source: azure_iot_hub_mbedtls/trunk/mbedtls-2.16.1/library/pkwrite.c@ 398

Last change on this file since 398 was 398, checked in by coas-nagasima, 5 years ago

mbedTLS版Azure IoT Hub接続サンプルのソースコードを追加
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1/*
2 * Public Key layer for writing key files and structures
3 *
4 * Copyright (C) 2006-2015, ARM Limited, All Rights Reserved
5 * SPDX-License-Identifier: Apache-2.0
6 *
7 * Licensed under the Apache License, Version 2.0 (the "License"); you may
8 * not use this file except in compliance with the License.
9 * You may obtain a copy of the License at
10 *
11 * http://www.apache.org/licenses/LICENSE-2.0
12 *
13 * Unless required by applicable law or agreed to in writing, software
14 * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
15 * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
16 * See the License for the specific language governing permissions and
17 * limitations under the License.
18 *
19 * This file is part of mbed TLS (https://tls.mbed.org)
20 */
21
22#if !defined(MBEDTLS_CONFIG_FILE)
23#include "mbedtls/config.h"
24#else
25#include MBEDTLS_CONFIG_FILE
26#endif
27
28#if defined(MBEDTLS_PK_WRITE_C)
29
30#include "mbedtls/pk.h"
31#include "mbedtls/asn1write.h"
32#include "mbedtls/oid.h"
33#include "mbedtls/platform_util.h"
34
35#include <string.h>
36
37#if defined(MBEDTLS_RSA_C)
38#include "mbedtls/rsa.h"
39#endif
40#if defined(MBEDTLS_ECP_C)
41#include "mbedtls/ecp.h"
42#endif
43#if defined(MBEDTLS_ECDSA_C)
44#include "mbedtls/ecdsa.h"
45#endif
46#if defined(MBEDTLS_PEM_WRITE_C)
47#include "mbedtls/pem.h"
48#endif
49
50#if defined(MBEDTLS_PLATFORM_C)
51#include "mbedtls/platform.h"
52#else
53#include <stdlib.h>
54#define mbedtls_calloc calloc
55#define mbedtls_free free
56#endif
57
58/* Parameter validation macros based on platform_util.h */
59#define PK_VALIDATE_RET( cond ) \
60 MBEDTLS_INTERNAL_VALIDATE_RET( cond, MBEDTLS_ERR_PK_BAD_INPUT_DATA )
61#define PK_VALIDATE( cond ) \
62 MBEDTLS_INTERNAL_VALIDATE( cond )
63
64#if defined(MBEDTLS_RSA_C)
65/*
66 * RSAPublicKey ::= SEQUENCE {
67 * modulus INTEGER, -- n
68 * publicExponent INTEGER -- e
69 * }
70 */
71static int pk_write_rsa_pubkey( unsigned char **p, unsigned char *start,
72 mbedtls_rsa_context *rsa )
73{
74 int ret;
75 size_t len = 0;
76 mbedtls_mpi T;
77
78 mbedtls_mpi_init( &T );
79
80 /* Export E */
81 if ( ( ret = mbedtls_rsa_export( rsa, NULL, NULL, NULL, NULL, &T ) ) != 0 ||
82 ( ret = mbedtls_asn1_write_mpi( p, start, &T ) ) < 0 )
83 goto end_of_export;
84 len += ret;
85
86 /* Export N */
87 if ( ( ret = mbedtls_rsa_export( rsa, &T, NULL, NULL, NULL, NULL ) ) != 0 ||
88 ( ret = mbedtls_asn1_write_mpi( p, start, &T ) ) < 0 )
