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
68static 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
77static 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
86DH *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
114err:
115  OPENSSL_PUT_ERROR(DH, DH_R_DECODE_ERROR);
116  DH_free(ret);
117  return NULL;
118}
119
120int 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
134DH *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
152int 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