1 /*
2 * Public Key layer for parsing key files and structures
3 *
4 * Copyright The Mbed TLS Contributors
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
20 #include "common.h"
21
22 #if defined(MBEDTLS_PK_PARSE_C)
23
24 #include "mbedtls/pk.h"
25 #include "mbedtls/asn1.h"
26 #include "mbedtls/oid.h"
27 #include "mbedtls/platform_util.h"
28 #include "mbedtls/error.h"
29
30 #include <string.h>
31
32 #if defined(MBEDTLS_RSA_C)
33 #include "mbedtls/rsa.h"
34 #endif
35 #if defined(MBEDTLS_ECP_C)
36 #include "mbedtls/ecp.h"
37 #endif
38 #if defined(MBEDTLS_ECDSA_C)
39 #include "mbedtls/ecdsa.h"
40 #endif
41 #if defined(MBEDTLS_PEM_PARSE_C)
42 #include "mbedtls/pem.h"
43 #endif
44 #if defined(MBEDTLS_PKCS5_C)
45 #include "mbedtls/pkcs5.h"
46 #endif
47 #if defined(MBEDTLS_PKCS12_C)
48 #include "mbedtls/pkcs12.h"
49 #endif
50
51 #include "mbedtls/platform.h"
52
53 #if defined(MBEDTLS_FS_IO)
54 /*
55 * Load all data from a file into a given buffer.
56 *
57 * The file is expected to contain either PEM or DER encoded data.
58 * A terminating null byte is always appended. It is included in the announced
59 * length only if the data looks like it is PEM encoded.
60 */
mbedtls_pk_load_file(const char * path,unsigned char ** buf,size_t * n)61 int mbedtls_pk_load_file( const char *path, unsigned char **buf, size_t *n )
62 {
63 FILE *f;
64 long size;
65
66 if( ( f = fopen( path, "rb" ) ) == NULL )
67 return( MBEDTLS_ERR_PK_FILE_IO_ERROR );
68
69 /* Ensure no stdio buffering of secrets, as such buffers cannot be wiped. */
70 mbedtls_setbuf( f, NULL );
71
72 fseek( f, 0, SEEK_END );
73 if( ( size = ftell( f ) ) == -1 )
74 {
75 fclose( f );
76 return( MBEDTLS_ERR_PK_FILE_IO_ERROR );
77 }
78 fseek( f, 0, SEEK_SET );
79
80 *n = (size_t) size;
81
82 if( *n + 1 == 0 ||
83 ( *buf = mbedtls_calloc( 1, *n + 1 ) ) == NULL )
84 {
85 fclose( f );
86 return( MBEDTLS_ERR_PK_ALLOC_FAILED );
87 }
88
89 if( fread( *buf, 1, *n, f ) != *n )
90 {
91 fclose( f );
92
93 mbedtls_platform_zeroize( *buf, *n );
94 mbedtls_free( *buf );
95
96 return( MBEDTLS_ERR_PK_FILE_IO_ERROR );
97 }
98
99 fclose( f );
100
101 (*buf)[*n] = '\0';
102
103 if( strstr( (const char *) *buf, "-----BEGIN " ) != NULL )
104 ++*n;
105
106 return( 0 );
107 }
108
109 /*
110 * Load and parse a private key
111 */
mbedtls_pk_parse_keyfile(mbedtls_pk_context * ctx,const char * path,const char * pwd,int (* f_rng)(void *,unsigned char *,size_t),void * p_rng)112 int mbedtls_pk_parse_keyfile( mbedtls_pk_context *ctx,
113 const char *path, const char *pwd,
114 int (*f_rng)(void *, unsigned char *, size_t), void *p_rng )
115 {
116 int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
117 size_t n;
118 unsigned char *buf;
119
120 if( ( ret = mbedtls_pk_load_file( path, &buf, &n ) ) != 0 )
121 return( ret );
122
123 if( pwd == NULL )
124 ret = mbedtls_pk_parse_key( ctx, buf, n, NULL, 0, f_rng, p_rng );
125 else
126 ret = mbedtls_pk_parse_key( ctx, buf, n,
127 (const unsigned char *) pwd, strlen( pwd ), f_rng, p_rng );
128
129 mbedtls_platform_zeroize( buf, n );
130 mbedtls_free( buf );
131
132 return( ret );
133 }
134
135 /*
136 * Load and parse a public key
137 */
mbedtls_pk_parse_public_keyfile(mbedtls_pk_context * ctx,const char * path)138 int mbedtls_pk_parse_public_keyfile( mbedtls_pk_context *ctx, const char *path )
139 {
140 int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
141 size_t n;
142 unsigned char *buf;
143
144 if( ( ret = mbedtls_pk_load_file( path, &buf, &n ) ) != 0 )
145 return( ret );
146
147 ret = mbedtls_pk_parse_public_key( ctx, buf, n );
148
149 mbedtls_platform_zeroize( buf, n );
150 mbedtls_free( buf );
151
152 return( ret );
153 }
154 #endif /* MBEDTLS_FS_IO */
155
156 #if defined(MBEDTLS_ECP_C)
157 /* Minimally parse an ECParameters buffer to and mbedtls_asn1_buf
158 *
159 * ECParameters ::= CHOICE {
160 * namedCurve OBJECT IDENTIFIER
161 * specifiedCurve SpecifiedECDomain -- = SEQUENCE { ... }
162 * -- implicitCurve NULL
163 * }
164 */
pk_get_ecparams(unsigned char ** p,const unsigned char * end,mbedtls_asn1_buf * params)165 static int pk_get_ecparams( unsigned char **p, const unsigned char *end,
166 mbedtls_asn1_buf *params )
167 {
168 int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
169
170 if ( end - *p < 1 )
171 return( MBEDTLS_ERROR_ADD( MBEDTLS_ERR_PK_KEY_INVALID_FORMAT,
172 MBEDTLS_ERR_ASN1_OUT_OF_DATA ) );
173
174 /* Tag may be either OID or SEQUENCE */
175 params->tag = **p;
176 if( params->tag != MBEDTLS_ASN1_OID
177 #if defined(MBEDTLS_PK_PARSE_EC_EXTENDED)
178 && params->tag != ( MBEDTLS_ASN1_CONSTRUCTED | MBEDTLS_ASN1_SEQUENCE )
179 #endif
180 )
181 {
182 return( MBEDTLS_ERROR_ADD( MBEDTLS_ERR_PK_KEY_INVALID_FORMAT,
183 MBEDTLS_ERR_ASN1_UNEXPECTED_TAG ) );
184 }
185
186 if( ( ret = mbedtls_asn1_get_tag( p, end, ¶ms->len, params->tag ) ) != 0 )
187 {
188 return( MBEDTLS_ERROR_ADD( MBEDTLS_ERR_PK_KEY_INVALID_FORMAT, ret ) );
189 }
190
191 params->p = *p;
192 *p += params->len;
193
194 if( *p != end )
195 return( MBEDTLS_ERROR_ADD( MBEDTLS_ERR_PK_KEY_INVALID_FORMAT,
196 MBEDTLS_ERR_ASN1_LENGTH_MISMATCH ) );
197
198 return( 0 );
199 }
200
201 #if defined(MBEDTLS_PK_PARSE_EC_EXTENDED)
202 /*
203 * Parse a SpecifiedECDomain (SEC 1 C.2) and (mostly) fill the group with it.
204 * WARNING: the resulting group should only be used with
205 * pk_group_id_from_specified(), since its base point may not be set correctly
206 * if it was encoded compressed.
207 *
208 * SpecifiedECDomain ::= SEQUENCE {
209 * version SpecifiedECDomainVersion(ecdpVer1 | ecdpVer2 | ecdpVer3, ...),
210 * fieldID FieldID {{FieldTypes}},
211 * curve Curve,
212 * base ECPoint,
213 * order INTEGER,
214 * cofactor INTEGER OPTIONAL,
215 * hash HashAlgorithm OPTIONAL,
216 * ...
217 * }
218 *
219 * We only support prime-field as field type, and ignore hash and cofactor.
