1 /* crypto/ecdsa/ecs_ossl.c */
3 * Written by Nils Larsch for the OpenSSL project
5 /* ====================================================================
6 * Copyright (c) 1998-2004 The OpenSSL Project. All rights reserved.
8 * Redistribution and use in source and binary forms, with or without
9 * modification, are permitted provided that the following conditions
12 * 1. Redistributions of source code must retain the above copyright
13 * notice, this list of conditions and the following disclaimer.
15 * 2. Redistributions in binary form must reproduce the above copyright
16 * notice, this list of conditions and the following disclaimer in
17 * the documentation and/or other materials provided with the
20 * 3. All advertising materials mentioning features or use of this
21 * software must display the following acknowledgment:
22 * "This product includes software developed by the OpenSSL Project
23 * for use in the OpenSSL Toolkit. (http://www.OpenSSL.org/)"
25 * 4. The names "OpenSSL Toolkit" and "OpenSSL Project" must not be used to
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27 * prior written permission. For written permission, please contact
28 * openssl-core@OpenSSL.org.
30 * 5. Products derived from this software may not be called "OpenSSL"
31 * nor may "OpenSSL" appear in their names without prior written
32 * permission of the OpenSSL Project.
34 * 6. Redistributions of any form whatsoever must retain the following
36 * "This product includes software developed by the OpenSSL Project
37 * for use in the OpenSSL Toolkit (http://www.OpenSSL.org/)"
39 * THIS SOFTWARE IS PROVIDED BY THE OpenSSL PROJECT ``AS IS'' AND ANY
40 * EXPRESSED OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
41 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
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43 * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
44 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
45 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
46 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
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49 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
50 * OF THE POSSIBILITY OF SUCH DAMAGE.
51 * ====================================================================
53 * This product includes cryptographic software written by Eric Young
54 * (eay@cryptsoft.com). This product includes software written by Tim
55 * Hudson (tjh@cryptsoft.com).
59 #define OPENSSL_FIPSAPI
62 #include <openssl/err.h>
63 #include <openssl/obj_mac.h>
64 #include <openssl/bn.h>
66 static ECDSA_SIG *ecdsa_do_sign(const unsigned char *dgst, int dlen,
67 const BIGNUM *, const BIGNUM *, EC_KEY *eckey);
68 static int ecdsa_sign_setup(EC_KEY *eckey, BN_CTX *ctx_in, BIGNUM **kinvp,
