1160814Ssimon/* crypto/ecdsa/ecs_ossl.c */ 2160814Ssimon/* 3160814Ssimon * Written by Nils Larsch for the OpenSSL project 4160814Ssimon */ 5160814Ssimon/* ==================================================================== 6160814Ssimon * Copyright (c) 1998-2004 The OpenSSL Project. All rights reserved. 7160814Ssimon * 8160814Ssimon * Redistribution and use in source and binary forms, with or without 9160814Ssimon * modification, are permitted provided that the following conditions 10160814Ssimon * are met: 11160814Ssimon * 12160814Ssimon * 1. Redistributions of source code must retain the above copyright 13296341Sdelphij * notice, this list of conditions and the following disclaimer. 14160814Ssimon * 15160814Ssimon * 2. Redistributions in binary form must reproduce the above copyright 16160814Ssimon * notice, this list of conditions and the following disclaimer in 17160814Ssimon * the documentation and/or other materials provided with the 18160814Ssimon * distribution. 19160814Ssimon * 20160814Ssimon * 3. All advertising materials mentioning features or use of this 21160814Ssimon * software must display the following acknowledgment: 22160814Ssimon * "This product includes software developed by the OpenSSL Project 23160814Ssimon * for use in the OpenSSL Toolkit. (http://www.OpenSSL.org/)" 24160814Ssimon * 25160814Ssimon * 4. The names "OpenSSL Toolkit" and "OpenSSL Project" must not be used to 26160814Ssimon * endorse or promote products derived from this software without 27160814Ssimon * prior written permission. For written permission, please contact 28160814Ssimon * openssl-core@OpenSSL.org. 29160814Ssimon * 30160814Ssimon * 5. Products derived from this software may not be called "OpenSSL" 31160814Ssimon * nor may "OpenSSL" appear in their names without prior written 32160814Ssimon * permission of the OpenSSL Project. 33160814Ssimon * 34160814Ssimon * 6. Redistributions of any form whatsoever must retain the following 35160814Ssimon * acknowledgment: 36160814Ssimon * "This product includes software developed by the OpenSSL Project 37160814Ssimon * for use in the OpenSSL Toolkit (http://www.OpenSSL.org/)" 38160814Ssimon * 39160814Ssimon * THIS SOFTWARE IS PROVIDED BY THE OpenSSL PROJECT ``AS IS'' AND ANY 40160814Ssimon * EXPRESSED OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 41160814Ssimon * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR 42160814Ssimon * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE OpenSSL PROJECT OR 43160814Ssimon * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, 44160814Ssimon * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT 45160814Ssimon * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; 46160814Ssimon * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 47160814Ssimon * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, 48160814Ssimon * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) 49160814Ssimon * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED 50160814Ssimon * OF THE POSSIBILITY OF SUCH DAMAGE. 