package com.trilead.ssh2;
/**
* An <code>InteractiveCallback</code> is used to respond to challenges sent
* by the server if authentication mode "keyboard-interactive" is selected.
*
* @see Connection#authenticateWithKeyboardInteractive(String,
* String[], InteractiveCallback)
*
* @author Christian Plattner, plattner@trilead.com
* @version $Id: InteractiveCallback.java,v 1.1 2007/10/15 12:49:56 cplattne Exp $
*/
public interface InteractiveCallback
{
/**
* This callback interface is used during a "keyboard-interactive"
* authentication. Every time the server sends a set of challenges (however,
* most often just one challenge at a time), this callback function will be
* called to give your application a chance to talk to the user and to
* determine the response(s).
* <p>
* Some copy-paste information from the standard: a command line interface
* (CLI) client SHOULD print the name and instruction (if non-empty), adding
* newlines. Then for each prompt in turn, the client SHOULD display the
* prompt and read the user input. The name and instruction fields MAY be
* empty strings, the client MUST be prepared to handle this correctly. The
* prompt field(s) MUST NOT be empty strings.
* <p>
* Please refer to draft-ietf-secsh-auth-kbdinteract-XX.txt for the details.
* <p>
* Note: clients SHOULD use control character filtering as discussed in
* RFC4251 to avoid attacks by including
* terminal control characters in the fields to be displayed.
*
* @param name
* the name String sent by the server.
* @param instruction
* the instruction String sent by the server.
* @param numPrompts
* number of prompts - may be zero (in this case, you should just
* return a String array of length zero).
* @param prompt
* an array (length <code>numPrompts</code>) of Strings
* @param echo
* an array (length <code>numPrompts</code>) of booleans. For
* each prompt, the corresponding echo field indicates whether or
* not the user input should be echoed as characters are typed.
* @return an array of reponses - the array size must match the parameter
* <code>numPrompts</code>.
*/
public String[] replyToChallenge(String name, String instruction, int numPrompts, String[] prompt, boolean[] echo)
throws Exception;
}