include/openssl/ct.h

   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
  27 extern "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
  37 typedef 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
  43 typedef enum {
  44     SCT_VERSION_NOT_SET = -1,
  45     SCT_VERSION_V1 = 0
  46 } sct_version_t;
  47
  48 typedef 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
  55 typedef 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
  64 DEFINE_STACK_OF(SCT)
  65 DEFINE_STACK_OF(CTLOG)
  66
  67 /******************************************
  68  * CT policy evaluation context functions *
  69  ******************************************/
  70
  71 /*
  72  * Creates a new, empty policy evaluation context associated with the given
  73  * library context and property query string.
  74  * The caller is responsible for calling CT_POLICY_EVAL_CTX_free when finished
  75  * with the CT_POLICY_EVAL_CTX.
  76  */
  77 CT_POLICY_EVAL_CTX *CT_POLICY_EVAL_CTX_new_with_libctx(OPENSSL_CTX *libctx,
  78                                                        const char *propq);
  79
  80 /*
  81  * The same as CT_POLICY_EVAL_CTX_new_with_libctx() but the default library
  82  * context and property query string is used.
  83  */
  84 CT_POLICY_EVAL_CTX *CT_POLICY_EVAL_CTX_new(void);
  85
  86 /* Deletes a policy evaluation context and anything it owns. */
  87 void CT_POLICY_EVAL_CTX_free(CT_POLICY_EVAL_CTX *ctx);
  88
  89 /* Gets the peer certificate that the SCTs are for */
  90 X509* CT_POLICY_EVAL_CTX_get0_cert(const CT_POLICY_EVAL_CTX *ctx);
  91
  92 /*
  93  * Sets the certificate associated with the received SCTs.
  94  * Increments the reference count of cert.
  95  * Returns 1 on success, 0 otherwise.
  96  */
  97 int CT_POLICY_EVAL_CTX_set1_cert(CT_POLICY_EVAL_CTX *ctx, X509 *cert);
  98
  99 /* Gets the issuer of the aforementioned certificate */
 100 X509* CT_POLICY_EVAL_CTX_get0_issuer(const CT_POLICY_EVAL_CTX *ctx);
 101
 102 /*
 103  * Sets the issuer of the certificate associated with the received SCTs.
 104  * Increments the reference count of issuer.
 105  * Returns 1 on success, 0 otherwise.
 106  */
 107 int CT_POLICY_EVAL_CTX_set1_issuer(CT_POLICY_EVAL_CTX *ctx, X509 *issuer);
 108
 109 /* Gets the CT logs that are trusted sources of SCTs */
 110 const CTLOG_STORE *CT_POLICY_EVAL_CTX_get0_log_store(const CT_POLICY_EVAL_CTX *ctx);
 111
 112 /* Sets the log store that is in use. It must outlive the CT_POLICY_EVAL_CTX. */
 113 void CT_POLICY_EVAL_CTX_set_shared_CTLOG_STORE(CT_POLICY_EVAL_CTX *ctx,
 114                                                CTLOG_STORE *log_store);
 115
 116 /*
 117  * Gets the time, in milliseconds since the Unix epoch, that will be used as the
 118  * current time when checking whether an SCT was issued in the future.
 119  * Such SCTs will fail validation, as required by RFC6962.
 120  */
 121 uint64_t CT_POLICY_EVAL_CTX_get_time(const CT_POLICY_EVAL_CTX *ctx);
 122
 123 /*
 124  * Sets the time to evaluate SCTs against, in milliseconds since the Unix epoch.
 125  * If an SCT's timestamp is after this time, it will be interpreted as having
 126  * been issued in the future. RFC6962 states that "TLS clients MUST reject SCTs
 127  * whose timestamp is in the future", so an SCT will not validate in this case.
 128  */
 129 void CT_POLICY_EVAL_CTX_set_time(CT_POLICY_EVAL_CTX *ctx, uint64_t time_in_ms);
 130
 131 /*****************
 132  * SCT functions *
 133  *****************/
 134
 135 /*
 136  * Creates a new, blank SCT.
 137  * The caller is responsible for calling SCT_free when finished with the SCT.