51160814Ssimon * ==================================================================== 52160814Ssimon * 53160814Ssimon * This product includes cryptographic software written by Eric Young 54160814Ssimon * (eay@cryptsoft.com). This product includes software written by Tim 55160814Ssimon * Hudson (tjh@cryptsoft.com). 56160814Ssimon * 57160814Ssimon */ 58160814Ssimon 59160814Ssimon#include "ecs_locl.h" 60160814Ssimon#include <openssl/err.h> 61160814Ssimon#include <openssl/obj_mac.h> 62160814Ssimon#include <openssl/bn.h> 63160814Ssimon 64296341Sdelphijstatic ECDSA_SIG *ecdsa_do_sign(const unsigned char *dgst, int dlen, 65296341Sdelphij const BIGNUM *, const BIGNUM *, 66296341Sdelphij EC_KEY *eckey); 67296341Sdelphijstatic int ecdsa_sign_setup(EC_KEY *eckey, BN_CTX *ctx_in, BIGNUM **kinvp, 68296341Sdelphij BIGNUM **rp); 69296341Sdelphijstatic int ecdsa_do_verify(const unsigned char *dgst, int dgst_len, 70296341Sdelphij const ECDSA_SIG *sig, EC_KEY *eckey); 71160814Ssimon 72160814Ssimonstatic ECDSA_METHOD openssl_ecdsa_meth = { 73296341Sdelphij "OpenSSL ECDSA method", 74296341Sdelphij ecdsa_do_sign, 75296341Sdelphij ecdsa_sign_setup, 76296341Sdelphij ecdsa_do_verify, 77160814Ssimon#if 0 78296341Sdelphij NULL, /* init */ 79296341Sdelphij NULL, /* finish */ 80160814Ssimon#endif 81296341Sdelphij 0, /* flags */ 82296341Sdelphij NULL /* app_data */ 83160814Ssimon}; 84160814Ssimon 85160814Ssimonconst ECDSA_METHOD *ECDSA_OpenSSL(void) 86160814Ssimon{ 87296341Sdelphij return &openssl_ecdsa_meth; 88160814Ssimon} 89160814Ssimon 90160814Ssimonstatic int ecdsa_sign_setup(EC_KEY *eckey, BN_CTX *ctx_in, BIGNUM **kinvp, 91296341Sdelphij BIGNUM **rp) 92160814Ssimon{ 93296341Sdelphij BN_CTX *ctx = NULL; 94296341Sdelphij BIGNUM *k = NULL, *r = NULL, *order = NULL, *X = NULL; 95296341Sdelphij EC_POINT *tmp_point = NULL; 96296341Sdelphij const EC_GROUP *group; 97296341Sdelphij int ret = 0; 98160814Ssimon 99296341Sdelphij if (eckey == NULL || (group = EC_KEY_get0_group(eckey)) == NULL) { 100296341Sdelphij ECDSAerr(ECDSA_F_ECDSA_SIGN_SETUP, ERR_R_PASSED_NULL_PARAMETER); 101296341Sdelphij return 0; 102296341Sdelphij } 103160814Ssimon 104296341Sdelphij if (ctx_in == NULL) { 105296341Sdelphij if ((ctx = BN_CTX_new()) == NULL) { 106296341Sdelphij ECDSAerr(ECDSA_F_ECDSA_SIGN_SETUP, ERR_R_MALLOC_FAILURE); 107296341Sdelphij return 0; 108296341Sdelphij } 109296341Sdelphij } else 110296341Sdelphij ctx = ctx_in; 111160814Ssimon 112296341Sdelphij k = BN_new(); /* this value is later returned in *kinvp */ 113296341Sdelphij r = BN_new(); /* this value is later returned in *rp */ 114296341Sdelphij order = BN_new(); 115296341Sdelphij X = BN_new(); 116296341Sdelphij if (!k || !r || !order || !X) { 117296341Sdelphij ECDSAerr(ECDSA_F_ECDSA_SIGN_SETUP, ERR_R_MALLOC_FAILURE); 118296341Sdelphij goto err; 119296341Sdelphij } 120296341Sdelphij if ((tmp_point = EC_POINT_new(group)) == NULL) { 121296341Sdelphij ECDSAerr(ECDSA_F_ECDSA_SIGN_SETUP, ERR_R_EC_LIB); 122296341Sdelphij goto err; 123296341Sdelphij } 124296341Sdelphij if (!EC_GROUP_get_order(group, order, ctx)) { 125296341Sdelphij ECDSAerr(ECDSA_F_ECDSA_SIGN_SETUP, ERR_R_EC_LIB); 126296341Sdelphij goto err; 127296341Sdelphij } 128160814Ssimon 129296341Sdelphij do { 130296341Sdelphij /* get random k */ 131296341Sdelphij do 132296341Sdelphij if (!BN_rand_range(k, order)) { 133296341Sdelphij ECDSAerr(ECDSA_F_ECDSA_SIGN_SETUP, 134296341Sdelphij ECDSA_R_RANDOM_NUMBER_GENERATION_FAILED); 135296341Sdelphij goto err; 136296341Sdelphij } 137296341Sdelphij while (BN_is_zero(k)) ; 138237657Sjkim 139296341Sdelphij /* 140296341Sdelphij * We do not want timing information to leak the length of k, so we 141296341Sdelphij * compute G*k using an equivalent scalar of fixed bit-length. 