1 /*
2 * Copyright 2000-2016 The OpenSSL Project Authors. All Rights Reserved.
3 *
4 * Licensed under the OpenSSL license (the "License"). You may not use
5 * this file except in compliance with the License. You can obtain a copy
6 * in the file LICENSE in the source distribution or at
7 * https://www.openssl.org/source/license.html
8 */
9
10 #include <stdio.h>
11 #include "internal/cryptlib.h"
12 #include <openssl/bn.h>
13 #include "dh_local.h"
14 #include <openssl/objects.h>
15 #include <openssl/asn1t.h>
16
17 /* Override the default free and new methods */
dh_cb(int operation,ASN1_VALUE ** pval,const ASN1_ITEM * it,void * exarg)18 static int dh_cb(int operation, ASN1_VALUE **pval, const ASN1_ITEM *it,
19 void *exarg)
20 {
21 if (operation == ASN1_OP_NEW_PRE) {
22 *pval = (ASN1_VALUE *)DH_new();
23 if (*pval != NULL)
24 return 2;
25 return 0;
26 } else if (operation == ASN1_OP_FREE_PRE) {
27 DH_free((DH *)*pval);
28 *pval = NULL;
29 return 2;
30 }
31 return 1;
32 }
33
34 ASN1_SEQUENCE_cb(DHparams, dh_cb) = {
35 ASN1_SIMPLE(DH, p, BIGNUM),
36 ASN1_SIMPLE(DH, g, BIGNUM),
37 ASN1_OPT_EMBED(DH, length, ZINT32),
38 } ASN1_SEQUENCE_END_cb(DH, DHparams)
39
40 IMPLEMENT_ASN1_ENCODE_FUNCTIONS_const_fname(DH, DHparams, DHparams)
41
42 /*
43 * Internal only structures for handling X9.42 DH: this gets translated to or
44 * from a DH structure straight away.
45 */
46
47 typedef struct {
48 ASN1_BIT_STRING *seed;
49 BIGNUM *counter;
50 } int_dhvparams;
51
52 typedef struct {
53 BIGNUM *p;
54 BIGNUM *q;
55 BIGNUM *g;
56 BIGNUM *j;
57 int_dhvparams *vparams;
58 } int_dhx942_dh;
59
60 ASN1_SEQUENCE(DHvparams) = {
61 ASN1_SIMPLE(int_dhvparams, seed, ASN1_BIT_STRING),
62 ASN1_SIMPLE(int_dhvparams, counter, BIGNUM)
63 } static_ASN1_SEQUENCE_END_name(int_dhvparams, DHvparams)
64
65 ASN1_SEQUENCE(DHxparams) = {
66 ASN1_SIMPLE(int_dhx942_dh, p, BIGNUM),
67 ASN1_SIMPLE(int_dhx942_dh, g, BIGNUM),
68 ASN1_SIMPLE(int_dhx942_dh, q, BIGNUM),
69 ASN1_OPT(int_dhx942_dh, j, BIGNUM),
70 ASN1_OPT(int_dhx942_dh, vparams, DHvparams),
71 } static_ASN1_SEQUENCE_END_name(int_dhx942_dh, DHxparams)
72
73 int_dhx942_dh *d2i_int_dhx(int_dhx942_dh **a,
74 const unsigned char **pp, long length);
75 int i2d_int_dhx(const int_dhx942_dh *a, unsigned char **pp);
76
IMPLEMENT_ASN1_ENCODE_FUNCTIONS_const_fname(int_dhx942_dh,DHxparams,int_dhx)77 IMPLEMENT_ASN1_ENCODE_FUNCTIONS_const_fname(int_dhx942_dh, DHxparams, int_dhx)
78
79 /* Application public function: read in X9.42 DH parameters into DH structure */
80
81 DH *d2i_DHxparams(DH **a, const unsigned char **pp, long length)
82 {
83 int_dhx942_dh *dhx = NULL;
84 DH *dh = NULL;
85 dh = DH_new();
86 if (dh == NULL)
87 return NULL;
88 dhx = d2i_int_dhx(NULL, pp, length);
89 if (dhx == NULL) {
90 DH_free(dh);
91 return NULL;
92 }
93
94 if (a) {
95 DH_free(*a);
96 *a = dh;
97 }
98
99 dh->p = dhx->p;
100 dh->q = dhx->q;
101 dh->g = dhx->g;
102 dh->j = dhx->j;
103
104 if (dhx->vparams) {
105 dh->seed = dhx->vparams->seed->data;
106 dh->seedlen = dhx->vparams->seed->length;
107 dh->counter = dhx->vparams->counter;
108 dhx->vparams->seed->data = NULL;
109 ASN1_BIT_STRING_free(dhx->vparams->seed);
110 OPENSSL_free(dhx->vparams);
111 dhx->vparams = NULL;
112 }
113
114 OPENSSL_free(dhx);
115 return dh;
116 }
117
i2d_DHxparams(const DH * dh,unsigned char ** pp)118 int i2d_DHxparams(const DH *dh, unsigned char **pp)
119 {
120 int_dhx942_dh dhx;
121 int_dhvparams dhv;
122 ASN1_BIT_STRING bs;
123 dhx.p = dh->p;
124 dhx.g = dh->g;
125 dhx.q = dh->q;
126 dhx.j = dh->j;
127 if (dh->counter && dh->seed && dh->seedlen > 0) {
128 bs.flags = ASN1_STRING_FLAG_BITS_LEFT;
129 bs.data = dh->seed;
130 bs.length = dh->seedlen;
131 dhv.seed = &bs;
132 dhv.counter = dh->counter;
133 dhx.vparams = &dhv;
134 } else
135 dhx.vparams = NULL;
136
137 return i2d_int_dhx(&dhx, pp);
138 }
139