1 /*
2 * Public Key layer for writing key files and structures
3 *
4 * Copyright The Mbed TLS Contributors
5 * SPDX-License-Identifier: Apache-2.0 OR GPL-2.0-or-later
6 *
7 * This file is provided under the Apache License 2.0, or the
8 * GNU General Public License v2.0 or later.
9 *
10 * **********
11 * Apache License 2.0:
12 *
13 * Licensed under the Apache License, Version 2.0 (the "License"); you may
14 * not use this file except in compliance with the License.
15 * You may obtain a copy of the License at
16 *
17 * http://www.apache.org/licenses/LICENSE-2.0
18 *
19 * Unless required by applicable law or agreed to in writing, software
20 * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
21 * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
22 * See the License for the specific language governing permissions and
23 * limitations under the License.
24 *
25 * **********
26 *
27 * **********
28 * GNU General Public License v2.0 or later:
29 *
30 * This program is free software; you can redistribute it and/or modify
31 * it under the terms of the GNU General Public License as published by
32 * the Free Software Foundation; either version 2 of the License, or
33 * (at your option) any later version.
34 *
35 * This program is distributed in the hope that it will be useful,
36 * but WITHOUT ANY WARRANTY; without even the implied warranty of
37 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
38 * GNU General Public License for more details.
39 *
40 * You should have received a copy of the GNU General Public License along
41 * with this program; if not, write to the Free Software Foundation, Inc.,
42 * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
43 *
44 * **********
45 */
46
47 #if !defined(MBEDTLS_CONFIG_FILE)
48 #include "mbedtls/config.h"
49 #else
50 #include MBEDTLS_CONFIG_FILE
51 #endif
52
53 #if defined(MBEDTLS_PK_WRITE_C)
54
55 #include "mbedtls/pk.h"
56 #include "mbedtls/asn1write.h"
57 #include "mbedtls/oid.h"
58 #include "mbedtls/platform_util.h"
59
60 #include <string.h>
61
62 #if defined(MBEDTLS_RSA_C)
63 #include "mbedtls/rsa.h"
64 #endif
65 #if defined(MBEDTLS_ECP_C)
66 #include "mbedtls/bignum.h"
67 #include "mbedtls/ecp.h"
68 #include "mbedtls/platform_util.h"
69 #endif
70 #if defined(MBEDTLS_ECDSA_C)
71 #include "mbedtls/ecdsa.h"
72 #endif
73 #if defined(MBEDTLS_PEM_WRITE_C)
74 #include "mbedtls/pem.h"
75 #endif
76
77 #if defined(MBEDTLS_PLATFORM_C)
78 #include "mbedtls/platform.h"
79 #else
80 #include <stdlib.h>
81 #define mbedtls_calloc calloc
82 #define mbedtls_free free
83 #endif
84
85 /* Parameter validation macros based on platform_util.h */
86 #define PK_VALIDATE_RET( cond ) \
87 MBEDTLS_INTERNAL_VALIDATE_RET( cond, MBEDTLS_ERR_PK_BAD_INPUT_DATA )
88 #define PK_VALIDATE( cond ) \
89 MBEDTLS_INTERNAL_VALIDATE( cond )
90
91 #if defined(MBEDTLS_RSA_C)
92 /*
93 * RSAPublicKey ::= SEQUENCE {
94 * modulus INTEGER, -- n
95 * publicExponent INTEGER -- e
96 * }
97 */
pk_write_rsa_pubkey(unsigned char ** p,unsigned char * start,mbedtls_rsa_context * rsa)98 static int pk_write_rsa_pubkey( unsigned char **p, unsigned char *start,