 138  */
 139 SCT *SCT_new(void);
 140
 141 /*
 142  * Creates a new SCT from some base64-encoded strings.
 143  * The caller is responsible for calling SCT_free when finished with the SCT.
 144  */
 145 SCT *SCT_new_from_base64(unsigned char version,
 146                          const char *logid_base64,
 147                          ct_log_entry_type_t entry_type,
 148                          uint64_t timestamp,
 149                          const char *extensions_base64,
 150                          const char *signature_base64);
 151
 152 /*
 153  * Frees the SCT and the underlying data structures.
 154  */
 155 void SCT_free(SCT *sct);
 156
 157 /*
 158  * Free a stack of SCTs, and the underlying SCTs themselves.
 159  * Intended to be compatible with X509V3_EXT_FREE.
 160  */
 161 void SCT_LIST_free(STACK_OF(SCT) *a);
 162
 163 /*
 164  * Returns the version of the SCT.
 165  */
 166 sct_version_t SCT_get_version(const SCT *sct);
 167
 168 /*
 169  * Set the version of an SCT.
 170  * Returns 1 on success, 0 if the version is unrecognized.
 171  */
 172 __owur int SCT_set_version(SCT *sct, sct_version_t version);
 173
 174 /*
 175  * Returns the log entry type of the SCT.
 176  */
 177 ct_log_entry_type_t SCT_get_log_entry_type(const SCT *sct);
 178
 179 /*
 180  * Set the log entry type of an SCT.
 181  * Returns 1 on success, 0 otherwise.
 182  */
 183 __owur int SCT_set_log_entry_type(SCT *sct, ct_log_entry_type_t entry_type);
 184
 185 /*
 186  * Gets the ID of the log that an SCT came from.
 187  * Ownership of the log ID remains with the SCT.
 188  * Returns the length of the log ID.
 189  */
 190 size_t SCT_get0_log_id(const SCT *sct, unsigned char **log_id);
 191
 192 /*
 193  * Set the log ID of an SCT to point directly to the *log_id specified.
 194  * The SCT takes ownership of the specified pointer.
 195  * Returns 1 on success, 0 otherwise.
 196  */
 197 __owur int SCT_set0_log_id(SCT *sct, unsigned char *log_id, size_t log_id_len);
 198
 199 /*
 200  * Set the log ID of an SCT.
 201  * This makes a copy of the log_id.
 202  * Returns 1 on success, 0 otherwise.
 203  */
 204 __owur int SCT_set1_log_id(SCT *sct, const unsigned char *log_id,
 205                            size_t log_id_len);
 206
 207 /*
 208  * Returns the timestamp for the SCT (epoch time in milliseconds).
 209  */
 210 uint64_t SCT_get_timestamp(const SCT *sct);
 211
 212 /*
 213  * Set the timestamp of an SCT (epoch time in milliseconds).
 214  */
 215 void SCT_set_timestamp(SCT *sct, uint64_t timestamp);
 216
 217 /*
 218  * Return the NID for the signature used by the SCT.
 219  * For CT v1, this will be either NID_sha256WithRSAEncryption or
 220  * NID_ecdsa_with_SHA256 (or NID_undef if incorrect/unset).
 221  */
 222 int SCT_get_signature_nid(const SCT *sct);
 223
 224 /*
 225  * Set the signature type of an SCT
 226  * For CT v1, this should be either NID_sha256WithRSAEncryption or
 227  * NID_ecdsa_with_SHA256.
 228  * Returns 1 on success, 0 otherwise.
 229  */
 230 __owur int SCT_set_signature_nid(SCT *sct, int nid);
 231
 232 /*
 233  * Set *ext to point to the extension data for the SCT. ext must not be NULL.
 234  * The SCT retains ownership of this pointer.
 235  * Returns length of the data pointed to.
 236  */
 237 size_t SCT_get0_extensions(const SCT *sct, unsigned char **ext);
 238
 239 /*
 240  * Set the extensions of an SCT to point directly to the *ext specified.
 241  * The SCT takes ownership of the specified pointer.
