4 * \brief X.509 certificate parsing and writing
6 * Copyright (C) 2006-2015, ARM Limited, All Rights Reserved
7 * SPDX-License-Identifier: Apache-2.0
9 * Licensed under the Apache License, Version 2.0 (the "License"); you may
10 * not use this file except in compliance with the License.
11 * You may obtain a copy of the License at
13 * http://www.apache.org/licenses/LICENSE-2.0
15 * Unless required by applicable law or agreed to in writing, software
16 * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
17 * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
18 * See the License for the specific language governing permissions and
19 * limitations under the License.
21 * This file is part of mbed TLS (https://tls.mbed.org)
23 #ifndef MBEDTLS_X509_CRT_H
24 #define MBEDTLS_X509_CRT_H
26 #if !defined(MBEDTLS_CONFIG_FILE)
29 #include MBEDTLS_CONFIG_FILE
36 * \addtogroup x509_module
45 * \name Structures and functions for parsing and writing X.509 certificates
50 * Container for an X.509 certificate. The certificate may be chained.
52 typedef struct mbedtls_x509_crt
54 mbedtls_x509_buf raw; /**< The raw certificate data (DER). */
55 mbedtls_x509_buf tbs; /**< The raw certificate body (DER). The part that is To Be Signed. */
57 int version; /**< The X.509 version. (1=v1, 2=v2, 3=v3) */
58 mbedtls_x509_buf serial; /**< Unique id for certificate issued by a specific CA. */
59 mbedtls_x509_buf sig_oid; /**< Signature algorithm, e.g. sha1RSA */
61 mbedtls_x509_buf issuer_raw; /**< The raw issuer data (DER). Used for quick comparison. */
62 mbedtls_x509_buf subject_raw; /**< The raw subject data (DER). Used for quick comparison. */
64 mbedtls_x509_name issuer; /**< The parsed issuer data (named information object). */
65 mbedtls_x509_name subject; /**< The parsed subject data (named information object). */
67 mbedtls_x509_time valid_from; /**< Start time of certificate validity. */
68 mbedtls_x509_time valid_to; /**< End time of certificate validity. */
70 mbedtls_pk_context pk; /**< Container for the public key context. */
72 mbedtls_x509_buf issuer_id; /**< Optional X.509 v2/v3 issuer unique identifier. */
73 mbedtls_x509_buf subject_id; /**< Optional X.509 v2/v3 subject unique identifier. */
74 mbedtls_x509_buf v3_ext; /**< Optional X.509 v3 extensions. */
75 mbedtls_x509_sequence subject_alt_names; /**< Optional list of Subject Alternative Names (Only dNSName supported). */
77 int ext_types; /**< Bit string containing detected and parsed extensions */
78 int ca_istrue; /**< Optional Basic Constraint extension value: 1 if this certificate belongs to a CA, 0 otherwise. */
79 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+ */
81 unsigned int key_usage; /**< Optional key usage extension value: See the values in x509.h */
83 mbedtls_x509_sequence ext_key_usage; /**< Optional list of extended key usage OIDs. */
85 unsigned char ns_cert_type; /**< Optional Netscape certificate type extension value: See the values in x509.h */
87 mbedtls_x509_buf sig; /**< Signature: hash of the tbs part signed with the private key. */
88 mbedtls_md_type_t sig_md; /**< Internal representation of the MD algorithm of the signature algorithm, e.g. MBEDTLS_MD_SHA256 */
89 mbedtls_pk_type_t sig_pk; /**< Internal representation of the Public Key algorithm of the signature algorithm, e.g. MBEDTLS_PK_RSA */
90 void *sig_opts; /**< Signature options to be passed to mbedtls_pk_verify_ext(), e.g. for RSASSA-PSS */
92 struct mbedtls_x509_crt *next; /**< Next certificate in the CA-chain. */
97 * Build flag from an algorithm/curve identifier (pk, md, ecp)
98 * Since 0 is always XXX_NONE, ignore it.
100 #define MBEDTLS_X509_ID_FLAG( id ) ( 1 << ( id - 1 ) )
103 * Security profile for certificate verification.
