return InvalidJid object instead of null if Jid can not be parsed

12 files changed, 249 insertions, 69 deletions

diff --git a/src/main/java/eu/siacs/conversations/entities/Bookmark.java b/src/main/java/eu/siacs/conversations/entities/Bookmark.java
index b1fa55119..1157d823a 100644
--- a/src/main/java/eu/siacs/conversations/entities/Bookmark.java
+++ b/src/main/java/eu/siacs/conversations/entities/Bookmark.java
@@ -11,6 +11,7 @@ import java.util.Locale;
 
 import eu.siacs.conversations.utils.UIHelper;
 import eu.siacs.conversations.xml.Element;
+import eu.siacs.conversations.xmpp.InvalidJid;
 import rocks.xmpp.addr.Jid;
 
 public class Bookmark extends Element implements ListItem {
@@ -35,7 +36,7 @@ public class Bookmark extends Element implements ListItem {
 		Bookmark bookmark = new Bookmark(account);
 		bookmark.setAttributes(element.getAttributes());
 		bookmark.setChildren(element.getChildren());
-		bookmark.jid =  bookmark.getAttributeAsJid("jid");
+		bookmark.jid = InvalidJid.getNullForInvalid(bookmark.getAttributeAsJid("jid"));
 		return bookmark;
 	}
 
diff --git a/src/main/java/eu/siacs/conversations/parser/AbstractParser.java b/src/main/java/eu/siacs/conversations/parser/AbstractParser.java
index abe5d8f19..05297d74d 100644
--- a/src/main/java/eu/siacs/conversations/parser/AbstractParser.java
+++ b/src/main/java/eu/siacs/conversations/parser/AbstractParser.java
@@ -11,6 +11,7 @@ import eu.siacs.conversations.entities.Conversation;
 import eu.siacs.conversations.entities.MucOptions;
 import eu.siacs.conversations.services.XmppConnectionService;
 import eu.siacs.conversations.xml.Element;
+import eu.siacs.conversations.xmpp.InvalidJid;
 import eu.siacs.conversations.xmpp.stanzas.AbstractStanza;
 import rocks.xmpp.addr.Jid;
 
