1 /**
2 * \file x509.h
3 *
4 * \brief X.509 generic defines and structures
5 */
6 /*
7 * Copyright The Mbed TLS Contributors
8 * SPDX-License-Identifier: Apache-2.0
9 *
10 * Licensed under the Apache License, Version 2.0 (the "License"); you may
11 * not use this file except in compliance with the License.
12 * You may obtain a copy of the License at
13 *
14 * http://www.apache.org/licenses/LICENSE-2.0
15 *
16 * Unless required by applicable law or agreed to in writing, software
17 * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
18 * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
19 * See the License for the specific language governing permissions and
20 * limitations under the License.
21 */
22 #ifndef MBEDTLS_X509_H
23 #define MBEDTLS_X509_H
24 #include "mbedtls/private_access.h"
25
26 #include "mbedtls/build_info.h"
27
28 #include "mbedtls/asn1.h"
29 #include "mbedtls/pk.h"
30
31 #if defined(MBEDTLS_RSA_C)
32 #include "mbedtls/rsa.h"
33 #endif
34
35 /**
36 * \addtogroup x509_module
37 * \{
38 */
39
40 #if !defined(MBEDTLS_X509_MAX_INTERMEDIATE_CA)
41 /**
42 * Maximum number of intermediate CAs in a verification chain.
43 * That is, maximum length of the chain, excluding the end-entity certificate
44 * and the trusted root certificate.
45 *
46 * Set this to a low value to prevent an adversary from making you waste
47 * resources verifying an overlong certificate chain.
48 */
49 #define MBEDTLS_X509_MAX_INTERMEDIATE_CA 8
50 #endif
51
52 /**
53 * \name X509 Error codes
54 * \{
55 */
56 /** Unavailable feature, e.g. RSA hashing/encryption combination. */
57 #define MBEDTLS_ERR_X509_FEATURE_UNAVAILABLE -0x2080
58 /** Requested OID is unknown. */
59 #define MBEDTLS_ERR_X509_UNKNOWN_OID -0x2100
60 /** The CRT/CRL/CSR format is invalid, e.g. different type expected. */
61 #define MBEDTLS_ERR_X509_INVALID_FORMAT -0x2180
62 /** The CRT/CRL/CSR version element is invalid. */
63 #define MBEDTLS_ERR_X509_INVALID_VERSION -0x2200
64 /** The serial tag or value is invalid. */
65 #define MBEDTLS_ERR_X509_INVALID_SERIAL -0x2280
66 /** The algorithm tag or value is invalid. */
67 #define MBEDTLS_ERR_X509_INVALID_ALG -0x2300
68 /** The name tag or value is invalid. */
69 #define MBEDTLS_ERR_X509_INVALID_NAME -0x2380
70 /** The date tag or value is invalid. */
71 #define MBEDTLS_ERR_X509_INVALID_DATE -0x2400
72 /** The signature tag or value invalid. */
73 #define MBEDTLS_ERR_X509_INVALID_SIGNATURE -0x2480
74 /** The extension tag or value is invalid. */
75 #define MBEDTLS_ERR_X509_INVALID_EXTENSIONS -0x2500
76 /** CRT/CRL/CSR has an unsupported version number. */
77 #define MBEDTLS_ERR_X509_UNKNOWN_VERSION -0x2580
78 /** Signature algorithm (oid) is unsupported. */
79 #define MBEDTLS_ERR_X509_UNKNOWN_SIG_ALG -0x2600
80 /** Signature algorithms do not match. (see \c ::mbedtls_x509_crt sig_oid) */
81 #define MBEDTLS_ERR_X509_SIG_MISMATCH -0x2680
82 /** Certificate verification failed, e.g. CRL, CA or signature check failed. */
83 #define MBEDTLS_ERR_X509_CERT_VERIFY_FAILED -0x2700
84 /** Format not recognized as DER or PEM. */
85 #define MBEDTLS_ERR_X509_CERT_UNKNOWN_FORMAT -0x2780
86 /** Input invalid. */
87 #define MBEDTLS_ERR_X509_BAD_INPUT_DATA -0x2800
88 /** Allocation of memory failed. */
89 #define MBEDTLS_ERR_X509_ALLOC_FAILED -0x2880
90 /** Read/write of file failed. */
91 #define MBEDTLS_ERR_X509_FILE_IO_ERROR -0x2900
92 /** Destination buffer is too small. */
93 #define MBEDTLS_ERR_X509_BUFFER_TOO_SMALL -0x2980
