1/* Copyright (C) 1995-1998 Eric Young (eay@cryptsoft.com)
2 * All rights reserved.
3 *
4 * This package is an SSL implementation written
5 * by Eric Young (eay@cryptsoft.com).
6 * The implementation was written so as to conform with Netscapes SSL.
7 *
8 * This library is free for commercial and non-commercial use as long as
9 * the following conditions are aheared to. The following conditions
10 * apply to all code found in this distribution, be it the RC4, RSA,
11 * lhash, DES, etc., code; not just the SSL code. The SSL documentation
12 * included with this distribution is covered by the same copyright terms
13 * except that the holder is Tim Hudson (tjh@cryptsoft.com).
14 *
15 * Copyright remains Eric Young's, and as such any Copyright notices in
16 * the code are not to be removed.
17 * If this package is used in a product, Eric Young should be given attribution
18 * as the author of the parts of the library used.
19 * This can be in the form of a textual message at program startup or
20 * in documentation (online or textual) provided with the package.
21 *
22 * Redistribution and use in source and binary forms, with or without
23 * modification, are permitted provided that the following conditions
24 * are met:
25 * 1. Redistributions of source code must retain the copyright
26 * notice, this list of conditions and the following disclaimer.
27 * 2. Redistributions in binary form must reproduce the above copyright
28 * notice, this list of conditions and the following disclaimer in the
29 * documentation and/or other materials provided with the distribution.
30 * 3. All advertising materials mentioning features or use of this software
31 * must display the following acknowledgement:
32 * "This product includes cryptographic software written by
33 * Eric Young (eay@cryptsoft.com)"
34 * The word 'cryptographic' can be left out if the rouines from the library
35 * being used are not cryptographic related :-).
36 * 4. If you include any Windows specific code (or a derivative thereof) from
37 * the apps directory (application code) you must include an acknowledgement:
38 * "This product includes software written by Tim Hudson (tjh@cryptsoft.com)"
39 *
40 * THIS SOFTWARE IS PROVIDED BY ERIC YOUNG ``AS IS'' AND
41 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
42 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
43 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
44 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
45 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
46 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
47 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
48 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
49 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
50 * SUCH DAMAGE.
51 *
52 * The licence and distribution terms for any publically available version or
53 * derivative of this code cannot be changed. i.e. this code cannot simply be
54 * copied and put under another distribution licence
55 * [including the GNU Public Licence.] */
56
57#include <openssl/evp.h>
58
59#include <string.h>
60
61#include <openssl/bytestring.h>
62#include <openssl/dsa.h>
63#include <openssl/ec_key.h>
64#include <openssl/err.h>
65#include <openssl/rsa.h>
66
67#include "internal.h"
68#include "../internal.h"
69
70
71static const EVP_PKEY_ASN1_METHOD *const kASN1Methods[] = {
72 &rsa_asn1_meth,
73 &ec_asn1_meth,
74 &dsa_asn1_meth,
75 &ed25519_asn1_meth,
76};
77
78static int parse_key_type(CBS *cbs, int *out_type) {
79 CBS oid;
80 if (!CBS_get_asn1(cbs, &oid, CBS_ASN1_OBJECT)) {
81 return 0;
82 }
83
84 for (unsigned i = 0; i < OPENSSL_ARRAY_SIZE(kASN1Methods); i++) {
85 const EVP_PKEY_ASN1_METHOD *method = kASN1Methods[i];
86 if (CBS_len(&oid) == method->oid_len &&
87 OPENSSL_memcmp(CBS_data(&oid), method->oid, method->oid_len) == 0) {
88 *out_type = method->pkey_id;
89 return 1;
90 }
91 }
92
93 return 0;
94}
95
96EVP_PKEY *EVP_parse_public_key(CBS *cbs) {
97 // Parse the SubjectPublicKeyInfo.
98 CBS spki, algorithm, key;
99 int type;
100 uint8_t padding;
101 if (!CBS_get_asn1(cbs, &spki, CBS_ASN1_SEQUENCE) ||
102 !CBS_get_asn1(&spki, &algorithm, CBS_ASN1_SEQUENCE) ||
103 !CBS_get_asn1(&spki, &key, CBS_ASN1_BITSTRING) ||
104 CBS_len(&spki) != 0) {
105 OPENSSL_PUT_ERROR(EVP, EVP_R_DECODE_ERROR);
106 return NULL;
107 }
108 if (!parse_key_type(&algorithm, &type)) {
109 OPENSSL_PUT_ERROR(EVP, EVP_R_UNSUPPORTED_ALGORITHM);
110 return NULL;
111 }
112 if (// Every key type defined encodes the key as a byte string with the same
113 // conversion to BIT STRING.
114 !CBS_get_u8(&key, &padding) ||
115 padding != 0) {
116 OPENSSL_PUT_ERROR(EVP, EVP_R_DECODE_ERROR);
117 return NULL;
118 }
119
120 // Set up an |EVP_PKEY| of the appropriate type.
