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 OR GPL-2.0-or-later
9  */
10 #ifndef MBEDTLS_X509_H
11 #define MBEDTLS_X509_H
12 #include "mbedtls/private_access.h"
13 
14 #include "mbedtls/build_info.h"
15 
16 #include "mbedtls/asn1.h"
17 #include "mbedtls/pk.h"
18 
19 #if defined(MBEDTLS_RSA_C)
20 #include "mbedtls/rsa.h"
21 #endif
22 
23 /**
24  * \addtogroup x509_module
25  * \{
26  */
27 
28 #if !defined(MBEDTLS_X509_MAX_INTERMEDIATE_CA)
29 /**
30  * Maximum number of intermediate CAs in a verification chain.
31  * That is, maximum length of the chain, excluding the end-entity certificate
32  * and the trusted root certificate.
33  *
34  * Set this to a low value to prevent an adversary from making you waste
35  * resources verifying an overlong certificate chain.
36  */
37 #define MBEDTLS_X509_MAX_INTERMEDIATE_CA   8
38 #endif
39 
40 /**
41  * \name X509 Error codes
42  * \{
43  */
44 /** Unavailable feature, e.g. RSA hashing/encryption combination. */
45 #define MBEDTLS_ERR_X509_FEATURE_UNAVAILABLE              -0x2080
46 /** Requested OID is unknown. */
47 #define MBEDTLS_ERR_X509_UNKNOWN_OID                      -0x2100
48 /** The CRT/CRL/CSR format is invalid, e.g. different type expected. */
49 #define MBEDTLS_ERR_X509_INVALID_FORMAT                   -0x2180
50 /** The CRT/CRL/CSR version element is invalid. */
51 #define MBEDTLS_ERR_X509_INVALID_VERSION                  -0x2200
52 /** The serial tag or value is invalid. */
53 #define MBEDTLS_ERR_X509_INVALID_SERIAL                   -0x2280
54 /** The algorithm tag or value is invalid. */
55 #define MBEDTLS_ERR_X509_INVALID_ALG                      -0x2300
56 /** The name tag or value is invalid. */
57 #define MBEDTLS_ERR_X509_INVALID_NAME                     -0x2380
58 /** The date tag or value is invalid. */
59 #define MBEDTLS_ERR_X509_INVALID_DATE                     -0x2400
60 /** The signature tag or value invalid. */
61 #define MBEDTLS_ERR_X509_INVALID_SIGNATURE                -0x2480
62 /** The extension tag or value is invalid. */
63 #define MBEDTLS_ERR_X509_INVALID_EXTENSIONS               -0x2500
64 /** CRT/CRL/CSR has an unsupported version number. */
65 #define MBEDTLS_ERR_X509_UNKNOWN_VERSION                  -0x2580
66 /** Signature algorithm (oid) is unsupported. */
67 #define MBEDTLS_ERR_X509_UNKNOWN_SIG_ALG                  -0x2600
68 /** Signature algorithms do not match. (see \c ::mbedtls_x509_crt sig_oid) */
69 #define MBEDTLS_ERR_X509_SIG_MISMATCH                     -0x2680
70 /** Certificate verification failed, e.g. CRL, CA or signature check failed. */
71 #define MBEDTLS_ERR_X509_CERT_VERIFY_FAILED               -0x2700
72 /** Format not recognized as DER or PEM. */
73 #define MBEDTLS_ERR_X509_CERT_UNKNOWN_FORMAT              -0x2780
74 /** Input invalid. */
75 #define MBEDTLS_ERR_X509_BAD_INPUT_DATA                   -0x2800
76 /** Allocation of memory failed. */
77 #define MBEDTLS_ERR_X509_ALLOC_FAILED                     -0x2880
78 /** Read/write of file failed. */
79 #define MBEDTLS_ERR_X509_FILE_IO_ERROR                    -0x2900
80 /** Destination buffer is too small. */
81 #define MBEDTLS_ERR_X509_BUFFER_TOO_SMALL                 -0x2980
82 /** A fatal error occurred, eg the chain is too long or the vrfy callback failed. */
83 #define MBEDTLS_ERR_X509_FATAL_ERROR                      -0x3000
84 /** \} name X509 Error codes */
85 
86 /**
87  * \name X509 Verify codes
88  * \{
89  */
90 /* Reminder: update x509_crt_verify_strings[] in library/x509_crt.c */
91 #define MBEDTLS_X509_BADCERT_EXPIRED             0x01  /**< The certificate validity has expired. */
