Subtree merged in MemorizingTrustManager

4 files changed, 871 insertions, 0 deletions

diff --git a/libs/MemorizingTrustManager b/libs/MemorizingTrustManager
deleted file mode 160000
-Subproject fad835037adc1bd313bb56b694426fca4eb6734
diff --git a/libs/MemorizingTrustManager/src/de/duenndns/ssl/MTMDecision.java b/libs/MemorizingTrustManager/src/de/duenndns/ssl/MTMDecision.java
new file mode 100644
index 00000000..0efe6b51
--- /dev/null
+++ b/libs/MemorizingTrustManager/src/de/duenndns/ssl/MTMDecision.java
@@ -0,0 +1,33 @@
+/* MemorizingTrustManager - a TrustManager which asks the user about invalid
+ *  certificates and memorizes their decision.
+ *
+ * Copyright (c) 2010 Georg Lukas <georg@op-co.de>
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ * THE SOFTWARE.
+ */
+package de.duenndns.ssl;
+
+class MTMDecision {
+	public final static int DECISION_INVALID	= 0;
+	public final static int DECISION_ABORT		= 1;
+	public final static int DECISION_ONCE		= 2;
+	public final static int DECISION_ALWAYS	= 3;
+
+	int state = DECISION_INVALID;
+}
diff --git a/libs/MemorizingTrustManager/src/de/duenndns/ssl/MemorizingActivity.java b/libs/MemorizingTrustManager/src/de/duenndns/ssl/MemorizingActivity.java
new file mode 100644
index 00000000..013ac29b
--- /dev/null
+++ b/libs/MemorizingTrustManager/src/de/duenndns/ssl/MemorizingActivity.java
@@ -0,0 +1,103 @@
+/* MemorizingTrustManager - a TrustManager which asks the user about invalid
+ *  certificates and memorizes their decision.
+ *
+ * Copyright (c) 2010 Georg Lukas <georg@op-co.de>
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ * THE SOFTWARE.
+ */
+package de.duenndns.ssl;
+
+
+import java.util.logging.Level;
+import java.util.logging.Logger;
+
+import android.app.Activity;
+import android.app.AlertDialog;
+import android.content.DialogInterface;
+import android.content.DialogInterface.*;
+import android.content.Intent;
+import android.os.Bundle;
+
+public class MemorizingActivity extends Activity
+		implements OnClickListener,OnCancelListener {
+
+	private final static Logger LOGGER = Logger.getLogger(MemorizingActivity.class.getName());
+
+	int decisionId;
+
+	AlertDialog dialog;
+	
+	@Override
+	public void onCreate(Bundle savedInstanceState) {
+		LOGGER.log(Level.FINE, "onCreate");
+		super.onCreate(savedInstanceState);
+	}
+
+	@Override
+	public void onResume() {
+		super.onResume();
+		Intent i = getIntent();
+		decisionId = i.getIntExtra(MemorizingTrustManager.DECISION_INTENT_ID, MTMDecision.DECISION_INVALID);
+		int titleId = i.getIntExtra(MemorizingTrustManager.DECISION_TITLE_ID, R.string.mtm_accept_cert);
+		String cert = i.getStringExtra(MemorizingTrustManager.DECISION_INTENT_CERT);
+		LOGGER.log(Level.FINE, "onResume with " + i.getExtras() + " decId=" + decisionId + " data: " + i.getData());
+		dialog = new AlertDialog.Builder(this).setTitle(titleId)
+			.setMessage(cert)
+			.setPositiveButton(R.string.mtm_decision_always, this)
+			.setNeutralButton(R.string.mtm_decision_once, this)
+			.setNegativeButton(R.string.mtm_decision_abort, this)
+			.setOnCancelListener(this)
+			.create();
+		dialog.show();
+	}
+
+	@Override
+	protected void onPause() {
+		if (dialog.isShowing())
+			dialog.dismiss();
+		super.onPause();
+	}
+
+	void sendDecision(int decision) {
+		LOGGER.log(Level.FINE, "Sending decision: " + decision);
+		MemorizingTrustManager.interactResult(decisionId, decision);
+		finish();
+	}
+
+	// react on AlertDialog button press
+	public void onClick(DialogInterface dialog, int btnId) {
+		int decision;
+		dialog.dismiss();
+		switch (btnId) {
+		case DialogInterface.BUTTON_POSITIVE:
+			decision = MTMDecision.DECISION_ALWAYS;
