1/* ====================================================================
2 * Copyright (c) 1998-2005 The OpenSSL Project.  All rights reserved.
3 *
4 * Redistribution and use in source and binary forms, with or without
5 * modification, are permitted provided that the following conditions
6 * are met:
7 *
8 * 1. Redistributions of source code must retain the above copyright
9 *    notice, this list of conditions and the following disclaimer.
10 *
11 * 2. Redistributions in binary form must reproduce the above copyright
12 *    notice, this list of conditions and the following disclaimer in
13 *    the documentation and/or other materials provided with the
14 *    distribution.
15 *
16 * 3. All advertising materials mentioning features or use of this
17 *    software must display the following acknowledgment:
18 *    "This product includes software developed by the OpenSSL Project
19 *    for use in the OpenSSL Toolkit. (http://www.OpenSSL.org/)"
20 *
21 * 4. The names "OpenSSL Toolkit" and "OpenSSL Project" must not be used to
22 *    endorse or promote products derived from this software without
23 *    prior written permission. For written permission, please contact
24 *    openssl-core@OpenSSL.org.
25 *
26 * 5. Products derived from this software may not be called "OpenSSL"
27 *    nor may "OpenSSL" appear in their names without prior written
28 *    permission of the OpenSSL Project.
29 *
30 * 6. Redistributions of any form whatsoever must retain the following
31 *    acknowledgment:
32 *    "This product includes software developed by the OpenSSL Project
33 *    for use in the OpenSSL Toolkit (http://www.OpenSSL.org/)"
34 *
35 * THIS SOFTWARE IS PROVIDED BY THE OpenSSL PROJECT ``AS IS'' AND ANY
36 * EXPRESSED OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
37 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
38 * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE OpenSSL PROJECT OR
39 * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
40 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
41 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
42 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
43 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
44 * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
45 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
46 * OF THE POSSIBILITY OF SUCH DAMAGE.
47 * ====================================================================
48 *
49 * This product includes cryptographic software written by Eric Young
50 * (eay@cryptsoft.com).  This product includes software written by Tim
51 * Hudson (tjh@cryptsoft.com). */
52
53#include <openssl/ecdsa.h>
54
55#include <openssl/asn1.h>
56#include <openssl/asn1t.h>
57#include <openssl/ec_key.h>
58
59#include "../ec/internal.h"
60
61
62ASN1_SEQUENCE(ECDSA_SIG) = {
63    ASN1_SIMPLE(ECDSA_SIG, r, CBIGNUM),
64    ASN1_SIMPLE(ECDSA_SIG, s, CBIGNUM),
65} ASN1_SEQUENCE_END(ECDSA_SIG);
66
67DECLARE_ASN1_FUNCTIONS_const(ECDSA_SIG);
68DECLARE_ASN1_ENCODE_FUNCTIONS_const(ECDSA_SIG, ECDSA_SIG);
69IMPLEMENT_ASN1_FUNCTIONS_const(ECDSA_SIG);
70
71size_t ECDSA_size(const EC_KEY *key) {
72  size_t ret, i, group_order_size;
73  ASN1_INTEGER bs;
74  BIGNUM *order = NULL;
75  unsigned char buf[4];
76  const EC_GROUP *group;
77
78  if (key->ecdsa_meth && key->ecdsa_meth->group_order_size) {
79    group_order_size = key->ecdsa_meth->group_order_size(key);
80  } else {
81    size_t num_bits;
82
83    if (key == NULL) {
84      return 0;
85    }
86    group = EC_KEY_get0_group(key);
87    if (group == NULL) {
88      return 0;
89    }
90
91    order = BN_new();
92    if (order == NULL) {
93      return 0;
94    }
95    if (!EC_GROUP_get_order(group, order, NULL)) {
96      BN_clear_free(order);
97      return 0;
98    }
99
100    num_bits = BN_num_bits(order);
101    group_order_size = (num_bits + 7) / 8;
102  }
103
104  bs.length = group_order_size;
105  bs.data = buf;
106  bs.type = V_ASN1_INTEGER;
107  /* If the top bit is set the ASN.1 encoding is 1 larger. */
108  buf[0] = 0xff;
109
110  i = i2d_ASN1_INTEGER(&bs, NULL);
111  i += i; /* r and s */
112  ret = ASN1_object_size(1, i, V_ASN1_SEQUENCE);
113  BN_clear_free(order);
114  return ret;
115}
116