105 * All lists are bitfields, built by ORing flags from MBEDTLS_X509_ID_FLAG().
109 uint32_t allowed_mds; /**< MDs for signatures */
110 uint32_t allowed_pks; /**< PK algs for signatures */
111 uint32_t allowed_curves; /**< Elliptic curves for ECDSA */
112 uint32_t rsa_min_bitlen; /**< Minimum size for RSA keys */
114 mbedtls_x509_crt_profile;
116 #define MBEDTLS_X509_CRT_VERSION_1 0
117 #define MBEDTLS_X509_CRT_VERSION_2 1
118 #define MBEDTLS_X509_CRT_VERSION_3 2
120 #define MBEDTLS_X509_RFC5280_MAX_SERIAL_LEN 32
121 #define MBEDTLS_X509_RFC5280_UTC_TIME_LEN 15
123 #if !defined( MBEDTLS_X509_MAX_FILE_PATH_LEN )
124 #define MBEDTLS_X509_MAX_FILE_PATH_LEN 512
128 * Container for writing a certificate (CRT)
130 typedef struct mbedtls_x509write_cert
134 mbedtls_pk_context *subject_key;
135 mbedtls_pk_context *issuer_key;
136 mbedtls_asn1_named_data *subject;
137 mbedtls_asn1_named_data *issuer;
138 mbedtls_md_type_t md_alg;
139 char not_before[MBEDTLS_X509_RFC5280_UTC_TIME_LEN + 1];
140 char not_after[MBEDTLS_X509_RFC5280_UTC_TIME_LEN + 1];
141 mbedtls_asn1_named_data *extensions;
143 mbedtls_x509write_cert;
145 #if defined(MBEDTLS_X509_CRT_PARSE_C)
147 * Default security profile. Should provide a good balance between security
148 * and compatibility with current deployments.
150 extern const mbedtls_x509_crt_profile mbedtls_x509_crt_profile_default;
153 * Expected next default profile. Recommended for new deployments.
154 * Currently targets a 128-bit security level, except for RSA-2048.
156 extern const mbedtls_x509_crt_profile mbedtls_x509_crt_profile_next;
159 * NSA Suite B profile.
161 extern const mbedtls_x509_crt_profile mbedtls_x509_crt_profile_suiteb;
164 * \brief Parse a single DER formatted certificate and add it
165 * to the chained list.
167 * \param chain points to the start of the chain
168 * \param buf buffer holding the certificate DER data
169 * \param buflen size of the buffer
171 * \return 0 if successful, or a specific X509 or PEM error code
173 int mbedtls_x509_crt_parse_der( mbedtls_x509_crt *chain, const unsigned char *buf,
177 * \brief Parse one or more certificates and add them
178 * to the chained list. Parses permissively. If some
179 * certificates can be parsed, the result is the number
180 * of failed certificates it encountered. If none complete
181 * correctly, the first error is returned.
183 * \param chain points to the start of the chain
184 * \param buf buffer holding the certificate data in PEM or DER format
185 * \param buflen size of the buffer
186 * (including the terminating null byte for PEM data)
188 * \return 0 if all certificates parsed successfully, a positive number
189 * if partly successful or a specific X509 or PEM error code
191 int mbedtls_x509_crt_parse( mbedtls_x509_crt *chain, const unsigned char *buf, size_t buflen );
193 #if defined(MBEDTLS_FS_IO)
195 * \brief Load one or more certificates and add them
196 * to the chained list. Parses permissively. If some
197 * certificates can be parsed, the result is the number
198 * of failed certificates it encountered. If none complete
199 * correctly, the first error is returned.
201 * \param chain points to the start of the chain
202 * \param path filename to read the certificates from
204 * \return 0 if all certificates parsed successfully, a positive number
205 * if partly successful or a specific X509 or PEM error code
207 int mbedtls_x509_crt_parse_file( mbedtls_x509_crt *chain, const char *path );
210 * \brief Load one or more certificate files from a path and add them
211 * to the chained list. Parses permissively. If some
212 * certificates can be parsed, the result is the number
213 * of failed certificates it encountered. If none complete
214 * correctly, the first error is returned.
