1/*
2 * Copyright 2016-2018 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# include <openssl/cterr.h>
20# ifdef __cplusplus
21extern "C" {
22# endif
23
24
25/* Minimum RSA key size, from RFC6962 */
26# define SCT_MIN_RSA_BITS 2048
27
28/* All hashes are SHA256 in v1 of Certificate Transparency */
29# define CT_V1_HASHLEN SHA256_DIGEST_LENGTH
30
31typedef enum {
32 CT_LOG_ENTRY_TYPE_NOT_SET = -1,
33 CT_LOG_ENTRY_TYPE_X509 = 0,
34 CT_LOG_ENTRY_TYPE_PRECERT = 1
35} ct_log_entry_type_t;
36
37typedef enum {
38 SCT_VERSION_NOT_SET = -1,
39 SCT_VERSION_V1 = 0
40} sct_version_t;
41
42typedef enum {
43 SCT_SOURCE_UNKNOWN,
44 SCT_SOURCE_TLS_EXTENSION,
45 SCT_SOURCE_X509V3_EXTENSION,
46 SCT_SOURCE_OCSP_STAPLED_RESPONSE
47} sct_source_t;
48
49typedef enum {
50 SCT_VALIDATION_STATUS_NOT_SET,
51 SCT_VALIDATION_STATUS_UNKNOWN_LOG,
52 SCT_VALIDATION_STATUS_VALID,
53 SCT_VALIDATION_STATUS_INVALID,
54 SCT_VALIDATION_STATUS_UNVERIFIED,
55 SCT_VALIDATION_STATUS_UNKNOWN_VERSION
56} sct_validation_status_t;
57
58DEFINE_STACK_OF(SCT)
59DEFINE_STACK_OF(CTLOG)
60
61/******************************************
62 * CT policy evaluation context functions *
63 ******************************************/
64
65/*
66 * Creates a new, empty policy evaluation context.
67 * The caller is responsible for calling CT_POLICY_EVAL_CTX_free when finished
68 * with the CT_POLICY_EVAL_CTX.
69 */
70CT_POLICY_EVAL_CTX *CT_POLICY_EVAL_CTX_new(void);
71
72/* Deletes a policy evaluation context and anything it owns. */
73void CT_POLICY_EVAL_CTX_free(CT_POLICY_EVAL_CTX *ctx);
74
75/* Gets the peer certificate that the SCTs are for */
76X509* CT_POLICY_EVAL_CTX_get0_cert(const CT_POLICY_EVAL_CTX *ctx);
77
78/*
79 * Sets the certificate associated with the received SCTs.
80 * Increments the reference count of cert.
81 * Returns 1 on success, 0 otherwise.
82 */
83int CT_POLICY_EVAL_CTX_set1_cert(CT_POLICY_EVAL_CTX *ctx, X509 *cert);
84
85/* Gets the issuer of the aforementioned certificate */
86X509* CT_POLICY_EVAL_CTX_get0_issuer(const CT_POLICY_EVAL_CTX *ctx);
87
88/*
89 * Sets the issuer of the certificate associated with the received SCTs.
90 * Increments the reference count of issuer.
91 * Returns 1 on success, 0 otherwise.
92 */
93int CT_POLICY_EVAL_CTX_set1_issuer(CT_POLICY_EVAL_CTX *ctx, X509 *issuer);
94
95/* Gets the CT logs that are trusted sources of SCTs */
96const CTLOG_STORE *CT_POLICY_EVAL_CTX_get0_log_store(const CT_POLICY_EVAL_CTX *ctx);
97
98/* Sets the log store that is in use. It must outlive the CT_POLICY_EVAL_CTX. */
99void CT_POLICY_EVAL_CTX_set_shared_CTLOG_STORE(CT_POLICY_EVAL_CTX *ctx,
100 CTLOG_STORE *log_store);
101
102/*
103 * Gets the time, in milliseconds since the Unix epoch, that will be used as the
104 * current time when checking whether an SCT was issued in the future.
105 * Such SCTs will fail validation, as required by RFC6962.
106 */
107uint64_t CT_POLICY_EVAL_CTX_get_time(const CT_POLICY_EVAL_CTX *ctx);
108
109/*
110 * Sets the time to evaluate SCTs against, in milliseconds since the Unix epoch.
111 * If an SCT's timestamp is after this time, it will be interpreted as having
112 * been issued in the future. RFC6962 states that "TLS clients MUST reject SCTs
113 * whose timestamp is in the future", so an SCT will not validate in this case.
114 */
115void CT_POLICY_EVAL_CTX_set_time(CT_POLICY_EVAL_CTX *ctx, uint64_t time_in_ms);
116
117/*****************
118 * SCT functions *
119 *****************/
120
121/*
122 * Creates a new, blank SCT.
