Merge branch 'trz/rebase' into trz/rename

2 files changed, 798 insertions, 163 deletions

diff --git a/src/main/java/de/thedevstack/conversationsplus/persistance/DatabaseBackend.java b/src/main/java/de/thedevstack/conversationsplus/persistance/DatabaseBackend.java
index 5b09fe2e..52f60e88 100644
--- a/src/main/java/de/thedevstack/conversationsplus/persistance/DatabaseBackend.java
+++ b/src/main/java/de/thedevstack/conversationsplus/persistance/DatabaseBackend.java
@@ -1,31 +1,58 @@
 package de.thedevstack.conversationsplus.persistance;
 
+import android.content.ContentValues;
+import android.content.Context;
+import android.database.Cursor;
+import android.database.DatabaseUtils;
+import android.database.sqlite.SQLiteCantOpenDatabaseException;
+import android.database.sqlite.SQLiteDatabase;
+import android.database.sqlite.SQLiteOpenHelper;
+import android.util.Base64;
+import android.util.Log;
+import android.util.Pair;
+
+import org.whispersystems.libaxolotl.AxolotlAddress;
+import org.whispersystems.libaxolotl.IdentityKey;
+import org.whispersystems.libaxolotl.IdentityKeyPair;
+import org.whispersystems.libaxolotl.InvalidKeyException;
+import org.whispersystems.libaxolotl.state.PreKeyRecord;
+import org.whispersystems.libaxolotl.state.SessionRecord;
+import org.whispersystems.libaxolotl.state.SignedPreKeyRecord;
+
+import java.io.ByteArrayInputStream;
+import java.io.IOException;
+import java.security.cert.CertificateEncodingException;
+import java.security.cert.CertificateException;
+import java.security.cert.CertificateFactory;
+import java.security.cert.X509Certificate;
 import java.util.ArrayList;
+import java.util.HashSet;
+import java.util.Iterator;
 import java.util.List;
+import java.util.Set;
 import java.util.concurrent.CopyOnWriteArrayList;
+import org.json.JSONException;
 
 import de.thedevstack.android.logcat.Logging;
 import de.thedevstack.conversationsplus.Config;
+import de.thedevstack.conversationsplus.crypto.axolotl.AxolotlServiceImpl;
+import de.thedevstack.conversationsplus.crypto.axolotl.SQLiteAxolotlStore;
+import de.thedevstack.conversationsplus.crypto.axolotl.XmppAxolotlSession;
 import de.thedevstack.conversationsplus.entities.Account;
 import de.thedevstack.conversationsplus.entities.Contact;
 import de.thedevstack.conversationsplus.entities.Conversation;
 import de.thedevstack.conversationsplus.entities.Message;
 import de.thedevstack.conversationsplus.entities.Roster;
+import de.thedevstack.conversationsplus.entities.ServiceDiscoveryResult;
 import de.thedevstack.conversationsplus.xmpp.jid.InvalidJidException;
 import de.thedevstack.conversationsplus.xmpp.jid.Jid;
 
-import android.content.Context;
-import android.database.Cursor;
-import android.database.sqlite.SQLiteCantOpenDatabaseException;
-import android.database.sqlite.SQLiteDatabase;
-import android.database.sqlite.SQLiteOpenHelper;
-
 public class DatabaseBackend extends SQLiteOpenHelper {
 
 	private static DatabaseBackend instance = null;
 
 	private static final String DATABASE_NAME = "history";
-	private static final int DATABASE_VERSION = 14;
+	private static final int DATABASE_VERSION = 24;
 
 	private static String CREATE_CONTATCS_STATEMENT = "create table "
 			+ Contact.TABLENAME + "(" + Contact.ACCOUNT + " TEXT, "
@@ -33,12 +60,75 @@ public class DatabaseBackend extends SQLiteOpenHelper {
 			+ Contact.JID + " TEXT," + Contact.KEYS + " TEXT,"
 			+ Contact.PHOTOURI + " TEXT," + Contact.OPTIONS + " NUMBER,"
 			+ Contact.SYSTEMACCOUNT + " NUMBER, " + Contact.AVATAR + " TEXT, "
-            + Contact.LAST_PRESENCE + " TEXT, " + Contact.LAST_TIME + " NUMBER, "
+			+ Contact.LAST_PRESENCE + " TEXT, " + Contact.LAST_TIME + " NUMBER, "
 			+ Contact.GROUPS + " TEXT, FOREIGN KEY(" + Contact.ACCOUNT + ") REFERENCES "
 			+ Account.TABLENAME + "(" + Account.UUID
 			+ ") ON DELETE CASCADE, UNIQUE(" + Contact.ACCOUNT + ", "
 			+ Contact.JID + ") ON CONFLICT REPLACE);";
 
+	private static String CREATE_DISCOVERY_RESULTS_STATEMENT = "create table "
+			+ ServiceDiscoveryResult.TABLENAME + "("
+			+ ServiceDiscoveryResult.HASH + " TEXT, "
+			+ ServiceDiscoveryResult.VER + " TEXT, "
+			+ ServiceDiscoveryResult.RESULT + " TEXT, "
+			+ "UNIQUE(" + ServiceDiscoveryResult.HASH + ", "
+			+ ServiceDiscoveryResult.VER + ") ON CONFLICT REPLACE);";
+
+	private static String CREATE_PREKEYS_STATEMENT = "CREATE TABLE "
+			+ SQLiteAxolotlStore.PREKEY_TABLENAME + "("
+			+ SQLiteAxolotlStore.ACCOUNT + " TEXT,  "
+			+ SQLiteAxolotlStore.ID + " INTEGER, "
+			+ SQLiteAxolotlStore.KEY + " TEXT, FOREIGN KEY("
+			+ SQLiteAxolotlStore.ACCOUNT
+			+ ") REFERENCES " + Account.TABLENAME + "(" + Account.UUID + ") ON DELETE CASCADE, "
+			+ "UNIQUE( " + SQLiteAxolotlStore.ACCOUNT + ", "
+			+ SQLiteAxolotlStore.ID
+			+ ") ON CONFLICT REPLACE"
+			+ ");";
+
+	private static String CREATE_SIGNED_PREKEYS_STATEMENT = "CREATE TABLE "
+			+ SQLiteAxolotlStore.SIGNED_PREKEY_TABLENAME + "("
+			+ SQLiteAxolotlStore.ACCOUNT + " TEXT,  "
+			+ SQLiteAxolotlStore.ID + " INTEGER, "
+			+ SQLiteAxolotlStore.KEY + " TEXT, FOREIGN KEY("
+			+ SQLiteAxolotlStore.ACCOUNT
+			+ ") REFERENCES " + Account.TABLENAME + "(" + Account.UUID + ") ON DELETE CASCADE, "
+			+ "UNIQUE( " + SQLiteAxolotlStore.ACCOUNT + ", "
+			+ SQLiteAxolotlStore.ID
+			+ ") ON CONFLICT REPLACE" +
+			");";
+
+	private static String CREATE_SESSIONS_STATEMENT = "CREATE TABLE "
+			+ SQLiteAxolotlStore.SESSION_TABLENAME + "("
+			+ SQLiteAxolotlStore.ACCOUNT + " TEXT,  "
+			+ SQLiteAxolotlStore.NAME + " TEXT, "
+			+ SQLiteAxolotlStore.DEVICE_ID + " INTEGER, "
+			+ SQLiteAxolotlStore.KEY + " TEXT, FOREIGN KEY("
+			+ SQLiteAxolotlStore.ACCOUNT
+			+ ") REFERENCES " + Account.TABLENAME + "(" + Account.UUID + ") ON DELETE CASCADE, "
+			+ "UNIQUE( " + SQLiteAxolotlStore.ACCOUNT + ", "
+			+ SQLiteAxolotlStore.NAME + ", "
+			+ SQLiteAxolotlStore.DEVICE_ID
+			+ ") ON CONFLICT REPLACE"
+			+ ");";
+
+	private static String CREATE_IDENTITIES_STATEMENT = "CREATE TABLE "
+			+ SQLiteAxolotlStore.IDENTITIES_TABLENAME + "("
+			+ SQLiteAxolotlStore.ACCOUNT + " TEXT,  "
+			+ SQLiteAxolotlStore.NAME + " TEXT, "
+			+ SQLiteAxolotlStore.OWN + " INTEGER, "
+			+ SQLiteAxolotlStore.FINGERPRINT + " TEXT, "
+			+ SQLiteAxolotlStore.CERTIFICATE + " BLOB, "
+			+ SQLiteAxolotlStore.TRUSTED + " INTEGER, "
+			+ SQLiteAxolotlStore.KEY + " TEXT, FOREIGN KEY("
+			+ SQLiteAxolotlStore.ACCOUNT
+			+ ") REFERENCES " + Account.TABLENAME + "(" + Account.UUID + ") ON DELETE CASCADE, "
+			+ "UNIQUE( " + SQLiteAxolotlStore.ACCOUNT + ", "
+			+ SQLiteAxolotlStore.NAME + ", "
+			+ SQLiteAxolotlStore.FINGERPRINT
+			+ ") ON CONFLICT IGNORE"
+			+ ");";
+
 	private DatabaseBackend(Context context) {
 		super(context, DATABASE_NAME, null, DATABASE_VERSION);
 	}
@@ -49,9 +139,10 @@ public class DatabaseBackend extends SQLiteOpenHelper {
 		db.execSQL("create table " + Account.TABLENAME + "(" + Account.UUID
 				+ " TEXT PRIMARY KEY," + Account.USERNAME + " TEXT,"
 				+ Account.SERVER + " TEXT," + Account.PASSWORD + " TEXT,"
+				+ Account.DISPLAY_NAME + " TEXT, "
 				+ Account.ROSTERVERSION + " TEXT," + Account.OPTIONS
 				+ " NUMBER, " + Account.AVATAR + " TEXT, " + Account.KEYS
-				+ " TEXT)");
+				+ " TEXT, " + Account.HOSTNAME + " TEXT, " + Account.PORT + " NUMBER DEFAULT 5222)");
 		db.execSQL("create table " + Conversation.TABLENAME + " ("
 				+ Conversation.UUID + " TEXT PRIMARY KEY, " + Conversation.NAME
 				+ " TEXT, " + Conversation.CONTACT + " TEXT, "
@@ -69,12 +160,21 @@ public class DatabaseBackend extends SQLiteOpenHelper {
 				+ Message.STATUS + " NUMBER," + Message.TYPE + " NUMBER, "
 				+ Message.RELATIVE_FILE_PATH + " TEXT, "
 				+ Message.SERVER_MSG_ID + " TEXT, "
+				+ Message.FINGERPRINT + " TEXT, "
+				+ Message.CARBON + " INTEGER, "
+				+ Message.EDITED + " TEXT, "
+				+ Message.READ + " NUMBER DEFAULT 1, "
 				+ Message.REMOTE_MSG_ID + " TEXT, FOREIGN KEY("
 				+ Message.CONVERSATION + ") REFERENCES "
 				+ Conversation.TABLENAME + "(" + Conversation.UUID
 				+ ") ON DELETE CASCADE);");
 
