text: /*
   * Copyright 2016-2018 The OpenSSL Project Authors. All Rights Reserved.
   *
   * Licensed under the Apache License 2.0 (the "License").  You may not use
   * this file except in compliance with the License.  You can obtain a copy
   * in the file LICENSE in the source distribution or at
   * https://www.openssl.org/source/license.html
   */
  
  #ifndef OPENSSL_CT_H
  # define OPENSSL_CT_H
  # pragma once
  
  # include <openssl/macros.h>
  # ifndef OPENSSL_NO_DEPRECATED_3_0
  #  define HEADER_CT_H
  # endif
  
  # include <openssl/opensslconf.h>
  
  # ifndef OPENSSL_NO_CT
  # include <openssl/types.h>
  # include <openssl/safestack.h>
  # include <openssl/x509.h>
  # include <openssl/cterr.h>
  # ifdef  __cplusplus
  extern "C" {
  # endif
  
  
  /* Minimum RSA key size, from RFC6962 */
  # define SCT_MIN_RSA_BITS 2048
  
  /* All hashes are SHA256 in v1 of Certificate Transparency */
  # define CT_V1_HASHLEN SHA256_DIGEST_LENGTH
  
  typedef enum {
      CT_LOG_ENTRY_TYPE_NOT_SET = -1,
      CT_LOG_ENTRY_TYPE_X509 = 0,
      CT_LOG_ENTRY_TYPE_PRECERT = 1
  } ct_log_entry_type_t;
  
  typedef enum {
      SCT_VERSION_NOT_SET = -1,
      SCT_VERSION_V1 = 0
  } sct_version_t;
  
  typedef enum {
      SCT_SOURCE_UNKNOWN,
      SCT_SOURCE_TLS_EXTENSION,
      SCT_SOURCE_X509V3_EXTENSION,
      SCT_SOURCE_OCSP_STAPLED_RESPONSE
  } sct_source_t;
  
  typedef enum {
      SCT_VALIDATION_STATUS_NOT_SET,
      SCT_VALIDATION_STATUS_UNKNOWN_LOG,
      SCT_VALIDATION_STATUS_VALID,
      SCT_VALIDATION_STATUS_INVALID,
      SCT_VALIDATION_STATUS_UNVERIFIED,
      SCT_VALIDATION_STATUS_UNKNOWN_VERSION
  } sct_validation_status_t;
  
  DEFINE_STACK_OF(SCT)
  DEFINE_STACK_OF(CTLOG)
  
  /******************************************
   * CT policy evaluation context functions *
   ******************************************/
  
  /*
   * Creates a new, empty policy evaluation context.
   * The caller is responsible for calling CT_POLICY_EVAL_CTX_free when finished
   * with the CT_POLICY_EVAL_CTX.
   */
  CT_POLICY_EVAL_CTX *CT_POLICY_EVAL_CTX_new(void);
  
  /* Deletes a policy evaluation context and anything it owns. */
  void CT_POLICY_EVAL_CTX_free(CT_POLICY_EVAL_CTX *ctx);
  
  /* Gets the peer certificate that the SCTs are for */
  X509* CT_POLICY_EVAL_CTX_get0_cert(const CT_POLICY_EVAL_CTX *ctx);
  
  /*
   * Sets the certificate associated with the received SCTs.
   * Increments the reference count of cert.
   * Returns 1 on success, 0 otherwise.
   */
  int CT_POLICY_EVAL_CTX_set1_cert(CT_POLICY_EVAL_CTX *ctx, X509 *cert);
  
  /* Gets the issuer of the aforementioned certificate */
  X509* CT_POLICY_EVAL_CTX_get0_issuer(const CT_POLICY_EVAL_CTX *ctx);
  
  /*
   * Sets the issuer of the certificate associated with the received SCTs.
   * Increments the reference count of issuer.
   * Returns 1 on success, 0 otherwise.
   */
  int CT_POLICY_EVAL_CTX_set1_issuer(CT_POLICY_EVAL_CTX *ctx, X509 *issuer);
  
  /* Gets the CT logs that are trusted sources of SCTs */
  const CTLOG_STORE *CT_POLICY_EVAL_CTX_get0_log_store(const CT_POLICY_EVAL_CTX *ctx);
  
  /* Sets the log store that is in use. It must outlive the CT_POLICY_EVAL_CTX. */
  void CT_POLICY_EVAL_CTX_set_shared_CTLOG_STORE(CT_POLICY_EVAL_CTX *ctx,
                                                 CTLOG_STORE *log_store);
  
  /*
   * Gets the time, in milliseconds since the Unix epoch, that will be used as the
   * current time when checking whether an SCT was issued in the future.
   * Such SCTs will fail validation, as required by RFC6962.
   */
  uint64_t CT_POLICY_EVAL_CTX_get_time(const CT_POLICY_EVAL_CTX *ctx);
  