99 mbedtls_rsa_context *rsa )
100 {
101 int ret;
102 size_t len = 0;
103 mbedtls_mpi T;
104
105 mbedtls_mpi_init( &T );
106
107 /* Export E */
108 if ( ( ret = mbedtls_rsa_export( rsa, NULL, NULL, NULL, NULL, &T ) ) != 0 ||
109 ( ret = mbedtls_asn1_write_mpi( p, start, &T ) ) < 0 )
110 goto end_of_export;
111 len += ret;
112
113 /* Export N */
114 if ( ( ret = mbedtls_rsa_export( rsa, &T, NULL, NULL, NULL, NULL ) ) != 0 ||
115 ( ret = mbedtls_asn1_write_mpi( p, start, &T ) ) < 0 )
116 goto end_of_export;
117 len += ret;
118
119 end_of_export:
120
121 mbedtls_mpi_free( &T );
122 if( ret < 0 )
123 return( ret );
124
125 MBEDTLS_ASN1_CHK_ADD( len, mbedtls_asn1_write_len( p, start, len ) );
126 MBEDTLS_ASN1_CHK_ADD( len, mbedtls_asn1_write_tag( p, start, MBEDTLS_ASN1_CONSTRUCTED |
127 MBEDTLS_ASN1_SEQUENCE ) );
128
129 return( (int) len );
130 }
131 #endif /* MBEDTLS_RSA_C */
132
133 #if defined(MBEDTLS_ECP_C)
134 /*
135 * EC public key is an EC point
136 */
pk_write_ec_pubkey(unsigned char ** p,unsigned char * start,mbedtls_ecp_keypair * ec)137 static int pk_write_ec_pubkey( unsigned char **p, unsigned char *start,
138 mbedtls_ecp_keypair *ec )
139 {
140 int ret;
141 size_t len = 0;
142 unsigned char buf[MBEDTLS_ECP_MAX_PT_LEN];
143
144 if( ( ret = mbedtls_ecp_point_write_binary( &ec->grp, &ec->Q,
145 MBEDTLS_ECP_PF_UNCOMPRESSED,
146 &len, buf, sizeof( buf ) ) ) != 0 )
147 {
148 return( ret );
149 }
150
151 if( *p < start || (size_t)( *p - start ) < len )
152 return( MBEDTLS_ERR_ASN1_BUF_TOO_SMALL );
153
154 *p -= len;
155 memcpy( *p, buf, len );
156
157 return( (int) len );
158 }
159
160 /*
161 * ECParameters ::= CHOICE {
162 * namedCurve OBJECT IDENTIFIER
163 * }
164 */
pk_write_ec_param(unsigned char ** p,unsigned char * start,mbedtls_ecp_keypair * ec)165 static int pk_write_ec_param( unsigned char **p, unsigned char *start,
166 mbedtls_ecp_keypair *ec )
167 {
168 int ret;
169 size_t len = 0;
170 const char *oid;
171 size_t oid_len;
172
173 if( ( ret = mbedtls_oid_get_oid_by_ec_grp( ec->grp.id, &oid, &oid_len ) ) != 0 )
174 return( ret );
175
176 MBEDTLS_ASN1_CHK_ADD( len, mbedtls_asn1_write_oid( p, start, oid, oid_len ) );
177
178 return( (int) len );
179 }
180
181 /*
182 * privateKey OCTET STRING -- always of length ceil(log2(n)/8)
183 */
pk_write_ec_private(unsigned char ** p,unsigned char * start,mbedtls_ecp_keypair * ec)184 static int pk_write_ec_private( unsigned char **p, unsigned char *start,
185 mbedtls_ecp_keypair *ec )
186 {
187 int ret;
188 size_t byte_length = ( ec->grp.pbits + 7 ) / 8;
189 unsigned char tmp[MBEDTLS_ECP_MAX_BYTES];
190
191 ret = mbedtls_mpi_write_binary( &ec->d, tmp, byte_length );
192 if( ret != 0 )
193 goto exit;
194 ret = mbedtls_asn1_write_octet_string( p, start, tmp, byte_length );
195
196 exit:
197 mbedtls_platform_zeroize( tmp, byte_length );
198 return( ret );
199 }
200 #endif /* MBEDTLS_ECP_C */
201
mbedtls_pk_write_pubkey(unsigned char ** p,unsigned char * start,const mbedtls_pk_context * key)202 int mbedtls_pk_write_pubkey( unsigned char **p, unsigned char *start,