142296341Sdelphij */ 143237657Sjkim 144296341Sdelphij if (!BN_add(k, k, order)) 145296341Sdelphij goto err; 146296341Sdelphij if (BN_num_bits(k) <= BN_num_bits(order)) 147296341Sdelphij if (!BN_add(k, k, order)) 148296341Sdelphij goto err; 149296341Sdelphij 150296341Sdelphij /* compute r the x-coordinate of generator * k */ 151296341Sdelphij if (!EC_POINT_mul(group, tmp_point, k, NULL, NULL, ctx)) { 152296341Sdelphij ECDSAerr(ECDSA_F_ECDSA_SIGN_SETUP, ERR_R_EC_LIB); 153296341Sdelphij goto err; 154296341Sdelphij } 155296341Sdelphij if (EC_METHOD_get_field_type(EC_GROUP_method_of(group)) == 156296341Sdelphij NID_X9_62_prime_field) { 157296341Sdelphij if (!EC_POINT_get_affine_coordinates_GFp 158296341Sdelphij (group, tmp_point, X, NULL, ctx)) { 159296341Sdelphij ECDSAerr(ECDSA_F_ECDSA_SIGN_SETUP, ERR_R_EC_LIB); 160296341Sdelphij goto err; 161296341Sdelphij } 162296341Sdelphij } 163238405Sjkim#ifndef OPENSSL_NO_EC2M 164296341Sdelphij else { /* NID_X9_62_characteristic_two_field */ 165296341Sdelphij 166296341Sdelphij if (!EC_POINT_get_affine_coordinates_GF2m(group, 167296341Sdelphij tmp_point, X, NULL, 168296341Sdelphij ctx)) { 169296341Sdelphij ECDSAerr(ECDSA_F_ECDSA_SIGN_SETUP, ERR_R_EC_LIB); 170296341Sdelphij goto err; 171296341Sdelphij } 172296341Sdelphij } 173238405Sjkim#endif 174296341Sdelphij if (!BN_nnmod(r, X, order, ctx)) { 175296341Sdelphij ECDSAerr(ECDSA_F_ECDSA_SIGN_SETUP, ERR_R_BN_LIB); 176296341Sdelphij goto err; 177296341Sdelphij } 178296341Sdelphij } 179296341Sdelphij while (BN_is_zero(r)); 180160814Ssimon 181296341Sdelphij /* compute the inverse of k */ 182296341Sdelphij if (!BN_mod_inverse(k, k, order, ctx)) { 183296341Sdelphij ECDSAerr(ECDSA_F_ECDSA_SIGN_SETUP, ERR_R_BN_LIB); 184296341Sdelphij goto err; 185296341Sdelphij } 186296341Sdelphij /* clear old values if necessary */ 187296341Sdelphij if (*rp != NULL) 188296341Sdelphij BN_clear_free(*rp); 189296341Sdelphij if (*kinvp != NULL) 190296341Sdelphij BN_clear_free(*kinvp); 191296341Sdelphij /* save the pre-computed values */ 192296341Sdelphij *rp = r; 193296341Sdelphij *kinvp = k; 194296341Sdelphij ret = 1; 195296341Sdelphij err: 196296341Sdelphij if (!ret) { 197296341Sdelphij if (k != NULL) 198296341Sdelphij BN_clear_free(k); 199296341Sdelphij if (r != NULL) 200296341Sdelphij BN_clear_free(r); 201296341Sdelphij } 202296341Sdelphij if (ctx_in == NULL) 203296341Sdelphij BN_CTX_free(ctx); 204296341Sdelphij if (order != NULL) 205296341Sdelphij BN_free(order); 206296341Sdelphij if (tmp_point != NULL) 207296341Sdelphij EC_POINT_free(tmp_point); 208296341Sdelphij if (X) 209296341Sdelphij BN_clear_free(X); 210296341Sdelphij return (ret); 211160814Ssimon} 212160814Ssimon 213296341Sdelphijstatic ECDSA_SIG *ecdsa_do_sign(const unsigned char *dgst, int dgst_len, 214296341Sdelphij const BIGNUM *in_kinv, const BIGNUM *in_r, 215296341Sdelphij EC_KEY *eckey) 216160814Ssimon{ 217296341Sdelphij int ok = 0, i; 218296341Sdelphij BIGNUM *kinv = NULL, *s, *m = NULL, *tmp = NULL, *order = NULL; 219296341Sdelphij const BIGNUM *ckinv; 220296341Sdelphij BN_CTX *ctx = NULL; 221296341Sdelphij const EC_GROUP *group; 222296341Sdelphij ECDSA_SIG *ret; 223296341Sdelphij ECDSA_DATA *ecdsa; 224296341Sdelphij const BIGNUM *priv_key; 225160814Ssimon 226296341Sdelphij ecdsa = ecdsa_check(eckey); 227296341Sdelphij group = EC_KEY_get0_group(eckey); 228296341Sdelphij priv_key = EC_KEY_get0_private_key(eckey); 229160814Ssimon 230296341Sdelphij if (group == NULL || priv_key == NULL || ecdsa == NULL) { 231296341Sdelphij ECDSAerr(ECDSA_F_ECDSA_DO_SIGN, ERR_R_PASSED_NULL_PARAMETER); 232296341Sdelphij return NULL; 233296341Sdelphij } 234160814Ssimon 235296341Sdelphij ret = ECDSA_SIG_new(); 236296341Sdelphij if (!ret) { 237296341Sdelphij ECDSAerr(ECDSA_F_ECDSA_DO_SIGN, ERR_R_MALLOC_FAILURE); 238296341Sdelphij return NULL; 239296341Sdelphij } 240296341Sdelphij s = ret->s; 241160814Ssimon 242296341Sdelphij if ((ctx = BN_CTX_new()) == NULL || (order = BN_new()) == NULL || 243296341Sdelphij (tmp = BN_new()) == NULL || (m = BN_new()) == NULL) { 244296341Sdelphij ECDSAerr(ECDSA_F_ECDSA_DO_SIGN, ERR_R_MALLOC_FAILURE); 245296341Sdelphij goto err; 246296341Sdelphij } 247160814Ssimon 248296341Sdelphij if (!EC_GROUP_get_order(group, order, ctx)) { 249296341Sdelphij ECDSAerr(ECDSA_F_ECDSA_DO_SIGN, ERR_R_EC_LIB); 250296341Sdelphij goto err; 251296341Sdelphij } 252296341Sdelphij i = BN_num_bits(order); 253296341Sdelphij /* 254296341Sdelphij * Need to truncate digest if it is too long: first truncate whole bytes. 255296341Sdelphij */ 256296341Sdelphij if (8 * dgst_len > i) 257296341Sdelphij dgst_len = (i + 7) / 8; 258296341Sdelphij if (!BN_bin2bn(dgst, dgst_len, m)) { 259296341Sdelphij ECDSAerr(ECDSA_F_ECDSA_DO_SIGN, ERR_R_BN_LIB); 260296341Sdelphij goto err; 261296341Sdelphij } 262296341Sdelphij /* If still too long truncate remaining bits with a shift */ 263296341Sdelphij if ((8 * dgst_len > i) && !BN_rshift(m, m, 8 - (i & 0x7))) { 264296341Sdelphij ECDSAerr(ECDSA_F_ECDSA_DO_SIGN, ERR_R_BN_LIB); 265296341Sdelphij goto err; 266296341Sdelphij } 267296341Sdelphij do { 268296341Sdelphij if (in_kinv == NULL || in_r == NULL) { 269296341Sdelphij if (!ECDSA_sign_setup(eckey, ctx, &kinv, &ret->r)) { 270296341Sdelphij ECDSAerr(ECDSA_F_ECDSA_DO_SIGN, ERR_R_ECDSA_LIB); 271296341Sdelphij goto err; 272296341Sdelphij } 273296341Sdelphij ckinv = kinv; 274296341Sdelphij } else { 275296341Sdelphij ckinv = in_kinv; 276296341Sdelphij if (BN_copy(ret->r, in_r) == NULL) { 277296341Sdelphij ECDSAerr(ECDSA_F_ECDSA_DO_SIGN, ERR_R_MALLOC_FAILURE); 278296341Sdelphij goto err; 279296341Sdelphij } 280296341Sdelphij } 281160814Ssimon 282296341Sdelphij if (!BN_mod_mul(tmp, priv_key, ret->r, order, ctx)) { 283296341Sdelphij ECDSAerr(ECDSA_F_ECDSA_DO_SIGN, ERR_R_BN_LIB); 284296341Sdelphij goto err; 285296341Sdelphij } 286296341Sdelphij if (!BN_mod_add_quick(s, tmp, m, order)) { 287296341Sdelphij ECDSAerr(ECDSA_F_ECDSA_DO_SIGN, ERR_R_BN_LIB); 