Ask for key trust when sending messages

If the contact (or the own account) has keys that have UNDECIDED trust,
we now drop the user into the new TrustKeysActivity, where they have to
decide for each new key whether it should be TRUSTED or UNTRUSTED.

11 files changed, 580 insertions, 57 deletions

diff --git a/src/main/AndroidManifest.xml b/src/main/AndroidManifest.xml
index 9fe37017..b0611f84 100644
--- a/src/main/AndroidManifest.xml
+++ b/src/main/AndroidManifest.xml
@@ -131,6 +131,10 @@
             </intent-filter>
         </activity>
         <activity
+            android:name=".ui.TrustKeysActivity"
+            android:label="@string/trust_keys"
+            android:windowSoftInputMode="stateAlwaysHidden"/>
+        <activity
             android:name="de.duenndns.ssl.MemorizingActivity"
             android:theme="@style/ConversationsTheme"
             tools:replace="android:theme"/>
diff --git a/src/main/java/eu/siacs/conversations/crypto/axolotl/AxolotlService.java b/src/main/java/eu/siacs/conversations/crypto/axolotl/AxolotlService.java
index 8358125d..b05112a3 100644
--- a/src/main/java/eu/siacs/conversations/crypto/axolotl/AxolotlService.java
+++ b/src/main/java/eu/siacs/conversations/crypto/axolotl/AxolotlService.java
@@ -115,6 +115,10 @@ public class AxolotlService {
 						return "Untrusted";
 				}
 			}
+
+			public static Trust fromBoolean(Boolean trusted) {
+				return trusted?TRUSTED:UNTRUSTED;
+			}
 		};
 
 		private static IdentityKeyPair generateIdentityKeyPair() {
@@ -275,6 +279,10 @@ public class AxolotlService {
 			mXmppConnectionService.databaseBackend.setIdentityKeyTrust(account, fingerprint, trust);
 		}
 
+		public Set<IdentityKey> getContactUndecidedKeys(String bareJid) {
+			return mXmppConnectionService.databaseBackend.loadIdentityKeys(account, bareJid, Trust.UNDECIDED);
+		}
+
 		// --------------------------------------
 		// SessionStore
 		// --------------------------------------
@@ -658,6 +666,14 @@ public class AxolotlService {
 		return axolotlStore.getIdentityKeyPair().getPublicKey();
 	}
 
+	public Set<IdentityKey> getPendingKeys() {
+		return axolotlStore.getContactUndecidedKeys(account.getJid().toBareJid().toString());
+	}
+
+	public Set<IdentityKey> getPendingKeys(Contact contact) {
+		return axolotlStore.getContactUndecidedKeys(contact.getJid().toBareJid().toString());
+	}
+
 	private AxolotlAddress getAddressForJid(Jid jid) {
 		return new AxolotlAddress(jid.toString(), 0);
 	}
@@ -852,14 +868,32 @@ public class AxolotlService {
 		axolotlStore.setFingerprintTrust(fingerprint, trust);
 	}
 
-	private void buildSessionFromPEP(final Conversation conversation, final AxolotlAddress address) {
-		Log.i(Config.LOGTAG, AxolotlService.getLogprefix(account)+"Building new sesstion for " + address.getDeviceId());
+	private void buildSessionFromPEP(final Conversation conversation, final AxolotlAddress address, final boolean flushWaitingQueueAfterFetch) {
+		Log.i(Config.LOGTAG, AxolotlService.getLogprefix(account) + "Building new sesstion for " + address.getDeviceId());
 
 		try {
 			IqPacket bundlesPacket = mXmppConnectionService.getIqGenerator().retrieveBundlesForDevice(
 					Jid.fromString(address.getName()), address.getDeviceId());
 			Log.d(Config.LOGTAG, AxolotlService.getLogprefix(account)+"Retrieving bundle: " + bundlesPacket);
 			mXmppConnectionService.sendIqPacket(account, bundlesPacket, new OnIqPacketReceived() {
+				private void finish() {
+					AxolotlAddress ownAddress = new AxolotlAddress(conversation.getAccount().getJid().toBareJid().toString(),0);
+					AxolotlAddress foreignAddress = new AxolotlAddress(conversation.getJid().toBareJid().toString(),0);
+					if (!fetchStatusMap.getAll(ownAddress).containsValue(FetchStatus.PENDING)
+							&& !fetchStatusMap.getAll(foreignAddress).containsValue(FetchStatus.PENDING)) {
+						if (flushWaitingQueueAfterFetch) {
+							conversation.findUnsentMessagesWithEncryption(Message.ENCRYPTION_AXOLOTL,
+									new Conversation.OnMessageFound() {
+										@Override
+										public void onMessageFound(Message message) {
+											processSending(message);
+										}
+									});
+						}
+						mXmppConnectionService.newKeysAvailable();
+					}
+				}
+
 				@Override
 				public void onIqPacketReceived(Account account, IqPacket packet) {
 					Log.d(Config.LOGTAG, AxolotlService.getLogprefix(account)+"Received preKey IQ packet, processing...");
@@ -869,6 +903,7 @@ public class AxolotlService {
 					if (preKeyBundleList.isEmpty() || bundle == null) {
 						Log.e(Config.LOGTAG, AxolotlService.getLogprefix(account)+"preKey IQ packet invalid: " + packet);
 						fetchStatusMap.put(address, FetchStatus.ERROR);
+						finish();
 						return;
 					}
 					Random random = new Random();
@@ -876,6 +911,7 @@ public class AxolotlService {
 					if (preKey == null) {
 						//should never happen
 						fetchStatusMap.put(address, FetchStatus.ERROR);
+						finish();
 						return;
 					}
 
@@ -898,18 +934,7 @@ public class AxolotlService {
 						fetchStatusMap.put(address, FetchStatus.ERROR);
 					}
 