94 /** A fatal error occurred, eg the chain is too long or the vrfy callback failed. */
95 #define MBEDTLS_ERR_X509_FATAL_ERROR -0x3000
96 /** \} name X509 Error codes */
97
98 /**
99 * \name X509 Verify codes
100 * \{
101 */
102 /* Reminder: update x509_crt_verify_strings[] in library/x509_crt.c */
103 #define MBEDTLS_X509_BADCERT_EXPIRED 0x01 /**< The certificate validity has expired. */
104 #define MBEDTLS_X509_BADCERT_REVOKED 0x02 /**< The certificate has been revoked (is on a CRL). */
105 #define MBEDTLS_X509_BADCERT_CN_MISMATCH 0x04 /**< The certificate Common Name (CN) does not match with the expected CN. */
106 #define MBEDTLS_X509_BADCERT_NOT_TRUSTED 0x08 /**< The certificate is not correctly signed by the trusted CA. */
107 #define MBEDTLS_X509_BADCRL_NOT_TRUSTED 0x10 /**< The CRL is not correctly signed by the trusted CA. */
108 #define MBEDTLS_X509_BADCRL_EXPIRED 0x20 /**< The CRL is expired. */
109 #define MBEDTLS_X509_BADCERT_MISSING 0x40 /**< Certificate was missing. */
110 #define MBEDTLS_X509_BADCERT_SKIP_VERIFY 0x80 /**< Certificate verification was skipped. */
111 #define MBEDTLS_X509_BADCERT_OTHER 0x0100 /**< Other reason (can be used by verify callback) */
112 #define MBEDTLS_X509_BADCERT_FUTURE 0x0200 /**< The certificate validity starts in the future. */
113 #define MBEDTLS_X509_BADCRL_FUTURE 0x0400 /**< The CRL is from the future */
114 #define MBEDTLS_X509_BADCERT_KEY_USAGE 0x0800 /**< Usage does not match the keyUsage extension. */
115 #define MBEDTLS_X509_BADCERT_EXT_KEY_USAGE 0x1000 /**< Usage does not match the extendedKeyUsage extension. */
116 #define MBEDTLS_X509_BADCERT_NS_CERT_TYPE 0x2000 /**< Usage does not match the nsCertType extension. */
117 #define MBEDTLS_X509_BADCERT_BAD_MD 0x4000 /**< The certificate is signed with an unacceptable hash. */
118 #define MBEDTLS_X509_BADCERT_BAD_PK 0x8000 /**< The certificate is signed with an unacceptable PK alg (eg RSA vs ECDSA). */
119 #define MBEDTLS_X509_BADCERT_BAD_KEY 0x010000 /**< The certificate is signed with an unacceptable key (eg bad curve, RSA too short). */
120 #define MBEDTLS_X509_BADCRL_BAD_MD 0x020000 /**< The CRL is signed with an unacceptable hash. */
121 #define MBEDTLS_X509_BADCRL_BAD_PK 0x040000 /**< The CRL is signed with an unacceptable PK alg (eg RSA vs ECDSA). */
122 #define MBEDTLS_X509_BADCRL_BAD_KEY 0x080000 /**< The CRL is signed with an unacceptable key (eg bad curve, RSA too short). */
123
124 /** \} name X509 Verify codes */
125 /** \} addtogroup x509_module */
126
127 /*
128 * X.509 v3 Subject Alternative Name types.
129 * otherName [0] OtherName,
130 * rfc822Name [1] IA5String,
131 * dNSName [2] IA5String,
132 * x400Address [3] ORAddress,
133 * directoryName [4] Name,
134 * ediPartyName [5] EDIPartyName,
135 * uniformResourceIdentifier [6] IA5String,
136 * iPAddress [7] OCTET STRING,
137 * registeredID [8] OBJECT IDENTIFIER
138 */
139 #define MBEDTLS_X509_SAN_OTHER_NAME 0
140 #define MBEDTLS_X509_SAN_RFC822_NAME 1
141 #define MBEDTLS_X509_SAN_DNS_NAME 2
142 #define MBEDTLS_X509_SAN_X400_ADDRESS_NAME 3
143 #define MBEDTLS_X509_SAN_DIRECTORY_NAME 4
144 #define MBEDTLS_X509_SAN_EDI_PARTY_NAME 5
145 #define MBEDTLS_X509_SAN_UNIFORM_RESOURCE_IDENTIFIER 6
146 #define MBEDTLS_X509_SAN_IP_ADDRESS 7
147 #define MBEDTLS_X509_SAN_REGISTERED_ID 8
148
149 /*
150 * X.509 v3 Key Usage Extension flags
151 * Reminder: update mbedtls_x509_info_key_usage() when adding new flags.
