Bump version to 2.8.1

With the introduction of UUIDs, we need to be able to generate
fingerprints from raw bytes, not just strings. In addition, we need to
be able to conditionally set the fingerprint version based on whether or
not we're using UUIDs.

LICENSE

@@ -0,0 +1,674 @@
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+
+  16. Limitation of Liability.
+
+  IN NO EVENT UNLESS REQUIRED BY APPLICABLE LAW OR AGREED TO IN WRITING
+WILL ANY COPYRIGHT HOLDER, OR ANY OTHER PARTY WHO MODIFIES AND/OR CONVEYS
+THE PROGRAM AS PERMITTED ABOVE, BE LIABLE TO YOU FOR DAMAGES, INCLUDING ANY
+GENERAL, SPECIAL, INCIDENTAL OR CONSEQUENTIAL DAMAGES ARISING OUT OF THE
+USE OR INABILITY TO USE THE PROGRAM (INCLUDING BUT NOT LIMITED TO LOSS OF
+DATA OR DATA BEING RENDERED INACCURATE OR LOSSES SUSTAINED BY YOU OR THIRD
+PARTIES OR A FAILURE OF THE PROGRAM TO OPERATE WITH ANY OTHER PROGRAMS),
+EVEN IF SUCH HOLDER OR OTHER PARTY HAS BEEN ADVISED OF THE POSSIBILITY OF
+SUCH DAMAGES.
+
+  17. Interpretation of Sections 15 and 16.
+
+  If the disclaimer of warranty and limitation of liability provided
+above cannot be given local legal effect according to their terms,
+reviewing courts shall apply local law that most closely approximates
+an absolute waiver of all civil liability in connection with the
+Program, unless a warranty or assumption of liability accompanies a
+copy of the Program in return for a fee.
+
+                     END OF TERMS AND CONDITIONS
+
+            How to Apply These Terms to Your New Programs
+
+  If you develop a new program, and you want it to be of the greatest
+possible use to the public, the best way to achieve this is to make it
+free software which everyone can redistribute and change under these terms.
+
+  To do so, attach the following notices to the program.  It is safest
+to attach them to the start of each source file to most effectively
+state the exclusion of warranty; and each file should have at least
+the "copyright" line and a pointer to where the full notice is found.
+
+    <one line to give the program's name and a brief idea of what it does.>
+    Copyright (C) <year>  <name of author>
+
+    This program is free software: you can redistribute it and/or modify
+    it under the terms of the GNU General Public License as published by
+    the Free Software Foundation, either version 3 of the License, or
+    (at your option) any later version.
+
+    This program is distributed in the hope that it will be useful,
+    but WITHOUT ANY WARRANTY; without even the implied warranty of
+    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+    GNU General Public License for more details.
+
+    You should have received a copy of the GNU General Public License
+    along with this program.  If not, see <http://www.gnu.org/licenses/>.
+
+Also add information on how to contact you by electronic and paper mail.
+
+  If the program does terminal interaction, make it output a short
+notice like this when it starts in an interactive mode:
+
+    <program>  Copyright (C) <year>  <name of author>
+    This program comes with ABSOLUTELY NO WARRANTY; for details type `show w'.
+    This is free software, and you are welcome to redistribute it
+    under certain conditions; type `show c' for details.
+
+The hypothetical commands `show w' and `show c' should show the appropriate
+parts of the General Public License.  Of course, your program's commands
+might be different; for a GUI interface, you would use an "about box".
+
+  You should also get your employer (if you work as a programmer) or school,
+if any, to sign a "copyright disclaimer" for the program, if necessary.
+For more information on this, and how to apply and follow the GNU GPL, see
+<http://www.gnu.org/licenses/>.
+
+  The GNU General Public License does not permit incorporating your program
+into proprietary programs.  If your program is a subroutine library, you
+may consider it more useful to permit linking proprietary applications with
+the library.  If this is what you want to do, use the GNU Lesser General
+Public License instead of this License.  But first, please read
+<http://www.gnu.org/philosophy/why-not-lgpl.html>.

README.md

@@ -1,9 +1,6 @@
-
 # Overview
 
-This is a ratcheting forward secrecy protocol that works in synchronous and asynchronous messaging 
-environments.  The protocol overview is available [here](https://github.com/trevp/axolotl/wiki),
-and the details of the wire format are available [here](https://github.com/WhisperSystems/TextSecure/wiki/ProtocolV2).
+A ratcheting forward secrecy protocol that works in synchronous and asynchronous messaging environments.
 
 ## PreKeys
 
@@ -15,7 +12,7 @@ PreKeys, and transmit all of them to the server.
 
 ## Sessions
 
-The axolotl protocol is session-oriented.  Clients establish a "session," which is then used for
+Signal Protocol is session-oriented.  Clients establish a "session," which is then used for
 all subsequent encrypt/decrypt operations.  There is no need to ever tear down a session once one
 has been established.
 
@@ -23,7 +20,7 @@ Sessions are established in one of three ways:
 
 1. PreKeyBundles. A client that wishes to send a message to a recipient can establish a session by
    retrieving a PreKeyBundle for that recipient from the server.
-1. PreKeyWhisperMessages.  A client can receive a PreKeyWhisperMessage from a recipient and use it
+1. PreKeySignalMessages.  A client can receive a PreKeySignalMessage from a recipient and use it
    to establish a session.
 1. KeyExchangeMessages.  Two clients can exchange KeyExchange messages to establish a session.
 
@@ -40,70 +37,73 @@ State is kept in the following places:
 1. Signed PreKey States. Clients will need to maintain the state of their signed PreKeys.
 1. Session State.  Clients will need to maintain the state of the sessions they have established.
 
-# Using libaxolotl
+# Using libsignal-protocol
 
 ## Configuration
 
 On Android:
 
-```
+```groovy
 dependencies {
-  compile 'org.whispersystems:axolotl-android:(latest version number)'
+  compile 'org.whispersystems:signal-protocol-android:(latest version number)'
 }
 ```
 
 For pure Java apps:
 
-```
+```xml
 <dependency>
   <groupId>org.whispersystems</groupId>
-  <artifactId>axolotl-java</artifactId>
+  <artifactId>signal-protocol-java</artifactId>
   <version>(latest version number)</version>
 </dependency>
 ```
 
 ## Install time
 
-At install time, a libaxolotl client needs to generate its identity keys, registration id, and
+At install time, a libsignal client needs to generate its identity keys, registration id, and
 prekeys.
 
-    IdentityKeyPair    identityKeyPair = KeyHelper.generateIdentityKeyPair();
-    int                registrationId  = KeyHelper.generateRegistrationId();
-    List<PreKeyRecord> preKeys         = KeyHelper.generatePreKeys(startId, 100);
-    PreKeyRecord       lastResortKey   = KeyHelper.generateLastResortKey();
-    SignedPreKeyRecord signedPreKey    = KeyHelper.generateSignedPreKey(identityKeyPair, 5);
+ ```java
+ IdentityKeyPair    identityKeyPair = KeyHelper.generateIdentityKeyPair();
+ int                registrationId  = KeyHelper.generateRegistrationId();
+ List<PreKeyRecord> preKeys         = KeyHelper.generatePreKeys(startId, 100);
+ SignedPreKeyRecord signedPreKey    = KeyHelper.generateSignedPreKey(identityKeyPair, 5);
 
-    // Store identityKeyPair somewhere durable and safe.
-    // Store registrationId somewhere durable and safe.
-
-    // Store preKeys in PreKeyStore.
-    // Store signed prekey in SignedPreKeyStore.
+ // Store identityKeyPair somewhere durable and safe.
+ // Store registrationId somewhere durable and safe.
 
+ // Store preKeys in PreKeyStore.
+ // Store signed prekey in SignedPreKeyStore.
+ ```
+    
 ## Building a session
 
-A libaxolotl client needs to implement four interfaces: IdentityKeyStore, PreKeyStore, 
+A libsignal client needs to implement four interfaces: IdentityKeyStore, PreKeyStore,
 SignedPreKeyStore, and SessionStore.  These will manage loading and storing of identity, 
 prekeys, signed prekeys, and session state.
 
 Once those are implemented, building a session is fairly straightforward:
 
-    SessionStore      sessionStore      = new MySessionStore();
-    PreKeyStore       preKeyStore       = new MyPreKeyStore();
-    SignedPreKeyStore signedPreKeyStore = new MySignedPreKeyStore();
-    IdentityKeyStore  identityStore     = new MyIdentityKeyStore();
+ ```java
+ SessionStore      sessionStore      = new MySessionStore();
+ PreKeyStore       preKeyStore       = new MyPreKeyStore();
+ SignedPreKeyStore signedPreKeyStore = new MySignedPreKeyStore();
+ IdentityKeyStore  identityStore     = new MyIdentityKeyStore();
 
-    // Instantiate a SessionBuilder for a remote recipientId + deviceId tuple.
-    SessionBuilder sessionBuilder = new SessionBuilder(sessionStore, preKeyStore, signedPreKeyStore,
-                                                       identityStore, recipientId, deviceId);
+ // Instantiate a SessionBuilder for a remote recipientId + deviceId tuple.
+ SessionBuilder sessionBuilder = new SessionBuilder(sessionStore, preKeyStore, signedPreKeyStore,
+                                                    identityStore, recipientId, deviceId);
 
-    // Build a session with a PreKey retrieved from the server.
-    sessionBuilder.process(retrievedPreKey);
+ // Build a session with a PreKey retrieved from the server.
+ sessionBuilder.process(retrievedPreKey);
 
-    SessionCipher     sessionCipher = new SessionCipher(sessionStore, recipientId, deviceId);
-    CiphertextMessage message      = sessionCipher.encrypt("Hello world!".getBytes("UTF-8"));
-
-    deliver(message.serialize());
+ SessionCipher     sessionCipher = new SessionCipher(sessionStore, recipientId, deviceId);
+ CiphertextMessage message      = sessionCipher.encrypt("Hello world!".getBytes("UTF-8"));
 
+ deliver(message.serialize());
+ ```
+    
 # Legal things
 ## Cryptography Notice
 
@@ -116,7 +116,7 @@ The form and manner of this distribution makes it eligible for export under the
 
 ## License
 
-Copyright 2013-2015 Open Whisper Systems
+Copyright 2013-2019 Open Whisper Systems
 
 Licensed under the GPLv3: http://www.gnu.org/licenses/gpl-3.0.html
 

android/build.gradle

@@ -1,10 +1,16 @@
 buildscript {
     repositories {
+        google()
         mavenCentral()
+        jcenter {
+            content {
+                includeVersion 'org.jetbrains.trove4j', 'trove4j', '20160824'
+            }
+        }
     }
 
     dependencies {
-        classpath 'com.android.tools.build:gradle:1.0.0'
+        classpath 'com.android.tools.build:gradle:3.5.1'
     }
 }
 
@@ -12,34 +18,40 @@ apply plugin: 'com.android.library'
 apply plugin: 'maven'
 apply plugin: 'signing'
 
-archivesBaseName = "axolotl-android"
+archivesBaseName = "signal-protocol-android"
 version          = version_number
 group            = group_info
 
 android {
-    compileSdkVersion 21
-    buildToolsVersion "21.1.2"
+    compileSdkVersion 28
+    buildToolsVersion '28.0.3'
+
+    defaultConfig {
+        minSdkVersion 19
+        targetSdkVersion 28
+    }
+
+    compileOptions {
+        sourceCompatibility JavaVersion.VERSION_1_7
+        targetCompatibility JavaVersion.VERSION_1_7
+    }
 
     sourceSets {
         androidTest {
             java.srcDirs = ['src/androidTest/java', project(':tests').file('src/test/java')]
         }
     }
-
-    libraryVariants.all { variant ->
-        variant.outputs.each { output ->
-            def outputFile = output.outputFile
-            if (outputFile != null && outputFile.name.endsWith('.aar')) {
-                def fileName = "${archivesBaseName}-${version}.aar"
-                output.outputFile = new File(outputFile.parent, fileName)
-            }
-        }
-    }
 }
 
 repositories {
+    google()
     mavenCentral()
     mavenLocal()
+    jcenter {
+        content {
+            includeVersion 'org.jetbrains.trove4j', 'trove4j', '20160824'
+        }
+    }
 }
 
 dependencies {
@@ -49,8 +61,25 @@ dependencies {
     }
 }
 
+def isReleaseBuild() {
+    return version.contains("SNAPSHOT") == false
+}
+
+def getReleaseRepositoryUrl() {
+    return hasProperty('sonatypeRepo') ? sonatypeRepo
+            : "https://oss.sonatype.org/service/local/staging/deploy/maven2/"
+}
+
+def getRepositoryUsername() {
+    return hasProperty('whisperSonatypeUsername') ? whisperSonatypeUsername : ""
+}
+
+def getRepositoryPassword() {
+    return hasProperty('whisperSonatypePassword') ? whisperSonatypePassword : ""
+}
+
 signing {
-    required { has("release") && gradle.taskGraph.hasTask("uploadArchives") }
+    required { isReleaseBuild() && gradle.taskGraph.hasTask("uploadArchives") }
     sign configurations.archives
 }
 
@@ -59,20 +88,20 @@ uploadArchives {
     repositories.mavenDeployer {
         beforeDeployment { MavenDeployment deployment -> signing.signPom(deployment) }
 
-        repository(url: sonatypeRepo) {
-            authentication(userName: whisperSonatypeUsername, password: whisperSonatypePassword)
+        repository(url: getReleaseRepositoryUrl()) {
+            authentication(userName: getRepositoryUsername(), password: getRepositoryPassword())
         }
 
         pom.project {
-            name 'axolotl-android'
+            name 'signal-protocol-android'
             packaging 'aar'
-            description 'Axolotl library for Android'
-            url 'https://github.com/WhisperSystems/libaxolotl-android'
+            description 'Signal Protocol cryptography library for Android'
+            url 'https://github.com/WhisperSystems/libsignal-android'
 
             scm {
-                url 'scm:git@github.com:WhisperSystems/libaxolotl-android.git'
-                connection 'scm:git@github.com:WhisperSystems/libaxolotl-android.git'
-                developerConnection 'scm:git@github.com:WhisperSystems/libaxolotl-android.git'
+                url 'scm:git@github.com:WhisperSystems/libsignal-android.git'
+                connection 'scm:git@github.com:WhisperSystems/libsignal-android.git'
+                developerConnection 'scm:git@github.com:WhisperSystems/libsignal-android.git'
             }
 
             licenses {

android/src/androidTest/java/org/whispersystems/libsignal/CurveTest.java

@@ -1,9 +1,9 @@
-package org.whispersystems.libaxolotl;
+package org.whispersystems.libsignal;
 
 import junit.framework.TestCase;
 
-import org.whispersystems.libaxolotl.ecc.Curve;
-import org.whispersystems.libaxolotl.ecc.ECKeyPair;
+import org.whispersystems.libsignal.ecc.Curve;
+import org.whispersystems.libsignal.ecc.ECKeyPair;
 
 public class CurveTest extends TestCase {
 

android/src/main/AndroidManifest.xml

@@ -1,3 +1,3 @@
 <manifest xmlns:android="http://schemas.android.com/apk/res/android"
-          package="org.whispersystems.libaxolotl">
+          package="org.whispersystems.libsignal">
 </manifest>

android/src/main/java/org/whispersystems/libaxolotl/util/AndroidAxolotlLogger.java

@@ -1,24 +0,0 @@
-package org.whispersystems.libaxolotl.util;
-
-import android.util.Log;
-import android.util.SparseIntArray;
-
-import org.whispersystems.libaxolotl.logging.AxolotlLogger;
-
-public class AndroidAxolotlLogger implements AxolotlLogger {
-
-  private static final SparseIntArray PRIORITY_MAP = new SparseIntArray(5) {{
-    put(AxolotlLogger.INFO, Log.INFO);
-    put(AxolotlLogger.ASSERT, Log.ASSERT);
-    put(AxolotlLogger.DEBUG, Log.DEBUG);
-    put(AxolotlLogger.VERBOSE, Log.VERBOSE);
-    put(AxolotlLogger.WARN, Log.WARN);
-
-  }};
-
-  @Override
-  public void log(int priority, String tag, String message) {
-    int androidPriority = PRIORITY_MAP.get(priority, Log.WARN);
-    Log.println(androidPriority, tag, message);
-  }
-}

android/src/main/java/org/whispersystems/libsignal/util/AndroidSignalProtocolLogger.java

@@ -0,0 +1,29 @@
+/**
+ * Copyright (C) 2014-2016 Open Whisper Systems
+ *
+ * Licensed according to the LICENSE file in this repository.
+ */
+package org.whispersystems.libsignal.util;
+
+import android.util.Log;
+import android.util.SparseIntArray;
+
+import org.whispersystems.libsignal.logging.SignalProtocolLogger;
+
+public class AndroidSignalProtocolLogger implements SignalProtocolLogger {
+
+  private static final SparseIntArray PRIORITY_MAP = new SparseIntArray(5) {{
+    put(SignalProtocolLogger.INFO, Log.INFO);
+    put(SignalProtocolLogger.ASSERT, Log.ASSERT);
+    put(SignalProtocolLogger.DEBUG, Log.DEBUG);
+    put(SignalProtocolLogger.VERBOSE, Log.VERBOSE);
+    put(SignalProtocolLogger.WARN, Log.WARN);
+
+  }};
+
+  @Override
+  public void log(int priority, String tag, String message) {
+    int androidPriority = PRIORITY_MAP.get(priority, Log.WARN);
+    Log.println(androidPriority, tag, message);
+  }
+}

build.gradle

@@ -1,7 +1,7 @@
 subprojects {
-    ext.version_number     = "1.3.4"
+    ext.version_number     = "2.8.1"
     ext.group_info         = "org.whispersystems"
-    ext.curve25519_version = "0.2.4"
+    ext.curve25519_version = "0.5.0"
 
     if (JavaVersion.current().isJava8Compatible()) {
         allprojects {

gradle/wrapper/gradle-wrapper.properties

@@ -1,6 +1,7 @@
-#Tue Dec 09 10:15:39 PST 2014
+# Note: Check https://gradle.org/release-checksums/ before updating wrapper or distribution
 distributionBase=GRADLE_USER_HOME
 distributionPath=wrapper/dists
+distributionSha256Sum=027fdd265d277bae65a0d349b6b8da02135b0b8e14ba891e26281fa877fe37a2
+distributionUrl=https\://services.gradle.org/distributions/gradle-5.6.2-all.zip
 zipStoreBase=GRADLE_USER_HOME
 zipStorePath=wrapper/dists
-distributionUrl=https\://services.gradle.org/distributions/gradle-2.2.1-all.zip

gradlew

@@ -1,4 +1,20 @@
-#!/usr/bin/env bash
+#!/usr/bin/env sh
+
+#
+# Copyright 2015 the original author or authors.
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#      https://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+#
 
 ##############################################################################
 ##
@@ -6,47 +22,6 @@
 ##
 ##############################################################################
 
-# Add default JVM options here. You can also use JAVA_OPTS and GRADLE_OPTS to pass JVM options to this script.
-DEFAULT_JVM_OPTS=""
-
-APP_NAME="Gradle"
-APP_BASE_NAME=`basename "$0"`
-
-# Use the maximum available, or set MAX_FD != -1 to use that value.
-MAX_FD="maximum"
-
-warn ( ) {
-    echo "$*"
-}
-
-die ( ) {
-    echo
-    echo "$*"
-    echo
-    exit 1
-}
-
-# OS specific support (must be 'true' or 'false').
-cygwin=false
-msys=false
-darwin=false
-case "`uname`" in
-  CYGWIN* )
-    cygwin=true
-    ;;
-  Darwin* )
-    darwin=true
-    ;;
-  MINGW* )
-    msys=true
-    ;;
-esac
-
-# For Cygwin, ensure paths are in UNIX format before anything is touched.
-if $cygwin ; then
-    [ -n "$JAVA_HOME" ] && JAVA_HOME=`cygpath --unix "$JAVA_HOME"`
-fi
-
 # Attempt to set APP_HOME
 # Resolve links: $0 may be a link
 PRG="$0"
@@ -61,9 +36,49 @@ while [ -h "$PRG" ] ; do
     fi
 done
 SAVED="`pwd`"
-cd "`dirname \"$PRG\"`/" >&-
+cd "`dirname \"$PRG\"`/" >/dev/null
 APP_HOME="`pwd -P`"
-cd "$SAVED" >&-
+cd "$SAVED" >/dev/null
+
+APP_NAME="Gradle"
+APP_BASE_NAME=`basename "$0"`
+
+# Add default JVM options here. You can also use JAVA_OPTS and GRADLE_OPTS to pass JVM options to this script.
+DEFAULT_JVM_OPTS='"-Xmx64m" "-Xms64m"'
+
+# Use the maximum available, or set MAX_FD != -1 to use that value.
+MAX_FD="maximum"
+
+warn () {
+    echo "$*"
+}
+
+die () {
+    echo
+    echo "$*"
+    echo
+    exit 1
+}
+
+# OS specific support (must be 'true' or 'false').
+cygwin=false
+msys=false
+darwin=false
+nonstop=false
+case "`uname`" in
+  CYGWIN* )
+    cygwin=true
+    ;;
+  Darwin* )
+    darwin=true
+    ;;
+  MINGW* )
+    msys=true
+    ;;
+  NONSTOP* )
+    nonstop=true
+    ;;
+esac
 
 CLASSPATH=$APP_HOME/gradle/wrapper/gradle-wrapper.jar
 
@@ -90,7 +105,7 @@ location of your Java installation."
 fi
 
 # Increase the maximum file descriptors if we can.
-if [ "$cygwin" = "false" -a "$darwin" = "false" ] ; then
+if [ "$cygwin" = "false" -a "$darwin" = "false" -a "$nonstop" = "false" ] ; then
     MAX_FD_LIMIT=`ulimit -H -n`
     if [ $? -eq 0 ] ; then
         if [ "$MAX_FD" = "maximum" -o "$MAX_FD" = "max" ] ; then
@@ -110,10 +125,11 @@ if $darwin; then
     GRADLE_OPTS="$GRADLE_OPTS \"-Xdock:name=$APP_NAME\" \"-Xdock:icon=$APP_HOME/media/gradle.icns\""
 fi
 
-# For Cygwin, switch paths to Windows format before running java
-if $cygwin ; then
+# For Cygwin or MSYS, switch paths to Windows format before running java
+if [ "$cygwin" = "true" -o "$msys" = "true" ] ; then
     APP_HOME=`cygpath --path --mixed "$APP_HOME"`
     CLASSPATH=`cygpath --path --mixed "$CLASSPATH"`
+    JAVACMD=`cygpath --unix "$JAVACMD"`
 
     # We build the pattern for arguments to be converted via cygpath
     ROOTDIRSRAW=`find -L / -maxdepth 1 -mindepth 1 -type d 2>/dev/null`
@@ -154,11 +170,19 @@ if $cygwin ; then
     esac
 fi
 
-# Split up the JVM_OPTS And GRADLE_OPTS values into an array, following the shell quoting and substitution rules
-function splitJvmOpts() {
-    JVM_OPTS=("$@")
+# Escape application args
+save () {
+    for i do printf %s\\n "$i" | sed "s/'/'\\\\''/g;1s/^/'/;\$s/\$/' \\\\/" ; done
+    echo " "
 }
-eval splitJvmOpts $DEFAULT_JVM_OPTS $JAVA_OPTS $GRADLE_OPTS
-JVM_OPTS[${#JVM_OPTS[*]}]="-Dorg.gradle.appname=$APP_BASE_NAME"
+APP_ARGS=$(save "$@")
 