 242  */
 243 void SCT_set0_extensions(SCT *sct, unsigned char *ext, size_t ext_len);
 244
 245 /*
 246  * Set the extensions of an SCT.
 247  * This takes a copy of the ext.
 248  * Returns 1 on success, 0 otherwise.
 249  */
 250 __owur int SCT_set1_extensions(SCT *sct, const unsigned char *ext,
 251                                size_t ext_len);
 252
 253 /*
 254  * Set *sig to point to the signature for the SCT. sig must not be NULL.
 255  * The SCT retains ownership of this pointer.
 256  * Returns length of the data pointed to.
 257  */
 258 size_t SCT_get0_signature(const SCT *sct, unsigned char **sig);
 259
 260 /*
 261  * Set the signature of an SCT to point directly to the *sig specified.
 262  * The SCT takes ownership of the specified pointer.
 263  */
 264 void SCT_set0_signature(SCT *sct, unsigned char *sig, size_t sig_len);
 265
 266 /*
 267  * Set the signature of an SCT to be a copy of the *sig specified.
 268  * Returns 1 on success, 0 otherwise.
 269  */
 270 __owur int SCT_set1_signature(SCT *sct, const unsigned char *sig,
 271                               size_t sig_len);
 272
 273 /*
 274  * The origin of this SCT, e.g. TLS extension, OCSP response, etc.
 275  */
 276 sct_source_t SCT_get_source(const SCT *sct);
 277
 278 /*
 279  * Set the origin of this SCT, e.g. TLS extension, OCSP response, etc.
 280  * Returns 1 on success, 0 otherwise.
 281  */
 282 __owur int SCT_set_source(SCT *sct, sct_source_t source);
 283
 284 /*
 285  * Returns a text string describing the validation status of |sct|.
 286  */
 287 const char *SCT_validation_status_string(const SCT *sct);
 288
 289 /*
 290  * Pretty-prints an |sct| to |out|.
 291  * It will be indented by the number of spaces specified by |indent|.
 292  * If |logs| is not NULL, it will be used to lookup the CT log that the SCT came
 293  * from, so that the log name can be printed.
 294  */
 295 void SCT_print(const SCT *sct, BIO *out, int indent, const CTLOG_STORE *logs);
 296
 297 /*
 298  * Pretty-prints an |sct_list| to |out|.
 299  * It will be indented by the number of spaces specified by |indent|.
 300  * SCTs will be delimited by |separator|.
 301  * If |logs| is not NULL, it will be used to lookup the CT log that each SCT
 302  * came from, so that the log names can be printed.
 303  */
 304 void SCT_LIST_print(const STACK_OF(SCT) *sct_list, BIO *out, int indent,
 305                     const char *separator, const CTLOG_STORE *logs);
 306
 307 /*
 308  * Gets the last result of validating this SCT.
 309  * If it has not been validated yet, returns SCT_VALIDATION_STATUS_NOT_SET.
 310  */
 311 sct_validation_status_t SCT_get_validation_status(const SCT *sct);
 312
 313 /*
 314  * Validates the given SCT with the provided context.
 315  * Sets the "validation_status" field of the SCT.
 316  * Returns 1 if the SCT is valid and the signature verifies.
 317  * Returns 0 if the SCT is invalid or could not be verified.
 318  * Returns -1 if an error occurs.
 319  */
 320 __owur int SCT_validate(SCT *sct, const CT_POLICY_EVAL_CTX *ctx);
 321
 322 /*
 323  * Validates the given list of SCTs with the provided context.
 324  * Sets the "validation_status" field of each SCT.
 325  * Returns 1 if there are no invalid SCTs and all signatures verify.
 326  * Returns 0 if at least one SCT is invalid or could not be verified.
 327  * Returns a negative integer if an error occurs.
 328  */
 329 __owur int SCT_LIST_validate(const STACK_OF(SCT) *scts,
 330                              CT_POLICY_EVAL_CTX *ctx);
 331
 332
 333 /*********************************
 334  * SCT parsing and serialisation *
 335  *********************************/
 336
 337 /*
 338  * Serialize (to TLS format) a stack of SCTs and return the length.
 339  * "a" must not be NULL.
