LtpaToken Generator for Multi-server SSO Configurations

/**
 * LtpaToken Generator V1.1
 * 
 * This Java class generates a valid LtpaToken valid for any user name.
 * 
 * To use it on SSJS:
 * -------------------
 * 	importPackage(com.developi.openntf);
 * 	var ltpa:LtpaGenerator=new LtpaGenerator();
 * 	ltpa.initByConfiguration(sessionAsSigner, "Developi:LtpaToken");
 * 	token=ltpa.generateLtpaToken("CN=Serdar Basegmez/O=developi");
 * 
 * To use the token (make sure replace '.developi.info' with your SSO domain):
 * -------------------------------------------------------------------------
 * 	response=facesContext.getExternalContext().getResponse();
 * 	response.setHeader("Set-Cookie", "LtpaToken=" + token + "; domain=.developi.info; path=/");
 * facesContext.getExternalContext().redirect(someUrl);
 * 
 * 1. "Developi:LtpaToken" is the SSO configuration key. If you are using Internet site configuration,  it will be 
 *     "Organization:TokenName". Otherwise, it will be "TokenName" only. You may check "($WebSSOConfigs)"
 *     view in the names.nsf database.
 * 2. sessionAsSigner should be given as parameter to the initByConfiguration method.
 * 3. The signer of the database design should be listed as 'Owner' or 'Administrator' in the SSO configuration.
 * 4. Current version only supports Domino keys. Tokens imported from Websphere will not generate valid tokens.
 * 
 * Important Note:
 * You will see "LMBCS" encoding below. This is because of that Domino encodes user names in LMBCS charset.
 * As long as you use standard ANSI characters, it's OK. However if you use other languages (like Turkish) in
 * user names, it will be encoded in default charset (ISO-8859-1). Normally, Domino JVM does not support LMBCS
 * encoding. So you have to install a supporting library. I have found ICU (International Components for Unicode) library.
 * However, it cannot be attached into NSF. So you have to install it into Domino JVM. To do this;
 * 
 *  - Go to ICU Project site (http://www.icu-project.org)
 *  - Download "icu4j-49_1.jar" and "icu4j-charset-49_1.jar" (or latest versions)
 *  - Put those files into "{Domino Program Folder}\jvm\lib\ext"
 *  - Restart your HTTP task
 * 
 * This will install ICU library into your server. This library is licensed under X-License and can be used commercially.
 * I didn't try but it can also be installed via OSGi plugin. Let me know if you do it :)
 * Direct link for download: http://apps.icu-project.org/icu-jsp/downloadPage.jsp?ver=49.1&base=j&svn=release-49-1
 * 
 */

package com.developi.openntf;

import java.io.UnsupportedEncodingException;
import java.nio.charset.Charset;
import java.security.MessageDigest;
import java.security.NoSuchAlgorithmException;
import java.util.Arrays;
import java.util.GregorianCalendar;

import javax.xml.bind.DatatypeConverter;

import lotus.domino.Database;
import lotus.domino.Document;
import lotus.domino.NotesException;
import lotus.domino.Session;
import lotus.domino.View;

/*
 * @author Serdar Basegmez, Developi (http://lotusnotus.com/en)
 */

public class LtpaGenerator {

	public final String NAMESDB="names.nsf";
	public final String SSOVIEW="($WebSSOConfigs)";
	public final String SSO_DOMINO_SECRETFIELD="LTPA_DominoSecret";
	public final String SSO_DOMINO_DURATIONFIELD="LTPA_TokenExpiration";
	
	private boolean ready=false;

	private int duration=300;
	private String ltpaSecret="";
	
	public LtpaGenerator() {
	}

	public LtpaGenerator(String ltpaSecret) {
		setLtpaSecret(ltpaSecret);
	}

	public LtpaGenerator(String ltpaSecret, int duration) {
		setLtpaSecret(ltpaSecret);
		setDuration(duration);
	}
	
	public void initByConfiguration(Session session, String configName) throws Exception {
		Database dbNames=null;
		View ssoView=null;
		Document ssoDoc=null;
		
		try {
			String currentServer=session.getCurrentDatabase().getServer();
			dbNames=session.getDatabase(currentServer, NAMESDB, false);
			ssoView=dbNames.getView(SSOVIEW);
			ssoDoc=ssoView.getDocumentByKey(configName, true);
			if(ssoDoc==null) {
				throw new IllegalArgumentException("Unable to find SSO configuration with the given configName.");
			}
			
			setLtpaSecret(ssoDoc.getItemValueString(SSO_DOMINO_SECRETFIELD));
			setDuration(ssoDoc.getItemValueInteger(SSO_DOMINO_DURATIONFIELD));
			