-exec "$JAVACMD" "${JVM_OPTS[@]}" -classpath "$CLASSPATH" org.gradle.wrapper.GradleWrapperMain "$@"
+# Collect all arguments for the java command, following the shell quoting and substitution rules
+eval set -- $DEFAULT_JVM_OPTS $JAVA_OPTS $GRADLE_OPTS "\"-Dorg.gradle.appname=$APP_BASE_NAME\"" -classpath "\"$CLASSPATH\"" org.gradle.wrapper.GradleWrapperMain "$APP_ARGS"
+
+# by default we should be in the correct project dir, but when run from Finder on Mac, the cwd is wrong
+if [ "$(uname)" = "Darwin" ] && [ "$HOME" = "$PWD" ]; then
+  cd "$(dirname "$0")"
+fi
+
+exec "$JAVACMD" "$@"

gradlew.bat

@@ -1,3 +1,19 @@
+@rem
+@rem Copyright 2015 the original author or authors.
+@rem
+@rem Licensed under the Apache License, Version 2.0 (the "License");
+@rem you may not use this file except in compliance with the License.
+@rem You may obtain a copy of the License at
+@rem
+@rem      https://www.apache.org/licenses/LICENSE-2.0
+@rem
+@rem Unless required by applicable law or agreed to in writing, software
+@rem distributed under the License is distributed on an "AS IS" BASIS,
+@rem WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+@rem See the License for the specific language governing permissions and
+@rem limitations under the License.
+@rem
+
 @if "%DEBUG%" == "" @echo off
 @rem ##########################################################################
 @rem
@@ -8,14 +24,14 @@
 @rem Set local scope for the variables with windows NT shell
 if "%OS%"=="Windows_NT" setlocal
 
-@rem Add default JVM options here. You can also use JAVA_OPTS and GRADLE_OPTS to pass JVM options to this script.
-set DEFAULT_JVM_OPTS=
-
 set DIRNAME=%~dp0
 if "%DIRNAME%" == "" set DIRNAME=.
 set APP_BASE_NAME=%~n0
 set APP_HOME=%DIRNAME%
 
+@rem Add default JVM options here. You can also use JAVA_OPTS and GRADLE_OPTS to pass JVM options to this script.
+set DEFAULT_JVM_OPTS="-Xmx64m" "-Xms64m"
+
 @rem Find java.exe
 if defined JAVA_HOME goto findJavaFromJavaHome
 
@@ -46,10 +62,9 @@ echo location of your Java installation.
 goto fail
 
 :init
-@rem Get command-line arguments, handling Windowz variants
+@rem Get command-line arguments, handling Windows variants
 
 if not "%OS%" == "Windows_NT" goto win9xME_args
-if "%@eval[2+2]" == "4" goto 4NT_args
 
 :win9xME_args
 @rem Slurp the command line arguments.
@@ -60,11 +75,6 @@ set _SKIP=2
 if "x%~1" == "x" goto execute
 
 set CMD_LINE_ARGS=%*
-goto execute
-
-:4NT_args
-@rem Get arguments from the 4NT Shell from JP Software
-set CMD_LINE_ARGS=%$
 
 :execute
 @rem Setup the command line

java/build.gradle

@@ -1,9 +1,21 @@
+buildscript {
+    repositories {
+        google()
+        mavenCentral()
+    }
+
+    dependencies {
+        classpath 'com.google.protobuf:protobuf-gradle-plugin:0.8.10'
+    }
+}
+
 apply plugin: 'java'
+apply plugin: 'com.google.protobuf'
 apply plugin: 'maven'
 apply plugin: 'signing'
 
 sourceCompatibility = 1.7
-archivesBaseName = "axolotl-java"
+archivesBaseName = "signal-protocol-java"
 version          = version_number
 group            = group_info
 
@@ -22,11 +34,30 @@ sourceSets {
 
 dependencies {
     compile "org.whispersystems:curve25519-java:${curve25519_version}"
-    compile 'com.google.protobuf:protobuf-java:2.5.0'
+    compile 'com.google.protobuf:protobuf-javalite:3.10.0'
 
     testCompile ('junit:junit:3.8.2')
 }
 
+protobuf {
+    protoc {
+        artifact = 'com.google.protobuf:protoc:3.10.0'
+    }
+    generateProtoTasks {
+        all().each { task ->
+            task.builtins {
+                java {
+                    option "lite"
+                }
+            }
+        }
+    }
+}
+
+sourceSets {
+    main.proto.srcDir '../protobuf'
+}
+
 
 test {
     testLogging {
@@ -37,8 +68,25 @@ test {
     include 'org/whispersystems/**'
 }
 
+def isReleaseBuild() {
+    return version.contains("SNAPSHOT") == false
+}
+
+def getReleaseRepositoryUrl() {
+    return hasProperty('sonatypeRepo') ? sonatypeRepo
+            : "https://oss.sonatype.org/service/local/staging/deploy/maven2/"
+}
+
+def getRepositoryUsername() {
+    return hasProperty('whisperSonatypeUsername') ? whisperSonatypeUsername : ""
+}
+
+def getRepositoryPassword() {
+    return hasProperty('whisperSonatypePassword') ? whisperSonatypePassword : ""
+}
+
 signing {
-    required { has("release") && gradle.taskGraph.hasTask("uploadArchives") }
+    required { isReleaseBuild() && gradle.taskGraph.hasTask("uploadArchives") }
     sign configurations.archives
 }
 
@@ -47,20 +95,20 @@ uploadArchives {
     repositories.mavenDeployer {
         beforeDeployment { MavenDeployment deployment -> signing.signPom(deployment) }
 
-        repository(url: sonatypeRepo) {
-            authentication(userName: whisperSonatypeUsername, password: whisperSonatypePassword)
+        repository(url: getReleaseRepositoryUrl()) {
+            authentication(userName: getRepositoryUsername(), password: getRepositoryPassword())
         }
 
         pom.project {
-            name 'axolotl-java'
+            name 'signal-protocol-java'
             packaging 'jar'
-            description 'Axolotl library for Java'
-            url 'https://github.com/WhisperSystems/libaxolotl-android'
+            description 'Signal Protocol cryptography library for Java'
+            url 'https://github.com/WhisperSystems/libsignal-android'
 
             scm {
-                url 'scm:git@github.com:WhisperSystems/libaxolotl-android.git'
-                connection 'scm:git@github.com:WhisperSystems/libaxolotl-android.git'
-                developerConnection 'scm:git@github.com:WhisperSystems/libaxolotl-android.git'
+                url 'scm:git@github.com:WhisperSystems/libsignal-android.git'
+                connection 'scm:git@github.com:WhisperSystems/libsignal-android.git'
+                developerConnection 'scm:git@github.com:WhisperSystems/libsignal-android.git'
             }
 
             licenses {

java/src/main/java/org/whispersystems/libaxolotl/DecryptionCallback.java

@@ -1,5 +0,0 @@
-package org.whispersystems.libaxolotl;
-
-public interface DecryptionCallback {
-  public void handlePlaintext(byte[] plaintext);
-}

java/src/main/java/org/whispersystems/libaxolotl/DuplicateMessageException.java

@@ -1,7 +0,0 @@
-package org.whispersystems.libaxolotl;
-
-public class DuplicateMessageException extends Exception {
-  public DuplicateMessageException(String s) {
-    super(s);
-  }
-}

java/src/main/java/org/whispersystems/libaxolotl/InvalidKeyException.java

@@ -1,34 +0,0 @@
-/** 
- * Copyright (C) 2014 Open Whisper Systems
- * 
- * This program is free software: you can redistribute it and/or modify
- * it under the terms of the GNU General Public License as published by
- * the Free Software Foundation, either version 3 of the License, or
- * (at your option) any later version.
- *
- * This program is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
- * GNU General Public License for more details.
- * 
- * You should have received a copy of the GNU General Public License
- * along with this program.  If not, see <http://www.gnu.org/licenses/>.
- */
-package org.whispersystems.libaxolotl;
-
-public class InvalidKeyException extends Exception {
-
-  public InvalidKeyException() {}
-
-  public InvalidKeyException(String detailMessage) {
-    super(detailMessage);
-  }
-
-  public InvalidKeyException(Throwable throwable) {
-    super(throwable);
-  }
-
-  public InvalidKeyException(String detailMessage, Throwable throwable) {
-    super(detailMessage, throwable);
-  }
-}

java/src/main/java/org/whispersystems/libaxolotl/InvalidKeyIdException.java

@@ -1,27 +0,0 @@
-/** 
- * Copyright (C) 2014 Open Whisper Systems
- * 
- * This program is free software: you can redistribute it and/or modify
- * it under the terms of the GNU General Public License as published by
- * the Free Software Foundation, either version 3 of the License, or
- * (at your option) any later version.
- *
- * This program is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
- * GNU General Public License for more details.
- * 
- * You should have received a copy of the GNU General Public License
- * along with this program.  If not, see <http://www.gnu.org/licenses/>.
- */
-package org.whispersystems.libaxolotl;
-
-public class InvalidKeyIdException extends Exception {
-  public InvalidKeyIdException(String detailMessage) {
-    super(detailMessage);
-  }
-
-  public InvalidKeyIdException(Throwable throwable) {
-    super(throwable);
-  }
-}

java/src/main/java/org/whispersystems/libaxolotl/InvalidMacException.java

@@ -1,28 +0,0 @@
-/** 
- * Copyright (C) 2014 Open Whisper Systems
- * 
- * This program is free software: you can redistribute it and/or modify
- * it under the terms of the GNU General Public License as published by
- * the Free Software Foundation, either version 3 of the License, or
- * (at your option) any later version.
- *
- * This program is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
- * GNU General Public License for more details.
- * 
- * You should have received a copy of the GNU General Public License
- * along with this program.  If not, see <http://www.gnu.org/licenses/>.
- */
-package org.whispersystems.libaxolotl;
-
-public class InvalidMacException extends Exception {
-
-  public InvalidMacException(String detailMessage) {
-    super(detailMessage);
-  }
-
-  public InvalidMacException(Throwable throwable) {
-    super(throwable);
-  }
-}

java/src/main/java/org/whispersystems/libaxolotl/InvalidMessageException.java

@@ -1,40 +0,0 @@
-/** 
- * Copyright (C) 2014 Open Whisper Systems
- * 
- * This program is free software: you can redistribute it and/or modify
- * it under the terms of the GNU General Public License as published by
- * the Free Software Foundation, either version 3 of the License, or
- * (at your option) any later version.
- *
- * This program is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
- * GNU General Public License for more details.
- * 
- * You should have received a copy of the GNU General Public License
- * along with this program.  If not, see <http://www.gnu.org/licenses/>.
- */
-package org.whispersystems.libaxolotl;
-
-import java.util.List;
-
-public class InvalidMessageException extends Exception {
-
-  public InvalidMessageException() {}
-
-  public InvalidMessageException(String detailMessage) {
-    super(detailMessage);
-  }
-
-  public InvalidMessageException(Throwable throwable) {
-    super(throwable);
-  }
-
-  public InvalidMessageException(String detailMessage, Throwable throwable) {
-    super(detailMessage, throwable);
-  }
-
-  public InvalidMessageException(String detailMessage, List<Exception> exceptions) {
-    super(detailMessage, exceptions.get(0));
-  }
-}

java/src/main/java/org/whispersystems/libaxolotl/InvalidVersionException.java

@@ -1,23 +0,0 @@
-/**
- * Copyright (C) 2014 Open Whisper Systems
- *
- * This program is free software: you can redistribute it and/or modify
- * it under the terms of the GNU General Public License as published by
- * the Free Software Foundation, either version 3 of the License, or
- * (at your option) any later version.
- *
- * This program is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
- * GNU General Public License for more details.
- *
- * You should have received a copy of the GNU General Public License
- * along with this program.  If not, see <http://www.gnu.org/licenses/>.
- */
-package org.whispersystems.libaxolotl;
-
-public class InvalidVersionException extends Exception {
-  public InvalidVersionException(String detailMessage) {
-    super(detailMessage);
-  }
-}

java/src/main/java/org/whispersystems/libaxolotl/LegacyMessageException.java

@@ -1,7 +0,0 @@
-package org.whispersystems.libaxolotl;
-
-public class LegacyMessageException extends Exception {
-  public LegacyMessageException(String s) {
-    super(s);
-  }
-}

java/src/main/java/org/whispersystems/libaxolotl/SessionBuilder.java

@@ -1,407 +0,0 @@
-package org.whispersystems.libaxolotl;
-
-
-import org.whispersystems.libaxolotl.ecc.Curve;
-import org.whispersystems.libaxolotl.ecc.ECKeyPair;
-import org.whispersystems.libaxolotl.ecc.ECPublicKey;
-import org.whispersystems.libaxolotl.logging.Log;
-import org.whispersystems.libaxolotl.protocol.CiphertextMessage;
-import org.whispersystems.libaxolotl.protocol.KeyExchangeMessage;
-import org.whispersystems.libaxolotl.protocol.PreKeyWhisperMessage;
-import org.whispersystems.libaxolotl.ratchet.AliceAxolotlParameters;
-import org.whispersystems.libaxolotl.ratchet.BobAxolotlParameters;
-import org.whispersystems.libaxolotl.ratchet.RatchetingSession;
-import org.whispersystems.libaxolotl.ratchet.SymmetricAxolotlParameters;
-import org.whispersystems.libaxolotl.state.AxolotlStore;
-import org.whispersystems.libaxolotl.state.IdentityKeyStore;
-import org.whispersystems.libaxolotl.state.PreKeyBundle;
-import org.whispersystems.libaxolotl.state.PreKeyStore;
-import org.whispersystems.libaxolotl.state.SessionRecord;
-import org.whispersystems.libaxolotl.state.SessionState;
-import org.whispersystems.libaxolotl.state.SessionStore;
-import org.whispersystems.libaxolotl.state.SignedPreKeyStore;
-import org.whispersystems.libaxolotl.util.KeyHelper;
-import org.whispersystems.libaxolotl.util.Medium;
-import org.whispersystems.libaxolotl.util.guava.Optional;
-
-/**
- * SessionBuilder is responsible for setting up encrypted sessions.
- * Once a session has been established, {@link org.whispersystems.libaxolotl.SessionCipher}
- * can be used to encrypt/decrypt messages in that session.
- * <p>
- * Sessions are built from one of three different possible vectors:
- * <ol>
- *   <li>A {@link org.whispersystems.libaxolotl.state.PreKeyBundle} retrieved from a server.</li>
- *   <li>A {@link org.whispersystems.libaxolotl.protocol.PreKeyWhisperMessage} received from a client.</li>
- *   <li>A {@link org.whispersystems.libaxolotl.protocol.KeyExchangeMessage} sent to or received from a client.</li>
- * </ol>
- *
- * Sessions are constructed per recipientId + deviceId tuple.  Remote logical users are identified
- * by their recipientId, and each logical recipientId can have multiple physical devices.
- *
- * @author Moxie Marlinspike
- */
-public class SessionBuilder {
-
-  private static final String TAG = SessionBuilder.class.getSimpleName();
-
-  private final SessionStore      sessionStore;
-  private final PreKeyStore       preKeyStore;
-  private final SignedPreKeyStore signedPreKeyStore;
-  private final IdentityKeyStore  identityKeyStore;
-  private final AxolotlAddress    remoteAddress;
-
-  /**
-   * Constructs a SessionBuilder.
-   *
-   * @param sessionStore The {@link org.whispersystems.libaxolotl.state.SessionStore} to store the constructed session in.
-   * @param preKeyStore The {@link  org.whispersystems.libaxolotl.state.PreKeyStore} where the client's local {@link org.whispersystems.libaxolotl.state.PreKeyRecord}s are stored.
-   * @param identityKeyStore The {@link org.whispersystems.libaxolotl.state.IdentityKeyStore} containing the client's identity key information.
-   * @param remoteAddress The address of the remote user to build a session with.
-   */
-  public SessionBuilder(SessionStore sessionStore,
-                        PreKeyStore preKeyStore,
-                        SignedPreKeyStore signedPreKeyStore,
-                        IdentityKeyStore identityKeyStore,
-                        AxolotlAddress remoteAddress)
-  {
-    this.sessionStore      = sessionStore;
-    this.preKeyStore       = preKeyStore;
-    this.signedPreKeyStore = signedPreKeyStore;
-    this.identityKeyStore  = identityKeyStore;
-    this.remoteAddress     = remoteAddress;
-  }
-
-  /**
-   * Constructs a SessionBuilder
-   * @param store The {@link org.whispersystems.libaxolotl.state.AxolotlStore} to store all state information in.
-   * @param remoteAddress The address of the remote user to build a session with.
-   */
-  public SessionBuilder(AxolotlStore store, AxolotlAddress remoteAddress) {
-    this(store, store, store, store, remoteAddress);
-  }
-
-  /**
-   * Build a new session from a received {@link org.whispersystems.libaxolotl.protocol.PreKeyWhisperMessage}.
-   *
-   * After a session is constructed in this way, the embedded {@link org.whispersystems.libaxolotl.protocol.WhisperMessage}
-   * can be decrypted.
-   *
-   * @param message The received {@link org.whispersystems.libaxolotl.protocol.PreKeyWhisperMessage}.
-   * @throws org.whispersystems.libaxolotl.InvalidKeyIdException when there is no local
-   *                                                             {@link org.whispersystems.libaxolotl.state.PreKeyRecord}
-   *                                                             that corresponds to the PreKey ID in
-   *                                                             the message.
-   * @throws org.whispersystems.libaxolotl.InvalidKeyException when the message is formatted incorrectly.
-   * @throws org.whispersystems.libaxolotl.UntrustedIdentityException when the {@link IdentityKey} of the sender is untrusted.
-   */
-  /*package*/ Optional<Integer> process(SessionRecord sessionRecord, PreKeyWhisperMessage message)
-      throws InvalidKeyIdException, InvalidKeyException, UntrustedIdentityException
-  {
-    int         messageVersion   = message.getMessageVersion();
-    IdentityKey theirIdentityKey = message.getIdentityKey();
-
-    Optional<Integer> unsignedPreKeyId;
-
-    if (!identityKeyStore.isTrustedIdentity(remoteAddress.getName(), theirIdentityKey)) {
-      throw new UntrustedIdentityException(remoteAddress.getName(), theirIdentityKey);
-    }
-
-    switch (messageVersion) {
-      case 2:  unsignedPreKeyId = processV2(sessionRecord, message); break;
-      case 3:  unsignedPreKeyId = processV3(sessionRecord, message); break;
-      default: throw new AssertionError("Unknown version: " + messageVersion);
-    }
-
-    identityKeyStore.saveIdentity(remoteAddress.getName(), theirIdentityKey);
-    return unsignedPreKeyId;
-  }
-
-  private Optional<Integer> processV3(SessionRecord sessionRecord, PreKeyWhisperMessage message)
-      throws UntrustedIdentityException, InvalidKeyIdException, InvalidKeyException
-  {
-
-    if (sessionRecord.hasSessionState(message.getMessageVersion(), message.getBaseKey().serialize())) {
-      Log.w(TAG, "We've already setup a session for this V3 message, letting bundled message fall through...");
-      return Optional.absent();
-    }
-
-    ECKeyPair ourSignedPreKey = signedPreKeyStore.loadSignedPreKey(message.getSignedPreKeyId()).getKeyPair();
-
-    BobAxolotlParameters.Builder parameters = BobAxolotlParameters.newBuilder();
-
-    parameters.setTheirBaseKey(message.getBaseKey())
-              .setTheirIdentityKey(message.getIdentityKey())
-              .setOurIdentityKey(identityKeyStore.getIdentityKeyPair())
-              .setOurSignedPreKey(ourSignedPreKey)
-              .setOurRatchetKey(ourSignedPreKey);
-
-    if (message.getPreKeyId().isPresent()) {
-      parameters.setOurOneTimePreKey(Optional.of(preKeyStore.loadPreKey(message.getPreKeyId().get()).getKeyPair()));
-    } else {
-      parameters.setOurOneTimePreKey(Optional.<ECKeyPair>absent());
-    }
-
-    if (!sessionRecord.isFresh()) sessionRecord.archiveCurrentState();
-
-    RatchetingSession.initializeSession(sessionRecord.getSessionState(), message.getMessageVersion(), parameters.create());
-
-    sessionRecord.getSessionState().setLocalRegistrationId(identityKeyStore.getLocalRegistrationId());
-    sessionRecord.getSessionState().setRemoteRegistrationId(message.getRegistrationId());
-    sessionRecord.getSessionState().setAliceBaseKey(message.getBaseKey().serialize());
-
-    if (message.getPreKeyId().isPresent() && message.getPreKeyId().get() != Medium.MAX_VALUE) {
-      return message.getPreKeyId();
-    } else {
-      return Optional.absent();
-    }
-  }
-
-  private Optional<Integer> processV2(SessionRecord sessionRecord, PreKeyWhisperMessage message)
-      throws UntrustedIdentityException, InvalidKeyIdException, InvalidKeyException
-  {
-    if (!message.getPreKeyId().isPresent()) {
-      throw new InvalidKeyIdException("V2 message requires one time prekey id!");
-    }
-
-    if (!preKeyStore.containsPreKey(message.getPreKeyId().get()) &&
-        sessionStore.containsSession(remoteAddress))
-    {
-      Log.w(TAG, "We've already processed the prekey part of this V2 session, letting bundled message fall through...");
-      return Optional.absent();
-    }
-
-    ECKeyPair ourPreKey = preKeyStore.loadPreKey(message.getPreKeyId().get()).getKeyPair();
-
-    BobAxolotlParameters.Builder parameters = BobAxolotlParameters.newBuilder();
-
-    parameters.setOurIdentityKey(identityKeyStore.getIdentityKeyPair())
-              .setOurSignedPreKey(ourPreKey)
-              .setOurRatchetKey(ourPreKey)
-              .setOurOneTimePreKey(Optional.<ECKeyPair>absent())
-              .setTheirIdentityKey(message.getIdentityKey())
-              .setTheirBaseKey(message.getBaseKey());
-
-    if (!sessionRecord.isFresh()) sessionRecord.archiveCurrentState();
-
-    RatchetingSession.initializeSession(sessionRecord.getSessionState(), message.getMessageVersion(), parameters.create());
-
-    sessionRecord.getSessionState().setLocalRegistrationId(identityKeyStore.getLocalRegistrationId());
-    sessionRecord.getSessionState().setRemoteRegistrationId(message.getRegistrationId());
-    sessionRecord.getSessionState().setAliceBaseKey(message.getBaseKey().serialize());
-
-    if (message.getPreKeyId().get() != Medium.MAX_VALUE) {
-      return message.getPreKeyId();
-    } else {
-      return Optional.absent();
-    }
-  }
-
-  /**
-   * Build a new session from a {@link org.whispersystems.libaxolotl.state.PreKeyBundle} retrieved from
-   * a server.
-   *
-   * @param preKey A PreKey for the destination recipient, retrieved from a server.
-   * @throws InvalidKeyException when the {@link org.whispersystems.libaxolotl.state.PreKeyBundle} is
-   *                             badly formatted.
-   * @throws org.whispersystems.libaxolotl.UntrustedIdentityException when the sender's
-   *                                                                  {@link IdentityKey} is not
-   *                                                                  trusted.
-   */
-  public void process(PreKeyBundle preKey) throws InvalidKeyException, UntrustedIdentityException {
-    synchronized (SessionCipher.SESSION_LOCK) {
-      if (!identityKeyStore.isTrustedIdentity(remoteAddress.getName(), preKey.getIdentityKey())) {
-        throw new UntrustedIdentityException(remoteAddress.getName(), preKey.getIdentityKey());
-      }
-
-      if (preKey.getSignedPreKey() != null &&
-          !Curve.verifySignature(preKey.getIdentityKey().getPublicKey(),
-                                 preKey.getSignedPreKey().serialize(),
-                                 preKey.getSignedPreKeySignature()))
-      {
-        throw new InvalidKeyException("Invalid signature on device key!");
-      }
-
-      if (preKey.getSignedPreKey() == null && preKey.getPreKey() == null) {
-        throw new InvalidKeyException("Both signed and unsigned prekeys are absent!");
-      }
-
-      boolean               supportsV3           = preKey.getSignedPreKey() != null;
-      SessionRecord         sessionRecord        = sessionStore.loadSession(remoteAddress);
-      ECKeyPair             ourBaseKey           = Curve.generateKeyPair();
-      ECPublicKey           theirSignedPreKey    = supportsV3 ? preKey.getSignedPreKey() : preKey.getPreKey();
-      Optional<ECPublicKey> theirOneTimePreKey   = Optional.fromNullable(preKey.getPreKey());
-      Optional<Integer>     theirOneTimePreKeyId = theirOneTimePreKey.isPresent() ? Optional.of(preKey.getPreKeyId()) :
-                                                                                    Optional.<Integer>absent();
-
-      AliceAxolotlParameters.Builder parameters = AliceAxolotlParameters.newBuilder();
-
-      parameters.setOurBaseKey(ourBaseKey)
-                .setOurIdentityKey(identityKeyStore.getIdentityKeyPair())
-                .setTheirIdentityKey(preKey.getIdentityKey())
-                .setTheirSignedPreKey(theirSignedPreKey)
-                .setTheirRatchetKey(theirSignedPreKey)
-                .setTheirOneTimePreKey(supportsV3 ? theirOneTimePreKey : Optional.<ECPublicKey>absent());
-
-      if (!sessionRecord.isFresh()) sessionRecord.archiveCurrentState();
-
-      RatchetingSession.initializeSession(sessionRecord.getSessionState(),
-                                          supportsV3 ? 3 : 2,
-                                          parameters.create());
-
-      sessionRecord.getSessionState().setUnacknowledgedPreKeyMessage(theirOneTimePreKeyId, preKey.getSignedPreKeyId(), ourBaseKey.getPublicKey());
-      sessionRecord.getSessionState().setLocalRegistrationId(identityKeyStore.getLocalRegistrationId());
-      sessionRecord.getSessionState().setRemoteRegistrationId(preKey.getRegistrationId());
-      sessionRecord.getSessionState().setAliceBaseKey(ourBaseKey.getPublicKey().serialize());
-
-      sessionStore.storeSession(remoteAddress, sessionRecord);
-      identityKeyStore.saveIdentity(remoteAddress.getName(), preKey.getIdentityKey());
-    }
-  }
-
-  /**
-   * Build a new session from a {@link org.whispersystems.libaxolotl.protocol.KeyExchangeMessage}
-   * received from a remote client.
-   *
-   * @param message The received KeyExchangeMessage.
-   * @return The KeyExchangeMessage to respond with, or null if no response is necessary.
-   * @throws InvalidKeyException if the received KeyExchangeMessage is badly formatted.
-   */
-  public KeyExchangeMessage process(KeyExchangeMessage message)
-      throws InvalidKeyException, UntrustedIdentityException, StaleKeyExchangeException
-  {
-    synchronized (SessionCipher.SESSION_LOCK) {
-      if (!identityKeyStore.isTrustedIdentity(remoteAddress.getName(), message.getIdentityKey())) {
-        throw new UntrustedIdentityException(remoteAddress.getName(), message.getIdentityKey());
-      }
-
-      KeyExchangeMessage responseMessage = null;
-
-      if (message.isInitiate()) responseMessage = processInitiate(message);
-      else                      processResponse(message);
-
-      return responseMessage;
-    }
-  }
-
-  private KeyExchangeMessage processInitiate(KeyExchangeMessage message) throws InvalidKeyException {
-    int           flags         = KeyExchangeMessage.RESPONSE_FLAG;
-    SessionRecord sessionRecord = sessionStore.loadSession(remoteAddress);
-
-    if (message.getVersion() >= 3 &&
-        !Curve.verifySignature(message.getIdentityKey().getPublicKey(),
-                               message.getBaseKey().serialize(),
-                               message.getBaseKeySignature()))
-    {
-      throw new InvalidKeyException("Bad signature!");
-    }
-
-    SymmetricAxolotlParameters.Builder builder = SymmetricAxolotlParameters.newBuilder();
-
-    if (!sessionRecord.getSessionState().hasPendingKeyExchange()) {
-      builder.setOurIdentityKey(identityKeyStore.getIdentityKeyPair())
-             .setOurBaseKey(Curve.generateKeyPair())
-             .setOurRatchetKey(Curve.generateKeyPair());
-    } else {
-      builder.setOurIdentityKey(sessionRecord.getSessionState().getPendingKeyExchangeIdentityKey())
-             .setOurBaseKey(sessionRecord.getSessionState().getPendingKeyExchangeBaseKey())
-             .setOurRatchetKey(sessionRecord.getSessionState().getPendingKeyExchangeRatchetKey());
-      flags |= KeyExchangeMessage.SIMULTAENOUS_INITIATE_FLAG;
-    }
-
-    builder.setTheirBaseKey(message.getBaseKey())
-           .setTheirRatchetKey(message.getRatchetKey())
-           .setTheirIdentityKey(message.getIdentityKey());
-
-    SymmetricAxolotlParameters parameters = builder.create();
-
-    if (!sessionRecord.isFresh()) sessionRecord.archiveCurrentState();
-
-    RatchetingSession.initializeSession(sessionRecord.getSessionState(),
-                                        Math.min(message.getMaxVersion(), CiphertextMessage.CURRENT_VERSION),
-                                        parameters);
-
-    sessionStore.storeSession(remoteAddress, sessionRecord);
-    identityKeyStore.saveIdentity(remoteAddress.getName(), message.getIdentityKey());
-
-    byte[] baseKeySignature = Curve.calculateSignature(parameters.getOurIdentityKey().getPrivateKey(),
-                                                       parameters.getOurBaseKey().getPublicKey().serialize());
-
-    return new KeyExchangeMessage(sessionRecord.getSessionState().getSessionVersion(),
-                                  message.getSequence(), flags,
-                                  parameters.getOurBaseKey().getPublicKey(),
-                                  baseKeySignature, parameters.getOurRatchetKey().getPublicKey(),
-                                  parameters.getOurIdentityKey().getPublicKey());
-  }
-
-  private void processResponse(KeyExchangeMessage message)
-      throws StaleKeyExchangeException, InvalidKeyException
-  {
-    SessionRecord sessionRecord                  = sessionStore.loadSession(remoteAddress);
-    SessionState  sessionState                   = sessionRecord.getSessionState();
-    boolean       hasPendingKeyExchange          = sessionState.hasPendingKeyExchange();
-    boolean       isSimultaneousInitiateResponse = message.isResponseForSimultaneousInitiate();
-
-    if (!hasPendingKeyExchange || sessionState.getPendingKeyExchangeSequence() != message.getSequence()) {
-      Log.w(TAG, "No matching sequence for response. Is simultaneous initiate response: " + isSimultaneousInitiateResponse);
-      if (!isSimultaneousInitiateResponse) throw new StaleKeyExchangeException();
-      else                                 return;
-    }
-
-    SymmetricAxolotlParameters.Builder parameters = SymmetricAxolotlParameters.newBuilder();
-
-    parameters.setOurBaseKey(sessionRecord.getSessionState().getPendingKeyExchangeBaseKey())
-              .setOurRatchetKey(sessionRecord.getSessionState().getPendingKeyExchangeRatchetKey())
-              .setOurIdentityKey(sessionRecord.getSessionState().getPendingKeyExchangeIdentityKey())
-              .setTheirBaseKey(message.getBaseKey())
-              .setTheirRatchetKey(message.getRatchetKey())
-              .setTheirIdentityKey(message.getIdentityKey());
-
-    if (!sessionRecord.isFresh()) sessionRecord.archiveCurrentState();
-
-    RatchetingSession.initializeSession(sessionRecord.getSessionState(),
-                                        Math.min(message.getMaxVersion(), CiphertextMessage.CURRENT_VERSION),
-                                        parameters.create());
-
-    if (sessionRecord.getSessionState().getSessionVersion() >= 3 &&
-        !Curve.verifySignature(message.getIdentityKey().getPublicKey(),
-                               message.getBaseKey().serialize(),
-                               message.getBaseKeySignature()))
-    {
-      throw new InvalidKeyException("Base key signature doesn't match!");
-    }
-
-    sessionStore.storeSession(remoteAddress, sessionRecord);
-    identityKeyStore.saveIdentity(remoteAddress.getName(), message.getIdentityKey());
-
-  }
-
-  /**
-   * Initiate a new session by sending an initial KeyExchangeMessage to the recipient.
-   *
-   * @return the KeyExchangeMessage to deliver.
-   */
-  public KeyExchangeMessage process() {
-    synchronized (SessionCipher.SESSION_LOCK) {
-      try {
-        int             sequence         = KeyHelper.getRandomSequence(65534) + 1;
-        int             flags            = KeyExchangeMessage.INITIATE_FLAG;
-        ECKeyPair       baseKey          = Curve.generateKeyPair();
-        ECKeyPair       ratchetKey       = Curve.generateKeyPair();
-        IdentityKeyPair identityKey      = identityKeyStore.getIdentityKeyPair();
-        byte[]          baseKeySignature = Curve.calculateSignature(identityKey.getPrivateKey(), baseKey.getPublicKey().serialize());
-        SessionRecord   sessionRecord    = sessionStore.loadSession(remoteAddress);
-
-        sessionRecord.getSessionState().setPendingKeyExchange(sequence, baseKey, ratchetKey, identityKey);
-        sessionStore.storeSession(remoteAddress, sessionRecord);
-
-        return new KeyExchangeMessage(2, sequence, flags, baseKey.getPublicKey(), baseKeySignature,
-                                      ratchetKey.getPublicKey(), identityKey.getPublicKey());
-      } catch (InvalidKeyException e) {
-        throw new AssertionError(e);
-      }
-    }
-  }
-
-
-}