220 */
pk_group_from_specified(const mbedtls_asn1_buf * params,mbedtls_ecp_group * grp)221 static int pk_group_from_specified( const mbedtls_asn1_buf *params, mbedtls_ecp_group *grp )
222 {
223 int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
224 unsigned char *p = params->p;
225 const unsigned char * const end = params->p + params->len;
226 const unsigned char *end_field, *end_curve;
227 size_t len;
228 int ver;
229
230 /* SpecifiedECDomainVersion ::= INTEGER { 1, 2, 3 } */
231 if( ( ret = mbedtls_asn1_get_int( &p, end, &ver ) ) != 0 )
232 return( MBEDTLS_ERROR_ADD( MBEDTLS_ERR_PK_KEY_INVALID_FORMAT, ret ) );
233
234 if( ver < 1 || ver > 3 )
235 return( MBEDTLS_ERR_PK_KEY_INVALID_FORMAT );
236
237 /*
238 * FieldID { FIELD-ID:IOSet } ::= SEQUENCE { -- Finite field
239 * fieldType FIELD-ID.&id({IOSet}),
240 * parameters FIELD-ID.&Type({IOSet}{@fieldType})
241 * }
242 */
243 if( ( ret = mbedtls_asn1_get_tag( &p, end, &len,
244 MBEDTLS_ASN1_CONSTRUCTED | MBEDTLS_ASN1_SEQUENCE ) ) != 0 )
245 return( ret );
246
247 end_field = p + len;
248
249 /*
250 * FIELD-ID ::= TYPE-IDENTIFIER
251 * FieldTypes FIELD-ID ::= {
252 * { Prime-p IDENTIFIED BY prime-field } |
253 * { Characteristic-two IDENTIFIED BY characteristic-two-field }
254 * }
255 * prime-field OBJECT IDENTIFIER ::= { id-fieldType 1 }
256 */
257 if( ( ret = mbedtls_asn1_get_tag( &p, end_field, &len, MBEDTLS_ASN1_OID ) ) != 0 )
258 return( ret );
259
260 if( len != MBEDTLS_OID_SIZE( MBEDTLS_OID_ANSI_X9_62_PRIME_FIELD ) ||
261 memcmp( p, MBEDTLS_OID_ANSI_X9_62_PRIME_FIELD, len ) != 0 )
262 {
263 return( MBEDTLS_ERR_PK_FEATURE_UNAVAILABLE );
264 }
265
266 p += len;
267
268 /* Prime-p ::= INTEGER -- Field of size p. */
269 if( ( ret = mbedtls_asn1_get_mpi( &p, end_field, &grp->P ) ) != 0 )
270 return( MBEDTLS_ERROR_ADD( MBEDTLS_ERR_PK_KEY_INVALID_FORMAT, ret ) );
271
272 grp->pbits = mbedtls_mpi_bitlen( &grp->P );
273
274 if( p != end_field )
275 return( MBEDTLS_ERROR_ADD( MBEDTLS_ERR_PK_KEY_INVALID_FORMAT,
276 MBEDTLS_ERR_ASN1_LENGTH_MISMATCH ) );
277
278 /*
279 * Curve ::= SEQUENCE {
280 * a FieldElement,
281 * b FieldElement,
282 * seed BIT STRING OPTIONAL
283 * -- Shall be present if used in SpecifiedECDomain
284 * -- with version equal to ecdpVer2 or ecdpVer3
285 * }
286 */
287 if( ( ret = mbedtls_asn1_get_tag( &p, end, &len,
288 MBEDTLS_ASN1_CONSTRUCTED | MBEDTLS_ASN1_SEQUENCE ) ) != 0 )
289 return( ret );
290
291 end_curve = p + len;
292
293 /*
294 * FieldElement ::= OCTET STRING
295 * containing an integer in the case of a prime field
296 */
297 if( ( ret = mbedtls_asn1_get_tag( &p, end_curve, &len, MBEDTLS_ASN1_OCTET_STRING ) ) != 0 ||
298 ( ret = mbedtls_mpi_read_binary( &grp->A, p, len ) ) != 0 )
299 {
300 return( MBEDTLS_ERROR_ADD( MBEDTLS_ERR_PK_KEY_INVALID_FORMAT, ret ) );
301 }
302
303 p += len;
304
305 if( ( ret = mbedtls_asn1_get_tag( &p, end_curve, &len, MBEDTLS_ASN1_OCTET_STRING ) ) != 0 ||
306 ( ret = mbedtls_mpi_read_binary( &grp->B, p, len ) ) != 0 )
307 {
308 return( MBEDTLS_ERROR_ADD( MBEDTLS_ERR_PK_KEY_INVALID_FORMAT, ret ) );
309 }
310
311 p += len;
312
313 /* Ignore seed BIT STRING OPTIONAL */
314 if( ( ret = mbedtls_asn1_get_tag( &p, end_curve, &len, MBEDTLS_ASN1_BIT_STRING ) ) == 0 )
315 p += len;
316
317 if( p != end_curve )
318 return( MBEDTLS_ERROR_ADD( MBEDTLS_ERR_PK_KEY_INVALID_FORMAT,
319 MBEDTLS_ERR_ASN1_LENGTH_MISMATCH ) );
320
321 /*
322 * ECPoint ::= OCTET STRING
323 */
324 if( ( ret = mbedtls_asn1_get_tag( &p, end, &len, MBEDTLS_ASN1_OCTET_STRING ) ) != 0 )
325 return( MBEDTLS_ERROR_ADD( MBEDTLS_ERR_PK_KEY_INVALID_FORMAT, ret ) );
326
327 if( ( ret = mbedtls_ecp_point_read_binary( grp, &grp->G,
328 ( const unsigned char *) p, len ) ) != 0 )
329 {
330 /*
331 * If we can't read the point because it's compressed, cheat by
332 * reading only the X coordinate and the parity bit of Y.
333 */
334 if( ret != MBEDTLS_ERR_ECP_FEATURE_UNAVAILABLE ||
335 ( p[0] != 0x02 && p[0] != 0x03 ) ||
336 len != mbedtls_mpi_size( &grp->P ) + 1 ||
337 mbedtls_mpi_read_binary( &grp->G.X, p + 1, len - 1 ) != 0 ||
338 mbedtls_mpi_lset( &grp->G.Y, p[0] - 2 ) != 0 ||
339 mbedtls_mpi_lset( &grp->G.Z, 1 ) != 0 )
340 {
341 return( MBEDTLS_ERR_PK_KEY_INVALID_FORMAT );
342 }
343 }
344
345 p += len;
346
347 /*
348 * order INTEGER
349 */
350 if( ( ret = mbedtls_asn1_get_mpi( &p, end, &grp->N ) ) != 0 )
351 return( MBEDTLS_ERROR_ADD( MBEDTLS_ERR_PK_KEY_INVALID_FORMAT, ret ) );
352
353 grp->nbits = mbedtls_mpi_bitlen( &grp->N );
354
355 /*
356 * Allow optional elements by purposefully not enforcing p == end here.
357 */
358
359 return( 0 );
360 }
361
362 /*
363 * Find the group id associated with an (almost filled) group as generated by
364 * pk_group_from_specified(), or return an error if unknown.
