int auth_check_password(const char *username, const char *password);
char * auth_login(const char *username, const char *password);
int auth_logout(const char *username, const char *token);
int auth_check_token(const char *username, const char *given_token);
int auth_check_password(const char *username, const char *password);
char * auth_login(const char *username, const char *password);
int auth_logout(const char *username, const char *token);
int auth_check_token(const char *username, const char *given_token);