bool GetClientAuthString(int client, char[] auth, int maxlen, bool validate)
bool GetClientAuthId(int client, AuthIdType authType, char[] auth, int maxlen, bool validate)
enum AuthIdType
{
AuthId_Engine = 0, /**< The game-specific auth string as returned from the engine */
// The following are only available on games that support Steam authentication.
AuthId_Steam2, /**< Steam2 rendered format, ex "STEAM_1:1:4153990" */
AuthId_Steam3, /**< Steam3 rendered format, ex "[U:1:8307981]" */
AuthId_SteamID64, /**< A SteamID64 (uint64) as a String, ex "76561197968573709" */
};