92 #define MBEDTLS_X509_BADCERT_REVOKED             0x02  /**< The certificate has been revoked (is on a CRL). */
93 #define MBEDTLS_X509_BADCERT_CN_MISMATCH         0x04  /**< The certificate Common Name (CN) does not match with the expected CN. */
94 #define MBEDTLS_X509_BADCERT_NOT_TRUSTED         0x08  /**< The certificate is not correctly signed by the trusted CA. */
95 #define MBEDTLS_X509_BADCRL_NOT_TRUSTED          0x10  /**< The CRL is not correctly signed by the trusted CA. */
96 #define MBEDTLS_X509_BADCRL_EXPIRED              0x20  /**< The CRL is expired. */
97 #define MBEDTLS_X509_BADCERT_MISSING             0x40  /**< Certificate was missing. */
98 #define MBEDTLS_X509_BADCERT_SKIP_VERIFY         0x80  /**< Certificate verification was skipped. */
99 #define MBEDTLS_X509_BADCERT_OTHER             0x0100  /**< Other reason (can be used by verify callback) */
100 #define MBEDTLS_X509_BADCERT_FUTURE            0x0200  /**< The certificate validity starts in the future. */
101 #define MBEDTLS_X509_BADCRL_FUTURE             0x0400  /**< The CRL is from the future */
102 #define MBEDTLS_X509_BADCERT_KEY_USAGE         0x0800  /**< Usage does not match the keyUsage extension. */
103 #define MBEDTLS_X509_BADCERT_EXT_KEY_USAGE     0x1000  /**< Usage does not match the extendedKeyUsage extension. */
104 #define MBEDTLS_X509_BADCERT_NS_CERT_TYPE      0x2000  /**< Usage does not match the nsCertType extension. */
105 #define MBEDTLS_X509_BADCERT_BAD_MD            0x4000  /**< The certificate is signed with an unacceptable hash. */
106 #define MBEDTLS_X509_BADCERT_BAD_PK            0x8000  /**< The certificate is signed with an unacceptable PK alg (eg RSA vs ECDSA). */
107 #define MBEDTLS_X509_BADCERT_BAD_KEY         0x010000  /**< The certificate is signed with an unacceptable key (eg bad curve, RSA too short). */
108 #define MBEDTLS_X509_BADCRL_BAD_MD           0x020000  /**< The CRL is signed with an unacceptable hash. */
109 #define MBEDTLS_X509_BADCRL_BAD_PK           0x040000  /**< The CRL is signed with an unacceptable PK alg (eg RSA vs ECDSA). */
110 #define MBEDTLS_X509_BADCRL_BAD_KEY          0x080000  /**< The CRL is signed with an unacceptable key (eg bad curve, RSA too short). */
111 
112 /** \} name X509 Verify codes */
113 /** \} addtogroup x509_module */
114 
115 /*
116  * X.509 v3 Subject Alternative Name types.
117  *      otherName                       [0]     OtherName,
118  *      rfc822Name                      [1]     IA5String,
119  *      dNSName                         [2]     IA5String,
120  *      x400Address                     [3]     ORAddress,
121  *      directoryName                   [4]     Name,
122  *      ediPartyName                    [5]     EDIPartyName,
123  *      uniformResourceIdentifier       [6]     IA5String,
124  *      iPAddress                       [7]     OCTET STRING,
125  *      registeredID                    [8]     OBJECT IDENTIFIER
126  */
127 #define MBEDTLS_X509_SAN_OTHER_NAME                      0
128 #define MBEDTLS_X509_SAN_RFC822_NAME                     1
129 #define MBEDTLS_X509_SAN_DNS_NAME                        2
130 #define MBEDTLS_X509_SAN_X400_ADDRESS_NAME               3
131 #define MBEDTLS_X509_SAN_DIRECTORY_NAME                  4
132 #define MBEDTLS_X509_SAN_EDI_PARTY_NAME                  5
133 #define MBEDTLS_X509_SAN_UNIFORM_RESOURCE_IDENTIFIER     6
134 #define MBEDTLS_X509_SAN_IP_ADDRESS                      7
135 #define MBEDTLS_X509_SAN_REGISTERED_ID                   8
136 
137 /*
138  * X.509 v3 Key Usage Extension flags
139  * Reminder: update mbedtls_x509_info_key_usage() when adding new flags.