 340  * If "pp" is NULL, just return the length of what would have been serialized.
 341  * If "pp" is not NULL and "*pp" is null, function will allocate a new pointer
 342  * for data that caller is responsible for freeing (only if function returns
 343  * successfully).
 344  * If "pp" is NULL and "*pp" is not NULL, caller is responsible for ensuring
 345  * that "*pp" is large enough to accept all of the serialized data.
 346  * Returns < 0 on error, >= 0 indicating bytes written (or would have been)
 347  * on success.
 348  */
 349 __owur int i2o_SCT_LIST(const STACK_OF(SCT) *a, unsigned char **pp);
 350
 351 /*
 352  * Convert TLS format SCT list to a stack of SCTs.
 353  * If "a" or "*a" is NULL, a new stack will be created that the caller is
 354  * responsible for freeing (by calling SCT_LIST_free).
 355  * "**pp" and "*pp" must not be NULL.
 356  * Upon success, "*pp" will point to after the last bytes read, and a stack
 357  * will be returned.
 358  * Upon failure, a NULL pointer will be returned, and the position of "*pp" is
 359  * not defined.
 360  */
 361 STACK_OF(SCT) *o2i_SCT_LIST(STACK_OF(SCT) **a, const unsigned char **pp,
 362                             size_t len);
 363
 364 /*
 365  * Serialize (to DER format) a stack of SCTs and return the length.
 366  * "a" must not be NULL.
 367  * If "pp" is NULL, just returns the length of what would have been serialized.
 368  * If "pp" is not NULL and "*pp" is null, function will allocate a new pointer
 369  * for data that caller is responsible for freeing (only if function returns
 370  * successfully).
 371  * If "pp" is NULL and "*pp" is not NULL, caller is responsible for ensuring
 372  * that "*pp" is large enough to accept all of the serialized data.
 373  * Returns < 0 on error, >= 0 indicating bytes written (or would have been)
 374  * on success.
 375  */
 376 __owur int i2d_SCT_LIST(const STACK_OF(SCT) *a, unsigned char **pp);
 377
 378 /*
 379  * Parses an SCT list in DER format and returns it.
 380  * If "a" or "*a" is NULL, a new stack will be created that the caller is
 381  * responsible for freeing (by calling SCT_LIST_free).
 382  * "**pp" and "*pp" must not be NULL.
 383  * Upon success, "*pp" will point to after the last bytes read, and a stack
 384  * will be returned.
 385  * Upon failure, a NULL pointer will be returned, and the position of "*pp" is
 386  * not defined.
 387  */
 388 STACK_OF(SCT) *d2i_SCT_LIST(STACK_OF(SCT) **a, const unsigned char **pp,
 389                             long len);
 390
 391 /*
 392  * Serialize (to TLS format) an |sct| and write it to |out|.
 393  * If |out| is null, no SCT will be output but the length will still be returned.
 394  * If |out| points to a null pointer, a string will be allocated to hold the
 395  * TLS-format SCT. It is the responsibility of the caller to free it.
 396  * If |out| points to an allocated string, the TLS-format SCT will be written
 397  * to it.
 398  * The length of the SCT in TLS format will be returned.
 399  */
 400 __owur int i2o_SCT(const SCT *sct, unsigned char **out);
 401
 402 /*
 403  * Parses an SCT in TLS format and returns it.
 404  * If |psct| is not null, it will end up pointing to the parsed SCT. If it
 405  * already points to a non-null pointer, the pointer will be free'd.
 406  * |in| should be a pointer to a string containing the TLS-format SCT.
 407  * |in| will be advanced to the end of the SCT if parsing succeeds.
 408  * |len| should be the length of the SCT in |in|.
 409  * Returns NULL if an error occurs.
 410  * If the SCT is an unsupported version, only the SCT's 'sct' and 'sct_len'
 411  * fields will be populated (with |in| and |len| respectively).
 412  */
 413 SCT *o2i_SCT(SCT **psct, const unsigned char **in, size_t len);
 414
 415 /********************
 416  * CT log functions *
 417  ********************/
 418
 419 /*
 420  * Creates a new CT log instance with the given |public_key| and |name| and
 421  * associates it with the give library context |libctx| and property query
 422  * string |propq|.
