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 #ifndef MBEDTLS_X509_CRT_H
11 #define MBEDTLS_X509_CRT_H
12 #include "mbedtls/private_access.h"
13 
14 #include "mbedtls/build_info.h"
15 
16 #include "mbedtls/x509.h"
17 #include "mbedtls/x509_crl.h"
18 #include "mbedtls/bignum.h"
19 
20 /**
21  * \addtogroup x509_module
22  * \{
23  */
24 
25 #ifdef __cplusplus
26 extern "C" {
27 #endif
28 
29 /**
30  * \name Structures and functions for parsing and writing X.509 certificates
31  * \{
32  */
33 
34 /**
35  * Container for an X.509 certificate. The certificate may be chained.
36  *
37  * Some fields of this structure are publicly readable. Do not modify
38  * them except via Mbed TLS library functions: the effect of modifying
39  * those fields or the data that those fields points to is unspecified.
40  */
41 typedef struct mbedtls_x509_crt {
42     int MBEDTLS_PRIVATE(own_buffer);                     /**< Indicates if \c raw is owned
43                                                           *   by the structure or not.        */
44     mbedtls_x509_buf raw;               /**< The raw certificate data (DER). */
45     mbedtls_x509_buf tbs;               /**< The raw certificate body (DER). The part that is To Be Signed. */
46 
47     int version;                /**< The X.509 version. (1=v1, 2=v2, 3=v3) */
48     mbedtls_x509_buf serial;            /**< Unique id for certificate issued by a specific CA. */
49     mbedtls_x509_buf sig_oid;           /**< Signature algorithm, e.g. sha1RSA */
50 
51     mbedtls_x509_buf issuer_raw;        /**< The raw issuer data (DER). Used for quick comparison. */
52     mbedtls_x509_buf subject_raw;       /**< The raw subject data (DER). Used for quick comparison. */
53 
54     mbedtls_x509_name issuer;           /**< The parsed issuer data (named information object). */
55     mbedtls_x509_name subject;          /**< The parsed subject data (named information object). */
56 
57     mbedtls_x509_time valid_from;       /**< Start time of certificate validity. */
58     mbedtls_x509_time valid_to;         /**< End time of certificate validity. */
59 
60     mbedtls_x509_buf pk_raw;
61     mbedtls_pk_context pk;              /**< Container for the public key context. */
62 
63     mbedtls_x509_buf issuer_id;         /**< Optional X.509 v2/v3 issuer unique identifier. */
64     mbedtls_x509_buf subject_id;        /**< Optional X.509 v2/v3 subject unique identifier. */
65     mbedtls_x509_buf v3_ext;            /**< Optional X.509 v3 extensions.  */
66     mbedtls_x509_sequence subject_alt_names; /**< Optional list of raw entries of Subject Alternative Names extension. These can be later parsed by mbedtls_x509_parse_subject_alt_name. */
67     mbedtls_x509_buf subject_key_id;    /**< Optional X.509 v3 extension subject key identifier. */
68     mbedtls_x509_authority authority_key_id;    /**< Optional X.509 v3 extension authority key identifier. */
69 
70     mbedtls_x509_sequence certificate_policies; /**< Optional list of certificate policies (Only anyPolicy is printed and enforced, however the rest of the policies are still listed). */
71 
72     int MBEDTLS_PRIVATE(ext_types);              /**< Bit string containing detected and parsed extensions */
73     int MBEDTLS_PRIVATE(ca_istrue);              /**< Optional Basic Constraint extension value: 1 if this certificate belongs to a CA, 0 otherwise. */
74     int MBEDTLS_PRIVATE(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+ */
75 
76     unsigned int MBEDTLS_PRIVATE(key_usage);     /**< Optional key usage extension value: See the values in x509.h */
77 
78     mbedtls_x509_sequence ext_key_usage; /**< Optional list of extended key usage OIDs. */
79 
80     unsigned char MBEDTLS_PRIVATE(ns_cert_type); /**< Optional Netscape certificate type extension value: See the values in x509.h */
81 
82     mbedtls_x509_buf MBEDTLS_PRIVATE(sig);               /**< Signature: hash of the tbs part signed with the private key. */
83     mbedtls_md_type_t MBEDTLS_PRIVATE(sig_md);           /**< Internal representation of the MD algorithm of the signature algorithm, e.g. MBEDTLS_MD_SHA256 */
84     mbedtls_pk_type_t MBEDTLS_PRIVATE(sig_pk);           /**< Internal representation of the Public Key algorithm of the signature algorithm, e.g. MBEDTLS_PK_RSA */
85     void *MBEDTLS_PRIVATE(sig_opts);             /**< Signature options to be passed to mbedtls_pk_verify_ext(), e.g. for RSASSA-PSS */
86 
87     /** Next certificate in the linked list that constitutes the CA chain.
88      * \p NULL indicates the end of the list.
89      * Do not modify this field directly. */
90     struct mbedtls_x509_crt *next;
91 }
92 mbedtls_x509_crt;
93 
94 /**
95  * Build flag from an algorithm/curve identifier (pk, md, ecp)
96  * Since 0 is always XXX_NONE, ignore it.
97  */
98 #define MBEDTLS_X509_ID_FLAG(id)   (1 << ((id) - 1))
99 
100 /**
101  * Security profile for certificate verification.
102  *
103  * All lists are bitfields, built by ORing flags from MBEDTLS_X509_ID_FLAG().
104  *
105  * The fields of this structure are part of the public API and can be
106  * manipulated directly by applications. Future versions of the library may
107  * add extra fields or reorder existing fields.
108  *
109  * You can create custom profiles by starting from a copy of
110  * an existing profile, such as mbedtls_x509_crt_profile_default or
111  * mbedtls_x509_ctr_profile_none and then tune it to your needs.
112  *
113  * For example to allow SHA-224 in addition to the default:
114  *
115  *  mbedtls_x509_crt_profile my_profile = mbedtls_x509_crt_profile_default;
116  *  my_profile.allowed_mds |= MBEDTLS_X509_ID_FLAG( MBEDTLS_MD_SHA224 );
117  *
118  * Or to allow only RSA-3072+ with SHA-256:
119  *
120  *  mbedtls_x509_crt_profile my_profile = mbedtls_x509_crt_profile_none;
121  *  my_profile.allowed_mds = MBEDTLS_X509_ID_FLAG( MBEDTLS_MD_SHA256 );
122  *  my_profile.allowed_pks = MBEDTLS_X509_ID_FLAG( MBEDTLS_PK_RSA );
123  *  my_profile.rsa_min_bitlen = 3072;
124  */
125 typedef struct mbedtls_x509_crt_profile {
126     uint32_t allowed_mds;       /**< MDs for signatures         */
127     uint32_t allowed_pks;       /**< PK algs for public keys;
128                                  *   this applies to all certificates
129                                  *   in the provided chain.     */
130     uint32_t allowed_curves;    /**< Elliptic curves for ECDSA  */
131     uint32_t rsa_min_bitlen;    /**< Minimum size for RSA keys  */
132 }
133 mbedtls_x509_crt_profile;
134 
135 #define MBEDTLS_X509_CRT_VERSION_1              0
136 #define MBEDTLS_X509_CRT_VERSION_2              1
137 #define MBEDTLS_X509_CRT_VERSION_3              2
138 
139 #define MBEDTLS_X509_RFC5280_MAX_SERIAL_LEN 20
140 #define MBEDTLS_X509_RFC5280_UTC_TIME_LEN   15
141 
142 #if !defined(MBEDTLS_X509_MAX_FILE_PATH_LEN)
143 #define MBEDTLS_X509_MAX_FILE_PATH_LEN 512
144 #endif
145 
146 /* This macro unfolds to the concatenation of macro invocations
147  * X509_CRT_ERROR_INFO( error code,
148  *                             error code as string,
149  *                             human readable description )
150  * where X509_CRT_ERROR_INFO is defined by the user.