365 */
pk_group_id_from_group(const mbedtls_ecp_group * grp,mbedtls_ecp_group_id * grp_id)366 static int pk_group_id_from_group( const mbedtls_ecp_group *grp, mbedtls_ecp_group_id *grp_id )
367 {
368 int ret = 0;
369 mbedtls_ecp_group ref;
370 const mbedtls_ecp_group_id *id;
371
372 mbedtls_ecp_group_init( &ref );
373
374 for( id = mbedtls_ecp_grp_id_list(); *id != MBEDTLS_ECP_DP_NONE; id++ )
375 {
376 /* Load the group associated to that id */
377 mbedtls_ecp_group_free( &ref );
378 MBEDTLS_MPI_CHK( mbedtls_ecp_group_load( &ref, *id ) );
379
380 /* Compare to the group we were given, starting with easy tests */
381 if( grp->pbits == ref.pbits && grp->nbits == ref.nbits &&
382 mbedtls_mpi_cmp_mpi( &grp->P, &ref.P ) == 0 &&
383 mbedtls_mpi_cmp_mpi( &grp->A, &ref.A ) == 0 &&
384 mbedtls_mpi_cmp_mpi( &grp->B, &ref.B ) == 0 &&
385 mbedtls_mpi_cmp_mpi( &grp->N, &ref.N ) == 0 &&
386 mbedtls_mpi_cmp_mpi( &grp->G.X, &ref.G.X ) == 0 &&
387 mbedtls_mpi_cmp_mpi( &grp->G.Z, &ref.G.Z ) == 0 &&
388 /* For Y we may only know the parity bit, so compare only that */
389 mbedtls_mpi_get_bit( &grp->G.Y, 0 ) == mbedtls_mpi_get_bit( &ref.G.Y, 0 ) )
390 {
391 break;
392 }
393
394 }
395
396 cleanup:
397 mbedtls_ecp_group_free( &ref );
398
399 *grp_id = *id;
400
401 if( ret == 0 && *id == MBEDTLS_ECP_DP_NONE )
402 ret = MBEDTLS_ERR_ECP_FEATURE_UNAVAILABLE;
403
404 return( ret );
405 }
406
407 /*
408 * Parse a SpecifiedECDomain (SEC 1 C.2) and find the associated group ID
409 */
pk_group_id_from_specified(const mbedtls_asn1_buf * params,mbedtls_ecp_group_id * grp_id)410 static int pk_group_id_from_specified( const mbedtls_asn1_buf *params,
411 mbedtls_ecp_group_id *grp_id )
412 {
413 int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
414 mbedtls_ecp_group grp;
415
416 mbedtls_ecp_group_init( &grp );
417
418 if( ( ret = pk_group_from_specified( params, &grp ) ) != 0 )
419 goto cleanup;
420
421 ret = pk_group_id_from_group( &grp, grp_id );
422
423 cleanup:
424 mbedtls_ecp_group_free( &grp );
425
426 return( ret );
427 }
428 #endif /* MBEDTLS_PK_PARSE_EC_EXTENDED */
429
430 /*
431 * Use EC parameters to initialise an EC group
432 *
433 * ECParameters ::= CHOICE {
434 * namedCurve OBJECT IDENTIFIER
435 * specifiedCurve SpecifiedECDomain -- = SEQUENCE { ... }
436 * -- implicitCurve NULL
437 */
pk_use_ecparams(const mbedtls_asn1_buf * params,mbedtls_ecp_group * grp)438 static int pk_use_ecparams( const mbedtls_asn1_buf *params, mbedtls_ecp_group *grp )
439 {
440 int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
441 mbedtls_ecp_group_id grp_id;
442
443 if( params->tag == MBEDTLS_ASN1_OID )
444 {
445 if( mbedtls_oid_get_ec_grp( params, &grp_id ) != 0 )
446 return( MBEDTLS_ERR_PK_UNKNOWN_NAMED_CURVE );
447 }
448 else
449 {
450 #if defined(MBEDTLS_PK_PARSE_EC_EXTENDED)
451 if( ( ret = pk_group_id_from_specified( params, &grp_id ) ) != 0 )
452 return( ret );
453 #else
454 return( MBEDTLS_ERR_PK_KEY_INVALID_FORMAT );
455 #endif
456 }
457
458 /*
459 * grp may already be initialized; if so, make sure IDs match
460 */
461 if( grp->id != MBEDTLS_ECP_DP_NONE && grp->id != grp_id )
462 return( MBEDTLS_ERR_PK_KEY_INVALID_FORMAT );
463
464 if( ( ret = mbedtls_ecp_group_load( grp, grp_id ) ) != 0 )
465 return( ret );
466
467 return( 0 );
468 }
469
470 /*
471 * EC public key is an EC point
472 *
473 * The caller is responsible for clearing the structure upon failure if
474 * desired. Take care to pass along the possible ECP_FEATURE_UNAVAILABLE
475 * return code of mbedtls_ecp_point_read_binary() and leave p in a usable state.
476 */
pk_get_ecpubkey(unsigned char ** p,const unsigned char * end,mbedtls_ecp_keypair * key)477 static int pk_get_ecpubkey( unsigned char **p, const unsigned char *end,
478 mbedtls_ecp_keypair *key )
479 {
480 int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
481
482 if( ( ret = mbedtls_ecp_point_read_binary( &key->grp, &key->Q,
483 (const unsigned char *) *p, end - *p ) ) == 0 )
484 {
485 ret = mbedtls_ecp_check_pubkey( &key->grp, &key->Q );
486 }
487
488 /*
489 * We know mbedtls_ecp_point_read_binary consumed all bytes or failed
490 */
491 *p = (unsigned char *) end;
492
493 return( ret );
494 }
495 #endif /* MBEDTLS_ECP_C */
496
497 #if defined(MBEDTLS_RSA_C)
498 /*
499 * RSAPublicKey ::= SEQUENCE {
500 * modulus INTEGER, -- n
501 * publicExponent INTEGER -- e
502 * }
503 */
pk_get_rsapubkey(unsigned char ** p,const unsigned char * end,mbedtls_rsa_context * rsa)504 static int pk_get_rsapubkey( unsigned char **p,
505 const unsigned char *end,
506 mbedtls_rsa_context *rsa )
507 {
508 int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
509 size_t len;
510
511 if( ( ret = mbedtls_asn1_get_tag( p, end, &len,
512 MBEDTLS_ASN1_CONSTRUCTED | MBEDTLS_ASN1_SEQUENCE ) ) != 0 )
513 return( MBEDTLS_ERROR_ADD( MBEDTLS_ERR_PK_INVALID_PUBKEY, ret ) );
514
515 if( *p + len != end )
516 return( MBEDTLS_ERROR_ADD( MBEDTLS_ERR_PK_INVALID_PUBKEY,
517 MBEDTLS_ERR_ASN1_LENGTH_MISMATCH ) );
518
519 /* Import N */
520 if( ( ret = mbedtls_asn1_get_tag( p, end, &len, MBEDTLS_ASN1_INTEGER ) ) != 0 )
521 return( MBEDTLS_ERROR_ADD( MBEDTLS_ERR_PK_INVALID_PUBKEY, ret ) );
522
523 if( ( ret = mbedtls_rsa_import_raw( rsa, *p, len, NULL, 0, NULL, 0,
524 NULL, 0, NULL, 0 ) ) != 0 )
525 return( MBEDTLS_ERR_PK_INVALID_PUBKEY );
526
527 *p += len;
528
529 /* Import E */
530 if( ( ret = mbedtls_asn1_get_tag( p, end, &len, MBEDTLS_ASN1_INTEGER ) ) != 0 )
531 return( MBEDTLS_ERROR_ADD( MBEDTLS_ERR_PK_INVALID_PUBKEY, ret ) );
532
533 if( ( ret = mbedtls_rsa_import_raw( rsa, NULL, 0, NULL, 0, NULL, 0,
534 NULL, 0, *p, len ) ) != 0 )
535 return( MBEDTLS_ERR_PK_INVALID_PUBKEY );
536
537 *p += len;
538
539 if( mbedtls_rsa_complete( rsa ) != 0 ||
540 mbedtls_rsa_check_pubkey( rsa ) != 0 )
541 {
542 return( MBEDTLS_ERR_PK_INVALID_PUBKEY );
543 }
544
545 if( *p != end )
546 return( MBEDTLS_ERROR_ADD( MBEDTLS_ERR_PK_INVALID_PUBKEY,
547 MBEDTLS_ERR_ASN1_LENGTH_MISMATCH ) );
548
549 return( 0 );
550 }
551 #endif /* MBEDTLS_RSA_C */
552
553 /* Get a PK algorithm identifier
554 *
555 * AlgorithmIdentifier ::= SEQUENCE {
556 * algorithm OBJECT IDENTIFIER,
557 * parameters ANY DEFINED BY algorithm OPTIONAL }
558 */
pk_get_pk_alg(unsigned char ** p,const unsigned char * end,mbedtls_pk_type_t * pk_alg,mbedtls_asn1_buf * params)559 static int pk_get_pk_alg( unsigned char **p,
560 const unsigned char *end,
561 mbedtls_pk_type_t *pk_alg, mbedtls_asn1_buf *params )
562 {