+			break;
+		case DialogInterface.BUTTON_NEUTRAL:
+			decision = MTMDecision.DECISION_ONCE;
+			break;
+		default:
+			decision = MTMDecision.DECISION_ABORT;
+		}
+		sendDecision(decision);
+	}
+
+	public void onCancel(DialogInterface dialog) {
+		sendDecision(MTMDecision.DECISION_ABORT);
+	}
+}
diff --git a/libs/MemorizingTrustManager/src/de/duenndns/ssl/MemorizingTrustManager.java b/libs/MemorizingTrustManager/src/de/duenndns/ssl/MemorizingTrustManager.java
new file mode 100644
index 00000000..9032ba25
--- /dev/null
+++ b/libs/MemorizingTrustManager/src/de/duenndns/ssl/MemorizingTrustManager.java
@@ -0,0 +1,735 @@
+/* MemorizingTrustManager - a TrustManager which asks the user about invalid
+ *  certificates and memorizes their decision.
+ *
+ * Copyright (c) 2010 Georg Lukas <georg@op-co.de>
+ *
+ * MemorizingTrustManager.java contains the actual trust manager and interface
+ * code to create a MemorizingActivity and obtain the results.
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ * THE SOFTWARE.
+ */
+package de.duenndns.ssl;
+
+import android.app.Activity;
+import android.app.Application;
+import android.app.Notification;
+import android.app.NotificationManager;
+import android.app.Service;
+import android.app.PendingIntent;
+import android.content.Context;
+import android.content.Intent;
+import android.net.Uri;
+import android.util.SparseArray;
+import android.os.Handler;
+
+import java.io.File;
+import java.io.IOException;
+import java.security.cert.*;
+import java.security.KeyStore;
+import java.security.KeyStoreException;
+import java.security.MessageDigest;
+import java.util.logging.Level;
+import java.util.logging.Logger;
+import java.text.SimpleDateFormat;
+import java.util.Collection;
+import java.util.Enumeration;
+import java.util.List;
+import java.util.Locale;
+
+import javax.net.ssl.HostnameVerifier;
+import javax.net.ssl.SSLSession;
+import javax.net.ssl.TrustManager;
+import javax.net.ssl.TrustManagerFactory;
+import javax.net.ssl.X509TrustManager;
+
+/**
+ * A X509 trust manager implementation which asks the user about invalid
+ * certificates and memorizes their decision.
+ * <p>
+ * The certificate validity is checked using the system default X509
+ * TrustManager, creating a query Dialog if the check fails.
+ * <p>
+ * <b>WARNING:</b> This only works if a dedicated thread is used for
+ * opening sockets!
+ */
+public class MemorizingTrustManager implements X509TrustManager {
+	final static String DECISION_INTENT = "de.duenndns.ssl.DECISION";
+	final static String DECISION_INTENT_ID     = DECISION_INTENT + ".decisionId";
+	final static String DECISION_INTENT_CERT   = DECISION_INTENT + ".cert";
+	final static String DECISION_INTENT_CHOICE = DECISION_INTENT + ".decisionChoice";
+
+	private final static Logger LOGGER = Logger.getLogger(MemorizingTrustManager.class.getName());
+	final static String DECISION_TITLE_ID      = DECISION_INTENT + ".titleId";
+	private final static int NOTIFICATION_ID = 100509;
+
+	final static String NO_TRUST_ANCHOR = "Trust anchor for certification path not found.";
+	
+	static String KEYSTORE_DIR = "KeyStore";
+	static String KEYSTORE_FILE = "KeyStore.bks";
+
+	Context master;
+	Activity foregroundAct;
+	NotificationManager notificationManager;
+	private static int decisionId = 0;
+	private static SparseArray<MTMDecision> openDecisions = new SparseArray<MTMDecision>();
+
+	Handler masterHandler;
+	private File keyStoreFile;
+	private KeyStore appKeyStore;
+	private X509TrustManager defaultTrustManager;
+	private X509TrustManager appTrustManager;
+
+	/** Creates an instance of the MemorizingTrustManager class that falls back to a custom TrustManager.