151  * See x509_crt.c for an example of how to use this. */
152 #define MBEDTLS_X509_CRT_ERROR_INFO_LIST                                  \
153     X509_CRT_ERROR_INFO(MBEDTLS_X509_BADCERT_EXPIRED,            \
154                         "MBEDTLS_X509_BADCERT_EXPIRED",          \
155                         "The certificate validity has expired") \
156     X509_CRT_ERROR_INFO(MBEDTLS_X509_BADCERT_REVOKED,            \
157                         "MBEDTLS_X509_BADCERT_REVOKED",          \
158                         "The certificate has been revoked (is on a CRL)") \
159     X509_CRT_ERROR_INFO(MBEDTLS_X509_BADCERT_CN_MISMATCH,                  \
160                         "MBEDTLS_X509_BADCERT_CN_MISMATCH",                \
161                         "The certificate Common Name (CN) does not match with the expected CN") \
162     X509_CRT_ERROR_INFO(MBEDTLS_X509_BADCERT_NOT_TRUSTED,                             \
163                         "MBEDTLS_X509_BADCERT_NOT_TRUSTED",                           \
164                         "The certificate is not correctly signed by the trusted CA") \
165     X509_CRT_ERROR_INFO(MBEDTLS_X509_BADCRL_NOT_TRUSTED,                      \
166                         "MBEDTLS_X509_BADCRL_NOT_TRUSTED",                    \
167                         "The CRL is not correctly signed by the trusted CA") \
168     X509_CRT_ERROR_INFO(MBEDTLS_X509_BADCRL_EXPIRED,    \
169                         "MBEDTLS_X509_BADCRL_EXPIRED",  \
170                         "The CRL is expired")          \
171     X509_CRT_ERROR_INFO(MBEDTLS_X509_BADCERT_MISSING,   \
172                         "MBEDTLS_X509_BADCERT_MISSING", \
173                         "Certificate was missing")     \
174     X509_CRT_ERROR_INFO(MBEDTLS_X509_BADCERT_SKIP_VERIFY,         \
175                         "MBEDTLS_X509_BADCERT_SKIP_VERIFY",       \
176                         "Certificate verification was skipped")  \
177     X509_CRT_ERROR_INFO(MBEDTLS_X509_BADCERT_OTHER,                          \
178                         "MBEDTLS_X509_BADCERT_OTHER",                        \
179                         "Other reason (can be used by verify callback)")    \
180     X509_CRT_ERROR_INFO(MBEDTLS_X509_BADCERT_FUTURE,                         \
181                         "MBEDTLS_X509_BADCERT_FUTURE",                       \
182                         "The certificate validity starts in the future")    \
183     X509_CRT_ERROR_INFO(MBEDTLS_X509_BADCRL_FUTURE,     \
184                         "MBEDTLS_X509_BADCRL_FUTURE",   \
185                         "The CRL is from the future")  \
186     X509_CRT_ERROR_INFO(MBEDTLS_X509_BADCERT_KEY_USAGE,                      \
187                         "MBEDTLS_X509_BADCERT_KEY_USAGE",                    \
188                         "Usage does not match the keyUsage extension")      \
189     X509_CRT_ERROR_INFO(MBEDTLS_X509_BADCERT_EXT_KEY_USAGE,                       \
190                         "MBEDTLS_X509_BADCERT_EXT_KEY_USAGE",                     \
191                         "Usage does not match the extendedKeyUsage extension")   \
192     X509_CRT_ERROR_INFO(MBEDTLS_X509_BADCERT_NS_CERT_TYPE,                        \
193                         "MBEDTLS_X509_BADCERT_NS_CERT_TYPE",                      \
194                         "Usage does not match the nsCertType extension")         \
195     X509_CRT_ERROR_INFO(MBEDTLS_X509_BADCERT_BAD_MD,                              \
196                         "MBEDTLS_X509_BADCERT_BAD_MD",                            \
197                         "The certificate is signed with an unacceptable hash.")  \
198     X509_CRT_ERROR_INFO(MBEDTLS_X509_BADCERT_BAD_PK,                                                  \
199                         "MBEDTLS_X509_BADCERT_BAD_PK",                                                \
200                         "The certificate is signed with an unacceptable PK alg (eg RSA vs ECDSA).")  \
201     X509_CRT_ERROR_INFO(MBEDTLS_X509_BADCERT_BAD_KEY,                                                            \
202                         "MBEDTLS_X509_BADCERT_BAD_KEY",                                                          \
203                         "The certificate is signed with an unacceptable key (eg bad curve, RSA too short).")    \
204     X509_CRT_ERROR_INFO(MBEDTLS_X509_BADCRL_BAD_MD,                          \
205                         "MBEDTLS_X509_BADCRL_BAD_MD",                        \
206                         "The CRL is signed with an unacceptable hash.")     \
207     X509_CRT_ERROR_INFO(MBEDTLS_X509_BADCRL_BAD_PK,                                            \
208                         "MBEDTLS_X509_BADCRL_BAD_PK",                                          \
209                         "The CRL is signed with an unacceptable PK alg (eg RSA vs ECDSA).")   \
210     X509_CRT_ERROR_INFO(MBEDTLS_X509_BADCRL_BAD_KEY,                                                    \
211                         "MBEDTLS_X509_BADCRL_BAD_KEY",                                                  \
212                         "The CRL is signed with an unacceptable key (eg bad curve, RSA too short).")
213 
214 /**
215  * Container for writing a certificate (CRT)
216  */
217 typedef struct mbedtls_x509write_cert {
218     int MBEDTLS_PRIVATE(version);
219     unsigned char MBEDTLS_PRIVATE(serial)[MBEDTLS_X509_RFC5280_MAX_SERIAL_LEN];
220     size_t MBEDTLS_PRIVATE(serial_len);
221     mbedtls_pk_context *MBEDTLS_PRIVATE(subject_key);
222     mbedtls_pk_context *MBEDTLS_PRIVATE(issuer_key);
223     mbedtls_asn1_named_data *MBEDTLS_PRIVATE(subject);
224     mbedtls_asn1_named_data *MBEDTLS_PRIVATE(issuer);
225     mbedtls_md_type_t MBEDTLS_PRIVATE(md_alg);
226     char MBEDTLS_PRIVATE(not_before)[MBEDTLS_X509_RFC5280_UTC_TIME_LEN + 1];
227     char MBEDTLS_PRIVATE(not_after)[MBEDTLS_X509_RFC5280_UTC_TIME_LEN + 1];
228     mbedtls_asn1_named_data *MBEDTLS_PRIVATE(extensions);
229 }
230 mbedtls_x509write_cert;
231 
232 /**
233  * \brief           Set Subject Alternative Name
234  *
235  * \param ctx       Certificate context to use
236  * \param san_list  List of SAN values
237  *
238  * \return          0 if successful, or MBEDTLS_ERR_X509_ALLOC_FAILED
239  *
240  * \note            "dnsName", "uniformResourceIdentifier", "IP address",
241  *                  "otherName", and "DirectoryName", as defined in RFC 5280,
242  *                  are supported.
