1/*
2 * Copyright 2016-2018 The OpenSSL Project Authors. All Rights Reserved.
3 *
4 * Licensed under the Apache License 2.0 (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 OPENSSL_CT_H
11# define OPENSSL_CT_H
12# pragma once
13
14# include <openssl/macros.h>
15# ifndef OPENSSL_NO_DEPRECATED_3_0
16# define HEADER_CT_H
17# endif
18
19# include <openssl/opensslconf.h>
20
21# ifndef OPENSSL_NO_CT
22# include <openssl/types.h>
23# include <openssl/safestack.h>
24# include <openssl/x509.h>
25# include <openssl/cterr.h>
26# ifdef __cplusplus
27extern "C" {
28# endif
29
30
31/* Minimum RSA key size, from RFC6962 */
32# define SCT_MIN_RSA_BITS 2048
33
34/* All hashes are SHA256 in v1 of Certificate Transparency */
35# define CT_V1_HASHLEN SHA256_DIGEST_LENGTH
36
37typedef enum {
38 CT_LOG_ENTRY_TYPE_NOT_SET = -1,
39 CT_LOG_ENTRY_TYPE_X509 = 0,
40 CT_LOG_ENTRY_TYPE_PRECERT = 1
41} ct_log_entry_type_t;
42
43typedef enum {
44 SCT_VERSION_NOT_SET = -1,
45 SCT_VERSION_V1 = 0
46} sct_version_t;
47
48typedef enum {
49 SCT_SOURCE_UNKNOWN,
50 SCT_SOURCE_TLS_EXTENSION,
51 SCT_SOURCE_X509V3_EXTENSION,
52 SCT_SOURCE_OCSP_STAPLED_RESPONSE
53} sct_source_t;
54
55typedef enum {
56 SCT_VALIDATION_STATUS_NOT_SET,
57 SCT_VALIDATION_STATUS_UNKNOWN_LOG,
58 SCT_VALIDATION_STATUS_VALID,
59 SCT_VALIDATION_STATUS_INVALID,
60 SCT_VALIDATION_STATUS_UNVERIFIED,
61 SCT_VALIDATION_STATUS_UNKNOWN_VERSION
62} sct_validation_status_t;
63
64DEFINE_STACK_OF(SCT)
65DEFINE_STACK_OF(CTLOG)
66
67/******************************************
68 * CT policy evaluation context functions *
69 ******************************************/
70
71/*
72 * Creates a new, empty policy evaluation context.
73 * The caller is responsible for calling CT_POLICY_EVAL_CTX_free when finished
74 * with the CT_POLICY_EVAL_CTX.
75 */
76CT_POLICY_EVAL_CTX *CT_POLICY_EVAL_CTX_new(void);
77
78/* Deletes a policy evaluation context and anything it owns. */
79void CT_POLICY_EVAL_CTX_free(CT_POLICY_EVAL_CTX *ctx);
80
81/* Gets the peer certificate that the SCTs are for */
82X509* CT_POLICY_EVAL_CTX_get0_cert(const CT_POLICY_EVAL_CTX *ctx);
83
84/*
85 * Sets the certificate associated with the received SCTs.
86 * Increments the reference count of cert.
87 * Returns 1 on success, 0 otherwise.
88 */
89int CT_POLICY_EVAL_CTX_set1_cert(CT_POLICY_EVAL_CTX *ctx, X509 *cert);
90
91/* Gets the issuer of the aforementioned certificate */
92X509* CT_POLICY_EVAL_CTX_get0_issuer(const CT_POLICY_EVAL_CTX *ctx);
93
94/*
95 * Sets the issuer of the certificate associated with the received SCTs.
96 * Increments the reference count of issuer.
97 * Returns 1 on success, 0 otherwise.