java/src/main/java/org/whispersystems/libaxolotl/StaleKeyExchangeException.java

@@ -1,4 +0,0 @@
-package org.whispersystems.libaxolotl;
-
-public class StaleKeyExchangeException extends Throwable {
-}

java/src/main/java/org/whispersystems/libaxolotl/ecc/DjbECPrivateKey.java

@@ -1,41 +0,0 @@
-/**
- * Copyright (C) 2013 Open Whisper Systems
- *
- * This program is free software: you can redistribute it and/or modify
- * it under the terms of the GNU General Public License as published by
- * the Free Software Foundation, either version 3 of the License, or
- * (at your option) any later version.
- *
- * This program is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
- * GNU General Public License for more details.
- *
- * You should have received a copy of the GNU General Public License
- * along with this program.  If not, see <http://www.gnu.org/licenses/>.
- */
-
-package org.whispersystems.libaxolotl.ecc;
-
-public class DjbECPrivateKey implements ECPrivateKey {
-
-  private final byte[] privateKey;
-
-  DjbECPrivateKey(byte[] privateKey) {
-    this.privateKey = privateKey;
-  }
-
-  @Override
-  public byte[] serialize() {
-    return privateKey;
-  }
-
-  @Override
-  public int getType() {
-    return Curve.DJB_TYPE;
-  }
-
-  public byte[] getPrivateKey() {
-    return privateKey;
-  }
-}

java/src/main/java/org/whispersystems/libaxolotl/ecc/ECKeyPair.java

@@ -1,37 +0,0 @@
-/**
- * Copyright (C) 2013 Open Whisper Systems
- *
- * This program is free software: you can redistribute it and/or modify
- * it under the terms of the GNU General Public License as published by
- * the Free Software Foundation, either version 3 of the License, or
- * (at your option) any later version.
- *
- * This program is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
- * GNU General Public License for more details.
- *
- * You should have received a copy of the GNU General Public License
- * along with this program.  If not, see <http://www.gnu.org/licenses/>.
- */
-
-package org.whispersystems.libaxolotl.ecc;
-
-public class ECKeyPair {
-
-  private final ECPublicKey  publicKey;
-  private final ECPrivateKey privateKey;
-
-  public ECKeyPair(ECPublicKey publicKey, ECPrivateKey privateKey) {
-    this.publicKey = publicKey;
-    this.privateKey = privateKey;
-  }
-
-  public ECPublicKey getPublicKey() {
-    return publicKey;
-  }
-
-  public ECPrivateKey getPrivateKey() {
-    return privateKey;
-  }
-}

java/src/main/java/org/whispersystems/libaxolotl/ecc/ECPrivateKey.java

@@ -1,23 +0,0 @@
-/**
- * Copyright (C) 2013 Open Whisper Systems
- *
- * This program is free software: you can redistribute it and/or modify
- * it under the terms of the GNU General Public License as published by
- * the Free Software Foundation, either version 3 of the License, or
- * (at your option) any later version.
- *
- * This program is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
- * GNU General Public License for more details.
- *
- * You should have received a copy of the GNU General Public License
- * along with this program.  If not, see <http://www.gnu.org/licenses/>.
- */
-
-package org.whispersystems.libaxolotl.ecc;
-
-public interface ECPrivateKey {
-  public byte[] serialize();
-  public int getType();
-}

java/src/main/java/org/whispersystems/libaxolotl/ecc/ECPublicKey.java

@@ -1,27 +0,0 @@
-/**
- * Copyright (C) 2013 Open Whisper Systems
- *
- * This program is free software: you can redistribute it and/or modify
- * it under the terms of the GNU General Public License as published by
- * the Free Software Foundation, either version 3 of the License, or
- * (at your option) any later version.
- *
- * This program is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
- * GNU General Public License for more details.
- *
- * You should have received a copy of the GNU General Public License
- * along with this program.  If not, see <http://www.gnu.org/licenses/>.
- */
-
-package org.whispersystems.libaxolotl.ecc;
-
-public interface ECPublicKey extends Comparable<ECPublicKey> {
-
-  public static final int KEY_SIZE = 33;
-
-  public byte[] serialize();
-
-  public int getType();
-}

java/src/main/java/org/whispersystems/libaxolotl/fingerprint/DisplayableFingerprint.java

@@ -1,20 +0,0 @@
-package org.whispersystems.libaxolotl.fingerprint;
-
-public class DisplayableFingerprint {
-
-  private final String localFingerprint;
-  private final String remoteFingerprint;
-
-  public DisplayableFingerprint(String localFingerprint, String remoteFingerprint) {
-    this.localFingerprint  = localFingerprint;
-    this.remoteFingerprint = remoteFingerprint;
-  }
-
-  public String getDisplayText() {
-    if (localFingerprint.compareTo(remoteFingerprint) <= 0) {
-      return localFingerprint + remoteFingerprint;
-    } else {
-      return remoteFingerprint + localFingerprint;
-    }
-  }
-}

java/src/main/java/org/whispersystems/libaxolotl/fingerprint/FingerprintGenerator.java

@@ -1,8 +0,0 @@
-package org.whispersystems.libaxolotl.fingerprint;
-
-import org.whispersystems.libaxolotl.IdentityKey;
-
-public interface FingerprintGenerator {
-  public Fingerprint createFor(String localStableIdentifier, IdentityKey localIdentityKey,
-                               String remoteStableIdentifier, IdentityKey remoteIdentityKey);
-}

java/src/main/java/org/whispersystems/libaxolotl/fingerprint/FingerprintVersionMismatchException.java

@@ -1,12 +0,0 @@
-package org.whispersystems.libaxolotl.fingerprint;
-
-public class FingerprintVersionMismatchException extends Exception {
-
-  public FingerprintVersionMismatchException() {
-    super();
-  }
-
-  public FingerprintVersionMismatchException(Exception e) {
-    super(e);
-  }
-}

java/src/main/java/org/whispersystems/libaxolotl/fingerprint/NumericFingerprintGenerator.java

@@ -1,82 +0,0 @@
-package org.whispersystems.libaxolotl.fingerprint;
-
-import org.whispersystems.libaxolotl.IdentityKey;
-import org.whispersystems.libaxolotl.util.ByteUtil;
-
-import java.security.MessageDigest;
-import java.security.NoSuchAlgorithmException;
-
-public class NumericFingerprintGenerator implements FingerprintGenerator {
-
-  private static final int VERSION = 0;
-
-  private final long iterations;
-
-  /**
-   * Construct a fingerprint generator for 60 digit numerics.
-   *
-   * @param iterations The number of internal iterations to perform in the process of
-   *                   generating a fingerprint. This needs to be constant, and synchronized
-   *                   across all clients.
-   *
-   *                   The higher the iteration count, the higher the security level:
-   *
-   *                   - 1024 ~ 109.7 bits
-   *                   - 1400 > 110 bits
-   *                   - 5200 > 112 bits
-   */
-  public NumericFingerprintGenerator(long iterations) {
-    this.iterations = iterations;
-  }
-
-  /**
-   * Generate a scannable and displayble fingerprint.
-   *
-   * @param localStableIdentifier The client's "stable" identifier.
-   * @param localIdentityKey The client's identity key.
-   * @param remoteStableIdentifier The remote party's "stable" identifier.
-   * @param remoteIdentityKey The remote party's identity key.
-   * @return A unique fingerprint for this conversation.
-   */
-  @Override
-  public Fingerprint createFor(String localStableIdentifier, IdentityKey localIdentityKey,
-                               String remoteStableIdentifier, IdentityKey remoteIdentityKey)
-  {
-    DisplayableFingerprint displayableFingerprint = new DisplayableFingerprint(getDisplayStringFor(localStableIdentifier, localIdentityKey),
-                                                                               getDisplayStringFor(remoteStableIdentifier, remoteIdentityKey));
-
-    ScannableFingerprint scannableFingerprint = new ScannableFingerprint(VERSION,
-                                                                         localStableIdentifier, localIdentityKey,
-                                                                         remoteStableIdentifier, remoteIdentityKey);
-
-    return new Fingerprint(displayableFingerprint, scannableFingerprint);
-  }
-
-  private String getDisplayStringFor(String stableIdentifier, IdentityKey identityKey) {
-    try {
-      MessageDigest digest = MessageDigest.getInstance("SHA-512");
-      byte[]        hash   = ByteUtil.combine(ByteUtil.shortToByteArray(VERSION),
-                                              identityKey.getPublicKey().serialize(),
-                                              stableIdentifier.getBytes());
-
-      for (int i=0;i<iterations;i++) {
-        hash = digest.digest(hash);
-      }
-
-      return getEncodedChunk(hash, 0) +
-          getEncodedChunk(hash, 5) +
-          getEncodedChunk(hash, 10) +
-          getEncodedChunk(hash, 15) +
-          getEncodedChunk(hash, 20) +
-          getEncodedChunk(hash, 25);
-    } catch (NoSuchAlgorithmException e) {
-      throw new AssertionError(e);
-    }
-  }
-
-  private String getEncodedChunk(byte[] hash, int offset) {
-    long chunk = ByteUtil.byteArray5ToLong(hash, offset) % 100000;
-    return String.format("%05d", chunk);
-  }
-
-}

java/src/main/java/org/whispersystems/libaxolotl/fingerprint/ScannableFingerprint.java

@@ -1,73 +0,0 @@
-package org.whispersystems.libaxolotl.fingerprint;
-
-import com.google.protobuf.ByteString;
-import com.google.protobuf.InvalidProtocolBufferException;
-
-import org.whispersystems.libaxolotl.IdentityKey;
-import org.whispersystems.libaxolotl.fingerprint.FingerprintProtos.CombinedFingerprint;
-import org.whispersystems.libaxolotl.fingerprint.FingerprintProtos.FingerprintData;
-
-import java.security.MessageDigest;
-
-public class ScannableFingerprint {
-
-  private final CombinedFingerprint combinedFingerprint;
-
-  public ScannableFingerprint(int version,
-                              String localStableIdentifier, IdentityKey localIdentityKey,
-                              String remoteStableIdentifier, IdentityKey remoteIdentityKey)
-  {
-    this.combinedFingerprint = CombinedFingerprint.newBuilder()
-                                                  .setVersion(version)
-                                                  .setLocalFingerprint(FingerprintData.newBuilder()
-                                                                                      .setIdentifier(ByteString.copyFrom(localStableIdentifier.getBytes()))
-                                                                                      .setPublicKey(ByteString.copyFrom(localIdentityKey.serialize())))
-                                                  .setRemoteFingerprint(FingerprintData.newBuilder()
-                                                                                       .setIdentifier(ByteString.copyFrom(remoteStableIdentifier.getBytes()))
-                                                                                       .setPublicKey(ByteString.copyFrom(remoteIdentityKey.serialize())))
-                                                  .build();
-  }
-
-  /**
-   * @return A byte string to be displayed in a QR code.
-   */
-  public byte[] getSerialized() {
-    return combinedFingerprint.toByteArray();
-  }
-
-  /**
-   * Compare a scanned QR code with what we expect.
-   *
-   * @param scannedFingerprintData The scanned data
-   * @return True if matching, otehrwise false.
-   * @throws FingerprintVersionMismatchException if the scanned fingerprint is the wrong version.
-   * @throws FingerprintIdentifierMismatchException if the scanned fingerprint is for the wrong stable identifier.
-   */
-  public boolean compareTo(byte[] scannedFingerprintData)
-      throws FingerprintVersionMismatchException, FingerprintIdentifierMismatchException
-  {
-    try {
-      CombinedFingerprint scannedFingerprint = CombinedFingerprint.parseFrom(scannedFingerprintData);
-
-      if (!scannedFingerprint.hasRemoteFingerprint() || !scannedFingerprint.hasLocalFingerprint() ||
-          !scannedFingerprint.hasVersion() || scannedFingerprint.getVersion() != combinedFingerprint.getVersion())
-      {
-        throw new FingerprintVersionMismatchException();
-      }
-
-      if (!combinedFingerprint.getLocalFingerprint().getIdentifier().equals(scannedFingerprint.getRemoteFingerprint().getIdentifier()) ||
-          !combinedFingerprint.getRemoteFingerprint().getIdentifier().equals(scannedFingerprint.getLocalFingerprint().getIdentifier()))
-      {
-        throw new FingerprintIdentifierMismatchException(combinedFingerprint.getLocalFingerprint().getIdentifier().toString(),
-                                                         combinedFingerprint.getRemoteFingerprint().getIdentifier().toString(),
-                                                         scannedFingerprint.getLocalFingerprint().getIdentifier().toString(),
-                                                         scannedFingerprint.getRemoteFingerprint().getIdentifier().toString());
-      }
-
-      return MessageDigest.isEqual(combinedFingerprint.getLocalFingerprint().toByteArray(), scannedFingerprint.getRemoteFingerprint().toByteArray()) &&
-             MessageDigest.isEqual(combinedFingerprint.getRemoteFingerprint().toByteArray(), scannedFingerprint.getLocalFingerprint().toByteArray());
-    } catch (InvalidProtocolBufferException e) {
-      throw new FingerprintVersionMismatchException(e);
-    }
-  }
-}

java/src/main/java/org/whispersystems/libaxolotl/groups/SenderKeyName.java

@@ -1,63 +0,0 @@
-/**
- * Copyright (C) 2014-2015 Open Whisper Systems
- *
- * This program is free software: you can redistribute it and/or modify
- * it under the terms of the GNU General Public License as published by
- * the Free Software Foundation, either version 3 of the License, or
- * (at your option) any later version.
- *
- * This program is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
- * GNU General Public License for more details.
- *
- * You should have received a copy of the GNU General Public License
- * along with this program.  If not, see <http://www.gnu.org/licenses/>.
- */
-package org.whispersystems.libaxolotl.groups;
-
-import org.whispersystems.libaxolotl.AxolotlAddress;
-
-/**
- * A representation of a (groupId + senderId + deviceId) tuple.
- */
-public class SenderKeyName {
-
-  private final String         groupId;
-  private final AxolotlAddress sender;
-
-  public SenderKeyName(String groupId, AxolotlAddress sender) {
-    this.groupId  = groupId;
-    this.sender   = sender;
-  }
-
-  public String getGroupId() {
-    return groupId;
-  }
-
-  public AxolotlAddress getSender() {
-    return sender;
-  }
-
-  public String serialize() {
-    return groupId + "::" + sender.getName() + "::" + String.valueOf(sender.getDeviceId());
-  }
-
-  @Override
-  public boolean equals(Object other) {
-    if (other == null)                     return false;
-    if (!(other instanceof SenderKeyName)) return false;
-
-    SenderKeyName that = (SenderKeyName)other;
-
-    return
-        this.groupId.equals(that.groupId) &&
-        this.sender.equals(that.sender);
-  }
-
-  @Override
-  public int hashCode() {
-    return this.groupId.hashCode() ^ this.sender.hashCode();
-  }
-
-}

java/src/main/java/org/whispersystems/libaxolotl/kdf/HKDFv2.java

@@ -1,8 +0,0 @@
-package org.whispersystems.libaxolotl.kdf;
-
-public class HKDFv2 extends HKDF {
-  @Override
-  protected int getIterationStartOffset() {
-    return 0;
-  }
-}

java/src/main/java/org/whispersystems/libaxolotl/kdf/HKDFv3.java

@@ -1,8 +0,0 @@
-package org.whispersystems.libaxolotl.kdf;
-
-public class HKDFv3 extends HKDF {
-  @Override
-  protected int getIterationStartOffset() {
-    return 1;
-  }
-}

java/src/main/java/org/whispersystems/libaxolotl/logging/AxolotlLoggerProvider.java

