1 /* $OpenBSD: ec_print.c,v 1.7 2014/12/03 19:53:20 deraadt 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_lcl.h"
58
59 BIGNUM *
EC_POINT_point2bn(const EC_GROUP * group,const EC_POINT * point,point_conversion_form_t form,BIGNUM * ret,BN_CTX * ctx)60 EC_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 }
84
85 EC_POINT *
EC_POINT_bn2point(const EC_GROUP * group,const BIGNUM * bn,EC_POINT * point,BN_CTX * ctx)86 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 = malloc(buf_len);
96 if (buf == NULL)
97 return NULL;
98
99 if (!BN_bn2bin(bn, buf)) {
100 free(buf);
101 return NULL;
102 }
103 if (point == NULL) {
104 if ((ret = EC_POINT_new(group)) == NULL) {
105 free(buf);
106 return NULL;
107 }
108 } else
109 ret = point;
110
111 if (!EC_POINT_oct2point(group, ret, buf, buf_len, ctx)) {
112 if (point == NULL)
113 EC_POINT_clear_free(ret);
114 free(buf);
115 return NULL;
116 }
117 free(buf);
118 return ret;
119 }
120
121 static const char *HEX_DIGITS = "0123456789ABCDEF";
122
123 /* the return value must be freed (using free()) */
124 char *
EC_POINT_point2hex(const EC_GROUP * group,const EC_POINT * point,point_conversion_form_t form,BN_CTX * ctx)125 EC_POINT_point2hex(const EC_GROUP * group, const EC_POINT * point,
126 point_conversion_form_t form, BN_CTX * ctx)
127 {
128 char *ret, *p;
129 size_t buf_len = 0, i;
130 unsigned char *buf, *pbuf;
131
132 buf_len = EC_POINT_point2oct(group, point, form,
133 NULL, 0, ctx);
134 if (buf_len == 0 || buf_len + 1 == 0)
135 return NULL;
136
137 if ((buf = malloc(buf_len)) == NULL)
138 return NULL;
139
140 if (!EC_POINT_point2oct(group, point, form, buf, buf_len, ctx)) {
141 free(buf);
142 return NULL;
143 }
144 ret = reallocarray(NULL, buf_len + 1, 2);
145 if (ret == NULL) {
146 free(buf);
147 return NULL;
148 }
149 p = ret;
150 pbuf = buf;
151 for (i = buf_len; i > 0; i--) {
152 int v = (int) *(pbuf++);
153 *(p++) = HEX_DIGITS[v >> 4];
154 *(p++) = HEX_DIGITS[v & 0x0F];
155 }
156 *p = '\0';
157
158 free(buf);
159
160 return ret;
161 }
162
163 EC_POINT *
EC_POINT_hex2point(const EC_GROUP * group,const char * buf,EC_POINT * point,BN_CTX * ctx)164 EC_POINT_hex2point(const EC_GROUP * group, const char *buf,
165 EC_POINT * point, BN_CTX * ctx)
166 {
167 EC_POINT *ret = NULL;
168 BIGNUM *tmp_bn = NULL;
169
170 if (!BN_hex2bn(&tmp_bn, buf))
171 return NULL;
172
173 ret = EC_POINT_bn2point(group, tmp_bn, point, ctx);
174
175 BN_clear_free(tmp_bn);
176
177 return ret;
178 }
179