@@ -37,7 +38,7 @@ public abstract class AbstractParser {
 		}
 		for(Element child : element.getChildren()) {
 			if ("delay".equals(child.getName()) && "urn:xmpp:delay".equals(child.getNamespace())) {
-				final Jid f = to == null ? null : child.getAttributeAsJid("from");
+				final Jid f = to == null ? null : InvalidJid.getNullForInvalid(child.getAttributeAsJid("from"));
 				if (f != null && (to.asBareJid().equals(f) || to.getDomain().equals(f.toString()))) {
 					continue;
 				}
@@ -115,7 +116,9 @@ public abstract class AbstractParser {
 		}
 		Jid realJid = item.getAttributeAsJid("jid");
 		MucOptions.User user = new MucOptions.User(conference.getMucOptions(), fullJid);
-		user.setRealJid(realJid);
+		if (InvalidJid.isValid(realJid)) {
+			user.setRealJid(realJid);
+		}
 		user.setAffiliation(affiliation);
 		user.setRole(role);
 		return user;
diff --git a/src/main/java/eu/siacs/conversations/parser/IqParser.java b/src/main/java/eu/siacs/conversations/parser/IqParser.java
index 9c4efc01e..d41aa170b 100644
--- a/src/main/java/eu/siacs/conversations/parser/IqParser.java
+++ b/src/main/java/eu/siacs/conversations/parser/IqParser.java
@@ -29,6 +29,7 @@ import eu.siacs.conversations.entities.Contact;
 import eu.siacs.conversations.services.XmppConnectionService;
 import eu.siacs.conversations.xml.Namespace;
 import eu.siacs.conversations.xml.Element;
+import eu.siacs.conversations.xmpp.InvalidJid;
 import eu.siacs.conversations.xmpp.OnIqPacketReceived;
 import eu.siacs.conversations.xmpp.OnUpdateBlocklist;
 import eu.siacs.conversations.xmpp.stanzas.IqPacket;
@@ -47,7 +48,7 @@ public class IqParser extends AbstractParser implements OnIqPacketReceived {
 		}
 		for (final Element item : query.getChildren()) {
 			if (item.getName().equals("item")) {
-				final Jid jid = item.getAttributeAsJid("jid");
+				final Jid jid = InvalidJid.getNullForInvalid(item.getAttributeAsJid("jid"));
 				if (jid == null) {
 					continue;
 				}
@@ -310,7 +311,7 @@ public class IqParser extends AbstractParser implements OnIqPacketReceived {
 				// Create a collection of Jids from the packet
 				for (final Element item : items) {
 					if (item.getName().equals("item")) {
-						final Jid jid = item.getAttributeAsJid("jid");
+						final Jid jid = InvalidJid.getNullForInvalid(item.getAttributeAsJid("jid"));
 						if (jid != null) {
 							jids.add(jid);
 						}
@@ -344,7 +345,7 @@ public class IqParser extends AbstractParser implements OnIqPacketReceived {
 				final Collection<Jid> jids = new ArrayList<>(items.size());
 				for (final Element item : items) {
 					if (item.getName().equals("item")) {
-						final Jid jid = item.getAttributeAsJid("jid");
+						final Jid jid = InvalidJid.getNullForInvalid(item.getAttributeAsJid("jid"));
 						if (jid != null) {
 							jids.add(jid);
 						}
diff --git a/src/main/java/eu/siacs/conversations/parser/MessageParser.java b/src/main/java/eu/siacs/conversations/parser/MessageParser.java
index c84d401e1..6da26fd11 100644
--- a/src/main/java/eu/siacs/conversations/parser/MessageParser.java
+++ b/src/main/java/eu/siacs/conversations/parser/MessageParser.java
@@ -32,6 +32,7 @@ import eu.siacs.conversations.services.XmppConnectionService;
 import eu.siacs.conversations.utils.CryptoHelper;
 import eu.siacs.conversations.xml.Namespace;
 import eu.siacs.conversations.xml.Element;
+import eu.siacs.conversations.xmpp.InvalidJid;
 import eu.siacs.conversations.xmpp.OnMessagePacketReceived;
 import eu.siacs.conversations.xmpp.chatstate.ChatState;
 import eu.siacs.conversations.xmpp.pep.Avatar;
@@ -64,7 +65,7 @@ public class MessageParser extends AbstractParser implements OnMessagePacketRece
 		for (Element child : packet.getChildren()) {
 			if (child.getName().equals("stanza-id")
 					&& Namespace.STANZA_IDS.equals(child.getNamespace())
-					&& by.equals(child.getAttributeAsJid("by"))) {
+					&& by.equals(InvalidJid.getNullForInvalid(child.getAttributeAsJid("by")))) {
 				return child.getAttribute("id");
 			}
 		}
@@ -73,7 +74,7 @@ public class MessageParser extends AbstractParser implements OnMessagePacketRece
 
 	private static Jid getTrueCounterpart(Element mucUserElement, Jid fallback) {
 		final Element item = mucUserElement == null ? null : mucUserElement.findChild("item");
-		Jid result = item == null ? null : item.getAttributeAsJid("jid");
+		Jid result = item == null ? null : InvalidJid.getNullForInvalid(item.getAttributeAsJid("jid"));
 		return result != null ? result : fallback;
 	}
 