+	 *
+	 * You need to supply the application context. This has to be one of:
+	 *    - Application
+	 *    - Activity
+	 *    - Service
+	 *
+	 * The context is used for file management, to display the dialog /
+	 * notification and for obtaining translated strings.
+	 *
+	 * @param m Context for the application.
+	 * @param defaultTrustManager Delegate trust management to this TM. If null, the user must accept every certificate.
+	 */
+	public MemorizingTrustManager(Context m, X509TrustManager defaultTrustManager) {
+		init(m);
+		this.appTrustManager = getTrustManager(appKeyStore);
+		this.defaultTrustManager = defaultTrustManager;
+	}
+
+	/** Creates an instance of the MemorizingTrustManager class using the system X509TrustManager.
+	 *
+	 * You need to supply the application context. This has to be one of:
+	 *    - Application
+	 *    - Activity
+	 *    - Service
+	 *
+	 * The context is used for file management, to display the dialog /
+	 * notification and for obtaining translated strings.
+	 *
+	 * @param m Context for the application.
+	 */
+	public MemorizingTrustManager(Context m) {
+		init(m);
+		this.appTrustManager = getTrustManager(appKeyStore);
+		this.defaultTrustManager = getTrustManager(null);
+	}
+
+	void init(Context m) {
+		master = m;
+		masterHandler = new Handler(m.getMainLooper());
+		notificationManager = (NotificationManager)master.getSystemService(Context.NOTIFICATION_SERVICE);
+
+		Application app;
+		if (m instanceof Application) {
+			app = (Application)m;
+		} else if (m instanceof Service) {
+			app = ((Service)m).getApplication();
+		} else if (m instanceof Activity) {
+			app = ((Activity)m).getApplication();
+		} else throw new ClassCastException("MemorizingTrustManager context must be either Activity or Service!");
+
+		File dir = app.getDir(KEYSTORE_DIR, Context.MODE_PRIVATE);
+		keyStoreFile = new File(dir + File.separator + KEYSTORE_FILE);
+
+		appKeyStore = loadAppKeyStore();
+	}
+
+	
+	/**
+	 * Returns a X509TrustManager list containing a new instance of
+	 * TrustManagerFactory.
+	 *
+	 * This function is meant for convenience only. You can use it
+	 * as follows to integrate TrustManagerFactory for HTTPS sockets:
+	 *
+	 * <pre>
+	 *     SSLContext sc = SSLContext.getInstance("TLS");
+	 *     sc.init(null, MemorizingTrustManager.getInstanceList(this),
+	 *         new java.security.SecureRandom());
+	 *     HttpsURLConnection.setDefaultSSLSocketFactory(sc.getSocketFactory());
+	 * </pre>
+	 * @param c Activity or Service to show the Dialog / Notification
+	 */
+	public static X509TrustManager[] getInstanceList(Context c) {
+		return new X509TrustManager[] { new MemorizingTrustManager(c) };
+	}
+
+	/**
+	 * Binds an Activity to the MTM for displaying the query dialog.
+	 *
+	 * This is useful if your connection is run from a service that is
+	 * triggered by user interaction -- in such cases the activity is
+	 * visible and the user tends to ignore the service notification.
+	 *
+	 * You should never have a hidden activity bound to MTM! Use this
+	 * function in onResume() and @see unbindDisplayActivity in onPause().
+	 *
+	 * @param act Activity to be bound
+	 */
+	public void bindDisplayActivity(Activity act) {
+		foregroundAct = act;
+	}
+
+	/**
+	 * Removes an Activity from the MTM display stack.