98 */
99int CT_POLICY_EVAL_CTX_set1_issuer(CT_POLICY_EVAL_CTX *ctx, X509 *issuer);
100
101/* Gets the CT logs that are trusted sources of SCTs */
102const CTLOG_STORE *CT_POLICY_EVAL_CTX_get0_log_store(const CT_POLICY_EVAL_CTX *ctx);
103
104/* Sets the log store that is in use. It must outlive the CT_POLICY_EVAL_CTX. */
105void CT_POLICY_EVAL_CTX_set_shared_CTLOG_STORE(CT_POLICY_EVAL_CTX *ctx,
106 CTLOG_STORE *log_store);
107
108/*
109 * Gets the time, in milliseconds since the Unix epoch, that will be used as the
110 * current time when checking whether an SCT was issued in the future.
111 * Such SCTs will fail validation, as required by RFC6962.
112 */
113uint64_t CT_POLICY_EVAL_CTX_get_time(const CT_POLICY_EVAL_CTX *ctx);
114
115/*
116 * Sets the time to evaluate SCTs against, in milliseconds since the Unix epoch.
117 * If an SCT's timestamp is after this time, it will be interpreted as having
118 * been issued in the future. RFC6962 states that "TLS clients MUST reject SCTs
119 * whose timestamp is in the future", so an SCT will not validate in this case.
120 */
121void CT_POLICY_EVAL_CTX_set_time(CT_POLICY_EVAL_CTX *ctx, uint64_t time_in_ms);
122
123/*****************
124 * SCT functions *
125 *****************/
126
127/*
128 * Creates a new, blank SCT.
129 * The caller is responsible for calling SCT_free when finished with the SCT.
130 */
131SCT *SCT_new(void);
132
133/*
134 * Creates a new SCT from some base64-encoded strings.
135 * The caller is responsible for calling SCT_free when finished with the SCT.
136 */
137SCT *SCT_new_from_base64(unsigned char version,
138 const char *logid_base64,
139 ct_log_entry_type_t entry_type,
140 uint64_t timestamp,
141 const char *extensions_base64,
142 const char *signature_base64);
143
144/*
145 * Frees the SCT and the underlying data structures.
146 */
147void SCT_free(SCT *sct);
148
149/*
150 * Free a stack of SCTs, and the underlying SCTs themselves.
151 * Intended to be compatible with X509V3_EXT_FREE.
152 */
153void SCT_LIST_free(STACK_OF(SCT) *a);
154
155/*
156 * Returns the version of the SCT.
157 */
158sct_version_t SCT_get_version(const SCT *sct);
159
160/*
161 * Set the version of an SCT.
162 * Returns 1 on success, 0 if the version is unrecognized.
163 */
164__owur int SCT_set_version(SCT *sct, sct_version_t version);
165
166/*
167 * Returns the log entry type of the SCT.
168 */
169ct_log_entry_type_t SCT_get_log_entry_type(const SCT *sct);
170
171/*
172 * Set the log entry type of an SCT.
173 * Returns 1 on success, 0 otherwise.
174 */
175__owur int SCT_set_log_entry_type(SCT *sct, ct_log_entry_type_t entry_type);
176
177/*
178 * Gets the ID of the log that an SCT came from.
179 * Ownership of the log ID remains with the SCT.
180 * Returns the length of the log ID.
181 */
182size_t SCT_get0_log_id(const SCT *sct, unsigned char **log_id);
183
184/*
185 * Set the log ID of an SCT to point directly to the *log_id specified.
186 * The SCT takes ownership of the specified pointer.
187 * Returns 1 on success, 0 otherwise.
188 */
189__owur int SCT_set0_log_id(SCT *sct, unsigned char *log_id, size_t log_id_len);
190
191/*
192 * Set the log ID of an SCT.
193 * This makes a copy of the log_id.
194 * Returns 1 on success, 0 otherwise.
195 */
196__owur int SCT_set1_log_id(SCT *sct, const unsigned char *log_id,
197 size_t log_id_len);
198
199/*
200 * Returns the timestamp for the SCT (epoch time in milliseconds).