@@ -139,17 +140,25 @@ public class MessageParser extends AbstractParser implements OnMessagePacketRece
 		if (x != null) {
 			Element invite = x.findChild("invite");
 			if (invite != null) {
-				Element pw = x.findChild("password");
-				Jid from = invite.getAttributeAsJid("from");
+				String password = x.findChildContent("password");
+				Jid from = InvalidJid.getNullForInvalid(invite.getAttributeAsJid("from"));
 				Contact contact = from == null ? null : account.getRoster().getContact(from);
-				return new Invite(message.getAttributeAsJid("from"), pw != null ? pw.getContent() : null, contact);
+				Jid room = InvalidJid.getNullForInvalid(message.getAttributeAsJid("from"));
+				if (room == null) {
+					return null;
+				}
+				return new Invite(room, password, contact);
 			}
 		} else {
 			x = message.findChild("x", "jabber:x:conference");
 			if (x != null) {
-				Jid from = message.getAttributeAsJid("from");
+				Jid from = InvalidJid.getNullForInvalid(message.getAttributeAsJid("from"));
 				Contact contact = from == null ? null : account.getRoster().getContact(from);
-				return new Invite(x.getAttributeAsJid("jid"), x.getAttribute("password"), contact);
+				Jid room = InvalidJid.getNullForInvalid(x.getAttributeAsJid("jid"));
+				if (room == null) {
+					return null;
+				}
+				return new Invite(room, x.getAttribute("password"), contact);
 			}
 		}
 		return null;
@@ -693,7 +702,7 @@ public class MessageParser extends AbstractParser implements OnMessagePacketRece
 		Element displayed = packet.findChild("displayed", "urn:xmpp:chat-markers:0");
 		if (displayed != null) {
 			final String id = displayed.getAttribute("id");
-			final Jid sender = displayed.getAttributeAsJid("sender");
+			final Jid sender = InvalidJid.getNullForInvalid(displayed.getAttributeAsJid("sender"));
 			if (packet.fromAccount(account) && !selfAddressed) {
 				dismissNotification(account, counterpart, query);
 			} else if (isTypeGroupChat) {
diff --git a/src/main/java/eu/siacs/conversations/parser/PresenceParser.java b/src/main/java/eu/siacs/conversations/parser/PresenceParser.java
index 3f828a71e..610d40e9e 100644
--- a/src/main/java/eu/siacs/conversations/parser/PresenceParser.java
+++ b/src/main/java/eu/siacs/conversations/parser/PresenceParser.java
@@ -22,6 +22,7 @@ import eu.siacs.conversations.generator.PresenceGenerator;
 import eu.siacs.conversations.services.XmppConnectionService;
 import eu.siacs.conversations.xml.Element;
 import eu.siacs.conversations.xml.Namespace;
+import eu.siacs.conversations.xmpp.InvalidJid;
 import eu.siacs.conversations.xmpp.OnPresencePacketReceived;
 import eu.siacs.conversations.xmpp.pep.Avatar;
 import eu.siacs.conversations.xmpp.stanzas.PresencePacket;
@@ -69,7 +70,7 @@ public class PresenceParser extends AbstractParser implements
 					if (item != null && !from.isBareJid()) {
 						mucOptions.setError(MucOptions.Error.NONE);
 						MucOptions.User user = parseItem(conversation, item, from);
-						if (codes.contains(MucOptions.STATUS_CODE_SELF_PRESENCE) || (codes.contains(MucOptions.STATUS_CODE_ROOM_CREATED) && jid.equals(item.getAttributeAsJid("jid")))) {
+						if (codes.contains(MucOptions.STATUS_CODE_SELF_PRESENCE) || (codes.contains(MucOptions.STATUS_CODE_ROOM_CREATED) && jid.equals(InvalidJid.getNullForInvalid(item.getAttributeAsJid("jid"))))) {
 							if (mucOptions.setOnline()) {
 								mXmppConnectionService.getAvatarService().clear(mucOptions);
 							}
diff --git a/src/main/java/eu/siacs/conversations/xml/Element.java b/src/main/java/eu/siacs/conversations/xml/Element.java
index 94ff6c564..b103e8647 100644
--- a/src/main/java/eu/siacs/conversations/xml/Element.java
+++ b/src/main/java/eu/siacs/conversations/xml/Element.java
@@ -11,6 +11,7 @@ import java.util.Locale;
 
 import eu.siacs.conversations.Config;
 import eu.siacs.conversations.utils.XmlHelper;
+import eu.siacs.conversations.xmpp.InvalidJid;
 import rocks.xmpp.addr.Jid;
 
