1/*
2 * Copyright 2016 The OpenSSL Project Authors. All Rights Reserved.
3 *
4 * Licensed under the OpenSSL license (the "License"). You may not use
5 * this file except in compliance with the License. You can obtain a copy
6 * in the file LICENSE in the source distribution or at
7 * https://www.openssl.org/source/license.html
8 */
9
10#ifndef HEADER_CT_H
11# define HEADER_CT_H
12
13# include <openssl/opensslconf.h>
14
15# ifndef OPENSSL_NO_CT
16# include <openssl/ossl_typ.h>
17# include <openssl/safestack.h>
18# include <openssl/x509.h>
19# ifdef __cplusplus
20extern "C" {
21# endif
22
23
24/* Minimum RSA key size, from RFC6962 */
25# define SCT_MIN_RSA_BITS 2048
26
27/* All hashes are SHA256 in v1 of Certificate Transparency */
28# define CT_V1_HASHLEN SHA256_DIGEST_LENGTH
29
30typedef enum {
31 CT_LOG_ENTRY_TYPE_NOT_SET = -1,
32 CT_LOG_ENTRY_TYPE_X509 = 0,
33 CT_LOG_ENTRY_TYPE_PRECERT = 1
34} ct_log_entry_type_t;
35
36typedef enum {
37 SCT_VERSION_NOT_SET = -1,
38 SCT_VERSION_V1 = 0
39} sct_version_t;
40
41typedef enum {
42 SCT_SOURCE_UNKNOWN,
43 SCT_SOURCE_TLS_EXTENSION,
44 SCT_SOURCE_X509V3_EXTENSION,
45 SCT_SOURCE_OCSP_STAPLED_RESPONSE
46} sct_source_t;
47
48typedef enum {
49 SCT_VALIDATION_STATUS_NOT_SET,
50 SCT_VALIDATION_STATUS_UNKNOWN_LOG,
51 SCT_VALIDATION_STATUS_VALID,
52 SCT_VALIDATION_STATUS_INVALID,
53 SCT_VALIDATION_STATUS_UNVERIFIED,
54 SCT_VALIDATION_STATUS_UNKNOWN_VERSION
55} sct_validation_status_t;
56
57DEFINE_STACK_OF(SCT)
58DEFINE_STACK_OF(CTLOG)
59
60/******************************************
61 * CT policy evaluation context functions *
62 ******************************************/
63
64/*
65 * Creates a new, empty policy evaluation context.
66 * The caller is responsible for calling CT_POLICY_EVAL_CTX_free when finished
67 * with the CT_POLICY_EVAL_CTX.
68 */
69CT_POLICY_EVAL_CTX *CT_POLICY_EVAL_CTX_new(void);
70
71/* Deletes a policy evaluation context and anything it owns. */
72void CT_POLICY_EVAL_CTX_free(CT_POLICY_EVAL_CTX *ctx);
73
74/* Gets the peer certificate that the SCTs are for */
75X509* CT_POLICY_EVAL_CTX_get0_cert(const CT_POLICY_EVAL_CTX *ctx);
76
77/*
78 * Sets the certificate associated with the received SCTs.
79 * Increments the reference count of cert.
80 * Returns 1 on success, 0 otherwise.
81 */
82int CT_POLICY_EVAL_CTX_set1_cert(CT_POLICY_EVAL_CTX *ctx, X509 *cert);
83
84/* Gets the issuer of the aforementioned certificate */
85X509* CT_POLICY_EVAL_CTX_get0_issuer(const CT_POLICY_EVAL_CTX *ctx);
86
87/*
88 * Sets the issuer of the certificate associated with the received SCTs.
89 * Increments the reference count of issuer.
90 * Returns 1 on success, 0 otherwise.
91 */
92int CT_POLICY_EVAL_CTX_set1_issuer(CT_POLICY_EVAL_CTX *ctx, X509 *issuer);
93
94/* Gets the CT logs that are trusted sources of SCTs */
95const CTLOG_STORE *CT_POLICY_EVAL_CTX_get0_log_store(const CT_POLICY_EVAL_CTX *ctx);
96
97/* Sets the log store that is in use. It must outlive the CT_POLICY_EVAL_CTX. */
98void CT_POLICY_EVAL_CTX_set_shared_CTLOG_STORE(CT_POLICY_EVAL_CTX *ctx,
99 CTLOG_STORE *log_store);
100
101/*
102 * Gets the time, in milliseconds since the Unix epoch, that will be used as the
103 * current time when checking whether an SCT was issued in the future.