121 EVP_PKEY *ret = EVP_PKEY_new();
122 if (ret == NULL ||
123 !EVP_PKEY_set_type(ret, type)) {
124 goto err;
125 }
126
127 // Call into the type-specific SPKI decoding function.
128 if (ret->ameth->pub_decode == NULL) {
129 OPENSSL_PUT_ERROR(EVP, EVP_R_UNSUPPORTED_ALGORITHM);
130 goto err;
131 }
132 if (!ret->ameth->pub_decode(ret, &algorithm, &key)) {
133 goto err;
134 }
135
136 return ret;
137
138err:
139 EVP_PKEY_free(ret);
140 return NULL;
141}
142
143int EVP_marshal_public_key(CBB *cbb, const EVP_PKEY *key) {
144 if (key->ameth == NULL || key->ameth->pub_encode == NULL) {
145 OPENSSL_PUT_ERROR(EVP, EVP_R_UNSUPPORTED_ALGORITHM);
146 return 0;
147 }
148
149 return key->ameth->pub_encode(cbb, key);
150}
151
152EVP_PKEY *EVP_parse_private_key(CBS *cbs) {
153 // Parse the PrivateKeyInfo.
154 CBS pkcs8, algorithm, key;
155 uint64_t version;
156 int type;
157 if (!CBS_get_asn1(cbs, &pkcs8, CBS_ASN1_SEQUENCE) ||
158 !CBS_get_asn1_uint64(&pkcs8, &version) ||
159 version != 0 ||
160 !CBS_get_asn1(&pkcs8, &algorithm, CBS_ASN1_SEQUENCE) ||
161 !CBS_get_asn1(&pkcs8, &key, CBS_ASN1_OCTETSTRING)) {
162 OPENSSL_PUT_ERROR(EVP, EVP_R_DECODE_ERROR);
163 return NULL;
164 }
165 if (!parse_key_type(&algorithm, &type)) {
166 OPENSSL_PUT_ERROR(EVP, EVP_R_UNSUPPORTED_ALGORITHM);
167 return NULL;
168 }
169
170 // A PrivateKeyInfo ends with a SET of Attributes which we ignore.
171
172 // Set up an |EVP_PKEY| of the appropriate type.
173 EVP_PKEY *ret = EVP_PKEY_new();
174 if (ret == NULL ||
175 !EVP_PKEY_set_type(ret, type)) {
176 goto err;
177 }
178
179 // Call into the type-specific PrivateKeyInfo decoding function.
180 if (ret->ameth->priv_decode == NULL) {
181 OPENSSL_PUT_ERROR(EVP, EVP_R_UNSUPPORTED_ALGORITHM);
182 goto err;
183 }
184 if (!ret->ameth->priv_decode(ret, &algorithm, &key)) {
185 goto err;
186 }
187
188 return ret;
189
190err:
191 EVP_PKEY_free(ret);
192 return NULL;
193}
194
195int EVP_marshal_private_key(CBB *cbb, const EVP_PKEY *key) {
196 if (key->ameth == NULL || key->ameth->priv_encode == NULL) {
197 OPENSSL_PUT_ERROR(EVP, EVP_R_UNSUPPORTED_ALGORITHM);
198 return 0;
199 }
200
201 return key->ameth->priv_encode(cbb, key);
202}
203
204static EVP_PKEY *old_priv_decode(CBS *cbs, int type) {
205 EVP_PKEY *ret = EVP_PKEY_new();
206 if (ret == NULL) {
207 return NULL;
208 }
209
210 switch (type) {
211 case EVP_PKEY_EC: {
212 EC_KEY *ec_key = EC_KEY_parse_private_key(cbs, NULL);
213 if (ec_key == NULL || !EVP_PKEY_assign_EC_KEY(ret, ec_key)) {
214 EC_KEY_free(ec_key);
215 goto err;
216 }
217 return ret;
218 }
219 case EVP_PKEY_DSA: {
220 DSA *dsa = DSA_parse_private_key(cbs);
221 if (dsa == NULL || !EVP_PKEY_assign_DSA(ret, dsa)) {
222 DSA_free(dsa);
223 goto err;
224 }
225 return ret;
226 }
227 case EVP_PKEY_RSA: {
228 RSA *rsa = RSA_parse_private_key(cbs);
229 if (rsa == NULL || !EVP_PKEY_assign_RSA(ret, rsa)) {
230 RSA_free(rsa);
231 goto err;
232 }
233 return ret;
234 }
235 default:
236 OPENSSL_PUT_ERROR(EVP, EVP_R_UNKNOWN_PUBLIC_KEY_TYPE);
237 goto err;
238 }
239
240err:
241 EVP_PKEY_free(ret);
242 return NULL;
243}
244
245EVP_PKEY *d2i_PrivateKey(int type, EVP_PKEY **out, const uint8_t **inp,
246 long len) {
247 if (len < 0) {
248 OPENSSL_PUT_ERROR(EVP, EVP_R_DECODE_ERROR);
249 return NULL;
250 }
251
252 // Parse with the legacy format.