@@ -1,14 +0,0 @@
-package org.whispersystems.libaxolotl.logging;
-
-public class AxolotlLoggerProvider {
-
-  private static AxolotlLogger provider;
-
-  public static AxolotlLogger getProvider() {
-    return provider;
-  }
-
-  public static void setProvider(AxolotlLogger provider) {
-    AxolotlLoggerProvider.provider = provider;
-  }
-}

java/src/main/java/org/whispersystems/libaxolotl/protocol/CiphertextMessage.java

@@ -1,35 +0,0 @@
-/**
- * Copyright (C) 2014 Open Whisper Systems
- *
- * This program is free software: you can redistribute it and/or modify
- * it under the terms of the GNU General Public License as published by
- * the Free Software Foundation, either version 3 of the License, or
- * (at your option) any later version.
- *
- * This program is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
- * GNU General Public License for more details.
- *
- * You should have received a copy of the GNU General Public License
- * along with this program.  If not, see <http://www.gnu.org/licenses/>.
- */
-package org.whispersystems.libaxolotl.protocol;
-
-public interface CiphertextMessage {
-
-  public static final int UNSUPPORTED_VERSION = 1;
-  public static final int CURRENT_VERSION     = 3;
-
-  public static final int WHISPER_TYPE                = 2;
-  public static final int PREKEY_TYPE                 = 3;
-  public static final int SENDERKEY_TYPE              = 4;
-  public static final int SENDERKEY_DISTRIBUTION_TYPE = 5;
-
-  // This should be the worst case (worse than V2).  So not always accurate, but good enough for padding.
-  public static final int ENCRYPTED_MESSAGE_OVERHEAD = 53;
-
-  public byte[] serialize();
-  public int getType();
-
-}

java/src/main/java/org/whispersystems/libaxolotl/protocol/KeyExchangeMessage.java

@@ -1,153 +0,0 @@
-package org.whispersystems.libaxolotl.protocol;
-
-
-import com.google.protobuf.ByteString;
-
-import org.whispersystems.libaxolotl.IdentityKey;
-import org.whispersystems.libaxolotl.InvalidKeyException;
-import org.whispersystems.libaxolotl.InvalidMessageException;
-import org.whispersystems.libaxolotl.InvalidVersionException;
-import org.whispersystems.libaxolotl.LegacyMessageException;
-import org.whispersystems.libaxolotl.ecc.Curve;
-import org.whispersystems.libaxolotl.ecc.ECPublicKey;
-import org.whispersystems.libaxolotl.util.ByteUtil;
-
-import java.io.IOException;
-
-import static org.whispersystems.libaxolotl.protocol.WhisperProtos.KeyExchangeMessage.Builder;
-
-public class KeyExchangeMessage {
-
-  public static final int INITIATE_FLAG              = 0x01;
-  public static final int RESPONSE_FLAG              = 0X02;
-  public static final int SIMULTAENOUS_INITIATE_FLAG = 0x04;
-
-  private final int         version;
-  private final int         supportedVersion;
-  private final int         sequence;
-  private final int         flags;
-
-  private final ECPublicKey baseKey;
-  private final byte[]      baseKeySignature;
-  private final ECPublicKey ratchetKey;
-  private final IdentityKey identityKey;
-  private final byte[]      serialized;
-
-  public KeyExchangeMessage(int messageVersion, int sequence, int flags,
-                            ECPublicKey baseKey, byte[] baseKeySignature,
-                            ECPublicKey ratchetKey,
-                            IdentityKey identityKey)
-  {
-    this.supportedVersion = CiphertextMessage.CURRENT_VERSION;
-    this.version          = messageVersion;
-    this.sequence         = sequence;
-    this.flags            = flags;
-    this.baseKey          = baseKey;
-    this.baseKeySignature = baseKeySignature;
-    this.ratchetKey       = ratchetKey;
-    this.identityKey      = identityKey;
-
-    byte[]  version = {ByteUtil.intsToByteHighAndLow(this.version, this.supportedVersion)};
-    Builder builder = WhisperProtos.KeyExchangeMessage
-                                   .newBuilder()
-                                   .setId((sequence << 5) | flags)
-                                   .setBaseKey(ByteString.copyFrom(baseKey.serialize()))
-                                   .setRatchetKey(ByteString.copyFrom(ratchetKey.serialize()))
-                                   .setIdentityKey(ByteString.copyFrom(identityKey.serialize()));
-
-    if (messageVersion >= 3) {
-      builder.setBaseKeySignature(ByteString.copyFrom(baseKeySignature));
-    }
-
-    this.serialized = ByteUtil.combine(version, builder.build().toByteArray());
-  }
-
-  public KeyExchangeMessage(byte[] serialized)
-      throws InvalidMessageException, InvalidVersionException, LegacyMessageException
-  {
-    try {
-      byte[][] parts        = ByteUtil.split(serialized, 1, serialized.length - 1);
-      this.version          = ByteUtil.highBitsToInt(parts[0][0]);
-      this.supportedVersion = ByteUtil.lowBitsToInt(parts[0][0]);
-
-      if (this.version <= CiphertextMessage.UNSUPPORTED_VERSION) {
-        throw new LegacyMessageException("Unsupported legacy version: " + this.version);
-      }
-
-      if (this.version > CiphertextMessage.CURRENT_VERSION) {
-        throw new InvalidVersionException("Unknown version: " + this.version);
-      }
-
-      WhisperProtos.KeyExchangeMessage message = WhisperProtos.KeyExchangeMessage.parseFrom(parts[1]);
-
-      if (!message.hasId()           || !message.hasBaseKey()     ||
-          !message.hasRatchetKey()   || !message.hasIdentityKey() ||
-          (this.version >=3 && !message.hasBaseKeySignature()))
-      {
-        throw new InvalidMessageException("Some required fields missing!");
-      }
-
-      this.sequence         = message.getId() >> 5;
-      this.flags            = message.getId() & 0x1f;
-      this.serialized       = serialized;
-      this.baseKey          = Curve.decodePoint(message.getBaseKey().toByteArray(), 0);
-      this.baseKeySignature = message.getBaseKeySignature().toByteArray();
-      this.ratchetKey       = Curve.decodePoint(message.getRatchetKey().toByteArray(), 0);
-      this.identityKey      = new IdentityKey(message.getIdentityKey().toByteArray(), 0);
-    } catch (InvalidKeyException | IOException e) {
-      throw new InvalidMessageException(e);
-    }
-  }
-
-  public int getVersion() {
-    return version;
-  }
-
-  public ECPublicKey getBaseKey() {
-    return baseKey;
-  }
-
-  public byte[] getBaseKeySignature() {
-    return baseKeySignature;
-  }
-
-  public ECPublicKey getRatchetKey() {
-    return ratchetKey;
-  }
-
-  public IdentityKey getIdentityKey() {
-    return identityKey;
-  }
-
-  public boolean hasIdentityKey() {
-    return true;
-  }
-
-  public int getMaxVersion() {
-    return supportedVersion;
-  }
-
-  public boolean isResponse() {
-    return ((flags & RESPONSE_FLAG) != 0);
-  }
-
-  public boolean isInitiate() {
-    return (flags & INITIATE_FLAG) != 0;
-  }
-
-  public boolean isResponseForSimultaneousInitiate() {
-    return (flags & SIMULTAENOUS_INITIATE_FLAG) != 0;
-  }
-
-  public int getFlags() {
-    return flags;
-  }
-
-  public int getSequence() {
-    return sequence;
-  }
-
-  public byte[] serialize() {
-    return serialized;
-  }
-}

java/src/main/java/org/whispersystems/libaxolotl/protocol/PreKeyWhisperMessage.java

@@ -1,147 +0,0 @@
-/**
- * Copyright (C) 2014 Open Whisper Systems
- *
- * This program is free software: you can redistribute it and/or modify
- * it under the terms of the GNU General Public License as published by
- * the Free Software Foundation, either version 3 of the License, or
- * (at your option) any later version.
- *
- * This program is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
- * GNU General Public License for more details.
- *
- * You should have received a copy of the GNU General Public License
- * along with this program.  If not, see <http://www.gnu.org/licenses/>.
- */
-package org.whispersystems.libaxolotl.protocol;
-
-import com.google.protobuf.ByteString;
-import com.google.protobuf.InvalidProtocolBufferException;
-
-import org.whispersystems.libaxolotl.IdentityKey;
-import org.whispersystems.libaxolotl.InvalidKeyException;
-import org.whispersystems.libaxolotl.InvalidMessageException;
-import org.whispersystems.libaxolotl.InvalidVersionException;
-import org.whispersystems.libaxolotl.LegacyMessageException;
-import org.whispersystems.libaxolotl.ecc.Curve;
-import org.whispersystems.libaxolotl.ecc.ECPublicKey;
-import org.whispersystems.libaxolotl.util.ByteUtil;
-import org.whispersystems.libaxolotl.util.guava.Optional;
-
-
-public class PreKeyWhisperMessage implements CiphertextMessage {
-
-  private final int               version;
-  private final int               registrationId;
-  private final Optional<Integer> preKeyId;
-  private final int               signedPreKeyId;
-  private final ECPublicKey       baseKey;
-  private final IdentityKey       identityKey;
-  private final WhisperMessage    message;
-  private final byte[]            serialized;
-
-  public PreKeyWhisperMessage(byte[] serialized)
-      throws InvalidMessageException, InvalidVersionException
-  {
-    try {
-      this.version = ByteUtil.highBitsToInt(serialized[0]);
-
-      if (this.version > CiphertextMessage.CURRENT_VERSION) {
-        throw new InvalidVersionException("Unknown version: " + this.version);
-      }
-
-      WhisperProtos.PreKeyWhisperMessage preKeyWhisperMessage
-          = WhisperProtos.PreKeyWhisperMessage.parseFrom(ByteString.copyFrom(serialized, 1,
-                                                                             serialized.length-1));
-
-      if ((version == 2 && !preKeyWhisperMessage.hasPreKeyId())        ||
-          (version == 3 && !preKeyWhisperMessage.hasSignedPreKeyId())  ||
-          !preKeyWhisperMessage.hasBaseKey()                           ||
-          !preKeyWhisperMessage.hasIdentityKey()                       ||
-          !preKeyWhisperMessage.hasMessage())
-      {
-        throw new InvalidMessageException("Incomplete message.");
-      }
-
-      this.serialized     = serialized;
-      this.registrationId = preKeyWhisperMessage.getRegistrationId();
-      this.preKeyId       = preKeyWhisperMessage.hasPreKeyId() ? Optional.of(preKeyWhisperMessage.getPreKeyId()) : Optional.<Integer>absent();
-      this.signedPreKeyId = preKeyWhisperMessage.hasSignedPreKeyId() ? preKeyWhisperMessage.getSignedPreKeyId() : -1;
-      this.baseKey        = Curve.decodePoint(preKeyWhisperMessage.getBaseKey().toByteArray(), 0);
-      this.identityKey    = new IdentityKey(Curve.decodePoint(preKeyWhisperMessage.getIdentityKey().toByteArray(), 0));
-      this.message        = new WhisperMessage(preKeyWhisperMessage.getMessage().toByteArray());
-    } catch (InvalidProtocolBufferException | InvalidKeyException | LegacyMessageException e) {
-      throw new InvalidMessageException(e);
-    }
-  }
-
-  public PreKeyWhisperMessage(int messageVersion, int registrationId, Optional<Integer> preKeyId,
-                              int signedPreKeyId, ECPublicKey baseKey, IdentityKey identityKey,
-                              WhisperMessage message)
-  {
-    this.version        = messageVersion;
-    this.registrationId = registrationId;
-    this.preKeyId       = preKeyId;
-    this.signedPreKeyId = signedPreKeyId;
-    this.baseKey        = baseKey;
-    this.identityKey    = identityKey;
-    this.message        = message;
-
-    WhisperProtos.PreKeyWhisperMessage.Builder builder =
-        WhisperProtos.PreKeyWhisperMessage.newBuilder()
-                                          .setSignedPreKeyId(signedPreKeyId)
-                                          .setBaseKey(ByteString.copyFrom(baseKey.serialize()))
-                                          .setIdentityKey(ByteString.copyFrom(identityKey.serialize()))
-                                          .setMessage(ByteString.copyFrom(message.serialize()))
-                                          .setRegistrationId(registrationId);
-
-    if (preKeyId.isPresent()) {
-      builder.setPreKeyId(preKeyId.get());
-    }
-
-    byte[] versionBytes = {ByteUtil.intsToByteHighAndLow(this.version, CURRENT_VERSION)};
-    byte[] messageBytes = builder.build().toByteArray();
-
-    this.serialized = ByteUtil.combine(versionBytes, messageBytes);
-  }
-
-  public int getMessageVersion() {
-    return version;
-  }
-
-  public IdentityKey getIdentityKey() {
-    return identityKey;
-  }
-
-  public int getRegistrationId() {
-    return registrationId;
-  }
-
-  public Optional<Integer> getPreKeyId() {
-    return preKeyId;
-  }
-
-  public int getSignedPreKeyId() {
-    return signedPreKeyId;
-  }
-
-  public ECPublicKey getBaseKey() {
-    return baseKey;
-  }
-
-  public WhisperMessage getWhisperMessage() {
-    return message;
-  }
-
-  @Override
-  public byte[] serialize() {
-    return serialized;
-  }
-
-  @Override
-  public int getType() {
-    return CiphertextMessage.PREKEY_TYPE;
-  }
-
-}

java/src/main/java/org/whispersystems/libaxolotl/ratchet/RootKey.java

@@ -1,54 +0,0 @@
-/**
- * Copyright (C) 2014 Open Whisper Systems
- *
- * This program is free software: you can redistribute it and/or modify
- * it under the terms of the GNU General Public License as published by
- * the Free Software Foundation, either version 3 of the License, or
- * (at your option) any later version.
- *
- * This program is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
- * GNU General Public License for more details.
- *
- * You should have received a copy of the GNU General Public License
- * along with this program.  If not, see <http://www.gnu.org/licenses/>.
- */
-package org.whispersystems.libaxolotl.ratchet;
-
-import org.whispersystems.libaxolotl.InvalidKeyException;
-import org.whispersystems.libaxolotl.ecc.Curve;
-import org.whispersystems.libaxolotl.ecc.ECKeyPair;
-import org.whispersystems.libaxolotl.ecc.ECPublicKey;
-import org.whispersystems.libaxolotl.kdf.DerivedRootSecrets;
-import org.whispersystems.libaxolotl.kdf.HKDF;
-import org.whispersystems.libaxolotl.util.ByteUtil;
-import org.whispersystems.libaxolotl.util.Pair;
-
-public class RootKey {
-
-  private final HKDF   kdf;
-  private final byte[] key;
-
-  public RootKey(HKDF kdf, byte[] key) {
-    this.kdf = kdf;
-    this.key = key;
-  }
-
-  public byte[] getKeyBytes() {
-    return key;
-  }
-
-  public Pair<RootKey, ChainKey> createChain(ECPublicKey theirRatchetKey, ECKeyPair ourRatchetKey)
-      throws InvalidKeyException
-  {
-    byte[]             sharedSecret       = Curve.calculateAgreement(theirRatchetKey, ourRatchetKey.getPrivateKey());
-    byte[]             derivedSecretBytes = kdf.deriveSecrets(sharedSecret, key, "WhisperRatchet".getBytes(), DerivedRootSecrets.SIZE);
-    DerivedRootSecrets derivedSecrets     = new DerivedRootSecrets(derivedSecretBytes);
-
-    RootKey  newRootKey  = new RootKey(kdf, derivedSecrets.getRootKey());
-    ChainKey newChainKey = new ChainKey(kdf, derivedSecrets.getChainKey(), 0);
-
-    return new Pair<>(newRootKey, newChainKey);
-  }
-}

java/src/main/java/org/whispersystems/libaxolotl/state/AxolotlStore.java

@@ -1,6 +0,0 @@
-package org.whispersystems.libaxolotl.state;
-
-public interface AxolotlStore
-    extends IdentityKeyStore, PreKeyStore, SessionStore, SignedPreKeyStore
-{
-}

java/src/main/java/org/whispersystems/libaxolotl/state/IdentityKeyStore.java

@@ -1,57 +0,0 @@
-package org.whispersystems.libaxolotl.state;
-
-import org.whispersystems.libaxolotl.IdentityKey;
-import org.whispersystems.libaxolotl.IdentityKeyPair;
-
-/**
- * Provides an interface to identity information.
- *
- * @author Moxie Marlinspike
- */
-public interface IdentityKeyStore {
-
-  /**
-   * Get the local client's identity key pair.
-   *
-   * @return The local client's persistent identity key pair.
-   */
-  public IdentityKeyPair getIdentityKeyPair();
-
-  /**
-   * Return the local client's registration ID.
-   * <p>
-   * Clients should maintain a registration ID, a random number
-   * between 1 and 16380 that's generated once at install time.
-   *
-   * @return the local client's registration ID.
-   */
-  public int             getLocalRegistrationId();
-
-  /**
-   * Save a remote client's identity key
-   * <p>
-   * Store a remote client's identity key as trusted.
-   *
-   * @param name        The name of the remote client.
-   * @param identityKey The remote client's identity key.
-   */
-  public void            saveIdentity(String name, IdentityKey identityKey);
-
-
-  /**
-   * Verify a remote client's identity key.
-   * <p>
-   * Determine whether a remote client's identity is trusted.  Convention is
-   * that the TextSecure protocol is 'trust on first use.'  This means that
-   * an identity key is considered 'trusted' if there is no entry for the recipient
-   * in the local store, or if it matches the saved key for a recipient in the local
-   * store.  Only if it mismatches an entry in the local store is it considered
-   * 'untrusted.'
-   *
-   * @param name        The name of the remote client.
-   * @param identityKey The identity key to verify.
-   * @return true if trusted, false if untrusted.
-   */
-  public boolean         isTrustedIdentity(String name, IdentityKey identityKey);
-
-}

java/src/main/java/org/whispersystems/libaxolotl/state/impl/InMemoryIdentityKeyStore.java

@@ -1,46 +0,0 @@
-package org.whispersystems.libaxolotl.state.impl;
-
-import org.whispersystems.libaxolotl.IdentityKey;
-import org.whispersystems.libaxolotl.IdentityKeyPair;
-import org.whispersystems.libaxolotl.ecc.Curve;
-import org.whispersystems.libaxolotl.ecc.ECKeyPair;
-import org.whispersystems.libaxolotl.state.IdentityKeyStore;
-
-import java.security.NoSuchAlgorithmException;
-import java.security.SecureRandom;
-import java.util.HashMap;
-import java.util.Map;
-
-public class InMemoryIdentityKeyStore implements IdentityKeyStore {
-
-  private final Map<String, IdentityKey> trustedKeys = new HashMap<>();
-
-  private final IdentityKeyPair identityKeyPair;
-  private final int             localRegistrationId;
-
-  public InMemoryIdentityKeyStore(IdentityKeyPair identityKeyPair, int localRegistrationId) {
-    this.identityKeyPair     = identityKeyPair;
-    this.localRegistrationId = localRegistrationId;
-  }
-
-  @Override
-  public IdentityKeyPair getIdentityKeyPair() {
-    return identityKeyPair;
-  }
-
-  @Override
-  public int getLocalRegistrationId() {
-    return localRegistrationId;
-  }
-
-  @Override
-  public void saveIdentity(String name, IdentityKey identityKey) {
-    trustedKeys.put(name, identityKey);
-  }
-
-  @Override
-  public boolean isTrustedIdentity(String name, IdentityKey identityKey) {
-    IdentityKey trusted = trustedKeys.get(name);
-    return (trusted == null || trusted.equals(identityKey));
-  }
-}

java/src/main/java/org/whispersystems/libaxolotl/util/Medium.java

@@ -1,5 +0,0 @@
-package org.whispersystems.libaxolotl.util;
-
-public class Medium {
-  public static int MAX_VALUE = 0xFFFFFF;
-}

java/src/main/java/org/whispersystems/libaxolotl/util/Pair.java

@@ -1,51 +0,0 @@
-/**
- * Copyright (C) 2014 Open WhisperSystems
- *
- * This program is free software: you can redistribute it and/or modify
- * it under the terms of the GNU Affero General Public License as published by
- * the Free Software Foundation, either version 3 of the License, or
- * (at your option) any later version.
- *
- * This program is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
- * GNU Affero General Public License for more details.
- *
- * You should have received a copy of the GNU Affero General Public License
- * along with this program.  If not, see <http://www.gnu.org/licenses/>.
- */
-package org.whispersystems.libaxolotl.util;
-
-public class Pair<T1, T2> {
-  private final T1 v1;
-  private final T2 v2;
-
-  public Pair(T1 v1, T2 v2) {
-    this.v1 = v1;
-    this.v2 = v2;
-  }
-
-  public T1 first(){
-    return v1;
-  }
-
-  public T2 second(){
-    return v2;
-  }
-
-  public boolean equals(Object o) {
-    return o instanceof Pair &&
-        equal(((Pair) o).first(), first()) &&
-        equal(((Pair) o).second(), second());
-  }
-
-  public int hashCode() {
-    return first().hashCode() ^ second().hashCode();
-  }
-
-  private boolean equal(Object first, Object second) {
-    if (first == null && second == null) return true;
-    if (first == null || second == null) return false;
-    return first.equals(second);
-  }
-}

java/src/main/java/org/whispersystems/libsignal/DecryptionCallback.java

@@ -0,0 +1,10 @@
+/**
+ * Copyright (C) 2014-2016 Open Whisper Systems
+ *
+ * Licensed according to the LICENSE file in this repository.
+ */
+package org.whispersystems.libsignal;
+
+public interface DecryptionCallback {
+  public void handlePlaintext(byte[] plaintext);
+}

java/src/main/java/org/whispersystems/libsignal/DuplicateMessageException.java

@@ -0,0 +1,12 @@
+/**
+ * Copyright (C) 2014-2016 Open Whisper Systems
+ *
+ * Licensed according to the LICENSE file in this repository.
+ */
+package org.whispersystems.libsignal;
+
+public class DuplicateMessageException extends Exception {
+  public DuplicateMessageException(String s) {
+    super(s);
+  }
+}

java/src/main/java/org/whispersystems/libsignal/IdentityKey.java

@@ -1,25 +1,14 @@
-/** 
- * Copyright (C) 2014 Open Whisper Systems
- * 
- * This program is free software: you can redistribute it and/or modify
- * it under the terms of the GNU General Public License as published by
- * the Free Software Foundation, either version 3 of the License, or
- * (at your option) any later version.
+/**
+ * Copyright (C) 2014-2016 Open Whisper Systems
  *
- * This program is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
- * GNU General Public License for more details.
- * 
- * You should have received a copy of the GNU General Public License
- * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ * Licensed according to the LICENSE file in this repository.
  */
-package org.whispersystems.libaxolotl;
+package org.whispersystems.libsignal;
 
 
-import org.whispersystems.libaxolotl.ecc.Curve;
-import org.whispersystems.libaxolotl.ecc.ECPublicKey;
-import org.whispersystems.libaxolotl.util.Hex;
+import org.whispersystems.libsignal.ecc.Curve;
+import org.whispersystems.libsignal.ecc.ECPublicKey;
+import org.whispersystems.libsignal.util.Hex;
 
 /**
  * A class for representing an identity key.

