• Home
  • Line#
  • Scopes#
  • Navigate#
  • Raw
  • Download
1 /**
2  * \file x509_crt.h
3  *
4  * \brief X.509 certificate parsing and writing
5  */
6 /*
7  *  Copyright The Mbed TLS Contributors
8  *  SPDX-License-Identifier: Apache-2.0 OR GPL-2.0-or-later
9  *
10  *  This file is provided under the Apache License 2.0, or the
11  *  GNU General Public License v2.0 or later.
12  *
13  *  **********
14  *  Apache License 2.0:
15  *
16  *  Licensed under the Apache License, Version 2.0 (the "License"); you may
17  *  not use this file except in compliance with the License.
18  *  You may obtain a copy of the License at
19  *
20  *  http://www.apache.org/licenses/LICENSE-2.0
21  *
22  *  Unless required by applicable law or agreed to in writing, software
23  *  distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
24  *  WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
25  *  See the License for the specific language governing permissions and
26  *  limitations under the License.
27  *
28  *  **********
29  *
30  *  **********
31  *  GNU General Public License v2.0 or later:
32  *
33  *  This program is free software; you can redistribute it and/or modify
34  *  it under the terms of the GNU General Public License as published by
35  *  the Free Software Foundation; either version 2 of the License, or
36  *  (at your option) any later version.
37  *
38  *  This program is distributed in the hope that it will be useful,
39  *  but WITHOUT ANY WARRANTY; without even the implied warranty of
40  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
41  *  GNU General Public License for more details.
42  *
43  *  You should have received a copy of the GNU General Public License along
44  *  with this program; if not, write to the Free Software Foundation, Inc.,
45  *  51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
46  *
47  *  **********
48  */
49 #ifndef MBEDTLS_X509_CRT_H
50 #define MBEDTLS_X509_CRT_H
51 
52 #if !defined(MBEDTLS_CONFIG_FILE)
53 #include "config.h"
54 #else
55 #include MBEDTLS_CONFIG_FILE
56 #endif
57 
58 #include "x509.h"
59 #include "x509_crl.h"
60 
61 /**
62  * \addtogroup x509_module
63  * \{
64  */
65 
66 #ifdef __cplusplus
67 extern "C" {
68 #endif
69 
70 /**
71  * \name Structures and functions for parsing and writing X.509 certificates
72  * \{
73  */
74 
75 /**
76  * Container for an X.509 certificate. The certificate may be chained.
77  */
78 typedef struct mbedtls_x509_crt
79 {
80     mbedtls_x509_buf raw;               /**< The raw certificate data (DER). */
81     mbedtls_x509_buf tbs;               /**< The raw certificate body (DER). The part that is To Be Signed. */
82 
83     int version;                /**< The X.509 version. (1=v1, 2=v2, 3=v3) */
84     mbedtls_x509_buf serial;            /**< Unique id for certificate issued by a specific CA. */
85     mbedtls_x509_buf sig_oid;           /**< Signature algorithm, e.g. sha1RSA */
86 
87     mbedtls_x509_buf issuer_raw;        /**< The raw issuer data (DER). Used for quick comparison. */
88     mbedtls_x509_buf subject_raw;       /**< The raw subject data (DER). Used for quick comparison. */
89 
90     mbedtls_x509_name issuer;           /**< The parsed issuer data (named information object). */
91     mbedtls_x509_name subject;          /**< The parsed subject data (named information object). */
92 
93     mbedtls_x509_time valid_from;       /**< Start time of certificate validity. */
94     mbedtls_x509_time valid_to;         /**< End time of certificate validity. */
95 
96     mbedtls_pk_context pk;              /**< Container for the public key context. */
97 
98     mbedtls_x509_buf issuer_id;         /**< Optional X.509 v2/v3 issuer unique identifier. */
99     mbedtls_x509_buf subject_id;        /**< Optional X.509 v2/v3 subject unique identifier. */
100     mbedtls_x509_buf v3_ext;            /**< Optional X.509 v3 extensions.  */
101     mbedtls_x509_sequence subject_alt_names;    /**< Optional list of Subject Alternative Names (Only dNSName supported). */
102 
103     int ext_types;              /**< Bit string containing detected and parsed extensions */
104     int ca_istrue;              /**< Optional Basic Constraint extension value: 1 if this certificate belongs to a CA, 0 otherwise. */
105     int max_pathlen;            /**< Optional Basic Constraint extension value: The maximum path length to the root certificate. Path length is 1 higher than RFC 5280 'meaning', so 1+ */
106 
107     unsigned int key_usage;     /**< Optional key usage extension value: See the values in x509.h */
108 
109     mbedtls_x509_sequence ext_key_usage; /**< Optional list of extended key usage OIDs. */
110 
111     unsigned char ns_cert_type; /**< Optional Netscape certificate type extension value: See the values in x509.h */
112 
113     mbedtls_x509_buf sig;               /**< Signature: hash of the tbs part signed with the private key. */
114     mbedtls_md_type_t sig_md;           /**< Internal representation of the MD algorithm of the signature algorithm, e.g. MBEDTLS_MD_SHA256 */
115     mbedtls_pk_type_t sig_pk;           /**< Internal representation of the Public Key algorithm of the signature algorithm, e.g. MBEDTLS_PK_RSA */
116     void *sig_opts;             /**< Signature options to be passed to mbedtls_pk_verify_ext(), e.g. for RSASSA-PSS */
117 
118     struct mbedtls_x509_crt *next;     /**< Next certificate in the CA-chain. */
119 }
120 mbedtls_x509_crt;
121 
122 /**
123  * Build flag from an algorithm/curve identifier (pk, md, ecp)
124  * Since 0 is always XXX_NONE, ignore it.
