1 /*
2 * Copyright 2000-2021 The OpenSSL Project Authors. All Rights Reserved.
3 *
4 * Licensed under the Apache License 2.0 (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 /*
11 * DH low level APIs are deprecated for public use, but still ok for
12 * internal use.
13 */
14 #include "internal/deprecated.h"
15
16 #include <stdio.h>
17 #include "internal/cryptlib.h"
18 #include <openssl/bn.h>
19 #include "dh_local.h"
20 #include <openssl/objects.h>
21 #include <openssl/asn1t.h>
22 #include "crypto/dh.h"
23
24 /* Override the default free and new methods */
dh_cb(int operation,ASN1_VALUE ** pval,const ASN1_ITEM * it,void * exarg)25 static int dh_cb(int operation, ASN1_VALUE **pval, const ASN1_ITEM *it,
26 void *exarg)
27 {
28 if (operation == ASN1_OP_NEW_PRE) {
29 *pval = (ASN1_VALUE *)DH_new();
30 if (*pval != NULL)
31 return 2;
32 return 0;
33 } else if (operation == ASN1_OP_FREE_PRE) {
34 DH_free((DH *)*pval);
35 *pval = NULL;
36 return 2;
37 } else if (operation == ASN1_OP_D2I_POST) {
38 DH *dh = (DH *)*pval;
39
40 DH_clear_flags(dh, DH_FLAG_TYPE_MASK);
41 DH_set_flags(dh, DH_FLAG_TYPE_DH);
42 ossl_dh_cache_named_group(dh);
43 dh->dirty_cnt++;
44 }
45 return 1;
46 }
47
48 ASN1_SEQUENCE_cb(DHparams, dh_cb) = {
49 ASN1_SIMPLE(DH, params.p, BIGNUM),
50 ASN1_SIMPLE(DH, params.g, BIGNUM),
51 ASN1_OPT_EMBED(DH, length, ZINT32),
52 } ASN1_SEQUENCE_END_cb(DH, DHparams)
53
54 IMPLEMENT_ASN1_ENCODE_FUNCTIONS_fname(DH, DHparams, DHparams)
55
56 /*
57 * Internal only structures for handling X9.42 DH: this gets translated to or
58 * from a DH structure straight away.
59 */
60
61 typedef struct {
62 ASN1_BIT_STRING *seed;
63 BIGNUM *counter;
64 } int_dhvparams;
65
66 typedef struct {
67 BIGNUM *p;
68 BIGNUM *q;
69 BIGNUM *g;
70 BIGNUM *j;
71 int_dhvparams *vparams;
72 } int_dhx942_dh;
73
74 ASN1_SEQUENCE(DHvparams) = {
75 ASN1_SIMPLE(int_dhvparams, seed, ASN1_BIT_STRING),
76 ASN1_SIMPLE(int_dhvparams, counter, BIGNUM)
77 } static_ASN1_SEQUENCE_END_name(int_dhvparams, DHvparams)
78
79 ASN1_SEQUENCE(DHxparams) = {
80 ASN1_SIMPLE(int_dhx942_dh, p, BIGNUM),
81 ASN1_SIMPLE(int_dhx942_dh, g, BIGNUM),
82 ASN1_SIMPLE(int_dhx942_dh, q, BIGNUM),
83 ASN1_OPT(int_dhx942_dh, j, BIGNUM),
84 ASN1_OPT(int_dhx942_dh, vparams, DHvparams),
85 } static_ASN1_SEQUENCE_END_name(int_dhx942_dh, DHxparams)
86
87 int_dhx942_dh *d2i_int_dhx(int_dhx942_dh **a,
88 const unsigned char **pp, long length);
89 int i2d_int_dhx(const int_dhx942_dh *a, unsigned char **pp);
90
IMPLEMENT_ASN1_ENCODE_FUNCTIONS_fname(int_dhx942_dh,DHxparams,int_dhx)91 IMPLEMENT_ASN1_ENCODE_FUNCTIONS_fname(int_dhx942_dh, DHxparams, int_dhx)
92
93 DH *d2i_DHxparams(DH **a, const unsigned char **pp, long length)
94 {
95 FFC_PARAMS *params;
96 int_dhx942_dh *dhx = NULL;
97 DH *dh = NULL;
98
99 dh = DH_new();
100 if (dh == NULL)
101 return NULL;
102 dhx = d2i_int_dhx(NULL, pp, length);
103 if (dhx == NULL) {
104 DH_free(dh);
105 return NULL;
106 }
107
108 if (a != NULL) {
109 DH_free(*a);
110 *a = dh;
111 }
112
113 params = &dh->params;
114 DH_set0_pqg(dh, dhx->p, dhx->q, dhx->g);
115 ossl_ffc_params_set0_j(params, dhx->j);
116
117 if (dhx->vparams != NULL) {
118 /* The counter has a maximum value of 4 * numbits(p) - 1 */
119 size_t counter = (size_t)BN_get_word(dhx->vparams->counter);
120 ossl_ffc_params_set_validate_params(params, dhx->vparams->seed->data,
121 dhx->vparams->seed->length,
122 counter);
123 ASN1_BIT_STRING_free(dhx->vparams->seed);
124 BN_free(dhx->vparams->counter);
125 OPENSSL_free(dhx->vparams);
126 dhx->vparams = NULL;
127 }
128
129 OPENSSL_free(dhx);
130 DH_clear_flags(dh, DH_FLAG_TYPE_MASK);
131 DH_set_flags(dh, DH_FLAG_TYPE_DHX);
132 return dh;
133 }
134
i2d_DHxparams(const DH * dh,unsigned char ** pp)135 int i2d_DHxparams(const DH *dh, unsigned char **pp)
136 {
137 int ret = 0;
138 int_dhx942_dh dhx;
139 int_dhvparams dhv = { NULL, NULL };
140 ASN1_BIT_STRING seed;
141 size_t seedlen = 0;
142 const FFC_PARAMS *params = &dh->params;
143 int counter;
144
145 ossl_ffc_params_get0_pqg(params, (const BIGNUM **)&dhx.p,
146 (const BIGNUM **)&dhx.q, (const BIGNUM **)&dhx.g);
147 dhx.j = params->j;
148 ossl_ffc_params_get_validate_params(params, &seed.data, &seedlen, &counter);
149 seed.length = (int)seedlen;
150
151 if (counter != -1 && seed.data != NULL && seed.length > 0) {
152 seed.flags = ASN1_STRING_FLAG_BITS_LEFT;
153 dhv.seed = &seed;
154 dhv.counter = BN_new();
155 if (dhv.counter == NULL)
156 return 0;
157 if (!BN_set_word(dhv.counter, (BN_ULONG)counter))
158 goto err;
159 dhx.vparams = &dhv;
160 } else {
161 dhx.vparams = NULL;
162 }
163 ret = i2d_int_dhx(&dhx, pp);
164 err:
165 BN_free(dhv.counter);
166 return ret;
167 }
168