203 const mbedtls_pk_context *key )
204 {
205 int ret;
206 size_t len = 0;
207
208 PK_VALIDATE_RET( p != NULL );
209 PK_VALIDATE_RET( *p != NULL );
210 PK_VALIDATE_RET( start != NULL );
211 PK_VALIDATE_RET( key != NULL );
212
213 #if defined(MBEDTLS_RSA_C)
214 if( mbedtls_pk_get_type( key ) == MBEDTLS_PK_RSA )
215 MBEDTLS_ASN1_CHK_ADD( len, pk_write_rsa_pubkey( p, start, mbedtls_pk_rsa( *key ) ) );
216 else
217 #endif
218 #if defined(MBEDTLS_ECP_C)
219 if( mbedtls_pk_get_type( key ) == MBEDTLS_PK_ECKEY )
220 MBEDTLS_ASN1_CHK_ADD( len, pk_write_ec_pubkey( p, start, mbedtls_pk_ec( *key ) ) );
221 else
222 #endif
223 return( MBEDTLS_ERR_PK_FEATURE_UNAVAILABLE );
224
225 return( (int) len );
226 }
227
mbedtls_pk_write_pubkey_der(mbedtls_pk_context * key,unsigned char * buf,size_t size)228 int mbedtls_pk_write_pubkey_der( mbedtls_pk_context *key, unsigned char *buf, size_t size )
229 {
230 int ret;
231 unsigned char *c;
232 size_t len = 0, par_len = 0, oid_len;
233 const char *oid;
234
235 PK_VALIDATE_RET( key != NULL );
236 if( size == 0 )
237 return( MBEDTLS_ERR_ASN1_BUF_TOO_SMALL );
238 PK_VALIDATE_RET( buf != NULL );
239
240 c = buf + size;
241
242 MBEDTLS_ASN1_CHK_ADD( len, mbedtls_pk_write_pubkey( &c, buf, key ) );
243
244 if( c - buf < 1 )
245 return( MBEDTLS_ERR_ASN1_BUF_TOO_SMALL );
246
247 /*
248 * SubjectPublicKeyInfo ::= SEQUENCE {
249 * algorithm AlgorithmIdentifier,
250 * subjectPublicKey BIT STRING }
251 */
252 *--c = 0;
253 len += 1;
254
255 MBEDTLS_ASN1_CHK_ADD( len, mbedtls_asn1_write_len( &c, buf, len ) );
256 MBEDTLS_ASN1_CHK_ADD( len, mbedtls_asn1_write_tag( &c, buf, MBEDTLS_ASN1_BIT_STRING ) );
257
258 if( ( ret = mbedtls_oid_get_oid_by_pk_alg( mbedtls_pk_get_type( key ),
259 &oid, &oid_len ) ) != 0 )
260 {
261 return( ret );
262 }
263
264 #if defined(MBEDTLS_ECP_C)
265 if( mbedtls_pk_get_type( key ) == MBEDTLS_PK_ECKEY )
266 {
267 MBEDTLS_ASN1_CHK_ADD( par_len, pk_write_ec_param( &c, buf, mbedtls_pk_ec( *key ) ) );
268 }
269 #endif
270
271 MBEDTLS_ASN1_CHK_ADD( len, mbedtls_asn1_write_algorithm_identifier( &c, buf, oid, oid_len,
272 par_len ) );
273
274 MBEDTLS_ASN1_CHK_ADD( len, mbedtls_asn1_write_len( &c, buf, len ) );
275 MBEDTLS_ASN1_CHK_ADD( len, mbedtls_asn1_write_tag( &c, buf, MBEDTLS_ASN1_CONSTRUCTED |
276 MBEDTLS_ASN1_SEQUENCE ) );
277
278 return( (int) len );
279 }
280
mbedtls_pk_write_key_der(mbedtls_pk_context * key,unsigned char * buf,size_t size)281 int mbedtls_pk_write_key_der( mbedtls_pk_context *key, unsigned char *buf, size_t size )
282 {
283 int ret;
284 unsigned char *c;
285 size_t len = 0;
286
287 PK_VALIDATE_RET( key != NULL );
288 if( size == 0 )
289 return( MBEDTLS_ERR_ASN1_BUF_TOO_SMALL );
290 PK_VALIDATE_RET( buf != NULL );
291
292 c = buf + size;
293
294 #if defined(MBEDTLS_RSA_C)
295 if( mbedtls_pk_get_type( key ) == MBEDTLS_PK_RSA )
296 {
297 mbedtls_mpi T; /* Temporary holding the exported parameters */
298 mbedtls_rsa_context *rsa = mbedtls_pk_rsa( *key );
299
300 /*
301 * Export the parameters one after another to avoid simultaneous copies.