125  */
126 #define MBEDTLS_X509_ID_FLAG( id )   ( 1 << ( (id) - 1 ) )
127 
128 /**
129  * Security profile for certificate verification.
130  *
131  * All lists are bitfields, built by ORing flags from MBEDTLS_X509_ID_FLAG().
132  */
133 typedef struct mbedtls_x509_crt_profile
134 {
135     uint32_t allowed_mds;       /**< MDs for signatures         */
136     uint32_t allowed_pks;       /**< PK algs for signatures     */
137     uint32_t allowed_curves;    /**< Elliptic curves for ECDSA  */
138     uint32_t rsa_min_bitlen;    /**< Minimum size for RSA keys  */
139 }
140 mbedtls_x509_crt_profile;
141 
142 #define MBEDTLS_X509_CRT_VERSION_1              0
143 #define MBEDTLS_X509_CRT_VERSION_2              1
144 #define MBEDTLS_X509_CRT_VERSION_3              2
145 
146 #define MBEDTLS_X509_RFC5280_MAX_SERIAL_LEN 32
147 #define MBEDTLS_X509_RFC5280_UTC_TIME_LEN   15
148 
149 #if !defined( MBEDTLS_X509_MAX_FILE_PATH_LEN )
150 #define MBEDTLS_X509_MAX_FILE_PATH_LEN 512
151 #endif
152 
153 /**
154  * Container for writing a certificate (CRT)
155  */
156 typedef struct mbedtls_x509write_cert
157 {
158     int version;
159     mbedtls_mpi serial;
160     mbedtls_pk_context *subject_key;
161     mbedtls_pk_context *issuer_key;
162     mbedtls_asn1_named_data *subject;
163     mbedtls_asn1_named_data *issuer;
164     mbedtls_md_type_t md_alg;
165     char not_before[MBEDTLS_X509_RFC5280_UTC_TIME_LEN + 1];
166     char not_after[MBEDTLS_X509_RFC5280_UTC_TIME_LEN + 1];
167     mbedtls_asn1_named_data *extensions;
168 }
169 mbedtls_x509write_cert;
170 
171 /**
172  * Item in a verification chain: cert and flags for it
173  */
174 typedef struct {
175     mbedtls_x509_crt *crt;
176     uint32_t flags;
177 } mbedtls_x509_crt_verify_chain_item;
178 
179 /**
180  * Max size of verification chain: end-entity + intermediates + trusted root
181  */
182 #define MBEDTLS_X509_MAX_VERIFY_CHAIN_SIZE  ( MBEDTLS_X509_MAX_INTERMEDIATE_CA + 2 )
183 
184 /**
185  * Verification chain as built by \c mbedtls_crt_verify_chain()
186  */
187 typedef struct
188 {
189     mbedtls_x509_crt_verify_chain_item items[MBEDTLS_X509_MAX_VERIFY_CHAIN_SIZE];
190     unsigned len;
191 } mbedtls_x509_crt_verify_chain;
192 
193 #if defined(MBEDTLS_ECDSA_C) && defined(MBEDTLS_ECP_RESTARTABLE)
194 
195 /**
196  * \brief       Context for resuming X.509 verify operations
197  */
198 typedef struct
199 {
200     /* for check_signature() */
201     mbedtls_pk_restart_ctx pk;
202 
203     /* for find_parent_in() */
204     mbedtls_x509_crt *parent; /* non-null iff parent_in in progress */
205     mbedtls_x509_crt *fallback_parent;
206     int fallback_signature_is_good;
207 
208     /* for find_parent() */
209     int parent_is_trusted; /* -1 if find_parent is not in progress */
210 
211     /* for verify_chain() */
212     enum {
213         x509_crt_rs_none,
214         x509_crt_rs_find_parent,
215     } in_progress;  /* none if no operation is in progress */
216     int self_cnt;
217     mbedtls_x509_crt_verify_chain ver_chain;
218 
219 } mbedtls_x509_crt_restart_ctx;
220 
221 #else /* MBEDTLS_ECDSA_C && MBEDTLS_ECP_RESTARTABLE */
222 
223 /* Now we can declare functions that take a pointer to that */
224 typedef void mbedtls_x509_crt_restart_ctx;
225 
226 #endif /* MBEDTLS_ECDSA_C && MBEDTLS_ECP_RESTARTABLE */
227 
228 #if defined(MBEDTLS_X509_CRT_PARSE_C)
229 /**
230  * Default security profile. Should provide a good balance between security
231  * and compatibility with current deployments.
