Check for concurrent cache updates.

and display attachments as they arrive while ImageActivity is open.

.gitignore

@@ -9,15 +9,20 @@ Thumbs.db
 .DS_Store
 
 # Eclipse project files
-#.classpath
-#.project
+.classpath
+.project
+.settings
 
 # Local configuration file (sdk path, etc)
 local.properties
 
 # Android Studio
 .idea/*
+!.idea/runConfigurations/
 !.idea/codeStyleSettings.xml
+!.idea/codeStyles
 .gradle
 build/
+captures
 *.iml
+projectFilesBackup/

.gitlab-ci.yml

@@ -0,0 +1,33 @@
+image: briar/ci-image-android:latest
+
+stages:
+- test
+- check_reproducibility
+
+test:
+  stage: test
+  before_script:
+    - set -e
+    - export GRADLE_USER_HOME=$PWD/.gradle
+
+  cache:
+    paths:
+      - .gradle/wrapper
+      - .gradle/caches
+
+  script:
+    - ./gradlew --no-daemon -Djava.security.egd=file:/dev/urandom animalSnifferMain animalSnifferTest
+    - ./gradlew --no-daemon -Djava.security.egd=file:/dev/urandom check compileOfficialDebugAndroidTestSources compileScreenshotDebugAndroidTestSources
+
+  after_script:
+    # these file change every time but should not be cached
+    - rm -f $GRADLE_USER_HOME/caches/modules-2/modules-2.lock
+    - rm -fr $GRADLE_USER_HOME/caches/*/plugin-resolution/
+
+
+test_reproducible:
+  stage: check_reproducibility
+  script:
+    - "curl -X POST -F token=${RELEASE_CHECK_TOKEN} -F ref=master -F variables[RELEASE_TAG]=${CI_COMMIT_REF_NAME} https://code.briarproject.org/api/v4/projects/61/trigger/pipeline"
+  only:
+    - tags

.idea/codeStyleSettings.xml

@@ -31,6 +31,8 @@
           </value>
         </option>
         <option name="RIGHT_MARGIN" value="100" />
+        <option name="JD_ALIGN_PARAM_COMMENTS" value="false" />
+        <option name="JD_ALIGN_EXCEPTION_COMMENTS" value="false" />
         <AndroidXmlCodeStyleSettings>
           <option name="USE_CUSTOM_SETTINGS" value="true" />
         </AndroidXmlCodeStyleSettings>
@@ -68,6 +70,12 @@
         <XML>
           <option name="XML_LEGACY_SETTINGS_IMPORTED" value="true" />
         </XML>
+        <codeStyleSettings language="Groovy">
+          <indentOptions>
+            <option name="USE_TAB_CHARACTER" value="true" />
+            <option name="SMART_TABS" value="true" />
+          </indentOptions>
+        </codeStyleSettings>
         <codeStyleSettings language="JAVA">
           <option name="RIGHT_MARGIN" value="80" />
           <option name="ALIGN_MULTILINE_PARAMETERS" value="false" />

.idea/codeStyles/Project.xml

@@ -0,0 +1,194 @@
+<component name="ProjectCodeStyleConfiguration">
+  <code_scheme name="Project" version="173">
+    <AndroidXmlCodeStyleSettings>
+      <option name="ARRANGEMENT_SETTINGS_MIGRATED_TO_191" value="true" />
+    </AndroidXmlCodeStyleSettings>
+    <JavaCodeStyleSettings>
+      <option name="ANNOTATION_PARAMETER_WRAP" value="1" />
+      <option name="IMPORT_LAYOUT_TABLE">
+        <value>
+          <package name="android" withSubpackages="true" static="false" />
+          <emptyLine />
+          <package name="com" withSubpackages="true" static="false" />
+          <emptyLine />
+          <package name="junit" withSubpackages="true" static="false" />
+          <emptyLine />
+          <package name="net" withSubpackages="true" static="false" />
+          <emptyLine />
+          <package name="org" withSubpackages="true" static="false" />
+          <emptyLine />
+          <package name="java" withSubpackages="true" static="false" />
+          <emptyLine />
+          <package name="javax" withSubpackages="true" static="false" />
+          <emptyLine />
+          <package name="" withSubpackages="true" static="false" />
+          <emptyLine />
+          <package name="" withSubpackages="true" static="true" />
+          <emptyLine />
+        </value>
+      </option>
+      <option name="JD_ALIGN_PARAM_COMMENTS" value="false" />
+      <option name="JD_ALIGN_EXCEPTION_COMMENTS" value="false" />
+    </JavaCodeStyleSettings>
+    <JetCodeStyleSettings>
+      <option name="CODE_STYLE_DEFAULTS" value="KOTLIN_OFFICIAL" />
+    </JetCodeStyleSettings>
+    <XML>
+      <option name="XML_LEGACY_SETTINGS_IMPORTED" value="true" />
+    </XML>
+    <codeStyleSettings language="Groovy">
+      <indentOptions>
+        <option name="USE_TAB_CHARACTER" value="true" />
+        <option name="SMART_TABS" value="true" />
+      </indentOptions>
+    </codeStyleSettings>
+    <codeStyleSettings language="JAVA">
+      <option name="RIGHT_MARGIN" value="80" />
+      <option name="ALIGN_MULTILINE_PARAMETERS" value="false" />
+      <option name="ALIGN_MULTILINE_RESOURCES" value="false" />
+      <option name="ALIGN_MULTILINE_FOR" value="false" />
+      <option name="SPACE_BEFORE_ARRAY_INITIALIZER_LBRACE" value="true" />
+      <option name="CALL_PARAMETERS_WRAP" value="1" />
+      <option name="METHOD_PARAMETERS_WRAP" value="1" />
+      <option name="RESOURCE_LIST_WRAP" value="1" />
+      <option name="EXTENDS_LIST_WRAP" value="1" />
+      <option name="THROWS_LIST_WRAP" value="1" />
+      <option name="EXTENDS_KEYWORD_WRAP" value="1" />
+      <option name="THROWS_KEYWORD_WRAP" value="1" />
+      <option name="METHOD_CALL_CHAIN_WRAP" value="1" />
+      <option name="BINARY_OPERATION_WRAP" value="1" />
+      <option name="TERNARY_OPERATION_WRAP" value="1" />
+      <option name="FOR_STATEMENT_WRAP" value="1" />
+      <option name="ARRAY_INITIALIZER_WRAP" value="1" />
+      <option name="ASSIGNMENT_WRAP" value="1" />
+      <option name="ASSERT_STATEMENT_WRAP" value="1" />
+      <option name="PARAMETER_ANNOTATION_WRAP" value="1" />
+      <option name="VARIABLE_ANNOTATION_WRAP" value="1" />
+      <option name="ENUM_CONSTANTS_WRAP" value="1" />
+      <indentOptions>
+        <option name="USE_TAB_CHARACTER" value="true" />
+        <option name="SMART_TABS" value="true" />
+      </indentOptions>
+    </codeStyleSettings>
+    <codeStyleSettings language="XML">
+      <indentOptions>
+        <option name="CONTINUATION_INDENT_SIZE" value="4" />
+        <option name="USE_TAB_CHARACTER" value="true" />
+        <option name="SMART_TABS" value="true" />
+      </indentOptions>
+      <arrangement>
+        <rules>
+          <section>
+            <rule>
+              <match>
+                <AND>
+                  <NAME>xmlns:android</NAME>
+                  <XML_ATTRIBUTE />
+                  <XML_NAMESPACE>^$</XML_NAMESPACE>
+                </AND>
+              </match>
+            </rule>
+          </section>
+          <section>
+            <rule>
+              <match>
+                <AND>
+                  <NAME>xmlns:.*</NAME>
+                  <XML_ATTRIBUTE />
+                  <XML_NAMESPACE>^$</XML_NAMESPACE>
+                </AND>
+              </match>
+              <order>BY_NAME</order>
+            </rule>
+          </section>
+          <section>
+            <rule>
+              <match>
+                <AND>
+                  <NAME>.*:id</NAME>
+                  <XML_ATTRIBUTE />
+                  <XML_NAMESPACE>http://schemas.android.com/apk/res/android</XML_NAMESPACE>
+                </AND>
+              </match>
+            </rule>
+          </section>
+          <section>
+            <rule>
+              <match>
+                <AND>
+                  <NAME>.*:name</NAME>
+                  <XML_ATTRIBUTE />
+                  <XML_NAMESPACE>http://schemas.android.com/apk/res/android</XML_NAMESPACE>
+                </AND>
+              </match>
+            </rule>
+          </section>
+          <section>
+            <rule>
+              <match>
+                <AND>
+                  <NAME>name</NAME>
+                  <XML_ATTRIBUTE />
+                  <XML_NAMESPACE>^$</XML_NAMESPACE>
+                </AND>
+              </match>
+            </rule>
+          </section>
+          <section>
+            <rule>
+              <match>
+                <AND>
+                  <NAME>style</NAME>
+                  <XML_ATTRIBUTE />
+                  <XML_NAMESPACE>^$</XML_NAMESPACE>
+                </AND>
+              </match>
+            </rule>
+          </section>
+          <section>
+            <rule>
+              <match>
+                <AND>
+                  <NAME>.*</NAME>
+                  <XML_ATTRIBUTE />
+                  <XML_NAMESPACE>^$</XML_NAMESPACE>
+                </AND>
+              </match>
+              <order>BY_NAME</order>
+            </rule>
+          </section>
+          <section>
+            <rule>
+              <match>
+                <AND>
+                  <NAME>.*</NAME>
+                  <XML_ATTRIBUTE />
+                  <XML_NAMESPACE>http://schemas.android.com/apk/res/android</XML_NAMESPACE>
+                </AND>
+              </match>
+              <order>ANDROID_ATTRIBUTE_ORDER</order>
+            </rule>
+          </section>
+          <section>
+            <rule>
+              <match>
+                <AND>
+                  <NAME>.*</NAME>
+                  <XML_ATTRIBUTE />
+                  <XML_NAMESPACE>.*</XML_NAMESPACE>
+                </AND>
+              </match>
+              <order>BY_NAME</order>
+            </rule>
+          </section>
+        </rules>
+      </arrangement>
+    </codeStyleSettings>
+    <codeStyleSettings language="kotlin">
+      <option name="CODE_STYLE_DEFAULTS" value="KOTLIN_OFFICIAL" />
+      <option name="PARAMETER_ANNOTATION_WRAP" value="1" />
+      <option name="VARIABLE_ANNOTATION_WRAP" value="1" />
+      <option name="ENUM_CONSTANTS_WRAP" value="1" />
+    </codeStyleSettings>
+  </code_scheme>
+</component>

.idea/codeStyles/codeStyleConfig.xml

@@ -0,0 +1,5 @@
+<component name="ProjectCodeStyleConfiguration">
+  <state>
+    <option name="USE_PER_PROJECT_SETTINGS" value="true" />
+  </state>
+</component>

.idea/runConfigurations/All_tests.xml

@@ -0,0 +1,20 @@
+<component name="ProjectRunConfigurationManager">
+  <configuration default="false" name="All tests" type="AndroidJUnit" factoryName="Android JUnit">
+    <module name="briar-android" />
+    <option name="PACKAGE_NAME" value="" />
+    <option name="MAIN_CLASS_NAME" value="" />
+    <option name="METHOD_NAME" value="" />
+    <option name="TEST_OBJECT" value="package" />
+    <option name="PARAMETERS" value="" />
+    <option name="WORKING_DIRECTORY" value="$PROJECT_DIR$/briar-android" />
+    <method v="2">
+      <option name="Android.Gradle.BeforeRunTask" enabled="true" />
+      <option name="RunConfigurationTask" enabled="true" run_configuration_name="All tests in bramble-api" run_configuration_type="AndroidJUnit" />
+      <option name="RunConfigurationTask" enabled="true" run_configuration_name="All tests in bramble-core" run_configuration_type="AndroidJUnit" />
+      <option name="RunConfigurationTask" enabled="true" run_configuration_name="All tests in bramble-android" run_configuration_type="AndroidJUnit" />
+      <option name="RunConfigurationTask" enabled="true" run_configuration_name="All tests in bramble-java" run_configuration_type="AndroidJUnit" />
+      <option name="RunConfigurationTask" enabled="true" run_configuration_name="All tests in briar-core" run_configuration_type="AndroidJUnit" />
+      <option name="RunConfigurationTask" enabled="true" run_configuration_name="All tests in briar-headless" run_configuration_type="AndroidJUnit" />
+    </method>
+  </configuration>
+</component>

.idea/runConfigurations/All_tests_in_bramble_android.xml

@@ -0,0 +1,20 @@
+<component name="ProjectRunConfigurationManager">
+  <configuration default="false" name="All tests in bramble-android" type="AndroidJUnit" factoryName="Android JUnit">
+    <module name="bramble-android" />
+    <option name="ALTERNATIVE_JRE_PATH_ENABLED" value="false" />
+    <option name="ALTERNATIVE_JRE_PATH" />
+    <option name="PACKAGE_NAME" value="" />
+    <option name="MAIN_CLASS_NAME" value="" />
+    <option name="METHOD_NAME" value="" />
+    <option name="TEST_OBJECT" value="package" />
+    <option name="VM_PARAMETERS" value="-ea" />
+    <option name="PARAMETERS" value="" />
+    <option name="WORKING_DIRECTORY" value="file://$PROJECT_DIR$/bramble-android" />
+    <option name="PASS_PARENT_ENVS" value="true" />
+    <option name="TEST_SEARCH_SCOPE">
+      <value defaultName="singleModule" />
+    </option>
+    <patterns />
+    <method />
+  </configuration>
+</component>

.idea/runConfigurations/All_tests_in_bramble_api.xml

@@ -0,0 +1,20 @@
+<component name="ProjectRunConfigurationManager">
+  <configuration default="false" name="All tests in bramble-api" type="AndroidJUnit" factoryName="Android JUnit">
+    <module name="bramble-api" />
+    <option name="ALTERNATIVE_JRE_PATH_ENABLED" value="false" />
+    <option name="ALTERNATIVE_JRE_PATH" />
+    <option name="PACKAGE_NAME" value="" />
+    <option name="MAIN_CLASS_NAME" value="" />
+    <option name="METHOD_NAME" value="" />
+    <option name="TEST_OBJECT" value="package" />
+    <option name="VM_PARAMETERS" value="-ea" />
+    <option name="PARAMETERS" value="" />
+    <option name="WORKING_DIRECTORY" value="file://$PROJECT_DIR$/bramble-api" />
+    <option name="PASS_PARENT_ENVS" value="true" />
+    <option name="TEST_SEARCH_SCOPE">
+      <value defaultName="singleModule" />
+    </option>
+    <patterns />
+    <method />
+  </configuration>
+</component>

.idea/runConfigurations/All_tests_in_bramble_core.xml

@@ -0,0 +1,20 @@
+<component name="ProjectRunConfigurationManager">
+  <configuration default="false" name="All tests in bramble-core" type="AndroidJUnit" factoryName="Android JUnit">
+    <module name="bramble-core" />
+    <option name="ALTERNATIVE_JRE_PATH_ENABLED" value="false" />
+    <option name="ALTERNATIVE_JRE_PATH" />
+    <option name="PACKAGE_NAME" value="" />
+    <option name="MAIN_CLASS_NAME" value="" />
+    <option name="METHOD_NAME" value="" />
+    <option name="TEST_OBJECT" value="package" />
+    <option name="VM_PARAMETERS" value="-ea" />
+    <option name="PARAMETERS" value="" />
+    <option name="WORKING_DIRECTORY" value="file://$PROJECT_DIR$/bramble-core" />
+    <option name="PASS_PARENT_ENVS" value="true" />
+    <option name="TEST_SEARCH_SCOPE">
+      <value defaultName="singleModule" />
+    </option>
+    <patterns />
+    <method />
+  </configuration>
+</component>

.idea/runConfigurations/All_tests_in_bramble_java.xml

@@ -0,0 +1,20 @@
+<component name="ProjectRunConfigurationManager">
+  <configuration default="false" name="All tests in bramble-java" type="AndroidJUnit" factoryName="Android JUnit">
+    <module name="bramble-java" />
+    <option name="ALTERNATIVE_JRE_PATH_ENABLED" value="false" />
+    <option name="ALTERNATIVE_JRE_PATH" />
+    <option name="PACKAGE_NAME" value="" />
+    <option name="MAIN_CLASS_NAME" value="" />
+    <option name="METHOD_NAME" value="" />
+    <option name="TEST_OBJECT" value="package" />
+    <option name="VM_PARAMETERS" value="-ea -Djava.library.path=libs" />
+    <option name="PARAMETERS" value="" />
+    <option name="WORKING_DIRECTORY" value="file://$PROJECT_DIR$/bramble-java" />
+    <option name="PASS_PARENT_ENVS" value="true" />
+    <option name="TEST_SEARCH_SCOPE">
+      <value defaultName="singleModule" />
+    </option>
+    <patterns />
+    <method />
+  </configuration>
+</component>

.idea/runConfigurations/All_tests_in_briar_android.xml

@@ -0,0 +1,20 @@
+<component name="ProjectRunConfigurationManager">
+  <configuration default="false" name="All tests in briar-android" type="AndroidJUnit" factoryName="Android JUnit">
+    <module name="briar-android" />
+    <option name="ALTERNATIVE_JRE_PATH_ENABLED" value="false" />
+    <option name="ALTERNATIVE_JRE_PATH" />
+    <option name="PACKAGE_NAME" value="" />
+    <option name="MAIN_CLASS_NAME" value="" />
+    <option name="METHOD_NAME" value="" />
+    <option name="TEST_OBJECT" value="package" />
+    <option name="VM_PARAMETERS" value="-ea" />
+    <option name="PARAMETERS" value="" />
+    <option name="WORKING_DIRECTORY" value="file://$PROJECT_DIR$/briar-android" />
+    <option name="PASS_PARENT_ENVS" value="true" />
+    <option name="TEST_SEARCH_SCOPE">
+      <value defaultName="singleModule" />
+    </option>
+    <patterns />
+    <method />
+  </configuration>
+</component>

.idea/runConfigurations/All_tests_in_briar_core.xml

@@ -0,0 +1,20 @@
+<component name="ProjectRunConfigurationManager">
+  <configuration default="false" name="All tests in briar-core" type="AndroidJUnit" factoryName="Android JUnit">
+    <module name="briar-core" />
+    <option name="ALTERNATIVE_JRE_PATH_ENABLED" value="false" />
+    <option name="ALTERNATIVE_JRE_PATH" />
+    <option name="PACKAGE_NAME" value="" />
+    <option name="MAIN_CLASS_NAME" value="" />
+    <option name="METHOD_NAME" value="" />
+    <option name="TEST_OBJECT" value="package" />
+    <option name="VM_PARAMETERS" value="-ea" />
+    <option name="PARAMETERS" value="" />
+    <option name="WORKING_DIRECTORY" value="file://$PROJECT_DIR$/briar-core" />
+    <option name="PASS_PARENT_ENVS" value="true" />
+    <option name="TEST_SEARCH_SCOPE">
+      <value defaultName="singleModule" />
+    </option>
+    <patterns />
+    <method />
+  </configuration>
+</component>

.idea/runConfigurations/All_tests_in_briar_headless.xml

@@ -0,0 +1,15 @@
+<component name="ProjectRunConfigurationManager">
+  <configuration default="false" name="All tests in briar-headless" type="AndroidJUnit" factoryName="Android JUnit">
+    <module name="briar-headless" />
+    <option name="PACKAGE_NAME" value="org.briarproject.briar.headless" />
+    <option name="MAIN_CLASS_NAME" value="" />
+    <option name="METHOD_NAME" value="" />
+    <option name="TEST_OBJECT" value="package" />
+    <option name="VM_PARAMETERS" />
+    <option name="PARAMETERS" value="" />
+    <option name="WORKING_DIRECTORY" value="$PROJECT_DIR$/briar-headless" />
+    <method v="2">
+      <option name="Android.Gradle.BeforeRunTask" enabled="true" />
+    </method>
+  </configuration>
+</component>

.idea/runConfigurations/H2_Performance_Test.xml

@@ -0,0 +1,20 @@
+<component name="ProjectRunConfigurationManager">
+  <configuration default="false" name="H2 Performance Test" type="AndroidJUnit" factoryName="Android JUnit">
+    <module name="bramble-core" />
+    <option name="ALTERNATIVE_JRE_PATH_ENABLED" value="false" />
+    <option name="ALTERNATIVE_JRE_PATH" />
+    <option name="PACKAGE_NAME" value="org.briarproject.bramble.db" />
+    <option name="MAIN_CLASS_NAME" value="org.briarproject.bramble.db.H2DatabasePerformanceTest" />
+    <option name="METHOD_NAME" value="" />
+    <option name="TEST_OBJECT" value="class" />
+    <option name="VM_PARAMETERS" value="-ea" />
+    <option name="PARAMETERS" value="" />
+    <option name="WORKING_DIRECTORY" value="" />
+    <option name="PASS_PARENT_ENVS" value="true" />
+    <option name="TEST_SEARCH_SCOPE">
+      <value defaultName="singleModule" />
+    </option>
+    <patterns />
+    <method />
+  </configuration>
+</component>

.idea/runConfigurations/HyperSQL_Performance_Test.xml

@@ -0,0 +1,20 @@
+<component name="ProjectRunConfigurationManager">
+  <configuration default="false" name="HyperSQL Performance Test" type="AndroidJUnit" factoryName="Android JUnit">
+    <module name="bramble-core" />
+    <option name="ALTERNATIVE_JRE_PATH_ENABLED" value="false" />
+    <option name="ALTERNATIVE_JRE_PATH" />
+    <option name="PACKAGE_NAME" value="org.briarproject.bramble.db" />
+    <option name="MAIN_CLASS_NAME" value="org.briarproject.bramble.db.HyperSqlDatabasePerformanceTest" />
+    <option name="METHOD_NAME" value="" />
+    <option name="TEST_OBJECT" value="class" />
+    <option name="VM_PARAMETERS" value="-ea" />
+    <option name="PARAMETERS" value="" />
+    <option name="WORKING_DIRECTORY" value="" />
+    <option name="PASS_PARENT_ENVS" value="true" />
+    <option name="TEST_SEARCH_SCOPE">
+      <value defaultName="singleModule" />
+    </option>
+    <patterns />
+    <method />
+  </configuration>
+</component>

.idea/runConfigurations/briar_headless.xml

@@ -0,0 +1,17 @@
+<component name="ProjectRunConfigurationManager">
+  <configuration default="false" name="briar-headless" type="JetRunConfigurationType" factoryName="Kotlin" singleton="true">
+    <extension name="coverage" enabled="false" merge="false" sample_coverage="true" runner="idea" />
+    <option name="VM_PARAMETERS" value="" />
+    <option name="PROGRAM_PARAMETERS" value="-v" />
+    <option name="ALTERNATIVE_JRE_PATH_ENABLED" value="false" />
+    <option name="ALTERNATIVE_JRE_PATH" />
+    <option name="PASS_PARENT_ENVS" value="true" />
+    <option name="MAIN_CLASS_NAME" value="org.briarproject.briar.headless.MainKt" />
+    <option name="WORKING_DIRECTORY" value="" />
+    <module name="briar-headless" />
+    <envs />
+    <method>
+      <option name="Gradle.BeforeRunTask" enabled="true" tasks="jar" externalProjectPath="$PROJECT_DIR$/briar-headless" vmOptions="" scriptParameters="" />
+    </method>
+  </configuration>
+</component>

LICENSE.txt

@@ -13,23 +13,6 @@
     You should have received a copy of the GNU General Public License
     along with this program.  If not, see <http://www.gnu.org/licenses/>.
 