+	 *
+	 * Always call this function when the Activity added with
+	 * {@link #bindDisplayActivity(Activity)} is hidden.
+	 *
+	 * @param act Activity to be unbound
+	 */
+	public void unbindDisplayActivity(Activity act) {
+		// do not remove if it was overridden by a different activity
+		if (foregroundAct == act)
+			foregroundAct = null;
+	}
+
+	/**
+	 * Changes the path for the KeyStore file.
+	 *
+	 * The actual filename relative to the app's directory will be
+	 * <code>app_<i>dirname</i>/<i>filename</i></code>.
+	 *
+	 * @param dirname directory to store the KeyStore.
+	 * @param filename file name for the KeyStore.
+	 */
+	public static void setKeyStoreFile(String dirname, String filename) {
+		KEYSTORE_DIR = dirname;
+		KEYSTORE_FILE = filename;
+	}
+
+	/**
+	 * Get a list of all certificate aliases stored in MTM.
+	 *
+	 * @return an {@link Enumeration} of all certificates
+	 */
+	public Enumeration<String> getCertificates() {
+		try {
+			return appKeyStore.aliases();
+		} catch (KeyStoreException e) {
+			// this should never happen, however...
+			throw new RuntimeException(e);
+		}
+	}
+
+	/**
+	 * Get a certificate for a given alias.
+	 *
+	 * @param alias the certificate's alias as returned by {@link #getCertificates()}.
+	 *
+	 * @return the certificate associated with the alias or <tt>null</tt> if none found.
+	 */
+	public Certificate getCertificate(String alias) {
+		try {
+			return appKeyStore.getCertificate(alias);
+		} catch (KeyStoreException e) {
+			// this should never happen, however...
+			throw new RuntimeException(e);
+		}
+	}
+
+	/**
+	 * Removes the given certificate from MTMs key store.
+	 *
+	 * <p>
+	 * <b>WARNING</b>: this does not immediately invalidate the certificate. It is
+	 * well possible that (a) data is transmitted over still existing connections or
+	 * (b) new connections are created using TLS renegotiation, without a new cert
+	 * check.
+	 * </p>
+	 * @param alias the certificate's alias as returned by {@link #getCertificates()}.
+	 *
+	 * @throws KeyStoreException if the certificate could not be deleted.
+	 */
+	public void deleteCertificate(String alias) throws KeyStoreException {
+		appKeyStore.deleteEntry(alias);
+		keyStoreUpdated();
+	}
+
+	/**
+	 * Creates a new hostname verifier supporting user interaction.
+	 *
+	 * <p>This method creates a new {@link HostnameVerifier} that is bound to
+	 * the given instance of {@link MemorizingTrustManager}, and leverages an
+	 * existing {@link HostnameVerifier}. The returned verifier performs the
+	 * following steps, returning as soon as one of them succeeds:
+	 *  </p>
+	 *  <ol>
+	 *  <li>Success, if the wrapped defaultVerifier accepts the certificate.</li>
+	 *  <li>Success, if the server certificate is stored in the keystore under the given hostname.</li>
+	 *  <li>Ask the user and return accordingly.</li>
+	 *  <li>Failure on exception.</li>
+	 *  </ol>
+	 *
+	 * @param defaultVerifier the {@link HostnameVerifier} that should perform the actual check
+	 * @return a new hostname verifier using the MTM's key store
+	 *
+	 * @throws IllegalArgumentException if the defaultVerifier parameter is null
+	 */
+	public HostnameVerifier wrapHostnameVerifier(final HostnameVerifier defaultVerifier) {
+		if (defaultVerifier == null)
+			throw new IllegalArgumentException("The default verifier may not be null");
+		
+		return new MemorizingHostnameVerifier(defaultVerifier);
+	}
+	
+	public HostnameVerifier wrapHostnameVerifierNonInteractive(final HostnameVerifier defaultVerifier) {
+		if (defaultVerifier == null)
+			throw new IllegalArgumentException("The default verifier may not be null");
+		
+		return new NonInteractiveMemorizingHostnameVerifier(defaultVerifier);
+	}
+	
+	X509TrustManager getTrustManager(KeyStore ks) {
+		try {
+			TrustManagerFactory tmf = TrustManagerFactory.getInstance("X509");
+			tmf.init(ks);
+			for (TrustManager t : tmf.getTrustManagers()) {
+				if (t instanceof X509TrustManager) {
+					return (X509TrustManager)t;
+				}
+			}
+		} catch (Exception e) {
+			// Here, we are covering up errors. It might be more useful
+			// however to throw them out of the constructor so the
+			// embedding app knows something went wrong.