 423  * Takes ownership of |public_key| but copies |name|.
 424  * Returns NULL if malloc fails or if |public_key| cannot be converted to DER.
 425  * Should be deleted by the caller using CTLOG_free when no longer needed.
 426  */
 427 CTLOG *CTLOG_new_with_libctx(EVP_PKEY *public_key, const char *name,
 428                              OPENSSL_CTX *libctx, const char *propq);
 429
 430 /*
 431  * The same as CTLOG_new_with_libctx except that the default library context and
 432  * property query string are used.
 433  */
 434 CTLOG *CTLOG_new(EVP_PKEY *public_key, const char *name);
 435
 436 /*
 437  * Creates a new CTLOG instance with the base64-encoded SubjectPublicKeyInfo DER
 438  * in |pkey_base64| and associated with the given library context |libctx| and
 439  * property query string |propq|. The |name| is a string to help users identify
 440  * this log.
 441  * Returns 1 on success, 0 on failure.
 442  * Should be deleted by the caller using CTLOG_free when no longer needed.
 443  */
 444 int CTLOG_new_from_base64_with_libctx(CTLOG **ct_log, const char *pkey_base64,
 445                                       const char *name, OPENSSL_CTX *libctx,
 446                                       const char *propq);
 447
 448 /*
 449  * The same as CTLOG_new_from_base64_with_libctx() except that the default
 450  * library context and property query string are used.
 451  * Returns 1 on success, 0 on failure.
 452  */
 453 int CTLOG_new_from_base64(CTLOG ** ct_log,
 454                           const char *pkey_base64, const char *name);
 455
 456 /*
 457  * Deletes a CT log instance and its fields.
 458  */
 459 void CTLOG_free(CTLOG *log);
 460
 461 /* Gets the name of the CT log */
 462 const char *CTLOG_get0_name(const CTLOG *log);
 463 /* Gets the ID of the CT log */
 464 void CTLOG_get0_log_id(const CTLOG *log, const uint8_t **log_id,
 465                        size_t *log_id_len);
 466 /* Gets the public key of the CT log */
 467 EVP_PKEY *CTLOG_get0_public_key(const CTLOG *log);
 468
 469 /**************************
 470  * CT log store functions *
 471  **************************/
 472
 473 /*
 474  * Creates a new CT log store and associates it with the given libctx and
 475  * property query string.
 476  * Should be deleted by the caller using CTLOG_STORE_free when no longer needed.
 477  */
 478 CTLOG_STORE *CTLOG_STORE_new_with_libctx(OPENSSL_CTX *libctx, const char *propq);
 479
 480 /*
 481  * Same as CTLOG_STORE_new_with_libctx except that the default libctx and
 482  * property query string are used.
 483  * Should be deleted by the caller using CTLOG_STORE_free when no longer needed.
 484  */
 485 CTLOG_STORE *CTLOG_STORE_new(void);
 486
 487 /*
 488  * Deletes a CT log store and all of the CT log instances held within.
 489  */
 490 void CTLOG_STORE_free(CTLOG_STORE *store);
 491
 492 /*
 493  * Finds a CT log in the store based on its log ID.
 494  * Returns the CT log, or NULL if no match is found.
 495  */
 496 const CTLOG *CTLOG_STORE_get0_log_by_id(const CTLOG_STORE *store,
 497                                         const uint8_t *log_id,
 498                                         size_t log_id_len);
 499
 500 /*
 501  * Loads a CT log list into a |store| from a |file|.
 502  * Returns 1 if loading is successful, or 0 otherwise.
 503  */
 504 __owur int CTLOG_STORE_load_file(CTLOG_STORE *store, const char *file);
 505
 506 /*
 507  * Loads the default CT log list into a |store|.
 508  * Returns 1 if loading is successful, or 0 otherwise.
 509  */
 510 __owur int CTLOG_STORE_load_default_file(CTLOG_STORE *store);
 511
 512 #  ifdef  __cplusplus
 513 }
 514 #  endif
 515 # endif
 516 #endif