123 * The caller is responsible for calling SCT_free when finished with the SCT.
124 */
125SCT *SCT_new(void);
126
127/*
128 * Creates a new SCT from some base64-encoded strings.
129 * The caller is responsible for calling SCT_free when finished with the SCT.
130 */
131SCT *SCT_new_from_base64(unsigned char version,
132 const char *logid_base64,
133 ct_log_entry_type_t entry_type,
134 uint64_t timestamp,
135 const char *extensions_base64,
136 const char *signature_base64);
137
138/*
139 * Frees the SCT and the underlying data structures.
140 */
141void SCT_free(SCT *sct);
142
143/*
144 * Free a stack of SCTs, and the underlying SCTs themselves.
145 * Intended to be compatible with X509V3_EXT_FREE.
146 */
147void SCT_LIST_free(STACK_OF(SCT) *a);
148
149/*
150 * Returns the version of the SCT.
151 */
152sct_version_t SCT_get_version(const SCT *sct);
153
154/*
155 * Set the version of an SCT.
156 * Returns 1 on success, 0 if the version is unrecognized.
157 */
158__owur int SCT_set_version(SCT *sct, sct_version_t version);
159
160/*
161 * Returns the log entry type of the SCT.
162 */
163ct_log_entry_type_t SCT_get_log_entry_type(const SCT *sct);
164
165/*
166 * Set the log entry type of an SCT.
167 * Returns 1 on success, 0 otherwise.
168 */
169__owur int SCT_set_log_entry_type(SCT *sct, ct_log_entry_type_t entry_type);
170
171/*
172 * Gets the ID of the log that an SCT came from.
173 * Ownership of the log ID remains with the SCT.
174 * Returns the length of the log ID.
175 */
176size_t SCT_get0_log_id(const SCT *sct, unsigned char **log_id);
177
178/*
179 * Set the log ID of an SCT to point directly to the *log_id specified.
180 * The SCT takes ownership of the specified pointer.
181 * Returns 1 on success, 0 otherwise.
182 */
183__owur int SCT_set0_log_id(SCT *sct, unsigned char *log_id, size_t log_id_len);
184
185/*
186 * Set the log ID of an SCT.
187 * This makes a copy of the log_id.
188 * Returns 1 on success, 0 otherwise.
189 */
190__owur int SCT_set1_log_id(SCT *sct, const unsigned char *log_id,
191 size_t log_id_len);
192
193/*
194 * Returns the timestamp for the SCT (epoch time in milliseconds).
195 */
196uint64_t SCT_get_timestamp(const SCT *sct);
197
198/*
199 * Set the timestamp of an SCT (epoch time in milliseconds).
200 */
201void SCT_set_timestamp(SCT *sct, uint64_t timestamp);
202
203/*
204 * Return the NID for the signature used by the SCT.
205 * For CT v1, this will be either NID_sha256WithRSAEncryption or
206 * NID_ecdsa_with_SHA256 (or NID_undef if incorrect/unset).
207 */
208int SCT_get_signature_nid(const SCT *sct);
209
210/*
211 * Set the signature type of an SCT
212 * For CT v1, this should be either NID_sha256WithRSAEncryption or
213 * NID_ecdsa_with_SHA256.
214 * Returns 1 on success, 0 otherwise.
215 */
216__owur int SCT_set_signature_nid(SCT *sct, int nid);
217
218/*
219 * Set *ext to point to the extension data for the SCT. ext must not be NULL.
220 * The SCT retains ownership of this pointer.
221 * Returns length of the data pointed to.
222 */
223size_t SCT_get0_extensions(const SCT *sct, unsigned char **ext);
224
225/*
226 * Set the extensions of an SCT to point directly to the *ext specified.
227 * The SCT takes ownership of the specified pointer.
228 */
229void SCT_set0_extensions(SCT *sct, unsigned char *ext, size_t ext_len);
230
231/*
232 * Set the extensions of an SCT.
233 * This takes a copy of the ext.
234 * Returns 1 on success, 0 otherwise.
235 */
236__owur int SCT_set1_extensions(SCT *sct, const unsigned char *ext,
237 size_t ext_len);
238
239/*
240 * Set *sig to point to the signature for the SCT. sig must not be NULL.
241 * The SCT retains ownership of this pointer.
242 * Returns length of the data pointed to.
243 */
244size_t SCT_get0_signature(const SCT *sct, unsigned char **sig);
245
246/*
247 * Set the signature of an SCT to point directly to the *sig specified.
248 * The SCT takes ownership of the specified pointer.
249 */
250void SCT_set0_signature(SCT *sct, unsigned char *sig, size_t sig_len);
251
252/*
253 * Set the signature of an SCT to be a copy of the *sig specified.