 		db.execSQL(CREATE_CONTATCS_STATEMENT);
+		db.execSQL(CREATE_DISCOVERY_RESULTS_STATEMENT);
+		db.execSQL(CREATE_SESSIONS_STATEMENT);
+		db.execSQL(CREATE_PREKEYS_STATEMENT);
+		db.execSQL(CREATE_SIGNED_PREKEYS_STATEMENT);
+		db.execSQL(CREATE_IDENTITIES_STATEMENT);
 	}
 
 	@Override
@@ -109,12 +209,12 @@ public class DatabaseBackend extends SQLiteOpenHelper {
 			db.execSQL("ALTER TABLE " + Conversation.TABLENAME + " ADD COLUMN "
 					+ Conversation.ATTRIBUTES + " TEXT");
 		}
-        if (oldVersion < 9 && newVersion >= 9) {
-            db.execSQL("ALTER TABLE " + Contact.TABLENAME + " ADD COLUMN "
-                    + Contact.LAST_TIME + " NUMBER");
-            db.execSQL("ALTER TABLE " + Contact.TABLENAME + " ADD COLUMN "
-                    + Contact.LAST_PRESENCE + " TEXT");
-        }
+		if (oldVersion < 9 && newVersion >= 9) {
+			db.execSQL("ALTER TABLE " + Contact.TABLENAME + " ADD COLUMN "
+					+ Contact.LAST_TIME + " NUMBER");
+			db.execSQL("ALTER TABLE " + Contact.TABLENAME + " ADD COLUMN "
+					+ Contact.LAST_PRESENCE + " TEXT");
+		}
 		if (oldVersion < 10 && newVersion >= 10) {
 			db.execSQL("ALTER TABLE " + Message.TABLENAME + " ADD COLUMN "
 					+ Message.RELATIVE_FILE_PATH + " TEXT");
@@ -122,23 +222,23 @@ public class DatabaseBackend extends SQLiteOpenHelper {
 		if (oldVersion < 11 && newVersion >= 11) {
 			db.execSQL("ALTER TABLE " + Contact.TABLENAME + " ADD COLUMN "
 					+ Contact.GROUPS + " TEXT");
-			db.execSQL("delete from "+Contact.TABLENAME);
-			db.execSQL("update "+Account.TABLENAME+" set "+Account.ROSTERVERSION+" = NULL");
+			db.execSQL("delete from " + Contact.TABLENAME);
+			db.execSQL("update " + Account.TABLENAME + " set " + Account.ROSTERVERSION + " = NULL");
 		}
 		if (oldVersion < 12 && newVersion >= 12) {
 			db.execSQL("ALTER TABLE " + Message.TABLENAME + " ADD COLUMN "
 					+ Message.SERVER_MSG_ID + " TEXT");
 		}
 		if (oldVersion < 13 && newVersion >= 13) {
-			db.execSQL("delete from "+Contact.TABLENAME);
-			db.execSQL("update "+Account.TABLENAME+" set "+Account.ROSTERVERSION+" = NULL");
+			db.execSQL("delete from " + Contact.TABLENAME);
+			db.execSQL("update " + Account.TABLENAME + " set " + Account.ROSTERVERSION + " = NULL");
 		}
 		if (oldVersion < 14 && newVersion >= 14) {
 			// migrate db to new, canonicalized JID domainpart representation
 
 			// Conversation table
 			Cursor cursor = db.rawQuery("select * from " + Conversation.TABLENAME, new String[0]);
-			while(cursor.moveToNext()) {
+			while (cursor.moveToNext()) {
 				String newJid;
 				try {
 					newJid = Jid.fromString(
@@ -146,8 +246,8 @@ public class DatabaseBackend extends SQLiteOpenHelper {
 					).toString();
 				} catch (InvalidJidException ignored) {
 					Logging.e(Config.LOGTAG, "Failed to migrate Conversation CONTACTJID "
-							+cursor.getString(cursor.getColumnIndex(Conversation.CONTACTJID))
-							+": " + ignored +". Skipping...");
+							+ cursor.getString(cursor.getColumnIndex(Conversation.CONTACTJID))
+							+ ": " + ignored + ". Skipping...");
 					continue;
 				}
 
@@ -156,14 +256,14 @@ public class DatabaseBackend extends SQLiteOpenHelper {
 						cursor.getString(cursor.getColumnIndex(Conversation.UUID)),
 				};
 				db.execSQL("update " + Conversation.TABLENAME
-						+ " set " + Conversation.CONTACTJID	+ " = ? "
+						+ " set " + Conversation.CONTACTJID + " = ? "
 						+ " where " + Conversation.UUID + " = ?", updateArgs);
 			}
 			cursor.close();
 
 			// Contact table
 			cursor = db.rawQuery("select * from " + Contact.TABLENAME, new String[0]);
-			while(cursor.moveToNext()) {
+			while (cursor.moveToNext()) {
 				String newJid;
 				try {
 					newJid = Jid.fromString(
@@ -171,8 +271,8 @@ public class DatabaseBackend extends SQLiteOpenHelper {
 					).toString();
 				} catch (InvalidJidException ignored) {
 					Logging.e(Config.LOGTAG, "Failed to migrate Contact JID "
-							+cursor.getString(cursor.getColumnIndex(Contact.JID))
-							+": " + ignored +". Skipping...");
+							+ cursor.getString(cursor.getColumnIndex(Contact.JID))
+							+ ": " + ignored + ". Skipping...");
 					continue;
 				}
 