java/src/main/java/org/whispersystems/libsignal/IdentityKeyPair.java

@@ -1,28 +1,17 @@
 /**
- * Copyright (C) 2013 Open Whisper Systems
+ * Copyright (C) 2014-2016 Open Whisper Systems
  *
- * This program is free software: you can redistribute it and/or modify
- * it under the terms of the GNU General Public License as published by
- * the Free Software Foundation, either version 3 of the License, or
- * (at your option) any later version.
- *
- * This program is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
- * GNU General Public License for more details.
- *
- * You should have received a copy of the GNU General Public License
- * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ * Licensed according to the LICENSE file in this repository.
  */
-package org.whispersystems.libaxolotl;
+package org.whispersystems.libsignal;
 
 import com.google.protobuf.ByteString;
 import com.google.protobuf.InvalidProtocolBufferException;
 
-import org.whispersystems.libaxolotl.ecc.Curve;
-import org.whispersystems.libaxolotl.ecc.ECPrivateKey;
+import org.whispersystems.libsignal.ecc.Curve;
+import org.whispersystems.libsignal.ecc.ECPrivateKey;
 
-import static org.whispersystems.libaxolotl.state.StorageProtos.IdentityKeyPairStructure;
+import static org.whispersystems.libsignal.state.StorageProtos.IdentityKeyPairStructure;
 
 /**
  * Holder for public and private identity key pair.

java/src/main/java/org/whispersystems/libsignal/InvalidKeyException.java

@@ -0,0 +1,23 @@
+/**
+ * Copyright (C) 2014-2016 Open Whisper Systems
+ *
+ * Licensed according to the LICENSE file in this repository.
+ */
+package org.whispersystems.libsignal;
+
+public class InvalidKeyException extends Exception {
+
+  public InvalidKeyException() {}
+
+  public InvalidKeyException(String detailMessage) {
+    super(detailMessage);
+  }
+
+  public InvalidKeyException(Throwable throwable) {
+    super(throwable);
+  }
+
+  public InvalidKeyException(String detailMessage, Throwable throwable) {
+    super(detailMessage, throwable);
+  }
+}

java/src/main/java/org/whispersystems/libsignal/InvalidKeyIdException.java

@@ -0,0 +1,16 @@
+/**
+ * Copyright (C) 2014-2016 Open Whisper Systems
+ *
+ * Licensed according to the LICENSE file in this repository.
+ */
+package org.whispersystems.libsignal;
+
+public class InvalidKeyIdException extends Exception {
+  public InvalidKeyIdException(String detailMessage) {
+    super(detailMessage);
+  }
+
+  public InvalidKeyIdException(Throwable throwable) {
+    super(throwable);
+  }
+}

java/src/main/java/org/whispersystems/libsignal/InvalidMacException.java

@@ -0,0 +1,17 @@
+/**
+ * Copyright (C) 2014-2016 Open Whisper Systems
+ *
+ * Licensed according to the LICENSE file in this repository.
+ */
+package org.whispersystems.libsignal;
+
+public class InvalidMacException extends Exception {
+
+  public InvalidMacException(String detailMessage) {
+    super(detailMessage);
+  }
+
+  public InvalidMacException(Throwable throwable) {
+    super(throwable);
+  }
+}

java/src/main/java/org/whispersystems/libsignal/InvalidMessageException.java

@@ -0,0 +1,29 @@
+/**
+ * Copyright (C) 2014-2016 Open Whisper Systems
+ *
+ * Licensed according to the LICENSE file in this repository.
+ */
+package org.whispersystems.libsignal;
+
+import java.util.List;
+
+public class InvalidMessageException extends Exception {
+
+  public InvalidMessageException() {}
+
+  public InvalidMessageException(String detailMessage) {
+    super(detailMessage);
+  }
+
+  public InvalidMessageException(Throwable throwable) {
+    super(throwable);
+  }
+
+  public InvalidMessageException(String detailMessage, Throwable throwable) {
+    super(detailMessage, throwable);
+  }
+
+  public InvalidMessageException(String detailMessage, List<Exception> exceptions) {
+    super(detailMessage, exceptions.get(0));
+  }
+}

java/src/main/java/org/whispersystems/libsignal/InvalidVersionException.java

@@ -0,0 +1,12 @@
+/**
+ * Copyright (C) 2014-2016 Open Whisper Systems
+ *
+ * Licensed according to the LICENSE file in this repository.
+ */
+package org.whispersystems.libsignal;
+
+public class InvalidVersionException extends Exception {
+  public InvalidVersionException(String detailMessage) {
+    super(detailMessage);
+  }
+}

java/src/main/java/org/whispersystems/libsignal/LegacyMessageException.java

@@ -0,0 +1,12 @@
+/**
+ * Copyright (C) 2014-2016 Open Whisper Systems
+ *
+ * Licensed according to the LICENSE file in this repository.
+ */
+package org.whispersystems.libsignal;
+
+public class LegacyMessageException extends Exception {
+  public LegacyMessageException(String s) {
+    super(s);
+  }
+}

java/src/main/java/org/whispersystems/libsignal/NoSessionException.java

@@ -1,4 +1,9 @@
-package org.whispersystems.libaxolotl;
+/**
+ * Copyright (C) 2014-2016 Open Whisper Systems
+ *
+ * Licensed according to the LICENSE file in this repository.
+ */
+package org.whispersystems.libsignal;
 
 public class NoSessionException extends Exception {
   public NoSessionException(String s) {

java/src/main/java/org/whispersystems/libsignal/SessionBuilder.java

@@ -0,0 +1,213 @@
+/**
+ * Copyright (C) 2014-2016 Open Whisper Systems
+ *
+ * Licensed according to the LICENSE file in this repository.
+ */
+package org.whispersystems.libsignal;
+
+
+import org.whispersystems.libsignal.ecc.Curve;
+import org.whispersystems.libsignal.ecc.ECKeyPair;
+import org.whispersystems.libsignal.ecc.ECPublicKey;
+import org.whispersystems.libsignal.logging.Log;
+import org.whispersystems.libsignal.protocol.PreKeySignalMessage;
+import org.whispersystems.libsignal.protocol.SignalMessage;
+import org.whispersystems.libsignal.ratchet.AliceSignalProtocolParameters;
+import org.whispersystems.libsignal.ratchet.BobSignalProtocolParameters;
+import org.whispersystems.libsignal.ratchet.RatchetingSession;
+import org.whispersystems.libsignal.state.IdentityKeyStore;
+import org.whispersystems.libsignal.state.PreKeyBundle;
+import org.whispersystems.libsignal.state.PreKeyStore;
+import org.whispersystems.libsignal.state.SessionRecord;
+import org.whispersystems.libsignal.state.SessionStore;
+import org.whispersystems.libsignal.state.SignalProtocolStore;
+import org.whispersystems.libsignal.state.SignedPreKeyStore;
+import org.whispersystems.libsignal.util.Medium;
+import org.whispersystems.libsignal.util.guava.Optional;
+
+/**
+ * SessionBuilder is responsible for setting up encrypted sessions.
+ * Once a session has been established, {@link org.whispersystems.libsignal.SessionCipher}
+ * can be used to encrypt/decrypt messages in that session.
+ * <p>
+ * Sessions are built from one of three different possible vectors:
+ * <ol>
+ *   <li>A {@link org.whispersystems.libsignal.state.PreKeyBundle} retrieved from a server.</li>
+ *   <li>A {@link PreKeySignalMessage} received from a client.</li>
+ * </ol>
+ *
+ * Sessions are constructed per recipientId + deviceId tuple.  Remote logical users are identified
+ * by their recipientId, and each logical recipientId can have multiple physical devices.
+ *
+ * @author Moxie Marlinspike
+ */
+public class SessionBuilder {
+
+  private static final String TAG = SessionBuilder.class.getSimpleName();
+
+  private final SessionStore      sessionStore;
+  private final PreKeyStore       preKeyStore;
+  private final SignedPreKeyStore signedPreKeyStore;
+  private final IdentityKeyStore  identityKeyStore;
+  private final SignalProtocolAddress remoteAddress;
+
+  /**
+   * Constructs a SessionBuilder.
+   *
+   * @param sessionStore The {@link org.whispersystems.libsignal.state.SessionStore} to store the constructed session in.
+   * @param preKeyStore The {@link  org.whispersystems.libsignal.state.PreKeyStore} where the client's local {@link org.whispersystems.libsignal.state.PreKeyRecord}s are stored.
+   * @param identityKeyStore The {@link org.whispersystems.libsignal.state.IdentityKeyStore} containing the client's identity key information.
+   * @param remoteAddress The address of the remote user to build a session with.
+   */
+  public SessionBuilder(SessionStore sessionStore,
+                        PreKeyStore preKeyStore,
+                        SignedPreKeyStore signedPreKeyStore,
+                        IdentityKeyStore identityKeyStore,
+                        SignalProtocolAddress remoteAddress)
+  {
+    this.sessionStore      = sessionStore;
+    this.preKeyStore       = preKeyStore;
+    this.signedPreKeyStore = signedPreKeyStore;
+    this.identityKeyStore  = identityKeyStore;
+    this.remoteAddress     = remoteAddress;
+  }
+
+  /**
+   * Constructs a SessionBuilder
+   * @param store The {@link SignalProtocolStore} to store all state information in.
+   * @param remoteAddress The address of the remote user to build a session with.
+   */
+  public SessionBuilder(SignalProtocolStore store, SignalProtocolAddress remoteAddress) {
+    this(store, store, store, store, remoteAddress);
+  }
+
+  /**
+   * Build a new session from a received {@link PreKeySignalMessage}.
+   *
+   * After a session is constructed in this way, the embedded {@link SignalMessage}
+   * can be decrypted.
+   *
+   * @param message The received {@link PreKeySignalMessage}.
+   * @throws org.whispersystems.libsignal.InvalidKeyIdException when there is no local
+   *                                                             {@link org.whispersystems.libsignal.state.PreKeyRecord}
+   *                                                             that corresponds to the PreKey ID in
+   *                                                             the message.
+   * @throws org.whispersystems.libsignal.InvalidKeyException when the message is formatted incorrectly.
+   * @throws org.whispersystems.libsignal.UntrustedIdentityException when the {@link IdentityKey} of the sender is untrusted.
+   */
+  /*package*/ Optional<Integer> process(SessionRecord sessionRecord, PreKeySignalMessage message)
+      throws InvalidKeyIdException, InvalidKeyException, UntrustedIdentityException
+  {
+    IdentityKey theirIdentityKey = message.getIdentityKey();
+
+    if (!identityKeyStore.isTrustedIdentity(remoteAddress, theirIdentityKey, IdentityKeyStore.Direction.RECEIVING)) {
+      throw new UntrustedIdentityException(remoteAddress.getName(), theirIdentityKey);
+    }
+
+    Optional<Integer> unsignedPreKeyId = processV3(sessionRecord, message);
+
+    identityKeyStore.saveIdentity(remoteAddress, theirIdentityKey);
+
+    return unsignedPreKeyId;
+  }
+
+  private Optional<Integer> processV3(SessionRecord sessionRecord, PreKeySignalMessage message)
+      throws UntrustedIdentityException, InvalidKeyIdException, InvalidKeyException
+  {
+
+    if (sessionRecord.hasSessionState(message.getMessageVersion(), message.getBaseKey().serialize())) {
+      Log.w(TAG, "We've already setup a session for this V3 message, letting bundled message fall through...");
+      return Optional.absent();
+    }
+
+    ECKeyPair ourSignedPreKey = signedPreKeyStore.loadSignedPreKey(message.getSignedPreKeyId()).getKeyPair();
+
+    BobSignalProtocolParameters.Builder parameters = BobSignalProtocolParameters.newBuilder();
+
+    parameters.setTheirBaseKey(message.getBaseKey())
+              .setTheirIdentityKey(message.getIdentityKey())
+              .setOurIdentityKey(identityKeyStore.getIdentityKeyPair())
+              .setOurSignedPreKey(ourSignedPreKey)
+              .setOurRatchetKey(ourSignedPreKey);
+
+    if (message.getPreKeyId().isPresent()) {
+      parameters.setOurOneTimePreKey(Optional.of(preKeyStore.loadPreKey(message.getPreKeyId().get()).getKeyPair()));
+    } else {
+      parameters.setOurOneTimePreKey(Optional.<ECKeyPair>absent());
+    }
+
+    if (!sessionRecord.isFresh()) sessionRecord.archiveCurrentState();
+
+    RatchetingSession.initializeSession(sessionRecord.getSessionState(), parameters.create());
+
+    sessionRecord.getSessionState().setLocalRegistrationId(identityKeyStore.getLocalRegistrationId());
+    sessionRecord.getSessionState().setRemoteRegistrationId(message.getRegistrationId());
+    sessionRecord.getSessionState().setAliceBaseKey(message.getBaseKey().serialize());
+
+    if (message.getPreKeyId().isPresent()) {
+      return message.getPreKeyId();
+    } else {
+      return Optional.absent();
+    }
+  }
+
+  /**
+   * Build a new session from a {@link org.whispersystems.libsignal.state.PreKeyBundle} retrieved from
+   * a server.
+   *
+   * @param preKey A PreKey for the destination recipient, retrieved from a server.
+   * @throws InvalidKeyException when the {@link org.whispersystems.libsignal.state.PreKeyBundle} is
+   *                             badly formatted.
+   * @throws org.whispersystems.libsignal.UntrustedIdentityException when the sender's
+   *                                                                  {@link IdentityKey} is not
+   *                                                                  trusted.
+   */
+  public void process(PreKeyBundle preKey) throws InvalidKeyException, UntrustedIdentityException {
+    synchronized (SessionCipher.SESSION_LOCK) {
+      if (!identityKeyStore.isTrustedIdentity(remoteAddress, preKey.getIdentityKey(), IdentityKeyStore.Direction.SENDING)) {
+        throw new UntrustedIdentityException(remoteAddress.getName(), preKey.getIdentityKey());
+      }
+
+      if (preKey.getSignedPreKey() != null &&
+          !Curve.verifySignature(preKey.getIdentityKey().getPublicKey(),
+                                 preKey.getSignedPreKey().serialize(),
+                                 preKey.getSignedPreKeySignature()))
+      {
+        throw new InvalidKeyException("Invalid signature on device key!");
+      }
+
+      if (preKey.getSignedPreKey() == null) {
+        throw new InvalidKeyException("No signed prekey!");
+      }
+
+      SessionRecord         sessionRecord        = sessionStore.loadSession(remoteAddress);
+      ECKeyPair             ourBaseKey           = Curve.generateKeyPair();
+      ECPublicKey           theirSignedPreKey    = preKey.getSignedPreKey();
+      Optional<ECPublicKey> theirOneTimePreKey   = Optional.fromNullable(preKey.getPreKey());
+      Optional<Integer>     theirOneTimePreKeyId = theirOneTimePreKey.isPresent() ? Optional.of(preKey.getPreKeyId()) :
+                                                                                    Optional.<Integer>absent();
+
+      AliceSignalProtocolParameters.Builder parameters = AliceSignalProtocolParameters.newBuilder();
+
+      parameters.setOurBaseKey(ourBaseKey)
+                .setOurIdentityKey(identityKeyStore.getIdentityKeyPair())
+                .setTheirIdentityKey(preKey.getIdentityKey())
+                .setTheirSignedPreKey(theirSignedPreKey)
+                .setTheirRatchetKey(theirSignedPreKey)
+                .setTheirOneTimePreKey(theirOneTimePreKey);
+
+      if (!sessionRecord.isFresh()) sessionRecord.archiveCurrentState();
+
+      RatchetingSession.initializeSession(sessionRecord.getSessionState(), parameters.create());
+
+      sessionRecord.getSessionState().setUnacknowledgedPreKeyMessage(theirOneTimePreKeyId, preKey.getSignedPreKeyId(), ourBaseKey.getPublicKey());
+      sessionRecord.getSessionState().setLocalRegistrationId(identityKeyStore.getLocalRegistrationId());
+      sessionRecord.getSessionState().setRemoteRegistrationId(preKey.getRegistrationId());
+      sessionRecord.getSessionState().setAliceBaseKey(ourBaseKey.getPublicKey().serialize());
+
+      identityKeyStore.saveIdentity(remoteAddress, preKey.getIdentityKey());
+      sessionStore.storeSession(remoteAddress, sessionRecord);
+    }
+  }
+
+}

java/src/main/java/org/whispersystems/libsignal/SessionCipher.java

@@ -1,40 +1,29 @@
-/** 
- * Copyright (C) 2013 Open Whisper Systems
- * 
- * This program is free software: you can redistribute it and/or modify
- * it under the terms of the GNU General Public License as published by
- * the Free Software Foundation, either version 3 of the License, or
- * (at your option) any later version.
+/**
+ * Copyright (C) 2014-2016 Open Whisper Systems
  *
- * This program is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
- * GNU General Public License for more details.
- * 
- * You should have received a copy of the GNU General Public License
- * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ * Licensed according to the LICENSE file in this repository.
  */
-package org.whispersystems.libaxolotl;
+package org.whispersystems.libsignal;
 
-import org.whispersystems.libaxolotl.ecc.Curve;
-import org.whispersystems.libaxolotl.ecc.ECKeyPair;
-import org.whispersystems.libaxolotl.ecc.ECPublicKey;
-import org.whispersystems.libaxolotl.protocol.CiphertextMessage;
-import org.whispersystems.libaxolotl.protocol.PreKeyWhisperMessage;
-import org.whispersystems.libaxolotl.protocol.WhisperMessage;
-import org.whispersystems.libaxolotl.ratchet.ChainKey;
-import org.whispersystems.libaxolotl.ratchet.MessageKeys;
-import org.whispersystems.libaxolotl.ratchet.RootKey;
-import org.whispersystems.libaxolotl.state.AxolotlStore;
-import org.whispersystems.libaxolotl.state.IdentityKeyStore;
-import org.whispersystems.libaxolotl.state.PreKeyStore;
-import org.whispersystems.libaxolotl.state.SessionRecord;
-import org.whispersystems.libaxolotl.state.SessionState;
-import org.whispersystems.libaxolotl.state.SessionStore;
-import org.whispersystems.libaxolotl.state.SignedPreKeyStore;
-import org.whispersystems.libaxolotl.util.ByteUtil;
-import org.whispersystems.libaxolotl.util.Pair;
-import org.whispersystems.libaxolotl.util.guava.Optional;
+import org.whispersystems.libsignal.ecc.Curve;
+import org.whispersystems.libsignal.ecc.ECKeyPair;
+import org.whispersystems.libsignal.ecc.ECPublicKey;
+import org.whispersystems.libsignal.protocol.CiphertextMessage;
+import org.whispersystems.libsignal.protocol.PreKeySignalMessage;
+import org.whispersystems.libsignal.protocol.SignalMessage;
+import org.whispersystems.libsignal.ratchet.ChainKey;
+import org.whispersystems.libsignal.ratchet.MessageKeys;
+import org.whispersystems.libsignal.ratchet.RootKey;
+import org.whispersystems.libsignal.state.SignalProtocolStore;
+import org.whispersystems.libsignal.state.IdentityKeyStore;
+import org.whispersystems.libsignal.state.PreKeyStore;
+import org.whispersystems.libsignal.state.SessionRecord;
+import org.whispersystems.libsignal.state.SessionState;
+import org.whispersystems.libsignal.state.SessionStore;
+import org.whispersystems.libsignal.state.SignedPreKeyStore;
+import org.whispersystems.libsignal.util.ByteUtil;
+import org.whispersystems.libsignal.util.Pair;
+import org.whispersystems.libsignal.util.guava.Optional;
 
 import java.security.InvalidAlgorithmParameterException;
 import java.security.NoSuchAlgorithmException;
@@ -49,10 +38,10 @@ import javax.crypto.NoSuchPaddingException;
 import javax.crypto.spec.IvParameterSpec;
 import javax.crypto.spec.SecretKeySpec;
 
-import static org.whispersystems.libaxolotl.state.SessionState.UnacknowledgedPreKeyMessageItems;
+import static org.whispersystems.libsignal.state.SessionState.UnacknowledgedPreKeyMessageItems;
 
 /**
- * The main entry point for Axolotl encrypt/decrypt operations.
+ * The main entry point for Signal Protocol encrypt/decrypt operations.
  *
  * Once a session has been established with {@link SessionBuilder},
  * this class can be used for all encrypt/decrypt operations within
@@ -64,10 +53,11 @@ public class SessionCipher {
 
   public static final Object SESSION_LOCK = new Object();
 
-  private final SessionStore   sessionStore;
-  private final SessionBuilder sessionBuilder;
-  private final PreKeyStore    preKeyStore;
-  private final AxolotlAddress remoteAddress;
+  private final SessionStore          sessionStore;
+  private final IdentityKeyStore      identityKeyStore;
+  private final SessionBuilder        sessionBuilder;
+  private final PreKeyStore           preKeyStore;
+  private final SignalProtocolAddress remoteAddress;
 
   /**
    * Construct a SessionCipher for encrypt/decrypt operations on a session.
@@ -79,16 +69,17 @@ public class SessionCipher {
    */
   public SessionCipher(SessionStore sessionStore, PreKeyStore preKeyStore,
                        SignedPreKeyStore signedPreKeyStore, IdentityKeyStore identityKeyStore,
-                       AxolotlAddress remoteAddress)
+                       SignalProtocolAddress remoteAddress)
   {
-    this.sessionStore   = sessionStore;
-    this.preKeyStore    = preKeyStore;
-    this.remoteAddress  = remoteAddress;
-    this.sessionBuilder = new SessionBuilder(sessionStore, preKeyStore, signedPreKeyStore,
-                                             identityKeyStore, remoteAddress);
+    this.sessionStore     = sessionStore;
+    this.preKeyStore      = preKeyStore;
+    this.identityKeyStore = identityKeyStore;
+    this.remoteAddress    = remoteAddress;
+    this.sessionBuilder   = new SessionBuilder(sessionStore, preKeyStore, signedPreKeyStore,
+                                               identityKeyStore, remoteAddress);
   }
 
-  public SessionCipher(AxolotlStore store, AxolotlAddress remoteAddress) {
+  public SessionCipher(SignalProtocolStore store, SignalProtocolAddress remoteAddress) {
     this(store, store, store, store, remoteAddress);
   }
 
@@ -98,7 +89,7 @@ public class SessionCipher {
    * @param  paddedMessage The plaintext message bytes, optionally padded to a constant multiple.
    * @return A ciphertext message encrypted to the recipient+device tuple.
    */
-  public CiphertextMessage encrypt(byte[] paddedMessage) {
+  public CiphertextMessage encrypt(byte[] paddedMessage) throws UntrustedIdentityException {
     synchronized (SESSION_LOCK) {
       SessionRecord sessionRecord   = sessionStore.loadSession(remoteAddress);
       SessionState  sessionState    = sessionRecord.getSessionState();
@@ -108,24 +99,30 @@ public class SessionCipher {
       int           previousCounter = sessionState.getPreviousCounter();
       int           sessionVersion  = sessionState.getSessionVersion();
 
-      byte[]            ciphertextBody    = getCiphertext(sessionVersion, messageKeys, paddedMessage);
-      CiphertextMessage ciphertextMessage = new WhisperMessage(sessionVersion, messageKeys.getMacKey(),
-                                                               senderEphemeral, chainKey.getIndex(),
-                                                               previousCounter, ciphertextBody,
-                                                               sessionState.getLocalIdentityKey(),
-                                                               sessionState.getRemoteIdentityKey());
+      byte[]            ciphertextBody    = getCiphertext(messageKeys, paddedMessage);
+      CiphertextMessage ciphertextMessage = new SignalMessage(sessionVersion, messageKeys.getMacKey(),
+                                                              senderEphemeral, chainKey.getIndex(),
+                                                              previousCounter, ciphertextBody,
+                                                              sessionState.getLocalIdentityKey(),
+                                                              sessionState.getRemoteIdentityKey());
 
       if (sessionState.hasUnacknowledgedPreKeyMessage()) {
         UnacknowledgedPreKeyMessageItems items = sessionState.getUnacknowledgedPreKeyMessageItems();
         int localRegistrationId = sessionState.getLocalRegistrationId();
 