254 * Returns 1 on success, 0 otherwise.
255 */
256__owur int SCT_set1_signature(SCT *sct, const unsigned char *sig,
257 size_t sig_len);
258
259/*
260 * The origin of this SCT, e.g. TLS extension, OCSP response, etc.
261 */
262sct_source_t SCT_get_source(const SCT *sct);
263
264/*
265 * Set the origin of this SCT, e.g. TLS extension, OCSP response, etc.
266 * Returns 1 on success, 0 otherwise.
267 */
268__owur int SCT_set_source(SCT *sct, sct_source_t source);
269
270/*
271 * Returns a text string describing the validation status of |sct|.
272 */
273const char *SCT_validation_status_string(const SCT *sct);
274
275/*
276 * Pretty-prints an |sct| to |out|.
277 * It will be indented by the number of spaces specified by |indent|.
278 * If |logs| is not NULL, it will be used to lookup the CT log that the SCT came
279 * from, so that the log name can be printed.
280 */
281void SCT_print(const SCT *sct, BIO *out, int indent, const CTLOG_STORE *logs);
282
283/*
284 * Pretty-prints an |sct_list| to |out|.
285 * It will be indented by the number of spaces specified by |indent|.
286 * SCTs will be delimited by |separator|.
287 * If |logs| is not NULL, it will be used to lookup the CT log that each SCT
288 * came from, so that the log names can be printed.
289 */
290void SCT_LIST_print(const STACK_OF(SCT) *sct_list, BIO *out, int indent,
291 const char *separator, const CTLOG_STORE *logs);
292
293/*
294 * Gets the last result of validating this SCT.
295 * If it has not been validated yet, returns SCT_VALIDATION_STATUS_NOT_SET.
296 */
297sct_validation_status_t SCT_get_validation_status(const SCT *sct);
298
299/*
300 * Validates the given SCT with the provided context.
301 * Sets the "validation_status" field of the SCT.
302 * Returns 1 if the SCT is valid and the signature verifies.
303 * Returns 0 if the SCT is invalid or could not be verified.
304 * Returns -1 if an error occurs.
305 */
306__owur int SCT_validate(SCT *sct, const CT_POLICY_EVAL_CTX *ctx);
307
308/*
309 * Validates the given list of SCTs with the provided context.
310 * Sets the "validation_status" field of each SCT.
311 * Returns 1 if there are no invalid SCTs and all signatures verify.
312 * Returns 0 if at least one SCT is invalid or could not be verified.
313 * Returns a negative integer if an error occurs.
314 */
315__owur int SCT_LIST_validate(const STACK_OF(SCT) *scts,
316 CT_POLICY_EVAL_CTX *ctx);
317
318
319/*********************************
320 * SCT parsing and serialisation *
321 *********************************/
322
323/*
324 * Serialize (to TLS format) a stack of SCTs and return the length.
325 * "a" must not be NULL.
326 * If "pp" is NULL, just return the length of what would have been serialized.
327 * If "pp" is not NULL and "*pp" is null, function will allocate a new pointer
328 * for data that caller is responsible for freeing (only if function returns
329 * successfully).
330 * If "pp" is NULL and "*pp" is not NULL, caller is responsible for ensuring
331 * that "*pp" is large enough to accept all of the serialized data.
332 * Returns < 0 on error, >= 0 indicating bytes written (or would have been)
333 * on success.
334 */
335__owur int i2o_SCT_LIST(const STACK_OF(SCT) *a, unsigned char **pp);
336
337/*
338 * Convert TLS format SCT list to a stack of SCTs.
339 * If "a" or "*a" is NULL, a new stack will be created that the caller is
340 * responsible for freeing (by calling SCT_LIST_free).
341 * "**pp" and "*pp" must not be NULL.
342 * Upon success, "*pp" will point to after the last bytes read, and a stack
343 * will be returned.
344 * Upon failure, a NULL pointer will be returned, and the position of "*pp" is
345 * not defined.
346 */
347STACK_OF(SCT) *o2i_SCT_LIST(STACK_OF(SCT) **a, const unsigned char **pp,
348 size_t len);
349
350/*
351 * Serialize (to DER format) a stack of SCTs and return the length.
352 * "a" must not be NULL.
353 * If "pp" is NULL, just returns the length of what would have been serialized.
354 * If "pp" is not NULL and "*pp" is null, function will allocate a new pointer
355 * for data that caller is responsible for freeing (only if function returns
356 * successfully).
357 * If "pp" is NULL and "*pp" is not NULL, caller is responsible for ensuring
358 * that "*pp" is large enough to accept all of the serialized data.
359 * Returns < 0 on error, >= 0 indicating bytes written (or would have been)
360 * on success.