89 goto end_of_export;
90 len += ret;
91
92end_of_export:
93
94 mbedtls_mpi_free( &T );
95 if( ret < 0 )
96 return( ret );
97
98 MBEDTLS_ASN1_CHK_ADD( len, mbedtls_asn1_write_len( p, start, len ) );
99 MBEDTLS_ASN1_CHK_ADD( len, mbedtls_asn1_write_tag( p, start, MBEDTLS_ASN1_CONSTRUCTED |
100 MBEDTLS_ASN1_SEQUENCE ) );
101
102 return( (int) len );
103}
104#endif /* MBEDTLS_RSA_C */
105
106#if defined(MBEDTLS_ECP_C)
107/*
108 * EC public key is an EC point
109 */
110static int pk_write_ec_pubkey( unsigned char **p, unsigned char *start,
111 mbedtls_ecp_keypair *ec )
112{
113 int ret;
114 size_t len = 0;
115 unsigned char buf[MBEDTLS_ECP_MAX_PT_LEN];
116
117 if( ( ret = mbedtls_ecp_point_write_binary( &ec->grp, &ec->Q,
118 MBEDTLS_ECP_PF_UNCOMPRESSED,
119 &len, buf, sizeof( buf ) ) ) != 0 )
120 {
121 return( ret );
122 }
123
124 if( *p < start || (size_t)( *p - start ) < len )
125 return( MBEDTLS_ERR_ASN1_BUF_TOO_SMALL );
126
127 *p -= len;
128 memcpy( *p, buf, len );
129
130 return( (int) len );
131}
132
133/*
134 * ECParameters ::= CHOICE {
135 * namedCurve OBJECT IDENTIFIER
136 * }
137 */
138static int pk_write_ec_param( unsigned char **p, unsigned char *start,
139 mbedtls_ecp_keypair *ec )
140{
141 int ret;
142 size_t len = 0;
143 const char *oid;
144 size_t oid_len;
145
146 if( ( ret = mbedtls_oid_get_oid_by_ec_grp( ec->grp.id, &oid, &oid_len ) ) != 0 )
147 return( ret );
148
149 MBEDTLS_ASN1_CHK_ADD( len, mbedtls_asn1_write_oid( p, start, oid, oid_len ) );
150
151 return( (int) len );
152}
153#endif /* MBEDTLS_ECP_C */
154
155int mbedtls_pk_write_pubkey( unsigned char **p, unsigned char *start,
156 const mbedtls_pk_context *key )
157{
158 int ret;
159 size_t len = 0;
160
161 PK_VALIDATE_RET( p != NULL );
162 PK_VALIDATE_RET( *p != NULL );
163 PK_VALIDATE_RET( start != NULL );
164 PK_VALIDATE_RET( key != NULL );
165
166#if defined(MBEDTLS_RSA_C)
167 if( mbedtls_pk_get_type( key ) == MBEDTLS_PK_RSA )
168 MBEDTLS_ASN1_CHK_ADD( len, pk_write_rsa_pubkey( p, start, mbedtls_pk_rsa( *key ) ) );
169 else
170#endif
171#if defined(MBEDTLS_ECP_C)
172 if( mbedtls_pk_get_type( key ) == MBEDTLS_PK_ECKEY )
173 MBEDTLS_ASN1_CHK_ADD( len, pk_write_ec_pubkey( p, start, mbedtls_pk_ec( *key ) ) );
174 else
175#endif
176 return( MBEDTLS_ERR_PK_FEATURE_UNAVAILABLE );
177
178 return( (int) len );
179}
180
181int mbedtls_pk_write_pubkey_der( mbedtls_pk_context *key, unsigned char *buf, size_t size )
182{
183 int ret;
184 unsigned char *c;
185 size_t len = 0, par_len = 0, oid_len;
186 const char *oid;
187
188 PK_VALIDATE_RET( key != NULL );
189 if( size == 0 )
190 return( MBEDTLS_ERR_ASN1_BUF_TOO_SMALL );
191 PK_VALIDATE_RET( buf != NULL );
192
193 c = buf + size;
