1 /* Copyright (C) 1995-1998 Eric Young (eay@cryptsoft.com)
4 * This package is an SSL implementation written
5 * by Eric Young (eay@cryptsoft.com).
6 * The implementation was written so as to conform with Netscapes SSL.
8 * This library is free for commercial and non-commercial use as long as
9 * the following conditions are aheared to. The following conditions
10 * apply to all code found in this distribution, be it the RC4, RSA,
11 * lhash, DES, etc., code; not just the SSL code. The SSL documentation
12 * included with this distribution is covered by the same copyright terms
13 * except that the holder is Tim Hudson (tjh@cryptsoft.com).
15 * Copyright remains Eric Young's, and as such any Copyright notices in
16 * the code are not to be removed.
17 * If this package is used in a product, Eric Young should be given attribution
18 * as the author of the parts of the library used.
19 * This can be in the form of a textual message at program startup or
20 * in documentation (online or textual) provided with the package.
22 * Redistribution and use in source and binary forms, with or without
23 * modification, are permitted provided that the following conditions
25 * 1. Redistributions of source code must retain the copyright
26 * notice, this list of conditions and the following disclaimer.
27 * 2. Redistributions in binary form must reproduce the above copyright
28 * notice, this list of conditions and the following disclaimer in the
29 * documentation and/or other materials provided with the distribution.
30 * 3. All advertising materials mentioning features or use of this software
31 * must display the following acknowledgement:
32 * "This product includes cryptographic software written by
33 * Eric Young (eay@cryptsoft.com)"
34 * The word 'cryptographic' can be left out if the rouines from the library
35 * being used are not cryptographic related :-).
36 * 4. If you include any Windows specific code (or a derivative thereof) from
37 * the apps directory (application code) you must include an acknowledgement:
38 * "This product includes software written by Tim Hudson (tjh@cryptsoft.com)"
40 * THIS SOFTWARE IS PROVIDED BY ERIC YOUNG ``AS IS'' AND
41 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
42 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
43 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
44 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
45 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
46 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
47 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
48 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
49 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
52 * The licence and distribution terms for any publically available version or
53 * derivative of this code cannot be changed. i.e. this code cannot simply be
54 * copied and put under another distribution licence
55 * [including the GNU Public Licence.]
58 #include <openssl/ecdsa.h>
60 int ECDSA_generate_key(ECDSA *ecdsa)
64 BIGNUM *priv_key=NULL,*order=NULL;
65 EC_POINT *pub_key=NULL;
67 if (!ecdsa || !ecdsa->group)
69 ECDSAerr(ECDSA_F_ECDSA_GENERATE_KEY,ECDSA_R_MISSING_PARAMETERS);
73 if ((order = BN_new()) == NULL) goto err;
74 if ((ctx = BN_CTX_new()) == NULL) goto err;
76 if (ecdsa->priv_key == NULL)
78 if ((priv_key = BN_new()) == NULL) goto err;
81 priv_key = ecdsa->priv_key;
83 if (!EC_GROUP_get_order(ecdsa->group, order, ctx)) goto err;
85 if (!BN_rand_range(priv_key, order)) goto err;
86 while (BN_is_zero(priv_key));
88 if (ecdsa->pub_key == NULL)
90 if ((pub_key = EC_POINT_new(ecdsa->group)) == NULL) goto err;
93 pub_key = ecdsa->pub_key;
95 if (!EC_POINT_copy(pub_key, EC_GROUP_get0_generator(ecdsa->group))) goto err;
96 if (!EC_POINT_mul(ecdsa->group, pub_key, priv_key, NULL, NULL, ctx)) goto err;
98 ecdsa->priv_key = priv_key;
99 ecdsa->pub_key = pub_key;
101 err: if (order) BN_free(order);
102 if ((pub_key != NULL) && (ecdsa->pub_key == NULL)) EC_POINT_free(pub_key);
103 if ((priv_key != NULL) && (ecdsa->priv_key == NULL)) BN_free(priv_key);
104 if (ctx != NULL) BN_CTX_free(ctx);
108 int ECDSA_check_key(ECDSA *ecdsa)
113 EC_POINT *point=NULL;
115 if (!ecdsa || !ecdsa->group || !ecdsa->pub_key)
118 if ((ctx = BN_CTX_new()) == NULL) goto err;
119 if ((order = BN_new()) == NULL) goto err;
120 if ((point = EC_POINT_new(ecdsa->group)) == NULL) goto err;
122 /* testing whether pub_key is a valid point on the elliptic curve */
123 if (!EC_POINT_is_on_curve(ecdsa->group,ecdsa->pub_key,ctx)) goto err;
124 /* testing whether pub_key * order is the point at infinity */
125 if (!EC_GROUP_get_order(ecdsa->group,order,ctx)) goto err;
126 if (!EC_POINT_copy(point,ecdsa->pub_key)) goto err;
127 if (!EC_POINT_mul(ecdsa->group,point,order,NULL,NULL,ctx)) goto err;
128 if (!EC_POINT_is_at_infinity(ecdsa->group,point)) goto err;
129 /* in case the priv_key is present : check if generator * priv_key == pub_key */
132 if (BN_cmp(ecdsa->priv_key,order) >= 0) goto err;
133 if (!EC_POINT_copy(point,EC_GROUP_get0_generator(ecdsa->group))) goto err;
134 if (!EC_POINT_mul(ecdsa->group,point,ecdsa->priv_key,NULL,NULL,ctx)) goto err;
135 if (EC_POINT_cmp(ecdsa->group,point,ecdsa->pub_key,ctx) != 0) goto err;
139 if (ctx != NULL) BN_CTX_free(ctx);
140 if (order != NULL) BN_free(order);
141 if (point != NULL) EC_POINT_free(point);