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
42 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE OpenSSL PROJECT OR
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",
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);
141 if (!BN_rand_range(k, order))
143 ECDSAerr(ECDSA_F_ECDSA_SIGN_SETUP,
144 ECDSA_R_RANDOM_NUMBER_GENERATION_FAILED);
147 while (BN_is_zero(k));
149 /* compute r the x-coordinate of generator * k */
150 if (!EC_POINT_mul(group, tmp_point, k, NULL, NULL, ctx))
152 ECDSAerr(ECDSA_F_ECDSA_SIGN_SETUP, ERR_R_EC_LIB);
155 if (EC_METHOD_get_field_type(EC_GROUP_method_of(group)) == NID_X9_62_prime_field)
157 if (!EC_POINT_get_affine_coordinates_GFp(group,
158 tmp_point, X, NULL, ctx))
160 ECDSAerr(ECDSA_F_ECDSA_SIGN_SETUP,ERR_R_EC_LIB);
164 #ifndef OPENSSL_NO_EC2M
165 else /* NID_X9_62_characteristic_two_field */
167 if (!EC_POINT_get_affine_coordinates_GF2m(group,
168 tmp_point, X, NULL, ctx))
170 ECDSAerr(ECDSA_F_ECDSA_SIGN_SETUP,ERR_R_EC_LIB);
175 if (!BN_nnmod(r, X, order, ctx))
177 ECDSAerr(ECDSA_F_ECDSA_SIGN_SETUP, ERR_R_BN_LIB);
181 while (BN_is_zero(r));
183 /* compute the inverse of k */
184 if (!BN_mod_inverse(k, k, order, ctx))
186 ECDSAerr(ECDSA_F_ECDSA_SIGN_SETUP, ERR_R_BN_LIB);
189 /* clear old values if necessary */
193 BN_clear_free(*kinvp);
194 /* save the pre-computed values */
201 if (k != NULL) BN_clear_free(k);
202 if (r != NULL) BN_clear_free(r);
208 if (tmp_point != NULL)
209 EC_POINT_free(tmp_point);
216 static ECDSA_SIG *ecdsa_do_sign(const unsigned char *dgst, int dgst_len,
217 const BIGNUM *in_kinv, const BIGNUM *in_r, EC_KEY *eckey)
220 BIGNUM *kinv=NULL, *s, *m=NULL,*tmp=NULL,*order=NULL;
223 const EC_GROUP *group;
226 const BIGNUM *priv_key;
228 ecdsa = ecdsa_check(eckey);
229 group = EC_KEY_get0_group(eckey);
230 priv_key = EC_KEY_get0_private_key(eckey);
232 if (group == NULL || priv_key == NULL || ecdsa == NULL)
234 ECDSAerr(ECDSA_F_ECDSA_DO_SIGN, ERR_R_PASSED_NULL_PARAMETER);
238 ret = ECDSA_SIG_new();
241 ECDSAerr(ECDSA_F_ECDSA_DO_SIGN, ERR_R_MALLOC_FAILURE);
246 if ((ctx = BN_CTX_new()) == NULL || (order = BN_new()) == NULL ||
247 (tmp = BN_new()) == NULL || (m = BN_new()) == NULL)
249 ECDSAerr(ECDSA_F_ECDSA_DO_SIGN, ERR_R_MALLOC_FAILURE);
253 if (!EC_GROUP_get_order(group, order, ctx))
255 ECDSAerr(ECDSA_F_ECDSA_DO_SIGN, ERR_R_EC_LIB);
258 i = BN_num_bits(order);
259 /* Need to truncate digest if it is too long: first truncate whole
262 if (8 * dgst_len > i)
263 dgst_len = (i + 7)/8;
264 if (!BN_bin2bn(dgst, dgst_len, m))
266 ECDSAerr(ECDSA_F_ECDSA_DO_SIGN, ERR_R_BN_LIB);
269 /* If still too long truncate remaining bits with a shift */
270 if ((8 * dgst_len > i) && !BN_rshift(m, m, 8 - (i & 0x7)))
272 ECDSAerr(ECDSA_F_ECDSA_DO_SIGN, ERR_R_BN_LIB);
277 if (in_kinv == NULL || in_r == NULL)
279 if (!ecdsa->meth->ecdsa_sign_setup(eckey, ctx,
282 ECDSAerr(ECDSA_F_ECDSA_DO_SIGN,ERR_R_ECDSA_LIB);
290 if (BN_copy(ret->r, in_r) == NULL)
292 ECDSAerr(ECDSA_F_ECDSA_DO_SIGN, ERR_R_MALLOC_FAILURE);
297 if (!BN_mod_mul(tmp, priv_key, ret->r, order, ctx))
299 ECDSAerr(ECDSA_F_ECDSA_DO_SIGN, ERR_R_BN_LIB);
302 if (!BN_mod_add_quick(s, tmp, m, order))
304 ECDSAerr(ECDSA_F_ECDSA_DO_SIGN, ERR_R_BN_LIB);
307 if (!BN_mod_mul(s, s, ckinv, order, ctx))
309 ECDSAerr(ECDSA_F_ECDSA_DO_SIGN, ERR_R_BN_LIB);
314 /* if kinv and r have been supplied by the caller
315 * don't to generate new kinv and r values */
316 if (in_kinv != NULL && in_r != NULL)
