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 21 extern "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 31 typedef 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 37 typedef enum { 38 SCT_VERSION_NOT_SET = -1, 39 SCT_VERSION_V1 = 0 40 } sct_version_t; 41 42 typedef 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 49 typedef 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 58 DEFINE_STACK_OF(SCT) 59 DEFINE_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 */ 70 CT_POLICY_EVAL_CTX *CT_POLICY_EVAL_CTX_new(void); 71 72 /* Deletes a policy evaluation context and anything it owns. */ 73 void CT_POLICY_EVAL_CTX_free(CT_POLICY_EVAL_CTX *ctx); 74 75 /* Gets the peer certificate that the SCTs are for */ 76 X509* 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 */ 83 int CT_POLICY_EVAL_CTX_set1_cert(CT_POLICY_EVAL_CTX *ctx, X509 *cert); 84 85 /* Gets the issuer of the aforementioned certificate */ 86 X509* 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 */ 93 int 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 */ 96 const 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. */ 99 void 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 */ 107 uint64_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 */ 115 void 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 */ 125 SCT *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 */ 131 SCT *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 */ 141 void 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 */ 147 void SCT_LIST_free(STACK_OF(SCT) *a); 148 149 /* 150 * Returns the version of the SCT. 151 */ 152 sct_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 */ 163 ct_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 */ 176 size_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 */ 196 uint64_t SCT_get_timestamp(const SCT *sct); 197 198 /* 199 * Set the timestamp of an SCT (epoch time in milliseconds). 200 */ 201 void 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 */ 208 int 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 */ 223 size_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 */ 229 void 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 */ 244 size_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 */ 250 void 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 */ 262 sct_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 */ 273 const 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 */ 281 void 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 */ 290 void 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 */ 297 sct_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 */ 347 STACK_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 */ 374 STACK_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 */ 399 SCT *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 */ 411 CTLOG *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 */ 419 int 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 */ 425 void CTLOG_free(CTLOG *log); 426 427 /* Gets the name of the CT log */ 428 const char *CTLOG_get0_name(const CTLOG *log); 429 /* Gets the ID of the CT log */ 430 void 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 */ 433 EVP_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 */ 443 CTLOG_STORE *CTLOG_STORE_new(void); 444 445 /* 446 * Deletes a CT log store and all of the CT log instances held within. 447 */ 448 void 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 */ 454 const 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 * Returns 1 if loading is successful, or 0 otherwise. 467 */ 468 __owur int CTLOG_STORE_load_default_file(CTLOG_STORE *store); 469 470 # ifdef __cplusplus 471 } 472 # endif 473 # endif 474 #endif 475