-					AxolotlAddress ownAddress = new AxolotlAddress(conversation.getAccount().getJid().toBareJid().toString(),0);
-					AxolotlAddress foreignAddress = new AxolotlAddress(conversation.getJid().toBareJid().toString(),0);
-					if (!fetchStatusMap.getAll(ownAddress).containsValue(FetchStatus.PENDING)
-							&& !fetchStatusMap.getAll(foreignAddress).containsValue(FetchStatus.PENDING)) {
-						conversation.findUnsentMessagesWithEncryption(Message.ENCRYPTION_AXOLOTL,
-								new Conversation.OnMessageFound() {
-									@Override
-									public void onMessageFound(Message message) {
-										processSending(message);
-									}
-								});
-					}
+					finish();
 				}
 			});
 		} catch (InvalidJidException e) {
@@ -917,48 +942,75 @@ public class AxolotlService {
 		}
 	}
 
-	private boolean createSessionsIfNeeded(Conversation conversation) {
-		boolean newSessions = false;
-		Log.i(Config.LOGTAG, AxolotlService.getLogprefix(account)+"Creating axolotl sessions if needed...");
+	public Set<AxolotlAddress> findDevicesWithoutSession(final Conversation conversation) {
+		Log.d(Config.LOGTAG, AxolotlService.getLogprefix(account) + "Finding devices without session for " + conversation.getContact().getJid().toBareJid());
 		Jid contactJid = conversation.getContact().getJid().toBareJid();
 		Set<AxolotlAddress> addresses = new HashSet<>();
 		if(deviceIds.get(contactJid) != null) {
 			for(Integer foreignId:this.deviceIds.get(contactJid)) {
-				Log.d(Config.LOGTAG, AxolotlService.getLogprefix(account)+"Found device "+account.getJid().toBareJid()+":"+foreignId);
-				addresses.add(new AxolotlAddress(contactJid.toString(), foreignId));
+				AxolotlAddress address = new AxolotlAddress(contactJid.toString(), foreignId);
+				if(sessions.get(address) == null) {
+					IdentityKey identityKey = axolotlStore.loadSession(address).getSessionState().getRemoteIdentityKey();
+					if ( identityKey != null ) {
+						Log.d(Config.LOGTAG, AxolotlService.getLogprefix(account)+"Already have session for " +  address.toString() + ", adding to cache...");
+						XmppAxolotlSession session = new XmppAxolotlSession(account, axolotlStore, address, identityKey.getFingerprint().replaceAll("\\s", ""));
+						sessions.put(address, session);
+					} else {
+						Log.d(Config.LOGTAG, AxolotlService.getLogprefix(account) + "Found device " + account.getJid().toBareJid() + ":" + foreignId);
+						addresses.add(new AxolotlAddress(contactJid.toString(), foreignId));
+					}
+				}
 			}
 		} else {
 			Log.w(Config.LOGTAG, AxolotlService.getLogprefix(account) + "Have no target devices in PEP!");
 		}
-		Log.d(Config.LOGTAG, AxolotlService.getLogprefix(account)+"Checking own account "+account.getJid().toBareJid());
 		if(deviceIds.get(account.getJid().toBareJid()) != null) {
 			for(Integer ownId:this.deviceIds.get(account.getJid().toBareJid())) {
-				Log.d(Config.LOGTAG, AxolotlService.getLogprefix(account)+"Found device "+account.getJid().toBareJid()+":"+ownId);
-				addresses.add(new AxolotlAddress(account.getJid().toBareJid().toString(), ownId));
+				AxolotlAddress address = new AxolotlAddress(account.getJid().toBareJid().toString(), ownId);
+				if(sessions.get(address) == null) {
+					IdentityKey identityKey = axolotlStore.loadSession(address).getSessionState().getRemoteIdentityKey();
+					if ( identityKey != null ) {
+						Log.d(Config.LOGTAG, AxolotlService.getLogprefix(account)+"Already have session for " +  address.toString() + ", adding to cache...");
+						XmppAxolotlSession session = new XmppAxolotlSession(account, axolotlStore, address, identityKey.getFingerprint().replaceAll("\\s", ""));
+						sessions.put(address, session);
+					} else {
+						Log.d(Config.LOGTAG, AxolotlService.getLogprefix(account) + "Found device " + account.getJid().toBareJid() + ":" + ownId);
+						addresses.add(new AxolotlAddress(account.getJid().toBareJid().toString(), ownId));
+					}
+				}
 			}
 		}
+
+		return addresses;
+	}
+
+	public boolean createSessionsIfNeeded(final Conversation conversation, final boolean flushWaitingQueueAfterFetch) {
+		Log.i(Config.LOGTAG, AxolotlService.getLogprefix(account) + "Creating axolotl sessions if needed...");
+		boolean newSessions = false;
+		Set<AxolotlAddress> addresses = findDevicesWithoutSession(conversation);
 		for (AxolotlAddress address : addresses) {
-			Log.d(Config.LOGTAG, AxolotlService.getLogprefix(account)+"Processing device: " + address.toString());
+			Log.d(Config.LOGTAG, AxolotlService.getLogprefix(account) + "Processing device: " + address.toString());
 			FetchStatus status = fetchStatusMap.get(address);
-			XmppAxolotlSession session = sessions.get(address);
-			if ( session == null && ( status == null || status == FetchStatus.ERROR) ) {
-				IdentityKey identityKey = axolotlStore.loadSession(address).getSessionState().getRemoteIdentityKey();
-				if ( identityKey != null ) {
-					Log.d(Config.LOGTAG, AxolotlService.getLogprefix(account)+"Already have session for " +  address.toString() + ", adding to cache...");
-					session = new XmppAxolotlSession(account, axolotlStore, address, identityKey.getFingerprint().replaceAll("\\s", ""));
-					sessions.put(address, session);
-				} else {
+			if ( status == null || status == FetchStatus.ERROR ) {
 					fetchStatusMap.put(address, FetchStatus.PENDING);
-					this.buildSessionFromPEP(conversation, address);
+					this.buildSessionFromPEP(conversation, address, flushWaitingQueueAfterFetch);
 					newSessions = true;
-				}
 			} else {
-				Log.d(Config.LOGTAG, AxolotlService.getLogprefix(account)+"Already have session for " +  address.toString());
+				Log.d(Config.LOGTAG, AxolotlService.getLogprefix(account)+"Already fetching bundle for " +  address.toString());
 			}
 		}
+
 		return newSessions;
 	}
 
