text: /*
   *
   * Copyright 2018 gRPC authors.
   *
   * Licensed under the Apache License, Version 2.0 (the "License");
   * you may not use this file except in compliance with the License.
   * You may obtain a copy of the License at
   *
   *     http://www.apache.org/licenses/LICENSE-2.0
   *
   * Unless required by applicable law or agreed to in writing, software
   * distributed under the License is distributed on an "AS IS" BASIS,
   * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
   * See the License for the specific language governing permissions and
   * limitations under the License.
   *
   */
  
  #ifndef GRPC_CORE_TSI_ALTS_ZERO_COPY_FRAME_PROTECTOR_ALTS_IOVEC_RECORD_PROTOCOL_H
  #define GRPC_CORE_TSI_ALTS_ZERO_COPY_FRAME_PROTECTOR_ALTS_IOVEC_RECORD_PROTOCOL_H
  
  #include <grpc/support/port_platform.h>
  
  #include <stdbool.h>
  
  #include "src/core/tsi/alts/crypt/gsec.h"
  
  constexpr size_t kZeroCopyFrameMessageType = 0x06;
  constexpr size_t kZeroCopyFrameLengthFieldSize = 4;
  constexpr size_t kZeroCopyFrameMessageTypeFieldSize = 4;
  constexpr size_t kZeroCopyFrameHeaderSize =
      kZeroCopyFrameLengthFieldSize + kZeroCopyFrameMessageTypeFieldSize;
  
  // Limit k on number of frames such that at most 2^(8 * k) frames can be sent.
  constexpr size_t kAltsRecordProtocolRekeyFrameLimit = 8;
  constexpr size_t kAltsRecordProtocolFrameLimit = 5;
  
  /* An implementation of alts record protocol. The API is thread-compatible. */
  
  typedef struct iovec iovec_t;
  
  typedef struct alts_iovec_record_protocol alts_iovec_record_protocol;
  
  /**
   * This method gets the length of record protocol frame header.
   */
  size_t alts_iovec_record_protocol_get_header_length();
  
  /**
   * This method gets the length of record protocol frame tag.
   *
   * - rp: an alts_iovec_record_protocol instance.
   *
   * On success, the method returns the length of record protocol frame tag.
   * Otherwise, it returns zero.
   */
  size_t alts_iovec_record_protocol_get_tag_length(
      const alts_iovec_record_protocol* rp);
  
  /**
   * This method returns maximum allowed unprotected data size, given maximum
   * protected frame size.
   *
   * - rp: an alts_iovec_record_protocol instance.
   * - max_protected_frame_size: maximum protected frame size.
   *
   * On success, the method returns the maximum allowed unprotected data size.
   * Otherwise, it returns zero.
   */
  size_t alts_iovec_record_protocol_max_unprotected_data_size(
      const alts_iovec_record_protocol* rp, size_t max_protected_frame_size);
  
  /**
   * This method performs integrity-only protect operation on a
   * alts_iovec_record_protocol instance, i.e., compute frame header and tag. The
   * caller needs to allocate the memory for header and tag prior to calling this
   * method.
   *
   * - rp: an alts_iovec_record_protocol instance.
   * - unprotected_vec: an iovec array containing unprotected data.
   * - unprotected_vec_length: the array length of unprotected_vec.
   * - header: an iovec containing the output frame header.
   * - tag: an iovec containing the output frame tag.
   * - error_details: a buffer containing an error message if the method does not
   *   function correctly. It is OK to pass nullptr into error_details.
   *
   * On success, the method returns GRPC_STATUS_OK. Otherwise, it returns an
   * error status code along with its details specified in error_details (if
   * error_details is not nullptr).
   */
  grpc_status_code alts_iovec_record_protocol_integrity_only_protect(
      alts_iovec_record_protocol* rp, const iovec_t* unprotected_vec,
      size_t unprotected_vec_length, iovec_t header, iovec_t tag,
      char** error_details);
  
  /**
   * This method performs integrity-only unprotect operation on a
   * alts_iovec_record_protocol instance, i.e., verify frame header and tag.
   *
   * - rp: an alts_iovec_record_protocol instance.
   * - protected_vec: an iovec array containing protected data.
   * - protected_vec_length: the array length of protected_vec.
   * - header: an iovec containing the frame header.
   * - tag: an iovec containing the frame tag.
   * - error_details: a buffer containing an error message if the method does not
   *   function correctly. It is OK to pass nullptr into error_details.
   *
   * On success, the method returns GRPC_STATUS_OK. Otherwise, it returns an
   * error status code along with its details specified in error_details (if
   * error_details is not nullptr).
   */
  grpc_status_code alts_iovec_record_protocol_integrity_only_unprotect(
      alts_iovec_record_protocol* rp, const iovec_t* protected_vec,
      size_t protected_vec_length, iovec_t header, iovec_t tag,
      char** error_details);
  