216 * \param chain points to the start of the chain
217 * \param path directory / folder to read the certificate files from
219 * \return 0 if all certificates parsed successfully, a positive number
220 * if partly successful or a specific X509 or PEM error code
222 int mbedtls_x509_crt_parse_path( mbedtls_x509_crt *chain, const char *path );
223 #endif /* MBEDTLS_FS_IO */
226 * \brief Returns an informational string about the
229 * \param buf Buffer to write to
230 * \param size Maximum size of buffer
231 * \param prefix A line prefix
232 * \param crt The X509 certificate to represent
234 * \return The length of the string written (not including the
235 * terminated nul byte), or a negative error code.
237 int mbedtls_x509_crt_info( char *buf, size_t size, const char *prefix,
238 const mbedtls_x509_crt *crt );
241 * \brief Returns an informational string about the
242 * verification status of a certificate.
244 * \param buf Buffer to write to
245 * \param size Maximum size of buffer
246 * \param prefix A line prefix
247 * \param flags Verification flags created by mbedtls_x509_crt_verify()
249 * \return The length of the string written (not including the
250 * terminated nul byte), or a negative error code.
252 int mbedtls_x509_crt_verify_info( char *buf, size_t size, const char *prefix,
256 * \brief Verify the certificate signature
258 * The verify callback is a user-supplied callback that
259 * can clear / modify / add flags for a certificate. If set,
260 * the verification callback is called for each
261 * certificate in the chain (from the trust-ca down to the
262 * presented crt). The parameters for the callback are:
263 * (void *parameter, mbedtls_x509_crt *crt, int certificate_depth,
264 * int *flags). With the flags representing current flags for
265 * that specific certificate and the certificate depth from
266 * the bottom (Peer cert depth = 0).
268 * All flags left after returning from the callback
269 * are also returned to the application. The function should
270 * return 0 for anything but a fatal error.
272 * \note In case verification failed, the results can be displayed
273 * using \c mbedtls_x509_crt_verify_info()
275 * \note Same as \c mbedtls_x509_crt_verify_with_profile() with the
276 * default security profile.
278 * \note It is your responsibility to provide up-to-date CRLs for
279 * all trusted CAs. If no CRL is provided for the CA that was
280 * used to sign the certificate, CRL verification is skipped
281 * silently, that is *without* setting any flag.
283 * \param crt a certificate (chain) to be verified
284 * \param trust_ca the list of trusted CAs
285 * \param ca_crl the list of CRLs for trusted CAs (see note above)
286 * \param cn expected Common Name (can be set to
287 * NULL if the CN must not be verified)
288 * \param flags result of the verification
289 * \param f_vrfy verification function
290 * \param p_vrfy verification parameter
292 * \return 0 if successful or MBEDTLS_ERR_X509_CERT_VERIFY_FAILED
293 * in which case *flags will have one or more
294 * MBEDTLS_X509_BADCERT_XXX or MBEDTLS_X509_BADCRL_XXX flags
296 * or another error in case of a fatal error encountered
297 * during the verification process.
299 int mbedtls_x509_crt_verify( mbedtls_x509_crt *crt,
300 mbedtls_x509_crt *trust_ca,
301 mbedtls_x509_crl *ca_crl,
302 const char *cn, uint32_t *flags,
303 int (*f_vrfy)(void *, mbedtls_x509_crt *, int, uint32_t *),
307 * \brief Verify the certificate signature according to profile
309 * \note Same as \c mbedtls_x509_crt_verify(), but with explicit
312 * \note The restrictions on keys (RSA minimum size, allowed curves
313 * for ECDSA) apply to all certificates: trusted root,
314 * intermediate CAs if any, and end entity certificate.
316 * \param crt a certificate (chain) to be verified
317 * \param trust_ca the list of trusted CAs
318 * \param ca_crl the list of CRLs for trusted CAs
319 * \param profile security profile for verification
320 * \param cn expected Common Name (can be set to
321 * NULL if the CN must not be verified)
322 * \param flags result of the verification
323 * \param f_vrfy verification function
324 * \param p_vrfy verification parameter
326 * \return 0 if successful or MBEDTLS_ERR_X509_CERT_VERIFY_FAILED
327 * in which case *flags will have one or more
328 * MBEDTLS_X509_BADCERT_XXX or MBEDTLS_X509_BADCRL_XXX flags
330 * or another error in case of a fatal error encountered
331 * during the verification process.
