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).
55 /* Copyright (C) 1995-1998 Eric Young (eay@cryptsoft.com)
56 * All rights reserved.
58 * This package is an SSL implementation written
59 * by Eric Young (eay@cryptsoft.com).
60 * The implementation was written so as to conform with Netscapes SSL.
62 * This library is free for commercial and non-commercial use as long as
63 * the following conditions are aheared to. The following conditions
64 * apply to all code found in this distribution, be it the RC4, RSA,
65 * lhash, DES, etc., code; not just the SSL code. The SSL documentation
66 * included with this distribution is covered by the same copyright terms
67 * except that the holder is Tim Hudson (tjh@cryptsoft.com).
69 * Copyright remains Eric Young's, and as such any Copyright notices in
70 * the code are not to be removed.
71 * If this package is used in a product, Eric Young should be given attribution
72 * as the author of the parts of the library used.
73 * This can be in the form of a textual message at program startup or
74 * in documentation (online or textual) provided with the package.
76 * Redistribution and use in source and binary forms, with or without
77 * modification, are permitted provided that the following conditions
79 * 1. Redistributions of source code must retain the copyright
80 * notice, this list of conditions and the following disclaimer.
81 * 2. Redistributions in binary form must reproduce the above copyright
82 * notice, this list of conditions and the following disclaimer in the
83 * documentation and/or other materials provided with the distribution.
84 * 3. All advertising materials mentioning features or use of this software
85 * must display the following acknowledgement:
86 * "This product includes cryptographic software written by
87 * Eric Young (eay@cryptsoft.com)"
88 * The word 'cryptographic' can be left out if the rouines from the library
89 * being used are not cryptographic related :-).
90 * 4. If you include any Windows specific code (or a derivative thereof) from
91 * the apps directory (application code) you must include an acknowledgement:
92 * "This product includes software written by Tim Hudson (tjh@cryptsoft.com)"
94 * THIS SOFTWARE IS PROVIDED BY ERIC YOUNG ``AS IS'' AND
95 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
96 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
97 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
98 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
99 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
100 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
101 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
102 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
103 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
106 * The licence and distribution terms for any publically available version or
107 * derivative of this code cannot be changed. i.e. this code cannot simply be
108 * copied and put under another distribution licence
109 * [including the GNU Public Licence.]
111 #include "cryptlib.h"
112 #include <openssl/ecdsa.h>
114 /* TODO : general case */
115 #define EC_POINT_get_affine_coordinates EC_POINT_get_affine_coordinates_GFp
117 static ECDSA_SIG *ecdsa_do_sign(const unsigned char *dgst, int dlen, ECDSA *ecdsa);
118 static int ecdsa_sign_setup(ECDSA *ecdsa, BN_CTX *ctx_in, BIGNUM **kinvp, BIGNUM **rp);
119 static int ecdsa_do_verify(const unsigned char *dgst, int dgst_len, ECDSA_SIG *sig,
122 static ECDSA_METHOD openssl_ecdsa_meth = {
123 "OpenSSL ECDSA method",
131 const ECDSA_METHOD *ECDSA_OpenSSL(void)
133 return &openssl_ecdsa_meth;
136 static int ecdsa_sign_setup(ECDSA *ecdsa, BN_CTX *ctx_in, BIGNUM **kinvp, BIGNUM **rp)
139 BIGNUM k,*kinv=NULL,*r=NULL,*order=NULL,*X=NULL;
140 EC_POINT *tmp_point=NULL;
141 int ret = 0,reason = ERR_R_BN_LIB;
142 if (!ecdsa || !ecdsa->group || !ecdsa->pub_key || !ecdsa->priv_key)
144 reason = ECDSA_R_MISSING_PARAMETERS;
149 if ((ctx=BN_CTX_new()) == NULL) goto err;
154 if ((r = BN_new()) == NULL) goto err;
155 if ((order = BN_new()) == NULL) goto err;
156 if ((X = BN_new()) == NULL) goto err;
157 if ((tmp_point = EC_POINT_new(ecdsa->group)) == NULL)
159 reason = ERR_R_EC_LIB;
162 if (!EC_POINT_copy(tmp_point,EC_GROUP_get0_generator(ecdsa->group)))
164 reason = ERR_R_EC_LIB;
167 if (!EC_GROUP_get_order(ecdsa->group,order,ctx))