152 */
153 #define MBEDTLS_X509_KU_DIGITAL_SIGNATURE (0x80) /* bit 0 */
154 #define MBEDTLS_X509_KU_NON_REPUDIATION (0x40) /* bit 1 */
155 #define MBEDTLS_X509_KU_KEY_ENCIPHERMENT (0x20) /* bit 2 */
156 #define MBEDTLS_X509_KU_DATA_ENCIPHERMENT (0x10) /* bit 3 */
157 #define MBEDTLS_X509_KU_KEY_AGREEMENT (0x08) /* bit 4 */
158 #define MBEDTLS_X509_KU_KEY_CERT_SIGN (0x04) /* bit 5 */
159 #define MBEDTLS_X509_KU_CRL_SIGN (0x02) /* bit 6 */
160 #define MBEDTLS_X509_KU_ENCIPHER_ONLY (0x01) /* bit 7 */
161 #define MBEDTLS_X509_KU_DECIPHER_ONLY (0x8000) /* bit 8 */
162
163 /*
164 * Netscape certificate types
165 * (http://www.mozilla.org/projects/security/pki/nss/tech-notes/tn3.html)
166 */
167
168 #define MBEDTLS_X509_NS_CERT_TYPE_SSL_CLIENT (0x80) /* bit 0 */
169 #define MBEDTLS_X509_NS_CERT_TYPE_SSL_SERVER (0x40) /* bit 1 */
170 #define MBEDTLS_X509_NS_CERT_TYPE_EMAIL (0x20) /* bit 2 */
171 #define MBEDTLS_X509_NS_CERT_TYPE_OBJECT_SIGNING (0x10) /* bit 3 */
172 #define MBEDTLS_X509_NS_CERT_TYPE_RESERVED (0x08) /* bit 4 */
173 #define MBEDTLS_X509_NS_CERT_TYPE_SSL_CA (0x04) /* bit 5 */
174 #define MBEDTLS_X509_NS_CERT_TYPE_EMAIL_CA (0x02) /* bit 6 */
175 #define MBEDTLS_X509_NS_CERT_TYPE_OBJECT_SIGNING_CA (0x01) /* bit 7 */
176
177 /*
178 * X.509 extension types
179 *
180 * Comments refer to the status for using certificates. Status can be
181 * different for writing certificates or reading CRLs or CSRs.
182 *
183 * Those are defined in oid.h as oid.c needs them in a data structure. Since
184 * these were previously defined here, let's have aliases for compatibility.
185 */
186 #define MBEDTLS_X509_EXT_AUTHORITY_KEY_IDENTIFIER MBEDTLS_OID_X509_EXT_AUTHORITY_KEY_IDENTIFIER
187 #define MBEDTLS_X509_EXT_SUBJECT_KEY_IDENTIFIER MBEDTLS_OID_X509_EXT_SUBJECT_KEY_IDENTIFIER
188 #define MBEDTLS_X509_EXT_KEY_USAGE MBEDTLS_OID_X509_EXT_KEY_USAGE
189 #define MBEDTLS_X509_EXT_CERTIFICATE_POLICIES MBEDTLS_OID_X509_EXT_CERTIFICATE_POLICIES
190 #define MBEDTLS_X509_EXT_POLICY_MAPPINGS MBEDTLS_OID_X509_EXT_POLICY_MAPPINGS
191 #define MBEDTLS_X509_EXT_SUBJECT_ALT_NAME MBEDTLS_OID_X509_EXT_SUBJECT_ALT_NAME /* Supported (DNS) */
192 #define MBEDTLS_X509_EXT_ISSUER_ALT_NAME MBEDTLS_OID_X509_EXT_ISSUER_ALT_NAME
193 #define MBEDTLS_X509_EXT_SUBJECT_DIRECTORY_ATTRS MBEDTLS_OID_X509_EXT_SUBJECT_DIRECTORY_ATTRS
194 #define MBEDTLS_X509_EXT_BASIC_CONSTRAINTS MBEDTLS_OID_X509_EXT_BASIC_CONSTRAINTS /* Supported */
195 #define MBEDTLS_X509_EXT_NAME_CONSTRAINTS MBEDTLS_OID_X509_EXT_NAME_CONSTRAINTS
196 #define MBEDTLS_X509_EXT_POLICY_CONSTRAINTS MBEDTLS_OID_X509_EXT_POLICY_CONSTRAINTS
197 #define MBEDTLS_X509_EXT_EXTENDED_KEY_USAGE MBEDTLS_OID_X509_EXT_EXTENDED_KEY_USAGE
