1 /* crypto/ecdsa/ecs_ossl.c */
2 /* ====================================================================
3 * Copyright (c) 1998-2002 The OpenSSL Project. All rights reserved.
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
9 * 1. Redistributions of source code must retain the above copyright
10 * notice, this list of conditions and the following disclaimer.
12 * 2. Redistributions in binary form must reproduce the above copyright
13 * notice, this list of conditions and the following disclaimer in
14 * the documentation and/or other materials provided with the
17 * 3. All advertising materials mentioning features or use of this
18 * software must display the following acknowledgment:
19 * "This product includes software developed by the OpenSSL Project
20 * for use in the OpenSSL Toolkit. (http://www.OpenSSL.org/)"
22 * 4. The names "OpenSSL Toolkit" and "OpenSSL Project" must not be used to
23 * endorse or promote products derived from this software without
24 * prior written permission. For written permission, please contact
25 * openssl-core@OpenSSL.org.
27 * 5. Products derived from this software may not be called "OpenSSL"
28 * nor may "OpenSSL" appear in their names without prior written
29 * permission of the OpenSSL Project.
31 * 6. Redistributions of any form whatsoever must retain the following
33 * "This product includes software developed by the OpenSSL Project
34 * for use in the OpenSSL Toolkit (http://www.OpenSSL.org/)"
36 * THIS SOFTWARE IS PROVIDED BY THE OpenSSL PROJECT ``AS IS'' AND ANY
37 * EXPRESSED OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
38 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
39 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE OpenSSL PROJECT OR
40 * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
41 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
42 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
43 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
44 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
45 * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
46 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
47 * OF THE POSSIBILITY OF SUCH DAMAGE.
48 * ====================================================================
50 * This product includes cryptographic software written by Eric Young
51 * (eay@cryptsoft.com). This product includes software written by Tim
52 * Hudson (tjh@cryptsoft.com).
57 #include <openssl/err.h>
59 /* TODO : general case */
60 #define EC_POINT_get_affine_coordinates EC_POINT_get_affine_coordinates_GFp
62 static ECDSA_SIG *ecdsa_do_sign(const unsigned char *dgst, int dlen, ECDSA *ecdsa);
63 static int ecdsa_sign_setup(ECDSA *ecdsa, BN_CTX *ctx_in, BIGNUM **kinvp, BIGNUM **rp);
64 static int ecdsa_do_verify(const unsigned char *dgst, int dgst_len, ECDSA_SIG *sig,
67 static ECDSA_METHOD openssl_ecdsa_meth = {
68 "OpenSSL ECDSA method",
76 const ECDSA_METHOD *ECDSA_OpenSSL(void)
78 return &openssl_ecdsa_meth;
81 static int ecdsa_sign_setup(ECDSA *ecdsa, BN_CTX *ctx_in, BIGNUM **kinvp, BIGNUM **rp)
84 BIGNUM k,*kinv=NULL,*r=NULL,*order=NULL,*X=NULL;
85 EC_POINT *tmp_point=NULL;
86 int ret = 0,reason = ERR_R_BN_LIB;
87 if (!ecdsa || !ecdsa->group || !ecdsa->pub_key || !ecdsa->priv_key)
89 reason = ECDSA_R_MISSING_PARAMETERS;
94 if ((ctx=BN_CTX_new()) == NULL) goto err;
99 if ((r = BN_new()) == NULL) goto err;
100 if ((order = BN_new()) == NULL) goto err;
101 if ((X = BN_new()) == NULL) goto err;
102 if ((tmp_point = EC_POINT_new(ecdsa->group)) == NULL)
104 reason = ERR_R_EC_LIB;
107 if (!EC_GROUP_get_order(ecdsa->group,order,ctx))
109 reason = ERR_R_EC_LIB;
118 if (!BN_rand_range(&k,order))
120 reason = ECDSA_R_RANDOM_NUMBER_GENERATION_FAILED;
123 while (BN_is_zero(&k));
125 /* compute r the x-coordinate of generator * k */
126 if (!EC_POINT_mul(ecdsa->group,tmp_point,&k,NULL,NULL,ctx)
127 || !EC_POINT_get_affine_coordinates(ecdsa->group,tmp_point,X,NULL,ctx))
