1 /* Written by Dr Stephen N Henson ([email protected]) 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 * [email protected].
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 * ([email protected]). This product includes software written by Tim
54 * Hudson ([email protected]). */
55
56 #include <openssl/evp.h>
57
58 #include <openssl/bn.h>
59 #include <openssl/bytestring.h>
60 #include <openssl/ec.h>
61 #include <openssl/ec_key.h>
62 #include <openssl/ecdsa.h>
63 #include <openssl/err.h>
64
65 #include "internal.h"
66
67
eckey_pub_encode(CBB * out,const EVP_PKEY * key)68 static int eckey_pub_encode(CBB *out, const EVP_PKEY *key) {
69 const EC_KEY *ec_key = key->pkey;
70 const EC_GROUP *group = EC_KEY_get0_group(ec_key);
71 const EC_POINT *public_key = EC_KEY_get0_public_key(ec_key);
72
73 // See RFC 5480, section 2.
74 CBB spki, algorithm, oid, key_bitstring;
75 if (!CBB_add_asn1(out, &spki, CBS_ASN1_SEQUENCE) ||
76 !CBB_add_asn1(&spki, &algorithm, CBS_ASN1_SEQUENCE) ||
77 !CBB_add_asn1(&algorithm, &oid, CBS_ASN1_OBJECT) ||
78 !CBB_add_bytes(&oid, ec_asn1_meth.oid, ec_asn1_meth.oid_len) ||
79 !EC_KEY_marshal_curve_name(&algorithm, group) ||
80 !CBB_add_asn1(&spki, &key_bitstring, CBS_ASN1_BITSTRING) ||
81 !CBB_add_u8(&key_bitstring, 0 /* padding */) ||
82 !EC_POINT_point2cbb(&key_bitstring, group, public_key,
83 POINT_CONVERSION_UNCOMPRESSED, NULL) ||
84 !CBB_flush(out)) {
85 OPENSSL_PUT_ERROR(EVP, EVP_R_ENCODE_ERROR);
86 return 0;
87 }
88
89 return 1;
90 }
91
eckey_pub_decode(EVP_PKEY * out,CBS * params,CBS * key)92 static int eckey_pub_decode(EVP_PKEY *out, CBS *params, CBS *key) {
93 // See RFC 5480, section 2.
94
95 // The parameters are a named curve.
96 EC_KEY *eckey = NULL;
97 const EC_GROUP *group = EC_KEY_parse_curve_name(params);
98 if (group == NULL || CBS_len(params) != 0) {
99 OPENSSL_PUT_ERROR(EVP, EVP_R_DECODE_ERROR);
100 goto err;
101 }
102
103 eckey = EC_KEY_new();
104 if (eckey == NULL || //
105 !EC_KEY_set_group(eckey, group) ||
106 !EC_KEY_oct2key(eckey, CBS_data(key), CBS_len(key), NULL)) {
107 goto err;
108 }
109
110 EVP_PKEY_assign_EC_KEY(out, eckey);
111 return 1;
112
113 err:
114 EC_KEY_free(eckey);
115 return 0;
116 }
117
eckey_pub_cmp(const EVP_PKEY * a,const EVP_PKEY * b)118 static int eckey_pub_cmp(const EVP_PKEY *a, const EVP_PKEY *b) {
119 const EC_KEY *a_ec = a->pkey;
120 const EC_KEY *b_ec = b->pkey;
121 const EC_GROUP *group = EC_KEY_get0_group(b_ec);
122 const EC_POINT *pa = EC_KEY_get0_public_key(a_ec),
123 *pb = EC_KEY_get0_public_key(b_ec);
124 int r = EC_POINT_cmp(group, pa, pb, NULL);
125 if (r == 0) {
126 return 1;
127 } else if (r == 1) {
128 return 0;
129 } else {
130 return -2;
131 }
132 }
133
eckey_priv_decode(EVP_PKEY * out,CBS * params,CBS * key)134 static int eckey_priv_decode(EVP_PKEY *out, CBS *params, CBS *key) {
135 // See RFC 5915.