201 */
202uint64_t SCT_get_timestamp(const SCT *sct);
203
204/*
205 * Set the timestamp of an SCT (epoch time in milliseconds).
206 */
207void SCT_set_timestamp(SCT *sct, uint64_t timestamp);
208
209/*
210 * Return the NID for the signature used by the SCT.
211 * For CT v1, this will be either NID_sha256WithRSAEncryption or
212 * NID_ecdsa_with_SHA256 (or NID_undef if incorrect/unset).
213 */
214int SCT_get_signature_nid(const SCT *sct);
215
216/*
217 * Set the signature type of an SCT
218 * For CT v1, this should be either NID_sha256WithRSAEncryption or
219 * NID_ecdsa_with_SHA256.
220 * Returns 1 on success, 0 otherwise.
221 */
222__owur int SCT_set_signature_nid(SCT *sct, int nid);
223
224/*
225 * Set *ext to point to the extension data for the SCT. ext must not be NULL.
226 * The SCT retains ownership of this pointer.
227 * Returns length of the data pointed to.
228 */
229size_t SCT_get0_extensions(const SCT *sct, unsigned char **ext);
230
231/*
232 * Set the extensions of an SCT to point directly to the *ext specified.
233 * The SCT takes ownership of the specified pointer.
234 */
235void SCT_set0_extensions(SCT *sct, unsigned char *ext, size_t ext_len);
236
237/*
238 * Set the extensions of an SCT.
239 * This takes a copy of the ext.
240 * Returns 1 on success, 0 otherwise.
241 */
242__owur int SCT_set1_extensions(SCT *sct, const unsigned char *ext,
243 size_t ext_len);
244
245/*
246 * Set *sig to point to the signature for the SCT. sig must not be NULL.
247 * The SCT retains ownership of this pointer.
248 * Returns length of the data pointed to.
249 */
250size_t SCT_get0_signature(const SCT *sct, unsigned char **sig);
251
252/*
253 * Set the signature of an SCT to point directly to the *sig specified.
254 * The SCT takes ownership of the specified pointer.
255 */
256void SCT_set0_signature(SCT *sct, unsigned char *sig, size_t sig_len);
257
258/*
259 * Set the signature of an SCT to be a copy of the *sig specified.
260 * Returns 1 on success, 0 otherwise.
261 */
262__owur int SCT_set1_signature(SCT *sct, const unsigned char *sig,
263 size_t sig_len);
264
265/*
266 * The origin of this SCT, e.g. TLS extension, OCSP response, etc.
267 */
268sct_source_t SCT_get_source(const SCT *sct);
269
270/*
271 * Set the origin of this SCT, e.g. TLS extension, OCSP response, etc.
272 * Returns 1 on success, 0 otherwise.
273 */
274__owur int SCT_set_source(SCT *sct, sct_source_t source);
275
276/*
277 * Returns a text string describing the validation status of |sct|.
278 */
279const char *SCT_validation_status_string(const SCT *sct);
280
281/*
282 * Pretty-prints an |sct| to |out|.
283 * It will be indented by the number of spaces specified by |indent|.
284 * If |logs| is not NULL, it will be used to lookup the CT log that the SCT came
285 * from, so that the log name can be printed.
286 */
287void SCT_print(const SCT *sct, BIO *out, int indent, const CTLOG_STORE *logs);
288
289/*
290 * Pretty-prints an |sct_list| to |out|.
291 * It will be indented by the number of spaces specified by |indent|.
292 * SCTs will be delimited by |separator|.
293 * If |logs| is not NULL, it will be used to lookup the CT log that each SCT
294 * came from, so that the log names can be printed.
295 */
296void SCT_LIST_print(const STACK_OF(SCT) *sct_list, BIO *out, int indent,
297 const char *separator, const CTLOG_STORE *logs);
298
299/*
300 * Gets the last result of validating this SCT.