70 static int ecdsa_do_verify(const unsigned char *dgst, int dgst_len,
71 const ECDSA_SIG *sig, EC_KEY *eckey);
73 static ECDSA_METHOD openssl_ecdsa_meth = {
74 "OpenSSL ECDSA method",
82 ECDSA_FLAG_FIPS_METHOD, /* flags */
86 const ECDSA_METHOD *ECDSA_OpenSSL(void)
88 return &openssl_ecdsa_meth;
91 static int ecdsa_sign_setup(EC_KEY *eckey, BN_CTX *ctx_in, BIGNUM **kinvp,
95 BIGNUM *k = NULL, *r = NULL, *order = NULL, *X = NULL;
96 EC_POINT *tmp_point=NULL;
97 const EC_GROUP *group;
100 if (eckey == NULL || (group = EC_KEY_get0_group(eckey)) == NULL)
102 ECDSAerr(ECDSA_F_ECDSA_SIGN_SETUP, ERR_R_PASSED_NULL_PARAMETER);
108 if ((ctx = BN_CTX_new()) == NULL)
110 ECDSAerr(ECDSA_F_ECDSA_SIGN_SETUP,ERR_R_MALLOC_FAILURE);
117 k = BN_new(); /* this value is later returned in *kinvp */
118 r = BN_new(); /* this value is later returned in *rp */
121 if (!k || !r || !order || !X)
123 ECDSAerr(ECDSA_F_ECDSA_SIGN_SETUP, ERR_R_MALLOC_FAILURE);
126 if ((tmp_point = EC_POINT_new(group)) == NULL)
128 ECDSAerr(ECDSA_F_ECDSA_SIGN_SETUP, ERR_R_EC_LIB);
131 if (!EC_GROUP_get_order(group, order, ctx))
133 ECDSAerr(ECDSA_F_ECDSA_SIGN_SETUP, ERR_R_EC_LIB);
138 if (!fips_check_ec_prng(eckey))
146 if (!BN_rand_range(k, order))
148 ECDSAerr(ECDSA_F_ECDSA_SIGN_SETUP,
149 ECDSA_R_RANDOM_NUMBER_GENERATION_FAILED);
152 while (BN_is_zero(k));
154 /* We do not want timing information to leak the length of k,
155 * so we compute G*k using an equivalent scalar of fixed
158 if (!BN_add(k, k, order)) goto err;
159 if (BN_num_bits(k) <= BN_num_bits(order))
160 if (!BN_add(k, k, order)) goto err;
162 /* compute r the x-coordinate of generator * k */
163 if (!EC_POINT_mul(group, tmp_point, k, NULL, NULL, ctx))
165 ECDSAerr(ECDSA_F_ECDSA_SIGN_SETUP, ERR_R_EC_LIB);
168 if (EC_METHOD_get_field_type(EC_GROUP_method_of(group)) == NID_X9_62_prime_field)
170 if (!EC_POINT_get_affine_coordinates_GFp(group,
171 tmp_point, X, NULL, ctx))
173 ECDSAerr(ECDSA_F_ECDSA_SIGN_SETUP,ERR_R_EC_LIB);
177 #ifndef OPENSSL_NO_EC2M
178 else /* NID_X9_62_characteristic_two_field */
180 if (!EC_POINT_get_affine_coordinates_GF2m(group,
181 tmp_point, X, NULL, ctx))
183 ECDSAerr(ECDSA_F_ECDSA_SIGN_SETUP,ERR_R_EC_LIB);
188 if (!BN_nnmod(r, X, order, ctx))
190 ECDSAerr(ECDSA_F_ECDSA_SIGN_SETUP, ERR_R_BN_LIB);
194 while (BN_is_zero(r));
196 /* compute the inverse of k */
197 if (!BN_mod_inverse(k, k, order, ctx))
199 ECDSAerr(ECDSA_F_ECDSA_SIGN_SETUP, ERR_R_BN_LIB);
202 /* clear old values if necessary */
206 BN_clear_free(*kinvp);
207 /* save the pre-computed values */
214 if (k != NULL) BN_clear_free(k);
215 if (r != NULL) BN_clear_free(r);
221 if (tmp_point != NULL)
222 EC_POINT_free(tmp_point);
229 static ECDSA_SIG *ecdsa_do_sign(const unsigned char *dgst, int dgst_len,