 public class Element {
@@ -153,7 +154,7 @@ public class Element {
 			try {
 				return Jid.ofEscaped(jid);
 			} catch (final IllegalArgumentException e) {
-				return null;
+				return new InvalidJid(jid);
 			}
 		}
 		return null;
diff --git a/src/main/java/eu/siacs/conversations/xmpp/InvalidJid.java b/src/main/java/eu/siacs/conversations/xmpp/InvalidJid.java
new file mode 100644
index 000000000..e1f257fd3
--- /dev/null
+++ b/src/main/java/eu/siacs/conversations/xmpp/InvalidJid.java
@@ -0,0 +1,140 @@
+/*
+ * Copyright (c) 2018, Daniel Gultsch All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without modification,
+ * are permitted provided that the following conditions are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright notice, this
+ * list of conditions and the following disclaimer.
+ *
+ * 2. Redistributions in binary form must reproduce the above copyright notice,
+ * this list of conditions and the following disclaimer in the documentation and/or
+ * other materials provided with the distribution.
+ *
+ * 3. Neither the name of the copyright holder nor the names of its contributors
+ * may be used to endorse or promote products derived from this software without
+ * specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
+ * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
+ * DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR
+ * ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
+ * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
+ * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON
+ * ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
+ * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+package eu.siacs.conversations.xmpp;
+
+import android.support.annotation.NonNull;
+
+import rocks.xmpp.addr.Jid;
+
+public class InvalidJid implements Jid {
+
+	private final String value;
+
+	public InvalidJid(String jid) {
+		this.value = jid;
+	}
+
+	@Override
+	@NonNull
+	public String toString() {
+		return value;
+	}
+
+	@Override
+	public boolean isFullJid() {
+		throw new AssertionError("Not implemented");
+	}
+
+	@Override
+	public boolean isBareJid() {
+		throw new AssertionError("Not implemented");
+	}
+
+	@Override
+	public Jid asBareJid() {
+		throw new AssertionError("Not implemented");
+	}
+
+	@Override
+	public Jid withLocal(CharSequence charSequence) {
+		throw new AssertionError("Not implemented");
+	}
+
+	@Override
+	public Jid withResource(CharSequence charSequence) {
+		throw new AssertionError("Not implemented");
+	}
+
+	@Override
+	public Jid atSubdomain(CharSequence charSequence) {
+		throw new AssertionError("Not implemented");
+	}
+
+	@Override
+	public String getLocal() {
+		throw new AssertionError("Not implemented");
+	}
+
+	@Override
+	public String getEscapedLocal() {
+		throw new AssertionError("Not implemented");
+	}
+
+	@Override
+	public String getDomain() {
+		throw new AssertionError("Not implemented");
+	}
+
+	@Override
+	public String getResource() {
+		throw new AssertionError("Not implemented");
+	}
+
+	@Override
+	public String toEscapedString() {
+		throw new AssertionError("Not implemented");
+	}
+
+	@Override
+	public int length() {
+		return value.length();
+	}
+
+	@Override
+	public char charAt(int index) {
+		return value.charAt(index);
+	}
+
+	@Override
+	public CharSequence subSequence(int start, int end) {
+		return value.subSequence(start, end);
+	}
+
+	@Override
+	public int compareTo(@NonNull Jid o) {
+		throw new AssertionError("Not implemented");
+	}
+
+	public static Jid getNullForInvalid(Jid jid) {
+		if (jid != null && jid instanceof InvalidJid) {
+			return null;
+		} else {
+			return jid;
+		}
+	}
+
+	public static boolean isValid(Jid jid) {
+		if (jid != null && jid instanceof InvalidJid) {
+			return false;
+		} else {
+			return true;
+		}
+	}
+}
diff --git a/src/main/java/eu/siacs/conversations/xmpp/XmppConnection.java b/src/main/java/eu/siacs/conversations/xmpp/XmppConnection.java
index 3cd2e79be..72452a310 100644
--- a/src/main/java/eu/siacs/conversations/xmpp/XmppConnection.java
+++ b/src/main/java/eu/siacs/conversations/xmpp/XmppConnection.java
@@ -5,6 +5,7 @@ import android.graphics.Bitmap;
 import android.graphics.BitmapFactory;
 import android.os.SystemClock;
 import android.security.KeyChain;
+import android.support.annotation.NonNull;
 import android.util.Base64;
 import android.util.Log;
 import android.util.Pair;
@@ -179,6 +180,25 @@ public class XmppConnection implements Runnable {
 		mXmppConnectionService = service;
 	}
 