302 */
303
304 mbedtls_mpi_init( &T );
305
306 /* Export QP */
307 if( ( ret = mbedtls_rsa_export_crt( rsa, NULL, NULL, &T ) ) != 0 ||
308 ( ret = mbedtls_asn1_write_mpi( &c, buf, &T ) ) < 0 )
309 goto end_of_export;
310 len += ret;
311
312 /* Export DQ */
313 if( ( ret = mbedtls_rsa_export_crt( rsa, NULL, &T, NULL ) ) != 0 ||
314 ( ret = mbedtls_asn1_write_mpi( &c, buf, &T ) ) < 0 )
315 goto end_of_export;
316 len += ret;
317
318 /* Export DP */
319 if( ( ret = mbedtls_rsa_export_crt( rsa, &T, NULL, NULL ) ) != 0 ||
320 ( ret = mbedtls_asn1_write_mpi( &c, buf, &T ) ) < 0 )
321 goto end_of_export;
322 len += ret;
323
324 /* Export Q */
325 if ( ( ret = mbedtls_rsa_export( rsa, NULL, NULL,
326 &T, NULL, NULL ) ) != 0 ||
327 ( ret = mbedtls_asn1_write_mpi( &c, buf, &T ) ) < 0 )
328 goto end_of_export;
329 len += ret;
330
331 /* Export P */
332 if ( ( ret = mbedtls_rsa_export( rsa, NULL, &T,
333 NULL, NULL, NULL ) ) != 0 ||
334 ( ret = mbedtls_asn1_write_mpi( &c, buf, &T ) ) < 0 )
335 goto end_of_export;
336 len += ret;
337
338 /* Export D */
339 if ( ( ret = mbedtls_rsa_export( rsa, NULL, NULL,
340 NULL, &T, NULL ) ) != 0 ||
341 ( ret = mbedtls_asn1_write_mpi( &c, buf, &T ) ) < 0 )
342 goto end_of_export;
343 len += ret;
344
345 /* Export E */
346 if ( ( ret = mbedtls_rsa_export( rsa, NULL, NULL,
347 NULL, NULL, &T ) ) != 0 ||
348 ( ret = mbedtls_asn1_write_mpi( &c, buf, &T ) ) < 0 )
349 goto end_of_export;
350 len += ret;
351
352 /* Export N */
353 if ( ( ret = mbedtls_rsa_export( rsa, &T, NULL,
354 NULL, NULL, NULL ) ) != 0 ||
355 ( ret = mbedtls_asn1_write_mpi( &c, buf, &T ) ) < 0 )
356 goto end_of_export;
357 len += ret;
358
359 end_of_export:
360
361 mbedtls_mpi_free( &T );
362 if( ret < 0 )
363 return( ret );
364
365 MBEDTLS_ASN1_CHK_ADD( len, mbedtls_asn1_write_int( &c, buf, 0 ) );
366 MBEDTLS_ASN1_CHK_ADD( len, mbedtls_asn1_write_len( &c, buf, len ) );
367 MBEDTLS_ASN1_CHK_ADD( len, mbedtls_asn1_write_tag( &c,
368 buf, MBEDTLS_ASN1_CONSTRUCTED |
369 MBEDTLS_ASN1_SEQUENCE ) );
370 }
371 else
372 #endif /* MBEDTLS_RSA_C */
373 #if defined(MBEDTLS_ECP_C)
374 if( mbedtls_pk_get_type( key ) == MBEDTLS_PK_ECKEY )
375 {
376 mbedtls_ecp_keypair *ec = mbedtls_pk_ec( *key );
377 size_t pub_len = 0, par_len = 0;
378
379 /*
380 * RFC 5915, or SEC1 Appendix C.4