-        ciphertextMessage = new PreKeyWhisperMessage(sessionVersion, localRegistrationId, items.getPreKeyId(),
-                                                     items.getSignedPreKeyId(), items.getBaseKey(),
-                                                     sessionState.getLocalIdentityKey(),
-                                                     (WhisperMessage) ciphertextMessage);
+        ciphertextMessage = new PreKeySignalMessage(sessionVersion, localRegistrationId, items.getPreKeyId(),
+                                                    items.getSignedPreKeyId(), items.getBaseKey(),
+                                                    sessionState.getLocalIdentityKey(),
+                                                    (SignalMessage) ciphertextMessage);
       }
 
       sessionState.setSenderChainKey(chainKey.getNextChainKey());
+
+      if (!identityKeyStore.isTrustedIdentity(remoteAddress, sessionState.getRemoteIdentityKey(), IdentityKeyStore.Direction.SENDING)) {
+        throw new UntrustedIdentityException(remoteAddress.getName(), sessionState.getRemoteIdentityKey());
+      }
+
+      identityKeyStore.saveIdentity(remoteAddress, sessionState.getRemoteIdentityKey());
       sessionStore.storeSession(remoteAddress, sessionRecord);
       return ciphertextMessage;
     }
@@ -134,19 +131,19 @@ public class SessionCipher {
   /**
    * Decrypt a message.
    *
-   * @param  ciphertext The {@link PreKeyWhisperMessage} to decrypt.
+   * @param  ciphertext The {@link PreKeySignalMessage} to decrypt.
    *
    * @return The plaintext.
    * @throws InvalidMessageException if the input is not valid ciphertext.
    * @throws DuplicateMessageException if the input is a message that has already been received.
    * @throws LegacyMessageException if the input is a message formatted by a protocol version that
    *                                is no longer supported.
-   * @throws InvalidKeyIdException when there is no local {@link org.whispersystems.libaxolotl.state.PreKeyRecord}
+   * @throws InvalidKeyIdException when there is no local {@link org.whispersystems.libsignal.state.PreKeyRecord}
    *                               that corresponds to the PreKey ID in the message.
    * @throws InvalidKeyException when the message is formatted incorrectly.
    * @throws UntrustedIdentityException when the {@link IdentityKey} of the sender is untrusted.
    */
-  public byte[] decrypt(PreKeyWhisperMessage ciphertext)
+  public byte[] decrypt(PreKeySignalMessage ciphertext)
       throws DuplicateMessageException, LegacyMessageException, InvalidMessageException,
              InvalidKeyIdException, InvalidKeyException, UntrustedIdentityException
   {
@@ -156,7 +153,7 @@ public class SessionCipher {
   /**
    * Decrypt a message.
    *
-   * @param  ciphertext The {@link PreKeyWhisperMessage} to decrypt.
+   * @param  ciphertext The {@link PreKeySignalMessage} to decrypt.
    * @param  callback   A callback that is triggered after decryption is complete,
    *                    but before the updated session state has been committed to the session
    *                    DB.  This allows some implementations to store the committed plaintext
@@ -169,12 +166,12 @@ public class SessionCipher {
    * @throws DuplicateMessageException if the input is a message that has already been received.
    * @throws LegacyMessageException if the input is a message formatted by a protocol version that
    *                                is no longer supported.
-   * @throws InvalidKeyIdException when there is no local {@link org.whispersystems.libaxolotl.state.PreKeyRecord}
+   * @throws InvalidKeyIdException when there is no local {@link org.whispersystems.libsignal.state.PreKeyRecord}
    *                               that corresponds to the PreKey ID in the message.
    * @throws InvalidKeyException when the message is formatted incorrectly.
    * @throws UntrustedIdentityException when the {@link IdentityKey} of the sender is untrusted.
    */
-  public byte[] decrypt(PreKeyWhisperMessage ciphertext, DecryptionCallback callback)
+  public byte[] decrypt(PreKeySignalMessage ciphertext, DecryptionCallback callback)
       throws DuplicateMessageException, LegacyMessageException, InvalidMessageException,
              InvalidKeyIdException, InvalidKeyException, UntrustedIdentityException
   {
@@ -198,7 +195,7 @@ public class SessionCipher {
   /**
    * Decrypt a message.
    *
-   * @param  ciphertext The {@link WhisperMessage} to decrypt.
+   * @param  ciphertext The {@link SignalMessage} to decrypt.
    *
    * @return The plaintext.
    * @throws InvalidMessageException if the input is not valid ciphertext.
@@ -207,9 +204,9 @@ public class SessionCipher {
    *                                is no longer supported.
    * @throws NoSessionException if there is no established session for this contact.
    */
-  public byte[] decrypt(WhisperMessage ciphertext)
+  public byte[] decrypt(SignalMessage ciphertext)
       throws InvalidMessageException, DuplicateMessageException, LegacyMessageException,
-      NoSessionException
+      NoSessionException, UntrustedIdentityException
   {
     return decrypt(ciphertext, new NullDecryptionCallback());
   }
@@ -217,7 +214,7 @@ public class SessionCipher {
   /**
    * Decrypt a message.
    *
-   * @param  ciphertext The {@link WhisperMessage} to decrypt.
+   * @param  ciphertext The {@link SignalMessage} to decrypt.
    * @param  callback   A callback that is triggered after decryption is complete,
    *                    but before the updated session state has been committed to the session
    *                    DB.  This allows some implementations to store the committed plaintext
@@ -232,9 +229,9 @@ public class SessionCipher {
    *                                is no longer supported.
    * @throws NoSessionException if there is no established session for this contact.
    */
-  public byte[] decrypt(WhisperMessage ciphertext, DecryptionCallback callback)
+  public byte[] decrypt(SignalMessage ciphertext, DecryptionCallback callback)
       throws InvalidMessageException, DuplicateMessageException, LegacyMessageException,
-             NoSessionException
+             NoSessionException, UntrustedIdentityException
   {
     synchronized (SESSION_LOCK) {
 
@@ -245,6 +242,12 @@ public class SessionCipher {
       SessionRecord sessionRecord = sessionStore.loadSession(remoteAddress);
       byte[]        plaintext     = decrypt(sessionRecord, ciphertext);
 
+      if (!identityKeyStore.isTrustedIdentity(remoteAddress, sessionRecord.getSessionState().getRemoteIdentityKey(), IdentityKeyStore.Direction.RECEIVING)) {
+        throw new UntrustedIdentityException(remoteAddress.getName(), sessionRecord.getSessionState().getRemoteIdentityKey());
+      }
+
+      identityKeyStore.saveIdentity(remoteAddress, sessionRecord.getSessionState().getRemoteIdentityKey());
+
       callback.handlePlaintext(plaintext);
 
       sessionStore.storeSession(remoteAddress, sessionRecord);
@@ -253,7 +256,7 @@ public class SessionCipher {
     }
   }
 
-  private byte[] decrypt(SessionRecord sessionRecord, WhisperMessage ciphertext)
+  private byte[] decrypt(SessionRecord sessionRecord, SignalMessage ciphertext)
       throws DuplicateMessageException, LegacyMessageException, InvalidMessageException
   {
     synchronized (SESSION_LOCK) {
@@ -288,7 +291,7 @@ public class SessionCipher {
     }
   }
 
-  private byte[] decrypt(SessionState sessionState, WhisperMessage ciphertextMessage)
+  private byte[] decrypt(SessionState sessionState, SignalMessage ciphertextMessage)
       throws InvalidMessageException, DuplicateMessageException, LegacyMessageException
   {
     if (!sessionState.hasSenderChain()) {
@@ -301,19 +304,17 @@ public class SessionCipher {
                                                       sessionState.getSessionVersion()));
     }
 
-    int            messageVersion    = ciphertextMessage.getMessageVersion();
     ECPublicKey    theirEphemeral    = ciphertextMessage.getSenderRatchetKey();
     int            counter           = ciphertextMessage.getCounter();
     ChainKey       chainKey          = getOrCreateChainKey(sessionState, theirEphemeral);
     MessageKeys    messageKeys       = getOrCreateMessageKeys(sessionState, theirEphemeral,
                                                               chainKey, counter);
 
-    ciphertextMessage.verifyMac(messageVersion,
-                                sessionState.getRemoteIdentityKey(),
+    ciphertextMessage.verifyMac(sessionState.getRemoteIdentityKey(),
                                 sessionState.getLocalIdentityKey(),
                                 messageKeys.getMacKey());
 
-    byte[] plaintext = getPlaintext(messageVersion, messageKeys, ciphertextMessage.getBody());
+    byte[] plaintext = getPlaintext(messageKeys, ciphertextMessage.getBody());
 
     sessionState.clearUnacknowledgedPreKeyMessage();
 
@@ -391,58 +392,26 @@ public class SessionCipher {
     return chainKey.getMessageKeys();
   }
 
-  private byte[] getCiphertext(int version, MessageKeys messageKeys, byte[] plaintext) {
+  private byte[] getCiphertext(MessageKeys messageKeys, byte[] plaintext) {
     try {
-      Cipher cipher;
-
-      if (version >= 3) {
-        cipher = getCipher(Cipher.ENCRYPT_MODE, messageKeys.getCipherKey(), messageKeys.getIv());
-      } else {
-        cipher = getCipher(Cipher.ENCRYPT_MODE, messageKeys.getCipherKey(), messageKeys.getCounter());
-      }
-
+      Cipher cipher = getCipher(Cipher.ENCRYPT_MODE, messageKeys.getCipherKey(), messageKeys.getIv());
       return cipher.doFinal(plaintext);
     } catch (IllegalBlockSizeException | BadPaddingException e) {
       throw new AssertionError(e);
     }
   }
 
-  private byte[] getPlaintext(int version, MessageKeys messageKeys, byte[] cipherText)
+  private byte[] getPlaintext(MessageKeys messageKeys, byte[] cipherText)
       throws InvalidMessageException
   {
     try {
-      Cipher cipher;
-
-      if (version >= 3) {
-        cipher = getCipher(Cipher.DECRYPT_MODE, messageKeys.getCipherKey(), messageKeys.getIv());
-      } else {
-        cipher = getCipher(Cipher.DECRYPT_MODE, messageKeys.getCipherKey(), messageKeys.getCounter());
-      }
-
+      Cipher cipher = getCipher(Cipher.DECRYPT_MODE, messageKeys.getCipherKey(), messageKeys.getIv());
       return cipher.doFinal(cipherText);
     } catch (IllegalBlockSizeException | BadPaddingException e) {
       throw new InvalidMessageException(e);
     }
   }
 
-  private Cipher getCipher(int mode, SecretKeySpec key, int counter)  {
-    try {
-      Cipher cipher = Cipher.getInstance("AES/CTR/NoPadding");
-
-      byte[] ivBytes = new byte[16];
-      ByteUtil.intToByteArray(ivBytes, 0, counter);
-
-      IvParameterSpec iv = new IvParameterSpec(ivBytes);
-      cipher.init(mode, key, iv);
-
-      return cipher;
-    } catch (NoSuchAlgorithmException | NoSuchPaddingException | java.security.InvalidKeyException |
-             InvalidAlgorithmParameterException e)
-    {
-      throw new AssertionError(e);
-    }
-  }
-
   private Cipher getCipher(int mode, SecretKeySpec key, IvParameterSpec iv) {
     try {
       Cipher cipher = Cipher.getInstance("AES/CBC/PKCS5Padding");

java/src/main/java/org/whispersystems/libsignal/SignalProtocolAddress.java

@@ -1,11 +1,16 @@
-package org.whispersystems.libaxolotl;
+/**
+ * Copyright (C) 2014-2016 Open Whisper Systems
+ *
+ * Licensed according to the LICENSE file in this repository.
+ */
+package org.whispersystems.libsignal;
 
-public class AxolotlAddress {
+public class SignalProtocolAddress {
 
   private final String name;
   private final int    deviceId;
 
-  public AxolotlAddress(String name, int deviceId) {
+  public SignalProtocolAddress(String name, int deviceId) {
     this.name     = name;
     this.deviceId = deviceId;
   }
@@ -26,9 +31,9 @@ public class AxolotlAddress {
   @Override
   public boolean equals(Object other) {
     if (other == null)                       return false;
-    if (!(other instanceof  AxolotlAddress)) return false;
+    if (!(other instanceof SignalProtocolAddress)) return false;
 
-    AxolotlAddress that = (AxolotlAddress)other;
+    SignalProtocolAddress that = (SignalProtocolAddress)other;
     return this.name.equals(that.name) && this.deviceId == that.deviceId;
   }
 

java/src/main/java/org/whispersystems/libsignal/StaleKeyExchangeException.java

@@ -0,0 +1,9 @@
+/**
+ * Copyright (C) 2014-2016 Open Whisper Systems
+ *
+ * Licensed according to the LICENSE file in this repository.
+ */
+package org.whispersystems.libsignal;
+
+public class StaleKeyExchangeException extends Throwable {
+}

java/src/main/java/org/whispersystems/libsignal/UntrustedIdentityException.java

@@ -1,4 +1,9 @@
-package org.whispersystems.libaxolotl;
+/**
+ * Copyright (C) 2014-2016 Open Whisper Systems
+ *
+ * Licensed according to the LICENSE file in this repository.
+ */
+package org.whispersystems.libsignal;
 
 public class UntrustedIdentityException extends Exception {
 

java/src/main/java/org/whispersystems/libsignal/devices/DeviceConsistencyCodeGenerator.java

@@ -0,0 +1,54 @@
+package org.whispersystems.libsignal.devices;
+
+import org.whispersystems.libsignal.util.ByteArrayComparator;
+import org.whispersystems.libsignal.util.ByteUtil;
+
+import java.security.MessageDigest;
+import java.security.NoSuchAlgorithmException;
+import java.util.ArrayList;
+import java.util.Collections;
+import java.util.Comparator;
+import java.util.List;
+
+public class DeviceConsistencyCodeGenerator {
+
+  private static final int CODE_VERSION = 0;
+
+  public static String generateFor(DeviceConsistencyCommitment commitment,
+                                   List<DeviceConsistencySignature> signatures)
+  {
+    try {
+      ArrayList<DeviceConsistencySignature> sortedSignatures = new ArrayList<>(signatures);
+      Collections.sort(sortedSignatures, new SignatureComparator());
+
+      MessageDigest messageDigest = MessageDigest.getInstance("SHA-512");
+      messageDigest.update(ByteUtil.shortToByteArray(CODE_VERSION));
+      messageDigest.update(commitment.toByteArray());
+
+      for (DeviceConsistencySignature signature : sortedSignatures) {
+        messageDigest.update(signature.getVrfOutput());
+      }
+
+      byte[] hash = messageDigest.digest();
+
+      String digits = getEncodedChunk(hash, 0) + getEncodedChunk(hash, 5);
+      return digits.substring(0, 6);
+
+    } catch (NoSuchAlgorithmException e) {
+      throw new AssertionError(e);
+    }
+  }
+
+  private static String getEncodedChunk(byte[] hash, int offset) {
+    long chunk = ByteUtil.byteArray5ToLong(hash, offset) % 100000;
+    return String.format("%05d", chunk);
+  }
+
+
+  private static class SignatureComparator extends ByteArrayComparator implements Comparator<DeviceConsistencySignature> {
+    @Override
+    public int compare(DeviceConsistencySignature first, DeviceConsistencySignature second) {
+      return compare(first.getVrfOutput(), second.getVrfOutput());
+    }
+  }
+}

java/src/main/java/org/whispersystems/libsignal/devices/DeviceConsistencyCommitment.java

@@ -0,0 +1,49 @@
+package org.whispersystems.libsignal.devices;
+
+import org.whispersystems.libsignal.IdentityKey;
+import org.whispersystems.libsignal.util.ByteUtil;
+import org.whispersystems.libsignal.util.IdentityKeyComparator;
+
+import java.security.MessageDigest;
+import java.security.NoSuchAlgorithmException;
+import java.util.ArrayList;
+import java.util.Collections;
+import java.util.List;
+
+public class DeviceConsistencyCommitment {
+
+  private static final String VERSION = "DeviceConsistencyCommitment_V0";
+
+  private final int generation;
+  private final byte[] serialized;
+
+  public DeviceConsistencyCommitment(int generation, List<IdentityKey> identityKeys) {
+    try {
+      ArrayList<IdentityKey> sortedIdentityKeys = new ArrayList<>(identityKeys);
+      Collections.sort(sortedIdentityKeys, new IdentityKeyComparator());
+
+      MessageDigest messageDigest = MessageDigest.getInstance("SHA-512");
+      messageDigest.update(VERSION.getBytes());
+      messageDigest.update(ByteUtil.intToByteArray(generation));
+
+      for (IdentityKey commitment : sortedIdentityKeys) {
+        messageDigest.update(commitment.getPublicKey().serialize());
+      }
+
+      this.generation = generation;
+      this.serialized = messageDigest.digest();
+    } catch (NoSuchAlgorithmException e) {
+      throw new AssertionError(e);
+    }
+  }
+
+  public byte[] toByteArray() {
+    return serialized;
+  }
+
+  public int getGeneration() {
+    return generation;
+  }
+
+
+}

java/src/main/java/org/whispersystems/libsignal/devices/DeviceConsistencySignature.java

@@ -0,0 +1,21 @@
+package org.whispersystems.libsignal.devices;
+
+public class DeviceConsistencySignature {
+
+  private final byte[] signature;
+  private final byte[] vrfOutput;
+
+  public DeviceConsistencySignature(byte[] signature, byte[] vrfOutput) {
+    this.signature = signature;
+    this.vrfOutput = vrfOutput;
+  }
+
+  public byte[] getVrfOutput() {
+    return vrfOutput;
+  }
+
+  public byte[] getSignature() {
+    return signature;
+  }
+
+}

java/src/main/java/org/whispersystems/libsignal/ecc/Curve.java

@@ -1,25 +1,14 @@
 /**
- * Copyright (C) 2013 Open Whisper Systems
+ * Copyright (C) 2013-2016 Open Whisper Systems
  *
- * This program is free software: you can redistribute it and/or modify
- * it under the terms of the GNU General Public License as published by
- * the Free Software Foundation, either version 3 of the License, or
- * (at your option) any later version.
- *
- * This program is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
- * GNU General Public License for more details.
- *
- * You should have received a copy of the GNU General Public License
- * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ * Licensed according to the LICENSE file in this repository.
  */
-package org.whispersystems.libaxolotl.ecc;
+package org.whispersystems.libsignal.ecc;
 
 import org.whispersystems.curve25519.Curve25519;
 import org.whispersystems.curve25519.Curve25519KeyPair;
-import org.whispersystems.curve25519.NoSuchProviderException;
-import org.whispersystems.libaxolotl.InvalidKeyException;
+import org.whispersystems.curve25519.VrfSignatureVerificationFailedException;
+import org.whispersystems.libsignal.InvalidKeyException;
 
 import static org.whispersystems.curve25519.Curve25519.BEST;
 
@@ -41,10 +30,18 @@ public class Curve {
   public static ECPublicKey decodePoint(byte[] bytes, int offset)
       throws InvalidKeyException
   {
+    if (bytes == null || bytes.length - offset < 1) {
+      throw new InvalidKeyException("No key type identifier");
+    }
+
     int type = bytes[offset] & 0xFF;
 
     switch (type) {
       case Curve.DJB_TYPE:
+        if (bytes.length - offset < 33) {
+          throw new InvalidKeyException("Bad key length: " + bytes.length);
+        }
+
         byte[] keyBytes = new byte[32];
         System.arraycopy(bytes, offset+1, keyBytes, 0, keyBytes.length);
         return new DjbECPublicKey(keyBytes);
@@ -60,6 +57,14 @@ public class Curve {
   public static byte[] calculateAgreement(ECPublicKey publicKey, ECPrivateKey privateKey)
       throws InvalidKeyException
   {
+    if (publicKey == null) {
+      throw new InvalidKeyException("public value is null");
+    }
+
+    if (privateKey == null) {
+      throw new InvalidKeyException("private value is null");
+    }
+
     if (publicKey.getType() != privateKey.getType()) {
       throw new InvalidKeyException("Public and private keys must be of the same type!");
     }
@@ -76,6 +81,10 @@ public class Curve {
   public static boolean verifySignature(ECPublicKey signingKey, byte[] message, byte[] signature)
       throws InvalidKeyException
   {
+    if (signingKey == null || message == null || signature == null) {
+      throw new InvalidKeyException("Values must not be null");
+    }
+
     if (signingKey.getType() == DJB_TYPE) {
       return Curve25519.getInstance(BEST)
                        .verifySignature(((DjbECPublicKey) signingKey).getPublicKey(), message, signature);
@@ -87,6 +96,10 @@ public class Curve {
   public static byte[] calculateSignature(ECPrivateKey signingKey, byte[] message)
       throws InvalidKeyException
   {
+    if (signingKey == null || message == null) {
+      throw new InvalidKeyException("Values must not be null");
+    }
+
     if (signingKey.getType() == DJB_TYPE) {
       return Curve25519.getInstance(BEST)
                        .calculateSignature(((DjbECPrivateKey) signingKey).getPrivateKey(), message);
@@ -94,4 +107,35 @@ public class Curve {
       throw new InvalidKeyException("Unknown type: " + signingKey.getType());
     }
   }
+
+  public static byte[] calculateVrfSignature(ECPrivateKey signingKey, byte[] message)
+      throws InvalidKeyException
+  {
+    if (signingKey == null || message == null) {
+      throw new InvalidKeyException("Values must not be null");
+    }
+
+    if (signingKey.getType() == DJB_TYPE) {
+      return Curve25519.getInstance(BEST)
+                       .calculateVrfSignature(((DjbECPrivateKey)signingKey).getPrivateKey(), message);
+    } else {
+      throw new InvalidKeyException("Unknown type: " + signingKey.getType());
+    }
+  }
+
+  public static byte[] verifyVrfSignature(ECPublicKey signingKey, byte[] message, byte[] signature)
+      throws InvalidKeyException, VrfSignatureVerificationFailedException
+  {
+    if (signingKey == null || message == null || signature == null) {
+      throw new InvalidKeyException("Values must not be null");
+    }
+
+    if (signingKey.getType() == DJB_TYPE) {
+      return Curve25519.getInstance(BEST)
+                       .verifyVrfSignature(((DjbECPublicKey) signingKey).getPublicKey(), message, signature);
+    } else {
+      throw new InvalidKeyException("Unknown type: " + signingKey.getType());
+    }
+  }
+
 }

java/src/main/java/org/whispersystems/libsignal/ecc/DjbECPrivateKey.java

@@ -0,0 +1,30 @@
+/**
+ * Copyright (C) 2013-2016 Open Whisper Systems
+ *
+ * Licensed according to the LICENSE file in this repository.
+ */
+
+package org.whispersystems.libsignal.ecc;
+
+public class DjbECPrivateKey implements ECPrivateKey {
+
+  private final byte[] privateKey;
+
+  DjbECPrivateKey(byte[] privateKey) {
+    this.privateKey = privateKey;
+  }
+
+  @Override
+  public byte[] serialize() {
+    return privateKey;
+  }
+
+  @Override
+  public int getType() {
+    return Curve.DJB_TYPE;
+  }
+
+  public byte[] getPrivateKey() {
+    return privateKey;
+  }
+}

java/src/main/java/org/whispersystems/libsignal/ecc/DjbECPublicKey.java

@@ -1,23 +1,12 @@
 /**
- * Copyright (C) 2013 Open Whisper Systems
+ * Copyright (C) 2013-2016 Open Whisper Systems
  *
- * This program is free software: you can redistribute it and/or modify
- * it under the terms of the GNU General Public License as published by
- * the Free Software Foundation, either version 3 of the License, or
- * (at your option) any later version.
- *
- * This program is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
- * GNU General Public License for more details.
- *
- * You should have received a copy of the GNU General Public License
- * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ * Licensed according to the LICENSE file in this repository.
  */
 
-package org.whispersystems.libaxolotl.ecc;
+package org.whispersystems.libsignal.ecc;
 