243  */
244 int mbedtls_x509write_crt_set_subject_alternative_name(mbedtls_x509write_cert *ctx,
245                                                        const mbedtls_x509_san_list *san_list);
246 
247 /**
248  * Item in a verification chain: cert and flags for it
249  */
250 typedef struct {
251     mbedtls_x509_crt *MBEDTLS_PRIVATE(crt);
252     uint32_t MBEDTLS_PRIVATE(flags);
253 } mbedtls_x509_crt_verify_chain_item;
254 
255 /**
256  * Max size of verification chain: end-entity + intermediates + trusted root
257  */
258 #define MBEDTLS_X509_MAX_VERIFY_CHAIN_SIZE  (MBEDTLS_X509_MAX_INTERMEDIATE_CA + 2)
259 
260 /**
261  * Verification chain as built by \c mbedtls_crt_verify_chain()
262  */
263 typedef struct {
264     mbedtls_x509_crt_verify_chain_item MBEDTLS_PRIVATE(items)[MBEDTLS_X509_MAX_VERIFY_CHAIN_SIZE];
265     unsigned MBEDTLS_PRIVATE(len);
266 
267 #if defined(MBEDTLS_X509_TRUSTED_CERTIFICATE_CALLBACK)
268     /* This stores the list of potential trusted signers obtained from
269      * the CA callback used for the CRT verification, if configured.
270      * We must track it somewhere because the callback passes its
271      * ownership to the caller. */
272     mbedtls_x509_crt *MBEDTLS_PRIVATE(trust_ca_cb_result);
273 #endif /* MBEDTLS_X509_TRUSTED_CERTIFICATE_CALLBACK */
274 } mbedtls_x509_crt_verify_chain;
275 
276 #if defined(MBEDTLS_ECDSA_C) && defined(MBEDTLS_ECP_RESTARTABLE)
277 
278 /**
279  * \brief       Context for resuming X.509 verify operations
280  */
281 typedef struct {
282     /* for check_signature() */
283     mbedtls_pk_restart_ctx MBEDTLS_PRIVATE(pk);
284 
285     /* for find_parent_in() */
286     mbedtls_x509_crt *MBEDTLS_PRIVATE(parent); /* non-null iff parent_in in progress */
287     mbedtls_x509_crt *MBEDTLS_PRIVATE(fallback_parent);
288     int MBEDTLS_PRIVATE(fallback_signature_is_good);
289 
290     /* for find_parent() */
291     int MBEDTLS_PRIVATE(parent_is_trusted); /* -1 if find_parent is not in progress */
292 
293     /* for verify_chain() */
294     enum {
295         x509_crt_rs_none,
296         x509_crt_rs_find_parent,
297     } MBEDTLS_PRIVATE(in_progress);  /* none if no operation is in progress */
298     int MBEDTLS_PRIVATE(self_cnt);
299     mbedtls_x509_crt_verify_chain MBEDTLS_PRIVATE(ver_chain);
300 
301 } mbedtls_x509_crt_restart_ctx;
302 
303 #else /* MBEDTLS_ECDSA_C && MBEDTLS_ECP_RESTARTABLE */
304 
305 /* Now we can declare functions that take a pointer to that */
306 typedef void mbedtls_x509_crt_restart_ctx;
307 
308 #endif /* MBEDTLS_ECDSA_C && MBEDTLS_ECP_RESTARTABLE */
309 
310 #if defined(MBEDTLS_X509_CRT_PARSE_C)
311 /**
312  * Default security profile. Should provide a good balance between security
313  * and compatibility with current deployments.
314  *
315  * This profile permits:
316  * - SHA2 hashes with at least 256 bits: SHA-256, SHA-384, SHA-512.
317  * - Elliptic curves with 255 bits and above except secp256k1.
318  * - RSA with 2048 bits and above.
319  *
320  * New minor versions of Mbed TLS may extend this profile, for example if
321  * new algorithms are added to the library. New minor versions of Mbed TLS will
322  * not reduce this profile unless serious security concerns require it.
323  */
324 extern const mbedtls_x509_crt_profile mbedtls_x509_crt_profile_default;
325 
326 /**
327  * Expected next default profile. Recommended for new deployments.
328  * Currently targets a 128-bit security level, except for allowing RSA-2048.
329  * This profile may change at any time.
330  */
331 extern const mbedtls_x509_crt_profile mbedtls_x509_crt_profile_next;
332 
333 /**
334  * NSA Suite B profile.
335  */
336 extern const mbedtls_x509_crt_profile mbedtls_x509_crt_profile_suiteb;
337 
338 /**
339  * Empty profile that allows nothing. Useful as a basis for constructing
340  * custom profiles.
341  */
342 extern const mbedtls_x509_crt_profile mbedtls_x509_crt_profile_none;
343 
344 /**
345  * \brief          Parse a single DER formatted certificate and add it
346  *                 to the end of the provided chained list.
347  *
348  * \note           If #MBEDTLS_USE_PSA_CRYPTO is enabled, the PSA crypto
349  *                 subsystem must have been initialized by calling
350  *                 psa_crypto_init() before calling this function.
351  *
352  * \param chain    The pointer to the start of the CRT chain to attach to.
353  *                 When parsing the first CRT in a chain, this should point
354  *                 to an instance of ::mbedtls_x509_crt initialized through
355  *                 mbedtls_x509_crt_init().
356  * \param buf      The buffer holding the DER encoded certificate.
357  * \param buflen   The size in Bytes of \p buf.
358  *
359  * \note           This function makes an internal copy of the CRT buffer
360  *                 \p buf. In particular, \p buf may be destroyed or reused
361  *                 after this call returns. To avoid duplicating the CRT
362  *                 buffer (at the cost of stricter lifetime constraints),
363  *                 use mbedtls_x509_crt_parse_der_nocopy() instead.
364  *
365  * \return         \c 0 if successful.
366  * \return         A negative error code on failure.
367  */
368 int mbedtls_x509_crt_parse_der(mbedtls_x509_crt *chain,
369                                const unsigned char *buf,
370                                size_t buflen);
371 
372 /**
373  * \brief          The type of certificate extension callbacks.
374  *
375  *                 Callbacks of this type are passed to and used by the
376  *                 mbedtls_x509_crt_parse_der_with_ext_cb() routine when
377  *                 it encounters either an unsupported extension or a
378  *                 "certificate policies" extension containing any
379  *                 unsupported certificate policies.
380  *                 Future versions of the library may invoke the callback
381  *                 in other cases, if and when the need arises.
382  *
383  * \param p_ctx    An opaque context passed to the callback.
384  * \param crt      The certificate being parsed.
385  * \param oid      The OID of the extension.
386  * \param critical Whether the extension is critical.
387  * \param p        Pointer to the start of the extension value
388  *                 (the content of the OCTET STRING).
389  * \param end      End of extension value.
390  *
391  * \note           The callback must fail and return a negative error code
392  *                 if it can not parse or does not support the extension.
393  *                 When the callback fails to parse a critical extension
394  *                 mbedtls_x509_crt_parse_der_with_ext_cb() also fails.
395  *                 When the callback fails to parse a non critical extension
396  *                 mbedtls_x509_crt_parse_der_with_ext_cb() simply skips
397  *                 the extension and continues parsing.
398  *
399  * \return         \c 0 on success.