  /*
   * Sets the time to evaluate SCTs against, in milliseconds since the Unix epoch.
   * If an SCT's timestamp is after this time, it will be interpreted as having
   * been issued in the future. RFC6962 states that "TLS clients MUST reject SCTs
   * whose timestamp is in the future", so an SCT will not validate in this case.
   */
  void CT_POLICY_EVAL_CTX_set_time(CT_POLICY_EVAL_CTX *ctx, uint64_t time_in_ms);
  
  /*****************
   * SCT functions *
   *****************/
  
  /*
   * Creates a new, blank SCT.
   * The caller is responsible for calling SCT_free when finished with the SCT.
   */
  SCT *SCT_new(void);
  
  /*
   * Creates a new SCT from some base64-encoded strings.
   * The caller is responsible for calling SCT_free when finished with the SCT.
   */
  SCT *SCT_new_from_base64(unsigned char version,
                           const char *logid_base64,
                           ct_log_entry_type_t entry_type,
                           uint64_t timestamp,
                           const char *extensions_base64,
                           const char *signature_base64);
  
  /*
   * Frees the SCT and the underlying data structures.
   */
  void SCT_free(SCT *sct);
  
  /*
   * Free a stack of SCTs, and the underlying SCTs themselves.
   * Intended to be compatible with X509V3_EXT_FREE.
   */
  void SCT_LIST_free(STACK_OF(SCT) *a);
  
  /*
   * Returns the version of the SCT.
   */
  sct_version_t SCT_get_version(const SCT *sct);
  
  /*
   * Set the version of an SCT.
   * Returns 1 on success, 0 if the version is unrecognized.
   */
  __owur int SCT_set_version(SCT *sct, sct_version_t version);
  
  /*
   * Returns the log entry type of the SCT.
   */
  ct_log_entry_type_t SCT_get_log_entry_type(const SCT *sct);
  
  /*
   * Set the log entry type of an SCT.
   * Returns 1 on success, 0 otherwise.
   */
  __owur int SCT_set_log_entry_type(SCT *sct, ct_log_entry_type_t entry_type);
  
  /*
   * Gets the ID of the log that an SCT came from.
   * Ownership of the log ID remains with the SCT.
   * Returns the length of the log ID.
   */
  size_t SCT_get0_log_id(const SCT *sct, unsigned char **log_id);
  
  /*
   * Set the log ID of an SCT to point directly to the *log_id specified.
   * The SCT takes ownership of the specified pointer.
   * Returns 1 on success, 0 otherwise.
   */
  __owur int SCT_set0_log_id(SCT *sct, unsigned char *log_id, size_t log_id_len);
  
  /*
   * Set the log ID of an SCT.
   * This makes a copy of the log_id.
   * Returns 1 on success, 0 otherwise.
   */
  __owur int SCT_set1_log_id(SCT *sct, const unsigned char *log_id,
                             size_t log_id_len);
  
  /*
   * Returns the timestamp for the SCT (epoch time in milliseconds).
   */
  uint64_t SCT_get_timestamp(const SCT *sct);
  
  /*
   * Set the timestamp of an SCT (epoch time in milliseconds).
   */
  void SCT_set_timestamp(SCT *sct, uint64_t timestamp);
  
  /*
   * Return the NID for the signature used by the SCT.
   * For CT v1, this will be either NID_sha256WithRSAEncryption or
   * NID_ecdsa_with_SHA256 (or NID_undef if incorrect/unset).
   */
  int SCT_get_signature_nid(const SCT *sct);
  
  /*
   * Set the signature type of an SCT
   * For CT v1, this should be either NID_sha256WithRSAEncryption or
   * NID_ecdsa_with_SHA256.
   * Returns 1 on success, 0 otherwise.
   */
  __owur int SCT_set_signature_nid(SCT *sct, int nid);
  
  /*
   * Set *ext to point to the extension data for the SCT. ext must not be NULL.
   * The SCT retains ownership of this pointer.
   * Returns length of the data pointed to.
   */
  size_t SCT_get0_extensions(const SCT *sct, unsigned char **ext);
  
  /*
   * Set the extensions of an SCT to point directly to the *ext specified.
   * The SCT takes ownership of the specified pointer.
   */
  void SCT_set0_extensions(SCT *sct, unsigned char *ext, size_t ext_len);
  
  /*
   * Set the extensions of an SCT.
   * This takes a copy of the ext.
   * Returns 1 on success, 0 otherwise.
   */
  __owur int SCT_set1_extensions(SCT *sct, const unsigned char *ext,
                                 size_t ext_len);
  
