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#include <openssl/evp.h>
57
58#include <string.h>
59
60#include <openssl/bn.h>
61#include <openssl/buf.h>
62#include <openssl/digest.h>
63#include <openssl/ec.h>
64#include <openssl/ec_key.h>
65#include <openssl/ecdh.h>
66#include <openssl/ecdsa.h>
67#include <openssl/err.h>
68#include <openssl/mem.h>
69#include <openssl/nid.h>
70
71#include "internal.h"
72#include "../fipsmodule/ec/internal.h"
73#include "../internal.h"
74
75
76typedef struct {
77  /* message digest */
78  const EVP_MD *md;
79} EC_PKEY_CTX;
80
81
82static int pkey_ec_init(EVP_PKEY_CTX *ctx) {
83  EC_PKEY_CTX *dctx;
84  dctx = OPENSSL_malloc(sizeof(EC_PKEY_CTX));
85  if (!dctx) {
86    return 0;
87  }
88  OPENSSL_memset(dctx, 0, sizeof(EC_PKEY_CTX));
89
90  ctx->data = dctx;
91
92  return 1;
93}
94
95static int pkey_ec_copy(EVP_PKEY_CTX *dst, EVP_PKEY_CTX *src) {
96  EC_PKEY_CTX *dctx, *sctx;
97  if (!pkey_ec_init(dst)) {
98    return 0;
99  }
100  sctx = src->data;
101  dctx = dst->data;
102
103  dctx->md = sctx->md;
104
105  return 1;
106}
107
108static void pkey_ec_cleanup(EVP_PKEY_CTX *ctx) {
109  EC_PKEY_CTX *dctx = ctx->data;
110  if (!dctx) {
111    return;
112  }
113
114  OPENSSL_free(dctx);
115}
116
117static int pkey_ec_sign(EVP_PKEY_CTX *ctx, uint8_t *sig, size_t *siglen,
118                        const uint8_t *tbs, size_t tbslen) {
119  unsigned int sltmp;
120  EC_KEY *ec = ctx->pkey->pkey.ec;
121
122  if (!sig) {
123    *siglen = ECDSA_size(ec);
124    return 1;
125  } else if (*siglen < (size_t)ECDSA_size(ec)) {
126    OPENSSL_PUT_ERROR(EVP, EVP_R_BUFFER_TOO_SMALL);
127    return 0;
128  }
129
130  if (!ECDSA_sign(0, tbs, tbslen, sig, &sltmp, ec)) {
131    return 0;
132  }
133  *siglen = (size_t)sltmp;
134  return 1;
135}
136
137static int pkey_ec_verify(EVP_PKEY_CTX *ctx, const uint8_t *sig, size_t siglen,
138                          const uint8_t *tbs, size_t tbslen) {
139  return ECDSA_verify(0, tbs, tbslen, sig, siglen, ctx->pkey->pkey.ec);
140}
141
142static int pkey_ec_derive(EVP_PKEY_CTX *ctx, uint8_t *key,
143                          size_t *keylen) {
144  int ret;
145  size_t outlen;
146  const EC_POINT *pubkey = NULL;
147  EC_KEY *eckey;
148
149  if (!ctx->pkey || !ctx->peerkey) {
150    OPENSSL_PUT_ERROR(EVP, EVP_R_KEYS_NOT_SET);
151    return 0;
152  }
153
154  eckey = ctx->pkey->pkey.ec;
155
156  if (!key) {
157    const EC_GROUP *group;
158    group = EC_KEY_get0_group(eckey);
159    *keylen = (EC_GROUP_get_degree(group) + 7) / 8;
160    return 1;
161  }
162  pubkey = EC_KEY_get0_public_key(ctx->peerkey->pkey.ec);
163
164  /* NB: unlike PKCS#3 DH, if *outlen is less than maximum size this is
165   * not an error, the result is truncated. */
166
167  outlen = *keylen;
168
169  ret = ECDH_compute_key(key, outlen, pubkey, eckey, 0);
170  if (ret < 0) {
171    return 0;
172  }
173  *keylen = ret;
174  return 1;
175}
176
177static int pkey_ec_ctrl(EVP_PKEY_CTX *ctx, int type, int p1, void *p2) {
178  EC_PKEY_CTX *dctx = ctx->data;
179
180  switch (type) {
181    case EVP_PKEY_CTRL_MD:
182      if (EVP_MD_type((const EVP_MD *)p2) != NID_sha1 &&
183          EVP_MD_type((const EVP_MD *)p2) != NID_ecdsa_with_SHA1 &&
184          EVP_MD_type((const EVP_MD *)p2) != NID_sha224 &&
185          EVP_MD_type((const EVP_MD *)p2) != NID_sha256 &&
186          EVP_MD_type((const EVP_MD *)p2) != NID_sha384 &&
187          EVP_MD_type((const EVP_MD *)p2) != NID_sha512) {
188        OPENSSL_PUT_ERROR(EVP, EVP_R_INVALID_DIGEST_TYPE);
189        return 0;
190      }
191      dctx->md = p2;
192      return 1;
193
194    case EVP_PKEY_CTRL_GET_MD:
195      *(const EVP_MD **)p2 = dctx->md;
196      return 1;
197
198    case EVP_PKEY_CTRL_PEER_KEY:
199      /* Default behaviour is OK */
200      return 1;
201
202    default:
203      OPENSSL_PUT_ERROR(EVP, EVP_R_COMMAND_NOT_SUPPORTED);
204      return 0;
205  }
206}
207
208static int pkey_ec_keygen(EVP_PKEY_CTX *ctx, EVP_PKEY *pkey) {
209  if (ctx->pkey == NULL) {
210    OPENSSL_PUT_ERROR(EVP, EVP_R_NO_PARAMETERS_SET);
211    return 0;
212  }
213  EC_KEY *ec = EC_KEY_new();
214  if (ec == NULL ||
215      !EC_KEY_set_group(ec, EC_KEY_get0_group(ctx->pkey->pkey.ec)) ||
216      !EC_KEY_generate_key(ec)) {
217    EC_KEY_free(ec);
218    return 0;
219  }
220  EVP_PKEY_assign_EC_KEY(pkey, ec);
221  return 1;
222}
223
224const EVP_PKEY_METHOD ec_pkey_meth = {
225    EVP_PKEY_EC,
226    pkey_ec_init,
227    pkey_ec_copy,
228    pkey_ec_cleanup,
229    pkey_ec_keygen,
230    pkey_ec_sign,
231    NULL /* sign_message */,
232    pkey_ec_verify,
233    NULL /* verify_message */,
234    NULL /* verify_recover */,
235    NULL /* encrypt */,
236    NULL /* decrypt */,
237    pkey_ec_derive,
238    pkey_ec_ctrl,
239};
240