--------------------------------------------------------------------------
-
-    All files under the directories briar-android/src, briar-api/src,
-    briar-core/src, briar-desktop/src and briar-test/src are licensed
-    under the Apache License, version 2.0 (the "License"); you may not
-    use these files except in compliance with the License.
-
-    You may obtain a copy of the License at
-
-    http://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.
-
 -------------------------------------------------------------------------
 
                     GNU GENERAL PUBLIC LICENSE

bramble-android/.gitignore

@@ -0,0 +1,5 @@
+bin
+gen
+build
+.settings
+src/main/res/raw/*.zip

bramble-android/build.gradle

@@ -0,0 +1,80 @@
+import com.android.build.gradle.tasks.MergeResources
+
+apply plugin: 'com.android.library'
+apply plugin: 'witness'
+apply from: 'witness.gradle'
+
+android {
+	compileSdkVersion 29
+	buildToolsVersion '29.0.2'
+
+	defaultConfig {
+		minSdkVersion 16
+		targetSdkVersion 28
+		versionCode 10205
+		versionName "1.2.5"
+		consumerProguardFiles 'proguard-rules.txt'
+
+		testInstrumentationRunner "androidx.test.runner.AndroidJUnitRunner"
+	}
+
+	compileOptions {
+		sourceCompatibility JavaVersion.VERSION_1_8
+		targetCompatibility JavaVersion.VERSION_1_8
+	}
+
+	lintOptions {
+		// FIXME
+		warning "LintError"
+		warning "InvalidPackage"
+		warning "MissingPermission"
+		warning "InlinedApi", "ObsoleteSdkInt", "Override", "NewApi", "UnusedAttribute"
+	}
+}
+
+configurations {
+	tor
+}
+
+dependencies {
+	implementation project(path: ':bramble-core', configuration: 'default')
+	tor 'org.briarproject:tor-android:0.3.5.9@zip'
+	tor 'org.briarproject:obfs4proxy-android:0.0.11-2@zip'
+
+	annotationProcessor 'com.google.dagger:dagger-compiler:2.24'
+
+	compileOnly 'javax.annotation:jsr250-api:1.0'
+
+	testImplementation project(path: ':bramble-api', configuration: 'testOutput')
+	testImplementation 'junit:junit:4.12'
+	testImplementation "org.jmock:jmock:2.8.2"
+	testImplementation "org.jmock:jmock-junit4:2.8.2"
+	testImplementation "org.jmock:jmock-legacy:2.8.2"
+}
+
+def torBinariesDir = 'src/main/res/raw'
+
+task cleanTorBinaries {
+	doLast {
+		delete fileTree(torBinariesDir) { include '*.zip' }
+	}
+}
+
+clean.dependsOn cleanTorBinaries
+
+task unpackTorBinaries {
+	doLast {
+		copy {
+			from configurations.tor.collect { zipTree(it) }
+			into torBinariesDir
+			// TODO: Remove after next Tor upgrade, which won't include non-PIE binaries
+			include 'geoip.zip', '*_pie.zip'
+		}
+	}
+	dependsOn cleanTorBinaries
+}
+
+tasks.withType(MergeResources) {
+	inputs.dir torBinariesDir
+	dependsOn unpackTorBinaries
+}

bramble-android/proguard-rules.txt

@@ -0,0 +1,19 @@
+-keep,includedescriptorclasses class org.briarproject.** { *; }
+
+-keep class org.h2.** { *; }
+-dontwarn org.h2.**
+-dontnote org.h2.**
+
+-keep class dagger.** { *; }
+-dontwarn dagger.**
+-dontnote dagger.**
+
+-keep class net.i2p.crypto.eddsa.** { *; }
+
+-keep class org.whispersystems.curve25519.** { *; }
+
+-dontwarn sun.misc.Unsafe
+-dontnote com.google.common.**
+
+# UPnP library isn't used
+-dontwarn org.bitlet.weupnp.**

bramble-android/src/main/AndroidManifest.xml

@@ -0,0 +1,21 @@
+<manifest
+	package="org.briarproject.bramble"
+	xmlns:android="http://schemas.android.com/apk/res/android">
+
+	<uses-feature android:name="android.hardware.bluetooth" android:required="false"/>
+
+	<uses-permission android:name="android.permission.ACCESS_NETWORK_STATE"/>
+	<uses-permission android:name="android.permission.ACCESS_WIFI_STATE"/>
+	<uses-permission android:name="android.permission.BLUETOOTH"/>
+	<uses-permission android:name="android.permission.BLUETOOTH_ADMIN"/>
+	<uses-permission android:name="android.permission.INTERNET"/>
+	<uses-permission android:name="android.permission.WAKE_LOCK"/>
+
+	<application
+		android:allowBackup="false"
+		android:label="@string/app_name"
+		android:supportsRtl="true">
+
+	</application>
+
+</manifest>

bramble-android/src/main/java/org/briarproject/bramble/BrambleAndroidEagerSingletons.java

@@ -0,0 +1,24 @@
+package org.briarproject.bramble;
+
+import org.briarproject.bramble.battery.AndroidBatteryModule;
+import org.briarproject.bramble.network.AndroidNetworkModule;
+import org.briarproject.bramble.reporting.ReportingModule;
+
+public interface BrambleAndroidEagerSingletons {
+
+	void inject(AndroidBatteryModule.EagerSingletons init);
+
+	void inject(AndroidNetworkModule.EagerSingletons init);
+
+	void inject(ReportingModule.EagerSingletons init);
+
+	class Helper {
+
+		public static void injectEagerSingletons(
+				BrambleAndroidEagerSingletons c) {
+			c.inject(new AndroidBatteryModule.EagerSingletons());
+			c.inject(new AndroidNetworkModule.EagerSingletons());
+			c.inject(new ReportingModule.EagerSingletons());
+		}
+	}
+}

bramble-android/src/main/java/org/briarproject/bramble/BrambleAndroidModule.java

@@ -0,0 +1,21 @@
+package org.briarproject.bramble;
+
+import org.briarproject.bramble.battery.AndroidBatteryModule;
+import org.briarproject.bramble.network.AndroidNetworkModule;
+import org.briarproject.bramble.plugin.tor.CircumventionModule;
+import org.briarproject.bramble.reporting.ReportingModule;
+import org.briarproject.bramble.socks.SocksModule;
+import org.briarproject.bramble.system.AndroidSystemModule;
+
+import dagger.Module;
+
+@Module(includes = {
+		AndroidBatteryModule.class,
+		AndroidNetworkModule.class,
+		AndroidSystemModule.class,
+		CircumventionModule.class,
+		ReportingModule.class,
+		SocksModule.class
+})
+public class BrambleAndroidModule {
+}

bramble-android/src/main/java/org/briarproject/bramble/account/AndroidAccountManager.java

@@ -0,0 +1,127 @@
+package org.briarproject.bramble.account;
+
+import android.app.Application;
+import android.content.Context;
+import android.content.SharedPreferences;
+import android.preference.PreferenceManager;
+
+import org.briarproject.bramble.api.account.AccountManager;
+import org.briarproject.bramble.api.crypto.CryptoComponent;
+import org.briarproject.bramble.api.db.DatabaseConfig;
+import org.briarproject.bramble.api.identity.IdentityManager;
+
+import java.io.File;
+import java.util.HashSet;
+import java.util.Set;
+import java.util.logging.Logger;
+
+import javax.annotation.Nullable;
+import javax.annotation.concurrent.GuardedBy;
+import javax.inject.Inject;
+
+import static android.os.Build.VERSION.SDK_INT;
+import static java.util.logging.Level.INFO;
+import static org.briarproject.bramble.util.IoUtils.deleteFileOrDir;
+import static org.briarproject.bramble.util.LogUtils.logFileOrDir;
+
+class AndroidAccountManager extends AccountManagerImpl
+		implements AccountManager {
+
+	private static final Logger LOG =
+			Logger.getLogger(AndroidAccountManager.class.getName());
+
+	protected final Context appContext;
+	private final SharedPreferences prefs;
+
+	@Inject
+	AndroidAccountManager(DatabaseConfig databaseConfig,
+			CryptoComponent crypto, IdentityManager identityManager,
+			SharedPreferences prefs, Application app) {
+		super(databaseConfig, crypto, identityManager);
+		this.prefs = prefs;
+		appContext = app.getApplicationContext();
+	}
+
+	@Override
+	public boolean accountExists() {
+		boolean exists = super.accountExists();
+		if (!exists && LOG.isLoggable(INFO)) {
+			LOG.info("Account does not exist. Contents of account directory:");
+			logFileOrDir(LOG, INFO, getDataDir());
+		}
+		return exists;
+	}
+
+	@Override
+	public void deleteAccount() {
+		synchronized (stateChangeLock) {
+			if (LOG.isLoggable(INFO)) {
+				LOG.info("Contents of account directory before deleting:");
+				logFileOrDir(LOG, INFO, getDataDir());
+			}
+			super.deleteAccount();
+			SharedPreferences defaultPrefs = getDefaultSharedPreferences();
+			deleteAppData(prefs, defaultPrefs);
+			if (LOG.isLoggable(INFO)) {
+				LOG.info("Contents of account directory after deleting:");
+				logFileOrDir(LOG, INFO, getDataDir());
+			}
+		}
+	}
+
+	// Package access for testing
+	SharedPreferences getDefaultSharedPreferences() {
+		return PreferenceManager.getDefaultSharedPreferences(appContext);
+	}
+
+	@GuardedBy("stateChangeLock")
+	private void deleteAppData(SharedPreferences... clear) {
+		// Clear and commit shared preferences
+		for (SharedPreferences prefs : clear) {
+			if (!prefs.edit().clear().commit())
+				LOG.warning("Could not clear shared preferences");
+		}
+		// Delete files, except lib and shared_prefs directories
+		Set<File> files = new HashSet<>();
+		File dataDir = getDataDir();
+		@Nullable
+		File[] fileArray = dataDir.listFiles();
+		if (fileArray == null) {
+			LOG.warning("Could not list files in app data dir");
+		} else {
+			for (File file : fileArray) {
+				String name = file.getName();
+				if (!name.equals("lib") && !name.equals("shared_prefs")) {
+					files.add(file);
+				}
+			}
+		}
+		files.add(appContext.getFilesDir());
+		files.add(appContext.getCacheDir());
+		addIfNotNull(files, appContext.getExternalCacheDir());
+		if (SDK_INT >= 19) {
+			for (File file : appContext.getExternalCacheDirs()) {
+				addIfNotNull(files, file);
+			}
+		}
+		if (SDK_INT >= 21) {
+			for (File file : appContext.getExternalMediaDirs()) {
+				addIfNotNull(files, file);
+			}
+		}
+		for (File file : files) {
+			deleteFileOrDir(file);
+		}
+		// Recreate the cache dir as some OpenGL drivers expect it to exist
+		if (!new File(dataDir, "cache").mkdirs())
+			LOG.warning("Could not recreate cache dir");
+	}
+
+	private File getDataDir() {
+		return new File(appContext.getApplicationInfo().dataDir);
+	}
+
+	private void addIfNotNull(Set<File> files, @Nullable File file) {
+		if (file != null) files.add(file);
+	}
+}

bramble-android/src/main/java/org/briarproject/bramble/api/system/AndroidExecutor.java

@@ -0,0 +1,33 @@
+package org.briarproject.bramble.api.system;
+
+import java.util.concurrent.Callable;
+import java.util.concurrent.Future;
+
+/**
+ * Enables background threads to make Android API calls that must be made from
+ * a thread with a message queue.
+ */
+public interface AndroidExecutor {
+
+	/**
+	 * Runs the given task on a background thread with a message queue and
+	 * returns a Future for getting the result.
+	 */
+	<V> Future<V> runOnBackgroundThread(Callable<V> c);
+
+	/**
+	 * Runs the given task on a background thread with a message queue.
+	 */
+	void runOnBackgroundThread(Runnable r);
+
+	/**
+	 * Runs the given task on the main UI thread and returns a Future for
+	 * getting the result.
+	 */
+	<V> Future<V> runOnUiThread(Callable<V> c);
+
+	/**
+	 * Runs the given task on the main UI thread.
+	 */
+	void runOnUiThread(Runnable r);
+}

bramble-android/src/main/java/org/briarproject/bramble/battery/AndroidBatteryManager.java

@@ -0,0 +1,81 @@
+package org.briarproject.bramble.battery;
+
+import android.app.Application;
+import android.content.BroadcastReceiver;
+import android.content.Context;
+import android.content.Intent;
+import android.content.IntentFilter;
+
+import org.briarproject.bramble.api.battery.BatteryManager;
+import org.briarproject.bramble.api.battery.event.BatteryEvent;
+import org.briarproject.bramble.api.event.EventBus;
+import org.briarproject.bramble.api.lifecycle.Service;
+
+import java.util.concurrent.atomic.AtomicBoolean;
+import java.util.logging.Logger;
+
+import javax.inject.Inject;
+
+import static android.content.Intent.ACTION_BATTERY_CHANGED;
+import static android.content.Intent.ACTION_POWER_CONNECTED;
+import static android.content.Intent.ACTION_POWER_DISCONNECTED;
+import static android.os.BatteryManager.EXTRA_PLUGGED;
+import static java.util.logging.Level.INFO;
+import static java.util.logging.Logger.getLogger;
+
+class AndroidBatteryManager implements BatteryManager, Service {
+
+	private static final Logger LOG =
+			getLogger(AndroidBatteryManager.class.getName());
+
+	private final Context appContext;
+	private final EventBus eventBus;
+	private final AtomicBoolean used = new AtomicBoolean(false);
+
+	private volatile BroadcastReceiver batteryReceiver = null;
+
+	@Inject
+	AndroidBatteryManager(Application app, EventBus eventBus) {
+		this.appContext = app.getApplicationContext();
+		this.eventBus = eventBus;
+	}
+
+	@Override
+	public boolean isCharging() {
+		// Get the sticky intent for ACTION_BATTERY_CHANGED
+		IntentFilter filter = new IntentFilter(ACTION_BATTERY_CHANGED);
+		Intent i = appContext.registerReceiver(null, filter);
+		if (i == null) return false;
+		int status = i.getIntExtra(EXTRA_PLUGGED, 0);
+		return status != 0;
+	}
+
+	@Override
+	public void startService() {
+		if (used.getAndSet(true)) throw new IllegalStateException();
+		batteryReceiver = new BatteryReceiver();
+		IntentFilter filter = new IntentFilter();
+		filter.addAction(ACTION_POWER_CONNECTED);
+		filter.addAction(ACTION_POWER_DISCONNECTED);
+		appContext.registerReceiver(batteryReceiver, filter);
+	}
+
+	@Override
+	public void stopService() {
+		if (batteryReceiver != null)
+			appContext.unregisterReceiver(batteryReceiver);
+	}
+
+	private class BatteryReceiver extends BroadcastReceiver {
+
+		@Override
+		public void onReceive(Context ctx, Intent i) {
+			String action = i.getAction();
+			if (LOG.isLoggable(INFO)) LOG.info("Received broadcast " + action);
+			if (ACTION_POWER_CONNECTED.equals(action))
+				eventBus.broadcast(new BatteryEvent(true));
+			else if (ACTION_POWER_DISCONNECTED.equals(action))
+				eventBus.broadcast(new BatteryEvent(false));
+		}
+	}
+}

bramble-android/src/main/java/org/briarproject/bramble/battery/AndroidBatteryModule.java

@@ -0,0 +1,27 @@
+package org.briarproject.bramble.battery;
+
+import org.briarproject.bramble.api.battery.BatteryManager;
+import org.briarproject.bramble.api.lifecycle.LifecycleManager;
+
+import javax.inject.Inject;
+import javax.inject.Singleton;
+
+import dagger.Module;
+import dagger.Provides;
+
+@Module
+public class AndroidBatteryModule {
+
+	public static class EagerSingletons {
+		@Inject
+		BatteryManager batteryManager;
+	}
+
+	@Provides
+	@Singleton
+	BatteryManager provideBatteryManager(LifecycleManager lifecycleManager,
+			AndroidBatteryManager batteryManager) {
+		lifecycleManager.registerService(batteryManager);
+		return batteryManager;
+	}
+}

bramble-android/src/main/java/org/briarproject/bramble/network/AndroidNetworkManager.java