333 int mbedtls_x509_crt_verify_with_profile( mbedtls_x509_crt *crt,
334 mbedtls_x509_crt *trust_ca,
335 mbedtls_x509_crl *ca_crl,
336 const mbedtls_x509_crt_profile *profile,
337 const char *cn, uint32_t *flags,
338 int (*f_vrfy)(void *, mbedtls_x509_crt *, int, uint32_t *),
341 #if defined(MBEDTLS_X509_CHECK_KEY_USAGE)
343 * \brief Check usage of certificate against keyUsage extension.
345 * \param crt Leaf certificate used.
346 * \param usage Intended usage(s) (eg MBEDTLS_X509_KU_KEY_ENCIPHERMENT
347 * before using the certificate to perform an RSA key
350 * \note Except for decipherOnly and encipherOnly, a bit set in the
351 * usage argument means this bit MUST be set in the
352 * certificate. For decipherOnly and encipherOnly, it means
353 * that bit MAY be set.
355 * \return 0 is these uses of the certificate are allowed,
356 * MBEDTLS_ERR_X509_BAD_INPUT_DATA if the keyUsage extension
357 * is present but does not match the usage argument.
359 * \note You should only call this function on leaf certificates, on
360 * (intermediate) CAs the keyUsage extension is automatically
361 * checked by \c mbedtls_x509_crt_verify().
363 int mbedtls_x509_crt_check_key_usage( const mbedtls_x509_crt *crt,
364 unsigned int usage );
365 #endif /* MBEDTLS_X509_CHECK_KEY_USAGE) */
367 #if defined(MBEDTLS_X509_CHECK_EXTENDED_KEY_USAGE)
369 * \brief Check usage of certificate against extentedJeyUsage.
371 * \param crt Leaf certificate used.
372 * \param usage_oid Intended usage (eg MBEDTLS_OID_SERVER_AUTH or MBEDTLS_OID_CLIENT_AUTH).
373 * \param usage_len Length of usage_oid (eg given by MBEDTLS_OID_SIZE()).
375 * \return 0 if this use of the certificate is allowed,
376 * MBEDTLS_ERR_X509_BAD_INPUT_DATA if not.
378 * \note Usually only makes sense on leaf certificates.
380 int mbedtls_x509_crt_check_extended_key_usage( const mbedtls_x509_crt *crt,
381 const char *usage_oid,
383 #endif /* MBEDTLS_X509_CHECK_EXTENDED_KEY_USAGE) */
385 #if defined(MBEDTLS_X509_CRL_PARSE_C)
387 * \brief Verify the certificate revocation status
389 * \param crt a certificate to be verified
390 * \param crl the CRL to verify against
392 * \return 1 if the certificate is revoked, 0 otherwise
395 int mbedtls_x509_crt_is_revoked( const mbedtls_x509_crt *crt, const mbedtls_x509_crl *crl );
396 #endif /* MBEDTLS_X509_CRL_PARSE_C */
399 * \brief Initialize a certificate (chain)
401 * \param crt Certificate chain to initialize
403 void mbedtls_x509_crt_init( mbedtls_x509_crt *crt );
406 * \brief Unallocate all certificate data
408 * \param crt Certificate chain to free
410 void mbedtls_x509_crt_free( mbedtls_x509_crt *crt );
411 #endif /* MBEDTLS_X509_CRT_PARSE_C */
414 /* \} addtogroup x509_module */
416 #if defined(MBEDTLS_X509_CRT_WRITE_C)
418 * \brief Initialize a CRT writing context
420 * \param ctx CRT context to initialize
422 void mbedtls_x509write_crt_init( mbedtls_x509write_cert *ctx );
425 * \brief Set the verion for a Certificate
426 * Default: MBEDTLS_X509_CRT_VERSION_3
428 * \param ctx CRT context to use
429 * \param version version to set (MBEDTLS_X509_CRT_VERSION_1, MBEDTLS_X509_CRT_VERSION_2 or
430 * MBEDTLS_X509_CRT_VERSION_3)
432 void mbedtls_x509write_crt_set_version( mbedtls_x509write_cert *ctx, int version );
435 * \brief Set the serial number for a Certificate.