+			LOGGER.log(Level.SEVERE, "getTrustManager(" + ks + ")", e);
+		}
+		return null;
+	}
+
+	KeyStore loadAppKeyStore() {
+		KeyStore ks;
+		try {
+			ks = KeyStore.getInstance(KeyStore.getDefaultType());
+		} catch (KeyStoreException e) {
+			LOGGER.log(Level.SEVERE, "getAppKeyStore()", e);
+			return null;
+		}
+		try {
+			ks.load(null, null);
+			ks.load(new java.io.FileInputStream(keyStoreFile), "MTM".toCharArray());
+		} catch (java.io.FileNotFoundException e) {
+			LOGGER.log(Level.INFO, "getAppKeyStore(" + keyStoreFile + ") - file does not exist");
+		} catch (Exception e) {
+			LOGGER.log(Level.SEVERE, "getAppKeyStore(" + keyStoreFile + ")", e);
+		}
+		return ks;
+	}
+
+	void storeCert(String alias, Certificate cert) {
+		try {
+			appKeyStore.setCertificateEntry(alias, cert);
+		} catch (KeyStoreException e) {
+			LOGGER.log(Level.SEVERE, "storeCert(" + cert + ")", e);
+			return;
+		}		
+		keyStoreUpdated();
+	}
+	
+	void storeCert(X509Certificate cert) {
+		storeCert(cert.getSubjectDN().toString(), cert);
+	}
+
+	void keyStoreUpdated() {
+		// reload appTrustManager
+		appTrustManager = getTrustManager(appKeyStore);
+
+		// store KeyStore to file
+		java.io.FileOutputStream fos = null;
+		try {
+			fos = new java.io.FileOutputStream(keyStoreFile);
+			appKeyStore.store(fos, "MTM".toCharArray());
+		} catch (Exception e) {
+			LOGGER.log(Level.SEVERE, "storeCert(" + keyStoreFile + ")", e);
+		} finally {
+			if (fos != null) {
+				try {
+					fos.close();
+				} catch (IOException e) {
+					LOGGER.log(Level.SEVERE, "storeCert(" + keyStoreFile + ")", e);
+				}
+			}
+		}
+	}
+
+	// if the certificate is stored in the app key store, it is considered "known"
+	private boolean isCertKnown(X509Certificate cert) {
+		try {
+			return appKeyStore.getCertificateAlias(cert) != null;
+		} catch (KeyStoreException e) {
+			return false;
+		}
+	}
+
+	private boolean isExpiredException(Throwable e) {
+		do {
+			if (e instanceof CertificateExpiredException)
+				return true;
+			e = e.getCause();
+		} while (e != null);
+		return false;
+	}
+
+	public void checkCertTrusted(X509Certificate[] chain, String authType, boolean isServer, boolean interactive)
+		throws CertificateException
+	{
+		LOGGER.log(Level.FINE, "checkCertTrusted(" + chain + ", " + authType + ", " + isServer + ")");
+		try {
+			LOGGER.log(Level.FINE, "checkCertTrusted: trying appTrustManager");
+			if (isServer)
+				appTrustManager.checkServerTrusted(chain, authType);
+			else
+				appTrustManager.checkClientTrusted(chain, authType);
+		} catch (CertificateException ae) {
+			LOGGER.log(Level.FINER, "checkCertTrusted: appTrustManager failed", ae);
+			// if the cert is stored in our appTrustManager, we ignore expiredness
+			if (isExpiredException(ae)) {
+				LOGGER.log(Level.INFO, "checkCertTrusted: accepting expired certificate from keystore");
+				return;
+			}
+			if (isCertKnown(chain[0])) {