@@ -0,0 +1,142 @@
+package org.briarproject.bramble.network;
+
+import android.app.Application;
+import android.content.BroadcastReceiver;
+import android.content.Context;
+import android.content.Intent;
+import android.content.IntentFilter;
+import android.net.ConnectivityManager;
+import android.net.NetworkInfo;
+
+import org.briarproject.bramble.api.event.EventBus;
+import org.briarproject.bramble.api.lifecycle.Service;
+import org.briarproject.bramble.api.network.NetworkManager;
+import org.briarproject.bramble.api.network.NetworkStatus;
+import org.briarproject.bramble.api.network.event.NetworkStatusEvent;
+import org.briarproject.bramble.api.nullsafety.MethodsNotNullByDefault;
+import org.briarproject.bramble.api.nullsafety.ParametersNotNullByDefault;
+import org.briarproject.bramble.api.system.Scheduler;
+
+import java.util.concurrent.Future;
+import java.util.concurrent.ScheduledExecutorService;
+import java.util.concurrent.TimeUnit;
+import java.util.concurrent.atomic.AtomicBoolean;
+import java.util.concurrent.atomic.AtomicReference;
+import java.util.logging.Logger;
+
+import javax.annotation.Nullable;
+import javax.inject.Inject;
+
+import static android.content.Context.CONNECTIVITY_SERVICE;
+import static android.content.Intent.ACTION_SCREEN_OFF;
+import static android.content.Intent.ACTION_SCREEN_ON;
+import static android.net.ConnectivityManager.CONNECTIVITY_ACTION;
+import static android.net.ConnectivityManager.TYPE_WIFI;
+import static android.os.Build.VERSION.SDK_INT;
+import static android.os.PowerManager.ACTION_DEVICE_IDLE_MODE_CHANGED;
+import static java.util.concurrent.TimeUnit.MINUTES;
+import static java.util.concurrent.TimeUnit.SECONDS;
+import static java.util.logging.Level.INFO;
+
+@MethodsNotNullByDefault
+@ParametersNotNullByDefault
+class AndroidNetworkManager implements NetworkManager, Service {
+
+	private static final Logger LOG =
+			Logger.getLogger(AndroidNetworkManager.class.getName());
+
+	// See android.net.wifi.WifiManager
+	private static final String WIFI_AP_STATE_CHANGED_ACTION =
+			"android.net.wifi.WIFI_AP_STATE_CHANGED";
+
+	private final ScheduledExecutorService scheduler;
+	private final EventBus eventBus;
+	private final Context appContext;
+	private final AtomicReference<Future<?>> connectivityCheck =
+			new AtomicReference<>();
+	private final AtomicBoolean used = new AtomicBoolean(false);
+
+	private volatile BroadcastReceiver networkStateReceiver = null;
+
+	@Inject
+	AndroidNetworkManager(@Scheduler ScheduledExecutorService scheduler,
+			EventBus eventBus, Application app) {
+		this.scheduler = scheduler;
+		this.eventBus = eventBus;
+		this.appContext = app.getApplicationContext();
+	}
+
+	@Override
+	public void startService() {
+		if (used.getAndSet(true)) throw new IllegalStateException();
+		// Register to receive network status events
+		networkStateReceiver = new NetworkStateReceiver();
+		IntentFilter filter = new IntentFilter();
+		filter.addAction(CONNECTIVITY_ACTION);
+		filter.addAction(ACTION_SCREEN_ON);
+		filter.addAction(ACTION_SCREEN_OFF);
+		filter.addAction(WIFI_AP_STATE_CHANGED_ACTION);
+		if (SDK_INT >= 23) filter.addAction(ACTION_DEVICE_IDLE_MODE_CHANGED);
+		appContext.registerReceiver(networkStateReceiver, filter);
+
+	}
+
+	@Override
+	public void stopService() {
+		if (networkStateReceiver != null)
+			appContext.unregisterReceiver(networkStateReceiver);
+	}
+
+	@Override
+	public NetworkStatus getNetworkStatus() {
+		ConnectivityManager cm = (ConnectivityManager)
+				appContext.getSystemService(CONNECTIVITY_SERVICE);
+		if (cm == null) throw new AssertionError();
+		NetworkInfo net = cm.getActiveNetworkInfo();
+		boolean connected = net != null && net.isConnected();
+		boolean wifi = connected && net.getType() == TYPE_WIFI;
+		return new NetworkStatus(connected, wifi);
+	}
+
+	private void updateConnectionStatus() {
+		eventBus.broadcast(new NetworkStatusEvent(getNetworkStatus()));
+	}
+
+	private void scheduleConnectionStatusUpdate(int delay, TimeUnit unit) {
+		Future<?> newConnectivityCheck =
+				scheduler.schedule(this::updateConnectionStatus, delay, unit);
+		Future<?> oldConnectivityCheck =
+				connectivityCheck.getAndSet(newConnectivityCheck);
+		if (oldConnectivityCheck != null) oldConnectivityCheck.cancel(false);
+	}
+
+	private class NetworkStateReceiver extends BroadcastReceiver {
+
+		@Override
+		public void onReceive(Context ctx, Intent i) {
+			String action = i.getAction();
+			if (LOG.isLoggable(INFO)) LOG.info("Received broadcast " + action);
+			updateConnectionStatus();
+			if (isSleepOrDozeEvent(action)) {
+				// Allow time for the network to be enabled or disabled
+				scheduleConnectionStatusUpdate(1, MINUTES);
+			} else if (isApEvent(action)) {
+				// The state change may be broadcast before the AP address is
+				// visible, so delay handling the event
+				scheduleConnectionStatusUpdate(5, SECONDS);
+			}
+		}
+
+		private boolean isSleepOrDozeEvent(@Nullable String action) {
+			boolean isSleep = ACTION_SCREEN_ON.equals(action) ||
+					ACTION_SCREEN_OFF.equals(action);
+			boolean isDoze = SDK_INT >= 23 &&
+					ACTION_DEVICE_IDLE_MODE_CHANGED.equals(action);
+			return isSleep || isDoze;
+		}
+
+		private boolean isApEvent(@Nullable String action) {
+			return WIFI_AP_STATE_CHANGED_ACTION.equals(action);
+		}
+	}
+}

bramble-android/src/main/java/org/briarproject/bramble/network/AndroidNetworkModule.java

@@ -0,0 +1,27 @@
+package org.briarproject.bramble.network;
+
+import org.briarproject.bramble.api.lifecycle.LifecycleManager;
+import org.briarproject.bramble.api.network.NetworkManager;
+
+import javax.inject.Inject;
+import javax.inject.Singleton;
+
+import dagger.Module;
+import dagger.Provides;
+
+@Module
+public class AndroidNetworkModule {
+
+	public static class EagerSingletons {
+		@Inject
+		NetworkManager networkManager;
+	}
+
+	@Provides
+	@Singleton
+	NetworkManager provideNetworkManager(LifecycleManager lifecycleManager,
+			AndroidNetworkManager networkManager) {
+		lifecycleManager.registerService(networkManager);
+		return networkManager;
+	}
+}

bramble-android/src/main/java/org/briarproject/bramble/plugin/bluetooth/AndroidBluetoothPlugin.java

@@ -0,0 +1,298 @@
+package org.briarproject.bramble.plugin.bluetooth;
+
+import android.bluetooth.BluetoothAdapter;
+import android.bluetooth.BluetoothDevice;
+import android.bluetooth.BluetoothServerSocket;
+import android.bluetooth.BluetoothSocket;
+import android.content.BroadcastReceiver;
+import android.content.Context;
+import android.content.Intent;
+import android.content.IntentFilter;
+
+import org.briarproject.bramble.api.nullsafety.MethodsNotNullByDefault;
+import org.briarproject.bramble.api.nullsafety.ParametersNotNullByDefault;
+import org.briarproject.bramble.api.plugin.Backoff;
+import org.briarproject.bramble.api.plugin.PluginCallback;
+import org.briarproject.bramble.api.plugin.PluginException;
+import org.briarproject.bramble.api.plugin.duplex.DuplexTransportConnection;
+import org.briarproject.bramble.api.system.AndroidExecutor;
+import org.briarproject.bramble.api.system.Clock;
+import org.briarproject.bramble.util.AndroidUtils;
+import org.briarproject.bramble.util.IoUtils;
+
+import java.io.IOException;
+import java.security.SecureRandom;
+import java.util.ArrayList;
+import java.util.Collection;
+import java.util.Collections;
+import java.util.List;
+import java.util.UUID;
+import java.util.concurrent.BlockingQueue;
+import java.util.concurrent.ExecutionException;
+import java.util.concurrent.Executor;
+import java.util.concurrent.LinkedBlockingQueue;
+import java.util.logging.Logger;
+
+import javax.annotation.Nullable;
+
+import static android.bluetooth.BluetoothAdapter.ACTION_DISCOVERY_FINISHED;
+import static android.bluetooth.BluetoothAdapter.ACTION_DISCOVERY_STARTED;
+import static android.bluetooth.BluetoothAdapter.ACTION_SCAN_MODE_CHANGED;
+import static android.bluetooth.BluetoothAdapter.ACTION_STATE_CHANGED;
+import static android.bluetooth.BluetoothAdapter.EXTRA_SCAN_MODE;
+import static android.bluetooth.BluetoothAdapter.EXTRA_STATE;
+import static android.bluetooth.BluetoothAdapter.SCAN_MODE_CONNECTABLE;
+import static android.bluetooth.BluetoothAdapter.SCAN_MODE_CONNECTABLE_DISCOVERABLE;
+import static android.bluetooth.BluetoothAdapter.SCAN_MODE_NONE;
+import static android.bluetooth.BluetoothAdapter.STATE_OFF;
+import static android.bluetooth.BluetoothAdapter.STATE_ON;
+import static android.bluetooth.BluetoothDevice.ACTION_FOUND;
+import static android.bluetooth.BluetoothDevice.EXTRA_DEVICE;
+import static java.util.concurrent.TimeUnit.MILLISECONDS;
+import static java.util.logging.Level.INFO;
+import static java.util.logging.Level.WARNING;
+import static java.util.logging.Logger.getLogger;
+import static org.briarproject.bramble.util.PrivacyUtils.scrubMacAddress;
+
+@MethodsNotNullByDefault
+@ParametersNotNullByDefault
+class AndroidBluetoothPlugin extends BluetoothPlugin<BluetoothServerSocket> {
+
+	private static final Logger LOG =
+			getLogger(AndroidBluetoothPlugin.class.getName());
+
+	private static final int MAX_DISCOVERY_MS = 10_000;
+
+	private final AndroidExecutor androidExecutor;
+	private final Context appContext;
+	private final Clock clock;
+
+	private volatile boolean wasEnabledByUs = false;
+	private volatile BluetoothStateReceiver receiver = null;
+
+	// Non-null if the plugin started successfully
+	private volatile BluetoothAdapter adapter = null;
+
+	AndroidBluetoothPlugin(BluetoothConnectionLimiter connectionLimiter,
+			Executor ioExecutor, AndroidExecutor androidExecutor,
+			Context appContext, SecureRandom secureRandom, Clock clock,
+			Backoff backoff, PluginCallback callback, int maxLatency) {
+		super(connectionLimiter, ioExecutor, secureRandom, backoff, callback,
+				maxLatency);
+		this.androidExecutor = androidExecutor;
+		this.appContext = appContext;
+		this.clock = clock;
+	}
+
+	@Override
+	public void start() throws PluginException {
+		super.start();
+		// Listen for changes to the Bluetooth state
+		IntentFilter filter = new IntentFilter();
+		filter.addAction(ACTION_STATE_CHANGED);
+		filter.addAction(ACTION_SCAN_MODE_CHANGED);
+		receiver = new BluetoothStateReceiver();
+		appContext.registerReceiver(receiver, filter);
+	}
+
+	@Override
+	public void stop() {
+		super.stop();
+		if (receiver != null) appContext.unregisterReceiver(receiver);
+	}
+
+	@Override
+	void initialiseAdapter() throws IOException {
+		// BluetoothAdapter.getDefaultAdapter() must be called on a thread
+		// with a message queue, so submit it to the AndroidExecutor
+		try {
+			adapter = androidExecutor.runOnBackgroundThread(
+					BluetoothAdapter::getDefaultAdapter).get();
+		} catch (InterruptedException | ExecutionException e) {
+			throw new IOException(e);
+		}
+		if (adapter == null)
+			throw new IOException("Bluetooth is not supported");
+	}
+
+	@Override
+	boolean isAdapterEnabled() {
+		return adapter != null && adapter.isEnabled();
+	}
+
+	@Override
+	void enableAdapter() {
+		if (adapter != null && !adapter.isEnabled()) {
+			if (adapter.enable()) {
+				LOG.info("Enabling Bluetooth");
+				wasEnabledByUs = true;
+			} else {
+				LOG.info("Could not enable Bluetooth");
+			}
+		}
+	}
+
+	@Override
+	void disableAdapterIfEnabledByUs() {
+		if (isAdapterEnabled() && wasEnabledByUs) {
+			if (adapter.disable()) LOG.info("Disabling Bluetooth");
+			else LOG.info("Could not disable Bluetooth");
+			wasEnabledByUs = false;
+		}
+	}
+
+	@Override
+	void setEnabledByUs() {
+		wasEnabledByUs = true;
+	}
+
+	@Override
+	@Nullable
+	String getBluetoothAddress() {
+		String address = AndroidUtils.getBluetoothAddress(appContext, adapter);
+		return address.isEmpty() ? null : address;
+	}
+
+	@Override
+	BluetoothServerSocket openServerSocket(String uuid) throws IOException {
+		return adapter.listenUsingInsecureRfcommWithServiceRecord(
+				"RFCOMM", UUID.fromString(uuid));
+	}
+
+	@Override
+	void tryToClose(@Nullable BluetoothServerSocket ss) {
+		IoUtils.tryToClose(ss, LOG, WARNING);
+	}
+
+	@Override
+	DuplexTransportConnection acceptConnection(BluetoothServerSocket ss)
+			throws IOException {
+		return wrapSocket(ss.accept());
+	}
+
+	private DuplexTransportConnection wrapSocket(BluetoothSocket s) {
+		return new AndroidBluetoothTransportConnection(this,
+				connectionLimiter, s);
+	}
+
+	@Override
+	boolean isValidAddress(String address) {
+		return BluetoothAdapter.checkBluetoothAddress(address);
+	}
+
+	@Override
+	DuplexTransportConnection connectTo(String address, String uuid)
+			throws IOException {
+		BluetoothDevice d = adapter.getRemoteDevice(address);
+		UUID u = UUID.fromString(uuid);
+		BluetoothSocket s = null;
+		try {
+			s = d.createInsecureRfcommSocketToServiceRecord(u);
+			s.connect();
+			return wrapSocket(s);
+		} catch (IOException e) {
+			IoUtils.tryToClose(s, LOG, WARNING);
+			throw e;
+		}
+	}
+
+	@Override
+	@Nullable
+	DuplexTransportConnection discoverAndConnect(String uuid) {
+		if (adapter == null) return null;
+		for (String address : discoverDevices()) {
+			try {
+				if (LOG.isLoggable(INFO))
+					LOG.info("Connecting to " + scrubMacAddress(address));
+				return connectTo(address, uuid);
+			} catch (IOException e) {
+				if (LOG.isLoggable(INFO)) {
+					LOG.info("Could not connect to "
+							+ scrubMacAddress(address));
+				}
+			}
+		}
+		LOG.info("Could not connect to any devices");
+		return null;
+	}
+
+	private Collection<String> discoverDevices() {
+		List<String> addresses = new ArrayList<>();
+		BlockingQueue<Intent> intents = new LinkedBlockingQueue<>();
+		DiscoveryReceiver receiver = new DiscoveryReceiver(intents);
+		IntentFilter filter = new IntentFilter();
+		filter.addAction(ACTION_DISCOVERY_STARTED);
+		filter.addAction(ACTION_DISCOVERY_FINISHED);
+		filter.addAction(ACTION_FOUND);
+		appContext.registerReceiver(receiver, filter);
+		try {
+			if (adapter.startDiscovery()) {
+				long now = clock.currentTimeMillis();
+				long end = now + MAX_DISCOVERY_MS;
+				while (now < end) {
+					Intent i = intents.poll(end - now, MILLISECONDS);
+					if (i == null) break;
+					String action = i.getAction();
+					if (ACTION_DISCOVERY_STARTED.equals(action)) {
+						LOG.info("Discovery started");
+					} else if (ACTION_DISCOVERY_FINISHED.equals(action)) {
+						LOG.info("Discovery finished");
+						break;
+					} else if (ACTION_FOUND.equals(action)) {
+						BluetoothDevice d = i.getParcelableExtra(EXTRA_DEVICE);
+						String address = d.getAddress();
+						if (LOG.isLoggable(INFO))
+							LOG.info("Discovered " + scrubMacAddress(address));
+						if (!addresses.contains(address))
+							addresses.add(address);
+					}
+					now = clock.currentTimeMillis();
+				}
+			} else {
+				LOG.info("Could not start discovery");
+			}
+		} catch (InterruptedException e) {
+			LOG.info("Interrupted while discovering devices");
+			Thread.currentThread().interrupt();
+		} finally {
+			LOG.info("Cancelling discovery");
+			adapter.cancelDiscovery();
+			appContext.unregisterReceiver(receiver);
+		}
+		// Shuffle the addresses so we don't always try the same one first
+		Collections.shuffle(addresses);
+		return addresses;
+	}
+
+	private class BluetoothStateReceiver extends BroadcastReceiver {
+
+		@Override
+		public void onReceive(Context ctx, Intent intent) {
+			int state = intent.getIntExtra(EXTRA_STATE, 0);
+			if (state == STATE_ON) onAdapterEnabled();
+			else if (state == STATE_OFF) onAdapterDisabled();
+			int scanMode = intent.getIntExtra(EXTRA_SCAN_MODE, 0);
+			if (scanMode == SCAN_MODE_NONE) {
+				LOG.info("Scan mode: None");
+			} else if (scanMode == SCAN_MODE_CONNECTABLE) {
+				LOG.info("Scan mode: Connectable");
+			} else if (scanMode == SCAN_MODE_CONNECTABLE_DISCOVERABLE) {
+				LOG.info("Scan mode: Discoverable");
+			}
+		}
+	}
+
+	private static class DiscoveryReceiver extends BroadcastReceiver {
+
+		private final BlockingQueue<Intent> intents;
+
+		private DiscoveryReceiver(BlockingQueue<Intent> intents) {
+			this.intents = intents;
+		}
+
+		@Override
+		public void onReceive(Context ctx, Intent intent) {
+			intents.add(intent);
+		}
+	}
+}

bramble-android/src/main/java/org/briarproject/bramble/plugin/bluetooth/AndroidBluetoothPluginFactory.java

@@ -0,0 +1,75 @@
+package org.briarproject.bramble.plugin.bluetooth;
+
+import android.content.Context;
+
+import org.briarproject.bramble.api.event.EventBus;
+import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
+import org.briarproject.bramble.api.plugin.Backoff;
+import org.briarproject.bramble.api.plugin.BackoffFactory;
+import org.briarproject.bramble.api.plugin.PluginCallback;
+import org.briarproject.bramble.api.plugin.TransportId;
+import org.briarproject.bramble.api.plugin.duplex.DuplexPlugin;
+import org.briarproject.bramble.api.plugin.duplex.DuplexPluginFactory;
+import org.briarproject.bramble.api.system.AndroidExecutor;
+import org.briarproject.bramble.api.system.Clock;
+
+import java.security.SecureRandom;
+import java.util.concurrent.Executor;
+
+import javax.annotation.concurrent.Immutable;
+
+import static org.briarproject.bramble.api.plugin.BluetoothConstants.ID;
+
+@Immutable
+@NotNullByDefault
+public class AndroidBluetoothPluginFactory implements DuplexPluginFactory {
+
+	private static final int MAX_LATENCY = 30 * 1000; // 30 seconds
+	private static final int MIN_POLLING_INTERVAL = 60 * 1000; // 1 minute
+	private static final int MAX_POLLING_INTERVAL = 10 * 60 * 1000; // 10 mins
+	private static final double BACKOFF_BASE = 1.2;
+
+	private final Executor ioExecutor;
+	private final AndroidExecutor androidExecutor;
+	private final Context appContext;
+	private final SecureRandom secureRandom;
+	private final EventBus eventBus;
+	private final Clock clock;
+	private final BackoffFactory backoffFactory;
+
+	public AndroidBluetoothPluginFactory(Executor ioExecutor,
+			AndroidExecutor androidExecutor, Context appContext,
+			SecureRandom secureRandom, EventBus eventBus, Clock clock,
+			BackoffFactory backoffFactory) {
+		this.ioExecutor = ioExecutor;
+		this.androidExecutor = androidExecutor;
+		this.appContext = appContext;
+		this.secureRandom = secureRandom;
+		this.eventBus = eventBus;
+		this.clock = clock;
+		this.backoffFactory = backoffFactory;
+	}
+
+	@Override
+	public TransportId getId() {
+		return ID;
+	}
+
+	@Override
+	public int getMaxLatency() {
+		return MAX_LATENCY;
+	}
+
+	@Override
+	public DuplexPlugin createPlugin(PluginCallback callback) {
+		BluetoothConnectionLimiter connectionLimiter =
+				new BluetoothConnectionLimiterImpl();
+		Backoff backoff = backoffFactory.createBackoff(MIN_POLLING_INTERVAL,
+				MAX_POLLING_INTERVAL, BACKOFF_BASE);
+		AndroidBluetoothPlugin plugin = new AndroidBluetoothPlugin(
+				connectionLimiter, ioExecutor, androidExecutor, appContext,
+				secureRandom, clock, backoff, callback, MAX_LATENCY);
+		eventBus.addListener(plugin);
+		return plugin;
+	}
+}

bramble-android/src/main/java/org/briarproject/bramble/plugin/bluetooth/AndroidBluetoothTransportConnection.java

@@ -0,0 +1,46 @@
+package org.briarproject.bramble.plugin.bluetooth;
+
+import android.bluetooth.BluetoothSocket;
+
+import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
+import org.briarproject.bramble.api.plugin.Plugin;
+import org.briarproject.bramble.api.plugin.duplex.AbstractDuplexTransportConnection;
+
+import java.io.IOException;
+import java.io.InputStream;
+import java.io.OutputStream;
+
+@NotNullByDefault
+class AndroidBluetoothTransportConnection
+		extends AbstractDuplexTransportConnection {
+
+	private final BluetoothConnectionLimiter connectionManager;
+	private final BluetoothSocket socket;
+
+	AndroidBluetoothTransportConnection(Plugin plugin,
+			BluetoothConnectionLimiter connectionManager,
+			BluetoothSocket socket) {
+		super(plugin);
+		this.connectionManager = connectionManager;
+		this.socket = socket;
+	}
+
+	@Override
+	protected InputStream getInputStream() throws IOException {
+		return socket.getInputStream();
+	}
+
+	@Override
+	protected OutputStream getOutputStream() throws IOException {
+		return socket.getOutputStream();
+	}
+
+	@Override
+	protected void closeConnection(boolean exception) throws IOException {
+		try {
+			socket.close();
+		} finally {
+			connectionManager.connectionClosed(this);
+		}
+	}
+}

bramble-android/src/main/java/org/briarproject/bramble/plugin/tcp/AndroidLanTcpPlugin.java