@@ -190,7 +290,7 @@ public class DatabaseBackend extends SQLiteOpenHelper {
 
 			// Account table
 			cursor = db.rawQuery("select * from " + Account.TABLENAME, new String[0]);
-			while(cursor.moveToNext()) {
+			while (cursor.moveToNext()) {
 				String newServer;
 				try {
 					newServer = Jid.fromParts(
@@ -200,8 +300,8 @@ public class DatabaseBackend extends SQLiteOpenHelper {
 					).getDomainpart();
 				} catch (InvalidJidException ignored) {
 					Logging.e(Config.LOGTAG, "Failed to migrate Account SERVER "
-							+cursor.getString(cursor.getColumnIndex(Account.SERVER))
-							+": " + ignored +". Skipping...");
+							+ cursor.getString(cursor.getColumnIndex(Account.SERVER))
+							+ ": " + ignored + ". Skipping...");
 					continue;
 				}
 
@@ -215,6 +315,67 @@ public class DatabaseBackend extends SQLiteOpenHelper {
 			}
 			cursor.close();
 		}
+		if (oldVersion < 15 && newVersion >= 15) {
+			recreateAxolotlDb(db);
+			db.execSQL("ALTER TABLE " + Message.TABLENAME + " ADD COLUMN "
+					+ Message.FINGERPRINT + " TEXT");
+		}
+		if (oldVersion < 16 && newVersion >= 16) {
+			db.execSQL("ALTER TABLE " + Message.TABLENAME + " ADD COLUMN "
+					+ Message.CARBON + " INTEGER");
+		}
+		if (oldVersion < 19 && newVersion >= 19) {
+			db.execSQL("ALTER TABLE " + Account.TABLENAME + " ADD COLUMN " + Account.DISPLAY_NAME + " TEXT");
+		}
+		if (oldVersion < 20 && newVersion >= 20) {
+			db.execSQL("ALTER TABLE " + Account.TABLENAME + " ADD COLUMN " + Account.HOSTNAME + " TEXT");
+			db.execSQL("ALTER TABLE " + Account.TABLENAME + " ADD COLUMN " + Account.PORT + " NUMBER DEFAULT 5222");
+		}
+		/* Any migrations that alter the Account table need to happen BEFORE this migration, as it
+		 * depends on account de-serialization.
+		 */
+		if (oldVersion < 17 && newVersion >= 17) {
+			List<Account> accounts = getAccounts(db);
+			for (Account account : accounts) {
+				String ownDeviceIdString = account.getKey(SQLiteAxolotlStore.JSONKEY_REGISTRATION_ID);
+				if (ownDeviceIdString == null) {
+					continue;
+				}
+				int ownDeviceId = Integer.valueOf(ownDeviceIdString);
+				AxolotlAddress ownAddress = new AxolotlAddress(account.getJid().toBareJid().toString(), ownDeviceId);
+				deleteSession(db, account, ownAddress);
+				IdentityKeyPair identityKeyPair = loadOwnIdentityKeyPair(db, account);
+				if (identityKeyPair != null) {
+					setIdentityKeyTrust(db, account, identityKeyPair.getPublicKey().getFingerprint().replaceAll("\\s", ""), XmppAxolotlSession.Trust.TRUSTED);
+				} else {
+					Log.d(Config.LOGTAG, account.getJid().toBareJid() + ": could not load own identity key pair");
+				}
+			}
+		}
+		if (oldVersion < 18 && newVersion >= 18) {
+			db.execSQL("ALTER TABLE " + Message.TABLENAME + " ADD COLUMN " + Message.READ + " NUMBER DEFAULT 1");
+		}
+
+		if (oldVersion < 21 && newVersion >= 21) {
+			List<Account> accounts = getAccounts(db);
+			for (Account account : accounts) {
+				account.unsetPgpSignature();
+				db.update(Account.TABLENAME, account.getContentValues(), Account.UUID
+						+ "=?", new String[]{account.getUuid()});
+			}
+		}
+
+		if (oldVersion < 22 && oldVersion >= 15 && newVersion >= 22) {
+			db.execSQL("ALTER TABLE " + SQLiteAxolotlStore.IDENTITIES_TABLENAME + " ADD COLUMN " + SQLiteAxolotlStore.CERTIFICATE);
+		}
+
+		if (oldVersion < 23 && newVersion >= 23) {
+			db.execSQL(CREATE_DISCOVERY_RESULTS_STATEMENT);
+		}
+
+		if (oldVersion < 24 && newVersion >= 24) {
+			db.execSQL("ALTER TABLE " + Message.TABLENAME + " ADD COLUMN " + Message.EDITED + " TEXT");
+		}
 	}
 
 	public static synchronized DatabaseBackend getInstance(Context context) {
@@ -239,26 +400,34 @@ public class DatabaseBackend extends SQLiteOpenHelper {
 		db.insert(Account.TABLENAME, null, account.getContentValues());
 	}
 
-	public void createContact(Contact contact) {
+	public void insertDiscoveryResult(ServiceDiscoveryResult result) {
 		SQLiteDatabase db = this.getWritableDatabase();
-		db.insert(Contact.TABLENAME, null, contact.getContentValues());
+		db.insert(ServiceDiscoveryResult.TABLENAME, null, result.getContentValues());
 	}
 
-	public int getConversationCount() {
+	public ServiceDiscoveryResult findDiscoveryResult(final String hash, final String ver) {
 		SQLiteDatabase db = this.getReadableDatabase();
-		Cursor cursor = db.rawQuery("select count(uuid) as count from "
-				+ Conversation.TABLENAME + " where " + Conversation.STATUS
-				+ "=" + Conversation.STATUS_AVAILABLE, null);
+		String[] selectionArgs = {hash, ver};
+		Cursor cursor = db.query(ServiceDiscoveryResult.TABLENAME, null,
+				ServiceDiscoveryResult.HASH + "=? AND " + ServiceDiscoveryResult.VER + "=?",
+				selectionArgs, null, null, null);
+		if (cursor.getCount() == 0)
+			return null;
 		cursor.moveToFirst();
-		int count = cursor.getInt(0);
+
+		ServiceDiscoveryResult result = null;
+		try {
+			result = new ServiceDiscoveryResult(cursor);
+		} catch (JSONException e) { /* result is still null */ }
+
 		cursor.close();
-		return count;
+		return result;
 	}
 
 	public CopyOnWriteArrayList<Conversation> getConversations(int status) {
 		CopyOnWriteArrayList<Conversation> list = new CopyOnWriteArrayList<>();
 		SQLiteDatabase db = this.getReadableDatabase();
-		String[] selectionArgs = { Integer.toString(status) };
+		String[] selectionArgs = {Integer.toString(status)};
 		Cursor cursor = db.rawQuery("select * from " + Conversation.TABLENAME
 				+ " where " + Conversation.STATUS + " = ? order by "
 				+ Conversation.CREATED + " desc", selectionArgs);
@@ -274,20 +443,20 @@ public class DatabaseBackend extends SQLiteOpenHelper {
 	}
 
 	public ArrayList<Message> getMessages(Conversation conversation, int limit,
-			long timestamp) {
+										  long timestamp) {
 		ArrayList<Message> list = new ArrayList<>();
 		SQLiteDatabase db = this.getReadableDatabase();
 		Cursor cursor;
 		if (timestamp == -1) {
-			String[] selectionArgs = { conversation.getUuid() };
+			String[] selectionArgs = {conversation.getUuid()};
 			cursor = db.query(Message.TABLENAME, null, Message.CONVERSATION
 					+ "=?", selectionArgs, null, null, Message.TIME_SENT
 					+ " DESC", String.valueOf(limit));
 		} else {
-			String[] selectionArgs = { conversation.getUuid(),
-					Long.toString(timestamp) };
+			String[] selectionArgs = {conversation.getUuid(),
+					Long.toString(timestamp)};
 			cursor = db.query(Message.TABLENAME, null, Message.CONVERSATION
-					+ "=? and " + Message.TIME_SENT + "<?", selectionArgs,
+							+ "=? and " + Message.TIME_SENT + "<?", selectionArgs,
 					null, null, Message.TIME_SENT + " DESC",
 					String.valueOf(limit));
 		}
@@ -303,15 +472,52 @@ public class DatabaseBackend extends SQLiteOpenHelper {
 		return list;
 	}
 