563 int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
564 mbedtls_asn1_buf alg_oid;
565
566 memset( params, 0, sizeof(mbedtls_asn1_buf) );
567
568 if( ( ret = mbedtls_asn1_get_alg( p, end, &alg_oid, params ) ) != 0 )
569 return( MBEDTLS_ERROR_ADD( MBEDTLS_ERR_PK_INVALID_ALG, ret ) );
570
571 if( mbedtls_oid_get_pk_alg( &alg_oid, pk_alg ) != 0 )
572 return( MBEDTLS_ERR_PK_UNKNOWN_PK_ALG );
573
574 /*
575 * No parameters with RSA (only for EC)
576 */
577 if( *pk_alg == MBEDTLS_PK_RSA &&
578 ( ( params->tag != MBEDTLS_ASN1_NULL && params->tag != 0 ) ||
579 params->len != 0 ) )
580 {
581 return( MBEDTLS_ERR_PK_INVALID_ALG );
582 }
583
584 return( 0 );
585 }
586
587 /*
588 * SubjectPublicKeyInfo ::= SEQUENCE {
589 * algorithm AlgorithmIdentifier,
590 * subjectPublicKey BIT STRING }
591 */
mbedtls_pk_parse_subpubkey(unsigned char ** p,const unsigned char * end,mbedtls_pk_context * pk)592 int mbedtls_pk_parse_subpubkey( unsigned char **p, const unsigned char *end,
593 mbedtls_pk_context *pk )
594 {
595 int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
596 size_t len;
597 mbedtls_asn1_buf alg_params;
598 mbedtls_pk_type_t pk_alg = MBEDTLS_PK_NONE;
599 const mbedtls_pk_info_t *pk_info;
600
601 if( ( ret = mbedtls_asn1_get_tag( p, end, &len,
602 MBEDTLS_ASN1_CONSTRUCTED | MBEDTLS_ASN1_SEQUENCE ) ) != 0 )
603 {
604 return( MBEDTLS_ERROR_ADD( MBEDTLS_ERR_PK_KEY_INVALID_FORMAT, ret ) );
605 }
606
607 end = *p + len;
608
609 if( ( ret = pk_get_pk_alg( p, end, &pk_alg, &alg_params ) ) != 0 )
610 return( ret );
611
612 if( ( ret = mbedtls_asn1_get_bitstring_null( p, end, &len ) ) != 0 )
613 return( MBEDTLS_ERROR_ADD( MBEDTLS_ERR_PK_INVALID_PUBKEY, ret ) );
614
615 if( *p + len != end )
616 return( MBEDTLS_ERROR_ADD( MBEDTLS_ERR_PK_INVALID_PUBKEY,
617 MBEDTLS_ERR_ASN1_LENGTH_MISMATCH ) );
618
619 if( ( pk_info = mbedtls_pk_info_from_type( pk_alg ) ) == NULL )
620 return( MBEDTLS_ERR_PK_UNKNOWN_PK_ALG );
621
622 if( ( ret = mbedtls_pk_setup( pk, pk_info ) ) != 0 )
623 return( ret );
624
625 #if defined(MBEDTLS_RSA_C)
626 if( pk_alg == MBEDTLS_PK_RSA )
627 {
628 ret = pk_get_rsapubkey( p, end, mbedtls_pk_rsa( *pk ) );
629 } else
630 #endif /* MBEDTLS_RSA_C */
631 #if defined(MBEDTLS_ECP_C)
632 if( pk_alg == MBEDTLS_PK_ECKEY_DH || pk_alg == MBEDTLS_PK_ECKEY )
633 {
634 ret = pk_use_ecparams( &alg_params, &mbedtls_pk_ec( *pk )->grp );
635 if( ret == 0 )
636 ret = pk_get_ecpubkey( p, end, mbedtls_pk_ec( *pk ) );
637 } else
638 #endif /* MBEDTLS_ECP_C */
639 ret = MBEDTLS_ERR_PK_UNKNOWN_PK_ALG;
640
641 if( ret == 0 && *p != end )
642 ret = MBEDTLS_ERROR_ADD( MBEDTLS_ERR_PK_INVALID_PUBKEY,
643 MBEDTLS_ERR_ASN1_LENGTH_MISMATCH );
644
645 if( ret != 0 )
646 mbedtls_pk_free( pk );
647
648 return( ret );
649 }
650
651 #if defined(MBEDTLS_RSA_C)
652 /*
653 * Wrapper around mbedtls_asn1_get_mpi() that rejects zero.
654 *
655 * The value zero is:
656 * - never a valid value for an RSA parameter
657 * - interpreted as "omitted, please reconstruct" by mbedtls_rsa_complete().
658 *
659 * Since values can't be omitted in PKCS#1, passing a zero value to
660 * rsa_complete() would be incorrect, so reject zero values early.
661 */
asn1_get_nonzero_mpi(unsigned char ** p,const unsigned char * end,mbedtls_mpi * X)662 static int asn1_get_nonzero_mpi( unsigned char **p,
663 const unsigned char *end,
664 mbedtls_mpi *X )
665 {
666 int ret;
667
668 ret = mbedtls_asn1_get_mpi( p, end, X );
669 if( ret != 0 )
670 return( ret );
671
672 if( mbedtls_mpi_cmp_int( X, 0 ) == 0 )
673 return( MBEDTLS_ERR_PK_KEY_INVALID_FORMAT );
674
675 return( 0 );
676 }
677
678 /*
679 * Parse a PKCS#1 encoded private RSA key
680 */
pk_parse_key_pkcs1_der(mbedtls_rsa_context * rsa,const unsigned char * key,size_t keylen)681 static int pk_parse_key_pkcs1_der( mbedtls_rsa_context *rsa,
682 const unsigned char *key,
683 size_t keylen )
684 {
685 int ret, version;
686 size_t len;
687 unsigned char *p, *end;
688
689 mbedtls_mpi T;
690 mbedtls_mpi_init( &T );
691
692 p = (unsigned char *) key;
693 end = p + keylen;
694
695 /*
696 * This function parses the RSAPrivateKey (PKCS#1)
697 *
698 * RSAPrivateKey ::= SEQUENCE {
699 * version Version,
700 * modulus INTEGER, -- n
701 * publicExponent INTEGER, -- e
702 * privateExponent INTEGER, -- d
703 * prime1 INTEGER, -- p
704 * prime2 INTEGER, -- q
705 * exponent1 INTEGER, -- d mod (p-1)
706 * exponent2 INTEGER, -- d mod (q-1)
707 * coefficient INTEGER, -- (inverse of q) mod p
708 * otherPrimeInfos OtherPrimeInfos OPTIONAL
709 * }
710 */
711 if( ( ret = mbedtls_asn1_get_tag( &p, end, &len,
712 MBEDTLS_ASN1_CONSTRUCTED | MBEDTLS_ASN1_SEQUENCE ) ) != 0 )
713 {
714 return( MBEDTLS_ERROR_ADD( MBEDTLS_ERR_PK_KEY_INVALID_FORMAT, ret ) );
715 }
716
717 end = p + len;
718
719 if( ( ret = mbedtls_asn1_get_int( &p, end, &version ) ) != 0 )
720 {
721 return( MBEDTLS_ERROR_ADD( MBEDTLS_ERR_PK_KEY_INVALID_FORMAT, ret ) );
722 }
723
724 if( version != 0 )
725 {
726 return( MBEDTLS_ERR_PK_KEY_INVALID_VERSION );
727 }
728
729 /* Import N */
730 if( ( ret = asn1_get_nonzero_mpi( &p, end, &T ) ) != 0 ||
731 ( ret = mbedtls_rsa_import( rsa, &T, NULL, NULL,
732 NULL, NULL ) ) != 0 )
733 goto cleanup;
734
735 /* Import E */
736 if( ( ret = asn1_get_nonzero_mpi( &p, end, &T ) ) != 0 ||
737 ( ret = mbedtls_rsa_import( rsa, NULL, NULL, NULL,
738 NULL, &T ) ) != 0 )
739 goto cleanup;
740
741 /* Import D */
742 if( ( ret = asn1_get_nonzero_mpi( &p, end, &T ) ) != 0 ||
743 ( ret = mbedtls_rsa_import( rsa, NULL, NULL, NULL,
744 &T, NULL ) ) != 0 )
745 goto cleanup;
746
747 /* Import P */
748 if( ( ret = asn1_get_nonzero_mpi( &p, end, &T ) ) != 0 ||
749 ( ret = mbedtls_rsa_import( rsa, NULL, &T, NULL,
750 NULL, NULL ) ) != 0 )
751 goto cleanup;
752
753 /* Import Q */
754 if( ( ret = asn1_get_nonzero_mpi( &p, end, &T ) ) != 0 ||
755 ( ret = mbedtls_rsa_import( rsa, NULL, NULL, &T,
756 NULL, NULL ) ) != 0 )
757 goto cleanup;
758
759 #if !defined(MBEDTLS_RSA_NO_CRT) && !defined(MBEDTLS_RSA_ALT)
760 /*
761 * The RSA CRT parameters DP, DQ and QP are nominally redundant, in
762 * that they can be easily recomputed from D, P and Q. However by
763 * parsing them from the PKCS1 structure it is possible to avoid
764 * recalculating them which both reduces the overhead of loading
765 * RSA private keys into memory and also avoids side channels which
766 * can arise when computing those values, since all of D, P, and Q
767 * are secret. See https://eprint.iacr.org/2020/055 for a
768 * description of one such attack.