@@ -0,0 +1,167 @@
+package org.briarproject.bramble.plugin.tcp;
+
+import android.content.Context;
+import android.net.ConnectivityManager;
+import android.net.Network;
+import android.net.NetworkInfo;
+import android.net.wifi.WifiInfo;
+import android.net.wifi.WifiManager;
+
+import org.briarproject.bramble.PoliteExecutor;
+import org.briarproject.bramble.api.event.Event;
+import org.briarproject.bramble.api.event.EventListener;
+import org.briarproject.bramble.api.network.event.NetworkStatusEvent;
+import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
+import org.briarproject.bramble.api.plugin.Backoff;
+import org.briarproject.bramble.api.plugin.PluginCallback;
+
+import java.io.IOException;
+import java.net.InetAddress;
+import java.net.Socket;
+import java.net.UnknownHostException;
+import java.util.Collection;
+import java.util.concurrent.Executor;
+import java.util.logging.Logger;
+
+import javax.annotation.Nullable;
+import javax.net.SocketFactory;
+
+import static android.content.Context.CONNECTIVITY_SERVICE;
+import static android.content.Context.WIFI_SERVICE;
+import static android.net.ConnectivityManager.TYPE_WIFI;
+import static android.os.Build.VERSION.SDK_INT;
+import static java.util.Collections.emptyList;
+import static java.util.Collections.singletonList;
+import static java.util.logging.Logger.getLogger;
+
+@NotNullByDefault
+class AndroidLanTcpPlugin extends LanTcpPlugin implements EventListener {
+
+	private static final Logger LOG =
+			getLogger(AndroidLanTcpPlugin.class.getName());
+
+	private static final byte[] WIFI_AP_ADDRESS_BYTES =
+			{(byte) 192, (byte) 168, 43, 1};
+	private static final InetAddress WIFI_AP_ADDRESS;
+
+	static {
+		try {
+			WIFI_AP_ADDRESS = InetAddress.getByAddress(WIFI_AP_ADDRESS_BYTES);
+		} catch (UnknownHostException e) {
+			// Should only be thrown if the address has an illegal length
+			throw new AssertionError(e);
+		}
+	}
+
+	private final Executor connectionStatusExecutor;
+	private final ConnectivityManager connectivityManager;
+	@Nullable
+	private final WifiManager wifiManager;
+
+	private volatile SocketFactory socketFactory;
+
+	AndroidLanTcpPlugin(Executor ioExecutor, Context appContext,
+			Backoff backoff, PluginCallback callback, int maxLatency,
+			int maxIdleTime) {
+		super(ioExecutor, backoff, callback, maxLatency, maxIdleTime);
+		// Don't execute more than one connection status check at a time
+		connectionStatusExecutor =
+				new PoliteExecutor("AndroidLanTcpPlugin", ioExecutor, 1);
+		ConnectivityManager connectivityManager = (ConnectivityManager)
+				appContext.getSystemService(CONNECTIVITY_SERVICE);
+		if (connectivityManager == null) throw new AssertionError();
+		this.connectivityManager = connectivityManager;
+		wifiManager = (WifiManager) appContext.getApplicationContext()
+				.getSystemService(WIFI_SERVICE);
+		socketFactory = SocketFactory.getDefault();
+	}
+
+	@Override
+	public void start() {
+		if (used.getAndSet(true)) throw new IllegalStateException();
+		running = true;
+		updateConnectionStatus();
+	}
+
+	@Override
+	public void stop() {
+		running = false;
+		tryToClose(socket);
+	}
+
+	@Override
+	protected Socket createSocket() throws IOException {
+		return socketFactory.createSocket();
+	}
+
+	@Override
+	protected Collection<InetAddress> getLocalIpAddresses() {
+		// If the device doesn't have wifi, don't open any sockets
+		if (wifiManager == null) return emptyList();
+		// If we're connected to a wifi network, use that network
+		WifiInfo info = wifiManager.getConnectionInfo();
+		if (info != null && info.getIpAddress() != 0)
+			return singletonList(intToInetAddress(info.getIpAddress()));
+		// If we're running an access point, return its address
+		if (super.getLocalIpAddresses().contains(WIFI_AP_ADDRESS))
+			return singletonList(WIFI_AP_ADDRESS);
+		// No suitable addresses
+		return emptyList();
+	}
+
+	private InetAddress intToInetAddress(int ip) {
+		byte[] ipBytes = new byte[4];
+		ipBytes[0] = (byte) (ip & 0xFF);
+		ipBytes[1] = (byte) ((ip >> 8) & 0xFF);
+		ipBytes[2] = (byte) ((ip >> 16) & 0xFF);
+		ipBytes[3] = (byte) ((ip >> 24) & 0xFF);
+		try {
+			return InetAddress.getByAddress(ipBytes);
+		} catch (UnknownHostException e) {
+			// Should only be thrown if address has illegal length
+			throw new AssertionError(e);
+		}
+	}
+
+	// On API 21 and later, a socket that is not created with the wifi
+	// network's socket factory may try to connect via another network
+	private SocketFactory getSocketFactory() {
+		if (SDK_INT < 21) return SocketFactory.getDefault();
+		for (Network net : connectivityManager.getAllNetworks()) {
+			NetworkInfo info = connectivityManager.getNetworkInfo(net);
+			if (info != null && info.getType() == TYPE_WIFI)
+				return net.getSocketFactory();
+		}
+		LOG.warning("Could not find suitable socket factory");
+		return SocketFactory.getDefault();
+	}
+
+	@Override
+	public void eventOccurred(Event e) {
+		if (e instanceof NetworkStatusEvent) updateConnectionStatus();
+	}
+
+	private void updateConnectionStatus() {
+		connectionStatusExecutor.execute(() -> {
+			if (!running) return;
+			Collection<InetAddress> addrs = getLocalIpAddresses();
+			if (addrs.contains(WIFI_AP_ADDRESS)) {
+				LOG.info("Providing wifi hotspot");
+				// There's no corresponding Network object and thus no way
+				// to get a suitable socket factory, so we won't be able to
+				// make outgoing connections on API 21+ if another network
+				// has internet access
+				socketFactory = SocketFactory.getDefault();
+				if (socket == null || socket.isClosed()) bind();
+			} else if (addrs.isEmpty()) {
+				LOG.info("Not connected to wifi");
+				socketFactory = SocketFactory.getDefault();
+				tryToClose(socket);
+			} else {
+				LOG.info("Connected to wifi");
+				socketFactory = getSocketFactory();
+				if (socket == null || socket.isClosed()) bind();
+			}
+		});
+	}
+}

bramble-android/src/main/java/org/briarproject/bramble/plugin/tcp/AndroidLanTcpPluginFactory.java

@@ -0,0 +1,62 @@
+package org.briarproject.bramble.plugin.tcp;
+
+import android.content.Context;
+
+import org.briarproject.bramble.api.event.EventBus;
+import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
+import org.briarproject.bramble.api.plugin.Backoff;
+import org.briarproject.bramble.api.plugin.BackoffFactory;
+import org.briarproject.bramble.api.plugin.PluginCallback;
+import org.briarproject.bramble.api.plugin.TransportId;
+import org.briarproject.bramble.api.plugin.duplex.DuplexPlugin;
+import org.briarproject.bramble.api.plugin.duplex.DuplexPluginFactory;
+
+import java.util.concurrent.Executor;
+
+import javax.annotation.concurrent.Immutable;
+
+import static org.briarproject.bramble.api.plugin.LanTcpConstants.ID;
+
+@Immutable
+@NotNullByDefault
+public class AndroidLanTcpPluginFactory implements DuplexPluginFactory {
+
+	private static final int MAX_LATENCY = 30 * 1000; // 30 seconds
+	private static final int MAX_IDLE_TIME = 30 * 1000; // 30 seconds
+	private static final int MIN_POLLING_INTERVAL = 60 * 1000; // 1 minute
+	private static final int MAX_POLLING_INTERVAL = 10 * 60 * 1000; // 10 mins
+	private static final double BACKOFF_BASE = 1.2;
+
+	private final Executor ioExecutor;
+	private final EventBus eventBus;
+	private final BackoffFactory backoffFactory;
+	private final Context appContext;
+
+	public AndroidLanTcpPluginFactory(Executor ioExecutor, EventBus eventBus,
+			BackoffFactory backoffFactory, Context appContext) {
+		this.ioExecutor = ioExecutor;
+		this.eventBus = eventBus;
+		this.backoffFactory = backoffFactory;
+		this.appContext = appContext;
+	}
+
+	@Override
+	public TransportId getId() {
+		return ID;
+	}
+
+	@Override
+	public int getMaxLatency() {
+		return MAX_LATENCY;
+	}
+
+	@Override
+	public DuplexPlugin createPlugin(PluginCallback callback) {
+		Backoff backoff = backoffFactory.createBackoff(MIN_POLLING_INTERVAL,
+				MAX_POLLING_INTERVAL, BACKOFF_BASE);
+		AndroidLanTcpPlugin plugin = new AndroidLanTcpPlugin(ioExecutor,
+				appContext, backoff, callback, MAX_LATENCY, MAX_IDLE_TIME);
+		eventBus.addListener(plugin);
+		return plugin;
+	}
+}

bramble-android/src/main/java/org/briarproject/bramble/plugin/tor/AndroidTorPlugin.java

@@ -0,0 +1,101 @@
+package org.briarproject.bramble.plugin.tor;
+
+import android.content.Context;
+import android.content.pm.PackageInfo;
+import android.content.pm.PackageManager;
+import android.content.pm.PackageManager.NameNotFoundException;
+import android.os.PowerManager;
+
+import org.briarproject.bramble.api.battery.BatteryManager;
+import org.briarproject.bramble.api.network.NetworkManager;
+import org.briarproject.bramble.api.nullsafety.MethodsNotNullByDefault;
+import org.briarproject.bramble.api.nullsafety.ParametersNotNullByDefault;
+import org.briarproject.bramble.api.plugin.Backoff;
+import org.briarproject.bramble.api.plugin.PluginCallback;
+import org.briarproject.bramble.api.system.Clock;
+import org.briarproject.bramble.api.system.LocationUtils;
+import org.briarproject.bramble.api.system.ResourceProvider;
+import org.briarproject.bramble.util.RenewableWakeLock;
+
+import java.io.IOException;
+import java.util.concurrent.Executor;
+import java.util.concurrent.ScheduledExecutorService;
+
+import javax.net.SocketFactory;
+
+import static android.content.Context.MODE_PRIVATE;
+import static android.content.Context.POWER_SERVICE;
+import static android.os.PowerManager.PARTIAL_WAKE_LOCK;
+import static java.util.concurrent.TimeUnit.MINUTES;
+
+@MethodsNotNullByDefault
+@ParametersNotNullByDefault
+class AndroidTorPlugin extends TorPlugin {
+
+	private final Context appContext;
+	private final RenewableWakeLock wakeLock;
+
+	AndroidTorPlugin(Executor ioExecutor, ScheduledExecutorService scheduler,
+			Context appContext, NetworkManager networkManager,
+			LocationUtils locationUtils, SocketFactory torSocketFactory,
+			Clock clock, ResourceProvider resourceProvider,
+			CircumventionProvider circumventionProvider,
+			BatteryManager batteryManager, Backoff backoff,
+			TorRendezvousCrypto torRendezvousCrypto,
+			PluginCallback callback, String architecture, int maxLatency,
+			int maxIdleTime) {
+		super(ioExecutor, networkManager, locationUtils, torSocketFactory,
+				clock, resourceProvider, circumventionProvider, batteryManager,
+				backoff, torRendezvousCrypto, callback, architecture, maxLatency, maxIdleTime,
+				appContext.getDir("tor", MODE_PRIVATE));
+		this.appContext = appContext;
+		PowerManager pm = (PowerManager)
+				appContext.getSystemService(POWER_SERVICE);
+		if (pm == null) throw new AssertionError();
+		wakeLock = new RenewableWakeLock(pm, scheduler, PARTIAL_WAKE_LOCK,
+				getWakeLockTag(), 1, MINUTES);
+	}
+
+	@Override
+	protected int getProcessId() {
+		return android.os.Process.myPid();
+	}
+
+	@Override
+	protected long getLastUpdateTime() {
+		try {
+			PackageManager pm = appContext.getPackageManager();
+			PackageInfo pi = pm.getPackageInfo(appContext.getPackageName(), 0);
+			return pi.lastUpdateTime;
+		} catch (NameNotFoundException e) {
+			throw new AssertionError(e);
+		}
+	}
+
+	@Override
+	protected void enableNetwork(boolean enable) throws IOException {
+		if (!running) return;
+		if (enable) wakeLock.acquire();
+		super.enableNetwork(enable);
+		if (!enable) wakeLock.release();
+	}
+
+	@Override
+	public void stop() {
+		super.stop();
+		wakeLock.release();
+	}
+
+	private String getWakeLockTag() {
+		PackageManager pm = appContext.getPackageManager();
+		for (PackageInfo info : pm.getInstalledPackages(0)) {
+			String name = info.packageName.toLowerCase();
+			if (name.startsWith("com.huawei.powergenie")) {
+				return "LocationManagerService";
+			} else if (name.startsWith("com.evenwell.powermonitor")) {
+				return "AudioIn";
+			}
+		}
+		return getClass().getSimpleName();
+	}
+}

bramble-android/src/main/java/org/briarproject/bramble/plugin/tor/AndroidTorPluginFactory.java

@@ -0,0 +1,123 @@
+package org.briarproject.bramble.plugin.tor;
+
+import android.content.Context;
+
+import org.briarproject.bramble.api.battery.BatteryManager;
+import org.briarproject.bramble.api.event.EventBus;
+import org.briarproject.bramble.api.network.NetworkManager;
+import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
+import org.briarproject.bramble.api.plugin.Backoff;
+import org.briarproject.bramble.api.plugin.BackoffFactory;
+import org.briarproject.bramble.api.plugin.PluginCallback;
+import org.briarproject.bramble.api.plugin.TorConstants;
+import org.briarproject.bramble.api.plugin.TransportId;
+import org.briarproject.bramble.api.plugin.duplex.DuplexPlugin;
+import org.briarproject.bramble.api.plugin.duplex.DuplexPluginFactory;
+import org.briarproject.bramble.api.system.Clock;
+import org.briarproject.bramble.api.system.LocationUtils;
+import org.briarproject.bramble.api.system.ResourceProvider;
+import org.briarproject.bramble.util.AndroidUtils;
+
+import java.util.concurrent.Executor;
+import java.util.concurrent.ScheduledExecutorService;
+import java.util.logging.Logger;
+
+import javax.annotation.concurrent.Immutable;
+import javax.net.SocketFactory;
+
+@Immutable
+@NotNullByDefault
+public class AndroidTorPluginFactory implements DuplexPluginFactory {
+
+	private static final Logger LOG =
+			Logger.getLogger(AndroidTorPluginFactory.class.getName());
+
+	private static final int MAX_LATENCY = 30 * 1000; // 30 seconds
+	private static final int MAX_IDLE_TIME = 30 * 1000; // 30 seconds
+	private static final int MIN_POLLING_INTERVAL = 60 * 1000; // 1 minute
+	private static final int MAX_POLLING_INTERVAL = 10 * 60 * 1000; // 10 mins
+	private static final double BACKOFF_BASE = 1.2;
+
+	private final Executor ioExecutor;
+	private final ScheduledExecutorService scheduler;
+	private final Context appContext;
+	private final NetworkManager networkManager;
+	private final LocationUtils locationUtils;
+	private final EventBus eventBus;
+	private final SocketFactory torSocketFactory;
+	private final BackoffFactory backoffFactory;
+	private final ResourceProvider resourceProvider;
+	private final CircumventionProvider circumventionProvider;
+	private final BatteryManager batteryManager;
+	private final Clock clock;
+
+	public AndroidTorPluginFactory(Executor ioExecutor,
+			ScheduledExecutorService scheduler, Context appContext,
+			NetworkManager networkManager, LocationUtils locationUtils,
+			EventBus eventBus, SocketFactory torSocketFactory,
+			BackoffFactory backoffFactory, ResourceProvider resourceProvider,
+			CircumventionProvider circumventionProvider,
+			BatteryManager batteryManager, Clock clock) {
+		this.ioExecutor = ioExecutor;
+		this.scheduler = scheduler;
+		this.appContext = appContext;
+		this.networkManager = networkManager;
+		this.locationUtils = locationUtils;
+		this.eventBus = eventBus;
+		this.torSocketFactory = torSocketFactory;
+		this.backoffFactory = backoffFactory;
+		this.resourceProvider = resourceProvider;
+		this.circumventionProvider = circumventionProvider;
+		this.batteryManager = batteryManager;
+		this.clock = clock;
+	}
+
+	@Override
+	public TransportId getId() {
+		return TorConstants.ID;
+	}
+
+	@Override
+	public int getMaxLatency() {
+		return MAX_LATENCY;
+	}
+
+	@Override
+	public DuplexPlugin createPlugin(PluginCallback callback) {
+
+		// Check that we have a Tor binary for this architecture
+		String architecture = null;
+		for (String abi : AndroidUtils.getSupportedArchitectures()) {
+			if (abi.startsWith("x86_64")) {
+				architecture = "x86_64";
+				break;
+			} else if (abi.startsWith("x86")) {
+				architecture = "x86";
+				break;
+			} else if (abi.startsWith("arm64")) {
+				architecture = "arm64";
+				break;
+			} else if (abi.startsWith("armeabi")) {
+				architecture = "arm";
+				break;
+			}
+		}
+		if (architecture == null) {
+			LOG.info("Tor is not supported on this architecture");
+			return null;
+		}
+		// Use position-independent executable
+		architecture += "_pie";
+
+		Backoff backoff = backoffFactory.createBackoff(MIN_POLLING_INTERVAL,
+				MAX_POLLING_INTERVAL, BACKOFF_BASE);
+		TorRendezvousCrypto torRendezvousCrypto = new TorRendezvousCryptoImpl();
+		AndroidTorPlugin plugin = new AndroidTorPlugin(ioExecutor, scheduler,
+				appContext, networkManager, locationUtils, torSocketFactory,
+				clock, resourceProvider, circumventionProvider, batteryManager,
+				backoff, torRendezvousCrypto, callback, architecture,
+				MAX_LATENCY, MAX_IDLE_TIME);
+		eventBus.addListener(plugin);
+		return plugin;
+	}
+}

bramble-android/src/main/java/org/briarproject/bramble/system/AndroidExecutorImpl.java

@@ -0,0 +1,75 @@
+package org.briarproject.bramble.system;
+
+import android.app.Application;
+import android.os.Handler;
+import android.os.Looper;
+
+import org.briarproject.bramble.api.system.AndroidExecutor;
+
+import java.util.concurrent.Callable;
+import java.util.concurrent.CountDownLatch;
+import java.util.concurrent.Future;
+import java.util.concurrent.FutureTask;
+import java.util.concurrent.RejectedExecutionException;
+import java.util.concurrent.atomic.AtomicBoolean;
+
+import javax.inject.Inject;
+
+class AndroidExecutorImpl implements AndroidExecutor {
+
+	private final Handler uiHandler;
+	private final Runnable loop;
+	private final AtomicBoolean started = new AtomicBoolean(false);
+	private final CountDownLatch startLatch = new CountDownLatch(1);
+
+	private volatile Handler backgroundHandler = null;
+
+	@Inject
+	AndroidExecutorImpl(Application app) {
+		uiHandler = new Handler(app.getApplicationContext().getMainLooper());
+		loop = () -> {
+			Looper.prepare();
+			backgroundHandler = new Handler();
+			startLatch.countDown();
+			Looper.loop();
+		};
+	}
+
+	private void startIfNecessary() {
+		if (!started.getAndSet(true)) {
+			Thread t = new Thread(loop, "AndroidExecutor");
+			t.setDaemon(true);
+			t.start();
+		}
+		try {
+			startLatch.await();
+		} catch (InterruptedException e) {
+			throw new RejectedExecutionException(e);
+		}
+	}
+
+	@Override
+	public <V> Future<V> runOnBackgroundThread(Callable<V> c) {
+		FutureTask<V> f = new FutureTask<>(c);
+		runOnBackgroundThread(f);
+		return f;
+	}
+
+	@Override
+	public void runOnBackgroundThread(Runnable r) {
+		startIfNecessary();
+		backgroundHandler.post(r);
+	}
+
+	@Override
+	public <V> Future<V> runOnUiThread(Callable<V> c) {
+		FutureTask<V> f = new FutureTask<>(c);
+		runOnUiThread(f);
+		return f;
+	}
+
+	@Override
+	public void runOnUiThread(Runnable r) {
+		uiHandler.post(r);
+	}
+}

bramble-android/src/main/java/org/briarproject/bramble/system/AndroidLocationUtils.java