232  */
233 extern const mbedtls_x509_crt_profile mbedtls_x509_crt_profile_default;
234 
235 /**
236  * Expected next default profile. Recommended for new deployments.
237  * Currently targets a 128-bit security level, except for RSA-2048.
238  */
239 extern const mbedtls_x509_crt_profile mbedtls_x509_crt_profile_next;
240 
241 /**
242  * NSA Suite B profile.
243  */
244 extern const mbedtls_x509_crt_profile mbedtls_x509_crt_profile_suiteb;
245 
246 /**
247  * \brief          Parse a single DER formatted certificate and add it
248  *                 to the chained list.
249  *
250  * \param chain    points to the start of the chain
251  * \param buf      buffer holding the certificate DER data
252  * \param buflen   size of the buffer
253  *
254  * \return         0 if successful, or a specific X509 or PEM error code
255  */
256 int mbedtls_x509_crt_parse_der( mbedtls_x509_crt *chain, const unsigned char *buf,
257                         size_t buflen );
258 
259 /**
260  * \brief          Parse one DER-encoded or one or more concatenated PEM-encoded
261  *                 certificates and add them to the chained list.
262  *
263  *                 For CRTs in PEM encoding, the function parses permissively:
264  *                 if at least one certificate can be parsed, the function
265  *                 returns the number of certificates for which parsing failed
266  *                 (hence \c 0 if all certificates were parsed successfully).
267  *                 If no certificate could be parsed, the function returns
268  *                 the first (negative) error encountered during parsing.
269  *
270  *                 PEM encoded certificates may be interleaved by other data
271  *                 such as human readable descriptions of their content, as
272  *                 long as the certificates are enclosed in the PEM specific
273  *                 '-----{BEGIN/END} CERTIFICATE-----' delimiters.
274  *
275  * \param chain    The chain to which to add the parsed certificates.
276  * \param buf      The buffer holding the certificate data in PEM or DER format.
277  *                 For certificates in PEM encoding, this may be a concatenation
278  *                 of multiple certificates; for DER encoding, the buffer must
279  *                 comprise exactly one certificate.
280  * \param buflen   The size of \p buf, including the terminating \c NULL byte
281  *                 in case of PEM encoded data.
282  *
283  * \return         \c 0 if all certificates were parsed successfully.
284  * \return         The (positive) number of certificates that couldn't
285  *                 be parsed if parsing was partly successful (see above).
286  * \return         A negative X509 or PEM error code otherwise.
287  *
288  */
289 int mbedtls_x509_crt_parse( mbedtls_x509_crt *chain, const unsigned char *buf, size_t buflen );
290 
291 #if defined(MBEDTLS_FS_IO)
292 /**
293  * \brief          Load one or more certificates and add them
294  *                 to the chained list. Parses permissively. If some
295  *                 certificates can be parsed, the result is the number
296  *                 of failed certificates it encountered. If none complete
297  *                 correctly, the first error is returned.
298  *
299  * \param chain    points to the start of the chain
300  * \param path     filename to read the certificates from
301  *
302  * \return         0 if all certificates parsed successfully, a positive number
303  *                 if partly successful or a specific X509 or PEM error code
304  */
305 int mbedtls_x509_crt_parse_file( mbedtls_x509_crt *chain, const char *path );
306 
307 /**
308  * \brief          Load one or more certificate files from a path and add them
309  *                 to the chained list. Parses permissively. If some
310  *                 certificates can be parsed, the result is the number
311  *                 of failed certificates it encountered. If none complete
312  *                 correctly, the first error is returned.