-import org.whispersystems.libaxolotl.util.ByteUtil;
+import org.whispersystems.libsignal.util.ByteUtil;
 
 import java.math.BigInteger;
 import java.util.Arrays;

java/src/main/java/org/whispersystems/libsignal/ecc/ECKeyPair.java

@@ -0,0 +1,25 @@
+/**
+ * Copyright (C) 2013-2016 Open Whisper Systems
+ *
+ * Licensed according to the LICENSE file in this repository.
+ */
+package org.whispersystems.libsignal.ecc;
+
+public class ECKeyPair {
+
+  private final ECPublicKey  publicKey;
+  private final ECPrivateKey privateKey;
+
+  public ECKeyPair(ECPublicKey publicKey, ECPrivateKey privateKey) {
+    this.publicKey = publicKey;
+    this.privateKey = privateKey;
+  }
+
+  public ECPublicKey getPublicKey() {
+    return publicKey;
+  }
+
+  public ECPrivateKey getPrivateKey() {
+    return privateKey;
+  }
+}

java/src/main/java/org/whispersystems/libsignal/ecc/ECPrivateKey.java

@@ -0,0 +1,12 @@
+/**
+ * Copyright (C) 2013-2016 Open Whisper Systems
+ *
+ * Licensed according to the LICENSE file in this repository.
+ */
+
+package org.whispersystems.libsignal.ecc;
+
+public interface ECPrivateKey {
+  public byte[] serialize();
+  public int getType();
+}

java/src/main/java/org/whispersystems/libsignal/ecc/ECPublicKey.java

@@ -0,0 +1,16 @@
+/**
+ * Copyright (C) 2013-2016 Open Whisper Systems
+ *
+ * Licensed according to the LICENSE file in this repository.
+ */
+
+package org.whispersystems.libsignal.ecc;
+
+public interface ECPublicKey extends Comparable<ECPublicKey> {
+
+  public static final int KEY_SIZE = 33;
+
+  public byte[] serialize();
+
+  public int getType();
+}

java/src/main/java/org/whispersystems/libsignal/fingerprint/DisplayableFingerprint.java

@@ -0,0 +1,43 @@
+/**
+ * Copyright (C) 2016 Open Whisper Systems
+ *
+ * Licensed according to the LICENSE file in this repository.
+ */
+package org.whispersystems.libsignal.fingerprint;
+
+import org.whispersystems.libsignal.util.ByteUtil;
+
+public class DisplayableFingerprint {
+
+  private final String localFingerprintNumbers;
+  private final String remoteFingerprintNumbers;
+
+  DisplayableFingerprint(byte[] localFingerprint, byte[] remoteFingerprint)
+  {
+    this.localFingerprintNumbers  = getDisplayStringFor(localFingerprint);
+    this.remoteFingerprintNumbers = getDisplayStringFor(remoteFingerprint);
+  }
+
+  public String getDisplayText() {
+    if (localFingerprintNumbers.compareTo(remoteFingerprintNumbers) <= 0) {
+      return localFingerprintNumbers + remoteFingerprintNumbers;
+    } else {
+      return remoteFingerprintNumbers + localFingerprintNumbers;
+    }
+  }
+
+  private String getDisplayStringFor(byte[] fingerprint) {
+    return getEncodedChunk(fingerprint, 0)  +
+           getEncodedChunk(fingerprint, 5)  +
+           getEncodedChunk(fingerprint, 10) +
+           getEncodedChunk(fingerprint, 15) +
+           getEncodedChunk(fingerprint, 20) +
+           getEncodedChunk(fingerprint, 25);
+  }
+
+  private String getEncodedChunk(byte[] hash, int offset) {
+    long chunk = ByteUtil.byteArray5ToLong(hash, offset) % 100000;
+    return String.format("%05d", chunk);
+  }
+
+}

java/src/main/java/org/whispersystems/libsignal/fingerprint/Fingerprint.java

@@ -1,4 +1,9 @@
-package org.whispersystems.libaxolotl.fingerprint;
+/**
+ * Copyright (C) 2016 Open Whisper Systems
+ *
+ * Licensed according to the LICENSE file in this repository.
+ */
+package org.whispersystems.libsignal.fingerprint;
 
 public class Fingerprint {
 
@@ -20,7 +25,7 @@ public class Fingerprint {
   }
 
   /**
-   * @return A scannable fingerprint that can be scanned anc compared locally.
+   * @return A scannable fingerprint that can be scanned and compared locally.
    */
   public ScannableFingerprint getScannableFingerprint() {
     return scannableFingerprint;

java/src/main/java/org/whispersystems/libsignal/fingerprint/FingerprintGenerator.java

@@ -0,0 +1,24 @@
+/**
+ * Copyright (C) 2016 Open Whisper Systems
+ *
+ * Licensed according to the LICENSE file in this repository.
+ */
+package org.whispersystems.libsignal.fingerprint;
+
+import org.whispersystems.libsignal.IdentityKey;
+
+import java.util.List;
+
+public interface FingerprintGenerator {
+  public Fingerprint createFor(int version,
+                               byte[] localStableIdentifier,
+                               IdentityKey localIdentityKey,
+                               byte[] remoteStableIdentifier,
+                               IdentityKey remoteIdentityKey);
+
+  public Fingerprint createFor(int version,
+                               byte[] localStableIdentifier,
+                               List<IdentityKey> localIdentityKey,
+                               byte[] remoteStableIdentifier,
+                               List<IdentityKey> remoteIdentityKey);
+}

java/src/main/java/org/whispersystems/libsignal/fingerprint/FingerprintIdentifierMismatchException.java

@@ -1,4 +1,9 @@
-package org.whispersystems.libaxolotl.fingerprint;
+/**
+ * Copyright (C) 2016 Open Whisper Systems
+ *
+ * Licensed according to the LICENSE file in this repository.
+ */
+package org.whispersystems.libsignal.fingerprint;
 
 public class FingerprintIdentifierMismatchException extends Exception {
 

java/src/main/java/org/whispersystems/libsignal/fingerprint/FingerprintParsingException.java

@@ -0,0 +1,14 @@
+/**
+ * Copyright (C) 2016 Open Whisper Systems
+ *
+ * Licensed according to the LICENSE file in this repository.
+ */
+package org.whispersystems.libsignal.fingerprint;
+
+public class FingerprintParsingException extends Exception {
+
+  public FingerprintParsingException(Exception nested) {
+    super(nested);
+  }
+
+}

java/src/main/java/org/whispersystems/libsignal/fingerprint/FingerprintVersionMismatchException.java

@@ -0,0 +1,26 @@
+/**
+ * Copyright (C) 2016 Open Whisper Systems
+ *
+ * Licensed according to the LICENSE file in this repository.
+ */
+package org.whispersystems.libsignal.fingerprint;
+
+public class FingerprintVersionMismatchException extends Exception {
+
+  private final int theirVersion;
+  private final int ourVersion;
+
+  public FingerprintVersionMismatchException(int theirVersion, int ourVersion) {
+    super();
+    this.theirVersion = theirVersion;
+    this.ourVersion   = ourVersion;
+  }
+
+  public int getTheirVersion() {
+    return theirVersion;
+  }
+
+  public int getOurVersion() {
+    return ourVersion;
+  }
+}

java/src/main/java/org/whispersystems/libsignal/fingerprint/NumericFingerprintGenerator.java

@@ -0,0 +1,137 @@
+/**
+ * Copyright (C) 2016 Open Whisper Systems
+ *
+ * Licensed according to the LICENSE file in this repository.
+ */
+package org.whispersystems.libsignal.fingerprint;
+
+import org.whispersystems.libsignal.IdentityKey;
+import org.whispersystems.libsignal.util.ByteUtil;
+import org.whispersystems.libsignal.util.IdentityKeyComparator;
+
+import java.io.ByteArrayOutputStream;
+import java.security.MessageDigest;
+import java.security.NoSuchAlgorithmException;
+import java.util.ArrayList;
+import java.util.Collections;
+import java.util.LinkedList;
+import java.util.List;
+
+public class NumericFingerprintGenerator implements FingerprintGenerator {
+
+  private static final int FINGERPRINT_VERSION = 0;
+
+  private final int iterations;
+
+  /**
+   * Construct a fingerprint generator for 60 digit numerics.
+   *
+   * @param iterations The number of internal iterations to perform in the process of
+   *                   generating a fingerprint. This needs to be constant, and synchronized
+   *                   across all clients.
+   *
+   *                   The higher the iteration count, the higher the security level:
+   *
+   *                   - 1024 ~ 109.7 bits
+   *                   - 1400 > 110 bits
+   *                   - 5200 > 112 bits
+   */
+  public NumericFingerprintGenerator(int iterations) {
+    this.iterations = iterations;
+  }
+
+  /**
+   * Generate a scannable and displayable fingerprint.
+   *
+   * @param version The version of fingerprint you are generating.
+   * @param localStableIdentifier The client's "stable" identifier.
+   * @param localIdentityKey The client's identity key.
+   * @param remoteStableIdentifier The remote party's "stable" identifier.
+   * @param remoteIdentityKey The remote party's identity key.
+   * @return A unique fingerprint for this conversation.
+   */
+  @Override
+  public Fingerprint createFor(int version,
+                               byte[] localStableIdentifier,
+                               final IdentityKey localIdentityKey,
+                               byte[] remoteStableIdentifier,
+                               final IdentityKey remoteIdentityKey)
+  {
+    return createFor(version,
+                     localStableIdentifier,
+                     new LinkedList<IdentityKey>() {{
+                       add(localIdentityKey);
+                     }},
+                     remoteStableIdentifier,
+                     new LinkedList<IdentityKey>() {{
+                       add(remoteIdentityKey);
+                     }});
+  }
+
+  /**
+   * Generate a scannable and displayable fingerprint for logical identities that have multiple
+   * physical keys.
+   *
+   * Do not trust the output of this unless you've been through the device consistency process
+   * for the provided localIdentityKeys.
+   *
+   * @param version The version of fingerprint you are generating.
+   * @param localStableIdentifier The client's "stable" identifier.
+   * @param localIdentityKeys The client's collection of physical identity keys.
+   * @param remoteStableIdentifier The remote party's "stable" identifier.
+   * @param remoteIdentityKeys The remote party's collection of physical identity key.
+   * @return A unique fingerprint for this conversation.
+   */
+  public Fingerprint createFor(int version,
+                               byte[] localStableIdentifier,
+                               List<IdentityKey> localIdentityKeys,
+                               byte[] remoteStableIdentifier,
+                               List<IdentityKey> remoteIdentityKeys)
+  {
+    byte[] localFingerprint  = getFingerprint(iterations, localStableIdentifier, localIdentityKeys);
+    byte[] remoteFingerprint = getFingerprint(iterations, remoteStableIdentifier, remoteIdentityKeys);
+
+    DisplayableFingerprint displayableFingerprint = new DisplayableFingerprint(localFingerprint,
+                                                                               remoteFingerprint);
+
+    ScannableFingerprint   scannableFingerprint   = new ScannableFingerprint(version,
+                                                                             localFingerprint,
+                                                                             remoteFingerprint);
+
+    return new Fingerprint(displayableFingerprint, scannableFingerprint);
+  }
+
+  private byte[] getFingerprint(int iterations, byte[] stableIdentifier, List<IdentityKey> unsortedIdentityKeys) {
+    try {
+      MessageDigest digest    = MessageDigest.getInstance("SHA-512");
+      byte[]        publicKey = getLogicalKeyBytes(unsortedIdentityKeys);
+      byte[]        hash      = ByteUtil.combine(ByteUtil.shortToByteArray(FINGERPRINT_VERSION),
+                                                 publicKey, stableIdentifier);
+
+      for (int i=0;i<iterations;i++) {
+        digest.update(hash);
+        hash = digest.digest(publicKey);
+      }
+
+      return hash;
+    } catch (NoSuchAlgorithmException e) {
+      throw new AssertionError(e);
+    }
+  }
+
+  private byte[] getLogicalKeyBytes(List<IdentityKey> identityKeys) {
+    ArrayList<IdentityKey> sortedIdentityKeys = new ArrayList<>(identityKeys);
+    Collections.sort(sortedIdentityKeys, new IdentityKeyComparator());
+
+    ByteArrayOutputStream baos = new ByteArrayOutputStream();
+
+    for (IdentityKey identityKey : sortedIdentityKeys) {
+      byte[] publicKeyBytes = identityKey.getPublicKey().serialize();
+      baos.write(publicKeyBytes, 0, publicKeyBytes.length);
+    }
+
+    return baos.toByteArray();
+  }
+
+
+}

java/src/main/java/org/whispersystems/libsignal/fingerprint/ScannableFingerprint.java

@@ -0,0 +1,73 @@
+/**
+ * Copyright (C) 2016 Open Whisper Systems
+ *
+ * Licensed according to the LICENSE file in this repository.
+ */
+package org.whispersystems.libsignal.fingerprint;
+
+import com.google.protobuf.ByteString;
+import com.google.protobuf.InvalidProtocolBufferException;
+
+import org.whispersystems.libsignal.fingerprint.FingerprintProtos.CombinedFingerprints;
+import org.whispersystems.libsignal.fingerprint.FingerprintProtos.LogicalFingerprint;
+import org.whispersystems.libsignal.util.ByteUtil;
+
+import java.security.MessageDigest;
+
+public class ScannableFingerprint {
+
+  private final int                  version;
+  private final CombinedFingerprints fingerprints;
+
+  ScannableFingerprint(int version, byte[] localFingerprintData, byte[] remoteFingerprintData)
+  {
+    LogicalFingerprint localFingerprint = LogicalFingerprint.newBuilder()
+                                                            .setContent(ByteString.copyFrom(ByteUtil.trim(localFingerprintData, 32)))
+                                                            .build();
+
+    LogicalFingerprint remoteFingerprint = LogicalFingerprint.newBuilder()
+                                                             .setContent(ByteString.copyFrom(ByteUtil.trim(remoteFingerprintData, 32)))
+                                                             .build();
+
+    this.version      = version;
+    this.fingerprints = CombinedFingerprints.newBuilder()
+                                            .setVersion(version)
+                                            .setLocalFingerprint(localFingerprint)
+                                            .setRemoteFingerprint(remoteFingerprint)
+                                            .build();
+  }
+
+  /**
+   * @return A byte string to be displayed in a QR code.
+   */
+  public byte[] getSerialized() {
+    return fingerprints.toByteArray();
+  }
+
+  /**
+   * Compare a scanned QR code with what we expect.
+   *
+   * @param scannedFingerprintData The scanned data
+   * @return True if matching, otherwise false.
+   * @throws FingerprintVersionMismatchException if the scanned fingerprint is the wrong version.
+   */
+  public boolean compareTo(byte[] scannedFingerprintData)
+      throws FingerprintVersionMismatchException,
+             FingerprintParsingException
+  {
+    try {
+      CombinedFingerprints scanned = CombinedFingerprints.parseFrom(scannedFingerprintData);
+
+      if (!scanned.hasRemoteFingerprint() || !scanned.hasLocalFingerprint() ||
+          !scanned.hasVersion() || scanned.getVersion() != version)
+      {
+        throw new FingerprintVersionMismatchException(scanned.getVersion(), version);
+      }
+
+      return MessageDigest.isEqual(fingerprints.getLocalFingerprint().getContent().toByteArray(), scanned.getRemoteFingerprint().getContent().toByteArray()) &&
+             MessageDigest.isEqual(fingerprints.getRemoteFingerprint().getContent().toByteArray(), scanned.getLocalFingerprint().getContent().toByteArray());
+    } catch (InvalidProtocolBufferException e) {
+      throw new FingerprintParsingException(e);
+    }
+  }
+}

java/src/main/java/org/whispersystems/libsignal/groups/GroupCipher.java

@@ -1,33 +1,22 @@
 /**
- * Copyright (C) 2014-2015 Open Whisper Systems
+ * Copyright (C) 2014-2016 Open Whisper Systems
  *
- * This program is free software: you can redistribute it and/or modify
- * it under the terms of the GNU General Public License as published by
- * the Free Software Foundation, either version 3 of the License, or
- * (at your option) any later version.
- *
- * This program is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
- * GNU General Public License for more details.
- *
- * You should have received a copy of the GNU General Public License
- * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ * Licensed according to the LICENSE file in this repository.
  */
-package org.whispersystems.libaxolotl.groups;
+package org.whispersystems.libsignal.groups;
 
-import org.whispersystems.libaxolotl.DecryptionCallback;
-import org.whispersystems.libaxolotl.DuplicateMessageException;
-import org.whispersystems.libaxolotl.InvalidKeyIdException;
-import org.whispersystems.libaxolotl.InvalidMessageException;
-import org.whispersystems.libaxolotl.LegacyMessageException;
-import org.whispersystems.libaxolotl.NoSessionException;
-import org.whispersystems.libaxolotl.groups.ratchet.SenderChainKey;
-import org.whispersystems.libaxolotl.groups.ratchet.SenderMessageKey;
-import org.whispersystems.libaxolotl.groups.state.SenderKeyRecord;
-import org.whispersystems.libaxolotl.groups.state.SenderKeyState;
-import org.whispersystems.libaxolotl.groups.state.SenderKeyStore;
-import org.whispersystems.libaxolotl.protocol.SenderKeyMessage;
+import org.whispersystems.libsignal.DecryptionCallback;
+import org.whispersystems.libsignal.DuplicateMessageException;
+import org.whispersystems.libsignal.InvalidKeyIdException;
+import org.whispersystems.libsignal.InvalidMessageException;
+import org.whispersystems.libsignal.LegacyMessageException;
+import org.whispersystems.libsignal.NoSessionException;
+import org.whispersystems.libsignal.groups.ratchet.SenderChainKey;
+import org.whispersystems.libsignal.groups.ratchet.SenderMessageKey;
+import org.whispersystems.libsignal.groups.state.SenderKeyRecord;
+import org.whispersystems.libsignal.groups.state.SenderKeyState;
+import org.whispersystems.libsignal.groups.state.SenderKeyStore;
+import org.whispersystems.libsignal.protocol.SenderKeyMessage;
 
 import java.security.InvalidAlgorithmParameterException;
 import java.security.NoSuchAlgorithmException;
@@ -40,10 +29,10 @@ import javax.crypto.spec.IvParameterSpec;
 import javax.crypto.spec.SecretKeySpec;
 
 /**
- * The main entry point for axolotl group encrypt/decrypt operations.
+ * The main entry point for Signal Protocol group encrypt/decrypt operations.
  *
- * Once a session has been established with {@link org.whispersystems.libaxolotl.groups.GroupSessionBuilder}
- * and a {@link org.whispersystems.libaxolotl.protocol.SenderKeyDistributionMessage} has been
+ * Once a session has been established with {@link org.whispersystems.libsignal.groups.GroupSessionBuilder}
+ * and a {@link org.whispersystems.libsignal.protocol.SenderKeyDistributionMessage} has been
  * distributed to each member of the group, this class can be used for all subsequent encrypt/decrypt
  * operations within that session (ie: until group membership changes).
  *
@@ -148,7 +137,7 @@ public class GroupCipher {
         senderKeyStore.storeSenderKey(senderKeyId, record);
 
         return plaintext;
-      } catch (org.whispersystems.libaxolotl.InvalidKeyException | InvalidKeyIdException e) {
+      } catch (org.whispersystems.libsignal.InvalidKeyException | InvalidKeyIdException e) {
         throw new InvalidMessageException(e);
       }
     }

java/src/main/java/org/whispersystems/libsignal/groups/GroupSessionBuilder.java

@@ -1,33 +1,22 @@
 /**
- * Copyright (C) 2014-2015 Open Whisper Systems
+ * Copyright (C) 2014-2016 Open Whisper Systems
  *
- * This program is free software: you can redistribute it and/or modify
- * it under the terms of the GNU General Public License as published by
- * the Free Software Foundation, either version 3 of the License, or
- * (at your option) any later version.
- *
- * This program is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
- * GNU General Public License for more details.
- *
- * You should have received a copy of the GNU General Public License
- * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ * Licensed according to the LICENSE file in this repository.
  */
-package org.whispersystems.libaxolotl.groups;
+package org.whispersystems.libsignal.groups;
 
-import org.whispersystems.libaxolotl.InvalidKeyException;
-import org.whispersystems.libaxolotl.InvalidKeyIdException;
-import org.whispersystems.libaxolotl.groups.state.SenderKeyRecord;
-import org.whispersystems.libaxolotl.groups.state.SenderKeyState;
-import org.whispersystems.libaxolotl.groups.state.SenderKeyStore;
-import org.whispersystems.libaxolotl.protocol.SenderKeyDistributionMessage;
-import org.whispersystems.libaxolotl.util.KeyHelper;
+import org.whispersystems.libsignal.InvalidKeyException;
+import org.whispersystems.libsignal.InvalidKeyIdException;
+import org.whispersystems.libsignal.groups.state.SenderKeyRecord;
+import org.whispersystems.libsignal.groups.state.SenderKeyState;
+import org.whispersystems.libsignal.groups.state.SenderKeyStore;
+import org.whispersystems.libsignal.protocol.SenderKeyDistributionMessage;
+import org.whispersystems.libsignal.util.KeyHelper;
 
 /**
  * GroupSessionBuilder is responsible for setting up group SenderKey encrypted sessions.
  *
- * Once a session has been established, {@link org.whispersystems.libaxolotl.groups.GroupCipher}
+ * Once a session has been established, {@link org.whispersystems.libsignal.groups.GroupCipher}
  * can be used to encrypt/decrypt messages in that session.
  * <p>
  * The built sessions are unidirectional: they can be used either for sending or for receiving,

java/src/main/java/org/whispersystems/libsignal/groups/SenderKeyName.java

@@ -0,0 +1,52 @@
+/**
+ * Copyright (C) 2014-2016 Open Whisper Systems
+ *
+ * Licensed according to the LICENSE file in this repository.
+ */
+package org.whispersystems.libsignal.groups;
+
+import org.whispersystems.libsignal.SignalProtocolAddress;
+
+/**
+ * A representation of a (groupId + senderId + deviceId) tuple.
+ */
+public class SenderKeyName {
+
+  private final String                groupId;
+  private final SignalProtocolAddress sender;
+
+  public SenderKeyName(String groupId, SignalProtocolAddress sender) {
+    this.groupId  = groupId;
+    this.sender   = sender;
+  }
+
+  public String getGroupId() {
+    return groupId;
+  }
+
+  public SignalProtocolAddress getSender() {
+    return sender;
+  }
+
+  public String serialize() {
+    return groupId + "::" + sender.getName() + "::" + String.valueOf(sender.getDeviceId());
+  }
+
+  @Override
+  public boolean equals(Object other) {
+    if (other == null)                     return false;
+    if (!(other instanceof SenderKeyName)) return false;
+
+    SenderKeyName that = (SenderKeyName)other;
+
+    return
+        this.groupId.equals(that.groupId) &&
+        this.sender.equals(that.sender);
+  }
+
+  @Override
+  public int hashCode() {
+    return this.groupId.hashCode() ^ this.sender.hashCode();
+  }
+
+}

java/src/main/java/org/whispersystems/libsignal/groups/ratchet/SenderChainKey.java

@@ -1,20 +1,9 @@
 /**
- * Copyright (C) 2014-2015 Open Whisper Systems
+ * Copyright (C) 2014-2016 Open Whisper Systems
  *
- * This program is free software: you can redistribute it and/or modify
- * it under the terms of the GNU General Public License as published by
- * the Free Software Foundation, either version 3 of the License, or
- * (at your option) any later version.
- *
- * This program is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
- * GNU General Public License for more details.
- *
- * You should have received a copy of the GNU General Public License
- * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ * Licensed according to the LICENSE file in this repository.
  */
-package org.whispersystems.libaxolotl.groups.ratchet;
+package org.whispersystems.libsignal.groups.ratchet;
 
 import java.security.InvalidKeyException;
 import java.security.NoSuchAlgorithmException;

java/src/main/java/org/whispersystems/libsignal/groups/ratchet/SenderMessageKey.java