169 reason = ERR_R_EC_LIB;
178 if (!BN_rand_range(&k,order))
180 reason = ECDSA_R_RANDOM_NUMBER_GENERATION_FAILED;
183 while (BN_is_zero(&k));
185 /* compute r the x-coordinate of generator * k */
186 if (!EC_POINT_mul(ecdsa->group,tmp_point,&k,NULL,NULL,ctx)
187 || !EC_POINT_get_affine_coordinates(ecdsa->group,tmp_point,X,NULL,ctx))
189 reason = ERR_R_EC_LIB;
192 if (!BN_nnmod(r,X,order,ctx)) goto err;
194 while (BN_is_zero(r));
196 /* compute the inverse of k */
197 if ((kinv = BN_mod_inverse(NULL,&k,order,ctx)) == NULL) goto err;
203 BN_clear_free(*kinvp);
210 ECDSAerr(ECDSA_F_ECDSA_SIGN_SETUP,reason);
211 if (kinv != NULL) BN_clear_free(kinv);
212 if (r != NULL) BN_clear_free(r);
219 BN_clear_free(order);
220 if (tmp_point != NULL)
221 EC_POINT_free(tmp_point);
222 if (X) BN_clear_free(X);
228 static ECDSA_SIG *ecdsa_do_sign(const unsigned char *dgst, int dgst_len, ECDSA *ecdsa)
230 BIGNUM *kinv=NULL,*r=NULL,*s=NULL,*m=NULL,*tmp=NULL,*order=NULL;
233 int reason=ERR_R_BN_LIB;
236 if (!ecdsa || !ecdsa->group || !ecdsa->pub_key || !ecdsa->priv_key)
238 reason = ECDSA_R_MISSING_PARAMETERS;
243 if ((ctx = BN_CTX_new()) == NULL) goto err;
244 if ((order = BN_new()) == NULL) goto err;
245 if ((tmp = BN_new()) == NULL) goto err;
246 if ((m = BN_new()) == NULL) goto err;
247 if ((s = BN_new()) == NULL) goto err;
249 if (!EC_GROUP_get_order(ecdsa->group,order,ctx))
251 reason = ECDSA_R_ERR_EC_LIB;
254 if (dgst_len > BN_num_bytes(order))
256 reason = ECDSA_R_DATA_TOO_LARGE_FOR_KEY_SIZE;
260 if (BN_bin2bn(dgst,dgst_len,m) == NULL) goto err;
263 if ((ecdsa->kinv == NULL) || (ecdsa->r == NULL))
265 if (!ECDSA_sign_setup(ecdsa,ctx,&kinv,&r)) goto err;
275 if (!BN_mod_mul(tmp,ecdsa->priv_key,r,order,ctx)) goto err;
276 if (!BN_add(s,tmp,m)) goto err;
277 if (BN_cmp(s,order) > 0)
279 if (!BN_mod_mul(s,s,kinv,order,ctx)) goto err;
281 while (BN_is_zero(s));
283 if ((ret = ECDSA_SIG_new()) == NULL)
285 reason = ECDSA_R_SIGNATURE_MALLOC_FAILED;
288 if (BN_copy(ret->r, r) == NULL || BN_copy(ret->s, s) == NULL)
292 reason = ERR_R_BN_LIB;
298 ECDSAerr(ECDSA_F_ECDSA_DO_SIGN,reason);
300 if (r != NULL) BN_clear_free(r);
301 if (s != NULL) BN_clear_free(s);
302 if (ctx != NULL) BN_CTX_free(ctx);
303 if (m != NULL) BN_clear_free(m);
304 if (tmp != NULL) BN_clear_free(tmp);
305 if (order != NULL) BN_clear_free(order);
306 if (kinv != NULL) BN_clear_free(kinv);
310 static int ecdsa_do_verify(const unsigned char *dgst, int dgst_len, ECDSA_SIG *sig,
314 BIGNUM *order=NULL,*u1=NULL,*u2=NULL,*m=NULL,*X=NULL;
315 EC_POINT *point=NULL;
316 int ret = -1,reason = ERR_R_BN_LIB;
317 if (!ecdsa || !ecdsa->group || !ecdsa->pub_key || !sig)
319 reason = ECDSA_R_MISSING_PARAMETERS;
323 if ((ctx = BN_CTX_new()) == NULL) goto err;
324 if ((order = BN_new()) == NULL) goto err;
325 if ((u1 = BN_new()) == NULL) goto err;
326 if ((u2 = BN_new()) == NULL) goto err;
327 if ((m = BN_new()) == NULL) goto err;
328 if ((X = BN_new()) == NULL) goto err;
329 if (!EC_GROUP_get_order(ecdsa->group,order,ctx)) goto err;
331 if (BN_is_zero(sig->r) || sig->r->neg || BN_ucmp(sig->r, order) >= 0)
333 reason = ECDSA_R_BAD_SIGNATURE;
337 if (BN_is_zero(sig->s) || sig->s->neg || BN_ucmp(sig->s, order) >= 0)
339 reason = ECDSA_R_BAD_SIGNATURE;
344 /* calculate tmp1 = inv(S) mod order */
345 if ((BN_mod_inverse(u2,sig->s,order,ctx)) == NULL) goto err;
347 if (BN_bin2bn(dgst,dgst_len,m) == NULL) goto err;
348 /* u1 = m * tmp mod order */
349 if (!BN_mod_mul(u1,m,u2,order,ctx)) goto err;
350 /* u2 = r * w mod q */
351 if (!BN_mod_mul(u2,sig->r,u2,order,ctx)) goto err;
353 if ((point = EC_POINT_new(ecdsa->group)) == NULL)
355 reason = ERR_R_EC_LIB;
358 if (!EC_POINT_copy(point,EC_GROUP_get0_generator(ecdsa->group)))
360 reason = ERR_R_EC_LIB;
363 if (!EC_POINT_mul(ecdsa->group,point,u1,ecdsa->pub_key,u2,ctx)
364 || !EC_POINT_get_affine_coordinates(ecdsa->group,point,X,NULL,ctx))
366 reason = ERR_R_EC_LIB;
369 if (!BN_nnmod(u1,X,order,ctx)) goto err;
371 /* is now in u1. If the signature is correct, it will be
373 ret = (BN_ucmp(u1,sig->r) == 0);
376 if (ret != 1) ECDSAerr(ECDSA_F_ECDSA_DO_VERIFY,reason);
377 if (ctx != NULL) BN_CTX_free(ctx);
378 if (u1 != NULL) BN_clear_free(u1);
379 if (u2 != NULL) BN_clear_free(u2);
380 if (m != NULL) BN_clear_free(m);
381 if (X != NULL) BN_clear_free(X);
382 if (order != NULL) BN_clear_free(order);
383 if (point != NULL) EC_POINT_free(point);