1/* Written by Dr Stephen N Henson (steve@openssl.org) for the OpenSSL
2 * project 2006.
3 */
4/* ====================================================================
5 * Copyright (c) 2006 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 */
57
58#include <stdio.h>
59#include "cryptlib.h"
60#include <openssl/asn1t.h>
61#include <openssl/x509.h>
62#include <openssl/evp.h>
63#include <openssl/dh.h>
64#include <openssl/bn.h>
65#include "evp_locl.h"
66
67/* DH pkey context structure */
68
69typedef struct
70	{
71	/* Parameter gen parameters */
72	int prime_len;
73	int generator;
74	int use_dsa;
75	/* Keygen callback info */
76	int gentmp[2];
77	/* message digest */
78	} DH_PKEY_CTX;
79
80static int pkey_dh_init(EVP_PKEY_CTX *ctx)
81	{
82	DH_PKEY_CTX *dctx;
83	dctx = OPENSSL_malloc(sizeof(DH_PKEY_CTX));
84	if (!dctx)
85		return 0;
86	dctx->prime_len = 1024;
87	dctx->generator = 2;
88	dctx->use_dsa = 0;
89
90	ctx->data = dctx;
91	ctx->keygen_info = dctx->gentmp;
92	ctx->keygen_info_count = 2;
93
94	return 1;
95	}
96
97static int pkey_dh_copy(EVP_PKEY_CTX *dst, EVP_PKEY_CTX *src)
98	{
99	DH_PKEY_CTX *dctx, *sctx;
100	if (!pkey_dh_init(dst))
101		return 0;
102       	sctx = src->data;
103	dctx = dst->data;
104	dctx->prime_len = sctx->prime_len;
105	dctx->generator = sctx->generator;
106	dctx->use_dsa = sctx->use_dsa;
107	return 1;
108	}
109
110static void pkey_dh_cleanup(EVP_PKEY_CTX *ctx)
111	{
112	DH_PKEY_CTX *dctx = ctx->data;
113	if (dctx)
114		OPENSSL_free(dctx);
115	}
116
117static int pkey_dh_ctrl(EVP_PKEY_CTX *ctx, int type, int p1, void *p2)
118	{
119	DH_PKEY_CTX *dctx = ctx->data;
120	switch (type)
121		{
122		case EVP_PKEY_CTRL_DH_PARAMGEN_PRIME_LEN:
123		if (p1 < 256)
124			return -2;
125		dctx->prime_len = p1;
126		return 1;
127
128		case EVP_PKEY_CTRL_DH_PARAMGEN_GENERATOR:
129		dctx->generator = p1;
130		return 1;
131
132		case EVP_PKEY_CTRL_PEER_KEY:
133		/* Default behaviour is OK */
134		return 1;
135
136		default:
137		return -2;
138
139		}
140	}
141
142
143static int pkey_dh_ctrl_str(EVP_PKEY_CTX *ctx,
144			const char *type, const char *value)
145	{
146	if (!strcmp(type, "dh_paramgen_prime_len"))
147		{
148		int len;
149		len = atoi(value);
150		return EVP_PKEY_CTX_set_dh_paramgen_prime_len(ctx, len);
151		}
152	if (!strcmp(type, "dh_paramgen_generator"))
153		{
154		int len;
155		len = atoi(value);
156		return EVP_PKEY_CTX_set_dh_paramgen_generator(ctx, len);
157		}
158	return -2;
159	}
160
161static int pkey_dh_paramgen(EVP_PKEY_CTX *ctx, EVP_PKEY *pkey)
162	{
163	DH *dh = NULL;
164	DH_PKEY_CTX *dctx = ctx->data;
165	BN_GENCB *pcb, cb;
166	int ret;
167	if (ctx->pkey_gencb)
168		{
169		pcb = &cb;
170		evp_pkey_set_cb_translate(pcb, ctx);
171		}
172	else
173		pcb = NULL;
174	dh = DH_new();
175	if (!dh)
176		return 0;
177	ret = DH_generate_parameters_ex(dh,
178					dctx->prime_len, dctx->generator, pcb);
179	if (ret)
180		EVP_PKEY_assign_DH(pkey, dh);
181	else
182		DH_free(dh);
183	return ret;
184	}
185
186static int pkey_dh_keygen(EVP_PKEY_CTX *ctx, EVP_PKEY *pkey)
187	{
188	DH *dh = NULL;
189	if (ctx->pkey == NULL)
190		{
191		DHerr(DH_F_PKEY_DH_KEYGEN, DH_R_NO_PARAMETERS_SET);
192		return 0;
193		}
194	dh = DH_new();
195	if (!dh)
196		return 0;
197	EVP_PKEY_assign_DH(pkey, dh);
198	/* Note: if error return, pkey is freed by parent routine */
199	if (!EVP_PKEY_copy_parameters(pkey, ctx->pkey))
200		return 0;
201	return DH_generate_key(pkey->pkey.dh);
202	}
203
204static int pkey_dh_derive(EVP_PKEY_CTX *ctx, unsigned char *key, size_t *keylen)
205	{
206	int ret;
207	if (!ctx->pkey || !ctx->peerkey)
208		{
209		DHerr(DH_F_PKEY_DH_DERIVE, DH_R_KEYS_NOT_SET);
210		return 0;
211		}
212	ret = DH_compute_key(key, ctx->peerkey->pkey.dh->pub_key,
213							ctx->pkey->pkey.dh);
214	if (ret < 0)
215		return ret;
216	*keylen = ret;
217	return 1;
218	}
219
220const EVP_PKEY_METHOD dh_pkey_meth =
221	{
222	EVP_PKEY_DH,
223	EVP_PKEY_FLAG_AUTOARGLEN,
224	pkey_dh_init,
225	pkey_dh_copy,
226	pkey_dh_cleanup,
227
228	0,
229	pkey_dh_paramgen,
230
231	0,
232	pkey_dh_keygen,
233
234	0,
235	0,
236
237	0,
238	0,
239
240	0,0,
241
242	0,0,0,0,
243
244	0,0,
245
246	0,0,
247
248	0,
249	pkey_dh_derive,
250
251	pkey_dh_ctrl,
252	pkey_dh_ctrl_str
253
254	};
255