104 * Such SCTs will fail validation, as required by RFC6962.
105 */
106uint64_t CT_POLICY_EVAL_CTX_get_time(const CT_POLICY_EVAL_CTX *ctx);
107
108/*
109 * Sets the time to evaluate SCTs against, in milliseconds since the Unix epoch.
110 * If an SCT's timestamp is after this time, it will be interpreted as having
111 * been issued in the future. RFC6962 states that "TLS clients MUST reject SCTs
112 * whose timestamp is in the future", so an SCT will not validate in this case.
113 */
114void CT_POLICY_EVAL_CTX_set_time(CT_POLICY_EVAL_CTX *ctx, uint64_t time_in_ms);
115
116/*****************
117 * SCT functions *
118 *****************/
119
120/*
121 * Creates a new, blank SCT.
122 * The caller is responsible for calling SCT_free when finished with the SCT.
123 */
124SCT *SCT_new(void);
125
126/*
127 * Creates a new SCT from some base64-encoded strings.
128 * The caller is responsible for calling SCT_free when finished with the SCT.
129 */
130SCT *SCT_new_from_base64(unsigned char version,
131 const char *logid_base64,
132 ct_log_entry_type_t entry_type,
133 uint64_t timestamp,
134 const char *extensions_base64,
135 const char *signature_base64);
136
137/*
138 * Frees the SCT and the underlying data structures.
139 */
140void SCT_free(SCT *sct);
141
142/*
143 * Free a stack of SCTs, and the underlying SCTs themselves.
144 * Intended to be compatible with X509V3_EXT_FREE.
145 */
146void SCT_LIST_free(STACK_OF(SCT) *a);
147
148/*
149 * Returns the version of the SCT.
150 */
151sct_version_t SCT_get_version(const SCT *sct);
152
153/*
154 * Set the version of an SCT.
155 * Returns 1 on success, 0 if the version is unrecognized.
156 */
157__owur int SCT_set_version(SCT *sct, sct_version_t version);
158
159/*
160 * Returns the log entry type of the SCT.
161 */
162ct_log_entry_type_t SCT_get_log_entry_type(const SCT *sct);
163
164/*
165 * Set the log entry type of an SCT.
166 * Returns 1 on success, 0 otherwise.
167 */
168__owur int SCT_set_log_entry_type(SCT *sct, ct_log_entry_type_t entry_type);
169
170/*
171 * Gets the ID of the log that an SCT came from.
172 * Ownership of the log ID remains with the SCT.
173 * Returns the length of the log ID.
174 */
175size_t SCT_get0_log_id(const SCT *sct, unsigned char **log_id);
176
177/*
178 * Set the log ID of an SCT to point directly to the *log_id specified.
179 * The SCT takes ownership of the specified pointer.
180 * Returns 1 on success, 0 otherwise.
181 */
182__owur int SCT_set0_log_id(SCT *sct, unsigned char *log_id, size_t log_id_len);
183
184/*
185 * Set the log ID of an SCT.
186 * This makes a copy of the log_id.
187 * Returns 1 on success, 0 otherwise.
188 */
189__owur int SCT_set1_log_id(SCT *sct, const unsigned char *log_id,
190 size_t log_id_len);
191
192/*
193 * Returns the timestamp for the SCT (epoch time in milliseconds).
194 */
195uint64_t SCT_get_timestamp(const SCT *sct);
196
197/*
198 * Set the timestamp of an SCT (epoch time in milliseconds).
199 */
200void SCT_set_timestamp(SCT *sct, uint64_t timestamp);
201
202/*
203 * Return the NID for the signature used by the SCT.
204 * For CT v1, this will be either NID_sha256WithRSAEncryption or
205 * NID_ecdsa_with_SHA256 (or NID_undef if incorrect/unset).
206 */
207int SCT_get_signature_nid(const SCT *sct);
208
209/*
210 * Set the signature type of an SCT
211 * For CT v1, this should be either NID_sha256WithRSAEncryption or
212 * NID_ecdsa_with_SHA256.
213 * Returns 1 on success, 0 otherwise.
214 */
215__owur int SCT_set_signature_nid(SCT *sct, int nid);
216
217/*
218 * Set *ext to point to the extension data for the SCT. ext must not be NULL.
219 * The SCT retains ownership of this pointer.
220 * Returns length of the data pointed to.
221 */
222size_t SCT_get0_extensions(const SCT *sct, unsigned char **ext);
223
224/*
225 * Set the extensions of an SCT to point directly to the *ext specified.
226 * The SCT takes ownership of the specified pointer.