400  * \return         A negative error code on failure.
401  */
402 typedef int (*mbedtls_x509_crt_ext_cb_t)(void *p_ctx,
403                                          mbedtls_x509_crt const *crt,
404                                          mbedtls_x509_buf const *oid,
405                                          int critical,
406                                          const unsigned char *p,
407                                          const unsigned char *end);
408 
409 /**
410  * \brief            Parse a single DER formatted certificate and add it
411  *                   to the end of the provided chained list.
412  *
413  * \note             If #MBEDTLS_USE_PSA_CRYPTO is enabled, the PSA crypto
414  *                   subsystem must have been initialized by calling
415  *                   psa_crypto_init() before calling this function.
416  *
417  * \param chain      The pointer to the start of the CRT chain to attach to.
418  *                   When parsing the first CRT in a chain, this should point
419  *                   to an instance of ::mbedtls_x509_crt initialized through
420  *                   mbedtls_x509_crt_init().
421  * \param buf        The buffer holding the DER encoded certificate.
422  * \param buflen     The size in Bytes of \p buf.
423  * \param make_copy  When not zero this function makes an internal copy of the
424  *                   CRT buffer \p buf. In particular, \p buf may be destroyed
425  *                   or reused after this call returns.
426  *                   When zero this function avoids duplicating the CRT buffer
427  *                   by taking temporary ownership thereof until the CRT
428  *                   is destroyed (like mbedtls_x509_crt_parse_der_nocopy())
429  * \param cb         A callback invoked for every unsupported certificate
430  *                   extension.
431  * \param p_ctx      An opaque context passed to the callback.
432  *
433  * \note             This call is functionally equivalent to
434  *                   mbedtls_x509_crt_parse_der(), and/or
435  *                   mbedtls_x509_crt_parse_der_nocopy()
436  *                   but it calls the callback with every unsupported
437  *                   certificate extension and additionally the
438  *                   "certificate policies" extension if it contains any
439  *                   unsupported certificate policies.
440  *                   The callback must return a negative error code if it
441  *                   does not know how to handle such an extension.
442  *                   When the callback fails to parse a critical extension
443  *                   mbedtls_x509_crt_parse_der_with_ext_cb() also fails.
444  *                   When the callback fails to parse a non critical extension
445  *                   mbedtls_x509_crt_parse_der_with_ext_cb() simply skips
446  *                   the extension and continues parsing.
447  *                   Future versions of the library may invoke the callback
448  *                   in other cases, if and when the need arises.
449  *
450  * \return           \c 0 if successful.
451  * \return           A negative error code on failure.
452  */
453 int mbedtls_x509_crt_parse_der_with_ext_cb(mbedtls_x509_crt *chain,
454                                            const unsigned char *buf,
455                                            size_t buflen,
456                                            int make_copy,
457                                            mbedtls_x509_crt_ext_cb_t cb,
458                                            void *p_ctx);
459 
460 /**
461  * \brief          Parse a single DER formatted certificate and add it
462  *                 to the end of the provided chained list. This is a
463  *                 variant of mbedtls_x509_crt_parse_der() which takes
464  *                 temporary ownership of the CRT buffer until the CRT
465  *                 is destroyed.
466  *
467  * \note           If #MBEDTLS_USE_PSA_CRYPTO is enabled, the PSA crypto
468  *                 subsystem must have been initialized by calling
469  *                 psa_crypto_init() before calling this function.
470  *
471  * \param chain    The pointer to the start of the CRT chain to attach to.
472  *                 When parsing the first CRT in a chain, this should point
473  *                 to an instance of ::mbedtls_x509_crt initialized through
474  *                 mbedtls_x509_crt_init().
475  * \param buf      The address of the readable buffer holding the DER encoded
476  *                 certificate to use. On success, this buffer must be
477  *                 retained and not be changed for the lifetime of the
478  *                 CRT chain \p chain, that is, until \p chain is destroyed
479  *                 through a call to mbedtls_x509_crt_free().
480  * \param buflen   The size in Bytes of \p buf.
481  *
482  * \note           This call is functionally equivalent to
483  *                 mbedtls_x509_crt_parse_der(), but it avoids creating a
484  *                 copy of the input buffer at the cost of stronger lifetime
485  *                 constraints. This is useful in constrained environments
486  *                 where duplication of the CRT cannot be tolerated.
487  *
488  * \return         \c 0 if successful.
489  * \return         A negative error code on failure.
490  */
491 int mbedtls_x509_crt_parse_der_nocopy(mbedtls_x509_crt *chain,
492                                       const unsigned char *buf,
493                                       size_t buflen);
494 
495 /**
496  * \brief          Parse one DER-encoded or one or more concatenated PEM-encoded
497  *                 certificates and add them to the chained list.
498  *
499  *                 For CRTs in PEM encoding, the function parses permissively:
500  *                 if at least one certificate can be parsed, the function
501  *                 returns the number of certificates for which parsing failed
502  *                 (hence \c 0 if all certificates were parsed successfully).
503  *                 If no certificate could be parsed, the function returns
504  *                 the first (negative) error encountered during parsing.
505  *
506  *                 PEM encoded certificates may be interleaved by other data
507  *                 such as human readable descriptions of their content, as
508  *                 long as the certificates are enclosed in the PEM specific
509  *                 '-----{BEGIN/END} CERTIFICATE-----' delimiters.
510  *
511  * \note           If #MBEDTLS_USE_PSA_CRYPTO is enabled, the PSA crypto
512  *                 subsystem must have been initialized by calling
513  *                 psa_crypto_init() before calling this function.
514  *
515  * \param chain    The chain to which to add the parsed certificates.
516  * \param buf      The buffer holding the certificate data in PEM or DER format.
517  *                 For certificates in PEM encoding, this may be a concatenation
518  *                 of multiple certificates; for DER encoding, the buffer must
519  *                 comprise exactly one certificate.
520  * \param buflen   The size of \p buf, including the terminating \c NULL byte
521  *                 in case of PEM encoded data.
522  *
523  * \return         \c 0 if all certificates were parsed successfully.
524  * \return         The (positive) number of certificates that couldn't
525  *                 be parsed if parsing was partly successful (see above).
526  * \return         A negative X509 or PEM error code otherwise.
527  *
528  */
529 int mbedtls_x509_crt_parse(mbedtls_x509_crt *chain, const unsigned char *buf, size_t buflen);
530 
531 #if defined(MBEDTLS_FS_IO)
532 /**
533  * \brief          Load one or more certificates and add them
534  *                 to the chained list. Parses permissively. If some
535  *                 certificates can be parsed, the result is the number
536  *                 of failed certificates it encountered. If none complete
537  *                 correctly, the first error is returned.
538  *
539  * \note           If #MBEDTLS_USE_PSA_CRYPTO is enabled, the PSA crypto
540  *                 subsystem must have been initialized by calling
541  *                 psa_crypto_init() before calling this function.
542  *
543  * \param chain    points to the start of the chain
544  * \param path     filename to read the certificates from
545  *
546  * \return         0 if all certificates parsed successfully, a positive number
547  *                 if partly successful or a specific X509 or PEM error code
548  */
549 int mbedtls_x509_crt_parse_file(mbedtls_x509_crt *chain, const char *path);
550 
551 /**
552  * \brief          Load one or more certificate files from a path and add them
553  *                 to the chained list. Parses permissively. If some
554  *                 certificates can be parsed, the result is the number
555  *                 of failed certificates it encountered. If none complete
556  *                 correctly, the first error is returned.