288296341Sdelphij goto err; 289296341Sdelphij } 290296341Sdelphij if (!BN_mod_mul(s, s, ckinv, order, ctx)) { 291296341Sdelphij ECDSAerr(ECDSA_F_ECDSA_DO_SIGN, ERR_R_BN_LIB); 292296341Sdelphij goto err; 293296341Sdelphij } 294296341Sdelphij if (BN_is_zero(s)) { 295296341Sdelphij /* 296296341Sdelphij * if kinv and r have been supplied by the caller don't to 297296341Sdelphij * generate new kinv and r values 298296341Sdelphij */ 299296341Sdelphij if (in_kinv != NULL && in_r != NULL) { 300296341Sdelphij ECDSAerr(ECDSA_F_ECDSA_DO_SIGN, 301296341Sdelphij ECDSA_R_NEED_NEW_SETUP_VALUES); 302296341Sdelphij goto err; 303296341Sdelphij } 304296341Sdelphij } else 305296341Sdelphij /* s != 0 => we have a valid signature */ 306296341Sdelphij break; 307296341Sdelphij } 308296341Sdelphij while (1); 309296341Sdelphij 310296341Sdelphij ok = 1; 311296341Sdelphij err: 312296341Sdelphij if (!ok) { 313296341Sdelphij ECDSA_SIG_free(ret); 314296341Sdelphij ret = NULL; 315296341Sdelphij } 316296341Sdelphij if (ctx) 317296341Sdelphij BN_CTX_free(ctx); 318296341Sdelphij if (m) 319296341Sdelphij BN_clear_free(m); 320296341Sdelphij if (tmp) 321296341Sdelphij BN_clear_free(tmp); 322296341Sdelphij if (order) 323296341Sdelphij BN_free(order); 324296341Sdelphij if (kinv) 325296341Sdelphij BN_clear_free(kinv); 326296341Sdelphij return ret; 327160814Ssimon} 328160814Ssimon 329160814Ssimonstatic int ecdsa_do_verify(const unsigned char *dgst, int dgst_len, 330296341Sdelphij const ECDSA_SIG *sig, EC_KEY *eckey) 331160814Ssimon{ 332296341Sdelphij int ret = -1, i; 333296341Sdelphij BN_CTX *ctx; 334296341Sdelphij BIGNUM *order, *u1, *u2, *m, *X; 335296341Sdelphij EC_POINT *point = NULL; 336296341Sdelphij const EC_GROUP *group; 337296341Sdelphij const EC_POINT *pub_key; 338160814Ssimon 339296341Sdelphij /* check input values */ 340296341Sdelphij if (eckey == NULL || (group = EC_KEY_get0_group(eckey)) == NULL || 341296341Sdelphij (pub_key = EC_KEY_get0_public_key(eckey)) == NULL || sig == NULL) { 342296341Sdelphij ECDSAerr(ECDSA_F_ECDSA_DO_VERIFY, ECDSA_R_MISSING_PARAMETERS); 343296341Sdelphij return -1; 344296341Sdelphij } 345160814Ssimon 346296341Sdelphij ctx = BN_CTX_new(); 347296341Sdelphij if (!ctx) { 348296341Sdelphij ECDSAerr(ECDSA_F_ECDSA_DO_VERIFY, ERR_R_MALLOC_FAILURE); 349296341Sdelphij return -1; 350296341Sdelphij } 351296341Sdelphij BN_CTX_start(ctx); 352296341Sdelphij order = BN_CTX_get(ctx); 353296341Sdelphij u1 = BN_CTX_get(ctx); 354296341Sdelphij u2 = BN_CTX_get(ctx); 355296341Sdelphij m = BN_CTX_get(ctx); 356296341Sdelphij X = BN_CTX_get(ctx); 357296341Sdelphij if (!X) { 358296341Sdelphij ECDSAerr(ECDSA_F_ECDSA_DO_VERIFY, ERR_R_BN_LIB); 359296341Sdelphij goto err; 360296341Sdelphij } 361160814Ssimon 362296341Sdelphij if (!EC_GROUP_get_order(group, order, ctx)) { 363296341Sdelphij ECDSAerr(ECDSA_F_ECDSA_DO_VERIFY, ERR_R_EC_LIB); 364296341Sdelphij goto err; 365296341Sdelphij } 366160814Ssimon 367296341Sdelphij if (BN_is_zero(sig->r) || BN_is_negative(sig->r) || 368296341Sdelphij BN_ucmp(sig->r, order) >= 0 || BN_is_zero(sig->s) || 369296341Sdelphij BN_is_negative(sig->s) || BN_ucmp(sig->s, order) >= 0) { 370296341Sdelphij