 366 | |
| 367 | if (eckey->ecdsa_meth && eckey->ecdsa_meth->sign) { |
| 368 | OPENSSL_PUT_ERROR(ECDSA, ECDSA_do_sign_ex, ECDSA_R_NOT_IMPLEMENTED); |
| 369 | return NULL; |
| 370 | } |
| 371 | |
| 372 | group = EC_KEY_get0_group(eckey); |
| 373 | priv_key = EC_KEY_get0_private_key(eckey); |
| 374 | |
| 375 | if (group == NULL || priv_key == NULL) { |
| 376 | OPENSSL_PUT_ERROR(ECDSA, ECDSA_do_sign_ex, ERR_R_PASSED_NULL_PARAMETER); |
| 377 | return NULL; |
| 378 | } |
| 379 | |
| 380 | ret = ECDSA_SIG_new(); |
| 381 | if (!ret) { |
| 382 | OPENSSL_PUT_ERROR(ECDSA, ECDSA_do_sign_ex, ERR_R_MALLOC_FAILURE); |
| 383 | return NULL; |
| 384 | } |
| 385 | s = ret->s; |
| 386 | |
| 387 | if ((ctx = BN_CTX_new()) == NULL || (order = BN_new()) == NULL || |
| 388 | (tmp = BN_new()) == NULL || (m = BN_new()) == NULL) { |
| 389 | OPENSSL_PUT_ERROR(ECDSA, ECDSA_do_sign_ex, ERR_R_MALLOC_FAILURE); |
| 390 | goto err; |
| 391 | } |
| 392 | |
| 393 | if (!EC_GROUP_get_order(group, order, ctx)) { |
| 394 | OPENSSL_PUT_ERROR(ECDSA, ECDSA_do_sign_ex, ERR_R_EC_LIB); |
| 395 | goto err; |
| 396 | } |
| 397 | if (!digest_to_bn(m, digest, digest_len, order)) { |
| 398 | goto err; |
| 399 | } |
| 400 | for (;;) { |
| 401 | if (in_kinv == NULL || in_r == NULL) { |
| 402 | if (!ecdsa_sign_setup(eckey, ctx, &kinv, &ret->r, digest, digest_len)) { |
| 403 | OPENSSL_PUT_ERROR(ECDSA, ECDSA_do_sign_ex, ERR_R_ECDSA_LIB); |
| 404 | goto err; |
| 405 | } |
| 406 | ckinv = kinv; |
| 407 | } else { |
| 408 | ckinv = in_kinv; |
| 409 | if (BN_copy(ret->r, in_r) == NULL) { |
| 410 | OPENSSL_PUT_ERROR(ECDSA, ECDSA_do_sign_ex, ERR_R_MALLOC_FAILURE); |
| 411 | goto err; |
| 412 | } |
| 413 | } |
| 414 | |
| 415 | if (!BN_mod_mul(tmp, priv_key, ret->r, order, ctx)) { |
| 416 | OPENSSL_PUT_ERROR(ECDSA, ECDSA_do_sign_ex, ERR_R_BN_LIB); |
| 417 | goto err; |
| 418 | } |
| 419 | if (!BN_mod_add_quick(s, tmp, m, order)) { |
| 420 | OPENSSL_PUT_ERROR(ECDSA, ECDSA_do_sign_ex, ERR_R_BN_LIB); |
| 421 | goto err; |
| 422 | } |
| 423 | if (!BN_mod_mul(s, s, ckinv, order, ctx)) { |
| 424 | OPENSSL_PUT_ERROR(ECDSA, ECDSA_do_sign_ex, ERR_R_BN_LIB); |
| 425 | goto err; |
| 426 | } |
| 427 | if (BN_is_zero(s)) { |
| 428 | /* if kinv and r have been supplied by the caller |
| 429 | * don't to generate new kinv and r values */ |
| 430 | if (in_kinv != NULL && in_r != NULL) { |
| 431 | OPENSSL_PUT_ERROR(ECDSA, ECDSA_do_sign_ex, ECDSA_R_NEED_NEW_SETUP_VALUES); |
| 432 | goto err; |
| 433 | } |
| 434 | } else { |
| 435 | /* s != 0 => we have a valid signature */ |
| 436 | break; |
| 437 | } |
| 438 | } |
| 439 | |
| 440 | ok = 1; |
| 441 | |
| 442 | err: |
| 443 | if (!ok) { |
| 444 | ECDSA_SIG_free(ret); |
| 445 | ret = NULL; |
| 446 | } |
Adam Langley | e9ada86 | 2015-05-11 17:20:37 -0700 | [diff] [blame^] | 447 | BN_CTX_free(ctx); |
| 448 | BN_clear_free(m); |
| 449 | BN_clear_free(tmp); |
| 450 | BN_free(order); |
| 451 | BN_clear_free(kinv); |
Adam Langley | d9e397b | 2015-01-22 14:27:53 -0800 | [diff] [blame] | 452 | return ret; |
| 453 | } |
| 454 | |
| 455 | int ECDSA_sign_ex(int type, const uint8_t *digest, size_t digest_len, |
| 456 | uint8_t *sig, unsigned int *sig_len, const BIGNUM *kinv, |
| 457 | const BIGNUM *r, EC_KEY *eckey) { |
| 458 | ECDSA_SIG *s = NULL; |
| 459 | |
| 460 | if (eckey->ecdsa_meth && eckey->ecdsa_meth->sign) { |
| 461 | OPENSSL_PUT_ERROR(ECDSA, ECDSA_sign_ex, ECDSA_R_NOT_IMPLEMENTED); |
| 462 | *sig_len = 0; |
| 463 | return 0; |
| 464 | } |
| 465 | |
| 466 | s = ECDSA_do_sign_ex(digest, digest_len, kinv, r, eckey); |
| 467 | if (s == NULL) { |
| 468 | *sig_len = 0; |
| 469 | return 0; |
| 470 | } |
| 471 | *sig_len = i2d_ECDSA_SIG(s, &sig); |
| 472 | ECDSA_SIG_free(s); |
| 473 | return 1; |
| 474 | } |