+				LOGGER.log(Level.INFO, "checkCertTrusted: accepting cert already stored in keystore");
+				return;
+			}
+			try {
+				if (defaultTrustManager == null)
+					throw ae;
+				LOGGER.log(Level.FINE, "checkCertTrusted: trying defaultTrustManager");
+				if (isServer)
+					defaultTrustManager.checkServerTrusted(chain, authType);
+				else
+					defaultTrustManager.checkClientTrusted(chain, authType);
+			} catch (CertificateException e) {
+				e.printStackTrace();
+				if (interactive) {
+					interactCert(chain, authType, e);
+				} else {
+					throw e;
+				}
+			}
+		}
+	}
+
+	public void checkClientTrusted(X509Certificate[] chain, String authType)
+		throws CertificateException
+	{
+		checkCertTrusted(chain, authType, false,true);
+	}
+
+	public void checkServerTrusted(X509Certificate[] chain, String authType)
+		throws CertificateException
+	{
+		checkCertTrusted(chain, authType, true,true);
+	}
+
+	public X509Certificate[] getAcceptedIssuers()
+	{
+		LOGGER.log(Level.FINE, "getAcceptedIssuers()");
+		return defaultTrustManager.getAcceptedIssuers();
+	}
+
+	private int createDecisionId(MTMDecision d) {
+		int myId;
+		synchronized(openDecisions) {
+			myId = decisionId;
+			openDecisions.put(myId, d);
+			decisionId += 1;
+		}
+		return myId;
+	}
+
+	private static String hexString(byte[] data) {
+		StringBuffer si = new StringBuffer();
+		for (int i = 0; i < data.length; i++) {
+			si.append(String.format("%02x", data[i]));
+			if (i < data.length - 1)
+				si.append(":");
+		}
+		return si.toString();
+	}
+
+	private static String certHash(final X509Certificate cert, String digest) {
+		try {
+			MessageDigest md = MessageDigest.getInstance(digest);
+			md.update(cert.getEncoded());
+			return hexString(md.digest());
+		} catch (java.security.cert.CertificateEncodingException e) {
+			return e.getMessage();
+		} catch (java.security.NoSuchAlgorithmException e) {
+			return e.getMessage();
+		}
+	}
+
+	private void certDetails(StringBuffer si, X509Certificate c) {
+		SimpleDateFormat validityDateFormater = new SimpleDateFormat("yyyy-MM-dd");
+		si.append("\n");
+		si.append(c.getSubjectDN().toString());
+		si.append("\n");
+		si.append(validityDateFormater.format(c.getNotBefore()));
+		si.append(" - ");
+		si.append(validityDateFormater.format(c.getNotAfter()));
+		si.append("\nSHA-256: ");
+		si.append(certHash(c, "SHA-256"));
+		si.append("\nSHA-1: ");
+		si.append(certHash(c, "SHA-1"));
+		si.append("\nSigned by: ");
+		si.append(c.getIssuerDN().toString());
+		si.append("\n");
+	}
+	
+	private String certChainMessage(final X509Certificate[] chain, CertificateException cause) {
+		Throwable e = cause;
+		LOGGER.log(Level.FINE, "certChainMessage for " + e);
+		StringBuffer si = new StringBuffer();
+		if (e.getCause() != null) {
+			e = e.getCause();
+			// HACK: there is no sane way to check if the error is a "trust anchor
+			// not found", so we use string comparison.
