ec_print.c revision 296465 
1/* crypto/ec/ec_print.c */
2/* ====================================================================
3 * Copyright (c) 1998-2002 The OpenSSL Project.  All rights reserved.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
7 * are met:
8 *
9 * 1. Redistributions of source code must retain the above copyright
10 *    notice, this list of conditions and the following disclaimer.
11 *
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
15 *    distribution.
16 *
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/)"
21 *
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.
26 *
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.
30 *
31 * 6. Redistributions of any form whatsoever must retain the following
32 *    acknowledgment:
33 *    "This product includes software developed by the OpenSSL Project
34 *    for use in the OpenSSL Toolkit (http://www.openssl.org/)"
35 *
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 * ====================================================================
49 *
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).
53 *
54 */
55
56#include <openssl/crypto.h>
57#include "ec_lcl.h"
58
59BIGNUM *EC_POINT_point2bn(const EC_GROUP *group,
60                          const EC_POINT *point,
61                          point_conversion_form_t form,
62                          BIGNUM *ret, BN_CTX *ctx)
63{
64    size_t buf_len = 0;
65    unsigned char *buf;
66
67    buf_len = EC_POINT_point2oct(group, point, form, NULL, 0, ctx);
68    if (buf_len == 0)
69        return NULL;
70
71    if ((buf = OPENSSL_malloc(buf_len)) == NULL)
72        return NULL;
73
74    if (!EC_POINT_point2oct(group, point, form, buf, buf_len, ctx)) {
75        OPENSSL_free(buf);
76        return NULL;
77    }
78
79    ret = BN_bin2bn(buf, buf_len, ret);
80
81    OPENSSL_free(buf);
82
83    return ret;
84}
85
86EC_POINT *EC_POINT_bn2point(const EC_GROUP *group,
87                            const BIGNUM *bn, EC_POINT *point, BN_CTX *ctx)
88{
89    size_t buf_len = 0;
90    unsigned char *buf;
91    EC_POINT *ret;
92
93    if ((buf_len = BN_num_bytes(bn)) == 0)
94        return NULL;
95    buf = OPENSSL_malloc(buf_len);
96    if (buf == NULL)
97        return NULL;
98
99    if (!BN_bn2bin(bn, buf)) {
100        OPENSSL_free(buf);
101        return NULL;
102    }
103
104    if (point == NULL) {
105        if ((ret = EC_POINT_new(group)) == NULL) {
106            OPENSSL_free(buf);
107            return NULL;
108        }
109    } else
110        ret = point;
111
112    if (!EC_POINT_oct2point(group, ret, buf, buf_len, ctx)) {
113        if (point == NULL)
114            EC_POINT_clear_free(ret);
115        OPENSSL_free(buf);
116        return NULL;
117    }
118
119    OPENSSL_free(buf);
120    return ret;
121}
122
123static const char *HEX_DIGITS = "0123456789ABCDEF";
124
125/* the return value must be freed (using OPENSSL_free()) */
126char *EC_POINT_point2hex(const EC_GROUP *group,
127                         const EC_POINT *point,
128                         point_conversion_form_t form, BN_CTX *ctx)
129{
130    char *ret, *p;
131    size_t buf_len = 0, i;
132    unsigned char *buf, *pbuf;
133
134    buf_len = EC_POINT_point2oct(group, point, form, NULL, 0, ctx);
135    if (buf_len == 0)
136        return NULL;
137
138    if ((buf = OPENSSL_malloc(buf_len)) == NULL)
139        return NULL;
140
141    if (!EC_POINT_point2oct(group, point, form, buf, buf_len, ctx)) {
142        OPENSSL_free(buf);
143        return NULL;
144    }
145
146    ret = (char *)OPENSSL_malloc(buf_len * 2 + 2);
147    if (ret == NULL) {
148        OPENSSL_free(buf);
149        return NULL;
150    }
151    p = ret;
152    pbuf = buf;
153    for (i = buf_len; i > 0; i--) {
154        int v = (int)*(pbuf++);
155        *(p++) = HEX_DIGITS[v >> 4];
156        *(p++) = HEX_DIGITS[v & 0x0F];
157    }
158    *p = '\0';
159
160    OPENSSL_free(buf);
161
162    return ret;
163}
164
165EC_POINT *EC_POINT_hex2point(const EC_GROUP *group,
166                             const char *buf, EC_POINT *point, BN_CTX *ctx)
167{
168    EC_POINT *ret = NULL;
169    BIGNUM *tmp_bn = NULL;
170
171    if (!BN_hex2bn(&tmp_bn, buf))
172        return NULL;
173
174    ret = EC_POINT_bn2point(group, tmp_bn, point, ctx);
175
176    BN_clear_free(tmp_bn);
177
178    return ret;
179}
180