+	public Iterable<Message> getMessagesIterable(final Conversation conversation) {
+		return new Iterable<Message>() {
+			@Override
+			public Iterator<Message> iterator() {
+				class MessageIterator implements Iterator<Message> {
+					SQLiteDatabase db = getReadableDatabase();
+					String[] selectionArgs = {conversation.getUuid()};
+					Cursor cursor = db.query(Message.TABLENAME, null, Message.CONVERSATION
+							+ "=?", selectionArgs, null, null, Message.TIME_SENT
+							+ " ASC", null);
+
+					public MessageIterator() {
+						cursor.moveToFirst();
+					}
+
+					@Override
+					public boolean hasNext() {
+						return !cursor.isAfterLast();
+					}
+
+					@Override
+					public Message next() {
+						Message message = Message.fromCursor(cursor);
+						cursor.moveToNext();
+						return message;
+					}
+
+					@Override
+					public void remove() {
+						throw new UnsupportedOperationException();
+					}
+				}
+				return new MessageIterator();
+			}
+		};
+	}
+
 	public Conversation findConversation(final Account account, final Jid contactJid) {
 		SQLiteDatabase db = this.getReadableDatabase();
-		String[] selectionArgs = { account.getUuid(),
+		String[] selectionArgs = {account.getUuid(),
 				contactJid.toBareJid().toString() + "/%",
 				contactJid.toBareJid().toString()
-				};
+		};
 		Cursor cursor = db.query(Conversation.TABLENAME, null,
 				Conversation.ACCOUNT + "=? AND (" + Conversation.CONTACTJID
-						+ " like ? OR "+Conversation.CONTACTJID+"=?)", selectionArgs, null, null, null);
+						+ " like ? OR " + Conversation.CONTACTJID + "=?)", selectionArgs, null, null, null);
 		if (cursor.getCount() == 0)
 			return null;
 		cursor.moveToFirst();
@@ -322,14 +528,18 @@ public class DatabaseBackend extends SQLiteOpenHelper {
 
 	public void updateConversation(final Conversation conversation) {
 		final SQLiteDatabase db = this.getWritableDatabase();
-		final String[] args = { conversation.getUuid() };
+		final String[] args = {conversation.getUuid()};
 		db.update(Conversation.TABLENAME, conversation.getContentValues(),
 				Conversation.UUID + "=?", args);
 	}
 
 	public List<Account> getAccounts() {
-		List<Account> list = new ArrayList<>();
 		SQLiteDatabase db = this.getReadableDatabase();
+		return getAccounts(db);
+	}
+
+	private List<Account> getAccounts(SQLiteDatabase db) {
+		List<Account> list = new ArrayList<>();
 		Cursor cursor = db.query(Account.TABLENAME, null, null, null, null,
 				null, null);
 		while (cursor.moveToNext()) {
@@ -341,14 +551,14 @@ public class DatabaseBackend extends SQLiteOpenHelper {
 
 	public void updateAccount(Account account) {
 		SQLiteDatabase db = this.getWritableDatabase();
-		String[] args = { account.getUuid() };
+		String[] args = {account.getUuid()};
 		db.update(Account.TABLENAME, account.getContentValues(), Account.UUID
 				+ "=?", args);
 	}
 
 	public void deleteAccount(Account account) {
 		SQLiteDatabase db = this.getWritableDatabase();
-		String[] args = { account.getUuid() };
+		String[] args = {account.getUuid()};
 		db.delete(Account.TABLENAME, Account.UUID + "=?", args);
 	}
 
@@ -377,7 +587,14 @@ public class DatabaseBackend extends SQLiteOpenHelper {
 
 	public void updateMessage(Message message) {
 		SQLiteDatabase db = this.getWritableDatabase();
-		String[] args = { message.getUuid() };
+		String[] args = {message.getUuid()};
+		db.update(Message.TABLENAME, message.getContentValues(), Message.UUID
+				+ "=?", args);
+	}
+
+	public void updateMessage(Message message, String uuid) {
+		SQLiteDatabase db = this.getWritableDatabase();
+		String[] args = {uuid};
 		db.update(Message.TABLENAME, message.getContentValues(), Message.UUID
 				+ "=?", args);
 	}
@@ -385,7 +602,7 @@ public class DatabaseBackend extends SQLiteOpenHelper {
 	public void readRoster(Roster roster) {
 		SQLiteDatabase db = this.getReadableDatabase();
 		Cursor cursor;
-		String args[] = { roster.getAccount().getUuid() };
+		String args[] = {roster.getAccount().getUuid()};
 		cursor = db.query(Contact.TABLENAME, null, Contact.ACCOUNT + "=?", args, null, null, null);
 		while (cursor.moveToNext()) {
 			roster.initContact(Contact.fromCursor(cursor));
@@ -396,89 +613,517 @@ public class DatabaseBackend extends SQLiteOpenHelper {
 	public void writeRoster(final Roster roster) {
 		final Account account = roster.getAccount();
 		final SQLiteDatabase db = this.getWritableDatabase();
+		db.beginTransaction();
 		for (Contact contact : roster.getContacts()) {
 			if (contact.getOption(Contact.Options.IN_ROSTER)) {
 				db.insert(Contact.TABLENAME, null, contact.getContentValues());
 			} else {
 				String where = Contact.ACCOUNT + "=? AND " + Contact.JID + "=?";
-				String[] whereArgs = { account.getUuid(), contact.getJid().toString() };
+				String[] whereArgs = {account.getUuid(), contact.getJid().toString()};
 				db.delete(Contact.TABLENAME, where, whereArgs);
 			}
 		}
+		db.setTransactionSuccessful();
+		db.endTransaction();
 		account.setRosterVersion(roster.getVersion());
 		updateAccount(account);
 	}
 
-	public void deleteMessage(Message message) {
-		SQLiteDatabase db = this.getWritableDatabase();
-		String[] args = { message.getUuid() };
-		db.delete(Message.TABLENAME, Message.UUID + "=?", args);
-	}
-
 	public void deleteMessagesInConversation(Conversation conversation) {
 		SQLiteDatabase db = this.getWritableDatabase();
-		String[] args = { conversation.getUuid() };
+		String[] args = {conversation.getUuid()};
 		db.delete(Message.TABLENAME, Message.CONVERSATION + "=?", args);
 	}
 
-	public Conversation findConversationByUuid(String conversationUuid) {
-		SQLiteDatabase db = this.getReadableDatabase();
-		String[] selectionArgs = { conversationUuid };
-		Cursor cursor = db.query(Conversation.TABLENAME, null,
-				Conversation.UUID + "=?", selectionArgs, null, null, null);
-		if (cursor.getCount() == 0) {
+	public Pair<Long, String> getLastMessageReceived(Account account) {
+		try {
+			SQLiteDatabase db = this.getReadableDatabase();
+			String sql = "select messages.timeSent,messages.serverMsgId from accounts join conversations on accounts.uuid=conversations.accountUuid join messages on conversations.uuid=messages.conversationUuid where accounts.uuid=? and (messages.status=0 or messages.carbon=1 or messages.serverMsgId not null) order by messages.timesent desc limit 1";
+			String[] args = {account.getUuid()};
+			Cursor cursor = db.rawQuery(sql, args);
+			if (cursor.getCount() == 0) {
+				return null;
+			} else {
+				cursor.moveToFirst();
+				return new Pair<>(cursor.getLong(0), cursor.getString(1));
+			}
+		} catch (Exception e) {
 			return null;
 		}
-		cursor.moveToFirst();
-		Conversation conversation = Conversation.fromCursor(cursor);
+	}
+
+	private Cursor getCursorForSession(Account account, AxolotlAddress contact) {
+		final SQLiteDatabase db = this.getReadableDatabase();
+		String[] columns = null;
+		String[] selectionArgs = {account.getUuid(),
+				contact.getName(),
+				Integer.toString(contact.getDeviceId())};
+		Cursor cursor = db.query(SQLiteAxolotlStore.SESSION_TABLENAME,
+				columns,
+				SQLiteAxolotlStore.ACCOUNT + " = ? AND "
+						+ SQLiteAxolotlStore.NAME + " = ? AND "
+						+ SQLiteAxolotlStore.DEVICE_ID + " = ? ",
+				selectionArgs,
+				null, null, null);
+
+		return cursor;
+	}
+
+	public SessionRecord loadSession(Account account, AxolotlAddress contact) {
+		SessionRecord session = null;
+		Cursor cursor = getCursorForSession(account, contact);
+		if (cursor.getCount() != 0) {
+			cursor.moveToFirst();
+			try {
+				session = new SessionRecord(Base64.decode(cursor.getString(cursor.getColumnIndex(SQLiteAxolotlStore.KEY)), Base64.DEFAULT));
+			} catch (IOException e) {
+				cursor.close();
+				throw new AssertionError(e);
+			}
+		}
 		cursor.close();
-		return conversation;
+		return session;
+	}
+
+	public List<Integer> getSubDeviceSessions(Account account, AxolotlAddress contact) {
+		final SQLiteDatabase db = this.getReadableDatabase();
+		return getSubDeviceSessions(db, account, contact);
 	}
 