227 */
228void SCT_set0_extensions(SCT *sct, unsigned char *ext, size_t ext_len);
229
230/*
231 * Set the extensions of an SCT.
232 * This takes a copy of the ext.
233 * Returns 1 on success, 0 otherwise.
234 */
235__owur int SCT_set1_extensions(SCT *sct, const unsigned char *ext,
236 size_t ext_len);
237
238/*
239 * Set *sig to point to the signature for the SCT. sig must not be NULL.
240 * The SCT retains ownership of this pointer.
241 * Returns length of the data pointed to.
242 */
243size_t SCT_get0_signature(const SCT *sct, unsigned char **sig);
244
245/*
246 * Set the signature of an SCT to point directly to the *sig specified.
247 * The SCT takes ownership of the specified pointer.
248 */
249void SCT_set0_signature(SCT *sct, unsigned char *sig, size_t sig_len);
250
251/*
252 * Set the signature of an SCT to be a copy of the *sig specified.
253 * Returns 1 on success, 0 otherwise.
254 */
255__owur int SCT_set1_signature(SCT *sct, const unsigned char *sig,
256 size_t sig_len);
257
258/*
259 * The origin of this SCT, e.g. TLS extension, OCSP response, etc.
260 */
261sct_source_t SCT_get_source(const SCT *sct);
262
263/*
264 * Set the origin of this SCT, e.g. TLS extension, OCSP response, etc.
265 * Returns 1 on success, 0 otherwise.
266 */
267__owur int SCT_set_source(SCT *sct, sct_source_t source);
268
269/*
270 * Returns a text string describing the validation status of |sct|.
271 */
272const char *SCT_validation_status_string(const SCT *sct);
273
274/*
275 * Pretty-prints an |sct| to |out|.
276 * It will be indented by the number of spaces specified by |indent|.
277 * If |logs| is not NULL, it will be used to lookup the CT log that the SCT came
278 * from, so that the log name can be printed.
279 */
280void SCT_print(const SCT *sct, BIO *out, int indent, const CTLOG_STORE *logs);
281
282/*
283 * Pretty-prints an |sct_list| to |out|.
284 * It will be indented by the number of spaces specified by |indent|.
285 * SCTs will be delimited by |separator|.
286 * If |logs| is not NULL, it will be used to lookup the CT log that each SCT
287 * came from, so that the log names can be printed.
288 */
289void SCT_LIST_print(const STACK_OF(SCT) *sct_list, BIO *out, int indent,
290 const char *separator, const CTLOG_STORE *logs);
291
292/*
293 * Gets the last result of validating this SCT.
294 * If it has not been validated yet, returns SCT_VALIDATION_STATUS_NOT_SET.
295 */
296sct_validation_status_t SCT_get_validation_status(const SCT *sct);
297
298/*
299 * Validates the given SCT with the provided context.
300 * Sets the "validation_status" field of the SCT.
301 * Returns 1 if the SCT is valid and the signature verifies.
302 * Returns 0 if the SCT is invalid or could not be verified.
303 * Returns -1 if an error occurs.
304 */
305__owur int SCT_validate(SCT *sct, const CT_POLICY_EVAL_CTX *ctx);
306
307/*
308 * Validates the given list of SCTs with the provided context.
309 * Sets the "validation_status" field of each SCT.
310 * Returns 1 if there are no invalid SCTs and all signatures verify.
311 * Returns 0 if at least one SCT is invalid or could not be verified.
312 * Returns a negative integer if an error occurs.
313 */
314__owur int SCT_LIST_validate(const STACK_OF(SCT) *scts,
315 CT_POLICY_EVAL_CTX *ctx);
316
317
318/*********************************
319 * SCT parsing and serialisation *
320 *********************************/
321
322/*
323 * Serialize (to TLS format) a stack of SCTs and return the length.
324 * "a" must not be NULL.
325 * If "pp" is NULL, just return the length of what would have been serialized.
326 * If "pp" is not NULL and "*pp" is null, function will allocate a new pointer
327 * for data that caller is responsible for freeing (only if function returns
328 * successfully).
329 * If "pp" is NULL and "*pp" is not NULL, caller is responsible for ensuring
330 * that "*pp" is large enough to accept all of the serialized data.
331 * Returns < 0 on error, >= 0 indicating bytes written (or would have been)
332 * on success.
333 */
334__owur int i2o_SCT_LIST(const STACK_OF(SCT) *a, unsigned char **pp);
335
336/*
337 * Convert TLS format SCT list to a stack of SCTs.