+	public boolean hasPendingKeyFetches(Conversation conversation) {
+		AxolotlAddress ownAddress = new AxolotlAddress(account.getJid().toBareJid().toString(),0);
+		AxolotlAddress foreignAddress = new AxolotlAddress(conversation.getJid().toBareJid().toString(),0);
+		return fetchStatusMap.getAll(ownAddress).containsValue(FetchStatus.PENDING)
+				||fetchStatusMap.getAll(foreignAddress).containsValue(FetchStatus.PENDING);
+
+	}
+
 	@Nullable
 	public XmppAxolotlMessage encrypt(Message message ){
 		final String content;
@@ -1013,10 +1065,9 @@ public class AxolotlService {
 		});
 	}
 
-	public void prepareMessage(Message message) {
+	public void prepareMessage(final Message message) {
 		if (!messageCache.containsKey(message.getUuid())) {
-			boolean newSessions = createSessionsIfNeeded(message.getConversation());
-
+			boolean newSessions = createSessionsIfNeeded(message.getConversation(), true);
 			if (!newSessions) {
 				this.processSending(message);
 			}
diff --git a/src/main/java/eu/siacs/conversations/persistance/DatabaseBackend.java b/src/main/java/eu/siacs/conversations/persistance/DatabaseBackend.java
index 39ef5d36..a2c62a8c 100644
--- a/src/main/java/eu/siacs/conversations/persistance/DatabaseBackend.java
+++ b/src/main/java/eu/siacs/conversations/persistance/DatabaseBackend.java
@@ -834,10 +834,19 @@ public class DatabaseBackend extends SQLiteOpenHelper {
 	}
 
 	public Set<IdentityKey> loadIdentityKeys(Account account, String name) {
+		return loadIdentityKeys(account, name, null);
+	}
+
+	public Set<IdentityKey> loadIdentityKeys(Account account, String name, AxolotlService.SQLiteAxolotlStore.Trust trust) {
 		Set<IdentityKey> identityKeys = new HashSet<>();
 		Cursor cursor = getIdentityKeyCursor(account, name, false);
 
 		while(cursor.moveToNext()) {
+			if ( trust != null &&
+					cursor.getInt(cursor.getColumnIndex(AxolotlService.SQLiteAxolotlStore.TRUSTED))
+							!= trust.ordinal()) {
+				continue;
+			}
 			try {
 				identityKeys.add(new IdentityKey(Base64.decode(cursor.getString(cursor.getColumnIndex(AxolotlService.SQLiteAxolotlStore.KEY)),Base64.DEFAULT),0));
 			} catch (InvalidKeyException e) {
diff --git a/src/main/java/eu/siacs/conversations/services/XmppConnectionService.java b/src/main/java/eu/siacs/conversations/services/XmppConnectionService.java
index 08c0b3fa..cc113cef 100644
--- a/src/main/java/eu/siacs/conversations/services/XmppConnectionService.java
+++ b/src/main/java/eu/siacs/conversations/services/XmppConnectionService.java
@@ -85,6 +85,7 @@ import eu.siacs.conversations.xmpp.OnContactStatusChanged;
 import eu.siacs.conversations.xmpp.OnIqPacketReceived;
 import eu.siacs.conversations.xmpp.OnMessageAcknowledged;
 import eu.siacs.conversations.xmpp.OnMessagePacketReceived;
+import eu.siacs.conversations.xmpp.OnNewKeysAvailable;
 import eu.siacs.conversations.xmpp.OnPresencePacketReceived;
 import eu.siacs.conversations.xmpp.OnStatusChanged;
 import eu.siacs.conversations.xmpp.OnUpdateBlocklist;
@@ -307,6 +308,8 @@ public class XmppConnectionService extends Service implements OnPhoneContactsLoa
 	private int rosterChangedListenerCount = 0;
 	private OnMucRosterUpdate mOnMucRosterUpdate = null;
 	private int mucRosterChangedListenerCount = 0;
+	private OnNewKeysAvailable mOnNewKeysAvailable = null;
+	private int newKeysAvailableListenerCount = 0;
 	private SecureRandom mRandom;
 	private OpenPgpServiceConnection pgpServiceConnection;
 	private PgpEngine mPgpEngine = null;
@@ -1344,17 +1347,17 @@ public class XmppConnectionService extends Service implements OnPhoneContactsLoa
 				switchToForeground();
 			}
 			this.mOnUpdateBlocklist = listener;
-			if (this.updateBlocklistListenerCount < 2) {
-				this.updateBlocklistListenerCount++;
+			if (this.newKeysAvailableListenerCount < 2) {
+				this.newKeysAvailableListenerCount++;
 			}
 		}
 	}
 
 	public void removeOnUpdateBlocklistListener() {
 		synchronized (this) {
-			this.updateBlocklistListenerCount--;
-			if (this.updateBlocklistListenerCount <= 0) {
-				this.updateBlocklistListenerCount = 0;
+			this.newKeysAvailableListenerCount--;
+			if (this.newKeysAvailableListenerCount <= 0) {
+				this.newKeysAvailableListenerCount = 0;
 				this.mOnUpdateBlocklist = null;
 				if (checkListeners()) {
 					switchToBackground();
@@ -1363,6 +1366,30 @@ public class XmppConnectionService extends Service implements OnPhoneContactsLoa
 		}
 	}
 