136 const EC_GROUP *group = EC_KEY_parse_parameters(params);
137 if (group == NULL || CBS_len(params) != 0) {
138 OPENSSL_PUT_ERROR(EVP, EVP_R_DECODE_ERROR);
139 return 0;
140 }
141
142 EC_KEY *ec_key = EC_KEY_parse_private_key(key, group);
143 if (ec_key == NULL || CBS_len(key) != 0) {
144 OPENSSL_PUT_ERROR(EVP, EVP_R_DECODE_ERROR);
145 EC_KEY_free(ec_key);
146 return 0;
147 }
148
149 EVP_PKEY_assign_EC_KEY(out, ec_key);
150 return 1;
151 }
152
eckey_priv_encode(CBB * out,const EVP_PKEY * key)153 static int eckey_priv_encode(CBB *out, const EVP_PKEY *key) {
154 const EC_KEY *ec_key = key->pkey;
155
156 // Omit the redundant copy of the curve name. This contradicts RFC 5915 but
157 // aligns with PKCS #11. SEC 1 only says they may be omitted if known by other
158 // means. Both OpenSSL and NSS omit the redundant parameters, so we omit them
159 // as well.
160 unsigned enc_flags = EC_KEY_get_enc_flags(ec_key) | EC_PKEY_NO_PARAMETERS;
161
162 // See RFC 5915.
163 CBB pkcs8, algorithm, oid, private_key;
164 if (!CBB_add_asn1(out, &pkcs8, CBS_ASN1_SEQUENCE) ||
165 !CBB_add_asn1_uint64(&pkcs8, 0 /* version */) ||
166 !CBB_add_asn1(&pkcs8, &algorithm, CBS_ASN1_SEQUENCE) ||
167 !CBB_add_asn1(&algorithm, &oid, CBS_ASN1_OBJECT) ||
168 !CBB_add_bytes(&oid, ec_asn1_meth.oid, ec_asn1_meth.oid_len) ||
169 !EC_KEY_marshal_curve_name(&algorithm, EC_KEY_get0_group(ec_key)) ||
170 !CBB_add_asn1(&pkcs8, &private_key, CBS_ASN1_OCTETSTRING) ||
171 !EC_KEY_marshal_private_key(&private_key, ec_key, enc_flags) ||
172 !CBB_flush(out)) {
173 OPENSSL_PUT_ERROR(EVP, EVP_R_ENCODE_ERROR);
174 return 0;
175 }
176
177 return 1;
178 }
179
eckey_set1_tls_encodedpoint(EVP_PKEY * pkey,const uint8_t * in,size_t len)180 static int eckey_set1_tls_encodedpoint(EVP_PKEY *pkey, const uint8_t *in,
181 size_t len) {
182 EC_KEY *ec_key = pkey->pkey;
183 if (ec_key == NULL) {
184 OPENSSL_PUT_ERROR(EVP, EVP_R_NO_KEY_SET);
185 return 0;
186 }
187
188 return EC_KEY_oct2key(ec_key, in, len, NULL);
189 }
190
eckey_get1_tls_encodedpoint(const EVP_PKEY * pkey,uint8_t ** out_ptr)191 static size_t eckey_get1_tls_encodedpoint(const EVP_PKEY *pkey,
192 uint8_t **out_ptr) {
193 const EC_KEY *ec_key = pkey->pkey;
194 if (ec_key == NULL) {
195 OPENSSL_PUT_ERROR(EVP, EVP_R_NO_KEY_SET);
196 return 0;
197 }
198
199 return EC_KEY_key2buf(ec_key, POINT_CONVERSION_UNCOMPRESSED, out_ptr, NULL);
200 }
201
int_ec_size(const EVP_PKEY * pkey)202 static int int_ec_size(const EVP_PKEY *pkey) {
203 const EC_KEY *ec_key = pkey->pkey;
204 return ECDSA_size(ec_key);
205 }
206
ec_bits(const EVP_PKEY * pkey)207 static int ec_bits(const EVP_PKEY *pkey) {
208 const EC_KEY *ec_key = pkey->pkey;
209 const EC_GROUP *group = EC_KEY_get0_group(ec_key);
210 if (group == NULL) {
211 ERR_clear_error();
212 return 0;
213 }
214 return EC_GROUP_order_bits(group);
215 }
216
ec_missing_parameters(const EVP_PKEY * pkey)217 static int ec_missing_parameters(const EVP_PKEY *pkey) {
218 const EC_KEY *ec_key = pkey->pkey;
219 return ec_key == NULL || EC_KEY_get0_group(ec_key) == NULL;