361 */
362__owur int i2d_SCT_LIST(const STACK_OF(SCT) *a, unsigned char **pp);
363
364/*
365 * Parses an SCT list in DER format and returns it.
366 * If "a" or "*a" is NULL, a new stack will be created that the caller is
367 * responsible for freeing (by calling SCT_LIST_free).
368 * "**pp" and "*pp" must not be NULL.
369 * Upon success, "*pp" will point to after the last bytes read, and a stack
370 * will be returned.
371 * Upon failure, a NULL pointer will be returned, and the position of "*pp" is
372 * not defined.
373 */
374STACK_OF(SCT) *d2i_SCT_LIST(STACK_OF(SCT) **a, const unsigned char **pp,
375 long len);
376
377/*
378 * Serialize (to TLS format) an |sct| and write it to |out|.
379 * If |out| is null, no SCT will be output but the length will still be returned.
380 * If |out| points to a null pointer, a string will be allocated to hold the
381 * TLS-format SCT. It is the responsibility of the caller to free it.
382 * If |out| points to an allocated string, the TLS-format SCT will be written
383 * to it.
384 * The length of the SCT in TLS format will be returned.
385 */
386__owur int i2o_SCT(const SCT *sct, unsigned char **out);
387
388/*
389 * Parses an SCT in TLS format and returns it.
390 * If |psct| is not null, it will end up pointing to the parsed SCT. If it
391 * already points to a non-null pointer, the pointer will be free'd.
392 * |in| should be a pointer to a string containing the TLS-format SCT.
393 * |in| will be advanced to the end of the SCT if parsing succeeds.
394 * |len| should be the length of the SCT in |in|.
395 * Returns NULL if an error occurs.
396 * If the SCT is an unsupported version, only the SCT's 'sct' and 'sct_len'
397 * fields will be populated (with |in| and |len| respectively).
398 */
399SCT *o2i_SCT(SCT **psct, const unsigned char **in, size_t len);
400
401/********************
402 * CT log functions *
403 ********************/
404
405/*
406 * Creates a new CT log instance with the given |public_key| and |name|.
407 * Takes ownership of |public_key| but copies |name|.
408 * Returns NULL if malloc fails or if |public_key| cannot be converted to DER.
409 * Should be deleted by the caller using CTLOG_free when no longer needed.
410 */
411CTLOG *CTLOG_new(EVP_PKEY *public_key, const char *name);
412
413/*
414 * Creates a new CTLOG instance with the base64-encoded SubjectPublicKeyInfo DER
415 * in |pkey_base64|. The |name| is a string to help users identify this log.
416 * Returns 1 on success, 0 on failure.
417 * Should be deleted by the caller using CTLOG_free when no longer needed.
418 */
419int CTLOG_new_from_base64(CTLOG ** ct_log,
420 const char *pkey_base64, const char *name);
421
422/*
423 * Deletes a CT log instance and its fields.
424 */
425void CTLOG_free(CTLOG *log);
426
427/* Gets the name of the CT log */
428const char *CTLOG_get0_name(const CTLOG *log);
429/* Gets the ID of the CT log */
430void CTLOG_get0_log_id(const CTLOG *log, const uint8_t **log_id,
431 size_t *log_id_len);
432/* Gets the public key of the CT log */
433EVP_PKEY *CTLOG_get0_public_key(const CTLOG *log);
434
435/**************************
436 * CT log store functions *
437 **************************/
438
439/*
440 * Creates a new CT log store.
441 * Should be deleted by the caller using CTLOG_STORE_free when no longer needed.
442 */
443CTLOG_STORE *CTLOG_STORE_new(void);
444
445/*
446 * Deletes a CT log store and all of the CT log instances held within.
447 */
448void CTLOG_STORE_free(CTLOG_STORE *store);
449
450/*
451 * Finds a CT log in the store based on its log ID.
452 * Returns the CT log, or NULL if no match is found.
453 */
454const CTLOG *CTLOG_STORE_get0_log_by_id(const CTLOG_STORE *store,
455 const uint8_t *log_id,
456 size_t log_id_len);
457
458/*
459 * Loads a CT log list into a |store| from a |file|.
460 * Returns 1 if loading is successful, or 0 otherwise.
461 */
462__owur int CTLOG_STORE_load_file(CTLOG_STORE *store, const char *file);
463
464/*
465 * Loads the default CT log list into a |store|.
466 * See internal/cryptlib.h for the environment variable and file path that are
467 * consulted to find the default file.
468 * Returns 1 if loading is successful, or 0 otherwise.
469 */
470__owur int CTLOG_STORE_load_default_file(CTLOG_STORE *store);
471
472# ifdef __cplusplus
473}
474# endif
475# endif
476#endif
477