318 ECDSAerr(ECDSA_F_ECDSA_DO_SIGN, ECDSA_R_NEED_NEW_SETUP_VALUES);
323 /* s != 0 => we have a valid signature */
348 static int ecdsa_do_verify(const unsigned char *dgst, int dgst_len,
349 const ECDSA_SIG *sig, EC_KEY *eckey)
353 BIGNUM *order, *u1, *u2, *m, *X;
354 EC_POINT *point = NULL;
355 const EC_GROUP *group;
356 const EC_POINT *pub_key;
358 /* check input values */
359 if (eckey == NULL || (group = EC_KEY_get0_group(eckey)) == NULL ||
360 (pub_key = EC_KEY_get0_public_key(eckey)) == NULL || sig == NULL)
362 ECDSAerr(ECDSA_F_ECDSA_DO_VERIFY, ECDSA_R_MISSING_PARAMETERS);
369 ECDSAerr(ECDSA_F_ECDSA_DO_VERIFY, ERR_R_MALLOC_FAILURE);
373 order = BN_CTX_get(ctx);
374 u1 = BN_CTX_get(ctx);
375 u2 = BN_CTX_get(ctx);
380 ECDSAerr(ECDSA_F_ECDSA_DO_VERIFY, ERR_R_BN_LIB);
384 if (!EC_GROUP_get_order(group, order, ctx))
386 ECDSAerr(ECDSA_F_ECDSA_DO_VERIFY, ERR_R_EC_LIB);
390 if (BN_is_zero(sig->r) || BN_is_negative(sig->r) ||
391 BN_ucmp(sig->r, order) >= 0 || BN_is_zero(sig->s) ||
392 BN_is_negative(sig->s) || BN_ucmp(sig->s, order) >= 0)
394 ECDSAerr(ECDSA_F_ECDSA_DO_VERIFY, ECDSA_R_BAD_SIGNATURE);
395 ret = 0; /* signature is invalid */
398 /* calculate tmp1 = inv(S) mod order */
399 if (!BN_mod_inverse(u2, sig->s, order, ctx))
401 ECDSAerr(ECDSA_F_ECDSA_DO_VERIFY, ERR_R_BN_LIB);
405 i = BN_num_bits(order);
406 /* Need to truncate digest if it is too long: first truncate whole
409 if (8 * dgst_len > i)
410 dgst_len = (i + 7)/8;
411 if (!BN_bin2bn(dgst, dgst_len, m))
413 ECDSAerr(ECDSA_F_ECDSA_DO_VERIFY, ERR_R_BN_LIB);
416 /* If still too long truncate remaining bits with a shift */
417 if ((8 * dgst_len > i) && !BN_rshift(m, m, 8 - (i & 0x7)))
419 ECDSAerr(ECDSA_F_ECDSA_DO_VERIFY, ERR_R_BN_LIB);
422 /* u1 = m * tmp mod order */
423 if (!BN_mod_mul(u1, m, u2, order, ctx))
425 ECDSAerr(ECDSA_F_ECDSA_DO_VERIFY, ERR_R_BN_LIB);
428 /* u2 = r * w mod q */
429 if (!BN_mod_mul(u2, sig->r, u2, order, ctx))
431 ECDSAerr(ECDSA_F_ECDSA_DO_VERIFY, ERR_R_BN_LIB);
435 if ((point = EC_POINT_new(group)) == NULL)
437 ECDSAerr(ECDSA_F_ECDSA_DO_VERIFY, ERR_R_MALLOC_FAILURE);
440 if (!EC_POINT_mul(group, point, u1, pub_key, u2, ctx))
442 ECDSAerr(ECDSA_F_ECDSA_DO_VERIFY, ERR_R_EC_LIB);
445 if (EC_METHOD_get_field_type(EC_GROUP_method_of(group)) == NID_X9_62_prime_field)
447 if (!EC_POINT_get_affine_coordinates_GFp(group,
448 point, X, NULL, ctx))
450 ECDSAerr(ECDSA_F_ECDSA_DO_VERIFY, ERR_R_EC_LIB);
454 #ifndef OPENSSL_NO_EC2M
455 else /* NID_X9_62_characteristic_two_field */
457 if (!EC_POINT_get_affine_coordinates_GF2m(group,
458 point, X, NULL, ctx))
460 ECDSAerr(ECDSA_F_ECDSA_DO_VERIFY, ERR_R_EC_LIB);
465 if (!BN_nnmod(u1, X, order, ctx))
467 ECDSAerr(ECDSA_F_ECDSA_DO_VERIFY, ERR_R_BN_LIB);
470 /* if the signature is correct u1 is equal to sig->r */
471 ret = (BN_ucmp(u1, sig->r) == 0);
476 EC_POINT_free(point);
480 #ifdef OPENSSL_FIPSCANISTER
481 /* FIPS stanadlone version of ecdsa_check: just return FIPS method */
482 ECDSA_DATA *fips_ecdsa_check(EC_KEY *key)
484 static ECDSA_DATA rv = {
490 /* Standalone digest sign and verify */
491 int FIPS_ecdsa_verify_digest(EC_KEY *key,
492 const unsigned char *dig, int dlen, ECDSA_SIG *s)
494 ECDSA_DATA *ecdsa = ecdsa_check(key);
497 return ecdsa->meth->ecdsa_do_verify(dig, dlen, s, key);
499 ECDSA_SIG * FIPS_ecdsa_sign_digest(EC_KEY *key,
500 const unsigned char *dig, int dlen)
502 ECDSA_DATA *ecdsa = ecdsa_check(key);
505 return ecdsa->meth->ecdsa_do_sign(dig, dlen, NULL, NULL, key);