769 */
770
771 /* Import DP */
772 if( ( ret = asn1_get_nonzero_mpi( &p, end, &T ) ) != 0 ||
773 ( ret = mbedtls_mpi_copy( &rsa->DP, &T ) ) != 0 )
774 goto cleanup;
775
776 /* Import DQ */
777 if( ( ret = asn1_get_nonzero_mpi( &p, end, &T ) ) != 0 ||
778 ( ret = mbedtls_mpi_copy( &rsa->DQ, &T ) ) != 0 )
779 goto cleanup;
780
781 /* Import QP */
782 if( ( ret = asn1_get_nonzero_mpi( &p, end, &T ) ) != 0 ||
783 ( ret = mbedtls_mpi_copy( &rsa->QP, &T ) ) != 0 )
784 goto cleanup;
785
786 #else
787 /* Verify existence of the CRT params */
788 if( ( ret = asn1_get_nonzero_mpi( &p, end, &T ) ) != 0 ||
789 ( ret = asn1_get_nonzero_mpi( &p, end, &T ) ) != 0 ||
790 ( ret = asn1_get_nonzero_mpi( &p, end, &T ) ) != 0 )
791 goto cleanup;
792 #endif
793
794 /* rsa_complete() doesn't complete anything with the default
795 * implementation but is still called:
796 * - for the benefit of alternative implementation that may want to
797 * pre-compute stuff beyond what's provided (eg Montgomery factors)
798 * - as is also sanity-checks the key
799 *
800 * Furthermore, we also check the public part for consistency with
801 * mbedtls_pk_parse_pubkey(), as it includes size minima for example.
802 */
803 if( ( ret = mbedtls_rsa_complete( rsa ) ) != 0 ||
804 ( ret = mbedtls_rsa_check_pubkey( rsa ) ) != 0 )
805 {
806 goto cleanup;
807 }
808
809 if( p != end )
810 {
811 ret = MBEDTLS_ERROR_ADD( MBEDTLS_ERR_PK_KEY_INVALID_FORMAT,
812 MBEDTLS_ERR_ASN1_LENGTH_MISMATCH );
813 }
814
815 cleanup:
816
817 mbedtls_mpi_free( &T );
818
819 if( ret != 0 )
820 {
821 /* Wrap error code if it's coming from a lower level */
822 if( ( ret & 0xff80 ) == 0 )
823 ret = MBEDTLS_ERROR_ADD( MBEDTLS_ERR_PK_KEY_INVALID_FORMAT, ret );
824 else
825 ret = MBEDTLS_ERR_PK_KEY_INVALID_FORMAT;
826
827 mbedtls_rsa_free( rsa );
828 }
829
830 return( ret );
831 }
832 #endif /* MBEDTLS_RSA_C */
833
834 #if defined(MBEDTLS_ECP_C)
835 /*
836 * Parse a SEC1 encoded private EC key
837 */
pk_parse_key_sec1_der(mbedtls_ecp_keypair * eck,const unsigned char * key,size_t keylen,int (* f_rng)(void *,unsigned char *,size_t),void * p_rng)838 static int pk_parse_key_sec1_der( mbedtls_ecp_keypair *eck,
839 const unsigned char *key, size_t keylen,
840 int (*f_rng)(void *, unsigned char *, size_t), void *p_rng )
841 {
842 int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
843 int version, pubkey_done;
844 size_t len;
845 mbedtls_asn1_buf params = { 0, 0, NULL };
846 unsigned char *p = (unsigned char *) key;
847 unsigned char *end = p + keylen;
848 unsigned char *end2;
849
850 /*
851 * RFC 5915, or SEC1 Appendix C.4
852 *
853 * ECPrivateKey ::= SEQUENCE {
854 * version INTEGER { ecPrivkeyVer1(1) } (ecPrivkeyVer1),
855 * privateKey OCTET STRING,
856 * parameters [0] ECParameters {{ NamedCurve }} OPTIONAL,
857 * publicKey [1] BIT STRING OPTIONAL
858 * }
859 */
860 if( ( ret = mbedtls_asn1_get_tag( &p, end, &len,
861 MBEDTLS_ASN1_CONSTRUCTED | MBEDTLS_ASN1_SEQUENCE ) ) != 0 )
862 {
863 return( MBEDTLS_ERROR_ADD( MBEDTLS_ERR_PK_KEY_INVALID_FORMAT, ret ) );
864 }
865
866 end = p + len;
867
868 if( ( ret = mbedtls_asn1_get_int( &p, end, &version ) ) != 0 )
869 return( MBEDTLS_ERROR_ADD( MBEDTLS_ERR_PK_KEY_INVALID_FORMAT, ret ) );
870
871 if( version != 1 )
872 return( MBEDTLS_ERR_PK_KEY_INVALID_VERSION );
873
874 if( ( ret = mbedtls_asn1_get_tag( &p, end, &len, MBEDTLS_ASN1_OCTET_STRING ) ) != 0 )
875 return( MBEDTLS_ERROR_ADD( MBEDTLS_ERR_PK_KEY_INVALID_FORMAT, ret ) );
876
877 if( ( ret = mbedtls_mpi_read_binary( &eck->d, p, len ) ) != 0 )
878 {
879 mbedtls_ecp_keypair_free( eck );
880 return( MBEDTLS_ERROR_ADD( MBEDTLS_ERR_PK_KEY_INVALID_FORMAT, ret ) );
881 }
882
883 p += len;
884
885 pubkey_done = 0;
886 if( p != end )
887 {
888 /*
889 * Is 'parameters' present?
890 */
891 if( ( ret = mbedtls_asn1_get_tag( &p, end, &len,
892 MBEDTLS_ASN1_CONTEXT_SPECIFIC | MBEDTLS_ASN1_CONSTRUCTED | 0 ) ) == 0 )
893 {
894 if( ( ret = pk_get_ecparams( &p, p + len, ¶ms) ) != 0 ||
895 ( ret = pk_use_ecparams( ¶ms, &eck->grp ) ) != 0 )
896 {
897 mbedtls_ecp_keypair_free( eck );
898 return( ret );
899 }
900 }
901 else if( ret != MBEDTLS_ERR_ASN1_UNEXPECTED_TAG )
902 {
903 mbedtls_ecp_keypair_free( eck );
904 return( MBEDTLS_ERROR_ADD( MBEDTLS_ERR_PK_KEY_INVALID_FORMAT, ret ) );
905 }
906 }
907
908 if( p != end )
909 {
910 /*
911 * Is 'publickey' present? If not, or if we can't read it (eg because it
912 * is compressed), create it from the private key.
913 */
914 if( ( ret = mbedtls_asn1_get_tag( &p, end, &len,
915 MBEDTLS_ASN1_CONTEXT_SPECIFIC | MBEDTLS_ASN1_CONSTRUCTED | 1 ) ) == 0 )
916 {
917 end2 = p + len;
918
919 if( ( ret = mbedtls_asn1_get_bitstring_null( &p, end2, &len ) ) != 0 )
920 return( MBEDTLS_ERROR_ADD( MBEDTLS_ERR_PK_KEY_INVALID_FORMAT, ret ) );
921
922 if( p + len != end2 )
923 return( MBEDTLS_ERROR_ADD( MBEDTLS_ERR_PK_KEY_INVALID_FORMAT,
924 MBEDTLS_ERR_ASN1_LENGTH_MISMATCH ) );
925
926 if( ( ret = pk_get_ecpubkey( &p, end2, eck ) ) == 0 )
927 pubkey_done = 1;
928 else
929 {
930 /*
931 * The only acceptable failure mode of pk_get_ecpubkey() above
932 * is if the point format is not recognized.
933 */
934 if( ret != MBEDTLS_ERR_ECP_FEATURE_UNAVAILABLE )
935 return( MBEDTLS_ERR_PK_KEY_INVALID_FORMAT );
936 }
937 }
938 else if( ret != MBEDTLS_ERR_ASN1_UNEXPECTED_TAG )
939 {
940 mbedtls_ecp_keypair_free( eck );
941 return( MBEDTLS_ERROR_ADD( MBEDTLS_ERR_PK_KEY_INVALID_FORMAT, ret ) );
942 }
943 }
944
945 if( ! pubkey_done &&
946 ( ret = mbedtls_ecp_mul( &eck->grp, &eck->Q, &eck->d, &eck->grp.G,
947 f_rng, p_rng ) ) != 0 )
948 {
949 mbedtls_ecp_keypair_free( eck );
950 return( MBEDTLS_ERROR_ADD( MBEDTLS_ERR_PK_KEY_INVALID_FORMAT, ret ) );
951 }
952
953 if( ( ret = mbedtls_ecp_check_privkey( &eck->grp, &eck->d ) ) != 0 )
954 {
955 mbedtls_ecp_keypair_free( eck );
956 return( ret );
957 }
958
959 return( 0 );
960 }
961 #endif /* MBEDTLS_ECP_C */
962
963 /*
964 * Parse an unencrypted PKCS#8 encoded private key
965 *
966 * Notes:
967 *
968 * - This function does not own the key buffer. It is the
969 * responsibility of the caller to take care of zeroizing
970 * and freeing it after use.