ECDSAerr(ECDSA_F_ECDSA_DO_VERIFY, ECDSA_R_BAD_SIGNATURE); 371296341Sdelphij ret = 0; /* signature is invalid */ 372296341Sdelphij goto err; 373296341Sdelphij } 374296341Sdelphij /* calculate tmp1 = inv(S) mod order */ 375296341Sdelphij if (!BN_mod_inverse(u2, sig->s, order, ctx)) { 376296341Sdelphij ECDSAerr(ECDSA_F_ECDSA_DO_VERIFY, ERR_R_BN_LIB); 377296341Sdelphij goto err; 378296341Sdelphij } 379296341Sdelphij /* digest -> m */ 380296341Sdelphij i = BN_num_bits(order); 381296341Sdelphij /* 382296341Sdelphij * Need to truncate digest if it is too long: first truncate whole bytes. 383296341Sdelphij */ 384296341Sdelphij if (8 * dgst_len > i) 385296341Sdelphij dgst_len = (i + 7) / 8; 386296341Sdelphij if (!BN_bin2bn(dgst, dgst_len, m)) { 387296341Sdelphij ECDSAerr(ECDSA_F_ECDSA_DO_VERIFY, ERR_R_BN_LIB); 388296341Sdelphij goto err; 389296341Sdelphij } 390296341Sdelphij /* If still too long truncate remaining bits with a shift */ 391296341Sdelphij if ((8 * dgst_len > i) && !BN_rshift(m, m, 8 - (i & 0x7))) { 392296341Sdelphij ECDSAerr(ECDSA_F_ECDSA_DO_VERIFY, ERR_R_BN_LIB); 393296341Sdelphij goto err; 394296341Sdelphij } 395296341Sdelphij /* u1 = m * tmp mod order */ 396296341Sdelphij if (!BN_mod_mul(u1, m, u2, order, ctx)) { 397296341Sdelphij ECDSAerr(ECDSA_F_ECDSA_DO_VERIFY, ERR_R_BN_LIB); 398296341Sdelphij goto err; 399296341Sdelphij } 400296341Sdelphij /* u2 = r * w mod q */ 401296341Sdelphij if (!BN_mod_mul(u2, sig->r, u2, order, ctx)) { 402296341Sdelphij ECDSAerr(ECDSA_F_ECDSA_DO_VERIFY, ERR_R_BN_LIB); 403296341Sdelphij goto err; 404296341Sdelphij } 405296341Sdelphij 406296341Sdelphij if ((point = EC_POINT_new(group)) == NULL) { 407296341Sdelphij ECDSAerr(ECDSA_F_ECDSA_DO_VERIFY, ERR_R_MALLOC_FAILURE); 408296341Sdelphij goto err; 409296341Sdelphij } 410296341Sdelphij if (!EC_POINT_mul(group, point, u1, pub_key, u2, ctx)) { 411296341Sdelphij ECDSAerr(ECDSA_F_ECDSA_DO_VERIFY, ERR_R_EC_LIB); 412296341Sdelphij goto err; 413296341Sdelphij } 414296341Sdelphij if (EC_METHOD_get_field_type(EC_GROUP_method_of(group)) == 415296341Sdelphij NID_X9_62_prime_field) { 416296341Sdelphij if (!EC_POINT_get_affine_coordinates_GFp(group, point, X, NULL, ctx)) { 417296341Sdelphij ECDSAerr(ECDSA_F_ECDSA_DO_VERIFY, ERR_R_EC_LIB); 418296341Sdelphij goto err; 419296341Sdelphij } 420296341Sdelphij } 421238405Sjkim#ifndef OPENSSL_NO_EC2M 422296341Sdelphij else { /* NID_X9_62_characteristic_two_field */ 423296341Sdelphij 424296341Sdelphij if (!EC_POINT_get_affine_coordinates_GF2m(group, point, X, NULL, ctx)) { 425296341Sdelphij ECDSAerr(ECDSA_F_ECDSA_DO_VERIFY, ERR_R_EC_LIB); 426296341Sdelphij goto err; 427296341Sdelphij } 428296341Sdelphij } 429296341Sdelphij#endif 430296341Sdelphij if (!BN_nnmod(u1, X, order, ctx)) { 431296341Sdelphij ECDSAerr(ECDSA_F_ECDSA_DO_VERIFY, ERR_R_BN_LIB); 432296341Sdelphij goto err; 433296341Sdelphij } 434296341Sdelphij /* if the signature is correct u1 is equal to sig->r */ 435296341Sdelphij ret = (BN_ucmp(u1, sig->r) == 0); 436296341Sdelphij err: 437296341Sdelphij BN_CTX_end(ctx); 438296341Sdelphij BN_CTX_free(ctx); 439296341Sdelphij if (point) 440296341Sdelphij EC_POINT_free(point); 441296341Sdelphij return ret; 442160814Ssimon} 443