313  *
314  * \param chain    points to the start of the chain
315  * \param path     directory / folder to read the certificate files from
316  *
317  * \return         0 if all certificates parsed successfully, a positive number
318  *                 if partly successful or a specific X509 or PEM error code
319  */
320 int mbedtls_x509_crt_parse_path( mbedtls_x509_crt *chain, const char *path );
321 #endif /* MBEDTLS_FS_IO */
322 
323 /**
324  * \brief          Returns an informational string about the
325  *                 certificate.
326  *
327  * \param buf      Buffer to write to
328  * \param size     Maximum size of buffer
329  * \param prefix   A line prefix
330  * \param crt      The X509 certificate to represent
331  *
332  * \return         The length of the string written (not including the
333  *                 terminated nul byte), or a negative error code.
334  */
335 int mbedtls_x509_crt_info( char *buf, size_t size, const char *prefix,
336                    const mbedtls_x509_crt *crt );
337 
338 /**
339  * \brief          Returns an informational string about the
340  *                 verification status of a certificate.
341  *
342  * \param buf      Buffer to write to
343  * \param size     Maximum size of buffer
344  * \param prefix   A line prefix
345  * \param flags    Verification flags created by mbedtls_x509_crt_verify()
346  *
347  * \return         The length of the string written (not including the
348  *                 terminated nul byte), or a negative error code.
349  */
350 int mbedtls_x509_crt_verify_info( char *buf, size_t size, const char *prefix,
351                           uint32_t flags );
352 
353 /**
354  * \brief          Verify the certificate signature
355  *
356  *                 The verify callback is a user-supplied callback that
357  *                 can clear / modify / add flags for a certificate. If set,
358  *                 the verification callback is called for each
359  *                 certificate in the chain (from the trust-ca down to the
360  *                 presented crt). The parameters for the callback are:
361  *                 (void *parameter, mbedtls_x509_crt *crt, int certificate_depth,
362  *                 int *flags). With the flags representing current flags for
363  *                 that specific certificate and the certificate depth from
364  *                 the bottom (Peer cert depth = 0).
365  *
366  *                 All flags left after returning from the callback
367  *                 are also returned to the application. The function should
368  *                 return 0 for anything (including invalid certificates)
369  *                 other than fatal error, as a non-zero return code
370  *                 immediately aborts the verification process. For fatal
371  *                 errors, a specific error code should be used (different
372  *                 from MBEDTLS_ERR_X509_CERT_VERIFY_FAILED which should not
373  *                 be returned at this point), or MBEDTLS_ERR_X509_FATAL_ERROR
374  *                 can be used if no better code is available.
375  *
376  * \note           In case verification failed, the results can be displayed
377  *                 using \c mbedtls_x509_crt_verify_info()
378  *
379  * \note           Same as \c mbedtls_x509_crt_verify_with_profile() with the
380  *                 default security profile.
381  *
382  * \note           It is your responsibility to provide up-to-date CRLs for
383  *                 all trusted CAs. If no CRL is provided for the CA that was
384  *                 used to sign the certificate, CRL verification is skipped
385  *                 silently, that is *without* setting any flag.
386  *
387  * \note           The \c trust_ca list can contain two types of certificates:
388  *                 (1) those of trusted root CAs, so that certificates
389  *                 chaining up to those CAs will be trusted, and (2)
390  *                 self-signed end-entity certificates to be trusted (for
391  *                 specific peers you know) - in that case, the self-signed
392  *                 certificate doesn't need to have the CA bit set.
393  *
394  * \param crt      a certificate (chain) to be verified
395  * \param trust_ca the list of trusted CAs (see note above)
396  * \param ca_crl   the list of CRLs for trusted CAs (see note above)
397  * \param cn       expected Common Name (can be set to
398  *                 NULL if the CN must not be verified)
399  * \param flags    result of the verification
400  * \param f_vrfy   verification function
401  * \param p_vrfy   verification parameter
402  *
403  * \return         0 (and flags set to 0) if the chain was verified and valid,
404  *                 MBEDTLS_ERR_X509_CERT_VERIFY_FAILED if the chain was verified
405  *                 but found to be invalid, in which case *flags will have one
406  *                 or more MBEDTLS_X509_BADCERT_XXX or MBEDTLS_X509_BADCRL_XXX
407  *                 flags set, or another error (and flags set to 0xffffffff)
408  *                 in case of a fatal error encountered during the
409  *                 verification process.
