ec_print.c revision 1.13 
1/* $OpenBSD: ec_print.c,v 1.13 2023/07/07 13:54:45 beck Exp $ */
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_local.h"
58
59BIGNUM *
60EC_POINT_point2bn(const EC_GROUP *group, const EC_POINT *point,
61    point_conversion_form_t form, BIGNUM *ret, BN_CTX *ctx)
62{
63	size_t buf_len = 0;
64	unsigned char *buf;
65
66	buf_len = EC_POINT_point2oct(group, point, form,
67	    NULL, 0, ctx);
68	if (buf_len == 0)
69		return NULL;
70
71	if ((buf = malloc(buf_len)) == NULL)
72		return NULL;
73
74	if (!EC_POINT_point2oct(group, point, form, buf, buf_len, ctx)) {
75		free(buf);
76		return NULL;
77	}
78	ret = BN_bin2bn(buf, buf_len, ret);
79
80	free(buf);
81
82	return ret;
83}
84LCRYPTO_ALIAS(EC_POINT_point2bn);
85
86EC_POINT *
87EC_POINT_bn2point(const EC_GROUP *group,
88    const BIGNUM *bn, EC_POINT *point, BN_CTX *ctx)
89{
90	size_t buf_len = 0;
91	unsigned char *buf;
92	EC_POINT *ret;
93
94	if ((buf_len = BN_num_bytes(bn)) == 0)
95		return NULL;
96	buf = malloc(buf_len);
97	if (buf == NULL)
98		return NULL;
99
100	if (!BN_bn2bin(bn, buf)) {
101		free(buf);
102		return NULL;
103	}
104	if (point == NULL) {
105		if ((ret = EC_POINT_new(group)) == NULL) {
106			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_free(ret);
115		free(buf);
116		return NULL;
117	}
118	free(buf);
119	return ret;
120}
121LCRYPTO_ALIAS(EC_POINT_bn2point);
122
123static const char *HEX_DIGITS = "0123456789ABCDEF";
124
125/* the return value must be freed (using free()) */
126char *
127EC_POINT_point2hex(const EC_GROUP *group, 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,
135	    NULL, 0, ctx);
136	if (buf_len == 0 || buf_len + 1 == 0)
137		return NULL;
138
139	if ((buf = malloc(buf_len)) == NULL)
140		return NULL;
141
142	if (!EC_POINT_point2oct(group, point, form, buf, buf_len, ctx)) {
143		free(buf);
144		return NULL;
145	}
146	ret = reallocarray(NULL, buf_len + 1, 2);
147	if (ret == NULL) {
148		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	free(buf);
161
162	return ret;
163}
164LCRYPTO_ALIAS(EC_POINT_point2hex);
165
166EC_POINT *
167EC_POINT_hex2point(const EC_GROUP *group, const char *buf,
168    EC_POINT *point, BN_CTX *ctx)
169{
170	EC_POINT *ret = NULL;
171	BIGNUM *tmp_bn = NULL;
172
173	if (BN_hex2bn(&tmp_bn, buf) == 0)
174		return NULL;
175
176	ret = EC_POINT_bn2point(group, tmp_bn, point, ctx);
177
178	BN_free(tmp_bn);
179
180	return ret;
181}
182LCRYPTO_ALIAS(EC_POINT_hex2point);
183