140  */
141 #define MBEDTLS_X509_KU_DIGITAL_SIGNATURE            (0x80)  /* bit 0 */
142 #define MBEDTLS_X509_KU_NON_REPUDIATION              (0x40)  /* bit 1 */
143 #define MBEDTLS_X509_KU_KEY_ENCIPHERMENT             (0x20)  /* bit 2 */
144 #define MBEDTLS_X509_KU_DATA_ENCIPHERMENT            (0x10)  /* bit 3 */
145 #define MBEDTLS_X509_KU_KEY_AGREEMENT                (0x08)  /* bit 4 */
146 #define MBEDTLS_X509_KU_KEY_CERT_SIGN                (0x04)  /* bit 5 */
147 #define MBEDTLS_X509_KU_CRL_SIGN                     (0x02)  /* bit 6 */
148 #define MBEDTLS_X509_KU_ENCIPHER_ONLY                (0x01)  /* bit 7 */
149 #define MBEDTLS_X509_KU_DECIPHER_ONLY              (0x8000)  /* bit 8 */
150 
151 /*
152  * Netscape certificate types
153  * (http://www.mozilla.org/projects/security/pki/nss/tech-notes/tn3.html)
154  */
155 
156 #define MBEDTLS_X509_NS_CERT_TYPE_SSL_CLIENT         (0x80)  /* bit 0 */
157 #define MBEDTLS_X509_NS_CERT_TYPE_SSL_SERVER         (0x40)  /* bit 1 */
158 #define MBEDTLS_X509_NS_CERT_TYPE_EMAIL              (0x20)  /* bit 2 */
159 #define MBEDTLS_X509_NS_CERT_TYPE_OBJECT_SIGNING     (0x10)  /* bit 3 */
160 #define MBEDTLS_X509_NS_CERT_TYPE_RESERVED           (0x08)  /* bit 4 */
161 #define MBEDTLS_X509_NS_CERT_TYPE_SSL_CA             (0x04)  /* bit 5 */
162 #define MBEDTLS_X509_NS_CERT_TYPE_EMAIL_CA           (0x02)  /* bit 6 */
163 #define MBEDTLS_X509_NS_CERT_TYPE_OBJECT_SIGNING_CA  (0x01)  /* bit 7 */
164 
165 /*
166  * X.509 extension types
167  *
168  * Comments refer to the status for using certificates. Status can be
169  * different for writing certificates or reading CRLs or CSRs.
170  */
171 #define MBEDTLS_X509_EXT_AUTHORITY_KEY_IDENTIFIER (1 << 0)
172 #define MBEDTLS_X509_EXT_SUBJECT_KEY_IDENTIFIER   (1 << 1)
173 #define MBEDTLS_X509_EXT_KEY_USAGE                (1 << 2)
174 #define MBEDTLS_X509_EXT_CERTIFICATE_POLICIES     (1 << 3)
175 #define MBEDTLS_X509_EXT_POLICY_MAPPINGS          (1 << 4)
176 #define MBEDTLS_X509_EXT_SUBJECT_ALT_NAME         (1 << 5)  /* Supported (DNS) */
177 #define MBEDTLS_X509_EXT_ISSUER_ALT_NAME          (1 << 6)
178 #define MBEDTLS_X509_EXT_SUBJECT_DIRECTORY_ATTRS  (1 << 7)
179 #define MBEDTLS_X509_EXT_BASIC_CONSTRAINTS        (1 << 8)  /* Supported */
180 #define MBEDTLS_X509_EXT_NAME_CONSTRAINTS         (1 << 9)
181 #define MBEDTLS_X509_EXT_POLICY_CONSTRAINTS       (1 << 10)
182 #define MBEDTLS_X509_EXT_EXTENDED_KEY_USAGE       (1 << 11)
183 #define MBEDTLS_X509_EXT_CRL_DISTRIBUTION_POINTS  (1 << 12)
184 #define MBEDTLS_X509_EXT_INIHIBIT_ANYPOLICY       (1 << 13)
185 #define MBEDTLS_X509_EXT_FRESHEST_CRL             (1 << 14)
186 #define MBEDTLS_X509_EXT_NS_CERT_TYPE             (1 << 16)
187 
188 /*
189  * Storage format identifiers
190  * Recognized formats: PEM and DER
191  */
192 #define MBEDTLS_X509_FORMAT_DER                 1
193 #define MBEDTLS_X509_FORMAT_PEM                 2
194 
195 #define MBEDTLS_X509_MAX_DN_NAME_SIZE         256 /**< Maximum value size of a DN entry */
196 
197 #ifdef __cplusplus
198 extern "C" {
199 #endif
200 
201 /**
202  * \addtogroup x509_module
203  * \{ */
204 
205 /**
206  * \name Structures for parsing X.509 certificates, CRLs and CSRs
207  * \{
208  */
209 
210 /**
211  * Type-length-value structure that allows for ASN1 using DER.