  /*
   * Set *sig to point to the signature for the SCT. sig must not be NULL.
   * The SCT retains ownership of this pointer.
   * Returns length of the data pointed to.
   */
  size_t SCT_get0_signature(const SCT *sct, unsigned char **sig);
  
  /*
   * Set the signature of an SCT to point directly to the *sig specified.
   * The SCT takes ownership of the specified pointer.
   */
  void SCT_set0_signature(SCT *sct, unsigned char *sig, size_t sig_len);
  
  /*
   * Set the signature of an SCT to be a copy of the *sig specified.
   * Returns 1 on success, 0 otherwise.
   */
  __owur int SCT_set1_signature(SCT *sct, const unsigned char *sig,
                                size_t sig_len);
  
  /*
   * The origin of this SCT, e.g. TLS extension, OCSP response, etc.
   */
  sct_source_t SCT_get_source(const SCT *sct);
  
  /*
   * Set the origin of this SCT, e.g. TLS extension, OCSP response, etc.
   * Returns 1 on success, 0 otherwise.
   */
  __owur int SCT_set_source(SCT *sct, sct_source_t source);
  
  /*
   * Returns a text string describing the validation status of |sct|.
   */
  const char *SCT_validation_status_string(const SCT *sct);
  
  /*
   * Pretty-prints an |sct| to |out|.
   * It will be indented by the number of spaces specified by |indent|.
   * If |logs| is not NULL, it will be used to lookup the CT log that the SCT came
   * from, so that the log name can be printed.
   */
  void SCT_print(const SCT *sct, BIO *out, int indent, const CTLOG_STORE *logs);
  
  /*
   * Pretty-prints an |sct_list| to |out|.
   * It will be indented by the number of spaces specified by |indent|.
   * SCTs will be delimited by |separator|.
   * If |logs| is not NULL, it will be used to lookup the CT log that each SCT
   * came from, so that the log names can be printed.
   */
  void SCT_LIST_print(const STACK_OF(SCT) *sct_list, BIO *out, int indent,
                      const char *separator, const CTLOG_STORE *logs);
  
  /*
   * Gets the last result of validating this SCT.
   * If it has not been validated yet, returns SCT_VALIDATION_STATUS_NOT_SET.
   */
  sct_validation_status_t SCT_get_validation_status(const SCT *sct);
  
  /*
   * Validates the given SCT with the provided context.
   * Sets the "validation_status" field of the SCT.
   * Returns 1 if the SCT is valid and the signature verifies.
   * Returns 0 if the SCT is invalid or could not be verified.
   * Returns -1 if an error occurs.
   */
  __owur int SCT_validate(SCT *sct, const CT_POLICY_EVAL_CTX *ctx);
  
  /*
   * Validates the given list of SCTs with the provided context.
   * Sets the "validation_status" field of each SCT.
   * Returns 1 if there are no invalid SCTs and all signatures verify.
   * Returns 0 if at least one SCT is invalid or could not be verified.
   * Returns a negative integer if an error occurs.
   */
  __owur int SCT_LIST_validate(const STACK_OF(SCT) *scts,
                               CT_POLICY_EVAL_CTX *ctx);
  
  
  /*********************************
   * SCT parsing and serialisation *
   *********************************/
  
  /*
   * Serialize (to TLS format) a stack of SCTs and return the length.
   * "a" must not be NULL.
   * If "pp" is NULL, just return the length of what would have been serialized.
   * If "pp" is not NULL and "*pp" is null, function will allocate a new pointer
   * for data that caller is responsible for freeing (only if function returns
   * successfully).
   * If "pp" is NULL and "*pp" is not NULL, caller is responsible for ensuring
   * that "*pp" is large enough to accept all of the serialized data.
   * Returns < 0 on error, >= 0 indicating bytes written (or would have been)
   * on success.
   */
  __owur int i2o_SCT_LIST(const STACK_OF(SCT) *a, unsigned char **pp);
  
  /*
   * Convert TLS format SCT list to a stack of SCTs.
   * If "a" or "*a" is NULL, a new stack will be created that the caller is
   * responsible for freeing (by calling SCT_LIST_free).
   * "**pp" and "*pp" must not be NULL.
   * Upon success, "*pp" will point to after the last bytes read, and a stack
   * will be returned.
   * Upon failure, a NULL pointer will be returned, and the position of "*pp" is
   * not defined.
   */
  STACK_OF(SCT) *o2i_SCT_LIST(STACK_OF(SCT) **a, const unsigned char **pp,
                              size_t len);
  