@@ -1,4 +1,4 @@
-package org.briarproject.system;
+package org.briarproject.bramble.system;
 
 import android.annotation.SuppressLint;
 import android.app.Application;
@@ -6,7 +6,8 @@ import android.content.Context;
 import android.telephony.TelephonyManager;
 import android.text.TextUtils;
 
-import org.briarproject.api.system.LocationUtils;
+import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
+import org.briarproject.bramble.api.system.LocationUtils;
 
 import java.util.Locale;
 import java.util.logging.Logger;
@@ -15,6 +16,7 @@ import javax.inject.Inject;
 
 import static android.content.Context.TELEPHONY_SERVICE;
 
+@NotNullByDefault
 class AndroidLocationUtils implements LocationUtils {
 
 	private static final Logger LOG =
@@ -23,7 +25,7 @@ class AndroidLocationUtils implements LocationUtils {
 	private final Context appContext;
 
 	@Inject
-	public AndroidLocationUtils(Application app) {
+	AndroidLocationUtils(Application app) {
 		appContext = app.getApplicationContext();
 	}
 
@@ -44,6 +46,7 @@ class AndroidLocationUtils implements LocationUtils {
 	 * some reason - both that class and {@code Context.COUNTRY_CODE} are
 	 * annotated {@code @hide}.
 	 */
+	@Override
 	@SuppressLint("DefaultLocale")
 	public String getCurrentCountry() {
 		String countryCode = getCountryFromPhoneNetwork();

bramble-android/src/main/java/org/briarproject/bramble/system/AndroidResourceProvider.java

@@ -0,0 +1,32 @@
+package org.briarproject.bramble.system;
+
+import android.app.Application;
+import android.content.Context;
+import android.content.res.Resources;
+
+import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
+import org.briarproject.bramble.api.system.ResourceProvider;
+
+import java.io.InputStream;
+
+import javax.inject.Inject;
+
+@NotNullByDefault
+class AndroidResourceProvider implements ResourceProvider {
+
+	private final Context appContext;
+
+	@Inject
+	AndroidResourceProvider(Application app) {
+		this.appContext = app.getApplicationContext();
+	}
+
+	@Override
+	public InputStream getResourceInputStream(String name, String extension) {
+		Resources res = appContext.getResources();
+		// extension is ignored on Android, resources are retrieved without it
+		int resId =
+				res.getIdentifier(name, "raw", appContext.getPackageName());
+		return res.openRawResource(resId);
+	}
+}

bramble-android/src/main/java/org/briarproject/bramble/system/AndroidSecureRandomProvider.java

@@ -0,0 +1,101 @@
+package org.briarproject.bramble.system;
+
+import android.annotation.SuppressLint;
+import android.app.Application;
+import android.bluetooth.BluetoothAdapter;
+import android.bluetooth.BluetoothDevice;
+import android.content.ContentResolver;
+import android.content.Context;
+import android.net.wifi.WifiConfiguration;
+import android.net.wifi.WifiManager;
+import android.os.Build;
+import android.os.Parcel;
+import android.os.StrictMode;
+import android.provider.Settings;
+
+import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
+
+import java.io.DataOutputStream;
+import java.io.IOException;
+import java.util.List;
+
+import javax.annotation.concurrent.Immutable;
+import javax.inject.Inject;
+
+import static android.content.Context.WIFI_SERVICE;
+import static android.os.Build.VERSION.SDK_INT;
+import static android.provider.Settings.Secure.ANDROID_ID;
+
+@Immutable
+@NotNullByDefault
+class AndroidSecureRandomProvider extends UnixSecureRandomProvider {
+
+	private static final int SEED_LENGTH = 32;
+
+	private final Context appContext;
+
+	@Inject
+	AndroidSecureRandomProvider(Application app) {
+		appContext = app.getApplicationContext();
+	}
+
+	@SuppressLint("HardwareIds")
+	@Override
+	protected void writeToEntropyPool(DataOutputStream out) throws IOException {
+		super.writeToEntropyPool(out);
+		out.writeInt(android.os.Process.myPid());
+		out.writeInt(android.os.Process.myTid());
+		out.writeInt(android.os.Process.myUid());
+		if (Build.FINGERPRINT != null) out.writeUTF(Build.FINGERPRINT);
+		if (Build.SERIAL != null) out.writeUTF(Build.SERIAL);
+		ContentResolver contentResolver = appContext.getContentResolver();
+		String id = Settings.Secure.getString(contentResolver, ANDROID_ID);
+		if (id != null) out.writeUTF(id);
+		Parcel parcel = Parcel.obtain();
+		WifiManager wm = (WifiManager) appContext.getApplicationContext()
+				.getSystemService(WIFI_SERVICE);
+		if (wm != null) {
+			List<WifiConfiguration> configs = wm.getConfiguredNetworks();
+			if (configs != null) {
+				for (WifiConfiguration config : configs)
+					parcel.writeParcelable(config, 0);
+			}
+		}
+		BluetoothAdapter bt = BluetoothAdapter.getDefaultAdapter();
+		if (bt != null) {
+			for (BluetoothDevice device : bt.getBondedDevices())
+				parcel.writeParcelable(device, 0);
+		}
+		out.write(parcel.marshall());
+		parcel.recycle();
+	}
+
+	@Override
+	protected void writeSeed() {
+		// Silence strict mode
+		StrictMode.ThreadPolicy tp = StrictMode.allowThreadDiskWrites();
+		super.writeSeed();
+		if (SDK_INT <= 18) applyOpenSslFix();
+		StrictMode.setThreadPolicy(tp);
+	}
+
+	// Based on https://android-developers.googleblog.com/2013/08/some-securerandom-thoughts.html
+	private void applyOpenSslFix() {
+		byte[] seed = new UnixSecureRandomSpi().engineGenerateSeed(
+				SEED_LENGTH);
+		try {
+			// Seed the OpenSSL PRNG
+			Class.forName("org.apache.harmony.xnet.provider.jsse.NativeCrypto")
+					.getMethod("RAND_seed", byte[].class)
+					.invoke(null, (Object) seed);
+			// Mix the output of the Linux PRNG into the OpenSSL PRNG
+			int bytesRead = (Integer) Class.forName(
+					"org.apache.harmony.xnet.provider.jsse.NativeCrypto")
+					.getMethod("RAND_load_file", String.class, long.class)
+					.invoke(null, "/dev/urandom", 1024);
+			if (bytesRead != 1024) throw new IOException();
+		} catch (Exception e) {
+			throw new SecurityException(e);
+		}
+	}
+}

bramble-android/src/main/java/org/briarproject/bramble/system/AndroidSystemModule.java

@@ -0,0 +1,50 @@
+package org.briarproject.bramble.system;
+
+import org.briarproject.bramble.api.event.EventExecutor;
+import org.briarproject.bramble.api.system.AndroidExecutor;
+import org.briarproject.bramble.api.system.LocationUtils;
+import org.briarproject.bramble.api.system.ResourceProvider;
+import org.briarproject.bramble.api.system.SecureRandomProvider;
+
+import java.util.concurrent.Executor;
+
+import javax.inject.Singleton;
+
+import dagger.Module;
+import dagger.Provides;
+
+@Module
+public class AndroidSystemModule {
+
+	@Provides
+	@Singleton
+	SecureRandomProvider provideSecureRandomProvider(
+			AndroidSecureRandomProvider provider) {
+		return provider;
+	}
+
+	@Provides
+	LocationUtils provideLocationUtils(AndroidLocationUtils locationUtils) {
+		return locationUtils;
+	}
+
+	@Provides
+	@Singleton
+	AndroidExecutor provideAndroidExecutor(
+			AndroidExecutorImpl androidExecutor) {
+		return androidExecutor;
+	}
+
+	@Provides
+	@Singleton
+	@EventExecutor
+	Executor provideEventExecutor(AndroidExecutor androidExecutor) {
+		return androidExecutor::runOnUiThread;
+	}
+
+	@Provides
+	@Singleton
+	ResourceProvider provideResourceProvider(AndroidResourceProvider provider) {
+		return provider;
+	}
+}

bramble-android/src/main/java/org/briarproject/bramble/util/AndroidUtils.java

@@ -0,0 +1,120 @@
+package org.briarproject.bramble.util;
+
+import android.annotation.SuppressLint;
+import android.bluetooth.BluetoothAdapter;
+import android.content.Context;
+import android.os.Build;
+import android.provider.Settings;
+
+import org.briarproject.bramble.api.Pair;
+import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
+
+import java.io.File;
+import java.lang.reflect.Field;
+import java.lang.reflect.InvocationTargetException;
+import java.lang.reflect.Method;
+import java.util.ArrayList;
+import java.util.Collection;
+import java.util.List;
+
+import javax.annotation.Nullable;
+
+import static android.content.Context.MODE_PRIVATE;
+import static android.os.Build.VERSION.SDK_INT;
+import static java.util.Arrays.asList;
+import static org.briarproject.bramble.api.nullsafety.NullSafety.requireNonNull;
+
+@NotNullByDefault
+public class AndroidUtils {
+
+	// Fake Bluetooth address returned by BluetoothAdapter on API 23 and later
+	private static final String FAKE_BLUETOOTH_ADDRESS = "02:00:00:00:00:00";
+
+	private static final String STORED_REPORTS = "dev-reports";
+
+	public static Collection<String> getSupportedArchitectures() {
+		List<String> abis = new ArrayList<>();
+		if (SDK_INT >= 21) {
+			abis.addAll(asList(Build.SUPPORTED_ABIS));
+		} else {
+			abis.add(Build.CPU_ABI);
+			if (Build.CPU_ABI2 != null) abis.add(Build.CPU_ABI2);
+		}
+		return abis;
+	}
+
+	public static String getBluetoothAddress(Context ctx,
+			BluetoothAdapter adapter) {
+		return getBluetoothAddressAndMethod(ctx, adapter).getFirst();
+	}
+
+	public static Pair<String, String> getBluetoothAddressAndMethod(Context ctx,
+			BluetoothAdapter adapter) {
+		// Return the adapter's address if it's valid and not fake
+		@SuppressLint("HardwareIds")
+		String address = adapter.getAddress();
+		if (isValidBluetoothAddress(address)) {
+			return new Pair<>(address, "adapter");
+		}
+		// Return the address from settings if it's valid and not fake
+		address = Settings.Secure.getString(ctx.getContentResolver(),
+				"bluetooth_address");
+		if (isValidBluetoothAddress(address)) {
+			return new Pair<>(address, "settings");
+		}
+		// Try to get the address via reflection
+		address = getBluetoothAddressByReflection(adapter);
+		if (isValidBluetoothAddress(address)) {
+			return new Pair<>(requireNonNull(address), "reflection");
+		}
+		// Let the caller know we can't find the address
+		return new Pair<>("", "");
+	}
+
+	private static boolean isValidBluetoothAddress(@Nullable String address) {
+		return !StringUtils.isNullOrEmpty(address)
+				&& BluetoothAdapter.checkBluetoothAddress(address)
+				&& !address.equals(FAKE_BLUETOOTH_ADDRESS);
+	}
+
+	@Nullable
+	private static String getBluetoothAddressByReflection(
+			BluetoothAdapter adapter) {
+		try {
+			Field mServiceField =
+					adapter.getClass().getDeclaredField("mService");
+			mServiceField.setAccessible(true);
+			Object mService = mServiceField.get(adapter);
+			// mService may be null when Bluetooth is disabled
+			if (mService == null) throw new NoSuchFieldException();
+			Method getAddressMethod =
+					mService.getClass().getMethod("getAddress");
+			return (String) getAddressMethod.invoke(mService);
+		} catch (NoSuchFieldException e) {
+			return null;
+		} catch (IllegalAccessException e) {
+			return null;
+		} catch (NoSuchMethodException e) {
+			return null;
+		} catch (InvocationTargetException e) {
+			return null;
+		} catch (SecurityException e) {
+			return null;
+		}
+	}
+
+	public static File getReportDir(Context ctx) {
+		return ctx.getDir(STORED_REPORTS, MODE_PRIVATE);
+	}
+
+	/**
+	 * Returns an array of supported content types for image attachments.
+	 * GIFs can't be compressed on API < 24 so they're not supported.
+	 * <p>
+	 * TODO: Remove this restriction when large message support is added
+	 */
+	public static String[] getSupportedImageContentTypes() {
+		if (SDK_INT < 24) return new String[] {"image/jpeg", "image/png"};
+		else return new String[] {"image/jpeg", "image/png", "image/gif"};
+	}
+}

bramble-android/src/main/java/org/briarproject/bramble/util/RenewableWakeLock.java

@@ -0,0 +1,100 @@
+package org.briarproject.bramble.util;
+
+import android.os.PowerManager;
+
+import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
+
+import java.util.concurrent.ScheduledExecutorService;
+import java.util.concurrent.ScheduledFuture;
+import java.util.concurrent.TimeUnit;
+import java.util.logging.Logger;
+
+import javax.annotation.Nullable;
+import javax.annotation.concurrent.ThreadSafe;
+
+import static java.util.concurrent.TimeUnit.MILLISECONDS;
+import static java.util.logging.Level.INFO;
+
+@ThreadSafe
+@NotNullByDefault
+public class RenewableWakeLock {
+
+	private static final Logger LOG =
+			Logger.getLogger(RenewableWakeLock.class.getName());
+
+	/**
+	 * Automatically release the lock this many milliseconds after it's due
+	 * to have been replaced and released.
+	 */
+	private static final int SAFETY_MARGIN_MS = 10_000;
+
+	private final PowerManager powerManager;
+	private final ScheduledExecutorService scheduler;
+	private final int levelAndFlags;
+	private final String tag;
+	private final long durationMs;
+	private final Runnable renewTask;
+
+	private final Object lock = new Object();
+	@Nullable
+	private PowerManager.WakeLock wakeLock; // Locking: lock
+	@Nullable
+	private ScheduledFuture future; // Locking: lock
+
+	public RenewableWakeLock(PowerManager powerManager,
+			ScheduledExecutorService scheduler, int levelAndFlags, String tag,
+			long duration, TimeUnit timeUnit) {
+		this.powerManager = powerManager;
+		this.scheduler = scheduler;
+		this.levelAndFlags = levelAndFlags;
+		this.tag = tag;
+		durationMs = MILLISECONDS.convert(duration, timeUnit);
+		renewTask = this::renew;
+	}
+
+	public void acquire() {
+		if (LOG.isLoggable(INFO)) LOG.info("Acquiring wake lock " + tag);
+		synchronized (lock) {
+			if (wakeLock != null) {
+				LOG.info("Already acquired");
+				return;
+			}
+			wakeLock = powerManager.newWakeLock(levelAndFlags, tag);
+			wakeLock.setReferenceCounted(false);
+			wakeLock.acquire(durationMs + SAFETY_MARGIN_MS);
+			future = scheduler.schedule(renewTask, durationMs, MILLISECONDS);
+		}
+	}
+
+	private void renew() {
+		if (LOG.isLoggable(INFO)) LOG.info("Renewing wake lock " + tag);
+		synchronized (lock) {
+			if (wakeLock == null) {
+				LOG.info("Already released");
+				return;
+			}
+			PowerManager.WakeLock oldWakeLock = wakeLock;
+			wakeLock = powerManager.newWakeLock(levelAndFlags, tag);
+			wakeLock.setReferenceCounted(false);
+			wakeLock.acquire(durationMs + SAFETY_MARGIN_MS);
+			oldWakeLock.release();
+			future = scheduler.schedule(renewTask, durationMs, MILLISECONDS);
+		}
+	}
+
+	public void release() {
+		if (LOG.isLoggable(INFO)) LOG.info("Releasing wake lock " + tag);
+		synchronized (lock) {
+			if (wakeLock == null) {
+				LOG.info("Already released");
+				return;
+			}
+			if (future == null) throw new AssertionError();
+			future.cancel(false);
+			future = null;
+			wakeLock.release();
+			wakeLock = null;
+		}
+	}
+}
+

bramble-android/src/main/res/values/strings.xml

@@ -0,0 +1,3 @@
+<resources>
+	<string name="app_name">Bramble</string>
+</resources>

bramble-android/src/test/java/org/briarproject/bramble/account/AndroidAccountManagerTest.java

@@ -0,0 +1,145 @@
+package org.briarproject.bramble.account;
+
+import android.app.Application;
+import android.content.SharedPreferences;
+import android.content.pm.ApplicationInfo;
+
+import org.briarproject.bramble.api.crypto.CryptoComponent;
+import org.briarproject.bramble.api.db.DatabaseConfig;
+import org.briarproject.bramble.api.identity.IdentityManager;
+import org.briarproject.bramble.test.BrambleMockTestCase;
+import org.jmock.Expectations;
+import org.jmock.lib.legacy.ClassImposteriser;
+import org.junit.After;
+import org.junit.Before;
+import org.junit.Test;
+
+import java.io.File;
+
+import static junit.framework.Assert.assertFalse;
+import static junit.framework.Assert.assertTrue;
+import static org.briarproject.bramble.test.TestUtils.deleteTestDirectory;
+import static org.briarproject.bramble.test.TestUtils.getTestDirectory;
+
+public class AndroidAccountManagerTest extends BrambleMockTestCase {
+
+	private final SharedPreferences prefs =
+			context.mock(SharedPreferences.class, "prefs");
+	private final SharedPreferences defaultPrefs =
+			context.mock(SharedPreferences.class, "defaultPrefs");
+	private final DatabaseConfig databaseConfig =
+			context.mock(DatabaseConfig.class);
+	private final CryptoComponent crypto = context.mock(CryptoComponent.class);
+	private final IdentityManager identityManager =
+			context.mock(IdentityManager.class);
+	private final SharedPreferences.Editor
+			editor = context.mock(SharedPreferences.Editor.class);
+	private final Application app;
+	private final ApplicationInfo applicationInfo;
+
+	private final File testDir = getTestDirectory();
+	private final File keyDir = new File(testDir, "key");
+	private final File dbDir = new File(testDir, "db");
+
+	private AndroidAccountManager accountManager;
+
+	public AndroidAccountManagerTest() {
+		context.setImposteriser(ClassImposteriser.INSTANCE);
+		app = context.mock(Application.class);
+		applicationInfo = new ApplicationInfo();
+		applicationInfo.dataDir = testDir.getAbsolutePath();
+	}
+
+	@Before
+	public void setUp() {
+		context.checking(new Expectations() {{
+			allowing(databaseConfig).getDatabaseDirectory();
+			will(returnValue(dbDir));
+			allowing(databaseConfig).getDatabaseKeyDirectory();
+			will(returnValue(keyDir));
+			allowing(app).getApplicationContext();
+			will(returnValue(app));
+		}});
+		accountManager = new AndroidAccountManager(databaseConfig, crypto,
+				identityManager, prefs, app) {
+			@Override
+			SharedPreferences getDefaultSharedPreferences() {
+				return defaultPrefs;
+			}
+		};
+	}
+
+	@Test
+	public void testDeleteAccountClearsSharedPrefsAndDeletesFiles()
+			throws Exception {
+		// Directories 'lib' and 'shared_prefs' should be spared
+		File libDir = new File(testDir, "lib");
+		File libFile = new File(libDir, "file");
+		File sharedPrefsDir = new File(testDir, "shared_prefs");
+		File sharedPrefsFile = new File(sharedPrefsDir, "file");
+		// Directory 'cache' should be emptied
+		File cacheDir = new File(testDir, "cache");
+		File cacheFile = new File(cacheDir, "file");
+		// Other directories should be deleted
+		File potatoDir = new File(testDir, ".potato");
+		File potatoFile = new File(potatoDir, "file");
+		File filesDir = new File(testDir, "filesDir");
+		File externalCacheDir = new File(testDir, "externalCacheDir");
+
+		context.checking(new Expectations() {{
+			oneOf(prefs).edit();
+			will(returnValue(editor));
+			oneOf(editor).clear();
+			will(returnValue(editor));
+			oneOf(editor).commit();
+			will(returnValue(true));
+			oneOf(defaultPrefs).edit();
+			will(returnValue(editor));
+			oneOf(editor).clear();
+			will(returnValue(editor));
+			oneOf(editor).commit();
+			will(returnValue(true));
+			allowing(app).getApplicationInfo();
+			will(returnValue(applicationInfo));
+			oneOf(app).getFilesDir();
+			will(returnValue(filesDir));
+			oneOf(app).getCacheDir();
+			will(returnValue(cacheDir));
+			oneOf(app).getExternalCacheDir();
+			will(returnValue(externalCacheDir));
+		}});
+
+		assertTrue(dbDir.mkdirs());
+		assertTrue(keyDir.mkdirs());
+		assertTrue(libDir.mkdirs());
+		assertTrue(libFile.createNewFile());
+		assertTrue(sharedPrefsDir.mkdirs());
+		assertTrue(sharedPrefsFile.createNewFile());
+		assertTrue(cacheDir.mkdirs());
+		assertTrue(cacheFile.createNewFile());
+		assertTrue(potatoDir.mkdirs());
+		assertTrue(potatoFile.createNewFile());
+		assertTrue(filesDir.mkdirs());
+		assertTrue(externalCacheDir.mkdirs());
+
+		accountManager.deleteAccount();
+
+		assertFalse(dbDir.exists());
+		assertFalse(keyDir.exists());
+		assertTrue(libDir.exists());
+		assertTrue(libFile.exists());
+		assertTrue(sharedPrefsDir.exists());
+		assertTrue(sharedPrefsFile.exists());
+		assertTrue(cacheDir.exists());
+		assertFalse(cacheFile.exists());
+		assertFalse(potatoDir.exists());
+		assertFalse(potatoFile.exists());
+		assertFalse(filesDir.exists());
+		assertFalse(externalCacheDir.exists());
+	}
+
+	@After
+	public void tearDown() {
+		deleteTestDirectory(testDir);
+	}
+}