381 *
382 * ECPrivateKey ::= SEQUENCE {
383 * version INTEGER { ecPrivkeyVer1(1) } (ecPrivkeyVer1),
384 * privateKey OCTET STRING,
385 * parameters [0] ECParameters {{ NamedCurve }} OPTIONAL,
386 * publicKey [1] BIT STRING OPTIONAL
387 * }
388 */
389
390 /* publicKey */
391 MBEDTLS_ASN1_CHK_ADD( pub_len, pk_write_ec_pubkey( &c, buf, ec ) );
392
393 if( c - buf < 1 )
394 return( MBEDTLS_ERR_ASN1_BUF_TOO_SMALL );
395 *--c = 0;
396 pub_len += 1;
397
398 MBEDTLS_ASN1_CHK_ADD( pub_len, mbedtls_asn1_write_len( &c, buf, pub_len ) );
399 MBEDTLS_ASN1_CHK_ADD( pub_len, mbedtls_asn1_write_tag( &c, buf, MBEDTLS_ASN1_BIT_STRING ) );
400
401 MBEDTLS_ASN1_CHK_ADD( pub_len, mbedtls_asn1_write_len( &c, buf, pub_len ) );
402 MBEDTLS_ASN1_CHK_ADD( pub_len, mbedtls_asn1_write_tag( &c, buf,
403 MBEDTLS_ASN1_CONTEXT_SPECIFIC | MBEDTLS_ASN1_CONSTRUCTED | 1 ) );
404 len += pub_len;
405
406 /* parameters */
407 MBEDTLS_ASN1_CHK_ADD( par_len, pk_write_ec_param( &c, buf, ec ) );
408
409 MBEDTLS_ASN1_CHK_ADD( par_len, mbedtls_asn1_write_len( &c, buf, par_len ) );
410 MBEDTLS_ASN1_CHK_ADD( par_len, mbedtls_asn1_write_tag( &c, buf,
411 MBEDTLS_ASN1_CONTEXT_SPECIFIC | MBEDTLS_ASN1_CONSTRUCTED | 0 ) );
412 len += par_len;
413
414 /* privateKey */
415 MBEDTLS_ASN1_CHK_ADD( len, pk_write_ec_private( &c, buf, ec ) );
416
417 /* version */
418 MBEDTLS_ASN1_CHK_ADD( len, mbedtls_asn1_write_int( &c, buf, 1 ) );
419
420 MBEDTLS_ASN1_CHK_ADD( len, mbedtls_asn1_write_len( &c, buf, len ) );
421 MBEDTLS_ASN1_CHK_ADD( len, mbedtls_asn1_write_tag( &c, buf, MBEDTLS_ASN1_CONSTRUCTED |
422 MBEDTLS_ASN1_SEQUENCE ) );
423 }
424 else
425 #endif /* MBEDTLS_ECP_C */
426 return( MBEDTLS_ERR_PK_FEATURE_UNAVAILABLE );
427
428 return( (int) len );
429 }
430
431 #if defined(MBEDTLS_PEM_WRITE_C)
432
433 #define PEM_BEGIN_PUBLIC_KEY "-----BEGIN PUBLIC KEY-----\n"
434 #define PEM_END_PUBLIC_KEY "-----END PUBLIC KEY-----\n"
435
436 #define PEM_BEGIN_PRIVATE_KEY_RSA "-----BEGIN RSA PRIVATE KEY-----\n"
437 #define PEM_END_PRIVATE_KEY_RSA "-----END RSA PRIVATE KEY-----\n"
438 #define PEM_BEGIN_PRIVATE_KEY_EC "-----BEGIN EC PRIVATE KEY-----\n"
439 #define PEM_END_PRIVATE_KEY_EC "-----END EC PRIVATE KEY-----\n"
440
441 /*
442 * Max sizes of key per types. Shown as tag + len (+ content).
