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 <openssl/local/cryptlib.h>
60#include <openssl/asn1t.h>
61#include <openssl/x509.h>
62#include <openssl/ec.h>
63#include <openssl/ecdsa.h>
64#include <openssl/evp.h>
65#include <openssl/local/evp_locl.h>
66
67/* EC pkey context structure */
68
69typedef struct
70	{
71	/* Key and paramgen group */
72	EC_GROUP *gen_group;
73	/* message digest */
74	const EVP_MD *md;
75	} EC_PKEY_CTX;
76
77static int pkey_ec_init(EVP_PKEY_CTX *ctx)
78	{
79	EC_PKEY_CTX *dctx;
80	dctx = OPENSSL_malloc(sizeof(EC_PKEY_CTX));
81	if (!dctx)
82		return 0;
83	dctx->gen_group = NULL;
84	dctx->md = NULL;
85
86	ctx->data = dctx;
87
88	return 1;
89	}
90
91static int pkey_ec_copy(EVP_PKEY_CTX *dst, EVP_PKEY_CTX *src)
92	{
93	EC_PKEY_CTX *dctx, *sctx;
94	if (!pkey_ec_init(dst))
95		return 0;
96       	sctx = src->data;
97	dctx = dst->data;
98	if (sctx->gen_group)
99		{
100		dctx->gen_group = EC_GROUP_dup(sctx->gen_group);
101		if (!dctx->gen_group)
102			return 0;
103		}
104	dctx->md = sctx->md;
105	return 1;
106	}
107
108static void pkey_ec_cleanup(EVP_PKEY_CTX *ctx)
109	{
110	EC_PKEY_CTX *dctx = ctx->data;
111	if (dctx)
112		{
113		if (dctx->gen_group)
114			EC_GROUP_free(dctx->gen_group);
115		OPENSSL_free(dctx);
116		}
117	}
118
119static int pkey_ec_sign(EVP_PKEY_CTX *ctx, unsigned char *sig, size_t *siglen,
120					const unsigned char *tbs, size_t tbslen)
121	{
122	int ret, type;
123	unsigned int sltmp;
124	EC_PKEY_CTX *dctx = ctx->data;
125	EC_KEY *ec = ctx->pkey->pkey.ec;
126
127	if (!sig)
128		{
129		*siglen = ECDSA_size(ec);
130		return 1;
131		}
132	else if(*siglen < (size_t)ECDSA_size(ec))
133		{
134		ECerr(EC_F_PKEY_EC_SIGN, EC_R_BUFFER_TOO_SMALL);
135		return 0;
136		}
137
138	if (dctx->md)
139		type = EVP_MD_type(dctx->md);
140	else
141		type = NID_sha1;
142
143
144	ret = ECDSA_sign(type, tbs, tbslen, sig, &sltmp, ec);
145
146	if (ret <= 0)
147		return ret;
148	*siglen = (size_t)sltmp;
149	return 1;
150	}
151
152static int pkey_ec_verify(EVP_PKEY_CTX *ctx,
153					const unsigned char *sig, size_t siglen,
154					const unsigned char *tbs, size_t tbslen)
155	{
156	int ret, type;
157	EC_PKEY_CTX *dctx = ctx->data;
158	EC_KEY *ec = ctx->pkey->pkey.ec;
159
160	if (dctx->md)
161		type = EVP_MD_type(dctx->md);
162	else
163		type = NID_sha1;
164
165	ret = ECDSA_verify(type, tbs, tbslen, sig, siglen, ec);
166
167	return ret;
168	}
169
170static int pkey_ec_derive(EVP_PKEY_CTX *ctx, unsigned char *key, size_t *keylen)
171	{
172	int ret;
173	size_t outlen;
174	const EC_POINT *pubkey = NULL;
175	if (!ctx->pkey || !ctx->peerkey)
176		{
177		ECerr(EC_F_PKEY_EC_DERIVE, EC_R_KEYS_NOT_SET);
178		return 0;
179		}
180
181	if (!key)
182		{
183		const EC_GROUP *group;
184		group = EC_KEY_get0_group(ctx->pkey->pkey.ec);
185		*keylen = (EC_GROUP_get_degree(group) + 7)/8;
186		return 1;
187		}
188
189	pubkey = EC_KEY_get0_public_key(ctx->peerkey->pkey.ec);
190
191	/* NB: unlike PKS#3 DH, if *outlen is less than maximum size this is
192	 * not an error, the result is truncated.