129 reason = ERR_R_EC_LIB;
132 if (!BN_nnmod(r,X,order,ctx)) goto err;
134 while (BN_is_zero(r));
136 /* compute the inverse of k */
137 if ((kinv = BN_mod_inverse(NULL,&k,order,ctx)) == NULL) goto err;
143 BN_clear_free(*kinvp);
150 ECDSAerr(ECDSA_F_ECDSA_SIGN_SETUP,reason);
151 if (kinv != NULL) BN_clear_free(kinv);
152 if (r != NULL) BN_clear_free(r);
159 BN_clear_free(order);
160 if (tmp_point != NULL)
161 EC_POINT_free(tmp_point);
162 if (X) BN_clear_free(X);
168 static ECDSA_SIG *ecdsa_do_sign(const unsigned char *dgst, int dgst_len, ECDSA *ecdsa)
170 BIGNUM *kinv=NULL,*r=NULL,*s=NULL,*m=NULL,*tmp=NULL,*order=NULL;
173 int reason=ERR_R_BN_LIB;
176 if (!ecdsa || !ecdsa->group || !ecdsa->pub_key || !ecdsa->priv_key)
178 reason = ECDSA_R_MISSING_PARAMETERS;
183 if ((ctx = BN_CTX_new()) == NULL) goto err;
184 if ((order = BN_new()) == NULL) goto err;
185 if ((tmp = BN_new()) == NULL) goto err;
186 if ((m = BN_new()) == NULL) goto err;
187 if ((s = BN_new()) == NULL) goto err;
189 if (!EC_GROUP_get_order(ecdsa->group,order,ctx))
191 reason = ECDSA_R_ERR_EC_LIB;
194 if (dgst_len > BN_num_bytes(order))
196 reason = ECDSA_R_DATA_TOO_LARGE_FOR_KEY_SIZE;
200 if (BN_bin2bn(dgst,dgst_len,m) == NULL) goto err;
203 if ((ecdsa->kinv == NULL) || (ecdsa->r == NULL))
205 if (!ECDSA_sign_setup(ecdsa,ctx,&kinv,&r)) goto err;
215 if (!BN_mod_mul(tmp,ecdsa->priv_key,r,order,ctx)) goto err;
216 if (!BN_add(s,tmp,m)) goto err;
217 if (BN_cmp(s,order) > 0)
219 if (!BN_mod_mul(s,s,kinv,order,ctx)) goto err;
221 while (BN_is_zero(s));
223 if ((ret = ECDSA_SIG_new()) == NULL)
225 reason = ECDSA_R_SIGNATURE_MALLOC_FAILED;
228 if (BN_copy(ret->r, r) == NULL || BN_copy(ret->s, s) == NULL)
232 reason = ERR_R_BN_LIB;
238 ECDSAerr(ECDSA_F_ECDSA_DO_SIGN,reason);
240 if (r != NULL) BN_clear_free(r);
241 if (s != NULL) BN_clear_free(s);
242 if (ctx != NULL) BN_CTX_free(ctx);
243 if (m != NULL) BN_clear_free(m);
244 if (tmp != NULL) BN_clear_free(tmp);
245 if (order != NULL) BN_clear_free(order);
246 if (kinv != NULL) BN_clear_free(kinv);
250 static int ecdsa_do_verify(const unsigned char *dgst, int dgst_len, ECDSA_SIG *sig,
254 BIGNUM *order=NULL,*u1=NULL,*u2=NULL,*m=NULL,*X=NULL;
255 EC_POINT *point=NULL;
256 int ret = -1,reason = ERR_R_BN_LIB;
257 if (!ecdsa || !ecdsa->group || !ecdsa->pub_key || !sig)
259 reason = ECDSA_R_MISSING_PARAMETERS;
263 if ((ctx = BN_CTX_new()) == NULL) goto err;
264 if ((order = BN_new()) == NULL) goto err;
265 if ((u1 = BN_new()) == NULL) goto err;
266 if ((u2 = BN_new()) == NULL) goto err;
267 if ((m = BN_new()) == NULL) goto err;
268 if ((X = BN_new()) == NULL) goto err;
269 if (!EC_GROUP_get_order(ecdsa->group,order,ctx)) goto err;
271 if (BN_is_zero(sig->r) || sig->r->neg || BN_ucmp(sig->r, order) >= 0)
273 reason = ECDSA_R_BAD_SIGNATURE;
277 if (BN_is_zero(sig->s) || sig->s->neg || BN_ucmp(sig->s, order) >= 0)
279 reason = ECDSA_R_BAD_SIGNATURE;
284 /* calculate tmp1 = inv(S) mod order */
285 if ((BN_mod_inverse(u2,sig->s,order,ctx)) == NULL) goto err;
287 if (BN_bin2bn(dgst,dgst_len,m) == NULL) goto err;
288 /* u1 = m * tmp mod order */
289 if (!BN_mod_mul(u1,m,u2,order,ctx)) goto err;
290 /* u2 = r * w mod q */
291 if (!BN_mod_mul(u2,sig->r,u2,order,ctx)) goto err;
293 if ((point = EC_POINT_new(ecdsa->group)) == NULL)
295 reason = ERR_R_EC_LIB;
298 if (!EC_POINT_mul(ecdsa->group,point,u1,ecdsa->pub_key,u2,ctx)
299 || !EC_POINT_get_affine_coordinates(ecdsa->group,point,X,NULL,ctx))
301 reason = ERR_R_EC_LIB;
304 if (!BN_nnmod(u1,X,order,ctx)) goto err;
306 /* is now in u1. If the signature is correct, it will be
308 ret = (BN_ucmp(u1,sig->r) == 0);
311 if (ret != 1) ECDSAerr(ECDSA_F_ECDSA_DO_VERIFY,reason);
312 if (ctx != NULL) BN_CTX_free(ctx);
313 if (u1 != NULL) BN_clear_free(u1);
314 if (u2 != NULL) BN_clear_free(u2);
315 if (m != NULL) BN_clear_free(m);
316 if (X != NULL) BN_clear_free(X);
317 if (order != NULL) BN_clear_free(order);
318 if (point != NULL) EC_POINT_free(point);