301 * If it has not been validated yet, returns SCT_VALIDATION_STATUS_NOT_SET.
302 */
303sct_validation_status_t SCT_get_validation_status(const SCT *sct);
304
305/*
306 * Validates the given SCT with the provided context.
307 * Sets the "validation_status" field of the SCT.
308 * Returns 1 if the SCT is valid and the signature verifies.
309 * Returns 0 if the SCT is invalid or could not be verified.
310 * Returns -1 if an error occurs.
311 */
312__owur int SCT_validate(SCT *sct, const CT_POLICY_EVAL_CTX *ctx);
313
314/*
315 * Validates the given list of SCTs with the provided context.
316 * Sets the "validation_status" field of each SCT.
317 * Returns 1 if there are no invalid SCTs and all signatures verify.
318 * Returns 0 if at least one SCT is invalid or could not be verified.
319 * Returns a negative integer if an error occurs.
320 */
321__owur int SCT_LIST_validate(const STACK_OF(SCT) *scts,
322 CT_POLICY_EVAL_CTX *ctx);
323
324
325/*********************************
326 * SCT parsing and serialisation *
327 *********************************/
328
329/*
330 * Serialize (to TLS format) a stack of SCTs and return the length.
331 * "a" must not be NULL.
332 * If "pp" is NULL, just return the length of what would have been serialized.
333 * If "pp" is not NULL and "*pp" is null, function will allocate a new pointer
334 * for data that caller is responsible for freeing (only if function returns
335 * successfully).
336 * If "pp" is NULL and "*pp" is not NULL, caller is responsible for ensuring
337 * that "*pp" is large enough to accept all of the serialized data.
338 * Returns < 0 on error, >= 0 indicating bytes written (or would have been)
339 * on success.
340 */
341__owur int i2o_SCT_LIST(const STACK_OF(SCT) *a, unsigned char **pp);
342
343/*
344 * Convert TLS format SCT list to a stack of SCTs.
345 * If "a" or "*a" is NULL, a new stack will be created that the caller is
346 * responsible for freeing (by calling SCT_LIST_free).
347 * "**pp" and "*pp" must not be NULL.
348 * Upon success, "*pp" will point to after the last bytes read, and a stack
349 * will be returned.
350 * Upon failure, a NULL pointer will be returned, and the position of "*pp" is
351 * not defined.
352 */
353STACK_OF(SCT) *o2i_SCT_LIST(STACK_OF(SCT) **a, const unsigned char **pp,
354 size_t len);
355
356/*
357 * Serialize (to DER format) a stack of SCTs and return the length.
358 * "a" must not be NULL.
359 * If "pp" is NULL, just returns the length of what would have been serialized.
360 * If "pp" is not NULL and "*pp" is null, function will allocate a new pointer
361 * for data that caller is responsible for freeing (only if function returns
362 * successfully).
363 * If "pp" is NULL and "*pp" is not NULL, caller is responsible for ensuring
364 * that "*pp" is large enough to accept all of the serialized data.
365 * Returns < 0 on error, >= 0 indicating bytes written (or would have been)
366 * on success.
367 */
368__owur int i2d_SCT_LIST(const STACK_OF(SCT) *a, unsigned char **pp);
369
370/*
371 * Parses an SCT list in DER format and returns it.
372 * If "a" or "*a" is NULL, a new stack will be created that the caller is
373 * responsible for freeing (by calling SCT_LIST_free).
374 * "**pp" and "*pp" must not be NULL.
375 * Upon success, "*pp" will point to after the last bytes read, and a stack
376 * will be returned.
377 * Upon failure, a NULL pointer will be returned, and the position of "*pp" is
378 * not defined.
379 */
380STACK_OF(SCT) *d2i_SCT_LIST(STACK_OF(SCT) **a, const unsigned char **pp,
381 long len);
382
383/*
384 * Serialize (to TLS format) an |sct| and write it to |out|.