230 const BIGNUM *in_kinv, const BIGNUM *in_r, EC_KEY *eckey)
233 BIGNUM *kinv=NULL, *s, *m=NULL,*tmp=NULL,*order=NULL;
236 const EC_GROUP *group;
239 const BIGNUM *priv_key;
242 if(FIPS_selftest_failed())
244 FIPSerr(FIPS_F_ECDSA_DO_SIGN,FIPS_R_FIPS_SELFTEST_FAILED);
249 ecdsa = ecdsa_check(eckey);
250 group = EC_KEY_get0_group(eckey);
251 priv_key = EC_KEY_get0_private_key(eckey);
253 if (group == NULL || priv_key == NULL || ecdsa == NULL)
255 ECDSAerr(ECDSA_F_ECDSA_DO_SIGN, ERR_R_PASSED_NULL_PARAMETER);
260 if (!fips_check_ec_prng(eckey))
264 ret = ECDSA_SIG_new();
267 ECDSAerr(ECDSA_F_ECDSA_DO_SIGN, ERR_R_MALLOC_FAILURE);
272 if ((ctx = BN_CTX_new()) == NULL || (order = BN_new()) == NULL ||
273 (tmp = BN_new()) == NULL || (m = BN_new()) == NULL)
275 ECDSAerr(ECDSA_F_ECDSA_DO_SIGN, ERR_R_MALLOC_FAILURE);
279 if (!EC_GROUP_get_order(group, order, ctx))
281 ECDSAerr(ECDSA_F_ECDSA_DO_SIGN, ERR_R_EC_LIB);
284 i = BN_num_bits(order);
285 /* Need to truncate digest if it is too long: first truncate whole
288 if (8 * dgst_len > i)
289 dgst_len = (i + 7)/8;
290 if (!BN_bin2bn(dgst, dgst_len, m))
292 ECDSAerr(ECDSA_F_ECDSA_DO_SIGN, ERR_R_BN_LIB);
295 /* If still too long truncate remaining bits with a shift */
296 if ((8 * dgst_len > i) && !BN_rshift(m, m, 8 - (i & 0x7)))
298 ECDSAerr(ECDSA_F_ECDSA_DO_SIGN, ERR_R_BN_LIB);
303 if (in_kinv == NULL || in_r == NULL)
305 if (!ecdsa->meth->ecdsa_sign_setup(eckey, ctx,
308 ECDSAerr(ECDSA_F_ECDSA_DO_SIGN,ERR_R_ECDSA_LIB);
316 if (BN_copy(ret->r, in_r) == NULL)
318 ECDSAerr(ECDSA_F_ECDSA_DO_SIGN, ERR_R_MALLOC_FAILURE);
323 if (!BN_mod_mul(tmp, priv_key, ret->r, order, ctx))
325 ECDSAerr(ECDSA_F_ECDSA_DO_SIGN, ERR_R_BN_LIB);
328 if (!BN_mod_add_quick(s, tmp, m, order))
330 ECDSAerr(ECDSA_F_ECDSA_DO_SIGN, ERR_R_BN_LIB);
333 if (!BN_mod_mul(s, s, ckinv, order, ctx))
335 ECDSAerr(ECDSA_F_ECDSA_DO_SIGN, ERR_R_BN_LIB);
340 /* if kinv and r have been supplied by the caller
341 * don't to generate new kinv and r values */
342 if (in_kinv != NULL && in_r != NULL)
344 ECDSAerr(ECDSA_F_ECDSA_DO_SIGN, ECDSA_R_NEED_NEW_SETUP_VALUES);
349 /* s != 0 => we have a valid signature */
374 static int ecdsa_do_verify(const unsigned char *dgst, int dgst_len,
375 const ECDSA_SIG *sig, EC_KEY *eckey)
379 BIGNUM *order, *u1, *u2, *m, *X;
380 EC_POINT *point = NULL;
381 const EC_GROUP *group;
382 const EC_POINT *pub_key;
385 if(FIPS_selftest_failed())
387 FIPSerr(FIPS_F_ECDSA_DO_VERIFY,FIPS_R_FIPS_SELFTEST_FAILED);
392 /* check input values */
393 if (eckey == NULL || (group = EC_KEY_get0_group(eckey)) == NULL ||
394 (pub_key = EC_KEY_get0_public_key(eckey)) == NULL || sig == NULL)
396 ECDSAerr(ECDSA_F_ECDSA_DO_VERIFY, ECDSA_R_MISSING_PARAMETERS);
403 ECDSAerr(ECDSA_F_ECDSA_DO_VERIFY, ERR_R_MALLOC_FAILURE);
407 order = BN_CTX_get(ctx);
408 u1 = BN_CTX_get(ctx);