bramble-android/witness.gradle

@@ -0,0 +1,103 @@
+dependencyVerification {
+    verify = [
+        'cglib:cglib:3.2.0:cglib-3.2.0.jar:adb13bab79712ad6bdf1bd59f2a3918018a8016e722e8a357065afb9e6690861',
+        'com.android.tools.analytics-library:protos:26.5.1:protos-26.5.1.jar:8dde1130725461fe827f2a343d353f2b51e8870661fc860d7d5ebddb097ead4e',
+        'com.android.tools.analytics-library:shared:26.5.1:shared-26.5.1.jar:ccc2f3b00ec17b11401610ba68553544fc8fc517120e84439ac6eb86b875e18d',
+        'com.android.tools.analytics-library:tracker:26.5.1:tracker-26.5.1.jar:3a76984c0fe2e847ca7a8b35b4780ef0447a9d1666946cb8e60466318e0ab5ae',
+        'com.android.tools.build:aapt2-proto:0.4.0:aapt2-proto-0.4.0.jar:fac0435e08898f89eeeb9ca236bea707155ff816c12205ced285ad53604133ca',
+        'com.android.tools.build:apksig:3.5.1:apksig-3.5.1.jar:1fd33e7f009a2a0da766cfeec4211a09f548034b015c289a66d75dd8a9302f4a',
+        'com.android.tools.build:apkzlib:3.5.1:apkzlib-3.5.1.jar:9f330167cbe973b7db407692f74f4f6453b7ffa5f2048934b06280c2ceee60fa',
+        'com.android.tools.build:builder-model:3.5.1:builder-model-3.5.1.jar:39ea3c82b76b6e0c9f9fa88d93e0edc1dd4a0f1dfae0ef6fbf2d451da47e5450',
+        'com.android.tools.build:builder-test-api:3.5.1:builder-test-api-3.5.1.jar:a1b59305584cbcaa078fdc9cfb80871012755b822dd32e8da19add6f7bbcb762',
+        'com.android.tools.build:builder:3.5.1:builder-3.5.1.jar:e3a8d382434c5f60990730c4719fc814e85a898a33a1e96c1df8d627d3c6eea6',
+        'com.android.tools.build:gradle-api:3.5.1:gradle-api-3.5.1.jar:be9b41859bace11998f66b04ed944f87e413f3ad6da3c4665587699da125addc',
+        'com.android.tools.build:manifest-merger:26.5.1:manifest-merger-26.5.1.jar:dcad9ecb967251f4d750f55a4204a2b400e8fbfe5cb930a1d0d5dbe10ae8bdfc',
+        'com.android.tools.ddms:ddmlib:26.5.1:ddmlib-26.5.1.jar:b081aef2a4ed3f4d47cae4cdb128469735f25a114e026d37123bf9ffdec742a8',
+        'com.android.tools.external.com-intellij:intellij-core:26.5.1:intellij-core-26.5.1.jar:20eced30adc124805bd93488d9cd9d3e33e6bf7b48e9fe5a703d4983f894d450',
+        'com.android.tools.external.com-intellij:kotlin-compiler:26.5.1:kotlin-compiler-26.5.1.jar:5aed762dd54875b77ae7018d97c05756ff0c5b9fd02ec595dd396ccd14cc22cb',
+        'com.android.tools.external.org-jetbrains:uast:26.5.1:uast-26.5.1.jar:4bc8653d6c0943f40fee963a149e36c6baa45683d2530968a13f5007e3c40740',
+        'com.android.tools.layoutlib:layoutlib-api:26.5.1:layoutlib-api-26.5.1.jar:88732f11396c427273e515d23042e35633f4fe4295528a99b866aa2adf0efd9c',
+        'com.android.tools.lint:lint-api:26.5.1:lint-api-26.5.1.jar:ec33fcd72bfaf70dd841e03fbfd93f109c2e575aec146067c606689c3972f0de',
+        'com.android.tools.lint:lint-checks:26.5.1:lint-checks-26.5.1.jar:a1b9607d484aaae7a71dcecdc76f8003d8239af226c776894a2cf63f9e6c60d7',
+        'com.android.tools.lint:lint-gradle-api:26.5.1:lint-gradle-api-26.5.1.jar:82453fd98a8394cc84ed995c04d2cd744abd1d6589403427ba7eef53115406f3',
+        'com.android.tools.lint:lint-gradle:26.5.1:lint-gradle-26.5.1.jar:59465b56cf7db77c656d5f8195d721c3d48b6bdd0502d774de335bfe4baff00b',
+        'com.android.tools.lint:lint:26.5.1:lint-26.5.1.jar:336e4b04ec6f8b0f25879131b7a7862d77df83a1879ee5b71be26128755f8e2e',
+        'com.android.tools:annotations:26.5.1:annotations-26.5.1.jar:2c43c82f8c59d8f7a61e3239e1a2dc9f69dc342ec09af9b7c9f69b25337c0b6e',
+        'com.android.tools:common:26.5.1:common-26.5.1.jar:eccfa54486ed54c4e3123cc42195d023bd0dd21bcd2f0e4868e8c6fc70f8ef6b',
+        'com.android.tools:dvlib:26.5.1:dvlib-26.5.1.jar:46f93ad498b4756e7d867d2fe38c38890a80e7407a4ae459e4a8c8d5c5aeacfe',
+        'com.android.tools:repository:26.5.1:repository-26.5.1.jar:2b3ee791aa4c3e8ce60498c161a27ca7228816fc630eed4d9f25f2f36a106dce',
+        'com.android.tools:sdk-common:26.5.1:sdk-common-26.5.1.jar:365f749676c3574676fd465177c8a492f340816db2b520d6ed114d3b6e77bea7',
+        'com.android.tools:sdklib:26.5.1:sdklib-26.5.1.jar:007da104afb27c8c682a1628023fe9ec438249c8d15ef0fd6624c5bb8e23b696',
+        'com.google.code.findbugs:jsr305:3.0.2:jsr305-3.0.2.jar:766ad2a0783f2687962c8ad74ceecc38a28b9f72a2d085ee438b7813e928d0c7',
+        'com.google.code.gson:gson:2.8.5:gson-2.8.5.jar:233a0149fc365c9f6edbd683cfe266b19bdc773be98eabdaf6b3c924b48e7d81',
+        'com.google.dagger:dagger-compiler:2.24:dagger-compiler-2.24.jar:3c5afb955fb188da485cb2c048eff37dce0e1530b9780a0f2f7187d16d1ccc1f',
+        'com.google.dagger:dagger-producers:2.24:dagger-producers-2.24.jar:f10f45b95191954d5d6b043fca9e62fb621d21bf70634b8f8476c7988b504c3a',
+        'com.google.dagger:dagger-spi:2.24:dagger-spi-2.24.jar:c038445d14dbcb4054e61bf49e05009edf26fce4fdc7ec1a9db544784f68e718',
+        'com.google.dagger:dagger:2.24:dagger-2.24.jar:550a6e46a6dfcdf1d764887b6090cea94f783327e50e5c73754f18facfc70b64',
+        'com.google.errorprone:error_prone_annotations:2.2.0:error_prone_annotations-2.2.0.jar:6ebd22ca1b9d8ec06d41de8d64e0596981d9607b42035f9ed374f9de271a481a',
+        'com.google.errorprone:javac-shaded:9-dev-r4023-3:javac-shaded-9-dev-r4023-3.jar:65bfccf60986c47fbc17c9ebab0be626afc41741e0a6ec7109e0768817a36f30',
+        'com.google.googlejavaformat:google-java-format:1.5:google-java-format-1.5.jar:aa19ad7850fb85178aa22f2fddb163b84d6ce4d0035872f30d4408195ca1144e',
+        'com.google.guava:failureaccess:1.0.1:failureaccess-1.0.1.jar:a171ee4c734dd2da837e4b16be9df4661afab72a41adaf31eb84dfdaf936ca26',
+        'com.google.guava:guava:27.0.1-jre:guava-27.0.1-jre.jar:e1c814fd04492a27c38e0317eabeaa1b3e950ec8010239e400fe90ad6c9107b4',
+        'com.google.guava:guava:27.1-jre:guava-27.1-jre.jar:4a5aa70cc968a4d137e599ad37553e5cfeed2265e8c193476d7119036c536fe7',
+        'com.google.guava:listenablefuture:9999.0-empty-to-avoid-conflict-with-guava:listenablefuture-9999.0-empty-to-avoid-conflict-with-guava.jar:b372a037d4230aa57fbeffdef30fd6123f9c0c2db85d0aced00c91b974f33f99',
+        'com.google.j2objc:j2objc-annotations:1.1:j2objc-annotations-1.1.jar:2994a7eb78f2710bd3d3bfb639b2c94e219cedac0d4d084d516e78c16dddecf6',
+        'com.google.jimfs:jimfs:1.1:jimfs-1.1.jar:c4828e28d7c0a930af9387510b3bada7daa5c04d7c25a75c7b8b081f1c257ddd',
+        'com.google.protobuf:protobuf-java:3.4.0:protobuf-java-3.4.0.jar:dce7e66b32456a1b1198da0caff3a8acb71548658391e798c79369241e6490a4',
+        'com.googlecode.json-simple:json-simple:1.1:json-simple-1.1.jar:2d9484f4c649f708f47f9a479465fc729770ee65617dca3011836602264f6439',
+        'com.squareup:javapoet:1.11.1:javapoet-1.11.1.jar:9cbf2107be499ec6e95afd36b58e3ca122a24166cdd375732e51267d64058e90',
+        'com.squareup:javawriter:2.5.0:javawriter-2.5.0.jar:fcfb09fb0ea0aa97d3cfe7ea792398081348e468f126b3603cb3803f240197f0',
+        'com.sun.activation:javax.activation:1.2.0:javax.activation-1.2.0.jar:993302b16cd7056f21e779cc577d175a810bb4900ef73cd8fbf2b50f928ba9ce',
+        'com.sun.istack:istack-commons-runtime:2.21:istack-commons-runtime-2.21.jar:c33e67a0807095f02a0e2da139412dd7c4f9cc1a4c054b3e434f96831ba950f4',
+        'com.sun.xml.fastinfoset:FastInfoset:1.2.13:FastInfoset-1.2.13.jar:27a77db909f3c2833c0b1a37c55af1db06045118ad2eed96ce567b6632bce038',
+        'commons-codec:commons-codec:1.10:commons-codec-1.10.jar:4241dfa94e711d435f29a4604a3e2de5c4aa3c165e23bd066be6fc1fc4309569',
+        'commons-logging:commons-logging:1.2:commons-logging-1.2.jar:daddea1ea0be0f56978ab3006b8ac92834afeefbd9b7e4e6316fca57df0fa636',
+        'it.unimi.dsi:fastutil:7.2.0:fastutil-7.2.0.jar:74fa208043740642f7e6eb09faba15965218ad2f50ce3020efb100136e4b591c',
+        'javax.annotation:jsr250-api:1.0:jsr250-api-1.0.jar:a1a922d0d9b6d183ed3800dfac01d1e1eb159f0e8c6f94736931c1def54a941f',
+        'javax.inject:javax.inject:1:javax.inject-1.jar:91c77044a50c481636c32d916fd89c9118a72195390452c81065080f957de7ff',
+        'javax.xml.bind:jaxb-api:2.2.12-b140109.1041:jaxb-api-2.2.12-b140109.1041.jar:b5e60cd8b7b5ff01ce4a74c5dd008f4fbd14ced3495d0b47b85cfedc182211f2',
+        'junit:junit:4.12:junit-4.12.jar:59721f0805e223d84b90677887d9ff567dc534d7c502ca903c0c2b17f05c116a',
+        'net.ltgt.gradle.incap:incap:0.2:incap-0.2.jar:b625b9806b0f1e4bc7a2e3457119488de3cd57ea20feedd513db070a573a4ffd',
+        'net.sf.jopt-simple:jopt-simple:4.9:jopt-simple-4.9.jar:26c5856e954b5f864db76f13b86919b59c6eecf9fd930b96baa8884626baf2f5',
+        'net.sf.kxml:kxml2:2.3.0:kxml2-2.3.0.jar:f264dd9f79a1fde10ce5ecc53221eff24be4c9331c830b7d52f2f08a7b633de2',
+        'org.apache.ant:ant-launcher:1.9.4:ant-launcher-1.9.4.jar:7bccea20b41801ca17bcbc909a78c835d0f443f12d639c77bd6ae3d05861608d',
+        'org.apache.ant:ant:1.9.4:ant-1.9.4.jar:649ae0730251de07b8913f49286d46bba7b92d47c5f332610aa426c4f02161d8',
+        'org.apache.commons:commons-compress:1.12:commons-compress-1.12.jar:2c1542faf343185b7cab9c3d55c8ae5471d6d095d3887a4adefdbdf2984dc0b6',
+        'org.apache.httpcomponents:httpclient:4.5.6:httpclient-4.5.6.jar:c03f813195e7a80e3608d0ddd8da80b21696a4c92a6a2298865bf149071551c7',
+        'org.apache.httpcomponents:httpcore:4.4.10:httpcore-4.4.10.jar:78ba1096561957db1b55200a159b648876430342d15d461277e62360da19f6fd',
+        'org.apache.httpcomponents:httpmime:4.5.6:httpmime-4.5.6.jar:0b2b1102c18d3c7e05a77214b9b7501a6f6056174ae5604e0e256776eda7553e',
+        'org.beanshell:bsh:1.3.0:bsh-1.3.0.jar:9b04edc75d19db54f1b4e8b5355e9364384c6cf71eb0a1b9724c159d779879f8',
+        'org.bouncycastle:bcpkix-jdk15on:1.56:bcpkix-jdk15on-1.56.jar:7043dee4e9e7175e93e0b36f45b1ec1ecb893c5f755667e8b916eb8dd201c6ca',
+        'org.bouncycastle:bcprov-jdk15on:1.56:bcprov-jdk15on-1.56.jar:963e1ee14f808ffb99897d848ddcdb28fa91ddda867eb18d303e82728f878349',
+        'org.briarproject:obfs4proxy-android:0.0.11-2:obfs4proxy-android-0.0.11-2.zip:57e55cbe87aa2aac210fdbb6cd8cdeafe15f825406a08ebf77a8b787aa2c6a8a',
+        'org.briarproject:tor-android:0.3.5.9:tor-android-0.3.5.9.zip:853b0440feccd6904bd03e6b2de53a62ebcde1d58068beeadc447a7dff950bc8',
+        'org.checkerframework:checker-compat-qual:2.5.3:checker-compat-qual-2.5.3.jar:d76b9afea61c7c082908023f0cbc1427fab9abd2df915c8b8a3e7a509bccbc6d',
+        'org.checkerframework:checker-qual:2.5.2:checker-qual-2.5.2.jar:64b02691c8b9d4e7700f8ee2e742dce7ea2c6e81e662b7522c9ee3bf568c040a',
+        'org.codehaus.groovy:groovy-all:2.4.15:groovy-all-2.4.15.jar:51d6c4e71782e85674239189499854359d380fb75e1a703756e3aaa5b98a5af0',
+        'org.codehaus.mojo:animal-sniffer-annotations:1.17:animal-sniffer-annotations-1.17.jar:92654f493ecfec52082e76354f0ebf87648dc3d5cec2e3c3cdb947c016747a53',
+        'org.glassfish.jaxb:jaxb-core:2.2.11:jaxb-core-2.2.11.jar:37bcaee8ebb04362c8352a5bf6221b86967ecdab5164c696b10b9a2bb587b2aa',
+        'org.glassfish.jaxb:jaxb-runtime:2.2.11:jaxb-runtime-2.2.11.jar:a874f2351cfba8e2946be3002d10c18a6da8f21b52ba2acf52f2b85d5520ed70',
+        'org.glassfish.jaxb:txw2:2.2.11:txw2-2.2.11.jar:272a3ccad45a4511351920cd2a8633c53cab8d5220c7a92954da5526bb5eafea',
+        'org.hamcrest:hamcrest-core:1.3:hamcrest-core-1.3.jar:66fdef91e9739348df7a096aa384a5685f4e875584cce89386a7a47251c4d8e9',
+        'org.hamcrest:hamcrest-library:1.3:hamcrest-library-1.3.jar:711d64522f9ec410983bd310934296da134be4254a125080a0416ec178dfad1c',
+        'org.jetbrains.kotlin:kotlin-reflect:1.3.50:kotlin-reflect-1.3.50.jar:64583199ea5a54aefd1bd1595288925f784226ee562d1dd279011c6075b3d7a4',
+        'org.jetbrains.kotlin:kotlin-stdlib-common:1.3.50:kotlin-stdlib-common-1.3.50.jar:8ce678e88e4ba018b66dacecf952471e4d7dfee156a8a819760a5a5ff29d323c',
+        'org.jetbrains.kotlin:kotlin-stdlib-jdk7:1.3.50:kotlin-stdlib-jdk7-1.3.50.jar:9a026639e76212f8d57b86d55b075394c2e009f1979110751d34c05c5f75d57b',
+        'org.jetbrains.kotlin:kotlin-stdlib-jdk8:1.3.50:kotlin-stdlib-jdk8-1.3.50.jar:1b351fb6e09c14b55525c74c1f4cf48942eae43c348b7bc764a5e6e423d4da0c',
+        'org.jetbrains.kotlin:kotlin-stdlib:1.3.50:kotlin-stdlib-1.3.50.jar:e6f05746ee0366d0b52825a090fac474dcf44082c9083bbb205bd16976488d6c',
+        'org.jetbrains.trove4j:trove4j:20160824:trove4j-20160824.jar:1917871c8deb468307a584680c87a44572f5a8b0b98c6d397fc0f5f86596dbe7',
+        'org.jetbrains:annotations:13.0:annotations-13.0.jar:ace2a10dc8e2d5fd34925ecac03e4988b2c0f851650c94b8cef49ba1bd111478',
+        'org.jmock:jmock-junit4:2.8.2:jmock-junit4-2.8.2.jar:f7ee4df4f7bd7b7f1cafad3b99eb74d579f109d5992ff625347352edb55e674c',
+        'org.jmock:jmock-legacy:2.8.2:jmock-legacy-2.8.2.jar:f2b985a5c08a9edb7f37612330c058809da3f6a6d63ce792426ebf8ff0d6d31b',
+        'org.jmock:jmock-testjar:2.8.2:jmock-testjar-2.8.2.jar:8900860f72c474e027cf97fe78dcbf154a1aa7fc62b6845c5fb4e4f3c7bc8760',
+        'org.jmock:jmock:2.8.2:jmock-2.8.2.jar:6c73cb4a2e6dbfb61fd99c9a768539c170ab6568e57846bd60dbf19596b65b16',
+        'org.jvnet.staxex:stax-ex:1.7.7:stax-ex-1.7.7.jar:a31ff7d77163c0deb09e7fee59ad35ae44c2cee2cc8552a116ccd1583d813fb4',
+        'org.objenesis:objenesis:2.1:objenesis-2.1.jar:c74330cc6b806c804fd37e74487b4fe5d7c2750c5e15fbc6efa13bdee1bdef80',
+        'org.ow2.asm:asm-analysis:6.0:asm-analysis-6.0.jar:2f1a6387219c3a6cc4856481f221b03bd9f2408a326d416af09af5d6f608c1f4',
+        'org.ow2.asm:asm-commons:6.0:asm-commons-6.0.jar:f1bce5c648a96a017bdcd01fe5d59af9845297fd7b79b81c015a6fbbd9719abf',
+        'org.ow2.asm:asm-tree:6.0:asm-tree-6.0.jar:887998fb69727c8759e4d253f856822801e33f9fd4caa566b3ac58ee92106215',
+        'org.ow2.asm:asm-util:6.0:asm-util-6.0.jar:356afebdb0f870175262e5188f8709a3b17aa2a5a6a4b0340b04d4b449bca5f6',
+        'org.ow2.asm:asm:5.0.4:asm-5.0.4.jar:896618ed8ae62702521a78bc7be42b7c491a08e6920a15f89a3ecdec31e9a220',
+        'org.ow2.asm:asm:6.0:asm-6.0.jar:dd8971c74a4e697899a8e95caae4ea8760ea6c486dc6b97b1795e75760420461',
+    ]
+}

