ssh2authsshcomsecurid.java

一个非常好的ssh客户端实现

/******************************************************************************
 *
 * Copyright (c) 1999-2003 AppGate Network Security AB. All Rights Reserved.
 * 
 * This file contains Original Code and/or Modifications of Original Code as
 * defined in and that are subject to the MindTerm Public Source License,
 * Version 2.0, (the 'License'). You may not use this file except in compliance
 * with the License.
 * 
 * You should have received a copy of the MindTerm Public Source License
 * along with this software; see the file LICENSE.  If not, write to
 * AppGate Network Security AB, Otterhallegatan 2, SE-41118 Goteborg, SWEDEN
 *
 *****************************************************************************/

package com.mindbright.ssh2;

/**
 * This class implements a module for SecurID authentication as defined by SSH
 * Inc. as the 'local' method '[e-mail]'. It uses the interface
 * <code>SSH2Interactor</code> for all interactions generated in the
 * authentication process. This method is not part of any public standard, it's
 * currently only available with SSH2 servers from SSH Communcations.
 *
 * @see SSH2AuthModule
 * @see SSH2Interactor
 */
public class SSH2AuthSSHComSecurID implements SSH2AuthModule {

    public final static String STANDARD_NAME = "[e-mail]";

    SSH2Interactor interactor;
    String         promptPIN;
    String         promptNext;
    String         promptNew;
    String         promptNew2;
    String         promptSelect;
    String         promptSystem;

    public SSH2AuthSSHComSecurID(SSH2Interactor interactor,
				 String promptPIN,
				 String promptNext,
				 String promptNew,
				 String promptNew2,
				 String promptSelect,
				 String promptSystem)
    {
	this.interactor   = interactor;
	this.promptPIN    = promptPIN;
	this.promptNext   = promptNext;
	this.promptNew    = promptNew;
	this.promptNew2   = promptNew2;
	this.promptSelect = promptSelect;
	this.promptSystem = promptSystem;
    }

    public String getStandardName() {
	return STANDARD_NAME;
    }

    public SSH2TransportPDU processMethodMessage(SSH2UserAuth userAuth,
						 SSH2TransportPDU pdu)
	throws SSH2UserCancelException
    {
	switch(pdu.getType()) {
	case SSH2.MSG_USERAUTH_SECURID_CHALLENGE:
	    pdu = getPasscodeResponse(userAuth, true);
	    break;
	case SSH2.MSG_USERAUTH_SECURID_NEW_PIN_REQD:
	    int     minPinLen      = pdu.readInt();
	    int     maxPinLen      = pdu.readInt();
	    int     userSelectable = pdu.readByte();
	    boolean alphaNumeric   = pdu.readBoolean();
	    String  systemPIN      = pdu.readJavaString();

	    String newPIN = getNewPIN(systemPIN, userSelectable, alphaNumeric,
				      minPinLen, maxPinLen);

	    pdu = createResponse(userAuth, newPIN, true);
	    break;
	default:
	    userAuth.getTransport().getLog().
		warning("SSH2AuthSSHComSecurID",
			"received unexpected packet of type: " + pdu.getType());
	    pdu = null;
	}
	return pdu;
    }

    public SSH2TransportPDU startAuthentication(SSH2UserAuth userAuth)
	throws SSH2UserCancelException
    {
	return getPasscodeResponse(userAuth, false);
    }

    private String getNewPIN(String systemPIN, int userSelectable,
				    boolean alphaNumeric,
				    int minLen, int maxLen)
	throws SSH2UserCancelException
    {
	String newPIN = "";
	String a      = null;
	if(userSelectable == SSH2.SSH_SECURID_USER_SELECTABLE_PIN) {
	    a = interactor.promptLine(promptSelect, true);
	    if(a.equalsIgnoreCase("yes") || a.equalsIgnoreCase("y")) {
		userSelectable = SSH2.SSH_SECURID_MUST_CHOOSE_PIN;
	    } else {
		userSelectable = SSH2.SSH_SECURID_CANNOT_CHOOSE_PIN;
	    }
	}
	if(userSelectable == SSH2.SSH_SECURID_CANNOT_CHOOSE_PIN) {
	    a = interactor.promptLine(promptSystem + systemPIN + " (yes/no)? ",
				      true);
	    if(a.equalsIgnoreCase("yes") || a.equalsIgnoreCase("y")) {
		newPIN = systemPIN;
	    }
	} else if(userSelectable == SSH2.SSH_SECURID_MUST_CHOOSE_PIN) {
	    String[] aa;
	    do {
		aa = interactor.promptMulti(new String[] { promptNew + 
					   " (" + minLen + " - " + maxLen +
					    (alphaNumeric ? "characters" :
					     "digits") + ")", promptNew2 },
					    new boolean[] { false, false });
	    } while(!aa[0].equals(aa[1]));
	    newPIN = aa[0];
	}
	return newPIN;
    }

    private SSH2TransportPDU getPasscodeResponse(SSH2UserAuth userAuth,
						 boolean challenge)
	throws SSH2UserCancelException
    {
	String prompt;
	if(challenge) {
	    prompt = promptNext;
	} else {
	    prompt = promptPIN;
	}

	String pin = interactor.promptLine(prompt, true);

	return createResponse(userAuth, pin, challenge);
    }

    private SSH2TransportPDU createResponse(SSH2UserAuth userAuth,
					    String pin,
					    boolean challenge)
    {
	SSH2TransportPDU pdu =
	    userAuth.createUserAuthRequest(STANDARD_NAME);
	pdu.writeBoolean(challenge);
	pdu.writeString(pin);
	return pdu;
    }

    public void clearSensitiveData()
    {
	// Nothing to do
    }

    public boolean retryPointless() {
        return false;
    }
}