		} catch (NotesException ex) {
			throw new Exception("Notes Error: "+ex);
		} finally {
			try {
				if(dbNames!=null) dbNames.recycle();
				if(ssoView!=null) ssoView.recycle();
				if(ssoDoc!=null) ssoDoc.recycle();				
			} catch(NotesException exc) {
				//ignore
			}
		}
	}
	
	public String generateLtpaToken(String userName) {
		if(!isReady()) {
			throw new IllegalStateException("LtpaGenerator is not ready.");
		}
		
		MessageDigest sha1 = null;

		GregorianCalendar creationDate=new GregorianCalendar();
		GregorianCalendar expiringDate=new GregorianCalendar();

		byte[] userNameArray=userName.getBytes();
		
		expiringDate.add(GregorianCalendar.MINUTE, duration);
    
		try {
			sha1 = MessageDigest.getInstance( "SHA-1" );
		} catch (NoSuchAlgorithmException e) {
			e.printStackTrace(System.err);
		}
				
		byte[] secretDecoded=DatatypeConverter.parseBase64Binary(ltpaSecret);

		// Look at important notes above...
		try {
			if(Charset.isSupported("LMBCS")) {
				userNameArray=userName.getBytes("LMBCS");
			}
		} catch (UnsupportedEncodingException e) {
			// Not supposed to fall here.
		}
			
		byte[] tokenBase=concatBytes(("\000\001\002\003"+getHexRep(creationDate)+getHexRep(expiringDate)).getBytes(), userNameArray);
		
		byte[] digest=sha1.digest(concatBytes(tokenBase, secretDecoded));
	
		return DatatypeConverter.printBase64Binary(concatBytes(tokenBase, digest));
		
	}

	public static byte[] concatBytes(byte[] arr1, byte[] arr2) {
		byte[] result=Arrays.copyOf(arr1, arr1.length+arr2.length);
		System.arraycopy(arr2, 0, result, arr1.length, arr2.length);
		return result; 
	}
	
	public static String getHexRep(GregorianCalendar date) {
		int timeVal=(int)(date.getTimeInMillis()/1000);
		String hex=Integer.toHexString(timeVal).toUpperCase();
		
		if(hex.length()>=8) {
			return hex; 
		} else {
			return String.format("%0"+(8-hex.length())+"d", 0)+hex;
		}
	}

	public void setDuration(int duration) {
		this.duration = duration;
	}

	public void setLtpaSecret(String ltpaSecret) {
		this.ltpaSecret = ltpaSecret;
		this.ready=true;
	}

	public boolean isReady() {
		return ready;
	}

}





This Java class generates a valid LtpaToken valid for any user name.

When using, you should sign the database with a user that is listed as 'Owner' or 'Administrator' in the SSO configuration. This version only supports Domino keys. Tokens imported from Websphere will not generate valid tokens. Since WAS token generation is not based on public API, it doesn't seem possible to do it without native libraries.

This class can be used for any customized login operations. You may specify any user with any name while creating the token.

UPDATE on 9th July, 2012:
- LMBCS encoding support has been added (see comments for details)

Java
Serdar Basegmez
May 26, 2012 5:27 PM
Rating
507

All code submitted to OpenNTF XSnippets, whether submitted as a "Snippet" or in the body of a Comment, is provided under the Apache License Version 2.0. See Terms of Use for full details.



4 comment(s)Login first to comment...
an Sharma
(at 09:27 on 23.01.2013)
Simple to use and works great.
Any progress with LtpaToken2? We have Web SSO with imported WebSphere key and LtpaToken does not work on that server.
Any suggestions as how to proceed.
Thimo Jansen
(at 05:05 on 09.08.2012)
Wonderful piece of code, works straight out of the box. Thanks!
Serdar Basegmez
(at 06:51 on 09.07.2012)
Thanks Enrique...

The problem with WAS tokens is that IBM is using a series of non-public encryption/signing algorithms for the token generation. So the only way to generate a valid token seems using native C API calls at the moment.

I'll try some other techniques later...
Enrique M Munoz
(at 04:03 on 03.07.2012)
Hello Mr Basegmez.

Very good work! We are very interested on it. In fact we are looking forward the way you can solve the last part when Websphere token can be added. I offer to you for any help or test.
We are working in a IBMi system with Domino and Websphere but beyond this we are using X.509 Certificates.

Thank you and congrats for your work