410  */
411 int mbedtls_x509_crt_verify( mbedtls_x509_crt *crt,
412                      mbedtls_x509_crt *trust_ca,
413                      mbedtls_x509_crl *ca_crl,
414                      const char *cn, uint32_t *flags,
415                      int (*f_vrfy)(void *, mbedtls_x509_crt *, int, uint32_t *),
416                      void *p_vrfy );
417 
418 /**
419  * \brief          Verify the certificate signature according to profile
420  *
421  * \note           Same as \c mbedtls_x509_crt_verify(), but with explicit
422  *                 security profile.
423  *
424  * \note           The restrictions on keys (RSA minimum size, allowed curves
425  *                 for ECDSA) apply to all certificates: trusted root,
426  *                 intermediate CAs if any, and end entity certificate.
427  *
428  * \param crt      a certificate (chain) to be verified
429  * \param trust_ca the list of trusted CAs
430  * \param ca_crl   the list of CRLs for trusted CAs
431  * \param profile  security profile for verification
432  * \param cn       expected Common Name (can be set to
433  *                 NULL if the CN must not be verified)
434  * \param flags    result of the verification
435  * \param f_vrfy   verification function
436  * \param p_vrfy   verification parameter
437  *
438  * \return         0 if successful or MBEDTLS_ERR_X509_CERT_VERIFY_FAILED
439  *                 in which case *flags will have one or more
440  *                 MBEDTLS_X509_BADCERT_XXX or MBEDTLS_X509_BADCRL_XXX flags
441  *                 set,
442  *                 or another error in case of a fatal error encountered
443  *                 during the verification process.
444  */
445 int mbedtls_x509_crt_verify_with_profile( mbedtls_x509_crt *crt,
446                      mbedtls_x509_crt *trust_ca,
447                      mbedtls_x509_crl *ca_crl,
448                      const mbedtls_x509_crt_profile *profile,
449                      const char *cn, uint32_t *flags,
450                      int (*f_vrfy)(void *, mbedtls_x509_crt *, int, uint32_t *),
451                      void *p_vrfy );
452 
453 /**
454  * \brief          Restartable version of \c mbedtls_crt_verify_with_profile()
455  *
456  * \note           Performs the same job as \c mbedtls_crt_verify_with_profile()
457  *                 but can return early and restart according to the limit
458  *                 set with \c mbedtls_ecp_set_max_ops() to reduce blocking.
459  *
460  * \param crt      a certificate (chain) to be verified
461  * \param trust_ca the list of trusted CAs
462  * \param ca_crl   the list of CRLs for trusted CAs
463  * \param profile  security profile for verification
464  * \param cn       expected Common Name (can be set to
465  *                 NULL if the CN must not be verified)
466  * \param flags    result of the verification
467  * \param f_vrfy   verification function
468  * \param p_vrfy   verification parameter
469  * \param rs_ctx   restart context (NULL to disable restart)
470  *
471  * \return         See \c mbedtls_crt_verify_with_profile(), or
472  * \return         #MBEDTLS_ERR_ECP_IN_PROGRESS if maximum number of
473  *                 operations was reached: see \c mbedtls_ecp_set_max_ops().
474  */
475 int mbedtls_x509_crt_verify_restartable( mbedtls_x509_crt *crt,
476                      mbedtls_x509_crt *trust_ca,
477                      mbedtls_x509_crl *ca_crl,
478                      const mbedtls_x509_crt_profile *profile,
479                      const char *cn, uint32_t *flags,
480                      int (*f_vrfy)(void *, mbedtls_x509_crt *, int, uint32_t *),
481                      void *p_vrfy,
482                      mbedtls_x509_crt_restart_ctx *rs_ctx );
483 
484 #if defined(MBEDTLS_X509_CHECK_KEY_USAGE)
485 /**
486  * \brief          Check usage of certificate against keyUsage extension.
487  *
488  * \param crt      Leaf certificate used.
489  * \param usage    Intended usage(s) (eg MBEDTLS_X509_KU_KEY_ENCIPHERMENT
490  *                 before using the certificate to perform an RSA key
491  *                 exchange).
492  *
493  * \note           Except for decipherOnly and encipherOnly, a bit set in the
494  *                 usage argument means this bit MUST be set in the
495  *                 certificate. For decipherOnly and encipherOnly, it means
496  *                 that bit MAY be set.