+	public void setOnNewKeysAvailableListener(final OnNewKeysAvailable listener) {
+		synchronized (this) {
+			if (checkListeners()) {
+				switchToForeground();
+			}
+			this.mOnNewKeysAvailable = listener;
+			if (this.newKeysAvailableListenerCount < 2) {
+				this.newKeysAvailableListenerCount++;
+			}
+		}
+	}
+
+	public void removeOnNewKeysAvailableListener() {
+		synchronized (this) {
+			this.newKeysAvailableListenerCount--;
+			if (this.newKeysAvailableListenerCount <= 0) {
+				this.newKeysAvailableListenerCount = 0;
+				this.mOnNewKeysAvailable = null;
+				if (checkListeners()) {
+					switchToBackground();
+				}
+			}
+		}
+	}
 	public void setOnMucRosterUpdateListener(OnMucRosterUpdate listener) {
 		synchronized (this) {
 			if (checkListeners()) {
@@ -1393,7 +1420,8 @@ public class XmppConnectionService extends Service implements OnPhoneContactsLoa
 				&& this.mOnConversationUpdate == null
 				&& this.mOnRosterUpdate == null
 				&& this.mOnUpdateBlocklist == null
-				&& this.mOnShowErrorToast == null);
+				&& this.mOnShowErrorToast == null
+				&& this.mOnNewKeysAvailable == null);
 	}
 
 	private void switchToForeground() {
@@ -2281,6 +2309,12 @@ public class XmppConnectionService extends Service implements OnPhoneContactsLoa
 		}
 	}
 
+	public void newKeysAvailable() {
+		if(mOnNewKeysAvailable != null) {
+			mOnNewKeysAvailable.onNewKeysAvailable();
+		}
+	}
+
 	public Account findAccountByJid(final Jid accountJid) {
 		for (Account account : this.accounts) {
 			if (account.getJid().toBareJid().equals(accountJid.toBareJid())) {
diff --git a/src/main/java/eu/siacs/conversations/ui/ConversationActivity.java b/src/main/java/eu/siacs/conversations/ui/ConversationActivity.java
index 2e50af3b..a6cd0431 100644
--- a/src/main/java/eu/siacs/conversations/ui/ConversationActivity.java
+++ b/src/main/java/eu/siacs/conversations/ui/ConversationActivity.java
@@ -65,11 +65,14 @@ public class ConversationActivity extends XmppActivity
 	public static final int REQUEST_SEND_MESSAGE = 0x0201;
 	public static final int REQUEST_DECRYPT_PGP = 0x0202;
 	public static final int REQUEST_ENCRYPT_MESSAGE = 0x0207;
+	public static final int REQUEST_TRUST_KEYS_TEXT = 0x0208;
+	public static final int REQUEST_TRUST_KEYS_MENU = 0x0209;
 	public static final int ATTACHMENT_CHOICE_CHOOSE_IMAGE = 0x0301;
 	public static final int ATTACHMENT_CHOICE_TAKE_PHOTO = 0x0302;
 	public static final int ATTACHMENT_CHOICE_CHOOSE_FILE = 0x0303;
 	public static final int ATTACHMENT_CHOICE_RECORD_VOICE = 0x0304;
 	public static final int ATTACHMENT_CHOICE_LOCATION = 0x0305;
+	public static final int ATTACHMENT_CHOICE_INVALID = 0x0306;
 	private static final String STATE_OPEN_CONVERSATION = "state_open_conversation";
 	private static final String STATE_PANEL_OPEN = "state_panel_open";
 	private static final String STATE_PENDING_URI = "state_pending_uri";
@@ -79,6 +82,7 @@ public class ConversationActivity extends XmppActivity
 	final private List<Uri> mPendingImageUris = new ArrayList<>();
 	final private List<Uri> mPendingFileUris = new ArrayList<>();
 	private Uri mPendingGeoUri = null;
+	private boolean forbidProcessingPendings = false;
 
 	private View mContentView;
 
@@ -401,7 +405,7 @@ public class ConversationActivity extends XmppActivity
 		return true;
 	}
 
-	private void selectPresenceToAttachFile(final int attachmentChoice, final int encryption) {
+	protected void selectPresenceToAttachFile(final int attachmentChoice, final int encryption) {
 		final Conversation conversation = getSelectedConversation();
 		final Account account = conversation.getAccount();
 		final OnPresenceSelected callback = new OnPresenceSelected() {
@@ -537,7 +541,9 @@ public class ConversationActivity extends XmppActivity
 				showInstallPgpDialog();
 			}
 		} else {
-			selectPresenceToAttachFile(attachmentChoice,encryption);
+			if (encryption != Message.ENCRYPTION_AXOLOTL || !trustKeysIfNeeded(REQUEST_TRUST_KEYS_MENU, attachmentChoice)) {
+				selectPresenceToAttachFile(attachmentChoice, encryption);
+			}
 		}
 	}
 
@@ -962,18 +968,23 @@ public class ConversationActivity extends XmppActivity
 			this.mConversationFragment.reInit(getSelectedConversation());
 		}
 
-		for(Iterator<Uri> i = mPendingImageUris.iterator(); i.hasNext(); i.remove()) {
-			attachImageToConversation(getSelectedConversation(),i.next());
-		}
+		if(!forbidProcessingPendings) {
+			for (Iterator<Uri> i = mPendingImageUris.iterator(); i.hasNext(); i.remove()) {
+				Uri foo = i.next();
+				attachImageToConversation(getSelectedConversation(), foo);
+			}
 
-		for(Iterator<Uri> i = mPendingFileUris.iterator(); i.hasNext(); i.remove()) {
-			attachFileToConversation(getSelectedConversation(),i.next());
-		}
+			for (Iterator<Uri> i = mPendingFileUris.iterator(); i.hasNext(); i.remove()) {
+				attachFileToConversation(getSelectedConversation(), i.next());
+			}
 