194
195 MBEDTLS_ASN1_CHK_ADD( len, mbedtls_pk_write_pubkey( &c, buf, key ) );
196
197 if( c - buf < 1 )
198 return( MBEDTLS_ERR_ASN1_BUF_TOO_SMALL );
199
200 /*
201 * SubjectPublicKeyInfo ::= SEQUENCE {
202 * algorithm AlgorithmIdentifier,
203 * subjectPublicKey BIT STRING }
204 */
205 *--c = 0;
206 len += 1;
207
208 MBEDTLS_ASN1_CHK_ADD( len, mbedtls_asn1_write_len( &c, buf, len ) );
209 MBEDTLS_ASN1_CHK_ADD( len, mbedtls_asn1_write_tag( &c, buf, MBEDTLS_ASN1_BIT_STRING ) );
210
211 if( ( ret = mbedtls_oid_get_oid_by_pk_alg( mbedtls_pk_get_type( key ),
212 &oid, &oid_len ) ) != 0 )
213 {
214 return( ret );
215 }
216
217#if defined(MBEDTLS_ECP_C)
218 if( mbedtls_pk_get_type( key ) == MBEDTLS_PK_ECKEY )
219 {
220 MBEDTLS_ASN1_CHK_ADD( par_len, pk_write_ec_param( &c, buf, mbedtls_pk_ec( *key ) ) );
221 }
222#endif
223
224 MBEDTLS_ASN1_CHK_ADD( len, mbedtls_asn1_write_algorithm_identifier( &c, buf, oid, oid_len,
225 par_len ) );
226
227 MBEDTLS_ASN1_CHK_ADD( len, mbedtls_asn1_write_len( &c, buf, len ) );
228 MBEDTLS_ASN1_CHK_ADD( len, mbedtls_asn1_write_tag( &c, buf, MBEDTLS_ASN1_CONSTRUCTED |
229 MBEDTLS_ASN1_SEQUENCE ) );
230
231 return( (int) len );
232}
233
234int mbedtls_pk_write_key_der( mbedtls_pk_context *key, unsigned char *buf, size_t size )
235{
236 int ret;
237 unsigned char *c;
238 size_t len = 0;
239
240 PK_VALIDATE_RET( key != NULL );
241 if( size == 0 )
242 return( MBEDTLS_ERR_ASN1_BUF_TOO_SMALL );
243 PK_VALIDATE_RET( buf != NULL );
244
245 c = buf + size;
246
247#if defined(MBEDTLS_RSA_C)
248 if( mbedtls_pk_get_type( key ) == MBEDTLS_PK_RSA )
249 {
250 mbedtls_mpi T; /* Temporary holding the exported parameters */
251 mbedtls_rsa_context *rsa = mbedtls_pk_rsa( *key );
252
253 /*
254 * Export the parameters one after another to avoid simultaneous copies.
255 */
256
257 mbedtls_mpi_init( &T );
258
259 /* Export QP */
260 if( ( ret = mbedtls_rsa_export_crt( rsa, NULL, NULL, &T ) ) != 0 ||
261 ( ret = mbedtls_asn1_write_mpi( &c, buf, &T ) ) < 0 )
262 goto end_of_export;
263 len += ret;
264
265 /* Export DQ */
266 if( ( ret = mbedtls_rsa_export_crt( rsa, NULL, &T, NULL ) ) != 0 ||
267 ( ret = mbedtls_asn1_write_mpi( &c, buf, &T ) ) < 0 )
268 goto end_of_export;
269 len += ret;
270
271 /* Export DP */
272 if( ( ret = mbedtls_rsa_export_crt( rsa, &T, NULL, NULL ) ) != 0 ||
273 ( ret = mbedtls_asn1_write_mpi( &c, buf, &T ) ) < 0 )
274 goto end_of_export;
275 len += ret;
276
277 /* Export Q */
278 if ( ( ret = mbedtls_rsa_export( rsa, NULL, NULL,
279 &T, NULL, NULL ) ) != 0 ||
280 ( ret = mbedtls_asn1_write_mpi( &c, buf, &T ) ) < 0 )
281 goto end_of_export;
282 len += ret;
283
284 /* Export P */
285 if ( ( ret = mbedtls_rsa_export( rsa, NULL, &T,