437 * \param ctx CRT context to use
438 * \param serial serial number to set
440 * \return 0 if successful
442 int mbedtls_x509write_crt_set_serial( mbedtls_x509write_cert *ctx, const mbedtls_mpi *serial );
445 * \brief Set the validity period for a Certificate
446 * Timestamps should be in string format for UTC timezone
447 * i.e. "YYYYMMDDhhmmss"
448 * e.g. "20131231235959" for December 31st 2013
451 * \param ctx CRT context to use
452 * \param not_before not_before timestamp
453 * \param not_after not_after timestamp
455 * \return 0 if timestamp was parsed successfully, or
456 * a specific error code
458 int mbedtls_x509write_crt_set_validity( mbedtls_x509write_cert *ctx, const char *not_before,
459 const char *not_after );
462 * \brief Set the issuer name for a Certificate
463 * Issuer names should contain a comma-separated list
464 * of OID types and values:
465 * e.g. "C=UK,O=ARM,CN=mbed TLS CA"
467 * \param ctx CRT context to use
468 * \param issuer_name issuer name to set
470 * \return 0 if issuer name was parsed successfully, or
471 * a specific error code
473 int mbedtls_x509write_crt_set_issuer_name( mbedtls_x509write_cert *ctx,
474 const char *issuer_name );
477 * \brief Set the subject name for a Certificate
478 * Subject names should contain a comma-separated list
479 * of OID types and values:
480 * e.g. "C=UK,O=ARM,CN=mbed TLS Server 1"
482 * \param ctx CRT context to use
483 * \param subject_name subject name to set
485 * \return 0 if subject name was parsed successfully, or
486 * a specific error code
488 int mbedtls_x509write_crt_set_subject_name( mbedtls_x509write_cert *ctx,
489 const char *subject_name );
492 * \brief Set the subject public key for the certificate
494 * \param ctx CRT context to use
495 * \param key public key to include
497 void mbedtls_x509write_crt_set_subject_key( mbedtls_x509write_cert *ctx, mbedtls_pk_context *key );
500 * \brief Set the issuer key used for signing the certificate
502 * \param ctx CRT context to use
503 * \param key private key to sign with
505 void mbedtls_x509write_crt_set_issuer_key( mbedtls_x509write_cert *ctx, mbedtls_pk_context *key );
508 * \brief Set the MD algorithm to use for the signature
509 * (e.g. MBEDTLS_MD_SHA1)
511 * \param ctx CRT context to use
512 * \param md_alg MD algorithm to use
514 void mbedtls_x509write_crt_set_md_alg( mbedtls_x509write_cert *ctx, mbedtls_md_type_t md_alg );
517 * \brief Generic function to add to or replace an extension in the
520 * \param ctx CRT context to use
521 * \param oid OID of the extension
522 * \param oid_len length of the OID
523 * \param critical if the extension is critical (per the RFC's definition)
524 * \param val value of the extension OCTET STRING
525 * \param val_len length of the value data
527 * \return 0 if successful, or a MBEDTLS_ERR_X509_ALLOC_FAILED
529 int mbedtls_x509write_crt_set_extension( mbedtls_x509write_cert *ctx,
530 const char *oid, size_t oid_len,
532 const unsigned char *val, size_t val_len );
535 * \brief Set the basicConstraints extension for a CRT
537 * \param ctx CRT context to use
538 * \param is_ca is this a CA certificate
539 * \param max_pathlen maximum length of certificate chains below this
540 * certificate (only for CA certificates, -1 is
543 * \return 0 if successful, or a MBEDTLS_ERR_X509_ALLOC_FAILED
545 int mbedtls_x509write_crt_set_basic_constraints( mbedtls_x509write_cert *ctx,
