syntax = "proto3";

import "constants.proto";

/* A message must be of type Cmd0 / Cmd1 / Resp0 / Resp1 */
enum Sec2MsgType {
    S2Session_Command0 = 0;
    S2Session_Response0 = 1;
    S2Session_Command1 = 2;
    S2Session_Response1 = 3;
}

// NOTE: Client: Host (shell, Android/iOS) | Device: ESP32-XX
/* Data structure of Session command0 packet */
message S2SessionCmd0 {
    bytes client_username = 1;
    bytes client_pubkey = 2;
}

/* Data structure of Session response0 packet */
message S2SessionResp0 {
    Status status = 1;
    bytes device_pubkey = 2;
    bytes device_salt = 3;
}

/* Data structure of Session command1 packet */
message S2SessionCmd1 {
    bytes client_proof = 1;
}

/* Data structure of Session response1 packet */
message S2SessionResp1 {
    Status status = 1;
    bytes device_proof = 2;
    bytes device_nonce = 3;
}

/* Payload structure of session data */
message Sec2Payload {
    Sec2MsgType msg = 1;        /*!< Type of message */
    oneof payload {
        S2SessionCmd0 sc0 = 20;   /*!< Payload data interpreted as Cmd0 */
        S2SessionResp0 sr0 = 21;  /*!< Payload data interpreted as Resp0 */
        S2SessionCmd1 sc1 = 22;   /*!< Payload data interpreted as Cmd1 */
        S2SessionResp1 sr1 = 23;  /*!< Payload data interpreted as Resp1 */
    }
}