-		if (mPendingGeoUri != null) {
-			attachLocationToConversation(getSelectedConversation(), mPendingGeoUri);
-			mPendingGeoUri = null;
+			if (mPendingGeoUri != null) {
+				attachLocationToConversation(getSelectedConversation(), mPendingGeoUri);
+				mPendingGeoUri = null;
+			}
 		}
+		forbidProcessingPendings = false;
+
 		ExceptionHelper.checkForCrash(this, this.xmppConnectionService);
 		setIntent(new Intent());
 	}
@@ -1083,6 +1094,9 @@ public class ConversationActivity extends XmppActivity
 					attachLocationToConversation(getSelectedConversation(), mPendingGeoUri);
 					this.mPendingGeoUri = null;
 				}
+			} else if (requestCode == REQUEST_TRUST_KEYS_TEXT || requestCode == REQUEST_TRUST_KEYS_MENU) {
+				this.forbidProcessingPendings = !xmppConnectionServiceBound;
+				mConversationFragment.onActivityResult(requestCode, resultCode, data);
 			}
 		} else {
 			mPendingImageUris.clear();
@@ -1235,6 +1249,26 @@ public class ConversationActivity extends XmppActivity
 		return getPreferences().getBoolean("indicate_received", false);
 	}
 
+	protected boolean trustKeysIfNeeded(int requestCode) {
+		return trustKeysIfNeeded(requestCode, ATTACHMENT_CHOICE_INVALID);
+	}
+
+	protected boolean trustKeysIfNeeded(int requestCode, int attachmentChoice) {
+		AxolotlService axolotlService = mSelectedConversation.getAccount().getAxolotlService();
+		if(!axolotlService.getPendingKeys(mSelectedConversation.getContact()).isEmpty()
+				|| !axolotlService.findDevicesWithoutSession(mSelectedConversation).isEmpty()) {
+			axolotlService.createSessionsIfNeeded(mSelectedConversation, false);
+			Intent intent = new Intent(getApplicationContext(), TrustKeysActivity.class);
+			intent.putExtra("contact", mSelectedConversation.getContact().getJid().toBareJid().toString());
+			intent.putExtra("account", mSelectedConversation.getAccount().getJid().toBareJid().toString());
+			intent.putExtra("choice", attachmentChoice);
+			startActivityForResult(intent, requestCode);
+			return true;
+		} else {
+			return false;
+		}
+	}
+
 	@Override
 	protected void refreshUiReal() {
 		updateConversationList();
diff --git a/src/main/java/eu/siacs/conversations/ui/ConversationFragment.java b/src/main/java/eu/siacs/conversations/ui/ConversationFragment.java
index 026c74ad..15491dea 100644
--- a/src/main/java/eu/siacs/conversations/ui/ConversationFragment.java
+++ b/src/main/java/eu/siacs/conversations/ui/ConversationFragment.java
@@ -1,5 +1,6 @@
 package eu.siacs.conversations.ui;
 
+import android.app.Activity;
 import android.app.AlertDialog;
 import android.app.Fragment;
 import android.app.PendingIntent;
@@ -11,6 +12,7 @@ import android.content.IntentSender;
 import android.content.IntentSender.SendIntentException;
 import android.os.Bundle;
 import android.text.InputType;
+import android.util.Log;
 import android.view.ContextMenu;
 import android.view.ContextMenu.ContextMenuInfo;
 import android.view.Gravity;
@@ -43,6 +45,7 @@ import java.util.concurrent.ConcurrentLinkedQueue;
 import eu.siacs.conversations.Config;
 import eu.siacs.conversations.R;
 import eu.siacs.conversations.crypto.PgpEngine;
+import eu.siacs.conversations.crypto.axolotl.AxolotlService;
 import eu.siacs.conversations.entities.Account;
 import eu.siacs.conversations.entities.Contact;
 import eu.siacs.conversations.entities.Conversation;
@@ -304,7 +307,9 @@ public class ConversationFragment extends Fragment implements EditMessage.Keyboa
 		} else if (conversation.getNextEncryption(activity.forceEncryption()) == Message.ENCRYPTION_PGP) {
 			sendPgpMessage(message);
 		} else if (conversation.getNextEncryption(activity.forceEncryption()) == Message.ENCRYPTION_AXOLOTL) {
-			sendAxolotlMessage(message);
+			if(!activity.trustKeysIfNeeded(ConversationActivity.REQUEST_TRUST_KEYS_TEXT)) {
+				sendAxolotlMessage(message);
+			}
 		} else {
 			sendPlainTextMessage(message);
 		}
@@ -1128,7 +1133,6 @@ public class ConversationFragment extends Fragment implements EditMessage.Keyboa
 	protected void sendAxolotlMessage(final Message message) {
 		final ConversationActivity activity = (ConversationActivity) getActivity();
 		final XmppConnectionService xmppService = activity.xmppConnectionService;
-		//message.setCounterpart(conversation.getNextCounterpart());
 		xmppService.sendMessage(message);
 		messageSent();
 	}
@@ -1195,4 +1199,19 @@ public class ConversationFragment extends Fragment implements EditMessage.Keyboa
 		updateSendButton();
 	}
 
