tf2 handshake.cpp

const uint32_t CONNECTIONLESS_HEADER = 0xFFFFFFFF;

const uint8_t A2S_GETCHALLENGE = 'q';
const uint8_t S2C_CHALLENGE = 'A';
const uint8_t C2S_CONNECT = 'k';
const uint8_t S2C_CONNECTION = 'B';

const uint32_t PROTOCOL_HASHEDCDKEY = 0x02;
const uint32_t PROTOCOL_STEAM = 0x03;

const uint32_t NETPROTOCOL_VERSION = 24;



struct a2s_getchallenge
{
    uint32_t header = CONNECTIONLESS_HEADER;
    char msg_type = A2S_GETCHALLENGE;
    uint32_t client_challenge; // Random value
    char pad[11] = "0000000000"; // null terminated
};

struct s2c_challenge
{
    uint32_t header = CONNECTIONLESS_HEADER;
    char msg_type = S2C_CHALLENGE;
    uint32_t source_protocol;
    uint32_t server_challenge;
    uint32_t client_challenge;
    uint32_t auth_protocol = PROTOCOL_HASHEDCDKEY;
    char pad[7] = "000000";
};

struct c2s_connect
{
    uint32_t header = CONNECTIONLESS_HEADER;
    char msg_type = C2S_CONNECT;
    uint32_t protocol_version = NETPROTOCOL_VERSION;
    uint32_t auth_type = PROTOCOL_HASHEDCDKEY;
    uint32_t server_challenge;
    uint32_t client_challenge;
    char* name;
    char pad = '\0';
    char* password;
    char* cdkey_hash; // md5_hash
};

struct s2c_connection
{
    uint32_t header = CONNECTIONLESS_HEADER;
    char msg_type = S2C_CONNECTION;
    char pad[11] = "0000000000";
};