212  */
213 typedef mbedtls_asn1_buf mbedtls_x509_buf;
214 
215 /**
216  * Container for ASN1 bit strings.
217  */
218 typedef mbedtls_asn1_bitstring mbedtls_x509_bitstring;
219 
220 /**
221  * Container for ASN1 named information objects.
222  * It allows for Relative Distinguished Names (e.g. cn=localhost,ou=code,etc.).
223  */
224 typedef mbedtls_asn1_named_data mbedtls_x509_name;
225 
226 /**
227  * Container for a sequence of ASN.1 items
228  */
229 typedef mbedtls_asn1_sequence mbedtls_x509_sequence;
230 
231 /*
232  * Container for the fields of the Authority Key Identifier object
233  */
234 typedef struct mbedtls_x509_authority {
235     mbedtls_x509_buf keyIdentifier;
236     mbedtls_x509_sequence authorityCertIssuer;
237     mbedtls_x509_buf authorityCertSerialNumber;
238     mbedtls_x509_buf raw;
239 }
240 mbedtls_x509_authority;
241 
242 /** Container for date and time (precision in seconds). */
243 typedef struct mbedtls_x509_time {
244     int year, mon, day;         /**< Date. */
245     int hour, min, sec;         /**< Time. */
246 }
247 mbedtls_x509_time;
248 
249 /**
250  * From RFC 5280 section 4.2.1.6:
251  * OtherName ::= SEQUENCE {
252  *      type-id    OBJECT IDENTIFIER,
253  *      value      [0] EXPLICIT ANY DEFINED BY type-id }
254  *
255  * Future versions of the library may add new fields to this structure or
256  * to its embedded union and structure.
257  */
258 typedef struct mbedtls_x509_san_other_name {
259     /**
260      * The type_id is an OID as defined in RFC 5280.
261      * To check the value of the type id, you should use
262      * \p MBEDTLS_OID_CMP with a known OID mbedtls_x509_buf.
263      */
264     mbedtls_x509_buf type_id;                   /**< The type id. */
265     union {
266         /**
267          * From RFC 4108 section 5:
268          * HardwareModuleName ::= SEQUENCE {
269          *                         hwType OBJECT IDENTIFIER,
270          *                         hwSerialNum OCTET STRING }
271          */
272         struct {
273             mbedtls_x509_buf oid;               /**< The object identifier. */
274             mbedtls_x509_buf val;               /**< The named value. */
275         }
276         hardware_module_name;
277     }
278     value;
279 }
280 mbedtls_x509_san_other_name;
281 
282 /**
283  * A structure for holding the parsed Subject Alternative Name,
284  * according to type.
285  *
286  * Future versions of the library may add new fields to this structure or
287  * to its embedded union and structure.