198 #define MBEDTLS_X509_EXT_CRL_DISTRIBUTION_POINTS MBEDTLS_OID_X509_EXT_CRL_DISTRIBUTION_POINTS
199 #define MBEDTLS_X509_EXT_INIHIBIT_ANYPOLICY MBEDTLS_OID_X509_EXT_INIHIBIT_ANYPOLICY
200 #define MBEDTLS_X509_EXT_FRESHEST_CRL MBEDTLS_OID_X509_EXT_FRESHEST_CRL
201 #define MBEDTLS_X509_EXT_NS_CERT_TYPE MBEDTLS_OID_X509_EXT_NS_CERT_TYPE
202
203 /*
204 * Storage format identifiers
205 * Recognized formats: PEM and DER
206 */
207 #define MBEDTLS_X509_FORMAT_DER 1
208 #define MBEDTLS_X509_FORMAT_PEM 2
209
210 #define MBEDTLS_X509_MAX_DN_NAME_SIZE 256 /**< Maximum value size of a DN entry */
211
212 #ifdef __cplusplus
213 extern "C" {
214 #endif
215
216 /**
217 * \addtogroup x509_module
218 * \{ */
219
220 /**
221 * \name Structures for parsing X.509 certificates, CRLs and CSRs
222 * \{
223 */
224
225 /**
226 * Type-length-value structure that allows for ASN1 using DER.
227 */
228 typedef mbedtls_asn1_buf mbedtls_x509_buf;
229
230 /**
231 * Container for ASN1 bit strings.
232 */
233 typedef mbedtls_asn1_bitstring mbedtls_x509_bitstring;
234
235 /**
236 * Container for ASN1 named information objects.
237 * It allows for Relative Distinguished Names (e.g. cn=localhost,ou=code,etc.).
238 */
239 typedef mbedtls_asn1_named_data mbedtls_x509_name;
240
241 /**
242 * Container for a sequence of ASN.1 items
243 */
244 typedef mbedtls_asn1_sequence mbedtls_x509_sequence;
245
246 /** Container for date and time (precision in seconds). */
247 typedef struct mbedtls_x509_time {
248 int year, mon, day; /**< Date. */
249 int hour, min, sec; /**< Time. */
250 }
251 mbedtls_x509_time;
252
253 /**
254 * From RFC 5280 section 4.2.1.6:
255 * OtherName ::= SEQUENCE {
256 * type-id OBJECT IDENTIFIER,
257 * value [0] EXPLICIT ANY DEFINED BY type-id }
258 *
259 * Future versions of the library may add new fields to this structure or
260 * to its embedded union and structure.
261 */
262 typedef struct mbedtls_x509_san_other_name {
263 /**
264 * The type_id is an OID as defined in RFC 5280.
265 * To check the value of the type id, you should use
266 * \p MBEDTLS_OID_CMP with a known OID mbedtls_x509_buf.
267 */
268 mbedtls_x509_buf type_id; /**< The type id. */
269 union {
270 /**
271 * From RFC 4108 section 5:
272 * HardwareModuleName ::= SEQUENCE {
273 * hwType OBJECT IDENTIFIER,
274 * hwSerialNum OCTET STRING }
275 */
276 struct {
277 mbedtls_x509_buf oid; /**< The object identifier. */
278 mbedtls_x509_buf val; /**< The named value. */
279 }
280 hardware_module_name;
281 }
282 value;
283 }
284 mbedtls_x509_san_other_name;
285
286 /**
287 * A structure for holding the parsed Subject Alternative Name,
288 * according to type.
289 *
290 * Future versions of the library may add new fields to this structure or
291 * to its embedded union and structure.