286 NULL, NULL, NULL ) ) != 0 ||
287 ( ret = mbedtls_asn1_write_mpi( &c, buf, &T ) ) < 0 )
288 goto end_of_export;
289 len += ret;
290
291 /* Export D */
292 if ( ( ret = mbedtls_rsa_export( rsa, NULL, NULL,
293 NULL, &T, NULL ) ) != 0 ||
294 ( ret = mbedtls_asn1_write_mpi( &c, buf, &T ) ) < 0 )
295 goto end_of_export;
296 len += ret;
297
298 /* Export E */
299 if ( ( ret = mbedtls_rsa_export( rsa, NULL, NULL,
300 NULL, NULL, &T ) ) != 0 ||
301 ( ret = mbedtls_asn1_write_mpi( &c, buf, &T ) ) < 0 )
302 goto end_of_export;
303 len += ret;
304
305 /* Export N */
306 if ( ( ret = mbedtls_rsa_export( rsa, &T, NULL,
307 NULL, NULL, NULL ) ) != 0 ||
308 ( ret = mbedtls_asn1_write_mpi( &c, buf, &T ) ) < 0 )
309 goto end_of_export;
310 len += ret;
311
312 end_of_export:
313
314 mbedtls_mpi_free( &T );
315 if( ret < 0 )
316 return( ret );
317
318 MBEDTLS_ASN1_CHK_ADD( len, mbedtls_asn1_write_int( &c, buf, 0 ) );
319 MBEDTLS_ASN1_CHK_ADD( len, mbedtls_asn1_write_len( &c, buf, len ) );
320 MBEDTLS_ASN1_CHK_ADD( len, mbedtls_asn1_write_tag( &c,
321 buf, MBEDTLS_ASN1_CONSTRUCTED |
322 MBEDTLS_ASN1_SEQUENCE ) );
323 }
324 else
325#endif /* MBEDTLS_RSA_C */
326#if defined(MBEDTLS_ECP_C)
327 if( mbedtls_pk_get_type( key ) == MBEDTLS_PK_ECKEY )
328 {
329 mbedtls_ecp_keypair *ec = mbedtls_pk_ec( *key );
330 size_t pub_len = 0, par_len = 0;
331
332 /*
333 * RFC 5915, or SEC1 Appendix C.4
334 *
335 * ECPrivateKey ::= SEQUENCE {
336 * version INTEGER { ecPrivkeyVer1(1) } (ecPrivkeyVer1),
337 * privateKey OCTET STRING,
338 * parameters [0] ECParameters {{ NamedCurve }} OPTIONAL,
339 * publicKey [1] BIT STRING OPTIONAL
340 * }
341 */
342
343 /* publicKey */
344 MBEDTLS_ASN1_CHK_ADD( pub_len, pk_write_ec_pubkey( &c, buf, ec ) );
345
346 if( c - buf < 1 )
347 return( MBEDTLS_ERR_ASN1_BUF_TOO_SMALL );
348 *--c = 0;
349 pub_len += 1;
350
351 MBEDTLS_ASN1_CHK_ADD( pub_len, mbedtls_asn1_write_len( &c, buf, pub_len ) );
352 MBEDTLS_ASN1_CHK_ADD( pub_len, mbedtls_asn1_write_tag( &c, buf, MBEDTLS_ASN1_BIT_STRING ) );
353
354 MBEDTLS_ASN1_CHK_ADD( pub_len, mbedtls_asn1_write_len( &c, buf, pub_len ) );
355 MBEDTLS_ASN1_CHK_ADD( pub_len, mbedtls_asn1_write_tag( &c, buf,
356 MBEDTLS_ASN1_CONTEXT_SPECIFIC | MBEDTLS_ASN1_CONSTRUCTED | 1 ) );
357 len += pub_len;
358
359 /* parameters */
360 MBEDTLS_ASN1_CHK_ADD( par_len, pk_write_ec_param( &c, buf, ec ) );
361
362 MBEDTLS_ASN1_CHK_ADD( par_len, mbedtls_asn1_write_len( &c, buf, par_len ) );
363 MBEDTLS_ASN1_CHK_ADD( par_len, mbedtls_asn1_write_tag( &c, buf,
364 MBEDTLS_ASN1_CONTEXT_SPECIFIC | MBEDTLS_ASN1_CONSTRUCTED | 0 ) );
365 len += par_len;
366
367 /* privateKey: write as MPI then fix tag */