971 *
972 * - The function is responsible for freeing the provided
973 * PK context on failure.
974 *
975 */
pk_parse_key_pkcs8_unencrypted_der(mbedtls_pk_context * pk,const unsigned char * key,size_t keylen,int (* f_rng)(void *,unsigned char *,size_t),void * p_rng)976 static int pk_parse_key_pkcs8_unencrypted_der(
977 mbedtls_pk_context *pk,
978 const unsigned char* key, size_t keylen,
979 int (*f_rng)(void *, unsigned char *, size_t), void *p_rng )
980 {
981 int ret, version;
982 size_t len;
983 mbedtls_asn1_buf params;
984 unsigned char *p = (unsigned char *) key;
985 unsigned char *end = p + keylen;
986 mbedtls_pk_type_t pk_alg = MBEDTLS_PK_NONE;
987 const mbedtls_pk_info_t *pk_info;
988
989 #if !defined(MBEDTLS_ECP_C)
990 (void) f_rng;
991 (void) p_rng;
992 #endif
993
994 /*
995 * This function parses the PrivateKeyInfo object (PKCS#8 v1.2 = RFC 5208)
996 *
997 * PrivateKeyInfo ::= SEQUENCE {
998 * version Version,
999 * privateKeyAlgorithm PrivateKeyAlgorithmIdentifier,
1000 * privateKey PrivateKey,
1001 * attributes [0] IMPLICIT Attributes OPTIONAL }
1002 *
1003 * Version ::= INTEGER
1004 * PrivateKeyAlgorithmIdentifier ::= AlgorithmIdentifier
1005 * PrivateKey ::= OCTET STRING
1006 *
1007 * The PrivateKey OCTET STRING is a SEC1 ECPrivateKey
1008 */
1009
1010 if( ( ret = mbedtls_asn1_get_tag( &p, end, &len,
1011 MBEDTLS_ASN1_CONSTRUCTED | MBEDTLS_ASN1_SEQUENCE ) ) != 0 )
1012 {
1013 return( MBEDTLS_ERROR_ADD( MBEDTLS_ERR_PK_KEY_INVALID_FORMAT, ret ) );
1014 }
1015
1016 end = p + len;
1017
1018 if( ( ret = mbedtls_asn1_get_int( &p, end, &version ) ) != 0 )
1019 return( MBEDTLS_ERROR_ADD( MBEDTLS_ERR_PK_KEY_INVALID_FORMAT, ret ) );
1020
1021 if( version != 0 )
1022 return( MBEDTLS_ERROR_ADD( MBEDTLS_ERR_PK_KEY_INVALID_VERSION, ret ) );
1023
1024 if( ( ret = pk_get_pk_alg( &p, end, &pk_alg, ¶ms ) ) != 0 )
1025 {
1026 return( ret );
1027 }
1028
1029 if( ( ret = mbedtls_asn1_get_tag( &p, end, &len, MBEDTLS_ASN1_OCTET_STRING ) ) != 0 )
1030 return( MBEDTLS_ERROR_ADD( MBEDTLS_ERR_PK_KEY_INVALID_FORMAT, ret ) );
1031
1032 if( len < 1 )
1033 return( MBEDTLS_ERROR_ADD( MBEDTLS_ERR_PK_KEY_INVALID_FORMAT,
1034 MBEDTLS_ERR_ASN1_OUT_OF_DATA ) );
1035
1036 if( ( pk_info = mbedtls_pk_info_from_type( pk_alg ) ) == NULL )
1037 return( MBEDTLS_ERR_PK_UNKNOWN_PK_ALG );
1038
1039 if( ( ret = mbedtls_pk_setup( pk, pk_info ) ) != 0 )
1040 return( ret );
1041
1042 #if defined(MBEDTLS_RSA_C)
1043 if( pk_alg == MBEDTLS_PK_RSA )
1044 {
1045 if( ( ret = pk_parse_key_pkcs1_der( mbedtls_pk_rsa( *pk ), p, len ) ) != 0 )
1046 {
1047 mbedtls_pk_free( pk );
1048 return( ret );
1049 }
1050 } else
1051 #endif /* MBEDTLS_RSA_C */
1052 #if defined(MBEDTLS_ECP_C)
1053 if( pk_alg == MBEDTLS_PK_ECKEY || pk_alg == MBEDTLS_PK_ECKEY_DH )
1054 {
1055 if( ( ret = pk_use_ecparams( ¶ms, &mbedtls_pk_ec( *pk )->grp ) ) != 0 ||
1056 ( ret = pk_parse_key_sec1_der( mbedtls_pk_ec( *pk ), p, len, f_rng, p_rng ) ) != 0 )
1057 {
1058 mbedtls_pk_free( pk );
1059 return( ret );
1060 }
1061 } else
1062 #endif /* MBEDTLS_ECP_C */
1063 return( MBEDTLS_ERR_PK_UNKNOWN_PK_ALG );
1064
1065 return( 0 );
1066 }
1067
1068 /*
1069 * Parse an encrypted PKCS#8 encoded private key
1070 *
1071 * To save space, the decryption happens in-place on the given key buffer.
1072 * Also, while this function may modify the keybuffer, it doesn't own it,
1073 * and instead it is the responsibility of the caller to zeroize and properly
1074 * free it after use.
1075 *
1076 */
1077 #if defined(MBEDTLS_PKCS12_C) || defined(MBEDTLS_PKCS5_C)
pk_parse_key_pkcs8_encrypted_der(mbedtls_pk_context * pk,unsigned char * key,size_t keylen,const unsigned char * pwd,size_t pwdlen,int (* f_rng)(void *,unsigned char *,size_t),void * p_rng)1078 static int pk_parse_key_pkcs8_encrypted_der(
1079 mbedtls_pk_context *pk,
1080 unsigned char *key, size_t keylen,
1081 const unsigned char *pwd, size_t pwdlen,
1082 int (*f_rng)(void *, unsigned char *, size_t), void *p_rng )
1083 {
1084 int ret, decrypted = 0;
1085 size_t len;
1086 unsigned char *buf;
1087 unsigned char *p, *end;
1088 mbedtls_asn1_buf pbe_alg_oid, pbe_params;
1089 #if defined(MBEDTLS_PKCS12_C)
1090 mbedtls_cipher_type_t cipher_alg;
1091 mbedtls_md_type_t md_alg;
1092 #endif
1093
1094 p = key;
1095 end = p + keylen;
1096
1097 if( pwdlen == 0 )
1098 return( MBEDTLS_ERR_PK_PASSWORD_REQUIRED );
1099
1100 /*
1101 * This function parses the EncryptedPrivateKeyInfo object (PKCS#8)
1102 *
1103 * EncryptedPrivateKeyInfo ::= SEQUENCE {
1104 * encryptionAlgorithm EncryptionAlgorithmIdentifier,
1105 * encryptedData EncryptedData
1106 * }
1107 *
1108 * EncryptionAlgorithmIdentifier ::= AlgorithmIdentifier
1109 *
1110 * EncryptedData ::= OCTET STRING
1111 *
1112 * The EncryptedData OCTET STRING is a PKCS#8 PrivateKeyInfo
1113 *
1114 */
1115 if( ( ret = mbedtls_asn1_get_tag( &p, end, &len,
1116 MBEDTLS_ASN1_CONSTRUCTED | MBEDTLS_ASN1_SEQUENCE ) ) != 0 )
1117 {
1118 return( MBEDTLS_ERROR_ADD( MBEDTLS_ERR_PK_KEY_INVALID_FORMAT, ret ) );
1119 }
1120
1121 end = p + len;
1122
1123 if( ( ret = mbedtls_asn1_get_alg( &p, end, &pbe_alg_oid, &pbe_params ) ) != 0 )
1124 return( MBEDTLS_ERROR_ADD( MBEDTLS_ERR_PK_KEY_INVALID_FORMAT, ret ) );
1125
1126 if( ( ret = mbedtls_asn1_get_tag( &p, end, &len, MBEDTLS_ASN1_OCTET_STRING ) ) != 0 )
1127 return( MBEDTLS_ERROR_ADD( MBEDTLS_ERR_PK_KEY_INVALID_FORMAT, ret ) );
1128
1129 buf = p;
1130
1131 /*
1132 * Decrypt EncryptedData with appropriate PBE
1133 */
1134 #if defined(MBEDTLS_PKCS12_C)
1135 if( mbedtls_oid_get_pkcs12_pbe_alg( &pbe_alg_oid, &md_alg, &cipher_alg ) == 0 )
1136 {