220 }
221
ec_copy_parameters(EVP_PKEY * to,const EVP_PKEY * from)222 static int ec_copy_parameters(EVP_PKEY *to, const EVP_PKEY *from) {
223 const EC_KEY *from_key = from->pkey;
224 if (from_key == NULL) {
225 OPENSSL_PUT_ERROR(EVP, EVP_R_NO_KEY_SET);
226 return 0;
227 }
228 const EC_GROUP *group = EC_KEY_get0_group(from_key);
229 if (group == NULL) {
230 OPENSSL_PUT_ERROR(EVP, EVP_R_MISSING_PARAMETERS);
231 return 0;
232 }
233 if (to->pkey == NULL) {
234 to->pkey = EC_KEY_new();
235 if (to->pkey == NULL) {
236 return 0;
237 }
238 }
239 return EC_KEY_set_group(to->pkey, group);
240 }
241
ec_cmp_parameters(const EVP_PKEY * a,const EVP_PKEY * b)242 static int ec_cmp_parameters(const EVP_PKEY *a, const EVP_PKEY *b) {
243 const EC_KEY *a_ec = a->pkey;
244 const EC_KEY *b_ec = b->pkey;
245 if (a_ec == NULL || b_ec == NULL) {
246 return -2;
247 }
248 const EC_GROUP *group_a = EC_KEY_get0_group(a_ec),
249 *group_b = EC_KEY_get0_group(b_ec);
250 if (group_a == NULL || group_b == NULL) {
251 return -2;
252 }
253 if (EC_GROUP_cmp(group_a, group_b, NULL) != 0) {
254 // mismatch
255 return 0;
256 }
257 return 1;
258 }
259
int_ec_free(EVP_PKEY * pkey)260 static void int_ec_free(EVP_PKEY *pkey) {
261 EC_KEY_free(pkey->pkey);
262 pkey->pkey = NULL;
263 }
264
eckey_opaque(const EVP_PKEY * pkey)265 static int eckey_opaque(const EVP_PKEY *pkey) {
266 const EC_KEY *ec_key = pkey->pkey;
267 return EC_KEY_is_opaque(ec_key);
268 }
269
270 const EVP_PKEY_ASN1_METHOD ec_asn1_meth = {
271 EVP_PKEY_EC,
272 // 1.2.840.10045.2.1
273 {0x2a, 0x86, 0x48, 0xce, 0x3d, 0x02, 0x01},
274 7,
275
276 &ec_pkey_meth,
277
278 eckey_pub_decode,
279 eckey_pub_encode,
280 eckey_pub_cmp,
281
282 eckey_priv_decode,
283 eckey_priv_encode,
284
285 /*set_priv_raw=*/NULL,
286 /*set_pub_raw=*/NULL,
287 /*get_priv_raw=*/NULL,
288 /*get_pub_raw=*/NULL,
289 eckey_set1_tls_encodedpoint,
290 eckey_get1_tls_encodedpoint,
291
292 eckey_opaque,
293
294 int_ec_size,
295 ec_bits,
296
297 ec_missing_parameters,
298 ec_copy_parameters,
299 ec_cmp_parameters,
300
301 int_ec_free,
302 };
303
EVP_PKEY_set1_EC_KEY(EVP_PKEY * pkey,EC_KEY * key)304 int EVP_PKEY_set1_EC_KEY(EVP_PKEY *pkey, EC_KEY *key) {
305 if (EVP_PKEY_assign_EC_KEY(pkey, key)) {
306 EC_KEY_up_ref(key);
307 return 1;
308 }
309 return 0;
310 }
311
EVP_PKEY_assign_EC_KEY(EVP_PKEY * pkey,EC_KEY * key)312 int EVP_PKEY_assign_EC_KEY(EVP_PKEY *pkey, EC_KEY *key) {
313 evp_pkey_set_method(pkey, &ec_asn1_meth);
314 pkey->pkey = key;
315 return key != NULL;
316 }
317
EVP_PKEY_get0_EC_KEY(const EVP_PKEY * pkey)318 EC_KEY *EVP_PKEY_get0_EC_KEY(const EVP_PKEY *pkey) {
319 if (pkey->type != EVP_PKEY_EC) {
320 OPENSSL_PUT_ERROR(EVP, EVP_R_EXPECTING_AN_EC_KEY_KEY);
321 return NULL;
322 }
323 return pkey->pkey;
324 }
325
EVP_PKEY_get1_EC_KEY(const EVP_PKEY * pkey)326 EC_KEY *EVP_PKEY_get1_EC_KEY(const EVP_PKEY *pkey) {
327 EC_KEY *ec_key = EVP_PKEY_get0_EC_KEY(pkey);
328 if (ec_key != NULL) {
329 EC_KEY_up_ref(ec_key);
330 }
331 return ec_key;
332 }
333