409 u2 = BN_CTX_get(ctx);
414 ECDSAerr(ECDSA_F_ECDSA_DO_VERIFY, ERR_R_BN_LIB);
418 if (!EC_GROUP_get_order(group, order, ctx))
420 ECDSAerr(ECDSA_F_ECDSA_DO_VERIFY, ERR_R_EC_LIB);
424 if (BN_is_zero(sig->r) || BN_is_negative(sig->r) ||
425 BN_ucmp(sig->r, order) >= 0 || BN_is_zero(sig->s) ||
426 BN_is_negative(sig->s) || BN_ucmp(sig->s, order) >= 0)
428 ECDSAerr(ECDSA_F_ECDSA_DO_VERIFY, ECDSA_R_BAD_SIGNATURE);
429 ret = 0; /* signature is invalid */
432 /* calculate tmp1 = inv(S) mod order */
433 if (!BN_mod_inverse(u2, sig->s, order, ctx))
435 ECDSAerr(ECDSA_F_ECDSA_DO_VERIFY, ERR_R_BN_LIB);
439 i = BN_num_bits(order);
440 /* Need to truncate digest if it is too long: first truncate whole
443 if (8 * dgst_len > i)
444 dgst_len = (i + 7)/8;
445 if (!BN_bin2bn(dgst, dgst_len, m))
447 ECDSAerr(ECDSA_F_ECDSA_DO_VERIFY, ERR_R_BN_LIB);
450 /* If still too long truncate remaining bits with a shift */
451 if ((8 * dgst_len > i) && !BN_rshift(m, m, 8 - (i & 0x7)))
453 ECDSAerr(ECDSA_F_ECDSA_DO_VERIFY, ERR_R_BN_LIB);
456 /* u1 = m * tmp mod order */
457 if (!BN_mod_mul(u1, m, u2, order, ctx))
459 ECDSAerr(ECDSA_F_ECDSA_DO_VERIFY, ERR_R_BN_LIB);
462 /* u2 = r * w mod q */
463 if (!BN_mod_mul(u2, sig->r, u2, order, ctx))
465 ECDSAerr(ECDSA_F_ECDSA_DO_VERIFY, ERR_R_BN_LIB);
469 if ((point = EC_POINT_new(group)) == NULL)
471 ECDSAerr(ECDSA_F_ECDSA_DO_VERIFY, ERR_R_MALLOC_FAILURE);
474 if (!EC_POINT_mul(group, point, u1, pub_key, u2, ctx))
476 ECDSAerr(ECDSA_F_ECDSA_DO_VERIFY, ERR_R_EC_LIB);
479 if (EC_METHOD_get_field_type(EC_GROUP_method_of(group)) == NID_X9_62_prime_field)
481 if (!EC_POINT_get_affine_coordinates_GFp(group,
482 point, X, NULL, ctx))
484 ECDSAerr(ECDSA_F_ECDSA_DO_VERIFY, ERR_R_EC_LIB);
488 #ifndef OPENSSL_NO_EC2M
489 else /* NID_X9_62_characteristic_two_field */
491 if (!EC_POINT_get_affine_coordinates_GF2m(group,
492 point, X, NULL, ctx))
494 ECDSAerr(ECDSA_F_ECDSA_DO_VERIFY, ERR_R_EC_LIB);
499 if (!BN_nnmod(u1, X, order, ctx))
501 ECDSAerr(ECDSA_F_ECDSA_DO_VERIFY, ERR_R_BN_LIB);
504 /* if the signature is correct u1 is equal to sig->r */
505 ret = (BN_ucmp(u1, sig->r) == 0);
510 EC_POINT_free(point);
514 #ifdef OPENSSL_FIPSCANISTER
515 /* FIPS stanadlone version of ecdsa_check: just return FIPS method */
516 ECDSA_DATA *fips_ecdsa_check(EC_KEY *key)
518 static ECDSA_DATA rv = {
524 /* Standalone digest sign and verify */
525 int FIPS_ecdsa_verify_digest(EC_KEY *key,
526 const unsigned char *dig, int dlen, ECDSA_SIG *s)
528 ECDSA_DATA *ecdsa = ecdsa_check(key);
531 return ecdsa->meth->ecdsa_do_verify(dig, dlen, s, key);
533 ECDSA_SIG * FIPS_ecdsa_sign_digest(EC_KEY *key,
534 const unsigned char *dig, int dlen)
536 ECDSA_DATA *ecdsa = ecdsa_check(key);
539 return ecdsa->meth->ecdsa_do_sign(dig, dlen, NULL, NULL, key);