546 int is_ca, int max_pathlen );
548 #if defined(MBEDTLS_SHA1_C)
550 * \brief Set the subjectKeyIdentifier extension for a CRT
551 * Requires that mbedtls_x509write_crt_set_subject_key() has been
554 * \param ctx CRT context to use
556 * \return 0 if successful, or a MBEDTLS_ERR_X509_ALLOC_FAILED
558 int mbedtls_x509write_crt_set_subject_key_identifier( mbedtls_x509write_cert *ctx );
561 * \brief Set the authorityKeyIdentifier extension for a CRT
562 * Requires that mbedtls_x509write_crt_set_issuer_key() has been
565 * \param ctx CRT context to use
567 * \return 0 if successful, or a MBEDTLS_ERR_X509_ALLOC_FAILED
569 int mbedtls_x509write_crt_set_authority_key_identifier( mbedtls_x509write_cert *ctx );
570 #endif /* MBEDTLS_SHA1_C */
573 * \brief Set the Key Usage Extension flags
574 * (e.g. MBEDTLS_X509_KU_DIGITAL_SIGNATURE | MBEDTLS_X509_KU_KEY_CERT_SIGN)
576 * \param ctx CRT context to use
577 * \param key_usage key usage flags to set
579 * \return 0 if successful, or MBEDTLS_ERR_X509_ALLOC_FAILED
581 int mbedtls_x509write_crt_set_key_usage( mbedtls_x509write_cert *ctx,
582 unsigned int key_usage );
585 * \brief Set the Netscape Cert Type flags
586 * (e.g. MBEDTLS_X509_NS_CERT_TYPE_SSL_CLIENT | MBEDTLS_X509_NS_CERT_TYPE_EMAIL)
588 * \param ctx CRT context to use
589 * \param ns_cert_type Netscape Cert Type flags to set
591 * \return 0 if successful, or MBEDTLS_ERR_X509_ALLOC_FAILED
593 int mbedtls_x509write_crt_set_ns_cert_type( mbedtls_x509write_cert *ctx,
594 unsigned char ns_cert_type );
597 * \brief Free the contents of a CRT write context
599 * \param ctx CRT context to free
601 void mbedtls_x509write_crt_free( mbedtls_x509write_cert *ctx );
604 * \brief Write a built up certificate to a X509 DER structure
605 * Note: data is written at the end of the buffer! Use the
606 * return value to determine where you should start
609 * \param ctx certificate to write away
610 * \param buf buffer to write to
611 * \param size size of the buffer
612 * \param f_rng RNG function (for signature, see note)
613 * \param p_rng RNG parameter
615 * \return length of data written if successful, or a specific
618 * \note f_rng may be NULL if RSA is used for signature and the
619 * signature is made offline (otherwise f_rng is desirable
620 * for countermeasures against timing attacks).
621 * ECDSA signatures always require a non-NULL f_rng.
623 int mbedtls_x509write_crt_der( mbedtls_x509write_cert *ctx, unsigned char *buf, size_t size,
624 int (*f_rng)(void *, unsigned char *, size_t),
627 #if defined(MBEDTLS_PEM_WRITE_C)
629 * \brief Write a built up certificate to a X509 PEM string
631 * \param ctx certificate to write away
632 * \param buf buffer to write to
633 * \param size size of the buffer
634 * \param f_rng RNG function (for signature, see note)
635 * \param p_rng RNG parameter
637 * \return 0 if successful, or a specific error code
639 * \note f_rng may be NULL if RSA is used for signature and the
640 * signature is made offline (otherwise f_rng is desirable
641 * for countermeasures against timing attacks).
642 * ECDSA signatures always require a non-NULL f_rng.
644 int mbedtls_x509write_crt_pem( mbedtls_x509write_cert *ctx, unsigned char *buf, size_t size,
645 int (*f_rng)(void *, unsigned char *, size_t),
647 #endif /* MBEDTLS_PEM_WRITE_C */
648 #endif /* MBEDTLS_X509_CRT_WRITE_C */
654 #endif /* mbedtls_x509_crt.h */