+	private static void fixResource(Context context, Account account) {
+		String resource = account.getResource();
+		int fixedPartLength = context.getString(R.string.app_name).length() + 1; //include the trailing dot
+		int randomPartLength = 4; // 3 bytes
+		if (resource != null && resource.length() > fixedPartLength + randomPartLength) {
+			if (validBase64(resource.substring(fixedPartLength, fixedPartLength + randomPartLength))) {
+				account.setResource(resource.substring(0, fixedPartLength + randomPartLength));
+			}
+		}
+	}
+
+	private static boolean validBase64(String input) {
+		try {
+			return Base64.decode(input, Base64.URL_SAFE).length == 3;
+		} catch (Throwable throwable) {
+			return false;
+		}
+	}
+
 	protected void changeStatus(final Account.State nextStatus) {
 		synchronized (this) {
 			if (Thread.currentThread().isInterrupted()) {
@@ -643,7 +663,7 @@ public class XmppConnection implements Runnable {
 
 	private void acknowledgeStanzaUpTo(int serverCount) {
 		if (serverCount > stanzasSent) {
-			Log.e(Config.LOGTAG,"server acknowledged more stanzas than we sent. serverCount="+serverCount+", ourCount="+stanzasSent);
+			Log.e(Config.LOGTAG, "server acknowledged more stanzas than we sent. serverCount=" + serverCount + ", ourCount=" + stanzasSent);
 		}
 		for (int i = 0; i < mStanzaQueue.size(); ++i) {
 			if (serverCount >= mStanzaQueue.keyAt(i)) {
@@ -661,8 +681,8 @@ public class XmppConnection implements Runnable {
 		}
 	}
 
-	private Element processPacket(final Tag currentTag, final int packetType)
-			throws XmlPullParserException, IOException {
+	private @NonNull
+	Element processPacket(final Tag currentTag, final int packetType) throws XmlPullParserException, IOException {
 		Element element;
 		switch (packetType) {
 			case PACKET_IQ:
@@ -675,7 +695,7 @@ public class XmppConnection implements Runnable {
 				element = new PresencePacket();
 				break;
 			default:
-				return null;
+				throw new AssertionError("Should never encounter invalid type");
 		}
 		element.setAttributes(currentTag.getAttributes());
 		Tag nextTag = tagReader.readTag();
@@ -707,7 +727,7 @@ public class XmppConnection implements Runnable {
 		if (inSmacksSession) {
 			++stanzasReceived;
 		} else if (features.sm()) {
-			Log.d(Config.LOGTAG,account.getJid().asBareJid()+": not counting stanza("+element.getClass().getSimpleName()+"). Not in smacks session.");
+			Log.d(Config.LOGTAG, account.getJid().asBareJid() + ": not counting stanza(" + element.getClass().getSimpleName() + "). Not in smacks session.");
 		}
 		lastPacketReceived = SystemClock.elapsedRealtime();
 		if (Config.BACKGROUND_STANZA_LOGGING && mXmppConnectionService.checkListeners()) {
@@ -718,11 +738,10 @@ public class XmppConnection implements Runnable {
 
 	private void processIq(final Tag currentTag) throws XmlPullParserException, IOException {
 		final IqPacket packet = (IqPacket) processPacket(currentTag, PACKET_IQ);
-
-		if (packet.getId() == null) {
-			return; // an iq packet without id is definitely invalid
+		if (!packet.valid()) {
+			Log.e(Config.LOGTAG, "encountered invalid iq from='" + packet.getFrom() + "' to='" + packet.getTo() + "'");
+			return;
 		}
-
 		if (packet instanceof JinglePacket) {
 			if (this.jingleListener != null) {
 				this.jingleListener.onJinglePacketReceived(account, (JinglePacket) packet);
@@ -764,11 +783,19 @@ public class XmppConnection implements Runnable {
 
 	private void processMessage(final Tag currentTag) throws XmlPullParserException, IOException {
 		final MessagePacket packet = (MessagePacket) processPacket(currentTag, PACKET_MESSAGE);
+		if (!packet.valid()) {
+			Log.e(Config.LOGTAG, "encountered invalid message from='" + packet.getFrom() + "' to='" + packet.getTo() + "'");
+			return;
+		}
 		this.messageListener.onMessagePacketReceived(account, packet);
 	}
 
 	private void processPresence(final Tag currentTag) throws XmlPullParserException, IOException {
 		PresencePacket packet = (PresencePacket) processPacket(currentTag, PACKET_PRESENCE);
+		if (!packet.valid()) {
+			Log.e(Config.LOGTAG, "encountered invalid presence from='" + packet.getFrom() + "' to='" + packet.getTo() + "'");
+			return;
+		}
 		this.presenceListener.onPresencePacketReceived(account, packet);
 	}
 