253 CBS cbs;
254 CBS_init(&cbs, *inp, (size_t)len);
255 EVP_PKEY *ret = old_priv_decode(&cbs, type);
256 if (ret == NULL) {
257 // Try again with PKCS#8.
258 ERR_clear_error();
259 CBS_init(&cbs, *inp, (size_t)len);
260 ret = EVP_parse_private_key(&cbs);
261 if (ret == NULL) {
262 return NULL;
263 }
264 if (ret->type != type) {
265 OPENSSL_PUT_ERROR(EVP, EVP_R_DIFFERENT_KEY_TYPES);
266 EVP_PKEY_free(ret);
267 return NULL;
268 }
269 }
270
271 if (out != NULL) {
272 EVP_PKEY_free(*out);
273 *out = ret;
274 }
275 *inp = CBS_data(&cbs);
276 return ret;
277}
278
279// num_elements parses one SEQUENCE from |in| and returns the number of elements
280// in it. On parse error, it returns zero.
281static size_t num_elements(const uint8_t *in, size_t in_len) {
282 CBS cbs, sequence;
283 CBS_init(&cbs, in, (size_t)in_len);
284
285 if (!CBS_get_asn1(&cbs, &sequence, CBS_ASN1_SEQUENCE)) {
286 return 0;
287 }
288
289 size_t count = 0;
290 while (CBS_len(&sequence) > 0) {
291 if (!CBS_get_any_asn1_element(&sequence, NULL, NULL, NULL)) {
292 return 0;
293 }
294
295 count++;
296 }
297
298 return count;
299}
300
301EVP_PKEY *d2i_AutoPrivateKey(EVP_PKEY **out, const uint8_t **inp, long len) {
302 if (len < 0) {
303 OPENSSL_PUT_ERROR(EVP, EVP_R_DECODE_ERROR);
304 return NULL;
305 }
306
307 // Parse the input as a PKCS#8 PrivateKeyInfo.
308 CBS cbs;
309 CBS_init(&cbs, *inp, (size_t)len);
310 EVP_PKEY *ret = EVP_parse_private_key(&cbs);
311 if (ret != NULL) {
312 if (out != NULL) {
313 EVP_PKEY_free(*out);
314 *out = ret;
315 }
316 *inp = CBS_data(&cbs);
317 return ret;
318 }
319 ERR_clear_error();
320
321 // Count the elements to determine the legacy key format.
322 switch (num_elements(*inp, (size_t)len)) {
323 case 4:
324 return d2i_PrivateKey(EVP_PKEY_EC, out, inp, len);
325
326 case 6:
327 return d2i_PrivateKey(EVP_PKEY_DSA, out, inp, len);
328
329 default:
330 return d2i_PrivateKey(EVP_PKEY_RSA, out, inp, len);
331 }
332}
333
334int i2d_PublicKey(const EVP_PKEY *key, uint8_t **outp) {
335 switch (key->type) {
336 case EVP_PKEY_RSA:
337 return i2d_RSAPublicKey(key->pkey.rsa, outp);
338 case EVP_PKEY_DSA:
339 return i2d_DSAPublicKey(key->pkey.dsa, outp);
340 case EVP_PKEY_EC:
341 return i2o_ECPublicKey(key->pkey.ec, outp);
342 default:
343 OPENSSL_PUT_ERROR(EVP, EVP_R_UNSUPPORTED_PUBLIC_KEY_TYPE);
344 return -1;
345 }
346}
347
348EVP_PKEY *d2i_PublicKey(int type, EVP_PKEY **out, const uint8_t **inp,
349 long len) {
350 EVP_PKEY *ret = EVP_PKEY_new();
351 if (ret == NULL) {
352 return NULL;
353 }
354
355 CBS cbs;
356 CBS_init(&cbs, *inp, len < 0 ? 0 : (size_t)len);
357 switch (type) {
358 case EVP_PKEY_RSA: {
359 RSA *rsa = RSA_parse_public_key(&cbs);
360 if (rsa == NULL || !EVP_PKEY_assign_RSA(ret, rsa)) {
361 RSA_free(rsa);
362 goto err;
363 }
364 break;
365 }
366
367 // Unlike OpenSSL, we do not support EC keys with this API. The raw EC
368 // public key serialization requires knowing the group. In OpenSSL, calling
369 // this function with |EVP_PKEY_EC| and setting |out| to NULL does not work.
370 // It requires |*out| to include a partially-initiazed |EVP_PKEY| to extract
371 // the group.
372 default:
373 OPENSSL_PUT_ERROR(EVP, EVP_R_UNSUPPORTED_PUBLIC_KEY_TYPE);
374 goto err;
375 }
376
377 *inp = CBS_data(&cbs);
378 if (out != NULL) {
379 EVP_PKEY_free(*out);
380 *out = ret;
381 }
382 return ret;
383
384err:
385 EVP_PKEY_free(ret);
386 return NULL;
387}
388