193	 */
194
195	outlen = *keylen;
196
197	ret = ECDH_compute_key(key, outlen, pubkey, ctx->pkey->pkey.ec, 0);
198	if (ret < 0)
199		return ret;
200	*keylen = ret;
201	return 1;
202	}
203
204static int pkey_ec_ctrl(EVP_PKEY_CTX *ctx, int type, int p1, void *p2)
205	{
206	EC_PKEY_CTX *dctx = ctx->data;
207	EC_GROUP *group;
208	switch (type)
209		{
210		case EVP_PKEY_CTRL_EC_PARAMGEN_CURVE_NID:
211		group = EC_GROUP_new_by_curve_name(p1);
212		if (group == NULL)
213			{
214			ECerr(EC_F_PKEY_EC_CTRL, EC_R_INVALID_CURVE);
215			return 0;
216			}
217		if (dctx->gen_group)
218			EC_GROUP_free(dctx->gen_group);
219		dctx->gen_group = group;
220		return 1;
221
222		case EVP_PKEY_CTRL_MD:
223		if (EVP_MD_type((const EVP_MD *)p2) != NID_sha1 &&
224		    EVP_MD_type((const EVP_MD *)p2) != NID_sha224 &&
225		    EVP_MD_type((const EVP_MD *)p2) != NID_sha256 &&
226		    EVP_MD_type((const EVP_MD *)p2) != NID_sha384 &&
227		    EVP_MD_type((const EVP_MD *)p2) != NID_sha512)
228			{
229			ECerr(EC_F_PKEY_EC_CTRL, EC_R_INVALID_DIGEST_TYPE);
230			return 0;
231			}
232		dctx->md = p2;
233		return 1;
234
235		case EVP_PKEY_CTRL_PEER_KEY:
236		/* Default behaviour is OK */
237		case EVP_PKEY_CTRL_DIGESTINIT:
238		case EVP_PKEY_CTRL_PKCS7_SIGN:
239		case EVP_PKEY_CTRL_CMS_SIGN:
240		return 1;
241
242		default:
243		return -2;
244
245		}
246	}
247
248static int pkey_ec_ctrl_str(EVP_PKEY_CTX *ctx,
249			const char *type, const char *value)
250	{
251	if (!strcmp(type, "ec_paramgen_curve"))
252		{
253		int nid;
254		nid = OBJ_sn2nid(value);
255		if (nid == NID_undef)
256			nid = OBJ_ln2nid(value);
257		if (nid == NID_undef)
258			{
259			ECerr(EC_F_PKEY_EC_CTRL_STR, EC_R_INVALID_CURVE);
260			return 0;
261			}
262		return EVP_PKEY_CTX_set_ec_paramgen_curve_nid(ctx, nid);
263		}
264	return -2;
265	}
266
267static int pkey_ec_paramgen(EVP_PKEY_CTX *ctx, EVP_PKEY *pkey)
268	{
269	EC_KEY *ec = NULL;
270	EC_PKEY_CTX *dctx = ctx->data;
271	int ret = 0;
272	if (dctx->gen_group == NULL)
273		{
274		ECerr(EC_F_PKEY_EC_PARAMGEN, EC_R_NO_PARAMETERS_SET);
275		return 0;
276		}
277	ec = EC_KEY_new();
278	if (!ec)
279		return 0;
280	ret = EC_KEY_set_group(ec, dctx->gen_group);
281	if (ret)
282		EVP_PKEY_assign_EC_KEY(pkey, ec);
283	else
284		EC_KEY_free(ec);
285	return ret;
286	}
287
288static int pkey_ec_keygen(EVP_PKEY_CTX *ctx, EVP_PKEY *pkey)
289	{
290	EC_KEY *ec = NULL;
291	if (ctx->pkey == NULL)
292		{
293		ECerr(EC_F_PKEY_EC_KEYGEN, EC_R_NO_PARAMETERS_SET);
294		return 0;
295		}
296	ec = EC_KEY_new();
297	if (!ec)
298		return 0;
299	EVP_PKEY_assign_EC_KEY(pkey, ec);
300	/* Note: if error return, pkey is freed by parent routine */
301	if (!EVP_PKEY_copy_parameters(pkey, ctx->pkey))
302		return 0;
303	return EC_KEY_generate_key(pkey->pkey.ec);
304	}
305
306const EVP_PKEY_METHOD ec_pkey_meth =
307	{
308	EVP_PKEY_EC,
309	0,
310	pkey_ec_init,
311	pkey_ec_copy,
312	pkey_ec_cleanup,
313
314	0,
315	pkey_ec_paramgen,
316
317	0,
318	pkey_ec_keygen,
319
320	0,
321	pkey_ec_sign,
322
323	0,
324	pkey_ec_verify,
325
326	0,0,
327
328	0,0,0,0,
329
330	0,0,
331
332	0,0,
333
334	0,
335	pkey_ec_derive,
336
337	pkey_ec_ctrl,
338	pkey_ec_ctrl_str
339
340	};
341