557  *
558  * \param chain    points to the start of the chain
559  * \param path     directory / folder to read the certificate files from
560  *
561  * \return         0 if all certificates parsed successfully, a positive number
562  *                 if partly successful or a specific X509 or PEM error code
563  */
564 int mbedtls_x509_crt_parse_path(mbedtls_x509_crt *chain, const char *path);
565 
566 #endif /* MBEDTLS_FS_IO */
567 
568 #if !defined(MBEDTLS_X509_REMOVE_INFO)
569 /**
570  * \brief          Returns an informational string about the
571  *                 certificate.
572  *
573  * \param buf      Buffer to write to
574  * \param size     Maximum size of buffer
575  * \param prefix   A line prefix
576  * \param crt      The X509 certificate to represent
577  *
578  * \return         The length of the string written (not including the
579  *                 terminated nul byte), or a negative error code.
580  */
581 int mbedtls_x509_crt_info(char *buf, size_t size, const char *prefix,
582                           const mbedtls_x509_crt *crt);
583 
584 /**
585  * \brief          Returns an informational string about the
586  *                 verification status of a certificate.
587  *
588  * \param buf      Buffer to write to
589  * \param size     Maximum size of buffer
590  * \param prefix   A line prefix
591  * \param flags    Verification flags created by mbedtls_x509_crt_verify()
592  *
593  * \return         The length of the string written (not including the
594  *                 terminated nul byte), or a negative error code.
595  */
596 int mbedtls_x509_crt_verify_info(char *buf, size_t size, const char *prefix,
597                                  uint32_t flags);
598 #endif /* !MBEDTLS_X509_REMOVE_INFO */
599 
600 /**
601  * \brief          Verify a chain of certificates.
602  *
603  *                 The verify callback is a user-supplied callback that
604  *                 can clear / modify / add flags for a certificate. If set,
605  *                 the verification callback is called for each
606  *                 certificate in the chain (from the trust-ca down to the
607  *                 presented crt). The parameters for the callback are:
608  *                 (void *parameter, mbedtls_x509_crt *crt, int certificate_depth,
609  *                 int *flags). With the flags representing current flags for
610  *                 that specific certificate and the certificate depth from
611  *                 the bottom (Peer cert depth = 0).
612  *
613  *                 All flags left after returning from the callback
614  *                 are also returned to the application. The function should
615  *                 return 0 for anything (including invalid certificates)
616  *                 other than fatal error, as a non-zero return code
617  *                 immediately aborts the verification process. For fatal
618  *                 errors, a specific error code should be used (different
619  *                 from MBEDTLS_ERR_X509_CERT_VERIFY_FAILED which should not
620  *                 be returned at this point), or MBEDTLS_ERR_X509_FATAL_ERROR
621  *                 can be used if no better code is available.
622  *
623  * \note           In case verification failed, the results can be displayed
624  *                 using \c mbedtls_x509_crt_verify_info()
625  *
626  * \note           Same as \c mbedtls_x509_crt_verify_with_profile() with the
627  *                 default security profile.
628  *
629  * \note           It is your responsibility to provide up-to-date CRLs for
630  *                 all trusted CAs. If no CRL is provided for the CA that was
631  *                 used to sign the certificate, CRL verification is skipped
632  *                 silently, that is *without* setting any flag.
633  *
634  * \note           The \c trust_ca list can contain two types of certificates:
635  *                 (1) those of trusted root CAs, so that certificates
636  *                 chaining up to those CAs will be trusted, and (2)
637  *                 self-signed end-entity certificates to be trusted (for
638  *                 specific peers you know) - in that case, the self-signed
639  *                 certificate doesn't need to have the CA bit set.
640  *
641  * \param crt      The certificate chain to be verified.
642  * \param trust_ca The list of trusted CAs.
643  * \param ca_crl   The list of CRLs for trusted CAs.
644  * \param cn       The expected Common Name. This will be checked to be
645  *                 present in the certificate's subjectAltNames extension or,
646  *                 if this extension is absent, as a CN component in its
647  *                 Subject name. DNS names and IP addresses are fully
648  *                 supported, while the URI subtype is partially supported:
649  *                 only exact matching, without any normalization procedures
650  *                 described in 7.4 of RFC5280, will result in a positive
651  *                 URI verification.
652  *                 This may be \c NULL if the CN need not be verified.
653  * \param flags    The address at which to store the result of the verification.
654  *                 If the verification couldn't be completed, the flag value is
655  *                 set to (uint32_t) -1.
656  * \param f_vrfy   The verification callback to use. See the documentation
657  *                 of mbedtls_x509_crt_verify() for more information.
658  * \param p_vrfy   The context to be passed to \p f_vrfy.
659  *
660  * \return         \c 0 if the chain is valid with respect to the
661  *                 passed CN, CAs, CRLs and security profile.
662  * \return         #MBEDTLS_ERR_X509_CERT_VERIFY_FAILED in case the
663  *                 certificate chain verification failed. In this case,
664  *                 \c *flags will have one or more
665  *                 \c MBEDTLS_X509_BADCERT_XXX or \c MBEDTLS_X509_BADCRL_XXX
666  *                 flags set.
667  * \return         Another negative error code in case of a fatal error
668  *                 encountered during the verification process.
669  */
670 int mbedtls_x509_crt_verify(mbedtls_x509_crt *crt,
671                             mbedtls_x509_crt *trust_ca,
672                             mbedtls_x509_crl *ca_crl,
673                             const char *cn, uint32_t *flags,
674                             int (*f_vrfy)(void *, mbedtls_x509_crt *, int, uint32_t *),
675                             void *p_vrfy);
676 
677 /**
678  * \brief          Verify a chain of certificates with respect to
679  *                 a configurable security profile.
680  *
681  * \note           Same as \c mbedtls_x509_crt_verify(), but with explicit
682  *                 security profile.
683  *
684  * \note           The restrictions on keys (RSA minimum size, allowed curves
685  *                 for ECDSA) apply to all certificates: trusted root,
686  *                 intermediate CAs if any, and end entity certificate.
687  *
688  * \param crt      The certificate chain to be verified.
689  * \param trust_ca The list of trusted CAs.
690  * \param ca_crl   The list of CRLs for trusted CAs.
691  * \param profile  The security profile to use for the verification.
692  * \param cn       The expected Common Name. This may be \c NULL if the
693  *                 CN need not be verified.
694  * \param flags    The address at which to store the result of the verification.
695  *                 If the verification couldn't be completed, the flag value is
696  *                 set to (uint32_t) -1.
697  * \param f_vrfy   The verification callback to use. See the documentation
698  *                 of mbedtls_x509_crt_verify() for more information.
699  * \param p_vrfy   The context to be passed to \p f_vrfy.
700  *
701  * \return         \c 0 if the chain is valid with respect to the
702  *                 passed CN, CAs, CRLs and security profile.
703  * \return         #MBEDTLS_ERR_X509_CERT_VERIFY_FAILED in case the
704  *                 certificate chain verification failed. In this case,
705  *                 \c *flags will have one or more
706  *                 \c MBEDTLS_X509_BADCERT_XXX or \c MBEDTLS_X509_BADCRL_XXX
707  *                 flags set.
708  * \return         Another negative error code in case of a fatal error
709  *                 encountered during the verification process.