443 */
444
445 #if defined(MBEDTLS_RSA_C)
446 /*
447 * RSA public keys:
448 * SubjectPublicKeyInfo ::= SEQUENCE { 1 + 3
449 * algorithm AlgorithmIdentifier, 1 + 1 (sequence)
450 * + 1 + 1 + 9 (rsa oid)
451 * + 1 + 1 (params null)
452 * subjectPublicKey BIT STRING } 1 + 3 + (1 + below)
453 * RSAPublicKey ::= SEQUENCE { 1 + 3
454 * modulus INTEGER, -- n 1 + 3 + MPI_MAX + 1
455 * publicExponent INTEGER -- e 1 + 3 + MPI_MAX + 1
456 * }
457 */
458 #define RSA_PUB_DER_MAX_BYTES ( 38 + 2 * MBEDTLS_MPI_MAX_SIZE )
459
460 /*
461 * RSA private keys:
462 * RSAPrivateKey ::= SEQUENCE { 1 + 3
463 * version Version, 1 + 1 + 1
464 * modulus INTEGER, 1 + 3 + MPI_MAX + 1
465 * publicExponent INTEGER, 1 + 3 + MPI_MAX + 1
466 * privateExponent INTEGER, 1 + 3 + MPI_MAX + 1
467 * prime1 INTEGER, 1 + 3 + MPI_MAX / 2 + 1
468 * prime2 INTEGER, 1 + 3 + MPI_MAX / 2 + 1
469 * exponent1 INTEGER, 1 + 3 + MPI_MAX / 2 + 1
470 * exponent2 INTEGER, 1 + 3 + MPI_MAX / 2 + 1
471 * coefficient INTEGER, 1 + 3 + MPI_MAX / 2 + 1
472 * otherPrimeInfos OtherPrimeInfos OPTIONAL 0 (not supported)
473 * }
474 */
475 #define MPI_MAX_SIZE_2 ( MBEDTLS_MPI_MAX_SIZE / 2 + \
476 MBEDTLS_MPI_MAX_SIZE % 2 )
477 #define RSA_PRV_DER_MAX_BYTES ( 47 + 3 * MBEDTLS_MPI_MAX_SIZE \
478 + 5 * MPI_MAX_SIZE_2 )
479
480 #else /* MBEDTLS_RSA_C */
481
482 #define RSA_PUB_DER_MAX_BYTES 0
483 #define RSA_PRV_DER_MAX_BYTES 0
484
485 #endif /* MBEDTLS_RSA_C */
486
487 #if defined(MBEDTLS_ECP_C)
488 /*
489 * EC public keys:
490 * SubjectPublicKeyInfo ::= SEQUENCE { 1 + 2
491 * algorithm AlgorithmIdentifier, 1 + 1 (sequence)
492 * + 1 + 1 + 7 (ec oid)
493 * + 1 + 1 + 9 (namedCurve oid)
494 * subjectPublicKey BIT STRING 1 + 2 + 1 [1]
495 * + 1 (point format) [1]
496 * + 2 * ECP_MAX (coords) [1]
497 * }
498 */
499 #define ECP_PUB_DER_MAX_BYTES ( 30 + 2 * MBEDTLS_ECP_MAX_BYTES )
500
501 /*
502 * EC private keys:
503 * ECPrivateKey ::= SEQUENCE { 1 + 2
504 * version INTEGER , 1 + 1 + 1
505 * privateKey OCTET STRING, 1 + 1 + ECP_MAX
506 * parameters [0] ECParameters OPTIONAL, 1 + 1 + (1 + 1 + 9)
507 * publicKey [1] BIT STRING OPTIONAL 1 + 2 + [1] above
508 * }
509 */
510 #define ECP_PRV_DER_MAX_BYTES ( 29 + 3 * MBEDTLS_ECP_MAX_BYTES )
511
512 #else /* MBEDTLS_ECP_C */
513
514 #define ECP_PUB_DER_MAX_BYTES 0
