ec_pmeth.c revision 279264 
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/ec.h>
63#include <openssl/ecdsa.h>
64#include <openssl/evp.h>
65#include "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
170#ifndef OPENSSL_NO_ECDH
171static int pkey_ec_derive(EVP_PKEY_CTX *ctx, unsigned char *key, size_t *keylen)
172	{
173	int ret;
174	size_t outlen;
175	const EC_POINT *pubkey = NULL;
176	if (!ctx->pkey || !ctx->peerkey)
177		{
178		ECerr(EC_F_PKEY_EC_DERIVE, EC_R_KEYS_NOT_SET);
179		return 0;
180		}
181
182	if (!key)
183		{
184		const EC_GROUP *group;
185		group = EC_KEY_get0_group(ctx->pkey->pkey.ec);
186		*keylen = (EC_GROUP_get_degree(group) + 7)/8;
187		return 1;
188		}
189
190	pubkey = EC_KEY_get0_public_key(ctx->peerkey->pkey.ec);
191
192	/* NB: unlike PKCS#3 DH, if *outlen is less than maximum size this is
193	 * not an error, the result is truncated.
194	 */
195
196	outlen = *keylen;
197
198	ret = ECDH_compute_key(key, outlen, pubkey, ctx->pkey->pkey.ec, 0);
199	if (ret < 0)
200		return ret;
201	*keylen = ret;
202	return 1;
203	}
204#endif
205
206static int pkey_ec_ctrl(EVP_PKEY_CTX *ctx, int type, int p1, void *p2)
207	{
208	EC_PKEY_CTX *dctx = ctx->data;
209	EC_GROUP *group;
210	switch (type)
211		{
212		case EVP_PKEY_CTRL_EC_PARAMGEN_CURVE_NID:
213		group = EC_GROUP_new_by_curve_name(p1);
214		if (group == NULL)
215			{
216			ECerr(EC_F_PKEY_EC_CTRL, EC_R_INVALID_CURVE);
217			return 0;
218			}
219		if (dctx->gen_group)
220			EC_GROUP_free(dctx->gen_group);
221		dctx->gen_group = group;
222		return 1;
223
224		case EVP_PKEY_CTRL_MD:
225		if (EVP_MD_type((const EVP_MD *)p2) != NID_sha1 &&
226		    EVP_MD_type((const EVP_MD *)p2) != NID_ecdsa_with_SHA1 &&
227		    EVP_MD_type((const EVP_MD *)p2) != NID_sha224 &&
228		    EVP_MD_type((const EVP_MD *)p2) != NID_sha256 &&
229		    EVP_MD_type((const EVP_MD *)p2) != NID_sha384 &&
230		    EVP_MD_type((const EVP_MD *)p2) != NID_sha512)
231			{
232			ECerr(EC_F_PKEY_EC_CTRL, EC_R_INVALID_DIGEST_TYPE);
233			return 0;
234			}
235		dctx->md = p2;
236		return 1;
237
238		case EVP_PKEY_CTRL_PEER_KEY:
239		/* Default behaviour is OK */
240		case EVP_PKEY_CTRL_DIGESTINIT:
241		case EVP_PKEY_CTRL_PKCS7_SIGN:
242		case EVP_PKEY_CTRL_CMS_SIGN:
243		return 1;
244
245		default:
246		return -2;
247
248		}
249	}
250
251static int pkey_ec_ctrl_str(EVP_PKEY_CTX *ctx,
252			const char *type, const char *value)
253	{
254	if (!strcmp(type, "ec_paramgen_curve"))
255		{
256		int nid;
257		nid = OBJ_sn2nid(value);
258		if (nid == NID_undef)
259			nid = OBJ_ln2nid(value);
260		if (nid == NID_undef)
261			{
262			ECerr(EC_F_PKEY_EC_CTRL_STR, EC_R_INVALID_CURVE);
263			return 0;
264			}
265		return EVP_PKEY_CTX_set_ec_paramgen_curve_nid(ctx, nid);
266		}
267	return -2;
268	}
269
270static int pkey_ec_paramgen(EVP_PKEY_CTX *ctx, EVP_PKEY *pkey)
271	{
272	EC_KEY *ec = NULL;
273	EC_PKEY_CTX *dctx = ctx->data;
274	int ret = 0;
275	if (dctx->gen_group == NULL)
276		{
277		ECerr(EC_F_PKEY_EC_PARAMGEN, EC_R_NO_PARAMETERS_SET);
278		return 0;
279		}
280	ec = EC_KEY_new();
281	if (!ec)
282		return 0;
283	ret = EC_KEY_set_group(ec, dctx->gen_group);
284	if (ret)
285		EVP_PKEY_assign_EC_KEY(pkey, ec);
286	else
287		EC_KEY_free(ec);
288	return ret;
289	}
290
291static int pkey_ec_keygen(EVP_PKEY_CTX *ctx, EVP_PKEY *pkey)
292	{
293	EC_KEY *ec = NULL;
294	if (ctx->pkey == NULL)
295		{
296		ECerr(EC_F_PKEY_EC_KEYGEN, EC_R_NO_PARAMETERS_SET);
297		return 0;
298		}
299	ec = EC_KEY_new();
300	if (!ec)
301		return 0;
302	EVP_PKEY_assign_EC_KEY(pkey, ec);
303	/* Note: if error return, pkey is freed by parent routine */
304	if (!EVP_PKEY_copy_parameters(pkey, ctx->pkey))
305		return 0;
306	return EC_KEY_generate_key(pkey->pkey.ec);
307	}
308
309const EVP_PKEY_METHOD ec_pkey_meth =
310	{
311	EVP_PKEY_EC,
312	0,
313	pkey_ec_init,
314	pkey_ec_copy,
315	pkey_ec_cleanup,
316
317	0,
318	pkey_ec_paramgen,
319
320	0,
321	pkey_ec_keygen,
322
323	0,
324	pkey_ec_sign,
325
326	0,
327	pkey_ec_verify,
328
329	0,0,
330
331	0,0,0,0,
332
333	0,0,
334
335	0,0,
336
337	0,
338#ifndef OPENSSL_NO_ECDH
339	pkey_ec_derive,
340#else
341	0,
342#endif
343
344	pkey_ec_ctrl,
345	pkey_ec_ctrl_str
346
347	};
348