710  */
711 int mbedtls_x509_crt_verify_with_profile(mbedtls_x509_crt *crt,
712                                          mbedtls_x509_crt *trust_ca,
713                                          mbedtls_x509_crl *ca_crl,
714                                          const mbedtls_x509_crt_profile *profile,
715                                          const char *cn, uint32_t *flags,
716                                          int (*f_vrfy)(void *, mbedtls_x509_crt *, int, uint32_t *),
717                                          void *p_vrfy);
718 
719 /**
720  * \brief          Restartable version of \c mbedtls_crt_verify_with_profile()
721  *
722  * \note           Performs the same job as \c mbedtls_crt_verify_with_profile()
723  *                 but can return early and restart according to the limit
724  *                 set with \c mbedtls_ecp_set_max_ops() to reduce blocking.
725  *
726  * \param crt      The certificate chain to be verified.
727  * \param trust_ca The list of trusted CAs.
728  * \param ca_crl   The list of CRLs for trusted CAs.
729  * \param profile  The security profile to use for the verification.
730  * \param cn       The expected Common Name. This may be \c NULL if the
731  *                 CN need not be verified.
732  * \param flags    The address at which to store the result of the verification.
733  *                 If the verification couldn't be completed, the flag value is
734  *                 set to (uint32_t) -1.
735  * \param f_vrfy   The verification callback to use. See the documentation
736  *                 of mbedtls_x509_crt_verify() for more information.
737  * \param p_vrfy   The context to be passed to \p f_vrfy.
738  * \param rs_ctx   The restart context to use. This may be set to \c NULL
739  *                 to disable restartable ECC.
740  *
741  * \return         See \c mbedtls_crt_verify_with_profile(), or
742  * \return         #MBEDTLS_ERR_ECP_IN_PROGRESS if maximum number of
743  *                 operations was reached: see \c mbedtls_ecp_set_max_ops().
744  */
745 int mbedtls_x509_crt_verify_restartable(mbedtls_x509_crt *crt,
746                                         mbedtls_x509_crt *trust_ca,
747                                         mbedtls_x509_crl *ca_crl,
748                                         const mbedtls_x509_crt_profile *profile,
749                                         const char *cn, uint32_t *flags,
750                                         int (*f_vrfy)(void *, mbedtls_x509_crt *, int, uint32_t *),
751                                         void *p_vrfy,
752                                         mbedtls_x509_crt_restart_ctx *rs_ctx);
753 
754 /**
755  * \brief               The type of trusted certificate callbacks.
756  *
757  *                      Callbacks of this type are passed to and used by the CRT
758  *                      verification routine mbedtls_x509_crt_verify_with_ca_cb()
759  *                      when looking for trusted signers of a given certificate.
760  *
761  *                      On success, the callback returns a list of trusted
762  *                      certificates to be considered as potential signers
763  *                      for the input certificate.
764  *
765  * \param p_ctx         An opaque context passed to the callback.
766  * \param child         The certificate for which to search a potential signer.
767  *                      This will point to a readable certificate.
768  * \param candidate_cas The address at which to store the address of the first
769  *                      entry in the generated linked list of candidate signers.
770  *                      This will not be \c NULL.
771  *
772  * \note                The callback must only return a non-zero value on a
773  *                      fatal error. If, in contrast, the search for a potential
774  *                      signer completes without a single candidate, the
775  *                      callback must return \c 0 and set \c *candidate_cas
776  *                      to \c NULL.
777  *
778  * \return              \c 0 on success. In this case, \c *candidate_cas points
779  *                      to a heap-allocated linked list of instances of
780  *                      ::mbedtls_x509_crt, and ownership of this list is passed
781  *                      to the caller.
782  * \return              A negative error code on failure.
783  */
784 typedef int (*mbedtls_x509_crt_ca_cb_t)(void *p_ctx,
785                                         mbedtls_x509_crt const *child,
786                                         mbedtls_x509_crt **candidate_cas);
787 
788 #if defined(MBEDTLS_X509_TRUSTED_CERTIFICATE_CALLBACK)
789 /**
790  * \brief          Version of \c mbedtls_x509_crt_verify_with_profile() which
791  *                 uses a callback to acquire the list of trusted CA
792  *                 certificates.
793  *
794  * \param crt      The certificate chain to be verified.
795  * \param f_ca_cb  The callback to be used to query for potential signers
796  *                 of a given child certificate. See the documentation of
797  *                 ::mbedtls_x509_crt_ca_cb_t for more information.
798  * \param p_ca_cb  The opaque context to be passed to \p f_ca_cb.
799  * \param profile  The security profile for the verification.
800  * \param cn       The expected Common Name. This may be \c NULL if the
801  *                 CN need not be verified.
802  * \param flags    The address at which to store the result of the verification.
803  *                 If the verification couldn't be completed, the flag value is
804  *                 set to (uint32_t) -1.
805  * \param f_vrfy   The verification callback to use. See the documentation
806  *                 of mbedtls_x509_crt_verify() for more information.
807  * \param p_vrfy   The context to be passed to \p f_vrfy.
808  *
809  * \return         See \c mbedtls_crt_verify_with_profile().
810  */
811 int mbedtls_x509_crt_verify_with_ca_cb(mbedtls_x509_crt *crt,
812                                        mbedtls_x509_crt_ca_cb_t f_ca_cb,
813                                        void *p_ca_cb,
814                                        const mbedtls_x509_crt_profile *profile,
815                                        const char *cn, uint32_t *flags,
816                                        int (*f_vrfy)(void *, mbedtls_x509_crt *, int, uint32_t *),
817                                        void *p_vrfy);
818 
819 #endif /* MBEDTLS_X509_TRUSTED_CERTIFICATE_CALLBACK */
820 
821 /**
822  * \brief          Check usage of certificate against keyUsage extension.
823  *
824  * \param crt      Leaf certificate used.
825  * \param usage    Intended usage(s) (eg MBEDTLS_X509_KU_KEY_ENCIPHERMENT
826  *                 before using the certificate to perform an RSA key
827  *                 exchange).
828  *
829  * \note           Except for decipherOnly and encipherOnly, a bit set in the
830  *                 usage argument means this bit MUST be set in the
831  *                 certificate. For decipherOnly and encipherOnly, it means
832  *                 that bit MAY be set.
833  *
834  * \return         0 is these uses of the certificate are allowed,
835  *                 MBEDTLS_ERR_X509_BAD_INPUT_DATA if the keyUsage extension
836  *                 is present but does not match the usage argument.
837  *
838  * \note           You should only call this function on leaf certificates, on
839  *                 (intermediate) CAs the keyUsage extension is automatically
840  *                 checked by \c mbedtls_x509_crt_verify().
841  */
842 int mbedtls_x509_crt_check_key_usage(const mbedtls_x509_crt *crt,
843                                      unsigned int usage);
844 
845 /**
846  * \brief           Check usage of certificate against extendedKeyUsage.
847  *
848  * \param crt       Leaf certificate used.
849  * \param usage_oid Intended usage (eg MBEDTLS_OID_SERVER_AUTH or
850  *                  MBEDTLS_OID_CLIENT_AUTH).
851  * \param usage_len Length of usage_oid (eg given by MBEDTLS_OID_SIZE()).
852  *
853  * \return          0 if this use of the certificate is allowed,
854  *                  MBEDTLS_ERR_X509_BAD_INPUT_DATA if not.
855  *
856  * \note            Usually only makes sense on leaf certificates.