@@ -951,7 +978,7 @@ public class XmppConnection implements Runnable {
 					}
 				}
 				throw new StateChangingError(Account.State.REGISTRATION_FAILED);
-			} else if (query.hasChild("instructions") || query.hasChild("x",Namespace.OOB)) {
+			} else if (query.hasChild("instructions") || query.hasChild("x", Namespace.OOB)) {
 				final String instructions = query.findChildContent("instructions");
 				final Element oob = query.findChild("x", Namespace.OOB);
 				final String url = oob == null ? null : oob.findChildContent("url");
@@ -965,7 +992,7 @@ public class XmppConnection implements Runnable {
 				}
 				throw new StateChangingError(Account.State.REGISTRATION_FAILED);
 			}
-		},true);
+		}, true);
 	}
 
 	private void setAccountCreationFailed(String url) {
@@ -1002,7 +1029,7 @@ public class XmppConnection implements Runnable {
 		try {
 			mXmppConnectionService.restoredFromDatabaseLatch.await();
 		} catch (InterruptedException e) {
-			Log.d(Config.LOGTAG,account.getJid().asBareJid()+": interrupted while waiting for DB restore during bind");
+			Log.d(Config.LOGTAG, account.getJid().asBareJid() + ": interrupted while waiting for DB restore during bind");
 			return;
 		}
 		clearIqCallbacks();
@@ -1026,7 +1053,7 @@ public class XmppConnection implements Runnable {
 					try {
 						Jid assignedJid = Jid.ofEscaped(jid.getContent());
 						if (!account.getJid().getDomain().equals(assignedJid.getDomain())) {
-							Log.d(Config.LOGTAG,account.getJid().asBareJid()+": server tried to re-assign domain to "+assignedJid.getDomain());
+							Log.d(Config.LOGTAG, account.getJid().asBareJid() + ": server tried to re-assign domain to " + assignedJid.getDomain());
 							throw new StateChangingError(Account.State.BIND_FAILURE);
 						}
 						if (account.setJid(assignedJid)) {
@@ -1054,7 +1081,7 @@ public class XmppConnection implements Runnable {
 				account.setResource(createNewResource());
 			}
 			throw new StateChangingError(Account.State.BIND_FAILURE);
-		},true);
+		}, true);
 	}
 
 	private void clearIqCallbacks() {
@@ -1100,7 +1127,7 @@ public class XmppConnection implements Runnable {
 			} else if (packet.getType() != IqPacket.TYPE.TIMEOUT) {
 				throw new StateChangingError(Account.State.SESSION_FAILURE);
 			}
-		},true);
+		}, true);
 	}
 
 	private void sendPostBindInitialization() {
@@ -1225,7 +1252,7 @@ public class XmppConnection implements Runnable {
 				final List<Element> elements = packet.query().getChildren();
 				for (final Element element : elements) {
 					if (element.getName().equals("item")) {
-						final Jid jid = element.getAttributeAsJid("jid");
+						final Jid jid = InvalidJid.getNullForInvalid(element.getAttributeAsJid("jid"));
 						if (jid != null && !jid.equals(Jid.of(account.getServer()))) {
 							items.add(jid);
 						}
@@ -1295,26 +1322,7 @@ public class XmppConnection implements Runnable {
 	}
 
 	private String createNewResource() {
-		return mXmppConnectionService.getString(R.string.app_name)+'.'+nextRandomId(true);
-	}
-
-	private static void fixResource(Context context, Account account) {
-		String resource = account.getResource();
-		int fixedPartLength = context.getString(R.string.app_name).length() + 1; //include the trailing dot
-		int randomPartLength = 4; // 3 bytes
-		if (resource != null && resource.length() > fixedPartLength + randomPartLength) {
-			if (validBase64(resource.substring(fixedPartLength,fixedPartLength + randomPartLength))) {
-				account.setResource(resource.substring(0,fixedPartLength + randomPartLength));
-			}
-		}
-	}
-
-	private static boolean validBase64(String input) {
-		try {
-			return Base64.decode(input, Base64.URL_SAFE).length == 3;
-		} catch (Throwable throwable) {
-			return false;
-		}
+		return mXmppConnectionService.getString(R.string.app_name) + '.' + nextRandomId(true);
 	}
 
 	private String nextRandomId() {
@@ -1339,7 +1347,7 @@ public class XmppConnection implements Runnable {
 				packetCallbacks.put(packet.getId(), new Pair<>(packet, callback));
 			}
 		}
-		this.sendPacket(packet,force);
+		this.sendPacket(packet, force);
 		return packet.getId();
 	}
 
