SSLUtils.java

/*
 * This file is part of FTB Launcher.
 *
 * Copyright © 2012-2016, FTB Launcher Contributors <https://github.com/Slowpoke101/FTBLaunch/>
 * FTB Launcher is licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *  http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
/*
 * Original code from http://nodsw.com/blog/leeland/2006/12/06-no-more-unable-find-valid-certification-path-requested-target
 * Java 7 fix from http://infposs.blogspot.fi/2013/06/installcert-and-java-7.html
 *
 * Adapted code for FTB launcher: removed keychain modification, added more error handling and using launcher's logging system
 */

package net.ftb.util;

import java.io.File;
import java.io.FileInputStream;
import java.io.IOException;
import java.io.InputStream;
import java.net.UnknownHostException;
import java.security.KeyStore;
import java.security.MessageDigest;
import java.security.cert.CertificateException;
import java.security.cert.X509Certificate;

import javax.net.ssl.SSLContext;
import javax.net.ssl.SSLException;
import javax.net.ssl.SSLSocket;
import javax.net.ssl.SSLSocketFactory;
import javax.net.ssl.TrustManager;
import javax.net.ssl.TrustManagerFactory;
import javax.net.ssl.X509TrustManager;

import net.ftb.log.Logger;

public class SSLUtils
{

	/**
	 *
	 * @param s host name to test
	 * @param p port to test
	 * @throws Exception
	 */
	public static void printServerCertChain (String s, int p)
	{
		boolean handshake_failed = false;
		KeyStore ks;
		SSLSocketFactory factory;
		SSLSocket socket;
		SavingTrustManager tm;

		// fill keychain
		char[] passphrase = "changeit".toCharArray();
		char SEP = File.separatorChar;
		File dir = new File(System.getProperty("java.home") + SEP + "lib" + SEP + "security");
		File file = new File(dir, "cacerts");
		try
		{
			InputStream in = new FileInputStream(file);
			ks = KeyStore.getInstance(KeyStore.getDefaultType());
			ks.load(in, passphrase);
			in.close();
		}
		catch (Exception e)
		{
			Logger.logWarn("Keychain loadign failed", e);
			return;
		}

		// prepare SSL
		try
		{
			SSLContext context = SSLContext.getInstance("TLS");
			TrustManagerFactory tmf = TrustManagerFactory.getInstance(TrustManagerFactory.getDefaultAlgorithm());
			tmf.init(ks);
			X509TrustManager defaultTrustManager = (X509TrustManager)tmf.getTrustManagers()[0];
			tm = new SavingTrustManager(defaultTrustManager);
			context.init(null, new TrustManager[]
				{tm}, null);
			factory = context.getSocketFactory();
		}
		catch (Exception e)
		{
			Logger.logWarn("SSL preparation failed", e);
			return;
		}

		// open socket
		try
		{
			socket = (SSLSocket)factory.createSocket(s, p);
			socket.setSoTimeout(10000);
		}
		catch (UnknownHostException e)
		{
			Logger.logWarn("Host lookup failed", e);
			return;
		}
		catch (Exception e)
		{
			Logger.logWarn("Generic socket fail", e);
			return;
		}

		// and finally initiate SSL handshake
		try
		{
			socket.startHandshake();
			socket.close();
			Logger.logDebug("SSL handshake was succesfull. Printing certificate chain...");
		}
		catch (SSLException e)
		{
			handshake_failed = true;
		}
		catch (IOException e)
		{
			Logger.logWarn("IOException", e);
			return;
		}

		X509Certificate[] chain = tm.chain;
		if (chain == null)
		{
			Logger.logDebug("Could not obtain server certificate chain");
			return;
		}

		if (handshake_failed)
		{
			Logger.logError("SSL handshake failed. Something might be altering SSL certificates");
			Logger.logError("Certificates are not trusted by JVM certificate chain");
			Logger.logError("Certificate chain will be printed in debug logging level");
		}

		Logger.logDebug("");
		Logger.logDebug("Server sent " + chain.length + " certificate(s):");

		Logger.logDebug("");
		try
		{
			MessageDigest sha1 = MessageDigest.getInstance("SHA1");
			MessageDigest md5 = MessageDigest.getInstance("MD5");
			for(int i = 0; i < chain.length; i++)
			{
				X509Certificate cert = chain[i];
				Logger.logDebug(" " + (i + 1) + " Subject " + cert.getSubjectDN());
				Logger.logDebug("   Issuer  " + cert.getIssuerDN());
				sha1.update(cert.getEncoded());
				Logger.logDebug("   sha1    " + toHexString(sha1.digest()));
				md5.update(cert.getEncoded());
				Logger.logDebug("   md5     " + toHexString(md5.digest()));
				Logger.logDebug("");
			}
		}
		catch (Exception e)
		{
			Logger.logDebug("Certificate printing failed", e);
		}

	}

	private static final char[] HEXDIGITS = "0123456789abcdef".toCharArray();

	private static String toHexString (byte[] bytes)
	{
		StringBuilder sb = new StringBuilder(bytes.length * 3);
		for(int b : bytes)
		{
			b &= 0xff;
			sb.append(HEXDIGITS[b >> 4]);
			sb.append(HEXDIGITS[b & 15]);
			sb.append(' ');
		}
		return sb.toString();
	}

	private static class SavingTrustManager implements X509TrustManager
	{

		private final X509TrustManager tm;
		private X509Certificate[] chain;

		SavingTrustManager (final X509TrustManager tm)
		{
			this.tm = tm;
		}

		@Override
		public X509Certificate[] getAcceptedIssuers ()
		{
			return new X509Certificate[0];
			// throw new UnsupportedOperationException();
		}

		@Override
		public void checkClientTrusted (final X509Certificate[] chain, final String authType) throws CertificateException
		{
			throw new UnsupportedOperationException();
		}

		@Override
		public void checkServerTrusted (final X509Certificate[] chain, final String authType) throws CertificateException
		{
			this.chain = chain;
			this.tm.checkServerTrusted(chain, authType);
		}
	}
}