text: /*
   * Copyright (c) 2020 Doc.ai and/or its affiliates.
   * 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 __included_wg_messages_h__
  #define __included_wg_messages_h__
  
  #include <stdint.h>
  #include <wireguard/wireguard_noise.h>
  #include <wireguard/wireguard_cookie.h>
  
  #define WG_TICK 0.01				/**< WG tick period (s) */
  #define WHZ (u32) (1/WG_TICK)		/**< WG tick frequency */
  
  #define NOISE_KEY_LEN_BASE64 ((((NOISE_PUBLIC_KEY_LEN) + 2) / 3) * 4 + 1)
  #define noise_encrypted_len(plain_len) ((plain_len) + NOISE_AUTHTAG_LEN)
  
  enum limits
  {
    REKEY_TIMEOUT = 5,
    REKEY_TIMEOUT_JITTER = WHZ / 3,
    KEEPALIVE_TIMEOUT = 10,
    MAX_TIMER_HANDSHAKES = 90 / REKEY_TIMEOUT,
    MAX_PEERS = 1U << 20
  };
  
  #define foreach_wg_message_type	\
    _(INVALID, "Invalid")		\
    _(HANDSHAKE_INITIATION, "Handshake initiation")		\
    _(HANDSHAKE_RESPONSE, "Handshake response") \
    _(HANDSHAKE_COOKIE, "Handshake cookie") \
    _(DATA, "Data") \
  
  typedef enum message_type
  {
  #define _(v,s) MESSAGE_##v,
    foreach_wg_message_type
  #undef _
  } message_type_t;
  
  typedef struct message_header
  {
    message_type_t type;
  } message_header_t;
  
  typedef struct message_handshake_initiation
  {
    message_header_t header;
    u32 sender_index;
    u8 unencrypted_ephemeral[NOISE_PUBLIC_KEY_LEN];
    u8 encrypted_static[noise_encrypted_len (NOISE_PUBLIC_KEY_LEN)];
    u8 encrypted_timestamp[noise_encrypted_len (NOISE_TIMESTAMP_LEN)];
    message_macs_t macs;
  } message_handshake_initiation_t;
  
  typedef struct message_handshake_response
  {
    message_header_t header;
    u32 sender_index;
    u32 receiver_index;
    u8 unencrypted_ephemeral[NOISE_PUBLIC_KEY_LEN];
    u8 encrypted_nothing[noise_encrypted_len (0)];
    message_macs_t macs;
  } message_handshake_response_t;
  
  typedef struct message_handshake_cookie
  {
    message_header_t header;
    u32 receiver_index;
    u8 nonce[COOKIE_NONCE_SIZE];
    u8 encrypted_cookie[noise_encrypted_len (COOKIE_MAC_SIZE)];
  } message_handshake_cookie_t;
  
  typedef struct message_data
  {
    message_header_t header;
    u32 receiver_index;
    u64 counter;
    u8 encrypted_data[];
  } message_data_t;
  
  #define message_data_len(plain_len) \
      (noise_encrypted_len(plain_len) + sizeof(message_data_t))
  
  #endif /* __included_wg_messages_h__ */
  
  /*
   * fd.io coding-style-patch-verification: ON
   *
   * Local Variables:
   * eval: (c-set-style "gnu")
   * End:
   */
  