bramble-api/build.gradle

@@ -0,0 +1,31 @@
+apply plugin: 'java-library'
+sourceCompatibility = 1.8
+targetCompatibility = 1.8
+
+apply plugin: 'ru.vyarus.animalsniffer'
+apply plugin: 'witness'
+apply from: 'witness.gradle'
+
+dependencies {
+	implementation "com.google.dagger:dagger:2.24"
+	implementation 'com.google.code.findbugs:jsr305:3.0.2'
+
+	testImplementation 'junit:junit:4.12'
+	testImplementation "org.jmock:jmock:2.8.2"
+	testImplementation "org.jmock:jmock-junit4:2.8.2"
+	testImplementation "org.jmock:jmock-legacy:2.8.2"
+
+	signature 'org.codehaus.mojo.signature:java16:1.1@signature'
+}
+
+// needed to make test output available to bramble-core and briar-core
+configurations {
+	testOutput.extendsFrom(testCompile)
+}
+task jarTest(type: Jar, dependsOn: testClasses) {
+	from sourceSets.test.output
+	classifier = 'test'
+}
+artifacts {
+	testOutput jarTest
+}

bramble-api/src/main/java/org/briarproject/bramble/api/Bytes.java

@@ -0,0 +1,63 @@
+package org.briarproject.bramble.api;
+
+import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
+import org.briarproject.bramble.util.StringUtils;
+
+import java.util.Arrays;
+
+import javax.annotation.Nullable;
+import javax.annotation.concurrent.ThreadSafe;
+
+/**
+ * A wrapper around a byte array, to allow it to be stored in maps etc.
+ */
+@ThreadSafe
+@NotNullByDefault
+public class Bytes implements Comparable<Bytes> {
+
+	private final byte[] bytes;
+
+	private int hashCode = -1;
+
+	public Bytes(byte[] bytes) {
+		this.bytes = bytes;
+	}
+
+	public byte[] getBytes() {
+		return bytes;
+	}
+
+	@Override
+	public int hashCode() {
+		// Thread-safe because if two or more threads check and update the
+		// value, they'll calculate the same value
+		if (hashCode == -1) hashCode = Arrays.hashCode(bytes);
+		return hashCode;
+	}
+
+	@Override
+	public boolean equals(@Nullable Object o) {
+		return o instanceof Bytes && Arrays.equals(bytes, ((Bytes) o).bytes);
+	}
+
+	@Override
+	public int compareTo(Bytes other) {
+		return compare(bytes, other.bytes);
+	}
+
+	@Override
+	public String toString() {
+		return getClass().getSimpleName() +
+				"(" + StringUtils.toHexString(getBytes()) + ")";
+	}
+
+	public static int compare(byte[] a, byte[] b) {
+		int length = Math.min(a.length, b.length);
+		for (int i = 0; i < length; i++) {
+			int aUnsigned = a[i] & 0xFF, bUnsigned = b[i] & 0xFF;
+			if (aUnsigned < bUnsigned) return -1;
+			if (aUnsigned > bUnsigned) return 1;
+		}
+		return a.length - b.length;
+	}
+}

bramble-api/src/main/java/org/briarproject/bramble/api/FeatureFlags.java

@@ -0,0 +1,9 @@
+package org.briarproject.bramble.api;
+
+/**
+ * Interface for specifying which features are enabled in a build.
+ */
+public interface FeatureFlags {
+
+	boolean shouldEnableImageAttachments();
+}

bramble-api/src/main/java/org/briarproject/bramble/api/FormatException.java

@@ -0,0 +1,9 @@
+package org.briarproject.bramble.api;
+
+import java.io.IOException;
+
+/**
+ * An exception that indicates an unrecoverable formatting error.
+ */
+public class FormatException extends IOException {
+}

bramble-api/src/main/java/org/briarproject/bramble/api/Multiset.java

@@ -0,0 +1,101 @@
+package org.briarproject.bramble.api;
+
+import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
+
+import java.util.Collections;
+import java.util.HashMap;
+import java.util.Map;
+import java.util.NoSuchElementException;
+import java.util.Set;
+
+import javax.annotation.concurrent.NotThreadSafe;
+
+@NotThreadSafe
+@NotNullByDefault
+public class Multiset<T> {
+
+	private final Map<T, Integer> map = new HashMap<>();
+
+	private int total = 0;
+
+	/**
+	 * Returns how many items the multiset contains in total.
+	 */
+	public int getTotal() {
+		return total;
+	}
+
+	/**
+	 * Returns how many unique items the multiset contains.
+	 */
+	public int getUnique() {
+		return map.size();
+	}
+
+	/**
+	 * Returns how many of the given item the multiset contains.
+	 */
+	public int getCount(T t) {
+		Integer count = map.get(t);
+		return count == null ? 0 : count;
+	}
+
+	/**
+	 * Adds the given item to the multiset and returns how many of the item
+	 * the multiset now contains.
+	 */
+	public int add(T t) {
+		Integer count = map.get(t);
+		if (count == null) count = 0;
+		map.put(t, count + 1);
+		total++;
+		return count + 1;
+	}
+
+	/**
+	 * Removes the given item from the multiset and returns how many of the
+	 * item the multiset now contains.
+	 * @throws NoSuchElementException if the item is not in the multiset.
+	 */
+	public int remove(T t) {
+		Integer count = map.get(t);
+		if (count == null) throw new NoSuchElementException();
+		if (count == 1) map.remove(t);
+		else map.put(t, count - 1);
+		total--;
+		return count - 1;
+	}
+
+	/**
+	 * Removes all occurrences of the given item from the multiset.
+	 */
+	public int removeAll(T t) {
+		Integer count = map.remove(t);
+		if (count == null) return 0;
+		total -= count;
+		return count;
+	}
+
+	/**
+	 * Returns true if the multiset contains any occurrences of the given item.
+	 */
+	public boolean contains(T t) {
+		return map.containsKey(t);
+	}
+
+	/**
+	 * Removes all items from the multiset.
+	 */
+	public void clear() {
+		map.clear();
+		total = 0;
+	}
+
+	/**
+	 * Returns the set of unique items the multiset contains. The returned set
+	 * is unmodifiable.
+	 */
+	public Set<T> keySet() {
+		return Collections.unmodifiableSet(map.keySet());
+	}
+}

bramble-api/src/main/java/org/briarproject/bramble/api/Nameable.java

@@ -0,0 +1,10 @@
+package org.briarproject.bramble.api;
+
+import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
+
+@NotNullByDefault
+public interface Nameable {
+
+	String getName();
+
+}

bramble-api/src/main/java/org/briarproject/bramble/api/Pair.java

@@ -0,0 +1,26 @@
+package org.briarproject.bramble.api;
+
+import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
+
+import javax.annotation.concurrent.Immutable;
+
+@Immutable
+@NotNullByDefault
+public class Pair<A, B> {
+
+	private final A first;
+	private final B second;
+
+	public Pair(A first, B second) {
+		this.first = first;
+		this.second = second;
+	}
+
+	public A getFirst() {
+		return first;
+	}
+
+	public B getSecond() {
+		return second;
+	}
+}

bramble-api/src/main/java/org/briarproject/bramble/api/Predicate.java

@@ -0,0 +1,9 @@
+package org.briarproject.bramble.api;
+
+import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
+
+@NotNullByDefault
+public interface Predicate<T> {
+
+	boolean test(T t);
+}

bramble-api/src/main/java/org/briarproject/bramble/api/StringMap.java

@@ -0,0 +1,55 @@
+package org.briarproject.bramble.api;
+
+import java.util.Hashtable;
+import java.util.Map;
+
+public abstract class StringMap extends Hashtable<String, String> {
+
+	protected StringMap(Map<String, String> m) {
+		super(m);
+	}
+
+	protected StringMap() {
+		super();
+	}
+
+	public boolean getBoolean(String key, boolean defaultValue) {
+		String s = get(key);
+		if (s == null) return defaultValue;
+		if ("true".equals(s)) return true;
+		if ("false".equals(s)) return false;
+		return defaultValue;
+	}
+
+	public void putBoolean(String key, boolean value) {
+		put(key, String.valueOf(value));
+	}
+
+	public int getInt(String key, int defaultValue) {
+		String s = get(key);
+		if (s == null) return defaultValue;
+		try {
+			return Integer.valueOf(s);
+		} catch (NumberFormatException e) {
+			return defaultValue;
+		}
+	}
+
+	public void putInt(String key, int value) {
+		put(key, String.valueOf(value));
+	}
+
+	public long getLong(String key, long defaultValue) {
+		String s = get(key);
+		if (s == null) return defaultValue;
+		try {
+			return Long.valueOf(s);
+		} catch (NumberFormatException e) {
+			return defaultValue;
+		}
+	}
+
+	public void putLong(String key, long value) {
+		put(key, String.valueOf(value));
+	}
+}

bramble-api/src/main/java/org/briarproject/bramble/api/UniqueId.java

@@ -0,0 +1,20 @@
+package org.briarproject.bramble.api;
+
+import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
+
+import javax.annotation.concurrent.ThreadSafe;
+
+@ThreadSafe
+@NotNullByDefault
+public abstract class UniqueId extends Bytes {
+
+	/**
+	 * The length of a unique identifier in bytes.
+	 */
+	public static final int LENGTH = 32;
+
+	protected UniqueId(byte[] id) {
+		super(id);
+		if (id.length != LENGTH) throw new IllegalArgumentException();
+	}
+}

bramble-api/src/main/java/org/briarproject/bramble/api/UnsupportedVersionException.java

@@ -0,0 +1,18 @@
+package org.briarproject.bramble.api;
+
+/**
+ * Thrown when data being parsed uses a protocol or format version that is not
+ * supported.
+ */
+public class UnsupportedVersionException extends FormatException {
+
+	private final boolean tooOld;
+
+	public UnsupportedVersionException(boolean tooOld) {
+		this.tooOld = tooOld;
+	}
+
+	public boolean isTooOld() {
+		return tooOld;
+	}
+}

bramble-api/src/main/java/org/briarproject/bramble/api/account/AccountManager.java

@@ -0,0 +1,70 @@
+package org.briarproject.bramble.api.account;
+
+import org.briarproject.bramble.api.crypto.SecretKey;
+import org.briarproject.bramble.api.identity.IdentityManager;
+import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
+
+import javax.annotation.Nullable;
+
+@NotNullByDefault
+public interface AccountManager {
+
+	/**
+	 * Returns true if the manager has the database key. This will be false
+	 * before {@link #createAccount(String, String)} or {@link #signIn(String)}
+	 * has been called, and true after {@link #createAccount(String, String)}
+	 * or {@link #signIn(String)} has returned true, until the process exits.
+	 */
+	boolean hasDatabaseKey();
+
+	/**
+	 * Returns the database key if the manager has it. This will be null
+	 * before {@link #createAccount(String, String)} or {@link #signIn(String)}
+	 * has been called, and non-null after
+	 * {@link #createAccount(String, String)} or {@link #signIn(String)} has
+	 * returned true, until the process exits.
+	 */
+	@Nullable
+	SecretKey getDatabaseKey();
+
+	/**
+	 * Returns true if the encrypted database key can be loaded from disk, and
+	 * the database directory exists and is a directory.
+	 */
+	boolean accountExists();
+
+	/**
+	 * Creates an identity with the given name and registers it with the
+	 * {@link IdentityManager}. Creates a database key, encrypts it with the
+	 * given password and stores it on disk.
+	 * <p/>
+	 * This method does not create the database directory, so
+	 * {@link #accountExists()} will continue to return false until the
+	 * database directory is created.
+	 */
+	boolean createAccount(String name, String password);
+
+	/**
+	 * Deletes all account state from disk. {@link #accountExists()} will
+	 * return false after this method returns.
+	 */
+	void deleteAccount();
+
+	/**
+	 * Loads the encrypted database key from disk and decrypts it with the
+	 * given password.
+	 *
+	 * @return true if the database key was successfully loaded and decrypted.
+	 */
+	boolean signIn(String password);
+
+	/**
+	 * Loads the encrypted database key from disk, decrypts it with the old
+	 * password, encrypts it with the new password, and stores it on disk,
+	 * replacing the old key.
+	 *
+	 * @return true if the database key was successfully loaded, re-encrypted
+	 * and stored.
+	 */
+	boolean changePassword(String oldPassword, String newPassword);
+}

bramble-api/src/main/java/org/briarproject/bramble/api/battery/BatteryManager.java

@@ -0,0 +1,6 @@
+package org.briarproject.bramble.api.battery;
+
+public interface BatteryManager {
+
+	boolean isCharging();
+}

bramble-api/src/main/java/org/briarproject/bramble/api/battery/event/BatteryEvent.java

@@ -0,0 +1,19 @@
+package org.briarproject.bramble.api.battery.event;
+
+import org.briarproject.bramble.api.event.Event;
+
+/**
+ * An event that is broadcast when the device starts or stops charging.
+ */
+public class BatteryEvent extends Event {
+
+	private final boolean charging;
+
+	public BatteryEvent(boolean charging) {
+		this.charging = charging;
+	}
+
+	public boolean isCharging() {
+		return charging;
+	}
+}

bramble-api/src/main/java/org/briarproject/bramble/api/client/BdfIncomingMessageHook.java

@@ -0,0 +1,65 @@
+package org.briarproject.bramble.api.client;
+
+import org.briarproject.bramble.api.FormatException;
+import org.briarproject.bramble.api.data.BdfDictionary;
+import org.briarproject.bramble.api.data.BdfList;
+import org.briarproject.bramble.api.data.MetadataParser;
+import org.briarproject.bramble.api.db.DatabaseComponent;
+import org.briarproject.bramble.api.db.DbException;
+import org.briarproject.bramble.api.db.Metadata;
+import org.briarproject.bramble.api.db.Transaction;
+import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
+import org.briarproject.bramble.api.sync.InvalidMessageException;
+import org.briarproject.bramble.api.sync.Message;
+import org.briarproject.bramble.api.sync.validation.IncomingMessageHook;
+
+import javax.annotation.concurrent.Immutable;
+
+@Immutable
+@NotNullByDefault
+public abstract class BdfIncomingMessageHook implements IncomingMessageHook {
+
+	protected final DatabaseComponent db;
+	protected final ClientHelper clientHelper;
+	protected final MetadataParser metadataParser;
+
+	protected BdfIncomingMessageHook(DatabaseComponent db,
+			ClientHelper clientHelper, MetadataParser metadataParser) {
+		this.db = db;
+		this.clientHelper = clientHelper;
+		this.metadataParser = metadataParser;
+	}
+
+	/**
+	 * Called once for each incoming message that passes validation.
+	 *
+	 * @param txn A read-write transaction
+	 * @return Whether or not this message should be shared
+	 * @throws DbException Should only be used for real database errors.
+	 * If this is thrown, delivery will be attempted again at next startup,
+	 * whereas if a FormatException is thrown, the message will be permanently
+	 * invalidated.
+	 * @throws FormatException Use this for any non-database error
+	 * that occurs while handling remotely created data.
+	 * This includes errors that occur while handling locally created data
+	 * in a context controlled by remotely created data
+	 * (for example, parsing the metadata of a dependency
+	 * of an incoming message).
+	 * Never rethrow DbException as FormatException!
+	 */
+	protected abstract boolean incomingMessage(Transaction txn, Message m,
+			BdfList body, BdfDictionary meta) throws DbException,
+			FormatException;
+
+	@Override
+	public boolean incomingMessage(Transaction txn, Message m, Metadata meta)
+			throws DbException, InvalidMessageException {
+		try {
+			BdfList body = clientHelper.toList(m);
+			BdfDictionary metaDictionary = metadataParser.parse(meta);
+			return incomingMessage(txn, m, body, metaDictionary);
+		} catch (FormatException e) {
+			throw new InvalidMessageException(e);
+		}
+	}
+}

bramble-api/src/main/java/org/briarproject/bramble/api/client/BdfMessageContext.java

@@ -0,0 +1,36 @@
+package org.briarproject.bramble.api.client;
+
+import org.briarproject.bramble.api.data.BdfDictionary;
+import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
+import org.briarproject.bramble.api.sync.MessageId;
+
+import java.util.Collection;
+import java.util.Collections;
+
+import javax.annotation.concurrent.Immutable;
+
+@Immutable
+@NotNullByDefault
+public class BdfMessageContext {
+
+	private final BdfDictionary dictionary;
+	private final Collection<MessageId> dependencies;
+
+	public BdfMessageContext(BdfDictionary dictionary,
+			Collection<MessageId> dependencies) {
+		this.dictionary = dictionary;
+		this.dependencies = dependencies;
+	}
+
+	public BdfMessageContext(BdfDictionary dictionary) {
+		this(dictionary, Collections.emptyList());
+	}
+
+	public BdfDictionary getDictionary() {
+		return dictionary;
+	}
+
+	public Collection<MessageId> getDependencies() {
+		return dependencies;
+	}
+}

bramble-api/src/main/java/org/briarproject/bramble/api/client/BdfMessageValidator.java

@@ -0,0 +1,60 @@
+package org.briarproject.bramble.api.client;
+
+import org.briarproject.bramble.api.FormatException;
+import org.briarproject.bramble.api.data.BdfList;
+import org.briarproject.bramble.api.data.MetadataEncoder;
+import org.briarproject.bramble.api.db.Metadata;
+import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
+import org.briarproject.bramble.api.sync.Group;
+import org.briarproject.bramble.api.sync.InvalidMessageException;
+import org.briarproject.bramble.api.sync.Message;
+import org.briarproject.bramble.api.sync.MessageContext;
+import org.briarproject.bramble.api.sync.validation.MessageValidator;
+import org.briarproject.bramble.api.system.Clock;
+
+import java.util.logging.Logger;
+
+import javax.annotation.concurrent.Immutable;
+
+import static org.briarproject.bramble.api.transport.TransportConstants.MAX_CLOCK_DIFFERENCE;
+
+@Immutable
+@NotNullByDefault
+public abstract class BdfMessageValidator implements MessageValidator {
+
+	protected static final Logger LOG =
+			Logger.getLogger(BdfMessageValidator.class.getName());
+
+	protected final ClientHelper clientHelper;
+	protected final MetadataEncoder metadataEncoder;
+	protected final Clock clock;
+
+	protected BdfMessageValidator(ClientHelper clientHelper,
+			MetadataEncoder metadataEncoder, Clock clock) {
+		this.clientHelper = clientHelper;
+		this.metadataEncoder = metadataEncoder;
+		this.clock = clock;
+	}
+
+	protected abstract BdfMessageContext validateMessage(Message m, Group g,
+			BdfList body) throws InvalidMessageException, FormatException;
+
+	@Override
+	public MessageContext validateMessage(Message m, Group g)
+			throws InvalidMessageException {
+		// Reject the message if it's too far in the future
+		long now = clock.currentTimeMillis();
+		if (m.getTimestamp() - now > MAX_CLOCK_DIFFERENCE) {
+			throw new InvalidMessageException(
+					"Timestamp is too far in the future");
+		}
+		try {
+			BdfList bodyList = clientHelper.toList(m.getBody());
+			BdfMessageContext result = validateMessage(m, g, bodyList);
+			Metadata meta = metadataEncoder.encode(result.getDictionary());
+			return new MessageContext(meta, result.getDependencies());
+		} catch (FormatException e) {
+			throw new InvalidMessageException(e);
+		}
+	}
+}