  /**
   * This method performs privacy-integrity protect operation on a
   * alts_iovec_record_protocol instance, i.e., compute a protected frame. The
   * caller needs to allocate the memory for the protected frame prior to calling
   * this method.
   *
   * - rp: an alts_iovec_record_protocol instance.
   * - unprotected_vec: an iovec array containing unprotected data.
   * - unprotected_vec_length: the array length of unprotected_vec.
   * - protected_frame: an iovec containing the output protected frame.
   * - error_details: a buffer containing an error message if the method does not
   *   function correctly. It is OK to pass nullptr into error_details.
   *
   * On success, the method returns GRPC_STATUS_OK. Otherwise, it returns an
   * error status code along with its details specified in error_details (if
   * error_details is not nullptr).
   */
  grpc_status_code alts_iovec_record_protocol_privacy_integrity_protect(
      alts_iovec_record_protocol* rp, const iovec_t* unprotected_vec,
      size_t unprotected_vec_length, iovec_t protected_frame,
      char** error_details);
  
  /**
   * This method performs privacy-integrity unprotect operation on a
   * alts_iovec_record_protocol instance given a full protected frame, i.e.,
   * compute the unprotected data. The caller needs to allocated the memory for
   * the unprotected data prior to calling this method.
   *
   * - rp: an alts_iovec_record_protocol instance.
   * - header: an iovec containing the frame header.
   * - protected_vec: an iovec array containing protected data including the tag.
   * - protected_vec_length: the array length of protected_vec.
   * - unprotected_data: an iovec containing the output unprotected data.
   * - error_details: a buffer containing an error message if the method does not
   *   function correctly. It is OK to pass nullptr into error_details.
   *
   * On success, the method returns GRPC_STATUS_OK. Otherwise, it returns an
   * error status code along with its details specified in error_details (if
   * error_details is not nullptr).
   */
  grpc_status_code alts_iovec_record_protocol_privacy_integrity_unprotect(
      alts_iovec_record_protocol* rp, iovec_t header,
      const iovec_t* protected_vec, size_t protected_vec_length,
      iovec_t unprotected_data, char** error_details);
  
  /**
   * This method creates an alts_iovec_record_protocol instance, given a
   * gsec_aead_crypter instance, a flag indicating if the created instance will be
   * used at the client or server side, and a flag indicating if the created
   * instance will be used for integrity-only mode or privacy-integrity mode. The
   * ownership of gsec_aead_crypter instance is transferred to this new object.
   *
   * - crypter: a gsec_aead_crypter instance used to perform AEAD decryption.
   * - overflow_size: overflow size of counter in bytes.
   * - is_client: a flag indicating if the alts_iovec_record_protocol instance
   *   will be used at the client or server side.
   * - is_integrity_only: a flag indicating if the alts_iovec_record_protocol
   *   instance will be used for integrity-only or privacy-integrity mode.
   * - is_protect: a flag indicating if the alts_grpc_record_protocol instance
   *   will be used for protect or unprotect.
   * - rp: an alts_iovec_record_protocol instance to be returned from
   *   the method.
   * - error_details: a buffer containing an error message if the method does not
   *   function correctly. It is OK to pass nullptr into error_details.
   *
   * On success, the method returns GRPC_STATUS_OK. Otherwise, it returns an
   * error status code along with its details specified in error_details (if
   * error_details is not nullptr).
   */
  grpc_status_code alts_iovec_record_protocol_create(
      gsec_aead_crypter* crypter, size_t overflow_size, bool is_client,
      bool is_integrity_only, bool is_protect, alts_iovec_record_protocol** rp,
      char** error_details);
  
  /**
   * This method destroys an alts_iovec_record_protocol instance by de-allocating
   * all of its occupied memory. A gsec_aead_crypter instance passed in at
   * gsec_alts_crypter instance creation time will be destroyed in this method.
   */
  void alts_iovec_record_protocol_destroy(alts_iovec_record_protocol* rp);
  
  #endif /* GRPC_CORE_TSI_ALTS_ZERO_COPY_FRAME_PROTECTOR_ALTS_IOVEC_RECORD_PROTOCOL_H \
          */
  