-	public Message findMessageByUuid(String messageUuid) {
+	private List<Integer> getSubDeviceSessions(SQLiteDatabase db, Account account, AxolotlAddress contact) {
+		List<Integer> devices = new ArrayList<>();
+		String[] columns = {SQLiteAxolotlStore.DEVICE_ID};
+		String[] selectionArgs = {account.getUuid(),
+				contact.getName()};
+		Cursor cursor = db.query(SQLiteAxolotlStore.SESSION_TABLENAME,
+				columns,
+				SQLiteAxolotlStore.ACCOUNT + " = ? AND "
+						+ SQLiteAxolotlStore.NAME + " = ?",
+				selectionArgs,
+				null, null, null);
+
+		while (cursor.moveToNext()) {
+			devices.add(cursor.getInt(
+					cursor.getColumnIndex(SQLiteAxolotlStore.DEVICE_ID)));
+		}
+
+		cursor.close();
+		return devices;
+	}
+
+	public boolean containsSession(Account account, AxolotlAddress contact) {
+		Cursor cursor = getCursorForSession(account, contact);
+		int count = cursor.getCount();
+		cursor.close();
+		return count != 0;
+	}
+
+	public void storeSession(Account account, AxolotlAddress contact, SessionRecord session) {
+		SQLiteDatabase db = this.getWritableDatabase();
+		ContentValues values = new ContentValues();
+		values.put(SQLiteAxolotlStore.NAME, contact.getName());
+		values.put(SQLiteAxolotlStore.DEVICE_ID, contact.getDeviceId());
+		values.put(SQLiteAxolotlStore.KEY, Base64.encodeToString(session.serialize(), Base64.DEFAULT));
+		values.put(SQLiteAxolotlStore.ACCOUNT, account.getUuid());
+		db.insert(SQLiteAxolotlStore.SESSION_TABLENAME, null, values);
+	}
+
+	public void deleteSession(Account account, AxolotlAddress contact) {
+		SQLiteDatabase db = this.getWritableDatabase();
+		deleteSession(db, account, contact);
+	}
+
+	private void deleteSession(SQLiteDatabase db, Account account, AxolotlAddress contact) {
+		String[] args = {account.getUuid(),
+				contact.getName(),
+				Integer.toString(contact.getDeviceId())};
+		db.delete(SQLiteAxolotlStore.SESSION_TABLENAME,
+				SQLiteAxolotlStore.ACCOUNT + " = ? AND "
+						+ SQLiteAxolotlStore.NAME + " = ? AND "
+						+ SQLiteAxolotlStore.DEVICE_ID + " = ? ",
+				args);
+	}
+
+	public void deleteAllSessions(Account account, AxolotlAddress contact) {
+		SQLiteDatabase db = this.getWritableDatabase();
+		String[] args = {account.getUuid(), contact.getName()};
+		db.delete(SQLiteAxolotlStore.SESSION_TABLENAME,
+				SQLiteAxolotlStore.ACCOUNT + "=? AND "
+						+ SQLiteAxolotlStore.NAME + " = ?",
+				args);
+	}
+
+	private Cursor getCursorForPreKey(Account account, int preKeyId) {
 		SQLiteDatabase db = this.getReadableDatabase();
-		String[] selectionArgs = { messageUuid };
-		Cursor cursor = db.query(Message.TABLENAME, null, Message.UUID + "=?",
-				selectionArgs, null, null, null);
-		if (cursor.getCount() == 0) {
-			return null;
+		String[] columns = {SQLiteAxolotlStore.KEY};
+		String[] selectionArgs = {account.getUuid(), Integer.toString(preKeyId)};
+		Cursor cursor = db.query(SQLiteAxolotlStore.PREKEY_TABLENAME,
+				columns,
+				SQLiteAxolotlStore.ACCOUNT + "=? AND "
+						+ SQLiteAxolotlStore.ID + "=?",
+				selectionArgs,
+				null, null, null);
+
+		return cursor;
+	}
+
+	public PreKeyRecord loadPreKey(Account account, int preKeyId) {
+		PreKeyRecord record = null;
+		Cursor cursor = getCursorForPreKey(account, preKeyId);
+		if (cursor.getCount() != 0) {
+			cursor.moveToFirst();
+			try {
+				record = new PreKeyRecord(Base64.decode(cursor.getString(cursor.getColumnIndex(SQLiteAxolotlStore.KEY)), Base64.DEFAULT));
+			} catch (IOException e) {
+				throw new AssertionError(e);
+			}
 		}
-		cursor.moveToFirst();
-		Message message = Message.fromCursor(cursor);
 		cursor.close();
-		return message;
+		return record;
 	}
 
-	public Account findAccountByUuid(String accountUuid) {
+	public boolean containsPreKey(Account account, int preKeyId) {
+		Cursor cursor = getCursorForPreKey(account, preKeyId);
+		int count = cursor.getCount();
+		cursor.close();
+		return count != 0;
+	}
+
+	public void storePreKey(Account account, PreKeyRecord record) {
+		SQLiteDatabase db = this.getWritableDatabase();
+		ContentValues values = new ContentValues();
+		values.put(SQLiteAxolotlStore.ID, record.getId());
+		values.put(SQLiteAxolotlStore.KEY, Base64.encodeToString(record.serialize(), Base64.DEFAULT));
+		values.put(SQLiteAxolotlStore.ACCOUNT, account.getUuid());
+		db.insert(SQLiteAxolotlStore.PREKEY_TABLENAME, null, values);
+	}
+
+	public void deletePreKey(Account account, int preKeyId) {
+		SQLiteDatabase db = this.getWritableDatabase();
+		String[] args = {account.getUuid(), Integer.toString(preKeyId)};
+		db.delete(SQLiteAxolotlStore.PREKEY_TABLENAME,
+				SQLiteAxolotlStore.ACCOUNT + "=? AND "
+						+ SQLiteAxolotlStore.ID + "=?",
+				args);
+	}
+
+	private Cursor getCursorForSignedPreKey(Account account, int signedPreKeyId) {
 		SQLiteDatabase db = this.getReadableDatabase();
-		String[] selectionArgs = { accountUuid };
-		Cursor cursor = db.query(Account.TABLENAME, null, Account.UUID + "=?",
-				selectionArgs, null, null, null);
-		if (cursor.getCount() == 0) {
-			return null;
+		String[] columns = {SQLiteAxolotlStore.KEY};
+		String[] selectionArgs = {account.getUuid(), Integer.toString(signedPreKeyId)};
+		Cursor cursor = db.query(SQLiteAxolotlStore.SIGNED_PREKEY_TABLENAME,
+				columns,
+				SQLiteAxolotlStore.ACCOUNT + "=? AND " + SQLiteAxolotlStore.ID + "=?",
+				selectionArgs,
+				null, null, null);
+
+		return cursor;
+	}
+
+	public SignedPreKeyRecord loadSignedPreKey(Account account, int signedPreKeyId) {
+		SignedPreKeyRecord record = null;
+		Cursor cursor = getCursorForSignedPreKey(account, signedPreKeyId);
+		if (cursor.getCount() != 0) {
+			cursor.moveToFirst();
+			try {
+				record = new SignedPreKeyRecord(Base64.decode(cursor.getString(cursor.getColumnIndex(SQLiteAxolotlStore.KEY)), Base64.DEFAULT));
+			} catch (IOException e) {
+				throw new AssertionError(e);
+			}
 		}
-		cursor.moveToFirst();
-		Account account = Account.fromCursor(cursor);
 		cursor.close();
-		return account;
+		return record;
 	}
 