+	@Override
+	public void onActivityResult(int requestCode, int resultCode,
+	                                final Intent data) {
+		if (resultCode == Activity.RESULT_OK) {
+			if (requestCode == ConversationActivity.REQUEST_TRUST_KEYS_TEXT) {
+				final String body = mEditMessage.getText().toString();
+				Message message = new Message(conversation, body, conversation.getNextEncryption(activity.forceEncryption()));
+				sendAxolotlMessage(message);
+			} else if (requestCode == ConversationActivity.REQUEST_TRUST_KEYS_MENU) {
+				int choice = data.getIntExtra("choice", ConversationActivity.ATTACHMENT_CHOICE_INVALID);
+				activity.selectPresenceToAttachFile(choice, conversation.getNextEncryption(activity.forceEncryption()));
+			}
+		}
+	}
+
 }
diff --git a/src/main/java/eu/siacs/conversations/ui/TrustKeysActivity.java b/src/main/java/eu/siacs/conversations/ui/TrustKeysActivity.java
new file mode 100644
index 00000000..4efa4f6c
--- /dev/null
+++ b/src/main/java/eu/siacs/conversations/ui/TrustKeysActivity.java
@@ -0,0 +1,237 @@
+package eu.siacs.conversations.ui;
+
+import android.content.Intent;
+import android.os.Bundle;
+import android.util.Log;
+import android.view.View;
+import android.view.View.OnClickListener;
+import android.widget.Button;
+import android.widget.CompoundButton;
+import android.widget.LinearLayout;
+import android.widget.TextView;
+
+import org.whispersystems.libaxolotl.IdentityKey;
+
+
+import java.util.HashMap;
+import java.util.Map;
+import java.util.Set;
+
+import eu.siacs.conversations.Config;
+import eu.siacs.conversations.R;
+import eu.siacs.conversations.crypto.axolotl.AxolotlService;
+import eu.siacs.conversations.crypto.axolotl.AxolotlService.SQLiteAxolotlStore.Trust;
+import eu.siacs.conversations.entities.Account;
+import eu.siacs.conversations.entities.Contact;
+import eu.siacs.conversations.entities.Conversation;
+import eu.siacs.conversations.xmpp.OnNewKeysAvailable;
+import eu.siacs.conversations.xmpp.jid.InvalidJidException;
+import eu.siacs.conversations.xmpp.jid.Jid;
+
+public class TrustKeysActivity extends XmppActivity implements OnNewKeysAvailable {
+	private Jid accountJid;
+	private Jid contactJid;
+
+	private Contact contact;
+	private TextView ownKeysTitle;
+	private LinearLayout ownKeys;
+	private LinearLayout ownKeysCard;
+	private TextView foreignKeysTitle;
+	private LinearLayout foreignKeys;
+	private LinearLayout foreignKeysCard;
+	private Button mSaveButton;
+	private Button mCancelButton;
+
+	private final Map<IdentityKey, Boolean> ownKeysToTrust = new HashMap<>();
+	private final Map<IdentityKey, Boolean> foreignKeysToTrust = new HashMap<>();
+
+	private final OnClickListener mSaveButtonListener = new OnClickListener() {
+		@Override
+		public void onClick(View v) {
+			commitTrusts();
+			Intent data = new Intent();
+			data.putExtra("choice", getIntent().getIntExtra("choice", ConversationActivity.ATTACHMENT_CHOICE_INVALID));
+			setResult(RESULT_OK, data);
+			finish();
+		}
+	};
+
+	private final OnClickListener mCancelButtonListener = new OnClickListener() {
+		@Override
+		public void onClick(View v) {
+			setResult(RESULT_CANCELED);
+			finish();
+		}
+	};
+
+	@Override
+	protected void refreshUiReal() {
+		invalidateOptionsMenu();
+		populateView();
+	}
+
+	@Override
+	protected String getShareableUri() {
+		if (contact != null) {
+			return contact.getShareableUri();
+		} else {
+			return "";
+		}
+	}
+
+	@Override
+	protected void onCreate(final Bundle savedInstanceState) {
+		super.onCreate(savedInstanceState);
+		setContentView(R.layout.activity_trust_keys);
+		try {
+			this.accountJid = Jid.fromString(getIntent().getExtras().getString("account"));
+		} catch (final InvalidJidException ignored) {
+		}
+		try {
+			this.contactJid = Jid.fromString(getIntent().getExtras().getString("contact"));
+		} catch (final InvalidJidException ignored) {
+		}
+
+		ownKeysTitle = (TextView) findViewById(R.id.own_keys_title);
+		ownKeys = (LinearLayout) findViewById(R.id.own_keys_details);
+		ownKeysCard = (LinearLayout) findViewById(R.id.own_keys_card);
+		foreignKeysTitle = (TextView) findViewById(R.id.foreign_keys_title);
+		foreignKeys = (LinearLayout) findViewById(R.id.foreign_keys_details);
+		foreignKeysCard = (LinearLayout) findViewById(R.id.foreign_keys_card);
+		mCancelButton = (Button) findViewById(R.id.cancel_button);
+		mCancelButton.setOnClickListener(mCancelButtonListener);
+		mSaveButton = (Button) findViewById(R.id.save_button);
+		mSaveButton.setOnClickListener(mSaveButtonListener);
+
+
+		if (getActionBar() != null) {
+			getActionBar().setHomeButtonEnabled(true);
+			getActionBar().setDisplayHomeAsUpEnabled(true);
+		}
+	}
+
+	private void populateView() {
+		setTitle(getString(R.string.trust_keys));
+		ownKeys.removeAllViews();
+		foreignKeys.removeAllViews();
+		boolean hasOwnKeys = false;
+		boolean hasForeignKeys = false;
+		for(final IdentityKey identityKey : ownKeysToTrust.keySet()) {
