proxyutilities.java

The source code for this package is located in src/gov/nist/sip/proxy. The proxy is a pure JAIN-SIP

package gov.nist.sip.proxy;

import java.util.*;
import javax.sip.*;
import javax.sip.message.*;
import javax.sip.header.*;
import java.security.MessageDigest;
import java.security.NoSuchAlgorithmException;
import javax.sip.address.*;

import org.apache.log4j.Logger;

/**
 * Utilities for the proxy.
 * 
 * @version JAIN-SIP-1.2
 * 
 * @author Olvier Deruelle <[e-mail]> <br/>
 * @author M. Ranganathan <[e-mail]> <br/> <a href="{@docRoot}/uncopyright.html">This
 *         code is in the public domain.</a>
 * 
 */
public class ProxyUtilities {

	private static Logger logger = Logger.getLogger(ProxyUtilities.class);

	protected Proxy proxy;

	public static final String BRANCH_MAGIC_COOKIE = "z9hG4bK";

	protected ProxyUtilities(Proxy proxy) {
		this.proxy = proxy;
	}

	/**
	 * Generate a cryptographically random identifier that can be used to
	 * generate a branch identifier.
	 * 
	 * @return a cryptographically random gloablly unique string that can be
	 *         used as a branch identifier.
	 */
	public static String generateBranchId() {
		String b = new Integer((int) (Math.random() * 10000)).toString()
				+ System.currentTimeMillis();
		try {
			MessageDigest messageDigest = MessageDigest.getInstance("MD5");
			byte bid[] = messageDigest.digest(b.getBytes());
			// cryptographically random string.
			// prepend with a magic cookie to indicate we
			// are bis09 compatible.
			return BRANCH_MAGIC_COOKIE + toHexString(bid);
		} catch (NoSuchAlgorithmException ex) {

			return null;
		}
	}

	/**
	 * to hex converter
	 */
	private static final char[] toHex = { '0', '1', '2', '3', '4', '5', '6',
			'7', '8', '9', 'a', 'b', 'c', 'd', 'e', 'f' };

	/**
	 * convert an array of bytes to an hexadecimal string
	 * 
	 * @return a string
	 * @param b
	 *            bytes array to convert to a hexadecimal string
	 */

	public static String toHexString(byte b[]) {
		int pos = 0;
		char[] c = new char[b.length * 2];
		for (int i = 0; i < b.length; i++) {
			c[pos++] = toHex[(b[i] >> 4) & 0x0F];
			c[pos++] = toHex[b[i] & 0x0f];
		}
		return new String(c);
	}

	public static String generateTag() {
		return new Integer((int) (Math.random() * 10000)).toString();
	}

	protected boolean matchProxyAddress(Request request) throws Exception {
		javax.sip.address.URI uri = request.getRequestURI();
		SipStack sipStack = proxy.getSipStack();
		if (uri == null)
			return false;
		else {
			SipURI sipURI = ((SipURI) uri);

			String stackIPAddress = sipStack.getIPAddress();
			String host = sipURI.getHost();

			return stackIPAddress.equals(host);

		}
	}

	public static int length(Message message) {
		int cpt = 0;
		try {
			ListIterator l = message.getHeaders(ViaHeader.NAME);
			while (l.hasNext()) {
				l.next();
				cpt++;
			}
			return cpt;
		} catch (Exception e) {
			return cpt;
		}
	}

	public static boolean hasTopViaHeaderProxy(SipStack sipStack,
			Message message) {
		ListIterator viaList = message.getHeaders(ViaHeader.NAME);
		if (viaList == null || length(message) == 0)
			return false;

		String stackIPAddress = sipStack.getIPAddress();
		ViaHeader viaHeader = (ViaHeader) viaList.next();

		if (viaHeader.getHost().equals(stackIPAddress)) {
			Iterator lps = sipStack.getListeningPoints();
			while (lps != null && lps.hasNext()) {
				ListeningPoint lp = (ListeningPoint) lps.next();
				int port = lp.getPort();
				if (viaHeader.getPort() == port)
					return true;
			}
		}
		return false;
	}

	public static void printTransaction(Transaction transaction) {
		if (transaction == null) {
			logger.debug("DEBUG TRANSACTION INFO: the transaction is null ");
			return;
		}

		if (transaction instanceof ServerTransaction) {
			ServerTransaction serverTransaction = (ServerTransaction) transaction;
			logger.debug("DEBUG TRANSACTION INFO: here is the "
					+ " server transaction: " + serverTransaction);

			logger.debug("DEBUG INFO: Its dialog is: "
					+ serverTransaction.getDialog());
		} else if (transaction instanceof ClientTransaction) {
			ClientTransaction clientTransaction = (ClientTransaction) transaction;
			logger.debug("DEBUG TRANSACTION INFO: here is the "
					+ " client transaction: " + clientTransaction);

			logger.debug("DEBUG TRANSACTION INFO: Its dialog is: "
					+ clientTransaction.getDialog());
		}
	}

}