-	public List<Message> getImageMessages(Conversation conversation) {
-		ArrayList<Message> list = new ArrayList<>();
+	public List<SignedPreKeyRecord> loadSignedPreKeys(Account account) {
+		List<SignedPreKeyRecord> prekeys = new ArrayList<>();
 		SQLiteDatabase db = this.getReadableDatabase();
-		Cursor cursor;
-			String[] selectionArgs = { conversation.getUuid(), String.valueOf(Message.TYPE_IMAGE) };
-			cursor = db.query(Message.TABLENAME, null, Message.CONVERSATION
-					+ "=? AND "+Message.TYPE+"=?", selectionArgs, null, null,null);
+		String[] columns = {SQLiteAxolotlStore.KEY};
+		String[] selectionArgs = {account.getUuid()};
+		Cursor cursor = db.query(SQLiteAxolotlStore.SIGNED_PREKEY_TABLENAME,
+				columns,
+				SQLiteAxolotlStore.ACCOUNT + "=?",
+				selectionArgs,
+				null, null, null);
+
+		while (cursor.moveToNext()) {
+			try {
+				prekeys.add(new SignedPreKeyRecord(Base64.decode(cursor.getString(cursor.getColumnIndex(SQLiteAxolotlStore.KEY)), Base64.DEFAULT)));
+			} catch (IOException ignored) {
+			}
+		}
+		cursor.close();
+		return prekeys;
+	}
+
+	public boolean containsSignedPreKey(Account account, int signedPreKeyId) {
+		Cursor cursor = getCursorForPreKey(account, signedPreKeyId);
+		int count = cursor.getCount();
+		cursor.close();
+		return count != 0;
+	}
+
+	public void storeSignedPreKey(Account account, SignedPreKeyRecord record) {
+		SQLiteDatabase db = this.getWritableDatabase();
+		ContentValues values = new ContentValues();
+		values.put(SQLiteAxolotlStore.ID, record.getId());
+		values.put(SQLiteAxolotlStore.KEY, Base64.encodeToString(record.serialize(), Base64.DEFAULT));
+		values.put(SQLiteAxolotlStore.ACCOUNT, account.getUuid());
+		db.insert(SQLiteAxolotlStore.SIGNED_PREKEY_TABLENAME, null, values);
+	}
+
+	public void deleteSignedPreKey(Account account, int signedPreKeyId) {
+		SQLiteDatabase db = this.getWritableDatabase();
+		String[] args = {account.getUuid(), Integer.toString(signedPreKeyId)};
+		db.delete(SQLiteAxolotlStore.SIGNED_PREKEY_TABLENAME,
+				SQLiteAxolotlStore.ACCOUNT + "=? AND "
+						+ SQLiteAxolotlStore.ID + "=?",
+				args);
+	}
+
+	private Cursor getIdentityKeyCursor(Account account, String name, boolean own) {
+		final SQLiteDatabase db = this.getReadableDatabase();
+		return getIdentityKeyCursor(db, account, name, own);
+	}
+
+	private Cursor getIdentityKeyCursor(SQLiteDatabase db, Account account, String name, boolean own) {
+		return getIdentityKeyCursor(db, account, name, own, null);
+	}
+
+	private Cursor getIdentityKeyCursor(Account account, String fingerprint) {
+		final SQLiteDatabase db = this.getReadableDatabase();
+		return getIdentityKeyCursor(db, account, fingerprint);
+	}
+
+	private Cursor getIdentityKeyCursor(SQLiteDatabase db, Account account, String fingerprint) {
+		return getIdentityKeyCursor(db, account, null, null, fingerprint);
+	}
+
+	private Cursor getIdentityKeyCursor(SQLiteDatabase db, Account account, String name, Boolean own, String fingerprint) {
+		String[] columns = {SQLiteAxolotlStore.TRUSTED,
+				SQLiteAxolotlStore.KEY};
+		ArrayList<String> selectionArgs = new ArrayList<>(4);
+		selectionArgs.add(account.getUuid());
+		String selectionString = SQLiteAxolotlStore.ACCOUNT + " = ?";
+		if (name != null) {
+			selectionArgs.add(name);
+			selectionString += " AND " + SQLiteAxolotlStore.NAME + " = ?";
+		}
+		if (fingerprint != null) {
+			selectionArgs.add(fingerprint);
+			selectionString += " AND " + SQLiteAxolotlStore.FINGERPRINT + " = ?";
+		}
+		if (own != null) {
+			selectionArgs.add(own ? "1" : "0");
+			selectionString += " AND " + SQLiteAxolotlStore.OWN + " = ?";
+		}
+		Cursor cursor = db.query(SQLiteAxolotlStore.IDENTITIES_TABLENAME,
+				columns,
+				selectionString,
+				selectionArgs.toArray(new String[selectionArgs.size()]),
+				null, null, null);
+
+		return cursor;
+	}
+
+	public IdentityKeyPair loadOwnIdentityKeyPair(Account account) {
+		SQLiteDatabase db = getReadableDatabase();
+		return loadOwnIdentityKeyPair(db, account);
+	}
+
+	private IdentityKeyPair loadOwnIdentityKeyPair(SQLiteDatabase db, Account account) {
+		String name = account.getJid().toBareJid().toString();
+		IdentityKeyPair identityKeyPair = null;
+		Cursor cursor = getIdentityKeyCursor(db, account, name, true);
+		if (cursor.getCount() != 0) {
+			cursor.moveToFirst();
+			try {
+				identityKeyPair = new IdentityKeyPair(Base64.decode(cursor.getString(cursor.getColumnIndex(SQLiteAxolotlStore.KEY)), Base64.DEFAULT));
+			} catch (InvalidKeyException e) {
+				Log.d(Config.LOGTAG, AxolotlServiceImpl.getLogprefix(account) + "Encountered invalid IdentityKey in database for account" + account.getJid().toBareJid() + ", address: " + name);
+			}
+		}
+		cursor.close();
+
+		return identityKeyPair;
+	}
+
+	public Set<IdentityKey> loadIdentityKeys(Account account, String name) {
+		return loadIdentityKeys(account, name, null);
+	}
+
+	public Set<IdentityKey> loadIdentityKeys(Account account, String name, XmppAxolotlSession.Trust trust) {
+		Set<IdentityKey> identityKeys = new HashSet<>();
+		Cursor cursor = getIdentityKeyCursor(account, name, false);
+
+		while (cursor.moveToNext()) {
+			if (trust != null &&
+					cursor.getInt(cursor.getColumnIndex(SQLiteAxolotlStore.TRUSTED))
+							!= trust.getCode()) {
+				continue;
+			}
+			try {
+				identityKeys.add(new IdentityKey(Base64.decode(cursor.getString(cursor.getColumnIndex(SQLiteAxolotlStore.KEY)), Base64.DEFAULT), 0));
+			} catch (InvalidKeyException e) {
+				Log.d(Config.LOGTAG, AxolotlServiceImpl.getLogprefix(account) + "Encountered invalid IdentityKey in database for account" + account.getJid().toBareJid() + ", address: " + name);
+			}
+		}
+		cursor.close();
+
+		return identityKeys;
+	}
+
+	public long numTrustedKeys(Account account, String name) {
+		SQLiteDatabase db = getReadableDatabase();
+		String[] args = {
+				account.getUuid(),
+				name,
+				String.valueOf(XmppAxolotlSession.Trust.TRUSTED.getCode()),
+				String.valueOf(XmppAxolotlSession.Trust.TRUSTED_X509.getCode())
+		};
+		return DatabaseUtils.queryNumEntries(db, SQLiteAxolotlStore.IDENTITIES_TABLENAME,
+				SQLiteAxolotlStore.ACCOUNT + " = ?"
+						+ " AND " + SQLiteAxolotlStore.NAME + " = ?"
+						+ " AND (" + SQLiteAxolotlStore.TRUSTED + " = ? OR " + SQLiteAxolotlStore.TRUSTED + " = ?)",
+				args
+		);
+	}
+
+	private void storeIdentityKey(Account account, String name, boolean own, String fingerprint, String base64Serialized) {
+		storeIdentityKey(account, name, own, fingerprint, base64Serialized, XmppAxolotlSession.Trust.UNDECIDED);