+			hasOwnKeys = true;
+			addFingerprintRowWithListeners(ownKeys, contact.getAccount(), identityKey,
+					Trust.fromBoolean(ownKeysToTrust.get(identityKey)), false,
+					new CompoundButton.OnCheckedChangeListener() {
+						@Override
+						public void onCheckedChanged(CompoundButton buttonView, boolean isChecked) {
+							ownKeysToTrust.put(identityKey, isChecked);
+							refreshUi();
+							xmppConnectionService.updateAccountUi();
+							xmppConnectionService.updateConversationUi();
+						}
+					},
+					null
+			);
+		}
+		for(final IdentityKey identityKey : foreignKeysToTrust.keySet()) {
+			hasForeignKeys = true;
+			addFingerprintRowWithListeners(foreignKeys, contact.getAccount(), identityKey,
+					Trust.fromBoolean(foreignKeysToTrust.get(identityKey)), false,
+					new CompoundButton.OnCheckedChangeListener() {
+						@Override
+						public void onCheckedChanged(CompoundButton buttonView, boolean isChecked) {
+							foreignKeysToTrust.put(identityKey, isChecked);
+							refreshUi();
+							xmppConnectionService.updateAccountUi();
+							xmppConnectionService.updateConversationUi();
+						}
+					},
+					null
+			);
+		}
+
+		if(hasOwnKeys) {
+			ownKeysTitle.setText(accountJid.toString());
+			ownKeysCard.setVisibility(View.VISIBLE);
+		}
+		if(hasForeignKeys) {
+			foreignKeysTitle.setText(contactJid.toString());
+			foreignKeysCard.setVisibility(View.VISIBLE);
+		}
+	}
+
+	private void getFingerprints(final Account account) {
+		Set<IdentityKey> ownKeysSet = account.getAxolotlService().getPendingKeys();
+		for(final IdentityKey identityKey : ownKeysSet) {
+			if(!ownKeysToTrust.containsKey(identityKey)) {
+				ownKeysToTrust.put(identityKey, false);
+			}
+		}
+		Set<IdentityKey> foreignKeysSet = account.getAxolotlService().getPendingKeys(contact);
+		for(final IdentityKey identityKey : foreignKeysSet) {
+			if(!foreignKeysToTrust.containsKey(identityKey)) {
+				foreignKeysToTrust.put(identityKey, false);
+			}
+		}
+	}
+
+	@Override
+	public void onBackendConnected() {
+		if ((accountJid != null) && (contactJid != null)) {
+			final Account account = xmppConnectionService
+				.findAccountByJid(accountJid);
+			if (account == null) {
+				return;
+			}
+			this.contact = account.getRoster().getContact(contactJid);
+			ownKeysToTrust.clear();
+			foreignKeysToTrust.clear();
+			getFingerprints(account);
+
+			Conversation conversation = xmppConnectionService.findOrCreateConversation(account, contactJid, false);
+			if(account.getAxolotlService().hasPendingKeyFetches(conversation)) {
+				lock();
+			}
+
+			populateView();
+		}
+	}
+
+	@Override
+	public void onNewKeysAvailable() {
+		runOnUiThread(new Runnable() {
+			@Override
+			public void run() {
+				final Account account = xmppConnectionService
+						.findAccountByJid(accountJid);
+				unlock();
+				getFingerprints(account);
+				refreshUi();
+			}
+		});
+	}
+
+	private void commitTrusts() {
+		for(IdentityKey identityKey:ownKeysToTrust.keySet()) {
+			contact.getAccount().getAxolotlService().setFingerprintTrust(
+					identityKey.getFingerprint().replaceAll("\\s", ""),
+					Trust.fromBoolean(ownKeysToTrust.get(identityKey)));
+		}
+		for(IdentityKey identityKey:foreignKeysToTrust.keySet()) {
+			contact.getAccount().getAxolotlService().setFingerprintTrust(
+					identityKey.getFingerprint().replaceAll("\\s", ""),
+					Trust.fromBoolean(foreignKeysToTrust.get(identityKey)));
+		}
+	}
+
+	private void unlock() {
+		mSaveButton.setEnabled(true);
+		mSaveButton.setText(getString(R.string.done));
+		mSaveButton.setTextColor(getPrimaryTextColor());
+	}
+
+	private void lock() {
+		mSaveButton.setEnabled(false);
+		mSaveButton.setText(getString(R.string.fetching_keys));
+		mSaveButton.setTextColor(getSecondaryTextColor());
+	}
+}
diff --git a/src/main/java/eu/siacs/conversations/ui/XmppActivity.java b/src/main/java/eu/siacs/conversations/ui/XmppActivity.java
index 9dfece2f..00322452 100644
--- a/src/main/java/eu/siacs/conversations/ui/XmppActivity.java
+++ b/src/main/java/eu/siacs/conversations/ui/XmppActivity.java
@@ -84,6 +84,7 @@ import eu.siacs.conversations.services.XmppConnectionService.XmppConnectionBinde
 import eu.siacs.conversations.ui.widget.Switch;
 import eu.siacs.conversations.utils.CryptoHelper;
 import eu.siacs.conversations.utils.ExceptionHelper;
+import eu.siacs.conversations.xmpp.OnNewKeysAvailable;
 import eu.siacs.conversations.xmpp.OnUpdateBlocklist;
 import eu.siacs.conversations.xmpp.jid.InvalidJidException;
 import eu.siacs.conversations.xmpp.jid.Jid;
@@ -296,6 +297,9 @@ public abstract class XmppActivity extends Activity {
 		if (this instanceof XmppConnectionService.OnShowErrorToast) {
 			this.xmppConnectionService.setOnShowErrorToastListener((XmppConnectionService.OnShowErrorToast) this);
 		}
+		if (this instanceof OnNewKeysAvailable) {
+			this.xmppConnectionService.setOnNewKeysAvailableListener((OnNewKeysAvailable) this);
+		}
 	}
 