@@ -1352,7 +1360,7 @@ public class XmppConnection implements Runnable {
 	}
 
 	private synchronized void sendPacket(final AbstractStanza packet) {
-		sendPacket(packet,false);
+		sendPacket(packet, false);
 	}
 
 	private synchronized void sendPacket(final AbstractStanza packet, final boolean force) {
@@ -1365,7 +1373,7 @@ public class XmppConnection implements Runnable {
 			if (force || isBound) {
 				tagWriter.writeStanzaAsync(packet);
 			} else {
-				Log.d(Config.LOGTAG,account.getJid().asBareJid()+" do not write stanza to unbound stream "+packet.toString());
+				Log.d(Config.LOGTAG, account.getJid().asBareJid() + " do not write stanza to unbound stream " + packet.toString());
 			}
 			if (packet instanceof AbstractAcknowledgeableStanza) {
 				AbstractAcknowledgeableStanza stanza = (AbstractAcknowledgeableStanza) packet;
@@ -1465,18 +1473,18 @@ public class XmppConnection implements Runnable {
 				final Socket currentSocket = this.socket;
 				final CountDownLatch streamCountDownLatch = this.mStreamCountDownLatch;
 				try {
-					currentTagWriter.await(1,TimeUnit.SECONDS);
+					currentTagWriter.await(1, TimeUnit.SECONDS);
 					Log.d(Config.LOGTAG, account.getJid().asBareJid() + ": closing stream");
 					currentTagWriter.writeTag(Tag.end("stream:stream"));
 					if (streamCountDownLatch != null) {
-							if (streamCountDownLatch.await(1, TimeUnit.SECONDS)) {
+						if (streamCountDownLatch.await(1, TimeUnit.SECONDS)) {
 							Log.d(Config.LOGTAG, account.getJid().asBareJid() + ": remote ended stream");
 						} else {
 							Log.d(Config.LOGTAG, account.getJid().asBareJid() + ": remote has not closed socket. force closing");
 						}
 					}
 				} catch (InterruptedException e) {
-					Log.d(Config.LOGTAG,account.getJid().asBareJid()+": interrupted while gracefully closing stream");
+					Log.d(Config.LOGTAG, account.getJid().asBareJid() + ": interrupted while gracefully closing stream");
 				} catch (final IOException e) {
 					Log.d(Config.LOGTAG, account.getJid().asBareJid() + ": io exception during disconnect (" + e.getMessage() + ")");
 				} finally {
@@ -1769,7 +1777,7 @@ public class XmppConnection implements Runnable {
 		}
 
 		public boolean pepPublishOptions() {
-			return hasDiscoFeature(account.getJid().asBareJid(),Namespace.PUBSUB_PUBLISH_OPTIONS);
+			return hasDiscoFeature(account.getJid().asBareJid(), Namespace.PUBSUB_PUBLISH_OPTIONS);
 		}
 
 		public boolean pepOmemoWhitelisted() {
diff --git a/src/main/java/eu/siacs/conversations/xmpp/jingle/JingleCandidate.java b/src/main/java/eu/siacs/conversations/xmpp/jingle/JingleCandidate.java
index bb7b60a3d..64db37f66 100644
--- a/src/main/java/eu/siacs/conversations/xmpp/jingle/JingleCandidate.java
+++ b/src/main/java/eu/siacs/conversations/xmpp/jingle/JingleCandidate.java
@@ -4,6 +4,7 @@ import java.util.ArrayList;
 import java.util.List;
 
 import eu.siacs.conversations.xml.Element;
+import eu.siacs.conversations.xmpp.InvalidJid;
 import rocks.xmpp.addr.Jid;
 