+	}
+
+	private void storeIdentityKey(Account account, String name, boolean own, String fingerprint, String base64Serialized, XmppAxolotlSession.Trust trusted) {
+		SQLiteDatabase db = this.getWritableDatabase();
+		ContentValues values = new ContentValues();
+		values.put(SQLiteAxolotlStore.ACCOUNT, account.getUuid());
+		values.put(SQLiteAxolotlStore.NAME, name);
+		values.put(SQLiteAxolotlStore.OWN, own ? 1 : 0);
+		values.put(SQLiteAxolotlStore.FINGERPRINT, fingerprint);
+		values.put(SQLiteAxolotlStore.KEY, base64Serialized);
+		values.put(SQLiteAxolotlStore.TRUSTED, trusted.getCode());
+		db.insert(SQLiteAxolotlStore.IDENTITIES_TABLENAME, null, values);
+	}
+
+	public XmppAxolotlSession.Trust isIdentityKeyTrusted(Account account, String fingerprint) {
+		Cursor cursor = getIdentityKeyCursor(account, fingerprint);
+		XmppAxolotlSession.Trust trust = null;
 		if (cursor.getCount() > 0) {
-			cursor.moveToLast();
-			do {
-				Message message = Message.fromCursor(cursor);
-				message.setConversation(conversation);
-				list.add(message);
-			} while (cursor.moveToPrevious());
+			cursor.moveToFirst();
+			int trustValue = cursor.getInt(cursor.getColumnIndex(SQLiteAxolotlStore.TRUSTED));
+			trust = XmppAxolotlSession.Trust.fromCode(trustValue);
 		}
 		cursor.close();
-		return list;
+		return trust;
+	}
+
+	public boolean setIdentityKeyTrust(Account account, String fingerprint, XmppAxolotlSession.Trust trust) {
+		SQLiteDatabase db = this.getWritableDatabase();
+		return setIdentityKeyTrust(db, account, fingerprint, trust);
+	}
+
+	private boolean setIdentityKeyTrust(SQLiteDatabase db, Account account, String fingerprint, XmppAxolotlSession.Trust trust) {
+		String[] selectionArgs = {
+				account.getUuid(),
+				fingerprint
+		};
+		ContentValues values = new ContentValues();
+		values.put(SQLiteAxolotlStore.TRUSTED, trust.getCode());
+		int rows = db.update(SQLiteAxolotlStore.IDENTITIES_TABLENAME, values,
+				SQLiteAxolotlStore.ACCOUNT + " = ? AND "
+						+ SQLiteAxolotlStore.FINGERPRINT + " = ? ",
+				selectionArgs);
+		return rows == 1;
+	}
+
+	public boolean setIdentityKeyCertificate(Account account, String fingerprint, X509Certificate x509Certificate) {
+		SQLiteDatabase db = this.getWritableDatabase();
+		String[] selectionArgs = {
+				account.getUuid(),
+				fingerprint
+		};
+		try {
+			ContentValues values = new ContentValues();
+			values.put(SQLiteAxolotlStore.CERTIFICATE, x509Certificate.getEncoded());
+			return db.update(SQLiteAxolotlStore.IDENTITIES_TABLENAME, values,
+					SQLiteAxolotlStore.ACCOUNT + " = ? AND "
+							+ SQLiteAxolotlStore.FINGERPRINT + " = ? ",
+					selectionArgs) == 1;
+		} catch (CertificateEncodingException e) {
+			Log.d(Config.LOGTAG, "could not encode certificate");
+			return false;
+		}
+	}
+
+	public X509Certificate getIdentityKeyCertifcate(Account account, String fingerprint) {
+		SQLiteDatabase db = this.getReadableDatabase();
+		String[] selectionArgs = {
+				account.getUuid(),
+				fingerprint
+		};
+		String[] colums = {SQLiteAxolotlStore.CERTIFICATE};
+		String selection = SQLiteAxolotlStore.ACCOUNT + " = ? AND " + SQLiteAxolotlStore.FINGERPRINT + " = ? ";
+		Cursor cursor = db.query(SQLiteAxolotlStore.IDENTITIES_TABLENAME, colums, selection, selectionArgs, null, null, null);
+		if (cursor.getCount() < 1) {
+			return null;
+		} else {
+			cursor.moveToFirst();
+			byte[] certificate = cursor.getBlob(cursor.getColumnIndex(SQLiteAxolotlStore.CERTIFICATE));
+			if (certificate == null || certificate.length == 0) {
+				return null;
+			}
+			try {
+				CertificateFactory certificateFactory = CertificateFactory.getInstance("X.509");
+				return (X509Certificate) certificateFactory.generateCertificate(new ByteArrayInputStream(certificate));
+			} catch (CertificateException e) {
+				Log.d(Config.LOGTAG,"certificate exception "+e.getMessage());
+				return null;
+			}
+		}
+	}
+
+	public void storeIdentityKey(Account account, String name, IdentityKey identityKey) {
+		storeIdentityKey(account, name, false, identityKey.getFingerprint().replaceAll("\\s", ""), Base64.encodeToString(identityKey.serialize(), Base64.DEFAULT));
+	}
+
+	public void storeOwnIdentityKeyPair(Account account, IdentityKeyPair identityKeyPair) {
+		storeIdentityKey(account, account.getJid().toBareJid().toString(), true, identityKeyPair.getPublicKey().getFingerprint().replaceAll("\\s", ""), Base64.encodeToString(identityKeyPair.serialize(), Base64.DEFAULT), XmppAxolotlSession.Trust.TRUSTED);
+	}
+
+	public void recreateAxolotlDb() {
+		recreateAxolotlDb(getWritableDatabase());
+	}
+
+	public void recreateAxolotlDb(SQLiteDatabase db) {
+		Log.d(Config.LOGTAG, AxolotlServiceImpl.LOGPREFIX + " : " + ">>> (RE)CREATING AXOLOTL DATABASE <<<");
+		db.execSQL("DROP TABLE IF EXISTS " + SQLiteAxolotlStore.SESSION_TABLENAME);
+		db.execSQL(CREATE_SESSIONS_STATEMENT);
+		db.execSQL("DROP TABLE IF EXISTS " + SQLiteAxolotlStore.PREKEY_TABLENAME);
+		db.execSQL(CREATE_PREKEYS_STATEMENT);
+		db.execSQL("DROP TABLE IF EXISTS " + SQLiteAxolotlStore.SIGNED_PREKEY_TABLENAME);
+		db.execSQL(CREATE_SIGNED_PREKEYS_STATEMENT);
+		db.execSQL("DROP TABLE IF EXISTS " + SQLiteAxolotlStore.IDENTITIES_TABLENAME);
+		db.execSQL(CREATE_IDENTITIES_STATEMENT);
+	}
+
+	public void wipeAxolotlDb(Account account) {
+		String accountName = account.getUuid();
+		Log.d(Config.LOGTAG, AxolotlServiceImpl.getLogprefix(account) + ">>> WIPING AXOLOTL DATABASE FOR ACCOUNT " + accountName + " <<<");
+		SQLiteDatabase db = this.getWritableDatabase();
+		String[] deleteArgs = {
+				accountName
+		};
+		db.delete(SQLiteAxolotlStore.SESSION_TABLENAME,
+				SQLiteAxolotlStore.ACCOUNT + " = ?",
+				deleteArgs);
+		db.delete(SQLiteAxolotlStore.PREKEY_TABLENAME,
+				SQLiteAxolotlStore.ACCOUNT + " = ?",
+				deleteArgs);
+		db.delete(SQLiteAxolotlStore.SIGNED_PREKEY_TABLENAME,
+				SQLiteAxolotlStore.ACCOUNT + " = ?",
+				deleteArgs);
+		db.delete(SQLiteAxolotlStore.IDENTITIES_TABLENAME,
+				SQLiteAxolotlStore.ACCOUNT + " = ?",
+				deleteArgs);
 	}
 }
diff --git a/src/main/java/de/thedevstack/conversationsplus/persistance/FileBackend.java b/src/main/java/de/thedevstack/conversationsplus/persistance/FileBackend.java
index d58d0583..611f573c 100644
--- a/src/main/java/de/thedevstack/conversationsplus/persistance/FileBackend.java
+++ b/src/main/java/de/thedevstack/conversationsplus/persistance/FileBackend.java
@@ -1,38 +1,32 @@
 package de.thedevstack.conversationsplus.persistance;
 