 	protected void unregisterListeners() {
@@ -317,6 +321,9 @@ public abstract class XmppActivity extends Activity {
 		if (this instanceof XmppConnectionService.OnShowErrorToast) {
 			this.xmppConnectionService.removeOnShowErrorToastListener();
 		}
+		if (this instanceof OnNewKeysAvailable) {
+			this.xmppConnectionService.removeOnNewKeysAvailableListener();
+		}
 	}
 
 	@Override
@@ -452,7 +459,7 @@ public abstract class XmppActivity extends Activity {
 
 					@Override
 					public void userInputRequried(PendingIntent pi,
-												  Account account) {
+					                              Account account) {
 						try {
 							startIntentSenderForResult(pi.getIntentSender(),
 									REQUEST_ANNOUNCE_PGP, null, 0, 0, 0);
diff --git a/src/main/java/eu/siacs/conversations/xmpp/OnNewKeysAvailable.java b/src/main/java/eu/siacs/conversations/xmpp/OnNewKeysAvailable.java
new file mode 100644
index 00000000..59dc1c1e
--- /dev/null
+++ b/src/main/java/eu/siacs/conversations/xmpp/OnNewKeysAvailable.java
@@ -0,0 +1,5 @@
+package eu.siacs.conversations.xmpp;
+
+public interface OnNewKeysAvailable {
+	public void onNewKeysAvailable();
+}
diff --git a/src/main/res/layout/activity_trust_keys.xml b/src/main/res/layout/activity_trust_keys.xml
new file mode 100644
index 00000000..c535d51d
--- /dev/null
+++ b/src/main/res/layout/activity_trust_keys.xml
@@ -0,0 +1,120 @@
+<?xml version="1.0" encoding="utf-8"?>
+<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
+                xmlns:tools="http://schemas.android.com/tools"
+                android:layout_width="match_parent"
+                android:layout_height="match_parent"
+                android:background="@color/grey200" >
+    <ScrollView
+        android:layout_width="fill_parent"
+        android:layout_height="wrap_content"
+        android:layout_above="@+id/button_bar"
+        android:layout_alignParentTop="true" >
+
+        <LinearLayout
+            android:layout_width="match_parent"
+            android:layout_height="wrap_content"
+            android:orientation="vertical">
+
+            <LinearLayout
+                android:id="@+id/own_keys_card"
+                android:layout_width="fill_parent"
+                android:layout_height="wrap_content"
+                android:layout_marginLeft="@dimen/activity_horizontal_margin"
+                android:layout_marginRight="@dimen/activity_horizontal_margin"
+                android:layout_marginTop="@dimen/activity_vertical_margin"
+                android:layout_marginBottom="@dimen/activity_vertical_margin"
+                android:background="@drawable/infocard_border"
+                android:orientation="vertical"
+                android:padding="@dimen/infocard_padding"
+                android:visibility="gone">
+
+                <TextView
+                    android:id="@+id/own_keys_title"
+                    android:layout_width="wrap_content"
+                    android:layout_height="wrap_content"
+                    android:textColor="@color/black87"
+                    android:textSize="?attr/TextSizeHeadline"
+                    android:textStyle="bold"/>
+
+                <LinearLayout
+                    android:id="@+id/own_keys_details"
+                    android:layout_width="fill_parent"
+                    android:layout_height="wrap_content"
+                    android:divider="?android:dividerHorizontal"
+                    android:showDividers="middle"
+                    android:orientation="vertical">
+                </LinearLayout>
+
+            </LinearLayout>
+
+            <LinearLayout
+                android:id="@+id/foreign_keys_card"
+                android:layout_width="fill_parent"
+                android:layout_height="wrap_content"
+                android:layout_marginLeft="@dimen/activity_horizontal_margin"
+                android:layout_marginRight="@dimen/activity_horizontal_margin"
+                android:layout_marginTop="@dimen/activity_vertical_margin"
+                android:layout_marginBottom="@dimen/activity_vertical_margin"
+                android:background="@drawable/infocard_border"
+                android:orientation="vertical"
+                android:padding="@dimen/infocard_padding"
+                android:visibility="gone">
+
+                <TextView
+                    android:id="@+id/foreign_keys_title"
+                    android:layout_width="wrap_content"
+                    android:layout_height="wrap_content"
+                    android:textColor="@color/black87"
+                    android:textSize="?attr/TextSizeHeadline"
+                    android:textStyle="bold"/>
+
+                <LinearLayout
+                    android:id="@+id/foreign_keys_details"
+                    android:layout_width="fill_parent"
+                    android:layout_height="wrap_content"
+                    android:divider="?android:dividerHorizontal"
+                    android:showDividers="middle"
+                    android:orientation="vertical">
+                </LinearLayout>
+
+            </LinearLayout>
+
+        </LinearLayout>
+    </ScrollView>
+    <LinearLayout
+        android:id="@+id/button_bar"
+        android:layout_width="wrap_content"
+        android:layout_height="wrap_content"
+        android:layout_alignParentBottom="true"
+        android:layout_alignParentStart="true"
+        android:layout_alignParentEnd="true"
+        android:layout_alignParentLeft="true"
+        android:layout_alignParentRight="true" >
+
+        <Button
+            android:id="@+id/cancel_button"
+            style="?android:attr/borderlessButtonStyle"
+            android:layout_width="0dp"
+            android:layout_height="wrap_content"
+            android:layout_weight="1"
+            android:text="@string/cancel"
+            android:textColor="@color/black87" />
+
+        <View
+            android:layout_width="1dp"
+            android:layout_height="fill_parent"
+            android:layout_marginBottom="7dp"
+            android:layout_marginTop="7dp"
+            android:background="@color/black12" />
+
+        <Button
+            android:id="@+id/save_button"
+            style="?android:attr/borderlessButtonStyle"
+            android:layout_width="0dp"
+            android:layout_height="wrap_content"
+            android:layout_weight="1"
+            android:enabled="true"
+            android:textColor="@color/black54"
+            android:text="@string/done"/>
+    </LinearLayout>
+</RelativeLayout>
diff --git a/src/main/res/values/strings.xml b/src/main/res/values/strings.xml
index f4c75ee1..8537c118 100644
--- a/src/main/res/values/strings.xml
+++ b/src/main/res/values/strings.xml
@@ -211,6 +211,9 @@
 	<string name="axolotl_fingerprint">Axolotl fingerprint</string>
 	<string name="this_device_axolotl_fingerprint">Own Axolotl fingerprint</string>
 	<string name="other_devices">Other devices</string>
+	<string name="trust_keys">Trust Axolotl Keys</string>
+	<string name="fetching_keys">Fetching keys...</string>
+	<string name="done">Done</string>
 	<string name="axolotl_devicelist">Other own Axolotl Devices</string>
 	<string name="verify">Verify</string>
 	<string name="decrypt">Decrypt</string>