857  */
858 int mbedtls_x509_crt_check_extended_key_usage(const mbedtls_x509_crt *crt,
859                                               const char *usage_oid,
860                                               size_t usage_len);
861 
862 #if defined(MBEDTLS_X509_CRL_PARSE_C)
863 /**
864  * \brief          Verify the certificate revocation status
865  *
866  * \param crt      a certificate to be verified
867  * \param crl      the CRL to verify against
868  *
869  * \return         1 if the certificate is revoked, 0 otherwise
870  *
871  */
872 int mbedtls_x509_crt_is_revoked(const mbedtls_x509_crt *crt, const mbedtls_x509_crl *crl);
873 #endif /* MBEDTLS_X509_CRL_PARSE_C */
874 
875 /**
876  * \brief          Initialize a certificate (chain)
877  *
878  * \param crt      Certificate chain to initialize
879  */
880 void mbedtls_x509_crt_init(mbedtls_x509_crt *crt);
881 
882 /**
883  * \brief          Unallocate all certificate data
884  *
885  * \param crt      Certificate chain to free
886  */
887 void mbedtls_x509_crt_free(mbedtls_x509_crt *crt);
888 
889 #if defined(MBEDTLS_ECDSA_C) && defined(MBEDTLS_ECP_RESTARTABLE)
890 /**
891  * \brief           Initialize a restart context
892  */
893 void mbedtls_x509_crt_restart_init(mbedtls_x509_crt_restart_ctx *ctx);
894 
895 /**
896  * \brief           Free the components of a restart context
897  */
898 void mbedtls_x509_crt_restart_free(mbedtls_x509_crt_restart_ctx *ctx);
899 #endif /* MBEDTLS_ECDSA_C && MBEDTLS_ECP_RESTARTABLE */
900 #endif /* MBEDTLS_X509_CRT_PARSE_C */
901 
902 /**
903  * \brief               Query certificate for given extension type
904  *
905  * \param[in] ctx       Certificate context to be queried, must not be \c NULL
906  * \param ext_type      Extension type being queried for, must be a valid
907  *                      extension type. Must be one of the MBEDTLS_X509_EXT_XXX
908  *                      values
909  *
910  * \return              0 if the given extension type is not present,
911  *                      non-zero otherwise
912  */
mbedtls_x509_crt_has_ext_type(const mbedtls_x509_crt * ctx,int ext_type)913 static inline int mbedtls_x509_crt_has_ext_type(const mbedtls_x509_crt *ctx,
914                                                 int ext_type)
915 {
916     return ctx->MBEDTLS_PRIVATE(ext_types) & ext_type;
917 }
918 
919 /** \} name Structures and functions for parsing and writing X.509 certificates */
920 
921 #if defined(MBEDTLS_X509_CRT_WRITE_C)
922 /**
923  * \brief           Initialize a CRT writing context
924  *
925  * \param ctx       CRT context to initialize
926  */
927 void mbedtls_x509write_crt_init(mbedtls_x509write_cert *ctx);
928 
929 /**
930  * \brief           Set the version for a Certificate
931  *                  Default: MBEDTLS_X509_CRT_VERSION_3
932  *
933  * \param ctx       CRT context to use
934  * \param version   version to set (MBEDTLS_X509_CRT_VERSION_1, MBEDTLS_X509_CRT_VERSION_2 or
935  *                                  MBEDTLS_X509_CRT_VERSION_3)
936  */
937 void mbedtls_x509write_crt_set_version(mbedtls_x509write_cert *ctx, int version);
938 
939 #if defined(MBEDTLS_BIGNUM_C) && !defined(MBEDTLS_DEPRECATED_REMOVED)
940 /**
941  * \brief           Set the serial number for a Certificate.
942  *
943  * \deprecated      This function is deprecated and will be removed in a
944  *                  future version of the library. Please use
945  *                  mbedtls_x509write_crt_set_serial_raw() instead.
946  *
947  * \note            Even though the MBEDTLS_BIGNUM_C guard looks redundant since
948  *                  X509 depends on PK and PK depends on BIGNUM, this emphasizes
949  *                  a direct dependency between X509 and BIGNUM which is going
950  *                  to be deprecated in the future.
951  *
952  * \param ctx       CRT context to use
953  * \param serial    serial number to set
954  *
955  * \return          0 if successful
956  */
957 int MBEDTLS_DEPRECATED mbedtls_x509write_crt_set_serial(
958     mbedtls_x509write_cert *ctx, const mbedtls_mpi *serial);
959 #endif // MBEDTLS_BIGNUM_C && !MBEDTLS_DEPRECATED_REMOVED
960 
961 /**
962  * \brief           Set the serial number for a Certificate.
963  *
964  * \param ctx          CRT context to use
965  * \param serial       A raw array of bytes containing the serial number in big
966  *                     endian format
967  * \param serial_len   Length of valid bytes (expressed in bytes) in \p serial
968  *                     input buffer
969  *
970  * \return          0 if successful, or
971  *                  MBEDTLS_ERR_X509_BAD_INPUT_DATA if the provided input buffer
972  *                  is too big (longer than MBEDTLS_X509_RFC5280_MAX_SERIAL_LEN)
973  */
974 int mbedtls_x509write_crt_set_serial_raw(mbedtls_x509write_cert *ctx,
975                                          unsigned char *serial, size_t serial_len);
976 
977 /**
978  * \brief           Set the validity period for a Certificate
979  *                  Timestamps should be in string format for UTC timezone
980  *                  i.e. "YYYYMMDDhhmmss"
981  *                  e.g. "20131231235959" for December 31st 2013
982  *                       at 23:59:59
983  *
984  * \param ctx       CRT context to use
985  * \param not_before    not_before timestamp
986  * \param not_after     not_after timestamp
987  *
988  * \return          0 if timestamp was parsed successfully, or
989  *                  a specific error code
990  */
991 int mbedtls_x509write_crt_set_validity(mbedtls_x509write_cert *ctx, const char *not_before,
992                                        const char *not_after);
993 
994 /**
995  * \brief           Set the issuer name for a Certificate
996  *                  Issuer names should contain a comma-separated list
997  *                  of OID types and values:
998  *                  e.g. "C=UK,O=ARM,CN=Mbed TLS CA"
999  *
1000  * \param ctx           CRT context to use
1001  * \param issuer_name   issuer name to set
1002  *
1003  * \return          0 if issuer name was parsed successfully, or
1004  *                  a specific error code
1005  */
1006 int mbedtls_x509write_crt_set_issuer_name(mbedtls_x509write_cert *ctx,
1007                                           const char *issuer_name);
1008 
1009 /**
1010  * \brief           Set the subject name for a Certificate
1011  *                  Subject names should contain a comma-separated list
1012  *                  of OID types and values:
1013  *                  e.g. "C=UK,O=ARM,CN=Mbed TLS Server 1"
1014  *
1015  * \param ctx           CRT context to use
1016  * \param subject_name  subject name to set
1017  *
1018  * \return          0 if subject name was parsed successfully, or
1019  *                  a specific error code
1020  */
1021 int mbedtls_x509write_crt_set_subject_name(mbedtls_x509write_cert *ctx,
1022                                            const char *subject_name);
1023 
1024 /**
1025  * \brief           Set the subject public key for the certificate
1026  *
1027  * \param ctx       CRT context to use