1137 if( ( ret = mbedtls_pkcs12_pbe( &pbe_params, MBEDTLS_PKCS12_PBE_DECRYPT,
1138 cipher_alg, md_alg,
1139 pwd, pwdlen, p, len, buf ) ) != 0 )
1140 {
1141 if( ret == MBEDTLS_ERR_PKCS12_PASSWORD_MISMATCH )
1142 return( MBEDTLS_ERR_PK_PASSWORD_MISMATCH );
1143
1144 return( ret );
1145 }
1146
1147 decrypted = 1;
1148 }
1149 else
1150 #endif /* MBEDTLS_PKCS12_C */
1151 #if defined(MBEDTLS_PKCS5_C)
1152 if( MBEDTLS_OID_CMP( MBEDTLS_OID_PKCS5_PBES2, &pbe_alg_oid ) == 0 )
1153 {
1154 if( ( ret = mbedtls_pkcs5_pbes2( &pbe_params, MBEDTLS_PKCS5_DECRYPT, pwd, pwdlen,
1155 p, len, buf ) ) != 0 )
1156 {
1157 if( ret == MBEDTLS_ERR_PKCS5_PASSWORD_MISMATCH )
1158 return( MBEDTLS_ERR_PK_PASSWORD_MISMATCH );
1159
1160 return( ret );
1161 }
1162
1163 decrypted = 1;
1164 }
1165 else
1166 #endif /* MBEDTLS_PKCS5_C */
1167 {
1168 ((void) pwd);
1169 }
1170
1171 if( decrypted == 0 )
1172 return( MBEDTLS_ERR_PK_FEATURE_UNAVAILABLE );
1173
1174 return( pk_parse_key_pkcs8_unencrypted_der( pk, buf, len, f_rng, p_rng ) );
1175 }
1176 #endif /* MBEDTLS_PKCS12_C || MBEDTLS_PKCS5_C */
1177
1178 /*
1179 * Parse a private key
1180 */
mbedtls_pk_parse_key(mbedtls_pk_context * pk,const unsigned char * key,size_t keylen,const unsigned char * pwd,size_t pwdlen,int (* f_rng)(void *,unsigned char *,size_t),void * p_rng)1181 int mbedtls_pk_parse_key( mbedtls_pk_context *pk,
1182 const unsigned char *key, size_t keylen,
1183 const unsigned char *pwd, size_t pwdlen,
1184 int (*f_rng)(void *, unsigned char *, size_t), void *p_rng )
1185 {
1186 int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
1187 const mbedtls_pk_info_t *pk_info;
1188 #if defined(MBEDTLS_PEM_PARSE_C)
1189 size_t len;
1190 mbedtls_pem_context pem;
1191 #endif
1192
1193 if( keylen == 0 )
1194 return( MBEDTLS_ERR_PK_KEY_INVALID_FORMAT );
1195
1196 #if defined(MBEDTLS_PEM_PARSE_C)
1197 mbedtls_pem_init( &pem );
1198
1199 #if defined(MBEDTLS_RSA_C)
1200 /* Avoid calling mbedtls_pem_read_buffer() on non-null-terminated string */
1201 if( key[keylen - 1] != '\0' )
1202 ret = MBEDTLS_ERR_PEM_NO_HEADER_FOOTER_PRESENT;
1203 else
1204 ret = mbedtls_pem_read_buffer( &pem,
1205 "-----BEGIN RSA PRIVATE KEY-----",
1206 "-----END RSA PRIVATE KEY-----",
1207 key, pwd, pwdlen, &len );
1208
1209 if( ret == 0 )
1210 {
1211 pk_info = mbedtls_pk_info_from_type( MBEDTLS_PK_RSA );
1212 if( ( ret = mbedtls_pk_setup( pk, pk_info ) ) != 0 ||
1213 ( ret = pk_parse_key_pkcs1_der( mbedtls_pk_rsa( *pk ),
1214 pem.buf, pem.buflen ) ) != 0 )
1215 {
1216 mbedtls_pk_free( pk );
1217 }
1218
1219 mbedtls_pem_free( &pem );
1220 return( ret );
1221 }
1222 else if( ret == MBEDTLS_ERR_PEM_PASSWORD_MISMATCH )
1223 return( MBEDTLS_ERR_PK_PASSWORD_MISMATCH );
1224 else if( ret == MBEDTLS_ERR_PEM_PASSWORD_REQUIRED )
1225 return( MBEDTLS_ERR_PK_PASSWORD_REQUIRED );
1226 else if( ret != MBEDTLS_ERR_PEM_NO_HEADER_FOOTER_PRESENT )
1227 return( ret );
1228 #endif /* MBEDTLS_RSA_C */
1229
1230 #if defined(MBEDTLS_ECP_C)
1231 /* Avoid calling mbedtls_pem_read_buffer() on non-null-terminated string */
1232 if( key[keylen - 1] != '\0' )
1233 ret = MBEDTLS_ERR_PEM_NO_HEADER_FOOTER_PRESENT;
1234 else
1235 ret = mbedtls_pem_read_buffer( &pem,
1236 "-----BEGIN EC PRIVATE KEY-----",
1237 "-----END EC PRIVATE KEY-----",
1238 key, pwd, pwdlen, &len );
1239 if( ret == 0 )
1240 {
1241 pk_info = mbedtls_pk_info_from_type( MBEDTLS_PK_ECKEY );
1242
1243 if( ( ret = mbedtls_pk_setup( pk, pk_info ) ) != 0 ||
1244 ( ret = pk_parse_key_sec1_der( mbedtls_pk_ec( *pk ),
1245 pem.buf, pem.buflen,
1246 f_rng, p_rng ) ) != 0 )
1247 {
1248 mbedtls_pk_free( pk );
1249 }
1250
1251 mbedtls_pem_free( &pem );
1252 return( ret );
1253 }
1254 else if( ret == MBEDTLS_ERR_PEM_PASSWORD_MISMATCH )
1255 return( MBEDTLS_ERR_PK_PASSWORD_MISMATCH );
1256 else if( ret == MBEDTLS_ERR_PEM_PASSWORD_REQUIRED )
1257 return( MBEDTLS_ERR_PK_PASSWORD_REQUIRED );
1258 else if( ret != MBEDTLS_ERR_PEM_NO_HEADER_FOOTER_PRESENT )
1259 return( ret );
1260 #endif /* MBEDTLS_ECP_C */
1261
1262 /* Avoid calling mbedtls_pem_read_buffer() on non-null-terminated string */
1263 if( key[keylen - 1] != '\0' )
1264 ret = MBEDTLS_ERR_PEM_NO_HEADER_FOOTER_PRESENT;
1265 else
1266 ret = mbedtls_pem_read_buffer( &pem,
1267 "-----BEGIN PRIVATE KEY-----",
1268 "-----END PRIVATE KEY-----",
1269 key, NULL, 0, &len );
1270 if( ret == 0 )
1271 {
1272 if( ( ret = pk_parse_key_pkcs8_unencrypted_der( pk,
1273 pem.buf, pem.buflen, f_rng, p_rng ) ) != 0 )
1274 {
1275 mbedtls_pk_free( pk );
1276 }
1277
1278 mbedtls_pem_free( &pem );
1279 return( ret );
1280 }
1281 else if( ret != MBEDTLS_ERR_PEM_NO_HEADER_FOOTER_PRESENT )
1282 return( ret );
1283
1284 #if defined(MBEDTLS_PKCS12_C) || defined(MBEDTLS_PKCS5_C)
1285 /* Avoid calling mbedtls_pem_read_buffer() on non-null-terminated string */
1286 if( key[keylen - 1] != '\0' )
1287 ret = MBEDTLS_ERR_PEM_NO_HEADER_FOOTER_PRESENT;
1288 else
1289 ret = mbedtls_pem_read_buffer( &pem,
1290 "-----BEGIN ENCRYPTED PRIVATE KEY-----",
1291 "-----END ENCRYPTED PRIVATE KEY-----",
1292 key, NULL, 0, &len );
1293 if( ret == 0 )
1294 {
1295 if( ( ret = pk_parse_key_pkcs8_encrypted_der( pk, pem.buf, pem.buflen,
1296 pwd, pwdlen, f_rng, p_rng ) ) != 0 )
1297 {
1298 mbedtls_pk_free( pk );
1299 }
1300
1301 mbedtls_pem_free( &pem );
1302 return( ret );
1303 }
1304 else if( ret != MBEDTLS_ERR_PEM_NO_HEADER_FOOTER_PRESENT )
1305 return( ret );
1306 #endif /* MBEDTLS_PKCS12_C || MBEDTLS_PKCS5_C */
1307 #else
1308 ((void) pwd);
1309 ((void) pwdlen);
1310 #endif /* MBEDTLS_PEM_PARSE_C */
1311
1312 /*
1313 * At this point we only know it's not a PEM formatted key. Could be any