385 * If |out| is null, no SCT will be output but the length will still be returned.
386 * If |out| points to a null pointer, a string will be allocated to hold the
387 * TLS-format SCT. It is the responsibility of the caller to free it.
388 * If |out| points to an allocated string, the TLS-format SCT will be written
389 * to it.
390 * The length of the SCT in TLS format will be returned.
391 */
392__owur int i2o_SCT(const SCT *sct, unsigned char **out);
393
394/*
395 * Parses an SCT in TLS format and returns it.
396 * If |psct| is not null, it will end up pointing to the parsed SCT. If it
397 * already points to a non-null pointer, the pointer will be free'd.
398 * |in| should be a pointer to a string containing the TLS-format SCT.
399 * |in| will be advanced to the end of the SCT if parsing succeeds.
400 * |len| should be the length of the SCT in |in|.
401 * Returns NULL if an error occurs.
402 * If the SCT is an unsupported version, only the SCT's 'sct' and 'sct_len'
403 * fields will be populated (with |in| and |len| respectively).
404 */
405SCT *o2i_SCT(SCT **psct, const unsigned char **in, size_t len);
406
407/********************
408 * CT log functions *
409 ********************/
410
411/*
412 * Creates a new CT log instance with the given |public_key| and |name|.
413 * Takes ownership of |public_key| but copies |name|.
414 * Returns NULL if malloc fails or if |public_key| cannot be converted to DER.
415 * Should be deleted by the caller using CTLOG_free when no longer needed.
416 */
417CTLOG *CTLOG_new(EVP_PKEY *public_key, const char *name);
418
419/*
420 * Creates a new CTLOG instance with the base64-encoded SubjectPublicKeyInfo DER
421 * in |pkey_base64|. The |name| is a string to help users identify this log.
422 * Returns 1 on success, 0 on failure.
423 * Should be deleted by the caller using CTLOG_free when no longer needed.
424 */
425int CTLOG_new_from_base64(CTLOG ** ct_log,
426 const char *pkey_base64, const char *name);
427
428/*
429 * Deletes a CT log instance and its fields.
430 */
431void CTLOG_free(CTLOG *log);
432
433/* Gets the name of the CT log */
434const char *CTLOG_get0_name(const CTLOG *log);
435/* Gets the ID of the CT log */
436void CTLOG_get0_log_id(const CTLOG *log, const uint8_t **log_id,
437 size_t *log_id_len);
438/* Gets the public key of the CT log */
439EVP_PKEY *CTLOG_get0_public_key(const CTLOG *log);
440
441/**************************
442 * CT log store functions *
443 **************************/
444
445/*
446 * Creates a new CT log store.
447 * Should be deleted by the caller using CTLOG_STORE_free when no longer needed.
448 */
449CTLOG_STORE *CTLOG_STORE_new(void);
450
451/*
452 * Deletes a CT log store and all of the CT log instances held within.
453 */
454void CTLOG_STORE_free(CTLOG_STORE *store);
455
456/*
457 * Finds a CT log in the store based on its log ID.
458 * Returns the CT log, or NULL if no match is found.
459 */
460const CTLOG *CTLOG_STORE_get0_log_by_id(const CTLOG_STORE *store,
461 const uint8_t *log_id,
462 size_t log_id_len);
463
464/*
465 * Loads a CT log list into a |store| from a |file|.
466 * Returns 1 if loading is successful, or 0 otherwise.
467 */
468__owur int CTLOG_STORE_load_file(CTLOG_STORE *store, const char *file);
469
470/*
471 * Loads the default CT log list into a |store|.
472 * Returns 1 if loading is successful, or 0 otherwise.
473 */
474__owur int CTLOG_STORE_load_default_file(CTLOG_STORE *store);
475
476# ifdef __cplusplus
477}
478# endif
479# endif
480#endif
481