497  *
498  * \return         0 is these uses of the certificate are allowed,
499  *                 MBEDTLS_ERR_X509_BAD_INPUT_DATA if the keyUsage extension
500  *                 is present but does not match the usage argument.
501  *
502  * \note           You should only call this function on leaf certificates, on
503  *                 (intermediate) CAs the keyUsage extension is automatically
504  *                 checked by \c mbedtls_x509_crt_verify().
505  */
506 int mbedtls_x509_crt_check_key_usage( const mbedtls_x509_crt *crt,
507                                       unsigned int usage );
508 #endif /* MBEDTLS_X509_CHECK_KEY_USAGE) */
509 
510 #if defined(MBEDTLS_X509_CHECK_EXTENDED_KEY_USAGE)
511 /**
512  * \brief           Check usage of certificate against extendedKeyUsage.
513  *
514  * \param crt       Leaf certificate used.
515  * \param usage_oid Intended usage (eg MBEDTLS_OID_SERVER_AUTH or
516  *                  MBEDTLS_OID_CLIENT_AUTH).
517  * \param usage_len Length of usage_oid (eg given by MBEDTLS_OID_SIZE()).
518  *
519  * \return          0 if this use of the certificate is allowed,
520  *                  MBEDTLS_ERR_X509_BAD_INPUT_DATA if not.
521  *
522  * \note            Usually only makes sense on leaf certificates.
523  */
524 int mbedtls_x509_crt_check_extended_key_usage( const mbedtls_x509_crt *crt,
525                                                const char *usage_oid,
526                                                size_t usage_len );
527 #endif /* MBEDTLS_X509_CHECK_EXTENDED_KEY_USAGE */
528 
529 #if defined(MBEDTLS_X509_CRL_PARSE_C)
530 /**
531  * \brief          Verify the certificate revocation status
532  *
533  * \param crt      a certificate to be verified
534  * \param crl      the CRL to verify against
535  *
536  * \return         1 if the certificate is revoked, 0 otherwise
537  *
538  */
539 int mbedtls_x509_crt_is_revoked( const mbedtls_x509_crt *crt, const mbedtls_x509_crl *crl );
540 #endif /* MBEDTLS_X509_CRL_PARSE_C */
541 
542 /**
543  * \brief          Initialize a certificate (chain)
544  *
545  * \param crt      Certificate chain to initialize
546  */
547 void mbedtls_x509_crt_init( mbedtls_x509_crt *crt );
548 
549 /**
550  * \brief          Unallocate all certificate data
551  *
552  * \param crt      Certificate chain to free
553  */
554 void mbedtls_x509_crt_free( mbedtls_x509_crt *crt );
555 
556 #if defined(MBEDTLS_ECDSA_C) && defined(MBEDTLS_ECP_RESTARTABLE)
557 /**
558  * \brief           Initialize a restart context
559  */
560 void mbedtls_x509_crt_restart_init( mbedtls_x509_crt_restart_ctx *ctx );
561 
562 /**
563  * \brief           Free the components of a restart context
564  */
565 void mbedtls_x509_crt_restart_free( mbedtls_x509_crt_restart_ctx *ctx );
566 #endif /* MBEDTLS_ECDSA_C && MBEDTLS_ECP_RESTARTABLE */
567 #endif /* MBEDTLS_X509_CRT_PARSE_C */
568 
569 /* \} name */
570 /* \} addtogroup x509_module */
571 
572 #if defined(MBEDTLS_X509_CRT_WRITE_C)
573 /**
574  * \brief           Initialize a CRT writing context
575  *
576  * \param ctx       CRT context to initialize
577  */
578 void mbedtls_x509write_crt_init( mbedtls_x509write_cert *ctx );
579 
580 /**
581  * \brief           Set the verion for a Certificate
582  *                  Default: MBEDTLS_X509_CRT_VERSION_3
583  *
584  * \param ctx       CRT context to use
585  * \param version   version to set (MBEDTLS_X509_CRT_VERSION_1, MBEDTLS_X509_CRT_VERSION_2 or
586  *                                  MBEDTLS_X509_CRT_VERSION_3)
587  */
588 void mbedtls_x509write_crt_set_version( mbedtls_x509write_cert *ctx, int version );
589 
590 /**
591  * \brief           Set the serial number for a Certificate.