  /*
   * Serialize (to DER format) a stack of SCTs and return the length.
   * "a" must not be NULL.
   * If "pp" is NULL, just returns the length of what would have been serialized.
   * If "pp" is not NULL and "*pp" is null, function will allocate a new pointer
   * for data that caller is responsible for freeing (only if function returns
   * successfully).
   * If "pp" is NULL and "*pp" is not NULL, caller is responsible for ensuring
   * that "*pp" is large enough to accept all of the serialized data.
   * Returns < 0 on error, >= 0 indicating bytes written (or would have been)
   * on success.
   */
  __owur int i2d_SCT_LIST(const STACK_OF(SCT) *a, unsigned char **pp);
  
  /*
   * Parses an SCT list in DER format and returns it.
   * If "a" or "*a" is NULL, a new stack will be created that the caller is
   * responsible for freeing (by calling SCT_LIST_free).
   * "**pp" and "*pp" must not be NULL.
   * Upon success, "*pp" will point to after the last bytes read, and a stack
   * will be returned.
   * Upon failure, a NULL pointer will be returned, and the position of "*pp" is
   * not defined.
   */
  STACK_OF(SCT) *d2i_SCT_LIST(STACK_OF(SCT) **a, const unsigned char **pp,
                              long len);
  
  /*
   * Serialize (to TLS format) an |sct| and write it to |out|.
   * If |out| is null, no SCT will be output but the length will still be returned.
   * If |out| points to a null pointer, a string will be allocated to hold the
   * TLS-format SCT. It is the responsibility of the caller to free it.
   * If |out| points to an allocated string, the TLS-format SCT will be written
   * to it.
   * The length of the SCT in TLS format will be returned.
   */
  __owur int i2o_SCT(const SCT *sct, unsigned char **out);
  
  /*
   * Parses an SCT in TLS format and returns it.
   * If |psct| is not null, it will end up pointing to the parsed SCT. If it
   * already points to a non-null pointer, the pointer will be free'd.
   * |in| should be a pointer to a string containing the TLS-format SCT.
   * |in| will be advanced to the end of the SCT if parsing succeeds.
   * |len| should be the length of the SCT in |in|.
   * Returns NULL if an error occurs.
   * If the SCT is an unsupported version, only the SCT's 'sct' and 'sct_len'
   * fields will be populated (with |in| and |len| respectively).
   */
  SCT *o2i_SCT(SCT **psct, const unsigned char **in, size_t len);
  
  /********************
   * CT log functions *
   ********************/
  
  /*
   * Creates a new CT log instance with the given |public_key| and |name|.
   * Takes ownership of |public_key| but copies |name|.
   * Returns NULL if malloc fails or if |public_key| cannot be converted to DER.
   * Should be deleted by the caller using CTLOG_free when no longer needed.
   */
  CTLOG *CTLOG_new(EVP_PKEY *public_key, const char *name);
  
  /*
   * Creates a new CTLOG instance with the base64-encoded SubjectPublicKeyInfo DER
   * in |pkey_base64|. The |name| is a string to help users identify this log.
   * Returns 1 on success, 0 on failure.
   * Should be deleted by the caller using CTLOG_free when no longer needed.
   */
  int CTLOG_new_from_base64(CTLOG ** ct_log,
                            const char *pkey_base64, const char *name);
  
  /*
   * Deletes a CT log instance and its fields.
   */
  void CTLOG_free(CTLOG *log);
  
  /* Gets the name of the CT log */
  const char *CTLOG_get0_name(const CTLOG *log);
  /* Gets the ID of the CT log */
  void CTLOG_get0_log_id(const CTLOG *log, const uint8_t **log_id,
                         size_t *log_id_len);
  /* Gets the public key of the CT log */
  EVP_PKEY *CTLOG_get0_public_key(const CTLOG *log);
  
  /**************************
   * CT log store functions *
   **************************/
  
  /*
   * Creates a new CT log store.
   * Should be deleted by the caller using CTLOG_STORE_free when no longer needed.
   */
  CTLOG_STORE *CTLOG_STORE_new(void);
  
  /*
   * Deletes a CT log store and all of the CT log instances held within.
   */
  void CTLOG_STORE_free(CTLOG_STORE *store);
  
  /*
   * Finds a CT log in the store based on its log ID.
   * Returns the CT log, or NULL if no match is found.
   */
  const CTLOG *CTLOG_STORE_get0_log_by_id(const CTLOG_STORE *store,
                                          const uint8_t *log_id,
                                          size_t log_id_len);
  
  /*
   * Loads a CT log list into a |store| from a |file|.
   * Returns 1 if loading is successful, or 0 otherwise.
   */
  __owur int CTLOG_STORE_load_file(CTLOG_STORE *store, const char *file);
  
  /*
   * Loads the default CT log list into a |store|.
   * Returns 1 if loading is successful, or 0 otherwise.
   */
  __owur int CTLOG_STORE_load_default_file(CTLOG_STORE *store);
  
  #  ifdef  __cplusplus
  }
  #  endif
  # endif
  #endif
  