1 /* Written by Dr Stephen N Henson (steve@openssl.org) for the OpenSSL
2 * project 2000.
3 */
4 /* ====================================================================
5 * Copyright (c) 2000-2005 The OpenSSL Project. All rights reserved.
6 *
7 * Redistribution and use in source and binary forms, with or without
8 * modification, are permitted provided that the following conditions
9 * are met:
10 *
11 * 1. Redistributions of source code must retain the above copyright
12 * notice, this list of conditions and the following disclaimer.
13 *
14 * 2. Redistributions in binary form must reproduce the above copyright
15 * notice, this list of conditions and the following disclaimer in
16 * the documentation and/or other materials provided with the
17 * distribution.
18 *
19 * 3. All advertising materials mentioning features or use of this
20 * software must display the following acknowledgment:
21 * "This product includes software developed by the OpenSSL Project
22 * for use in the OpenSSL Toolkit. (http://www.OpenSSL.org/)"
23 *
24 * 4. The names "OpenSSL Toolkit" and "OpenSSL Project" must not be used to
25 * endorse or promote products derived from this software without
26 * prior written permission. For written permission, please contact
27 * licensing@OpenSSL.org.
28 *
29 * 5. Products derived from this software may not be called "OpenSSL"
30 * nor may "OpenSSL" appear in their names without prior written
31 * permission of the OpenSSL Project.
32 *
33 * 6. Redistributions of any form whatsoever must retain the following
34 * acknowledgment:
35 * "This product includes software developed by the OpenSSL Project
36 * for use in the OpenSSL Toolkit (http://www.OpenSSL.org/)"
37 *
38 * THIS SOFTWARE IS PROVIDED BY THE OpenSSL PROJECT ``AS IS'' AND ANY
39 * EXPRESSED OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
40 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
41 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE OpenSSL PROJECT OR
42 * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
43 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
44 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
45 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
46 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
47 * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
48 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
49 * OF THE POSSIBILITY OF SUCH DAMAGE.
50 * ====================================================================
51 *
52 * This product includes cryptographic software written by Eric Young
53 * (eay@cryptsoft.com). This product includes software written by Tim
54 * Hudson (tjh@cryptsoft.com). */
55
56 #include <openssl/dh.h>
57
58 #include <assert.h>
59 #include <limits.h>
60
61 #include <openssl/bn.h>
62 #include <openssl/bytestring.h>
63 #include <openssl/err.h>
64
65 #include "../bytestring/internal.h"
66
67
parse_integer(CBS * cbs,BIGNUM ** out)68 static int parse_integer(CBS *cbs, BIGNUM **out) {
69 assert(*out == NULL);
70 *out = BN_new();
71 if (*out == NULL) {
72 return 0;
73 }
74 return BN_parse_asn1_unsigned(cbs, *out);
75 }
76
marshal_integer(CBB * cbb,BIGNUM * bn)77 static int marshal_integer(CBB *cbb, BIGNUM *bn) {
78 if (bn == NULL) {
79 // A DH object may be missing some components.
80 OPENSSL_PUT_ERROR(DH, ERR_R_PASSED_NULL_PARAMETER);
81 return 0;
82 }
83 return BN_marshal_asn1(cbb, bn);
84 }
85
DH_parse_parameters(CBS * cbs)86 DH *DH_parse_parameters(CBS *cbs) {
87 DH *ret = DH_new();
88 if (ret == NULL) {
89 return NULL;
90 }
91
92 CBS child;
93 if (!CBS_get_asn1(cbs, &child, CBS_ASN1_SEQUENCE) ||
94 !parse_integer(&child, &ret->p) ||
95 !parse_integer(&child, &ret->g)) {
96 goto err;
97 }
98
99 uint64_t priv_length;
100 if (CBS_len(&child) != 0) {
101 if (!CBS_get_asn1_uint64(&child, &priv_length) ||
102 priv_length > UINT_MAX) {
103 goto err;
104 }
105 ret->priv_length = (unsigned)priv_length;
106 }
107
108 if (CBS_len(&child) != 0) {
109 goto err;
110 }
111
112 return ret;
113
114 err:
115 OPENSSL_PUT_ERROR(DH, DH_R_DECODE_ERROR);
116 DH_free(ret);
117 return NULL;
118 }
119
DH_marshal_parameters(CBB * cbb,const DH * dh)120 int DH_marshal_parameters(CBB *cbb, const DH *dh) {
121 CBB child;
122 if (!CBB_add_asn1(cbb, &child, CBS_ASN1_SEQUENCE) ||
123 !marshal_integer(&child, dh->p) ||
124 !marshal_integer(&child, dh->g) ||
125 (dh->priv_length != 0 &&
126 !CBB_add_asn1_uint64(&child, dh->priv_length)) ||
127 !CBB_flush(cbb)) {
128 OPENSSL_PUT_ERROR(DH, DH_R_ENCODE_ERROR);
129 return 0;
130 }
131 return 1;
132 }
133
d2i_DHparams(DH ** out,const uint8_t ** inp,long len)134 DH *d2i_DHparams(DH **out, const uint8_t **inp, long len) {
135 if (len < 0) {
136 return NULL;
137 }
138 CBS cbs;
139 CBS_init(&cbs, *inp, (size_t)len);
140 DH *ret = DH_parse_parameters(&cbs);
141 if (ret == NULL) {
142 return NULL;
143 }
144 if (out != NULL) {
145 DH_free(*out);
146 *out = ret;
147 }
148 *inp = CBS_data(&cbs);
149 return ret;
150 }
151
i2d_DHparams(const DH * in,uint8_t ** outp)152 int i2d_DHparams(const DH *in, uint8_t **outp) {
153 CBB cbb;
154 if (!CBB_init(&cbb, 0) ||
155 !DH_marshal_parameters(&cbb, in)) {
156 CBB_cleanup(&cbb);
157 return -1;
158 }
159 return CBB_finish_i2d(&cbb, outp);
160 }
161