288  */
289 typedef struct mbedtls_x509_subject_alternative_name {
290     int type;                              /**< The SAN type, value of MBEDTLS_X509_SAN_XXX. */
291     union {
292         mbedtls_x509_san_other_name other_name;
293         mbedtls_x509_name directory_name;
294         mbedtls_x509_buf unstructured_name; /**< The buffer for the unstructured types. rfc822Name, dnsName and uniformResourceIdentifier are currently supported. */
295     }
296     san; /**< A union of the supported SAN types */
297 }
298 mbedtls_x509_subject_alternative_name;
299 
300 typedef struct mbedtls_x509_san_list {
301     mbedtls_x509_subject_alternative_name node;
302     struct mbedtls_x509_san_list *next;
303 }
304 mbedtls_x509_san_list;
305 
306 /** \} name Structures for parsing X.509 certificates, CRLs and CSRs */
307 /** \} addtogroup x509_module */
308 
309 /**
310  * \brief          Store the certificate DN in printable form into buf;
311  *                 no more than size characters will be written.
312  *
313  * \param buf      Buffer to write to
314  * \param size     Maximum size of buffer
315  * \param dn       The X509 name to represent
316  *
317  * \return         The length of the string written (not including the
318  *                 terminated nul byte), or a negative error code.
319  */
320 int mbedtls_x509_dn_gets(char *buf, size_t size, const mbedtls_x509_name *dn);
321 
322 /**
323  * \brief            Convert the certificate DN string \p name into
324  *                   a linked list of mbedtls_x509_name (equivalent to
325  *                   mbedtls_asn1_named_data).
326  *
327  * \note             This function allocates a linked list, and places the head
328  *                   pointer in \p head. This list must later be freed by a
329  *                   call to mbedtls_asn1_free_named_data_list().
330  *
331  * \param[out] head  Address in which to store the pointer to the head of the
332  *                   allocated list of mbedtls_x509_name. Must point to NULL on
333  *                   entry.
334  * \param[in] name   The string representation of a DN to convert
335  *
336  * \return           0 on success, or a negative error code.
337  */
338 int mbedtls_x509_string_to_names(mbedtls_asn1_named_data **head, const char *name);
339 
340 /**
341  * \brief          Return the next relative DN in an X509 name.
342  *
343  * \note           Intended use is to compare function result to dn->next
344  *                 in order to detect boundaries of multi-valued RDNs.
345  *
346  * \param dn       Current node in the X509 name
347  *
348  * \return         Pointer to the first attribute-value pair of the
349  *                 next RDN in sequence, or NULL if end is reached.
350  */
mbedtls_x509_dn_get_next(mbedtls_x509_name * dn)351 static inline mbedtls_x509_name *mbedtls_x509_dn_get_next(
352     mbedtls_x509_name *dn)
353 {
354     while (dn->MBEDTLS_PRIVATE(next_merged) && dn->next != NULL) {
355         dn = dn->next;
356     }
357     return dn->next;
358 }
359 
360 /**
361  * \brief          Store the certificate serial in printable form into buf;
362  *                 no more than size characters will be written.
363  *
364  * \param buf      Buffer to write to
365  * \param size     Maximum size of buffer
366  * \param serial   The X509 serial to represent
367  *
368  * \return         The length of the string written (not including the
369  *                 terminated nul byte), or a negative error code.
370  */
371 int mbedtls_x509_serial_gets(char *buf, size_t size, const mbedtls_x509_buf *serial);
372 
373 /**
374  * \brief          Compare pair of mbedtls_x509_time.
375  *
376  * \param t1       mbedtls_x509_time to compare
377  * \param t2       mbedtls_x509_time to compare
378  *
379  * \return         < 0 if t1 is before t2
380  *                   0 if t1 equals t2
381  *                 > 0 if t1 is after t2
382  */
383 int mbedtls_x509_time_cmp(const mbedtls_x509_time *t1, const mbedtls_x509_time *t2);
384 
385 #if defined(MBEDTLS_HAVE_TIME_DATE)
386 /**
387  * \brief          Fill mbedtls_x509_time with provided mbedtls_time_t.
388  *
389  * \param tt       mbedtls_time_t to convert
390  * \param now      mbedtls_x509_time to fill with converted mbedtls_time_t
391  *
392  * \return         \c 0 on success
393  * \return         A non-zero return value on failure.
394  */
395 int mbedtls_x509_time_gmtime(mbedtls_time_t tt, mbedtls_x509_time *now);
396 #endif /* MBEDTLS_HAVE_TIME_DATE */
397 
398 /**
399  * \brief          Check a given mbedtls_x509_time against the system time
400  *                 and tell if it's in the past.