+import android.graphics.Bitmap;
+import android.net.Uri;
+import android.os.Environment;
+import android.util.Log;
+import android.webkit.MimeTypeMap;
+
 import java.io.File;
 import java.io.FileNotFoundException;
 import java.io.FileOutputStream;
 import java.io.IOException;
 import java.io.InputStream;
 import java.io.OutputStream;
-import java.net.URL;
 import java.text.SimpleDateFormat;
-import java.util.Arrays;
 import java.util.Date;
 import java.util.Locale;
 
-import android.graphics.Bitmap;
-import android.graphics.BitmapFactory;
-import android.net.Uri;
-import android.os.Environment;
-import android.webkit.MimeTypeMap;
-
 import de.thedevstack.android.logcat.Logging;
-import de.thedevstack.conversationsplus.Config;
 import de.thedevstack.conversationsplus.ConversationsPlusApplication;
 import de.thedevstack.conversationsplus.ConversationsPlusPreferences;
+import de.thedevstack.conversationsplus.exceptions.FileCopyException;
+import de.thedevstack.conversationsplus.utils.StreamUtil;
+import de.thedevstack.conversationsplus.Config;
 import de.thedevstack.conversationsplus.R;
-import de.thedevstack.conversationsplus.entities.Transferable;
 import de.thedevstack.conversationsplus.entities.DownloadableFile;
 import de.thedevstack.conversationsplus.entities.Message;
-import de.thedevstack.conversationsplus.exceptions.FileCopyException;
-import de.thedevstack.conversationsplus.utils.ImageUtil;
-import de.thedevstack.conversationsplus.utils.MessageUtil;
-import de.thedevstack.conversationsplus.utils.StreamUtil;
-
-public final class FileBackend {
 
+public class FileBackend {
 	private static final SimpleDateFormat imageDateFormat = new SimpleDateFormat("yyyyMMdd_HHmmssSSS", Locale.US);
 
 	public static DownloadableFile getFile(Message message) {
@@ -40,34 +34,28 @@ public final class FileBackend {
 	}
 
 	public static DownloadableFile getFile(Message message, boolean decrypted) {
+		final boolean encrypted = !decrypted
+				&& (message.getEncryption() == Message.ENCRYPTION_PGP
+				|| message.getEncryption() == Message.ENCRYPTION_DECRYPTED);
+		final DownloadableFile file;
 		String path = message.getRelativeFilePath();
-		String extension;
-		if (path != null && !path.isEmpty()) {
-			String[] parts = path.split("\\.");
-			extension = "."+parts[parts.length - 1];
+		if (path == null) {
+			path = message.getUuid();
+		}
+		if (path.startsWith("/")) {
+			file = new DownloadableFile(path);
 		} else {
-			if (message.getType() == Message.TYPE_IMAGE || message.getType() == Message.TYPE_TEXT) {
-				extension = ".png";
+			String mime = message.getMimeType();
+			if (mime != null && mime.startsWith("image")) {
+				file = new DownloadableFile(getConversationsImageDirectory() + path);
 			} else {
-				extension = "";
+				file = new DownloadableFile(getConversationsFileDirectory() + path);
 			}
-			path = message.getUuid()+extension;
 		}
-		final boolean encrypted = !decrypted
-				&& (message.getEncryption() == Message.ENCRYPTION_PGP
-				|| message.getEncryption() == Message.ENCRYPTION_DECRYPTED);
 		if (encrypted) {
-			return new DownloadableFile(getConversationsFileDirectory()+message.getUuid()+extension+".pgp");
+			return new DownloadableFile(getConversationsFileDirectory() + file.getName() + ".pgp");
 		} else {
-			if (path.startsWith("/")) {
-				return new DownloadableFile(path);
-			} else {
-				if (Arrays.asList(Transferable.VALID_IMAGE_EXTENSIONS).contains(extension)) {
-					return new DownloadableFile(getConversationsImageDirectory() + path);
-				} else {
-					return new DownloadableFile(getConversationsFileDirectory() + path);
-				}
-			}
+			return file;
 		}
 	}
 
@@ -87,12 +75,7 @@ public final class FileBackend {
         return FileBackend.getPrivateFileDirectoryPath() + File.separator + "Images" + File.separator;
     }
 
-	public static DownloadableFile copyFileToPrivateStorage(Message message, Uri uri) throws FileCopyException {
-		Logging.d(Config.LOGTAG, "copy " + uri.toString() + " to private storage");
-		String mime = ConversationsPlusApplication.getInstance().getContentResolver().getType(uri);
-		String extension = MimeTypeMap.getSingleton().getExtensionFromMimeType(mime);
-		message.setRelativeFilePath(FileBackend.getPrivateFileDirectoryPath() + message.getUuid() + "." + extension);
-		DownloadableFile file = getFile(message);
+	public static void copyFileToPrivateStorage(File file, Uri uri) throws FileCopyException {
 		file.getParentFile().mkdirs();
 		OutputStream os = null;
 		InputStream is = null;
@@ -116,36 +99,43 @@ public final class FileBackend {
 			StreamUtil.close(is);
 		}
 		Logging.d(Config.LOGTAG, "output file name " + file);
-		return file;
 	}
 
-	public static DownloadableFile compressImageAndCopyToPrivateStorage(Message message, Bitmap scaledBitmap) throws FileCopyException {
+	public static void copyFileToPrivateStorage(Message message, Uri uri) throws FileCopyException {
+		Log.d(Config.LOGTAG, "copy " + uri.toString() + " to private storage");
+		String mime = ConversationsPlusApplication.getInstance().getContentResolver().getType(uri);
+		String extension = MimeTypeMap.getSingleton().getExtensionFromMimeType(mime);
+		message.setRelativeFilePath(message.getUuid() + "." + extension);
+		copyFileToPrivateStorage(getFile(message), uri);
+	}
+
+    public static DownloadableFile compressImageAndCopyToPrivateStorage(Message message, Bitmap scaledBitmap) throws FileCopyException {
         message.setRelativeFilePath(FileBackend.getPrivateImageDirectoryPath() + message.getUuid() + ".png");
-		DownloadableFile file = getFile(message);
-		file.getParentFile().mkdirs();
-		OutputStream os = null;
-		try {
-			file.createNewFile();
+        DownloadableFile file = getFile(message);
+        file.getParentFile().mkdirs();
+        OutputStream os = null;
+        try {
+            file.createNewFile();
             os = new FileOutputStream(file);
 
-			boolean success = scaledBitmap.compress(Bitmap.CompressFormat.PNG, 75, os);
-			if (!success) {
-				throw new FileCopyException(R.string.error_compressing_image);
-			}
-			os.flush();
+            boolean success = scaledBitmap.compress(Bitmap.CompressFormat.PNG, 75, os);
+            if (!success) {
+                throw new FileCopyException(R.string.error_compressing_image);
+            }
+            os.flush();
         } catch (IOException e) {
             throw new FileCopyException(R.string.error_io_exception, e);
-		} catch (SecurityException e) {
+        } catch (SecurityException e) {
             throw new FileCopyException(R.string.error_security_exception_during_image_copy);
         } catch (NullPointerException e) {
-			throw new FileCopyException(R.string.error_io_exception);
-		} finally {
-			StreamUtil.close(os);
-		}
+            throw new FileCopyException(R.string.error_io_exception);
+        } finally {
+            StreamUtil.close(os);
+        }
         return file;
-	}
+    }
 
-    public static Uri getTakePhotoUri() {
+	public static Uri getTakePhotoUri() {
 		StringBuilder pathBuilder = new StringBuilder();
 		pathBuilder.append(Environment.getExternalStoragePublicDirectory(Environment.DIRECTORY_DCIM));
 		pathBuilder.append('/');
@@ -170,4 +160,4 @@ public final class FileBackend {
     private FileBackend() {
         // Static helper class
     }
-}
\ No newline at end of file
+}