@@ -1,24 +1,13 @@
 /**
- * Copyright (C) 2014-2015 Open Whisper Systems
+ * Copyright (C) 2014-2016 Open Whisper Systems
  *
- * This program is free software: you can redistribute it and/or modify
- * it under the terms of the GNU General Public License as published by
- * the Free Software Foundation, either version 3 of the License, or
- * (at your option) any later version.
- *
- * This program is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
- * GNU General Public License for more details.
- *
- * You should have received a copy of the GNU General Public License
- * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ * Licensed according to the LICENSE file in this repository.
  */
 
-package org.whispersystems.libaxolotl.groups.ratchet;
+package org.whispersystems.libsignal.groups.ratchet;
 
-import org.whispersystems.libaxolotl.kdf.HKDFv3;
-import org.whispersystems.libaxolotl.util.ByteUtil;
+import org.whispersystems.libsignal.kdf.HKDFv3;
+import org.whispersystems.libsignal.util.ByteUtil;
 
 /**
  * The final symmetric material (IV and Cipher Key) used for encrypting

java/src/main/java/org/whispersystems/libsignal/groups/state/SenderKeyRecord.java

@@ -1,37 +1,26 @@
 /**
- * Copyright (C) 2014-2015 Open Whisper Systems
+ * Copyright (C) 2014-2016 Open Whisper Systems
  *
- * This program is free software: you can redistribute it and/or modify
- * it under the terms of the GNU General Public License as published by
- * the Free Software Foundation, either version 3 of the License, or
- * (at your option) any later version.
- *
- * This program is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
- * GNU General Public License for more details.
- *
- * You should have received a copy of the GNU General Public License
- * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ * Licensed according to the LICENSE file in this repository.
  */
-package org.whispersystems.libaxolotl.groups.state;
+package org.whispersystems.libsignal.groups.state;
 
-import org.whispersystems.libaxolotl.InvalidKeyIdException;
-import org.whispersystems.libaxolotl.ecc.ECKeyPair;
-import org.whispersystems.libaxolotl.ecc.ECPublicKey;
-import org.whispersystems.libaxolotl.state.StorageProtos;
+import org.whispersystems.libsignal.InvalidKeyIdException;
+import org.whispersystems.libsignal.ecc.ECKeyPair;
+import org.whispersystems.libsignal.ecc.ECPublicKey;
+import org.whispersystems.libsignal.state.StorageProtos;
 
 import java.io.IOException;
 import java.util.LinkedList;
 import java.util.List;
 
-import static org.whispersystems.libaxolotl.state.StorageProtos.SenderKeyRecordStructure;
+import static org.whispersystems.libsignal.state.StorageProtos.SenderKeyRecordStructure;
 
 /**
  * A durable representation of a set of SenderKeyStates for a specific
  * SenderKeyName.
  *
- * @author Moxie Marlisnpike
+ * @author Moxie Marlinspike
  */
 public class SenderKeyRecord {
 

java/src/main/java/org/whispersystems/libsignal/groups/state/SenderKeyState.java

@@ -1,37 +1,26 @@
 /**
- * Copyright (C) 2014-2015 Open Whisper Systems
+ * Copyright (C) 2014-2016 Open Whisper Systems
  *
- * This program is free software: you can redistribute it and/or modify
- * it under the terms of the GNU General Public License as published by
- * the Free Software Foundation, either version 3 of the License, or
- * (at your option) any later version.
- *
- * This program is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
- * GNU General Public License for more details.
- *
- * You should have received a copy of the GNU General Public License
- * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ * Licensed according to the LICENSE file in this repository.
  */
-package org.whispersystems.libaxolotl.groups.state;
+package org.whispersystems.libsignal.groups.state;
 
 import com.google.protobuf.ByteString;
 
-import org.whispersystems.libaxolotl.InvalidKeyException;
-import org.whispersystems.libaxolotl.ecc.Curve;
-import org.whispersystems.libaxolotl.ecc.ECKeyPair;
-import org.whispersystems.libaxolotl.ecc.ECPrivateKey;
-import org.whispersystems.libaxolotl.ecc.ECPublicKey;
-import org.whispersystems.libaxolotl.groups.ratchet.SenderChainKey;
-import org.whispersystems.libaxolotl.groups.ratchet.SenderMessageKey;
-import org.whispersystems.libaxolotl.util.guava.Optional;
+import org.whispersystems.libsignal.InvalidKeyException;
+import org.whispersystems.libsignal.ecc.Curve;
+import org.whispersystems.libsignal.ecc.ECKeyPair;
+import org.whispersystems.libsignal.ecc.ECPrivateKey;
+import org.whispersystems.libsignal.ecc.ECPublicKey;
+import org.whispersystems.libsignal.groups.ratchet.SenderChainKey;
+import org.whispersystems.libsignal.groups.ratchet.SenderMessageKey;
+import org.whispersystems.libsignal.util.guava.Optional;
 
 import java.util.Iterator;
 import java.util.LinkedList;
 import java.util.List;
 
-import static org.whispersystems.libaxolotl.state.StorageProtos.SenderKeyStateStructure;
+import static org.whispersystems.libsignal.state.StorageProtos.SenderKeyStateStructure;
 
 /**
  * Represents the state of an individual SenderKey ratchet.

java/src/main/java/org/whispersystems/libsignal/groups/state/SenderKeyStore.java

@@ -1,27 +1,16 @@
 /**
- * Copyright (C) 2014-2015 Open Whisper Systems
+ * Copyright (C) 2014-2016 Open Whisper Systems
  *
- * This program is free software: you can redistribute it and/or modify
- * it under the terms of the GNU General Public License as published by
- * the Free Software Foundation, either version 3 of the License, or
- * (at your option) any later version.
- *
- * This program is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
- * GNU General Public License for more details.
- *
- * You should have received a copy of the GNU General Public License
- * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ * Licensed according to the LICENSE file in this repository.
  */
-package org.whispersystems.libaxolotl.groups.state;
+package org.whispersystems.libsignal.groups.state;
 
-import org.whispersystems.libaxolotl.groups.SenderKeyName;
+import org.whispersystems.libsignal.groups.SenderKeyName;
 
 public interface SenderKeyStore {
 
   /**
-   * Commit to storage the {@link org.whispersystems.libaxolotl.groups.state.SenderKeyRecord} for a
+   * Commit to storage the {@link org.whispersystems.libsignal.groups.state.SenderKeyRecord} for a
    * given (groupId + senderId + deviceId) tuple.
    *
    * @param senderKeyName the (groupId + senderId + deviceId) tuple.
@@ -30,7 +19,7 @@ public interface SenderKeyStore {
   public void storeSenderKey(SenderKeyName senderKeyName, SenderKeyRecord record);
 
   /**
-   * Returns a copy of the {@link org.whispersystems.libaxolotl.groups.state.SenderKeyRecord}
+   * Returns a copy of the {@link org.whispersystems.libsignal.groups.state.SenderKeyRecord}
    * corresponding to the (groupId + senderId + deviceId) tuple, or a new SenderKeyRecord if
    * one does not currently exist.
    * <p>

java/src/main/java/org/whispersystems/libsignal/kdf/DerivedMessageSecrets.java

@@ -1,23 +1,12 @@
 /**
- * Copyright (C) 2014 Open Whisper Systems
+ * Copyright (C) 2014-2016 Open Whisper Systems
  *
- * This program is free software: you can redistribute it and/or modify
- * it under the terms of the GNU General Public License as published by
- * the Free Software Foundation, either version 3 of the License, or
- * (at your option) any later version.
- *
- * This program is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
- * GNU General Public License for more details.
- *
- * You should have received a copy of the GNU General Public License
- * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ * Licensed according to the LICENSE file in this repository.
  */
 
-package org.whispersystems.libaxolotl.kdf;
+package org.whispersystems.libsignal.kdf;
 
-import org.whispersystems.libaxolotl.util.ByteUtil;
+import org.whispersystems.libsignal.util.ByteUtil;
 
 import java.text.ParseException;
 

java/src/main/java/org/whispersystems/libsignal/kdf/DerivedRootSecrets.java

@@ -1,6 +1,11 @@
-package org.whispersystems.libaxolotl.kdf;
+/**
+ * Copyright (C) 2014-2016 Open Whisper Systems
+ *
+ * Licensed according to the LICENSE file in this repository.
+ */
+package org.whispersystems.libsignal.kdf;
 
-import org.whispersystems.libaxolotl.util.ByteUtil;
+import org.whispersystems.libsignal.util.ByteUtil;
 
 public class DerivedRootSecrets {
 

java/src/main/java/org/whispersystems/libsignal/kdf/HKDF.java

@@ -1,21 +1,10 @@
 /**
- * Copyright (C) 2013 Open Whisper Systems
+ * Copyright (C) 2013-2016 Open Whisper Systems
  *
- * This program is free software: you can redistribute it and/or modify
- * it under the terms of the GNU General Public License as published by
- * the Free Software Foundation, either version 3 of the License, or
- * (at your option) any later version.
- *
- * This program is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
- * GNU General Public License for more details.
- *
- * You should have received a copy of the GNU General Public License
- * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ * Licensed according to the LICENSE file in this repository.
  */
 
-package org.whispersystems.libaxolotl.kdf;
+package org.whispersystems.libsignal.kdf;
 
 import java.io.ByteArrayOutputStream;
 import java.security.InvalidKeyException;

java/src/main/java/org/whispersystems/libsignal/kdf/HKDFv2.java

@@ -0,0 +1,13 @@
+/**
+ * Copyright (C) 2014-2016 Open Whisper Systems
+ *
+ * Licensed according to the LICENSE file in this repository.
+ */
+package org.whispersystems.libsignal.kdf;
+
+public class HKDFv2 extends HKDF {
+  @Override
+  protected int getIterationStartOffset() {
+    return 0;
+  }
+}

java/src/main/java/org/whispersystems/libsignal/kdf/HKDFv3.java

@@ -0,0 +1,13 @@
+/**
+ * Copyright (C) 2014-2016 Open Whisper Systems
+ *
+ * Licensed according to the LICENSE file in this repository.
+ */
+package org.whispersystems.libsignal.kdf;
+
+public class HKDFv3 extends HKDF {
+  @Override
+  protected int getIterationStartOffset() {
+    return 1;
+  }
+}

java/src/main/java/org/whispersystems/libsignal/logging/Log.java

@@ -1,4 +1,9 @@
-package org.whispersystems.libaxolotl.logging;
+/**
+ * Copyright (C) 2014-2016 Open Whisper Systems
+ *
+ * Licensed according to the LICENSE file in this repository.
+ */
+package org.whispersystems.libsignal.logging;
 
 import java.io.PrintWriter;
 import java.io.StringWriter;
@@ -9,47 +14,47 @@ public class Log {
   private Log() {}
 
   public static void v(String tag, String msg) {
-    log(AxolotlLogger.VERBOSE, tag, msg);
+    log(SignalProtocolLogger.VERBOSE, tag, msg);
   }
 
   public static void v(String tag, String msg, Throwable tr) {
-    log(AxolotlLogger.VERBOSE, tag, msg + '\n' + getStackTraceString(tr));
+    log(SignalProtocolLogger.VERBOSE, tag, msg + '\n' + getStackTraceString(tr));
   }
 
   public static void d(String tag, String msg) {
-    log(AxolotlLogger.DEBUG, tag, msg);
+    log(SignalProtocolLogger.DEBUG, tag, msg);
   }
 
   public static void d(String tag, String msg, Throwable tr) {
-    log(AxolotlLogger.DEBUG, tag, msg + '\n' + getStackTraceString(tr));
+    log(SignalProtocolLogger.DEBUG, tag, msg + '\n' + getStackTraceString(tr));
   }
 
   public static void i(String tag, String msg) {
-    log(AxolotlLogger.INFO, tag, msg);
+    log(SignalProtocolLogger.INFO, tag, msg);
   }
 
   public static void i(String tag, String msg, Throwable tr) {
-    log(AxolotlLogger.INFO, tag, msg + '\n' + getStackTraceString(tr));
+    log(SignalProtocolLogger.INFO, tag, msg + '\n' + getStackTraceString(tr));
   }
 
   public static void w(String tag, String msg) {
-    log(AxolotlLogger.WARN, tag, msg);
+    log(SignalProtocolLogger.WARN, tag, msg);
   }
 
   public static void w(String tag, String msg, Throwable tr) {
-    log(AxolotlLogger.WARN, tag, msg + '\n' + getStackTraceString(tr));
+    log(SignalProtocolLogger.WARN, tag, msg + '\n' + getStackTraceString(tr));
   }
 
   public static void w(String tag, Throwable tr) {
-    log(AxolotlLogger.WARN, tag, getStackTraceString(tr));
+    log(SignalProtocolLogger.WARN, tag, getStackTraceString(tr));
   }
 
   public static void e(String tag, String msg) {
-    log(AxolotlLogger.ERROR, tag, msg);
+    log(SignalProtocolLogger.ERROR, tag, msg);
   }
 
   public static void e(String tag, String msg, Throwable tr) {
-    log(AxolotlLogger.ERROR, tag, msg + '\n' + getStackTraceString(tr));
+    log(SignalProtocolLogger.ERROR, tag, msg + '\n' + getStackTraceString(tr));
   }
 
   private static String getStackTraceString(Throwable tr) {
@@ -75,7 +80,7 @@ public class Log {
   }
 
   private static void log(int priority, String tag, String msg) {
-    AxolotlLogger logger = AxolotlLoggerProvider.getProvider();
+    SignalProtocolLogger logger = SignalProtocolLoggerProvider.getProvider();
 
     if (logger != null) {
       logger.log(priority, tag, msg);

java/src/main/java/org/whispersystems/libsignal/logging/SignalProtocolLogger.java

@@ -1,6 +1,11 @@
-package org.whispersystems.libaxolotl.logging;
+/**
+ * Copyright (C) 2014-2016 Open Whisper Systems
+ *
+ * Licensed according to the LICENSE file in this repository.
+ */
+package org.whispersystems.libsignal.logging;
 
-public interface AxolotlLogger {
+public interface SignalProtocolLogger {
 
   public static final int VERBOSE = 2;
   public static final int DEBUG   = 3;

java/src/main/java/org/whispersystems/libsignal/logging/SignalProtocolLoggerProvider.java

@@ -0,0 +1,19 @@
+/**
+ * Copyright (C) 2014-2016 Open Whisper Systems
+ *
+ * Licensed according to the LICENSE file in this repository.
+ */
+package org.whispersystems.libsignal.logging;
+
+public class SignalProtocolLoggerProvider {
+
+  private static SignalProtocolLogger provider;
+
+  public static SignalProtocolLogger getProvider() {
+    return provider;
+  }
+
+  public static void setProvider(SignalProtocolLogger provider) {
+    SignalProtocolLoggerProvider.provider = provider;
+  }
+}

java/src/main/java/org/whispersystems/libsignal/protocol/CiphertextMessage.java

@@ -0,0 +1,23 @@
+/**
+ * Copyright (C) 2014-2016 Open Whisper Systems
+ *
+ * Licensed according to the LICENSE file in this repository.
+ */
+package org.whispersystems.libsignal.protocol;
+
+public interface CiphertextMessage {
+
+  public static final int CURRENT_VERSION     = 3;
+
+  public static final int WHISPER_TYPE                = 2;
+  public static final int PREKEY_TYPE                 = 3;
+  public static final int SENDERKEY_TYPE              = 4;
+  public static final int SENDERKEY_DISTRIBUTION_TYPE = 5;
+
+  // This should be the worst case (worse than V2).  So not always accurate, but good enough for padding.
+  public static final int ENCRYPTED_MESSAGE_OVERHEAD = 53;
+
+  public byte[] serialize();
+  public int getType();
+
+}

java/src/main/java/org/whispersystems/libsignal/protocol/DeviceConsistencyMessage.java

@@ -0,0 +1,62 @@
+package org.whispersystems.libsignal.protocol;
+
+import com.google.protobuf.ByteString;
+import com.google.protobuf.InvalidProtocolBufferException;
+
+import org.whispersystems.curve25519.VrfSignatureVerificationFailedException;
+import org.whispersystems.libsignal.IdentityKey;
+import org.whispersystems.libsignal.IdentityKeyPair;
+import org.whispersystems.libsignal.InvalidKeyException;
+import org.whispersystems.libsignal.InvalidMessageException;
+import org.whispersystems.libsignal.devices.DeviceConsistencyCommitment;
+import org.whispersystems.libsignal.devices.DeviceConsistencySignature;
+import org.whispersystems.libsignal.ecc.Curve;
+
+public class DeviceConsistencyMessage {
+
+  private final DeviceConsistencySignature  signature;
+  private final int                         generation;
+  private final byte[]                      serialized;
+
+  public DeviceConsistencyMessage(DeviceConsistencyCommitment commitment, IdentityKeyPair identityKeyPair) {
+    try {
+      byte[] signatureBytes = Curve.calculateVrfSignature(identityKeyPair.getPrivateKey(), commitment.toByteArray());
+      byte[] vrfOutputBytes = Curve.verifyVrfSignature(identityKeyPair.getPublicKey().getPublicKey(), commitment.toByteArray(), signatureBytes);
+
+      this.generation = commitment.getGeneration();
+      this.signature  = new DeviceConsistencySignature(signatureBytes, vrfOutputBytes);
+      this.serialized = SignalProtos.DeviceConsistencyCodeMessage.newBuilder()
+                                                                  .setGeneration(commitment.getGeneration())
+                                                                  .setSignature(ByteString.copyFrom(signature.getSignature()))
+                                                                  .build()
+                                                                  .toByteArray();
+    } catch (InvalidKeyException | VrfSignatureVerificationFailedException e) {
+      throw new AssertionError(e);
+    }
+  }
+
+  public DeviceConsistencyMessage(DeviceConsistencyCommitment commitment, byte[] serialized, IdentityKey identityKey) throws InvalidMessageException {
+    try {
+      SignalProtos.DeviceConsistencyCodeMessage message = SignalProtos.DeviceConsistencyCodeMessage.parseFrom(serialized);
+      byte[] vrfOutputBytes = Curve.verifyVrfSignature(identityKey.getPublicKey(), commitment.toByteArray(), message.getSignature().toByteArray());
+
+      this.generation = message.getGeneration();
+      this.signature  = new DeviceConsistencySignature(message.getSignature().toByteArray(), vrfOutputBytes);
+      this.serialized = serialized;
+    } catch (InvalidProtocolBufferException | InvalidKeyException | VrfSignatureVerificationFailedException e) {
+      throw new InvalidMessageException(e);
+    }
+  }
+
+  public byte[] getSerialized() {
+    return serialized;
+  }
+
+  public DeviceConsistencySignature getSignature() {
+    return signature;
+  }
+
+  public int getGeneration() {
+    return generation;
+  }
+}

java/src/main/java/org/whispersystems/libsignal/protocol/PreKeySignalMessage.java

@@ -0,0 +1,139 @@
+/**
+ * Copyright (C) 2014-2016 Open Whisper Systems
+ *
+ * Licensed according to the LICENSE file in this repository.
+ */
+package org.whispersystems.libsignal.protocol;
+
+import com.google.protobuf.ByteString;
+import com.google.protobuf.InvalidProtocolBufferException;
+
+import org.whispersystems.libsignal.IdentityKey;
+import org.whispersystems.libsignal.InvalidKeyException;
+import org.whispersystems.libsignal.InvalidMessageException;
+import org.whispersystems.libsignal.InvalidVersionException;
+import org.whispersystems.libsignal.LegacyMessageException;
+import org.whispersystems.libsignal.ecc.Curve;
+import org.whispersystems.libsignal.ecc.ECPublicKey;
+import org.whispersystems.libsignal.util.ByteUtil;
+import org.whispersystems.libsignal.util.guava.Optional;
+
+
+public class PreKeySignalMessage implements CiphertextMessage {
+
+  private final int               version;
+  private final int               registrationId;
+  private final Optional<Integer> preKeyId;
+  private final int               signedPreKeyId;
+  private final ECPublicKey       baseKey;
+  private final IdentityKey       identityKey;
+  private final SignalMessage     message;
+  private final byte[]            serialized;
+
+  public PreKeySignalMessage(byte[] serialized)
+      throws InvalidMessageException, InvalidVersionException
+  {
+    try {
+      this.version = ByteUtil.highBitsToInt(serialized[0]);
+
+      if (this.version > CiphertextMessage.CURRENT_VERSION) {
+        throw new InvalidVersionException("Unknown version: " + this.version);
+      }
+
+      if (this.version < CiphertextMessage.CURRENT_VERSION) {
+        throw new LegacyMessageException("Legacy version: " + this.version);
+      }
+
+      SignalProtos.PreKeySignalMessage preKeyWhisperMessage
+          = SignalProtos.PreKeySignalMessage.parseFrom(ByteString.copyFrom(serialized, 1,
+                                                                           serialized.length-1));
+
+      if (!preKeyWhisperMessage.hasSignedPreKeyId()  ||
+          !preKeyWhisperMessage.hasBaseKey()         ||
+          !preKeyWhisperMessage.hasIdentityKey()     ||
+          !preKeyWhisperMessage.hasMessage())
+      {
+        throw new InvalidMessageException("Incomplete message.");
+      }
+
+      this.serialized     = serialized;
+      this.registrationId = preKeyWhisperMessage.getRegistrationId();
+      this.preKeyId       = preKeyWhisperMessage.hasPreKeyId() ? Optional.of(preKeyWhisperMessage.getPreKeyId()) : Optional.<Integer>absent();
+      this.signedPreKeyId = preKeyWhisperMessage.hasSignedPreKeyId() ? preKeyWhisperMessage.getSignedPreKeyId() : -1;
+      this.baseKey        = Curve.decodePoint(preKeyWhisperMessage.getBaseKey().toByteArray(), 0);
+      this.identityKey    = new IdentityKey(Curve.decodePoint(preKeyWhisperMessage.getIdentityKey().toByteArray(), 0));
+      this.message        = new SignalMessage(preKeyWhisperMessage.getMessage().toByteArray());
+    } catch (InvalidProtocolBufferException | InvalidKeyException | LegacyMessageException e) {
+      throw new InvalidMessageException(e);
+    }
+  }
+
+  public PreKeySignalMessage(int messageVersion, int registrationId, Optional<Integer> preKeyId,
+                             int signedPreKeyId, ECPublicKey baseKey, IdentityKey identityKey,
+                             SignalMessage message)
+  {
+    this.version        = messageVersion;
+    this.registrationId = registrationId;
+    this.preKeyId       = preKeyId;
+    this.signedPreKeyId = signedPreKeyId;
+    this.baseKey        = baseKey;
+    this.identityKey    = identityKey;
+    this.message        = message;
+
+    SignalProtos.PreKeySignalMessage.Builder builder =
+        SignalProtos.PreKeySignalMessage.newBuilder()
+                                        .setSignedPreKeyId(signedPreKeyId)
+                                        .setBaseKey(ByteString.copyFrom(baseKey.serialize()))
+                                        .setIdentityKey(ByteString.copyFrom(identityKey.serialize()))
+                                        .setMessage(ByteString.copyFrom(message.serialize()))
+                                        .setRegistrationId(registrationId);
+
+    if (preKeyId.isPresent()) {
+      builder.setPreKeyId(preKeyId.get());
+    }
+
+    byte[] versionBytes = {ByteUtil.intsToByteHighAndLow(this.version, CURRENT_VERSION)};
+    byte[] messageBytes = builder.build().toByteArray();
+
+    this.serialized = ByteUtil.combine(versionBytes, messageBytes);
+  }
+
+  public int getMessageVersion() {
+    return version;
+  }
+
+  public IdentityKey getIdentityKey() {
+    return identityKey;
+  }
+
+  public int getRegistrationId() {
+    return registrationId;
+  }
+
+  public Optional<Integer> getPreKeyId() {
+    return preKeyId;
+  }
+
+  public int getSignedPreKeyId() {
+    return signedPreKeyId;
+  }
+
+  public ECPublicKey getBaseKey() {
+    return baseKey;
+  }
+
+  public SignalMessage getWhisperMessage() {
+    return message;
+  }
+
+  @Override
+  public byte[] serialize() {
+    return serialized;
+  }
+
+  @Override
+  public int getType() {
+    return CiphertextMessage.PREKEY_TYPE;
+  }
+
+}