592  *
593  * \param ctx       CRT context to use
594  * \param serial    serial number to set
595  *
596  * \return          0 if successful
597  */
598 int mbedtls_x509write_crt_set_serial( mbedtls_x509write_cert *ctx, const mbedtls_mpi *serial );
599 
600 /**
601  * \brief           Set the validity period for a Certificate
602  *                  Timestamps should be in string format for UTC timezone
603  *                  i.e. "YYYYMMDDhhmmss"
604  *                  e.g. "20131231235959" for December 31st 2013
605  *                       at 23:59:59
606  *
607  * \param ctx       CRT context to use
608  * \param not_before    not_before timestamp
609  * \param not_after     not_after timestamp
610  *
611  * \return          0 if timestamp was parsed successfully, or
612  *                  a specific error code
613  */
614 int mbedtls_x509write_crt_set_validity( mbedtls_x509write_cert *ctx, const char *not_before,
615                                 const char *not_after );
616 
617 /**
618  * \brief           Set the issuer name for a Certificate
619  *                  Issuer names should contain a comma-separated list
620  *                  of OID types and values:
621  *                  e.g. "C=UK,O=ARM,CN=mbed TLS CA"
622  *
623  * \param ctx           CRT context to use
624  * \param issuer_name   issuer name to set
625  *
626  * \return          0 if issuer name was parsed successfully, or
627  *                  a specific error code
628  */
629 int mbedtls_x509write_crt_set_issuer_name( mbedtls_x509write_cert *ctx,
630                                    const char *issuer_name );
631 
632 /**
633  * \brief           Set the subject name for a Certificate
634  *                  Subject names should contain a comma-separated list
635  *                  of OID types and values:
636  *                  e.g. "C=UK,O=ARM,CN=mbed TLS Server 1"
637  *
638  * \param ctx           CRT context to use
639  * \param subject_name  subject name to set
640  *
641  * \return          0 if subject name was parsed successfully, or
642  *                  a specific error code
643  */
644 int mbedtls_x509write_crt_set_subject_name( mbedtls_x509write_cert *ctx,
645                                     const char *subject_name );
646 
647 /**
648  * \brief           Set the subject public key for the certificate
649  *
650  * \param ctx       CRT context to use
651  * \param key       public key to include
652  */
653 void mbedtls_x509write_crt_set_subject_key( mbedtls_x509write_cert *ctx, mbedtls_pk_context *key );
654 
655 /**
656  * \brief           Set the issuer key used for signing the certificate
657  *
658  * \param ctx       CRT context to use
659  * \param key       private key to sign with
660  */
661 void mbedtls_x509write_crt_set_issuer_key( mbedtls_x509write_cert *ctx, mbedtls_pk_context *key );
662 
663 /**
664  * \brief           Set the MD algorithm to use for the signature
665  *                  (e.g. MBEDTLS_MD_SHA1)
666  *
667  * \param ctx       CRT context to use
668  * \param md_alg    MD algorithm to use
669  */
670 void mbedtls_x509write_crt_set_md_alg( mbedtls_x509write_cert *ctx, mbedtls_md_type_t md_alg );
671 
672 /**
673  * \brief           Generic function to add to or replace an extension in the
674  *                  CRT
675  *
676  * \param ctx       CRT context to use
677  * \param oid       OID of the extension
678  * \param oid_len   length of the OID
679  * \param critical  if the extension is critical (per the RFC's definition)
680  * \param val       value of the extension OCTET STRING
681  * \param val_len   length of the value data
682  *
683  * \return          0 if successful, or a MBEDTLS_ERR_X509_ALLOC_FAILED
684  */
685 int mbedtls_x509write_crt_set_extension( mbedtls_x509write_cert *ctx,
686                                  const char *oid, size_t oid_len,
687                                  int critical,
688                                  const unsigned char *val, size_t val_len );
689 
690 /**
691  * \brief           Set the basicConstraints extension for a CRT
692  *
693  * \param ctx       CRT context to use
694  * \param is_ca     is this a CA certificate
695  * \param max_pathlen   maximum length of certificate chains below this
696  *                      certificate (only for CA certificates, -1 is
697  *                      inlimited)
698  *
699  * \return          0 if successful, or a MBEDTLS_ERR_X509_ALLOC_FAILED
700  */
701 int mbedtls_x509write_crt_set_basic_constraints( mbedtls_x509write_cert *ctx,