401  *
402  * \note           Intended usage is "if( is_past( valid_to ) ) ERROR".
403  *                 Hence the return value of 1 if on internal errors.
404  *
405  * \param to       mbedtls_x509_time to check
406  *
407  * \return         1 if the given time is in the past or an error occurred,
408  *                 0 otherwise.
409  */
410 int mbedtls_x509_time_is_past(const mbedtls_x509_time *to);
411 
412 /**
413  * \brief          Check a given mbedtls_x509_time against the system time
414  *                 and tell if it's in the future.
415  *
416  * \note           Intended usage is "if( is_future( valid_from ) ) ERROR".
417  *                 Hence the return value of 1 if on internal errors.
418  *
419  * \param from     mbedtls_x509_time to check
420  *
421  * \return         1 if the given time is in the future or an error occurred,
422  *                 0 otherwise.
423  */
424 int mbedtls_x509_time_is_future(const mbedtls_x509_time *from);
425 
426 /**
427  * \brief          This function parses an item in the SubjectAlternativeNames
428  *                 extension. Please note that this function might allocate
429  *                 additional memory for a subject alternative name, thus
430  *                 mbedtls_x509_free_subject_alt_name has to be called
431  *                 to dispose of this additional memory afterwards.
432  *
433  * \param san_buf  The buffer holding the raw data item of the subject
434  *                 alternative name.
435  * \param san      The target structure to populate with the parsed presentation
436  *                 of the subject alternative name encoded in \p san_buf.
437  *
438  * \note           Supported GeneralName types, as defined in RFC 5280:
439  *                 "rfc822Name", "dnsName", "directoryName",
440  *                 "uniformResourceIdentifier" and "hardware_module_name"
441  *                 of type "otherName", as defined in RFC 4108.
442  *
443  * \note           This function should be called on a single raw data of
444  *                 subject alternative name. For example, after successful
445  *                 certificate parsing, one must iterate on every item in the
446  *                 \c crt->subject_alt_names sequence, and pass it to
447  *                 this function.
448  *
449  * \warning        The target structure contains pointers to the raw data of the
450  *                 parsed certificate, and its lifetime is restricted by the
451  *                 lifetime of the certificate.
452  *
453  * \return         \c 0 on success
454  * \return         #MBEDTLS_ERR_X509_FEATURE_UNAVAILABLE for an unsupported
455  *                 SAN type.
456  * \return         Another negative value for any other failure.
457  */
458 int mbedtls_x509_parse_subject_alt_name(const mbedtls_x509_buf *san_buf,
459                                         mbedtls_x509_subject_alternative_name *san);
460 /**
461  * \brief          Unallocate all data related to subject alternative name
462  *
463  * \param san      SAN structure - extra memory owned by this structure will be freed
464  */
465 void mbedtls_x509_free_subject_alt_name(mbedtls_x509_subject_alternative_name *san);
466 
467 /**
468  * \brief          This function parses a CN string as an IP address.
469  *
470  * \param cn       The CN string to parse. CN string MUST be null-terminated.
471  * \param dst      The target buffer to populate with the binary IP address.
472  *                 The buffer MUST be 16 bytes to save IPv6, and should be
473  *                 4-byte aligned if the result will be used as struct in_addr.
474  *                 e.g. uint32_t dst[4]
475  *
476  * \note           \p cn is parsed as an IPv6 address if string contains ':',
477  *                 else \p cn is parsed as an IPv4 address.
478  *
479  * \return         Length of binary IP address; num bytes written to target.
480  * \return         \c 0 on failure to parse CN string as an IP address.
481  */
482 size_t mbedtls_x509_crt_parse_cn_inet_pton(const char *cn, void *dst);
483 
484 #define MBEDTLS_X509_SAFE_SNPRINTF                          \
485     do {                                                    \
486         if (ret < 0 || (size_t) ret >= n)                  \
487         return MBEDTLS_ERR_X509_BUFFER_TOO_SMALL;    \
488                                                           \
489         n -= (size_t) ret;                                  \
490         p += (size_t) ret;                                  \
491     } while (0)
492 
493 #ifdef __cplusplus
494 }
495 #endif
496 
497 #endif /* MBEDTLS_X509_H */
498