/* 
 * @(#)SampleCallbackHandler.java	1.2 01/05/24
 * 
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 * Reserved.
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 */

import javax.security.auth.callback.*;
import java.io.IOException;
import java.io.BufferedReader;
import java.io.InputStreamReader;

/**
 * Demonstrates how to write a callback handler for use with SASL.
 * Used with UseCallback.java, GssExample.java, and Mutual.java.
 *
 * Standalone test: java SampleCallbackHandler
 */
public class SampleCallbackHandler implements CallbackHandler {
    public void handle(Callback[] callbacks) 
	throws java.io.IOException, UnsupportedCallbackException {
	    for (int i = 0; i < callbacks.length; i++) {
		if (callbacks[i] instanceof NameCallback) {
		    NameCallback cb = (NameCallback)callbacks[i];
		    cb.setName(getInput(cb.getPrompt()));

		} else if (callbacks[i] instanceof PasswordCallback) {
		    PasswordCallback cb = (PasswordCallback)callbacks[i];

		    String pw = getInput(cb.getPrompt());
		    char[] passwd = new char[pw.length()];
		    pw.getChars(0, passwd.length, passwd, 0);

		    cb.setPassword(passwd);
		} else {
		    throw new UnsupportedCallbackException(callbacks[i]);
		}
	    }
    }

    /**
     * A reader from Standard Input. In real world apps, this would
     * typically be a TextComponent or similar widget.
     */
    private String getInput(String prompt) throws IOException {
	System.out.print(prompt);
	BufferedReader in = new BufferedReader(
	    new InputStreamReader(System.in));
	return in.readLine();
    }

    public static void main(String[] args) throws IOException,
    UnsupportedCallbackException {

	// Test handler

	CallbackHandler ch = new SampleCallbackHandler();
	Callback[] callbacks = new Callback[]{
	    new NameCallback("user id:"),
		new PasswordCallback("password:", true)};

	ch.handle(callbacks);
    }
}