702                                          int is_ca, int max_pathlen );
703 
704 #if defined(MBEDTLS_SHA1_C)
705 /**
706  * \brief           Set the subjectKeyIdentifier extension for a CRT
707  *                  Requires that mbedtls_x509write_crt_set_subject_key() has been
708  *                  called before
709  *
710  * \param ctx       CRT context to use
711  *
712  * \return          0 if successful, or a MBEDTLS_ERR_X509_ALLOC_FAILED
713  */
714 int mbedtls_x509write_crt_set_subject_key_identifier( mbedtls_x509write_cert *ctx );
715 
716 /**
717  * \brief           Set the authorityKeyIdentifier extension for a CRT
718  *                  Requires that mbedtls_x509write_crt_set_issuer_key() has been
719  *                  called before
720  *
721  * \param ctx       CRT context to use
722  *
723  * \return          0 if successful, or a MBEDTLS_ERR_X509_ALLOC_FAILED
724  */
725 int mbedtls_x509write_crt_set_authority_key_identifier( mbedtls_x509write_cert *ctx );
726 #endif /* MBEDTLS_SHA1_C */
727 
728 /**
729  * \brief           Set the Key Usage Extension flags
730  *                  (e.g. MBEDTLS_X509_KU_DIGITAL_SIGNATURE | MBEDTLS_X509_KU_KEY_CERT_SIGN)
731  *
732  * \param ctx       CRT context to use
733  * \param key_usage key usage flags to set
734  *
735  * \return          0 if successful, or MBEDTLS_ERR_X509_ALLOC_FAILED
736  */
737 int mbedtls_x509write_crt_set_key_usage( mbedtls_x509write_cert *ctx,
738                                          unsigned int key_usage );
739 
740 /**
741  * \brief           Set the Netscape Cert Type flags
742  *                  (e.g. MBEDTLS_X509_NS_CERT_TYPE_SSL_CLIENT | MBEDTLS_X509_NS_CERT_TYPE_EMAIL)
743  *
744  * \param ctx           CRT context to use
745  * \param ns_cert_type  Netscape Cert Type flags to set
746  *
747  * \return          0 if successful, or MBEDTLS_ERR_X509_ALLOC_FAILED
748  */
749 int mbedtls_x509write_crt_set_ns_cert_type( mbedtls_x509write_cert *ctx,
750                                     unsigned char ns_cert_type );
751 
752 /**
753  * \brief           Free the contents of a CRT write context
754  *
755  * \param ctx       CRT context to free
756  */
757 void mbedtls_x509write_crt_free( mbedtls_x509write_cert *ctx );
758 
759 /**
760  * \brief           Write a built up certificate to a X509 DER structure
761  *                  Note: data is written at the end of the buffer! Use the
762  *                        return value to determine where you should start
763  *                        using the buffer
764  *
765  * \param ctx       certificate to write away
766  * \param buf       buffer to write to
767  * \param size      size of the buffer
768  * \param f_rng     RNG function (for signature, see note)
769  * \param p_rng     RNG parameter
770  *
771  * \return          length of data written if successful, or a specific
772  *                  error code
773  *
774  * \note            f_rng may be NULL if RSA is used for signature and the
775  *                  signature is made offline (otherwise f_rng is desirable
776  *                  for countermeasures against timing attacks).
777  *                  ECDSA signatures always require a non-NULL f_rng.
778  */
779 int mbedtls_x509write_crt_der( mbedtls_x509write_cert *ctx, unsigned char *buf, size_t size,
780                        int (*f_rng)(void *, unsigned char *, size_t),
781                        void *p_rng );
782 
783 #if defined(MBEDTLS_PEM_WRITE_C)
784 /**
785  * \brief           Write a built up certificate to a X509 PEM string
786  *
787  * \param ctx       certificate to write away
788  * \param buf       buffer to write to
789  * \param size      size of the buffer
790  * \param f_rng     RNG function (for signature, see note)
791  * \param p_rng     RNG parameter
792  *
793  * \return          0 if successful, or a specific error code
794  *
795  * \note            f_rng may be NULL if RSA is used for signature and the
796  *                  signature is made offline (otherwise f_rng is desirable
797  *                  for countermeasures against timing attacks).
798  *                  ECDSA signatures always require a non-NULL f_rng.
799  */
800 int mbedtls_x509write_crt_pem( mbedtls_x509write_cert *ctx, unsigned char *buf, size_t size,
801                        int (*f_rng)(void *, unsigned char *, size_t),
802                        void *p_rng );
803 #endif /* MBEDTLS_PEM_WRITE_C */
804 #endif /* MBEDTLS_X509_CRT_WRITE_C */
805 
806 #ifdef __cplusplus
807 }
808 #endif
809 
810 #endif /* mbedtls_x509_crt.h */
811