292 */
293 typedef struct mbedtls_x509_subject_alternative_name {
294 int type; /**< The SAN type, value of MBEDTLS_X509_SAN_XXX. */
295 union {
296 mbedtls_x509_san_other_name other_name; /**< The otherName supported type. */
297 mbedtls_x509_buf unstructured_name; /**< The buffer for the unconstructed types. Only rfc822Name, dnsName and uniformResourceIdentifier are currently supported */
298 }
299 san; /**< A union of the supported SAN types */
300 }
301 mbedtls_x509_subject_alternative_name;
302
303 /** \} name Structures for parsing X.509 certificates, CRLs and CSRs */
304
305 /**
306 * \brief Store the certificate DN in printable form into buf;
307 * no more than size characters will be written.
308 *
309 * \param buf Buffer to write to
310 * \param size Maximum size of buffer
311 * \param dn The X509 name to represent
312 *
313 * \return The length of the string written (not including the
314 * terminated nul byte), or a negative error code.
315 */
316 int mbedtls_x509_dn_gets(char *buf, size_t size, const mbedtls_x509_name *dn);
317
318 /**
319 * \brief Return the next relative DN in an X509 name.
320 *
321 * \note Intended use is to compare function result to dn->next
322 * in order to detect boundaries of multi-valued RDNs.
323 *
324 * \param dn Current node in the X509 name
325 *
326 * \return Pointer to the first attribute-value pair of the
327 * next RDN in sequence, or NULL if end is reached.
328 */
mbedtls_x509_dn_get_next(mbedtls_x509_name * dn)329 static inline mbedtls_x509_name *mbedtls_x509_dn_get_next(
330 mbedtls_x509_name *dn)
331 {
332 while (dn->MBEDTLS_PRIVATE(next_merged) && dn->next != NULL) {
333 dn = dn->next;
334 }
335 return dn->next;
336 }
337
338 /**
339 * \brief Store the certificate serial in printable form into buf;
340 * no more than size characters will be written.
341 *
342 * \param buf Buffer to write to
343 * \param size Maximum size of buffer
344 * \param serial The X509 serial to represent
345 *
346 * \return The length of the string written (not including the
347 * terminated nul byte), or a negative error code.
348 */
349 int mbedtls_x509_serial_gets(char *buf, size_t size, const mbedtls_x509_buf *serial);
350
351 /**
352 * \brief Check a given mbedtls_x509_time against the system time
353 * and tell if it's in the past.
354 *
355 * \note Intended usage is "if( is_past( valid_to ) ) ERROR".
356 * Hence the return value of 1 if on internal errors.
357 *
358 * \param to mbedtls_x509_time to check
359 *
360 * \return 1 if the given time is in the past or an error occurred,
361 * 0 otherwise.
362 */
363 int mbedtls_x509_time_is_past(const mbedtls_x509_time *to);
364
365 /**
366 * \brief Check a given mbedtls_x509_time against the system time
367 * and tell if it's in the future.
368 *
369 * \note Intended usage is "if( is_future( valid_from ) ) ERROR".
370 * Hence the return value of 1 if on internal errors.
371 *
372 * \param from mbedtls_x509_time to check
373 *
374 * \return 1 if the given time is in the future or an error occurred,
375 * 0 otherwise.
376 */
377 int mbedtls_x509_time_is_future(const mbedtls_x509_time *from);
378
379 /**
380 * \brief This function parses an item in the SubjectAlternativeNames
381 * extension.
382 *
383 * \param san_buf The buffer holding the raw data item of the subject
384 * alternative name.
385 * \param san The target structure to populate with the parsed presentation
386 * of the subject alternative name encoded in \p san_raw.
387 *
388 * \note Supported GeneralName types, as defined in RFC 5280:
389 * "rfc822Name", "dnsName", "uniformResourceIdentifier" and "hardware_module_name"
390 * of type "otherName", as defined in RFC 4108.
391 *
392 * \note This function should be called on a single raw data of
393 * subject alternative name. For example, after successful
394 * certificate parsing, one must iterate on every item in the
395 * \p crt->subject_alt_names sequence, and pass it to
396 * this function.
397 *
398 * \warning The target structure contains pointers to the raw data of the
399 * parsed certificate, and its lifetime is restricted by the
400 * lifetime of the certificate.
401 *
402 * \return \c 0 on success
403 * \return #MBEDTLS_ERR_X509_FEATURE_UNAVAILABLE for an unsupported
404 * SAN type.
405 * \return Another negative value for any other failure.