1028  * \param key       public key to include
1029  */
1030 void mbedtls_x509write_crt_set_subject_key(mbedtls_x509write_cert *ctx, mbedtls_pk_context *key);
1031 
1032 /**
1033  * \brief           Set the issuer key used for signing the certificate
1034  *
1035  * \param ctx       CRT context to use
1036  * \param key       private key to sign with
1037  */
1038 void mbedtls_x509write_crt_set_issuer_key(mbedtls_x509write_cert *ctx, mbedtls_pk_context *key);
1039 
1040 /**
1041  * \brief           Set the MD algorithm to use for the signature
1042  *                  (e.g. MBEDTLS_MD_SHA1)
1043  *
1044  * \param ctx       CRT context to use
1045  * \param md_alg    MD algorithm to use
1046  */
1047 void mbedtls_x509write_crt_set_md_alg(mbedtls_x509write_cert *ctx, mbedtls_md_type_t md_alg);
1048 
1049 /**
1050  * \brief           Generic function to add to or replace an extension in the
1051  *                  CRT
1052  *
1053  * \param ctx       CRT context to use
1054  * \param oid       OID of the extension
1055  * \param oid_len   length of the OID
1056  * \param critical  if the extension is critical (per the RFC's definition)
1057  * \param val       value of the extension OCTET STRING
1058  * \param val_len   length of the value data
1059  *
1060  * \return          0 if successful, or a MBEDTLS_ERR_X509_ALLOC_FAILED
1061  */
1062 int mbedtls_x509write_crt_set_extension(mbedtls_x509write_cert *ctx,
1063                                         const char *oid, size_t oid_len,
1064                                         int critical,
1065                                         const unsigned char *val, size_t val_len);
1066 
1067 /**
1068  * \brief           Set the basicConstraints extension for a CRT
1069  *
1070  * \param ctx       CRT context to use
1071  * \param is_ca     is this a CA certificate
1072  * \param max_pathlen   maximum length of certificate chains below this
1073  *                      certificate (only for CA certificates, -1 is
1074  *                      unlimited)
1075  *
1076  * \return          0 if successful, or a MBEDTLS_ERR_X509_ALLOC_FAILED
1077  */
1078 int mbedtls_x509write_crt_set_basic_constraints(mbedtls_x509write_cert *ctx,
1079                                                 int is_ca, int max_pathlen);
1080 
1081 #if defined(MBEDTLS_MD_CAN_SHA1)
1082 /**
1083  * \brief           Set the subjectKeyIdentifier extension for a CRT
1084  *                  Requires that mbedtls_x509write_crt_set_subject_key() has been
1085  *                  called before
1086  *
1087  * \param ctx       CRT context to use
1088  *
1089  * \return          0 if successful, or a MBEDTLS_ERR_X509_ALLOC_FAILED
1090  */
1091 int mbedtls_x509write_crt_set_subject_key_identifier(mbedtls_x509write_cert *ctx);
1092 
1093 /**
1094  * \brief           Set the authorityKeyIdentifier extension for a CRT
1095  *                  Requires that mbedtls_x509write_crt_set_issuer_key() has been
1096  *                  called before
1097  *
1098  * \param ctx       CRT context to use
1099  *
1100  * \return          0 if successful, or a MBEDTLS_ERR_X509_ALLOC_FAILED
1101  */
1102 int mbedtls_x509write_crt_set_authority_key_identifier(mbedtls_x509write_cert *ctx);
1103 #endif /* MBEDTLS_MD_CAN_SHA1 */
1104 
1105 /**
1106  * \brief           Set the Key Usage Extension flags
1107  *                  (e.g. MBEDTLS_X509_KU_DIGITAL_SIGNATURE | MBEDTLS_X509_KU_KEY_CERT_SIGN)
1108  *
1109  * \param ctx       CRT context to use
1110  * \param key_usage key usage flags to set
1111  *
1112  * \return          0 if successful, or MBEDTLS_ERR_X509_ALLOC_FAILED
1113  */
1114 int mbedtls_x509write_crt_set_key_usage(mbedtls_x509write_cert *ctx,
1115                                         unsigned int key_usage);
1116 
1117 /**
1118  * \brief           Set the Extended Key Usage Extension
1119  *                  (e.g. MBEDTLS_OID_SERVER_AUTH)
1120  *
1121  * \param ctx       CRT context to use
1122  * \param exts      extended key usage extensions to set, a sequence of
1123  *                  MBEDTLS_ASN1_OID objects
1124  *
1125  * \return          0 if successful, or MBEDTLS_ERR_X509_ALLOC_FAILED
1126  */
1127 int mbedtls_x509write_crt_set_ext_key_usage(mbedtls_x509write_cert *ctx,
1128                                             const mbedtls_asn1_sequence *exts);
1129 
1130 /**
1131  * \brief           Set the Netscape Cert Type flags
1132  *                  (e.g. MBEDTLS_X509_NS_CERT_TYPE_SSL_CLIENT | MBEDTLS_X509_NS_CERT_TYPE_EMAIL)
1133  *
1134  * \param ctx           CRT context to use
1135  * \param ns_cert_type  Netscape Cert Type flags to set
1136  *
1137  * \return          0 if successful, or MBEDTLS_ERR_X509_ALLOC_FAILED
1138  */
1139 int mbedtls_x509write_crt_set_ns_cert_type(mbedtls_x509write_cert *ctx,
1140                                            unsigned char ns_cert_type);
1141 
1142 /**
1143  * \brief           Free the contents of a CRT write context
1144  *
1145  * \param ctx       CRT context to free
1146  */
1147 void mbedtls_x509write_crt_free(mbedtls_x509write_cert *ctx);
1148 
1149 /**
1150  * \brief           Write a built up certificate to a X509 DER structure
1151  *                  Note: data is written at the end of the buffer! Use the
1152  *                        return value to determine where you should start
1153  *                        using the buffer
1154  *
1155  * \param ctx       certificate to write away
1156  * \param buf       buffer to write to
1157  * \param size      size of the buffer
1158  * \param f_rng     RNG function. This must not be \c NULL.
1159  * \param p_rng     RNG parameter
1160  *
1161  * \return          length of data written if successful, or a specific
1162  *                  error code
1163  *
1164  * \note            \p f_rng is used for the signature operation.
1165  */
1166 int mbedtls_x509write_crt_der(mbedtls_x509write_cert *ctx, unsigned char *buf, size_t size,
1167                               int (*f_rng)(void *, unsigned char *, size_t),
1168                               void *p_rng);
1169 
1170 #if defined(MBEDTLS_PEM_WRITE_C)
1171 /**
1172  * \brief           Write a built up certificate to a X509 PEM string
1173  *
1174  * \param ctx       certificate to write away
1175  * \param buf       buffer to write to
1176  * \param size      size of the buffer
1177  * \param f_rng     RNG function. This must not be \c NULL.
1178  * \param p_rng     RNG parameter
1179  *
1180  * \return          0 if successful, or a specific error code
1181  *
1182  * \note            \p f_rng is used for the signature operation.
1183  */
1184 int mbedtls_x509write_crt_pem(mbedtls_x509write_cert *ctx, unsigned char *buf, size_t size,
1185                               int (*f_rng)(void *, unsigned char *, size_t),
1186                               void *p_rng);
1187 #endif /* MBEDTLS_PEM_WRITE_C */
1188 #endif /* MBEDTLS_X509_CRT_WRITE_C */
1189 
1190 /** \} addtogroup x509_module */
1191 
1192 #ifdef __cplusplus
1193 }
1194 #endif
1195 
1196 #endif /* mbedtls_x509_crt.h */
1197