368 MBEDTLS_ASN1_CHK_ADD( len, mbedtls_asn1_write_mpi( &c, buf, &ec->d ) );
369 *c = MBEDTLS_ASN1_OCTET_STRING;
370
371 /* version */
372 MBEDTLS_ASN1_CHK_ADD( len, mbedtls_asn1_write_int( &c, buf, 1 ) );
373
374 MBEDTLS_ASN1_CHK_ADD( len, mbedtls_asn1_write_len( &c, buf, len ) );
375 MBEDTLS_ASN1_CHK_ADD( len, mbedtls_asn1_write_tag( &c, buf, MBEDTLS_ASN1_CONSTRUCTED |
376 MBEDTLS_ASN1_SEQUENCE ) );
377 }
378 else
379#endif /* MBEDTLS_ECP_C */
380 return( MBEDTLS_ERR_PK_FEATURE_UNAVAILABLE );
381
382 return( (int) len );
383}
384
385#if defined(MBEDTLS_PEM_WRITE_C)
386
387#define PEM_BEGIN_PUBLIC_KEY "-----BEGIN PUBLIC KEY-----\n"
388#define PEM_END_PUBLIC_KEY "-----END PUBLIC KEY-----\n"
389
390#define PEM_BEGIN_PRIVATE_KEY_RSA "-----BEGIN RSA PRIVATE KEY-----\n"
391#define PEM_END_PRIVATE_KEY_RSA "-----END RSA PRIVATE KEY-----\n"
392#define PEM_BEGIN_PRIVATE_KEY_EC "-----BEGIN EC PRIVATE KEY-----\n"
393#define PEM_END_PRIVATE_KEY_EC "-----END EC PRIVATE KEY-----\n"
394
395/*
396 * Max sizes of key per types. Shown as tag + len (+ content).
397 */
398
399#if defined(MBEDTLS_RSA_C)
400/*
401 * RSA public keys:
402 * SubjectPublicKeyInfo ::= SEQUENCE { 1 + 3
403 * algorithm AlgorithmIdentifier, 1 + 1 (sequence)
404 * + 1 + 1 + 9 (rsa oid)
405 * + 1 + 1 (params null)
406 * subjectPublicKey BIT STRING } 1 + 3 + (1 + below)
407 * RSAPublicKey ::= SEQUENCE { 1 + 3
408 * modulus INTEGER, -- n 1 + 3 + MPI_MAX + 1
409 * publicExponent INTEGER -- e 1 + 3 + MPI_MAX + 1
410 * }
411 */
412#define RSA_PUB_DER_MAX_BYTES 38 + 2 * MBEDTLS_MPI_MAX_SIZE
413
414/*
415 * RSA private keys:
416 * RSAPrivateKey ::= SEQUENCE { 1 + 3
417 * version Version, 1 + 1 + 1
418 * modulus INTEGER, 1 + 3 + MPI_MAX + 1
419 * publicExponent INTEGER, 1 + 3 + MPI_MAX + 1
420 * privateExponent INTEGER, 1 + 3 + MPI_MAX + 1
421 * prime1 INTEGER, 1 + 3 + MPI_MAX / 2 + 1
422 * prime2 INTEGER, 1 + 3 + MPI_MAX / 2 + 1
423 * exponent1 INTEGER, 1 + 3 + MPI_MAX / 2 + 1
424 * exponent2 INTEGER, 1 + 3 + MPI_MAX / 2 + 1
425 * coefficient INTEGER, 1 + 3 + MPI_MAX / 2 + 1
426 * otherPrimeInfos OtherPrimeInfos OPTIONAL 0 (not supported)
427 * }
428 */
429#define MPI_MAX_SIZE_2 MBEDTLS_MPI_MAX_SIZE / 2 + \
430 MBEDTLS_MPI_MAX_SIZE % 2
431#define RSA_PRV_DER_MAX_BYTES 47 + 3 * MBEDTLS_MPI_MAX_SIZE \
432 + 5 * MPI_MAX_SIZE_2
433
434#else /* MBEDTLS_RSA_C */
435
436#define RSA_PUB_DER_MAX_BYTES 0
437#define RSA_PRV_DER_MAX_BYTES 0
438
439#endif /* MBEDTLS_RSA_C */
440
441#if defined(MBEDTLS_ECP_C)
442/*
443 * EC public keys:
444 * SubjectPublicKeyInfo ::= SEQUENCE { 1 + 2
445 * algorithm AlgorithmIdentifier, 1 + 1 (sequence)
446 * + 1 + 1 + 7 (ec oid)
447 * + 1 + 1 + 9 (namedCurve oid)
448 * subjectPublicKey BIT STRING 1 + 2 + 1 [1]