 public class JingleCandidate {
@@ -108,7 +109,7 @@ public class JingleCandidate {
 		JingleCandidate parsedCandidate = new JingleCandidate(
 				candidate.getAttribute("cid"), false);
 		parsedCandidate.setHost(candidate.getAttribute("host"));
-		parsedCandidate.setJid(candidate.getAttributeAsJid("jid"));
+		parsedCandidate.setJid(InvalidJid.getNullForInvalid(candidate.getAttributeAsJid("jid")));
 		parsedCandidate.setType(candidate.getAttribute("type"));
 		parsedCandidate.setPriority(Integer.parseInt(candidate
 				.getAttribute("priority")));
diff --git a/src/main/java/eu/siacs/conversations/xmpp/stanzas/AbstractAcknowledgeableStanza.java b/src/main/java/eu/siacs/conversations/xmpp/stanzas/AbstractAcknowledgeableStanza.java
index fa5e6fbdd..095075616 100644
--- a/src/main/java/eu/siacs/conversations/xmpp/stanzas/AbstractAcknowledgeableStanza.java
+++ b/src/main/java/eu/siacs/conversations/xmpp/stanzas/AbstractAcknowledgeableStanza.java
@@ -1,6 +1,8 @@
 package eu.siacs.conversations.xmpp.stanzas;
 
 import eu.siacs.conversations.xml.Element;
+import eu.siacs.conversations.xmpp.InvalidJid;
+import rocks.xmpp.addr.Jid;
 
 abstract public class AbstractAcknowledgeableStanza extends AbstractStanza {
 
@@ -28,4 +30,8 @@ abstract public class AbstractAcknowledgeableStanza extends AbstractStanza {
 		}
 		return null;
 	}
+
+	public boolean valid() {
+		return InvalidJid.isValid(getFrom()) && InvalidJid.isValid(getTo());
+	}
 }
diff --git a/src/main/java/eu/siacs/conversations/xmpp/stanzas/AbstractStanza.java b/src/main/java/eu/siacs/conversations/xmpp/stanzas/AbstractStanza.java
index d17eb3254..7be738f3a 100644
--- a/src/main/java/eu/siacs/conversations/xmpp/stanzas/AbstractStanza.java
+++ b/src/main/java/eu/siacs/conversations/xmpp/stanzas/AbstractStanza.java
@@ -31,20 +31,23 @@ public class AbstractStanza extends Element {
 	}
 
 	public boolean fromServer(final Account account) {
-		return getFrom() == null
-			|| getFrom().equals(Jid.of(account.getServer()))
-			|| getFrom().equals(account.getJid().asBareJid())
-			|| getFrom().equals(account.getJid());
+		final Jid from = getFrom();
+		return from == null
+			|| from.equals(Jid.of(account.getServer()))
+			|| from.equals(account.getJid().asBareJid())
+			|| from.equals(account.getJid());
 	}
 
 	public boolean toServer(final Account account) {
-		return getTo() == null
-			|| getTo().equals(Jid.of(account.getServer()))
-			|| getTo().equals(account.getJid().asBareJid())
-			|| getTo().equals(account.getJid());
+		final Jid to = getTo();
+		return to == null
+			|| to.equals(Jid.of(account.getServer()))
+			|| to.equals(account.getJid().asBareJid())
+			|| to.equals(account.getJid());
 	}
 
 	public boolean fromAccount(final Account account) {
-		return getFrom() != null && getFrom().asBareJid().equals(account.getJid().asBareJid());
+		final Jid from = getFrom();
+		return from != null && from.asBareJid().equals(account.getJid().asBareJid());
 	}
 }
diff --git a/src/main/java/eu/siacs/conversations/xmpp/stanzas/IqPacket.java b/src/main/java/eu/siacs/conversations/xmpp/stanzas/IqPacket.java
index 302dc78e8..ba8588e1f 100644
--- a/src/main/java/eu/siacs/conversations/xmpp/stanzas/IqPacket.java
+++ b/src/main/java/eu/siacs/conversations/xmpp/stanzas/IqPacket.java
@@ -66,4 +66,10 @@ public class IqPacket extends AbstractAcknowledgeableStanza {
 		return packet;
 	}
 
+	@Override
+	public boolean valid() {
+		String id = getId();
+		return id != null && super.valid();
+	}
+
 }