338 * If "a" or "*a" is NULL, a new stack will be created that the caller is
339 * responsible for freeing (by calling SCT_LIST_free).
340 * "**pp" and "*pp" must not be NULL.
341 * Upon success, "*pp" will point to after the last bytes read, and a stack
342 * will be returned.
343 * Upon failure, a NULL pointer will be returned, and the position of "*pp" is
344 * not defined.
345 */
346STACK_OF(SCT) *o2i_SCT_LIST(STACK_OF(SCT) **a, const unsigned char **pp,
347 size_t len);
348
349/*
350 * Serialize (to DER format) a stack of SCTs and return the length.
351 * "a" must not be NULL.
352 * If "pp" is NULL, just returns the length of what would have been serialized.
353 * If "pp" is not NULL and "*pp" is null, function will allocate a new pointer
354 * for data that caller is responsible for freeing (only if function returns
355 * successfully).
356 * If "pp" is NULL and "*pp" is not NULL, caller is responsible for ensuring
357 * that "*pp" is large enough to accept all of the serialized data.
358 * Returns < 0 on error, >= 0 indicating bytes written (or would have been)
359 * on success.
360 */
361__owur int i2d_SCT_LIST(const STACK_OF(SCT) *a, unsigned char **pp);
362
363/*
364 * Parses an SCT list in DER format and returns it.
365 * If "a" or "*a" is NULL, a new stack will be created that the caller is
366 * responsible for freeing (by calling SCT_LIST_free).
367 * "**pp" and "*pp" must not be NULL.
368 * Upon success, "*pp" will point to after the last bytes read, and a stack
369 * will be returned.
370 * Upon failure, a NULL pointer will be returned, and the position of "*pp" is
371 * not defined.
372 */
373STACK_OF(SCT) *d2i_SCT_LIST(STACK_OF(SCT) **a, const unsigned char **pp,
374 long len);
375
376/*
377 * Serialize (to TLS format) an |sct| and write it to |out|.
378 * If |out| is null, no SCT will be output but the length will still be returned.
379 * If |out| points to a null pointer, a string will be allocated to hold the
380 * TLS-format SCT. It is the responsibility of the caller to free it.
381 * If |out| points to an allocated string, the TLS-format SCT will be written
382 * to it.
383 * The length of the SCT in TLS format will be returned.
384 */
385__owur int i2o_SCT(const SCT *sct, unsigned char **out);
386
387/*
388 * Parses an SCT in TLS format and returns it.
389 * If |psct| is not null, it will end up pointing to the parsed SCT. If it
390 * already points to a non-null pointer, the pointer will be free'd.
391 * |in| should be a pointer to a string containing the TLS-format SCT.
392 * |in| will be advanced to the end of the SCT if parsing succeeds.
393 * |len| should be the length of the SCT in |in|.
394 * Returns NULL if an error occurs.
395 * If the SCT is an unsupported version, only the SCT's 'sct' and 'sct_len'
396 * fields will be populated (with |in| and |len| respectively).
397 */
398SCT *o2i_SCT(SCT **psct, const unsigned char **in, size_t len);
399
400/********************
401 * CT log functions *
402 ********************/
403
404/*
405 * Creates a new CT log instance with the given |public_key| and |name|.
406 * Takes ownership of |public_key| but copies |name|.
407 * Returns NULL if malloc fails or if |public_key| cannot be converted to DER.
408 * Should be deleted by the caller using CTLOG_free when no longer needed.
409 */
410CTLOG *CTLOG_new(EVP_PKEY *public_key, const char *name);
411
412/*
413 * Creates a new CTLOG instance with the base64-encoded SubjectPublicKeyInfo DER
414 * in |pkey_base64|. The |name| is a string to help users identify this log.
415 * Returns 1 on success, 0 on failure.
416 * Should be deleted by the caller using CTLOG_free when no longer needed.
417 */
418int CTLOG_new_from_base64(CTLOG ** ct_log,
419 const char *pkey_base64, const char *name);
420
421/*
422 * Deletes a CT log instance and its fields.
423 */
424void CTLOG_free(CTLOG *log);
425
426/* Gets the name of the CT log */
427const char *CTLOG_get0_name(const CTLOG *log);
428/* Gets the ID of the CT log */
429void CTLOG_get0_log_id(const CTLOG *log, const uint8_t **log_id,
430 size_t *log_id_len);
431/* Gets the public key of the CT log */
432EVP_PKEY *CTLOG_get0_public_key(const CTLOG *log);
433
434/**************************
435 * CT log store functions *
436 **************************/
437
438/*
439 * Creates a new CT log store.
