/**
* Authenticates the controller to the Tor server.
*
* <p>By default, the current Tor implementation trusts all local users, and the controller can
* authenticate itself by calling authenticate(new byte[0]).
*
* <p>If the 'CookieAuthentication' option is true, Tor writes a "magic cookie" file named
* "control_auth_cookie" into its data directory. To authenticate, the controller must send the
* contents of this file in <b>auth</b>.
*
* <p>If the 'HashedControlPassword' option is set, <b>auth</b> must contain the salted hash of a
* secret password. The salted hash is computed according to the S2K algorithm in RFC 2440
* (OpenPGP), and prefixed with the s2k specifier. This is then encoded in hexadecimal, prefixed
* by the indicator sequence "16:".
*
* <p>You can generate the salt of a password by calling 'tor --hash-password <password>' or by
* using the provided PasswordDigest class. To authenticate under this scheme, the controller
* sends Tor the original secret that was used to generate the password.
*/
public void authenticate(byte[] auth) throws IOException {
String cmd = "AUTHENTICATE " + Bytes.hex(auth) + "\r\n";
sendAndWaitForResponse(cmd, null);
}