1314 * of the known DER encoded private key formats
1315 *
1316 * We try the different DER format parsers to see if one passes without
1317 * error
1318 */
1319 #if defined(MBEDTLS_PKCS12_C) || defined(MBEDTLS_PKCS5_C)
1320 if( pwdlen != 0 )
1321 {
1322 unsigned char *key_copy;
1323
1324 if( ( key_copy = mbedtls_calloc( 1, keylen ) ) == NULL )
1325 return( MBEDTLS_ERR_PK_ALLOC_FAILED );
1326
1327 memcpy( key_copy, key, keylen );
1328
1329 ret = pk_parse_key_pkcs8_encrypted_der( pk, key_copy, keylen,
1330 pwd, pwdlen, f_rng, p_rng );
1331
1332 mbedtls_platform_zeroize( key_copy, keylen );
1333 mbedtls_free( key_copy );
1334 }
1335
1336 if( ret == 0 )
1337 return( 0 );
1338
1339 mbedtls_pk_free( pk );
1340 mbedtls_pk_init( pk );
1341
1342 if( ret == MBEDTLS_ERR_PK_PASSWORD_MISMATCH )
1343 {
1344 return( ret );
1345 }
1346 #endif /* MBEDTLS_PKCS12_C || MBEDTLS_PKCS5_C */
1347
1348 ret = pk_parse_key_pkcs8_unencrypted_der( pk, key, keylen, f_rng, p_rng );
1349 if( ret == 0 )
1350 {
1351 return( 0 );
1352 }
1353
1354 mbedtls_pk_free( pk );
1355 mbedtls_pk_init( pk );
1356
1357 #if defined(MBEDTLS_RSA_C)
1358
1359 pk_info = mbedtls_pk_info_from_type( MBEDTLS_PK_RSA );
1360 if( mbedtls_pk_setup( pk, pk_info ) == 0 &&
1361 pk_parse_key_pkcs1_der( mbedtls_pk_rsa( *pk ), key, keylen ) == 0 )
1362 {
1363 return( 0 );
1364 }
1365
1366 mbedtls_pk_free( pk );
1367 mbedtls_pk_init( pk );
1368 #endif /* MBEDTLS_RSA_C */
1369
1370 #if defined(MBEDTLS_ECP_C)
1371 pk_info = mbedtls_pk_info_from_type( MBEDTLS_PK_ECKEY );
1372 if( mbedtls_pk_setup( pk, pk_info ) == 0 &&
1373 pk_parse_key_sec1_der( mbedtls_pk_ec( *pk ),
1374 key, keylen, f_rng, p_rng ) == 0 )
1375 {
1376 return( 0 );
1377 }
1378 mbedtls_pk_free( pk );
1379 #endif /* MBEDTLS_ECP_C */
1380
1381 /* If MBEDTLS_RSA_C is defined but MBEDTLS_ECP_C isn't,
1382 * it is ok to leave the PK context initialized but not
1383 * freed: It is the caller's responsibility to call pk_init()
1384 * before calling this function, and to call pk_free()
1385 * when it fails. If MBEDTLS_ECP_C is defined but MBEDTLS_RSA_C
1386 * isn't, this leads to mbedtls_pk_free() being called
1387 * twice, once here and once by the caller, but this is
1388 * also ok and in line with the mbedtls_pk_free() calls
1389 * on failed PEM parsing attempts. */
1390
1391 return( MBEDTLS_ERR_PK_KEY_INVALID_FORMAT );
1392 }
1393
1394 /*
1395 * Parse a public key
1396 */
mbedtls_pk_parse_public_key(mbedtls_pk_context * ctx,const unsigned char * key,size_t keylen)1397 int mbedtls_pk_parse_public_key( mbedtls_pk_context *ctx,
1398 const unsigned char *key, size_t keylen )
1399 {
1400 int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
1401 unsigned char *p;
1402 #if defined(MBEDTLS_RSA_C)
1403 const mbedtls_pk_info_t *pk_info;
1404 #endif
1405 #if defined(MBEDTLS_PEM_PARSE_C)
1406 size_t len;
1407 mbedtls_pem_context pem;
1408 #endif
1409
1410 if( keylen == 0 )
1411 return( MBEDTLS_ERR_PK_KEY_INVALID_FORMAT );
1412
1413 #if defined(MBEDTLS_PEM_PARSE_C)
1414 mbedtls_pem_init( &pem );
1415 #if defined(MBEDTLS_RSA_C)
1416 /* Avoid calling mbedtls_pem_read_buffer() on non-null-terminated string */
1417 if( key[keylen - 1] != '\0' )
1418 ret = MBEDTLS_ERR_PEM_NO_HEADER_FOOTER_PRESENT;
1419 else
1420 ret = mbedtls_pem_read_buffer( &pem,
1421 "-----BEGIN RSA PUBLIC KEY-----",
1422 "-----END RSA PUBLIC KEY-----",
1423 key, NULL, 0, &len );
1424
1425 if( ret == 0 )
1426 {
1427 p = pem.buf;
1428 if( ( pk_info = mbedtls_pk_info_from_type( MBEDTLS_PK_RSA ) ) == NULL )
1429 {
1430 mbedtls_pem_free( &pem );
1431 return( MBEDTLS_ERR_PK_UNKNOWN_PK_ALG );
1432 }
1433
1434 if( ( ret = mbedtls_pk_setup( ctx, pk_info ) ) != 0 )
1435 {
1436 mbedtls_pem_free( &pem );
1437 return( ret );
1438 }
1439
1440 if ( ( ret = pk_get_rsapubkey( &p, p + pem.buflen, mbedtls_pk_rsa( *ctx ) ) ) != 0 )
1441 mbedtls_pk_free( ctx );
1442
1443 mbedtls_pem_free( &pem );
1444 return( ret );
1445 }
1446 else if( ret != MBEDTLS_ERR_PEM_NO_HEADER_FOOTER_PRESENT )
1447 {
1448 mbedtls_pem_free( &pem );
1449 return( ret );
1450 }
1451 #endif /* MBEDTLS_RSA_C */
1452
1453 /* Avoid calling mbedtls_pem_read_buffer() on non-null-terminated string */
1454 if( key[keylen - 1] != '\0' )
1455 ret = MBEDTLS_ERR_PEM_NO_HEADER_FOOTER_PRESENT;
1456 else
1457 ret = mbedtls_pem_read_buffer( &pem,
1458 "-----BEGIN PUBLIC KEY-----",
1459 "-----END PUBLIC KEY-----",
1460 key, NULL, 0, &len );
1461
1462 if( ret == 0 )
1463 {
1464 /*
1465 * Was PEM encoded
1466 */
1467 p = pem.buf;
1468
1469 ret = mbedtls_pk_parse_subpubkey( &p, p + pem.buflen, ctx );
1470 mbedtls_pem_free( &pem );
1471 return( ret );
1472 }
1473 else if( ret != MBEDTLS_ERR_PEM_NO_HEADER_FOOTER_PRESENT )
1474 {
1475 mbedtls_pem_free( &pem );
1476 return( ret );
1477 }
1478 mbedtls_pem_free( &pem );
1479 #endif /* MBEDTLS_PEM_PARSE_C */
1480
1481 #if defined(MBEDTLS_RSA_C)
1482 if( ( pk_info = mbedtls_pk_info_from_type( MBEDTLS_PK_RSA ) ) == NULL )
1483 return( MBEDTLS_ERR_PK_UNKNOWN_PK_ALG );
1484
1485 if( ( ret = mbedtls_pk_setup( ctx, pk_info ) ) != 0 )
1486 return( ret );
1487
1488 p = (unsigned char *)key;
1489 ret = pk_get_rsapubkey( &p, p + keylen, mbedtls_pk_rsa( *ctx ) );
1490 if( ret == 0 )
1491 {
1492 return( ret );
1493 }
1494 mbedtls_pk_free( ctx );
1495 if( ret != ( MBEDTLS_ERROR_ADD( MBEDTLS_ERR_PK_INVALID_PUBKEY,
1496 MBEDTLS_ERR_ASN1_UNEXPECTED_TAG ) ) )
1497 {
1498 return( ret );
1499 }
1500 #endif /* MBEDTLS_RSA_C */
1501 p = (unsigned char *) key;
1502
1503 ret = mbedtls_pk_parse_subpubkey( &p, p + keylen, ctx );
1504
1505 return( ret );
1506 }
1507
1508 #endif /* MBEDTLS_PK_PARSE_C */
1509