+			if (NO_TRUST_ANCHOR.equals(e.getMessage())) {
+				si.append(master.getString(R.string.mtm_trust_anchor));
+			} else
+				si.append(e.getLocalizedMessage());
+			si.append("\n");
+		}
+		si.append("\n");
+		si.append(master.getString(R.string.mtm_connect_anyway));
+		si.append("\n\n");
+		si.append(master.getString(R.string.mtm_cert_details));
+		for (X509Certificate c : chain) {
+			certDetails(si, c);
+		}
+		return si.toString();
+	}
+
+	private String hostNameMessage(X509Certificate cert, String hostname) {
+		StringBuffer si = new StringBuffer();
+
+		si.append(master.getString(R.string.mtm_hostname_mismatch, hostname));
+		si.append("\n\n");
+		try {
+			Collection<List<?>> sans = cert.getSubjectAlternativeNames();
+			if (sans == null) {
+				si.append(cert.getSubjectDN());
+				si.append("\n");
+			} else for (List<?> altName : sans) {
+				Object name = altName.get(1);
+				if (name instanceof String) {
+					si.append("[");
+					si.append((Integer)altName.get(0));
+					si.append("] ");
+					si.append(name);
+					si.append("\n");
+				}
+			}
+		} catch (CertificateParsingException e) {
+			e.printStackTrace();
+			si.append("<Parsing error: ");
+			si.append(e.getLocalizedMessage());
+			si.append(">\n");
+		}
+		si.append("\n");
+		si.append(master.getString(R.string.mtm_connect_anyway));
+		si.append("\n\n");
+		si.append(master.getString(R.string.mtm_cert_details));
+		certDetails(si, cert);
+		return si.toString();
+	}
+
+	// We can use Notification.Builder once MTM's minSDK is >= 11
+	@SuppressWarnings("deprecation")
+	void startActivityNotification(Intent intent, int decisionId, String certName) {
+		Notification n = new Notification(android.R.drawable.ic_lock_lock,
+				master.getString(R.string.mtm_notification),
+				System.currentTimeMillis());
+		PendingIntent call = PendingIntent.getActivity(master, 0, intent, 0);
+		n.setLatestEventInfo(master.getApplicationContext(),
+				master.getString(R.string.mtm_notification),
+				certName, call);
+		n.flags |= Notification.FLAG_AUTO_CANCEL;
+
+		notificationManager.notify(NOTIFICATION_ID + decisionId, n);
+	}
+
+	/**
+	 * Returns the top-most entry of the activity stack.
+	 *
+	 * @return the Context of the currently bound UI or the master context if none is bound
+	 */
+	Context getUI() {
+		return (foregroundAct != null) ? foregroundAct : master;
+	}
+
+	int interact(final String message, final int titleId) {
+		/* prepare the MTMDecision blocker object */
+		MTMDecision choice = new MTMDecision();
+		final int myId = createDecisionId(choice);
+
+		masterHandler.post(new Runnable() {
+			public void run() {
+				Intent ni = new Intent(master, MemorizingActivity.class);
+				ni.setFlags(Intent.FLAG_ACTIVITY_NEW_TASK);
+				ni.setData(Uri.parse(MemorizingTrustManager.class.getName() + "/" + myId));
+				ni.putExtra(DECISION_INTENT_ID, myId);
+				ni.putExtra(DECISION_INTENT_CERT, message);
+				ni.putExtra(DECISION_TITLE_ID, titleId);
+
+				// we try to directly start the activity and fall back to
+				// making a notification
+				try {
+					getUI().startActivity(ni);
+				} catch (Exception e) {
+					LOGGER.log(Level.FINE, "startActivity(MemorizingActivity)", e);
+					startActivityNotification(ni, myId, message);
+				}
+			}
+		});
+
+		LOGGER.log(Level.FINE, "openDecisions: " + openDecisions + ", waiting on " + myId);
+		try {
+			synchronized(choice) { choice.wait(); }
+		} catch (InterruptedException e) {
+			LOGGER.log(Level.FINER, "InterruptedException", e);
+		}
+		LOGGER.log(Level.FINE, "finished wait on " + myId + ": " + choice.state);
+		return choice.state;
+	}
+	