440 * Should be deleted by the caller using CTLOG_STORE_free when no longer needed.
441 */
442CTLOG_STORE *CTLOG_STORE_new(void);
443
444/*
445 * Deletes a CT log store and all of the CT log instances held within.
446 */
447void CTLOG_STORE_free(CTLOG_STORE *store);
448
449/*
450 * Finds a CT log in the store based on its log ID.
451 * Returns the CT log, or NULL if no match is found.
452 */
453const CTLOG *CTLOG_STORE_get0_log_by_id(const CTLOG_STORE *store,
454 const uint8_t *log_id,
455 size_t log_id_len);
456
457/*
458 * Loads a CT log list into a |store| from a |file|.
459 * Returns 1 if loading is successful, or 0 otherwise.
460 */
461__owur int CTLOG_STORE_load_file(CTLOG_STORE *store, const char *file);
462
463/*
464 * Loads the default CT log list into a |store|.
465 * See internal/cryptlib.h for the environment variable and file path that are
466 * consulted to find the default file.
467 * Returns 1 if loading is successful, or 0 otherwise.
468 */
469__owur int CTLOG_STORE_load_default_file(CTLOG_STORE *store);
470
471/* BEGIN ERROR CODES */
472/*
473 * The following lines are auto generated by the script mkerr.pl. Any changes
474 * made after this point may be overwritten when the script is next run.
475 */
476
477int ERR_load_CT_strings(void);
478
479/* Error codes for the CT functions. */
480
481/* Function codes. */
482# define CT_F_CTLOG_NEW 117
483# define CT_F_CTLOG_NEW_FROM_BASE64 118
484# define CT_F_CTLOG_NEW_FROM_CONF 119
485# define CT_F_CTLOG_STORE_LOAD_CTX_NEW 122
486# define CT_F_CTLOG_STORE_LOAD_FILE 123
487# define CT_F_CTLOG_STORE_LOAD_LOG 130
488# define CT_F_CTLOG_STORE_NEW 131
489# define CT_F_CT_BASE64_DECODE 124
490# define CT_F_CT_POLICY_EVAL_CTX_NEW 133
491# define CT_F_CT_V1_LOG_ID_FROM_PKEY 125
492# define CT_F_I2O_SCT 107
493# define CT_F_I2O_SCT_LIST 108
494# define CT_F_I2O_SCT_SIGNATURE 109
495# define CT_F_O2I_SCT 110
496# define CT_F_O2I_SCT_LIST 111
497# define CT_F_O2I_SCT_SIGNATURE 112
498# define CT_F_SCT_CTX_NEW 126
499# define CT_F_SCT_CTX_VERIFY 128
500# define CT_F_SCT_NEW 100
501# define CT_F_SCT_NEW_FROM_BASE64 127
502# define CT_F_SCT_SET0_LOG_ID 101
503# define CT_F_SCT_SET1_EXTENSIONS 114
504# define CT_F_SCT_SET1_LOG_ID 115
505# define CT_F_SCT_SET1_SIGNATURE 116
506# define CT_F_SCT_SET_LOG_ENTRY_TYPE 102
507# define CT_F_SCT_SET_SIGNATURE_NID 103
508# define CT_F_SCT_SET_VERSION 104
509
510/* Reason codes. */
511# define CT_R_BASE64_DECODE_ERROR 108
512# define CT_R_INVALID_LOG_ID_LENGTH 100
513# define CT_R_LOG_CONF_INVALID 109
514# define CT_R_LOG_CONF_INVALID_KEY 110
515# define CT_R_LOG_CONF_MISSING_DESCRIPTION 111
516# define CT_R_LOG_CONF_MISSING_KEY 112
517# define CT_R_LOG_KEY_INVALID 113
518# define CT_R_SCT_FUTURE_TIMESTAMP 116
519# define CT_R_SCT_INVALID 104
520# define CT_R_SCT_INVALID_SIGNATURE 107
521# define CT_R_SCT_LIST_INVALID 105
522# define CT_R_SCT_LOG_ID_MISMATCH 114
523# define CT_R_SCT_NOT_SET 106
524# define CT_R_SCT_UNSUPPORTED_VERSION 115
525# define CT_R_UNRECOGNIZED_SIGNATURE_NID 101
526# define CT_R_UNSUPPORTED_ENTRY_TYPE 102
527# define CT_R_UNSUPPORTED_VERSION 103
528
529# ifdef __cplusplus
530}
531# endif
532# endif
533#endif
534