515 #define ECP_PRV_DER_MAX_BYTES 0
516
517 #endif /* MBEDTLS_ECP_C */
518
519 #define PUB_DER_MAX_BYTES ( RSA_PUB_DER_MAX_BYTES > ECP_PUB_DER_MAX_BYTES ? \
520 RSA_PUB_DER_MAX_BYTES : ECP_PUB_DER_MAX_BYTES )
521 #define PRV_DER_MAX_BYTES ( RSA_PRV_DER_MAX_BYTES > ECP_PRV_DER_MAX_BYTES ? \
522 RSA_PRV_DER_MAX_BYTES : ECP_PRV_DER_MAX_BYTES )
523
mbedtls_pk_write_pubkey_pem(mbedtls_pk_context * key,unsigned char * buf,size_t size)524 int mbedtls_pk_write_pubkey_pem( mbedtls_pk_context *key, unsigned char *buf, size_t size )
525 {
526 int ret;
527 unsigned char output_buf[PUB_DER_MAX_BYTES];
528 size_t olen = 0;
529
530 PK_VALIDATE_RET( key != NULL );
531 PK_VALIDATE_RET( buf != NULL || size == 0 );
532
533 if( ( ret = mbedtls_pk_write_pubkey_der( key, output_buf,
534 sizeof(output_buf) ) ) < 0 )
535 {
536 return( ret );
537 }
538
539 if( ( ret = mbedtls_pem_write_buffer( PEM_BEGIN_PUBLIC_KEY, PEM_END_PUBLIC_KEY,
540 output_buf + sizeof(output_buf) - ret,
541 ret, buf, size, &olen ) ) != 0 )
542 {
543 return( ret );
544 }
545
546 return( 0 );
547 }
548
mbedtls_pk_write_key_pem(mbedtls_pk_context * key,unsigned char * buf,size_t size)549 int mbedtls_pk_write_key_pem( mbedtls_pk_context *key, unsigned char *buf, size_t size )
550 {
551 int ret;
552 unsigned char output_buf[PRV_DER_MAX_BYTES];
553 const char *begin, *end;
554 size_t olen = 0;
555
556 PK_VALIDATE_RET( key != NULL );
557 PK_VALIDATE_RET( buf != NULL || size == 0 );
558
559 if( ( ret = mbedtls_pk_write_key_der( key, output_buf, sizeof(output_buf) ) ) < 0 )
560 return( ret );
561
562 #if defined(MBEDTLS_RSA_C)
563 if( mbedtls_pk_get_type( key ) == MBEDTLS_PK_RSA )
564 {
565 begin = PEM_BEGIN_PRIVATE_KEY_RSA;
566 end = PEM_END_PRIVATE_KEY_RSA;
567 }
568 else
569 #endif
570 #if defined(MBEDTLS_ECP_C)
571 if( mbedtls_pk_get_type( key ) == MBEDTLS_PK_ECKEY )
572 {
573 begin = PEM_BEGIN_PRIVATE_KEY_EC;
574 end = PEM_END_PRIVATE_KEY_EC;
575 }
576 else
577 #endif
578 return( MBEDTLS_ERR_PK_FEATURE_UNAVAILABLE );
579
580 if( ( ret = mbedtls_pem_write_buffer( begin, end,
581 output_buf + sizeof(output_buf) - ret,
582 ret, buf, size, &olen ) ) != 0 )
583 {
584 return( ret );
585 }
586
587 return( 0 );
588 }
589 #endif /* MBEDTLS_PEM_WRITE_C */
590
591 #endif /* MBEDTLS_PK_WRITE_C */
592