+	void interactCert(final X509Certificate[] chain, String authType, CertificateException cause)
+			throws CertificateException
+	{
+		switch (interact(certChainMessage(chain, cause), R.string.mtm_accept_cert)) {
+		case MTMDecision.DECISION_ALWAYS:
+			storeCert(chain[0]); // only store the server cert, not the whole chain
+		case MTMDecision.DECISION_ONCE:
+			break;
+		default:
+			throw (cause);
+		}
+	}
+
+	boolean interactHostname(X509Certificate cert, String hostname)
+	{
+		switch (interact(hostNameMessage(cert, hostname), R.string.mtm_accept_servername)) {
+		case MTMDecision.DECISION_ALWAYS:
+			storeCert(hostname, cert);
+		case MTMDecision.DECISION_ONCE:
+			return true;
+		default:
+			return false;
+		}
+	}
+
+	protected static void interactResult(int decisionId, int choice) {
+		MTMDecision d;
+		synchronized(openDecisions) {
+			 d = openDecisions.get(decisionId);
+			 openDecisions.remove(decisionId);
+		}
+		if (d == null) {
+			LOGGER.log(Level.SEVERE, "interactResult: aborting due to stale decision reference!");
+			return;
+		}
+		synchronized(d) {
+			d.state = choice;
+			d.notify();
+		}
+	}
+	
+	class MemorizingHostnameVerifier implements HostnameVerifier {
+		private HostnameVerifier defaultVerifier;
+		
+		public MemorizingHostnameVerifier(HostnameVerifier wrapped) {
+			defaultVerifier = wrapped;
+		}
+
+		protected boolean verify(String hostname, SSLSession session, boolean interactive) {
+			LOGGER.log(Level.FINE, "hostname verifier for " + hostname + ", trying default verifier first");
+			// if the default verifier accepts the hostname, we are done
+			if (defaultVerifier.verify(hostname, session)) {
+				LOGGER.log(Level.FINE, "default verifier accepted " + hostname);
+				return true;
+			}
+			// otherwise, we check if the hostname is an alias for this cert in our keystore
+			try {
+				X509Certificate cert = (X509Certificate)session.getPeerCertificates()[0];
+				//Log.d(TAG, "cert: " + cert);
+				if (cert.equals(appKeyStore.getCertificate(hostname.toLowerCase(Locale.US)))) {
+					LOGGER.log(Level.FINE, "certificate for " + hostname + " is in our keystore. accepting.");
+					return true;
+				} else {
+					LOGGER.log(Level.FINE, "server " + hostname + " provided wrong certificate, asking user.");
+					if (interactive) {
+						return interactHostname(cert, hostname);
+					} else {
+						return false;
+					}
+				}
+			} catch (Exception e) {
+				e.printStackTrace();
+				return false;
+			}
+		}
+		
+		@Override
+		public boolean verify(String hostname, SSLSession session) {
+			return verify(hostname, session, true);
+		}
+	}
+	
+	class NonInteractiveMemorizingHostnameVerifier extends MemorizingHostnameVerifier {
+
+		public NonInteractiveMemorizingHostnameVerifier(HostnameVerifier wrapped) {
+			super(wrapped);
+		}
+		@Override
+		public boolean verify(String hostname, SSLSession session) {
+			return verify(hostname, session, true);
+		}
+		
+		
+	}
+	
+	public X509TrustManager getNonInteractive() {
+		return new NonInteractiveMemorizingTrustManager();
+	}
+	
+	private class NonInteractiveMemorizingTrustManager implements X509TrustManager {
+
+		@Override
+		public void checkClientTrusted(X509Certificate[] chain, String authType)
+				throws CertificateException {
+			MemorizingTrustManager.this.checkCertTrusted(chain, authType, false, false);
+		}
+
+		@Override
+		public void checkServerTrusted(X509Certificate[] chain, String authType)
+				throws CertificateException {
+			MemorizingTrustManager.this.checkCertTrusted(chain, authType, true, false);
+		}
+
+		@Override
+		public X509Certificate[] getAcceptedIssuers() {
+			return MemorizingTrustManager.this.getAcceptedIssuers();
+		}
+		
+	}
+}