449 * + 1 (point format) [1]
450 * + 2 * ECP_MAX (coords) [1]
451 * }
452 */
453#define ECP_PUB_DER_MAX_BYTES 30 + 2 * MBEDTLS_ECP_MAX_BYTES
454
455/*
456 * EC private keys:
457 * ECPrivateKey ::= SEQUENCE { 1 + 2
458 * version INTEGER , 1 + 1 + 1
459 * privateKey OCTET STRING, 1 + 1 + ECP_MAX
460 * parameters [0] ECParameters OPTIONAL, 1 + 1 + (1 + 1 + 9)
461 * publicKey [1] BIT STRING OPTIONAL 1 + 2 + [1] above
462 * }
463 */
464#define ECP_PRV_DER_MAX_BYTES 29 + 3 * MBEDTLS_ECP_MAX_BYTES
465
466#else /* MBEDTLS_ECP_C */
467
468#define ECP_PUB_DER_MAX_BYTES 0
469#define ECP_PRV_DER_MAX_BYTES 0
470
471#endif /* MBEDTLS_ECP_C */
472
473#define PUB_DER_MAX_BYTES RSA_PUB_DER_MAX_BYTES > ECP_PUB_DER_MAX_BYTES ? \
474 RSA_PUB_DER_MAX_BYTES : ECP_PUB_DER_MAX_BYTES
475#define PRV_DER_MAX_BYTES RSA_PRV_DER_MAX_BYTES > ECP_PRV_DER_MAX_BYTES ? \
476 RSA_PRV_DER_MAX_BYTES : ECP_PRV_DER_MAX_BYTES
477
478int mbedtls_pk_write_pubkey_pem( mbedtls_pk_context *key, unsigned char *buf, size_t size )
479{
480 int ret;
481 unsigned char output_buf[PUB_DER_MAX_BYTES];
482 size_t olen = 0;
483
484 PK_VALIDATE_RET( key != NULL );
485 PK_VALIDATE_RET( buf != NULL || size == 0 );
486
487 if( ( ret = mbedtls_pk_write_pubkey_der( key, output_buf,
488 sizeof(output_buf) ) ) < 0 )
489 {
490 return( ret );
491 }
492
493 if( ( ret = mbedtls_pem_write_buffer( PEM_BEGIN_PUBLIC_KEY, PEM_END_PUBLIC_KEY,
494 output_buf + sizeof(output_buf) - ret,
495 ret, buf, size, &olen ) ) != 0 )
496 {
497 return( ret );
498 }
499
500 return( 0 );
501}
502
503int mbedtls_pk_write_key_pem( mbedtls_pk_context *key, unsigned char *buf, size_t size )
504{
505 int ret;
506 unsigned char output_buf[PRV_DER_MAX_BYTES];
507 const char *begin, *end;
508 size_t olen = 0;
509
510 PK_VALIDATE_RET( key != NULL );
511 PK_VALIDATE_RET( buf != NULL || size == 0 );
512
513 if( ( ret = mbedtls_pk_write_key_der( key, output_buf, sizeof(output_buf) ) ) < 0 )
514 return( ret );
515
516#if defined(MBEDTLS_RSA_C)
517 if( mbedtls_pk_get_type( key ) == MBEDTLS_PK_RSA )
518 {
519 begin = PEM_BEGIN_PRIVATE_KEY_RSA;
520 end = PEM_END_PRIVATE_KEY_RSA;
521 }
522 else
523#endif
524#if defined(MBEDTLS_ECP_C)
525 if( mbedtls_pk_get_type( key ) == MBEDTLS_PK_ECKEY )
526 {
527 begin = PEM_BEGIN_PRIVATE_KEY_EC;
528 end = PEM_END_PRIVATE_KEY_EC;
529 }
530 else
531#endif
532 return( MBEDTLS_ERR_PK_FEATURE_UNAVAILABLE );
533
534 if( ( ret = mbedtls_pem_write_buffer( begin, end,
535 output_buf + sizeof(output_buf) - ret,
536 ret, buf, size, &olen ) ) != 0 )
537 {
538 return( ret );
539 }
540
541 return( 0 );
542}
543#endif /* MBEDTLS_PEM_WRITE_C */
544
545#endif /* MBEDTLS_PK_WRITE_C */
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