406 */
407 int mbedtls_x509_parse_subject_alt_name(const mbedtls_x509_buf *san_buf,
408 mbedtls_x509_subject_alternative_name *san);
409
410 /** \} addtogroup x509_module */
411
412 /*
413 * Internal module functions. You probably do not want to use these unless you
414 * know you do.
415 */
416 int mbedtls_x509_get_name(unsigned char **p, const unsigned char *end,
417 mbedtls_x509_name *cur);
418 int mbedtls_x509_get_alg_null(unsigned char **p, const unsigned char *end,
419 mbedtls_x509_buf *alg);
420 int mbedtls_x509_get_alg(unsigned char **p, const unsigned char *end,
421 mbedtls_x509_buf *alg, mbedtls_x509_buf *params);
422 #if defined(MBEDTLS_X509_RSASSA_PSS_SUPPORT)
423 int mbedtls_x509_get_rsassa_pss_params(const mbedtls_x509_buf *params,
424 mbedtls_md_type_t *md_alg, mbedtls_md_type_t *mgf_md,
425 int *salt_len);
426 #endif
427 int mbedtls_x509_get_sig(unsigned char **p, const unsigned char *end, mbedtls_x509_buf *sig);
428 int mbedtls_x509_get_sig_alg(const mbedtls_x509_buf *sig_oid, const mbedtls_x509_buf *sig_params,
429 mbedtls_md_type_t *md_alg, mbedtls_pk_type_t *pk_alg,
430 void **sig_opts);
431 int mbedtls_x509_get_time(unsigned char **p, const unsigned char *end,
432 mbedtls_x509_time *t);
433 int mbedtls_x509_get_serial(unsigned char **p, const unsigned char *end,
434 mbedtls_x509_buf *serial);
435 int mbedtls_x509_get_ext(unsigned char **p, const unsigned char *end,
436 mbedtls_x509_buf *ext, int tag);
437 #if !defined(MBEDTLS_X509_REMOVE_INFO)
438 int mbedtls_x509_sig_alg_gets(char *buf, size_t size, const mbedtls_x509_buf *sig_oid,
439 mbedtls_pk_type_t pk_alg, mbedtls_md_type_t md_alg,
440 const void *sig_opts);
441 #endif
442 int mbedtls_x509_key_size_helper(char *buf, size_t buf_size, const char *name);
443 int mbedtls_x509_string_to_names(mbedtls_asn1_named_data **head, const char *name);
444 int mbedtls_x509_set_extension(mbedtls_asn1_named_data **head, const char *oid, size_t oid_len,
445 int critical, const unsigned char *val,
446 size_t val_len);
447 int mbedtls_x509_write_extensions(unsigned char **p, unsigned char *start,
448 mbedtls_asn1_named_data *first);
449 int mbedtls_x509_write_names(unsigned char **p, unsigned char *start,
450 mbedtls_asn1_named_data *first);
451 int mbedtls_x509_write_sig(unsigned char **p, unsigned char *start,
452 const char *oid, size_t oid_len,
453 unsigned char *sig, size_t size);
454 int mbedtls_x509_get_ns_cert_type(unsigned char **p,
455 const unsigned char *end,
456 unsigned char *ns_cert_type);
457 int mbedtls_x509_get_key_usage(unsigned char **p,
458 const unsigned char *end,
459 unsigned int *key_usage);
460 int mbedtls_x509_get_subject_alt_name(unsigned char **p,
461 const unsigned char *end,
462 mbedtls_x509_sequence *subject_alt_name);
463 int mbedtls_x509_info_subject_alt_name(char **buf, size_t *size,
464 const mbedtls_x509_sequence
465 *subject_alt_name,
466 const char *prefix);
467 int mbedtls_x509_info_cert_type(char **buf, size_t *size,
468 unsigned char ns_cert_type);
469 int mbedtls_x509_info_key_usage(char **buf, size_t *size,
470 unsigned int key_usage);
471
472 #define MBEDTLS_X509_SAFE_SNPRINTF \
473 do { \
474 if (ret < 0 || (size_t) ret >= n) \
475 return MBEDTLS_ERR_X509_BUFFER_TOO_SMALL; \
476 \
477 n -= (size_t) ret; \
478 p += (size_t) ret; \
479 } while (0)
480
481 #ifdef __cplusplus
482 }
483 #endif
484
485 #endif /* x509.h */
486