bramble-api/src/main/java/org/briarproject/bramble/api/client/ClientHelper.java

@@ -0,0 +1,122 @@
+package org.briarproject.bramble.api.client;
+
+import org.briarproject.bramble.api.FormatException;
+import org.briarproject.bramble.api.crypto.PrivateKey;
+import org.briarproject.bramble.api.crypto.PublicKey;
+import org.briarproject.bramble.api.data.BdfDictionary;
+import org.briarproject.bramble.api.data.BdfList;
+import org.briarproject.bramble.api.db.DbException;
+import org.briarproject.bramble.api.db.Transaction;
+import org.briarproject.bramble.api.identity.Author;
+import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
+import org.briarproject.bramble.api.plugin.TransportId;
+import org.briarproject.bramble.api.properties.TransportProperties;
+import org.briarproject.bramble.api.sync.GroupId;
+import org.briarproject.bramble.api.sync.Message;
+import org.briarproject.bramble.api.sync.MessageId;
+
+import java.security.GeneralSecurityException;
+import java.util.Map;
+
+@NotNullByDefault
+public interface ClientHelper {
+
+	void addLocalMessage(Message m, BdfDictionary metadata, boolean shared)
+			throws DbException, FormatException;
+
+	void addLocalMessage(Transaction txn, Message m, BdfDictionary metadata,
+			boolean shared, boolean temporary)
+			throws DbException, FormatException;
+
+	Message createMessage(GroupId g, long timestamp, byte[] body);
+
+	Message createMessage(GroupId g, long timestamp, BdfList body)
+			throws FormatException;
+
+	Message createMessageForStoringMetadata(GroupId g);
+
+	Message getMessage(MessageId m) throws DbException;
+
+	Message getMessage(Transaction txn, MessageId m) throws DbException;
+
+	BdfList getMessageAsList(MessageId m) throws DbException, FormatException;
+
+	BdfList getMessageAsList(Transaction txn, MessageId m) throws DbException,
+			FormatException;
+
+	BdfDictionary getGroupMetadataAsDictionary(GroupId g) throws DbException,
+			FormatException;
+
+	BdfDictionary getGroupMetadataAsDictionary(Transaction txn, GroupId g)
+			throws DbException, FormatException;
+
+	BdfDictionary getMessageMetadataAsDictionary(MessageId m)
+			throws DbException,
+			FormatException;
+
+	BdfDictionary getMessageMetadataAsDictionary(Transaction txn, MessageId m)
+			throws DbException, FormatException;
+
+	Map<MessageId, BdfDictionary> getMessageMetadataAsDictionary(GroupId g)
+			throws DbException, FormatException;
+
+	Map<MessageId, BdfDictionary> getMessageMetadataAsDictionary(
+			Transaction txn, GroupId g) throws DbException, FormatException;
+
+	Map<MessageId, BdfDictionary> getMessageMetadataAsDictionary(GroupId g,
+			BdfDictionary query) throws DbException, FormatException;
+
+	Map<MessageId, BdfDictionary> getMessageMetadataAsDictionary(
+			Transaction txn, GroupId g, BdfDictionary query) throws DbException,
+			FormatException;
+
+	void mergeGroupMetadata(GroupId g, BdfDictionary metadata)
+			throws DbException, FormatException;
+
+	void mergeGroupMetadata(Transaction txn, GroupId g, BdfDictionary metadata)
+			throws DbException, FormatException;
+
+	void mergeMessageMetadata(MessageId m, BdfDictionary metadata)
+			throws DbException, FormatException;
+
+	void mergeMessageMetadata(Transaction txn, MessageId m,
+			BdfDictionary metadata) throws DbException, FormatException;
+
+	byte[] toByteArray(BdfDictionary dictionary) throws FormatException;
+
+	byte[] toByteArray(BdfList list) throws FormatException;
+
+	BdfDictionary toDictionary(byte[] b, int off, int len)
+			throws FormatException;
+
+	BdfDictionary toDictionary(TransportProperties transportProperties);
+
+	BdfDictionary toDictionary(Map<TransportId, TransportProperties> map);
+
+	BdfList toList(byte[] b, int off, int len) throws FormatException;
+
+	BdfList toList(byte[] b) throws FormatException;
+
+	BdfList toList(Message m) throws FormatException;
+
+	BdfList toList(Author a);
+
+	byte[] sign(String label, BdfList toSign, PrivateKey privateKey)
+			throws FormatException, GeneralSecurityException;
+
+	void verifySignature(byte[] signature, String label, BdfList signed,
+			PublicKey publicKey)
+			throws FormatException, GeneralSecurityException;
+
+	Author parseAndValidateAuthor(BdfList author) throws FormatException;
+
+	PublicKey parseAndValidateAgreementPublicKey(byte[] publicKeyBytes)
+			throws FormatException;
+
+	TransportProperties parseAndValidateTransportProperties(
+			BdfDictionary properties) throws FormatException;
+
+	Map<TransportId, TransportProperties> parseAndValidateTransportPropertiesMap(
+			BdfDictionary properties) throws FormatException;
+
+}

bramble-api/src/main/java/org/briarproject/bramble/api/client/ContactGroupFactory.java

@@ -0,0 +1,30 @@
+package org.briarproject.bramble.api.client;
+
+import org.briarproject.bramble.api.contact.Contact;
+import org.briarproject.bramble.api.identity.AuthorId;
+import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
+import org.briarproject.bramble.api.sync.ClientId;
+import org.briarproject.bramble.api.sync.Group;
+
+@NotNullByDefault
+public interface ContactGroupFactory {
+
+	/**
+	 * Creates a group that is not shared with any contacts.
+	 */
+	Group createLocalGroup(ClientId clientId, int majorVersion);
+
+	/**
+	 * Creates a group for the given client to share with the given contact.
+	 */
+	Group createContactGroup(ClientId clientId, int majorVersion,
+			Contact contact);
+
+	/**
+	 * Creates a group for the given client to share between the given authors
+	 * identified by their AuthorIds.
+	 */
+	Group createContactGroup(ClientId clientId, int majorVersion,
+			AuthorId authorId1, AuthorId authorId2);
+
+}

bramble-api/src/main/java/org/briarproject/bramble/api/contact/Contact.java

@@ -0,0 +1,78 @@
+package org.briarproject.bramble.api.contact;
+
+import org.briarproject.bramble.api.crypto.PublicKey;
+import org.briarproject.bramble.api.identity.Author;
+import org.briarproject.bramble.api.identity.AuthorId;
+import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
+
+import javax.annotation.Nullable;
+import javax.annotation.concurrent.Immutable;
+
+import static org.briarproject.bramble.api.identity.AuthorConstants.MAX_AUTHOR_NAME_LENGTH;
+import static org.briarproject.bramble.util.StringUtils.toUtf8;
+
+@Immutable
+@NotNullByDefault
+public class Contact {
+
+	private final ContactId id;
+	private final Author author;
+	private final AuthorId localAuthorId;
+	@Nullable
+	private final String alias;
+	@Nullable
+	private final PublicKey handshakePublicKey;
+	private final boolean verified;
+
+	public Contact(ContactId id, Author author, AuthorId localAuthorId,
+			@Nullable String alias, @Nullable PublicKey handshakePublicKey,
+			boolean verified) {
+		if (alias != null) {
+			int aliasLength = toUtf8(alias).length;
+			if (aliasLength == 0 || aliasLength > MAX_AUTHOR_NAME_LENGTH)
+				throw new IllegalArgumentException();
+		}
+		this.id = id;
+		this.author = author;
+		this.localAuthorId = localAuthorId;
+		this.alias = alias;
+		this.handshakePublicKey = handshakePublicKey;
+		this.verified = verified;
+	}
+
+	public ContactId getId() {
+		return id;
+	}
+
+	public Author getAuthor() {
+		return author;
+	}
+
+	public AuthorId getLocalAuthorId() {
+		return localAuthorId;
+	}
+
+	@Nullable
+	public String getAlias() {
+		return alias;
+	}
+
+	@Nullable
+	public PublicKey getHandshakePublicKey() {
+		return handshakePublicKey;
+	}
+
+	public boolean isVerified() {
+		return verified;
+	}
+
+	@Override
+	public int hashCode() {
+		return id.hashCode();
+	}
+
+	@Override
+	public boolean equals(Object o) {
+		return o instanceof Contact && id.equals(((Contact) o).id);
+	}
+}

bramble-api/src/main/java/org/briarproject/bramble/api/contact/ContactExchangeManager.java

@@ -0,0 +1,37 @@
+package org.briarproject.bramble.api.contact;
+
+import org.briarproject.bramble.api.crypto.SecretKey;
+import org.briarproject.bramble.api.db.ContactExistsException;
+import org.briarproject.bramble.api.db.DbException;
+import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
+import org.briarproject.bramble.api.plugin.duplex.DuplexTransportConnection;
+
+import java.io.IOException;
+
+@NotNullByDefault
+public interface ContactExchangeManager {
+
+	/**
+	 * Exchanges contact information with a remote peer and adds the peer
+	 * as a contact.
+	 *
+	 * @param alice Whether the local peer takes the role of Alice
+	 * @return The newly added contact
+	 * @throws ContactExistsException If the contact already exists
+	 */
+	Contact exchangeContacts(DuplexTransportConnection conn,
+			SecretKey masterKey, boolean alice, boolean verified)
+			throws IOException, DbException;
+
+	/**
+	 * Exchanges contact information with a remote peer and adds the peer
+	 * as a contact, replacing the given pending contact.
+	 *
+	 * @param alice Whether the local peer takes the role of Alice
+	 * @return The newly added contact
+	 * @throws ContactExistsException If the contact already exists
+	 */
+	Contact exchangeContacts(PendingContactId p, DuplexTransportConnection conn,
+			SecretKey masterKey, boolean alice, boolean verified)
+			throws IOException, DbException;
+}

bramble-api/src/main/java/org/briarproject/bramble/api/contact/ContactId.java

@@ -0,0 +1,35 @@
+package org.briarproject.bramble.api.contact;
+
+import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
+
+import javax.annotation.Nullable;
+import javax.annotation.concurrent.Immutable;
+
+/**
+ * Type-safe wrapper for an integer that uniquely identifies a contact within
+ * the scope of the local device.
+ */
+@Immutable
+@NotNullByDefault
+public class ContactId {
+
+	private final int id;
+
+	public ContactId(int id) {
+		this.id = id;
+	}
+
+	public int getInt() {
+		return id;
+	}
+
+	@Override
+	public int hashCode() {
+		return id;
+	}
+
+	@Override
+	public boolean equals(@Nullable Object o) {
+		return o instanceof ContactId && id == ((ContactId) o).id;
+	}
+}

bramble-api/src/main/java/org/briarproject/bramble/api/contact/ContactManager.java

@@ -0,0 +1,246 @@
+package org.briarproject.bramble.api.contact;
+
+import org.briarproject.bramble.api.FormatException;
+import org.briarproject.bramble.api.Pair;
+import org.briarproject.bramble.api.UnsupportedVersionException;
+import org.briarproject.bramble.api.crypto.SecretKey;
+import org.briarproject.bramble.api.db.ContactExistsException;
+import org.briarproject.bramble.api.db.DbException;
+import org.briarproject.bramble.api.db.NoSuchContactException;
+import org.briarproject.bramble.api.db.PendingContactExistsException;
+import org.briarproject.bramble.api.db.Transaction;
+import org.briarproject.bramble.api.identity.Author;
+import org.briarproject.bramble.api.identity.AuthorId;
+import org.briarproject.bramble.api.identity.AuthorInfo;
+import org.briarproject.bramble.api.lifecycle.LifecycleManager;
+import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
+
+import java.security.GeneralSecurityException;
+import java.util.Collection;
+
+import javax.annotation.Nullable;
+
+@NotNullByDefault
+public interface ContactManager {
+
+	/**
+	 * Registers a hook to be called whenever a contact is added or removed.
+	 * This method should be called before
+	 * {@link LifecycleManager#startServices(SecretKey)}.
+	 */
+	void registerContactHook(ContactHook hook);
+
+	/**
+	 * Stores a contact associated with the given local and remote pseudonyms,
+	 * derives and stores rotation mode transport keys for each transport, and
+	 * returns an ID for the contact.
+	 *
+	 * @param rootKey The root key for a set of rotation mode transport keys
+	 * @param timestamp The timestamp for deriving rotation mode transport
+	 * keys from the root key
+	 * @param alice True if the local party is Alice
+	 * @param verified True if the contact's identity has been verified, which
+	 * is true if the contact was added in person or false if the contact was
+	 * introduced or added remotely
+	 * @param active True if the rotation mode transport keys can be used for
+	 * outgoing streams
+	 */
+	ContactId addContact(Transaction txn, Author remote, AuthorId local,
+			SecretKey rootKey, long timestamp, boolean alice, boolean verified,
+			boolean active) throws DbException;
+
+	/**
+	 * Stores a contact associated with the given local and remote pseudonyms,
+	 * replacing the given pending contact, derives and stores handshake mode
+	 * and rotation mode transport keys for each transport, and returns an ID
+	 * for the contact.
+	 *
+	 * @param rootKey The root key for a set of rotation mode transport keys
+	 * @param timestamp The timestamp for deriving rotation mode transport
+	 * keys from the root key
+	 * @param alice True if the local party is Alice
+	 * @param verified True if the contact's identity has been verified, which
+	 * is true if the contact was added in person or false if the contact was
+	 * introduced or added remotely
+	 * @param active True if the rotation mode transport keys can be used for
+	 * outgoing streams
+	 * @throws GeneralSecurityException If the pending contact's handshake
+	 * public key is invalid
+	 */
+	ContactId addContact(Transaction txn, PendingContactId p, Author remote,
+			AuthorId local, SecretKey rootKey, long timestamp, boolean alice,
+			boolean verified, boolean active)
+			throws DbException, GeneralSecurityException;
+
+	/**
+	 * Stores a contact associated with the given local and remote pseudonyms
+	 * and returns an ID for the contact.
+	 *
+	 * @param verified True if the contact's identity has been verified, which
+	 * is true if the contact was added in person or false if the contact was
+	 * introduced or added remotely
+	 */
+	ContactId addContact(Transaction txn, Author remote, AuthorId local,
+			boolean verified) throws DbException;
+
+	/**
+	 * Stores a contact associated with the given local and remote pseudonyms,
+	 * derives and stores rotation mode transport keys for each transport, and
+	 * returns an ID for the contact.
+	 *
+	 * @param rootKey The root key for a set of rotation mode transport keys
+	 * @param timestamp The timestamp for deriving rotation mode transport
+	 * keys from the root key
+	 * @param alice True if the local party is Alice
+	 * @param verified True if the contact's identity has been verified, which
+	 * is true if the contact was added in person or false if the contact was
+	 * introduced or added remotely
+	 * @param active True if the rotation mode transport keys can be used for
+	 * outgoing streams
+	 */
+	ContactId addContact(Author remote, AuthorId local, SecretKey rootKey,
+			long timestamp, boolean alice, boolean verified, boolean active)
+			throws DbException;
+
+	/**
+	 * Returns the handshake link that needs to be sent to a contact we want
+	 * to add.
+	 */
+	String getHandshakeLink() throws DbException;
+
+	/**
+	 * Creates a {@link PendingContact} from the given handshake link and
+	 * alias, adds it to the database and returns it.
+	 *
+	 * @param link The handshake link received from the pending contact
+	 * @param alias The alias the user has given this pending contact
+	 * @throws UnsupportedVersionException If the link uses a format version
+	 * that is not supported
+	 * @throws FormatException If the link is invalid
+	 * @throws GeneralSecurityException If the pending contact's handshake
+	 * public key is invalid
+	 * @throws ContactExistsException If a contact with the same handshake
+	 * public key already exists
+	 * @throws PendingContactExistsException If a pending contact with the same
+	 * handshake public key already exists
+	 */
+	PendingContact addPendingContact(String link, String alias)
+			throws DbException, FormatException, GeneralSecurityException,
+			ContactExistsException, PendingContactExistsException;
+
+	/**
+	 * Returns the pending contact with the given ID.
+	 */
+	PendingContact getPendingContact(Transaction txn, PendingContactId p)
+			throws DbException;
+
+	/**
+	 * Returns a list of {@link PendingContact PendingContacts} and their
+	 * {@link PendingContactState states}.
+	 */
+	Collection<Pair<PendingContact, PendingContactState>> getPendingContacts()
+			throws DbException;
+
+	/**
+	 * Removes a {@link PendingContact}.
+	 */
+	void removePendingContact(PendingContactId p) throws DbException;
+
+	/**
+	 * Returns the contact with the given ID.
+	 */
+	Contact getContact(ContactId c) throws DbException;
+
+	/**
+	 * Returns the contact with the given ID.
+	 */
+	Contact getContact(Transaction txn, ContactId c) throws DbException;
+
+	/**
+	 * Returns the contact with the given {@code remoteAuthorId}
+	 * that belongs to the local pseudonym with the given {@code localAuthorId}.
+	 *
+	 * @throws NoSuchContactException If the contact is not in the database
+	 */
+	Contact getContact(AuthorId remoteAuthorId, AuthorId localAuthorId)
+			throws DbException;
+
+	/**
+	 * Returns the contact with the given {@code remoteAuthorId}
+	 * that belongs to the local pseudonym with the given {@code localAuthorId}.
+	 *
+	 * @throws NoSuchContactException If the contact is not in the database
+	 */
+	Contact getContact(Transaction txn, AuthorId remoteAuthorId,
+			AuthorId localAuthorId) throws DbException;
+
+	/**
+	 * Returns all contacts.
+	 */
+	Collection<Contact> getContacts() throws DbException;
+
+	/**
+	 * Removes a contact and all associated state.
+	 */
+	void removeContact(ContactId c) throws DbException;
+
+	/**
+	 * Removes a contact and all associated state.
+	 */
+	void removeContact(Transaction txn, ContactId c) throws DbException;
+
+	/**
+	 * Sets an alias for the contact or unsets it if {@code alias} is null.
+	 */
+	void setContactAlias(Transaction txn, ContactId c, @Nullable String alias)
+			throws DbException;
+
+	/**
+	 * Sets an alias for the contact or unsets it if {@code alias} is null.
+	 */
+	void setContactAlias(ContactId c, @Nullable String alias)
+			throws DbException;
+
+	/**
+	 * Returns true if a contact with this {@code remoteAuthorId} belongs to
+	 * the local pseudonym with this {@code localAuthorId}.
+	 */
+	boolean contactExists(Transaction txn, AuthorId remoteAuthorId,
+			AuthorId localAuthorId) throws DbException;
+
+	/**
+	 * Returns true if a contact with this {@code remoteAuthorId} belongs to
+	 * the local pseudonym with this {@code localAuthorId}.
+	 */
+	boolean contactExists(AuthorId remoteAuthorId, AuthorId localAuthorId)
+			throws DbException;
+
+	/**
+	 * Returns the {@link AuthorInfo} for the given author.
+	 */
+	AuthorInfo getAuthorInfo(AuthorId a) throws DbException;
+
+	/**
+	 * Returns the {@link AuthorInfo} for the given author.
+	 */
+	AuthorInfo getAuthorInfo(Transaction txn, AuthorId a) throws DbException;
+
+	interface ContactHook {
+
+		/**
+		 * Called when a contact is being added.
+		 *
+		 * @param txn A read-write transaction
+		 * @param c The contact that is being added
+		 */
+		void addingContact(Transaction txn, Contact c) throws DbException;
+
+		/**
+		 * Called when a contact is being removed
+		 *
+		 * @param txn A read-write transaction
+		 * @param c The contact that is being removed
+		 */
+		void removingContact(Transaction txn, Contact c) throws DbException;
+	}
+}

bramble-api/src/main/java/org/briarproject/bramble/api/contact/HandshakeLinkConstants.java

@@ -0,0 +1,34 @@
+package org.briarproject.bramble.api.contact;
+
+import java.util.regex.Pattern;
+
+public interface HandshakeLinkConstants {
+
+	/**
+	 * The current version of the handshake link format.
+	 */
+	int FORMAT_VERSION = 0;
+
+	/**
+	 * The length of a base32-encoded handshake link in bytes, excluding the
+	 * 'briar://' prefix.
+	 */
+	int BASE32_LINK_BYTES = 53;
+
+	/**
+	 * The length of a raw handshake link in bytes, before base32 encoding.
+	 */
+	int RAW_LINK_BYTES = 33;
+
+	/**
+	 * Regular expression for matching handshake links, including or excluding
+	 * the 'briar://' prefix.
+	 */
+	Pattern LINK_REGEX =
+			Pattern.compile("(briar://)?([a-z2-7]{" + BASE32_LINK_BYTES + "})");
+
+	/**
+	 * Label for hashing handshake public keys to calculate their identifiers.
+	 */
+	String ID_LABEL = "org.briarproject.bramble/HANDSHAKE_KEY_ID";
+}

bramble-api/src/main/java/org/briarproject/bramble/api/contact/HandshakeManager.java

@@ -0,0 +1,45 @@
+package org.briarproject.bramble.api.contact;
+
+import org.briarproject.bramble.api.crypto.SecretKey;
+import org.briarproject.bramble.api.db.DbException;
+import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
+import org.briarproject.bramble.api.transport.StreamWriter;
+
+import java.io.IOException;
+import java.io.InputStream;
+
+@NotNullByDefault
+public interface HandshakeManager {
+
+	/**
+	 * Handshakes with the given pending contact. Returns an ephemeral master
+	 * key authenticated with both parties' handshake key pairs and a flag
+	 * indicating whether the local peer is Alice or Bob.
+	 *
+	 * @param in An incoming stream for the handshake, which must be secured in
+	 * handshake mode
+	 * @param out An outgoing stream for the handshake, which must be secured
+	 * in handshake mode
+	 */
+	HandshakeResult handshake(PendingContactId p, InputStream in,
+			StreamWriter out) throws DbException, IOException;
+
+	class HandshakeResult {
+
+		private final SecretKey masterKey;
+		private final boolean alice;
+
+		public HandshakeResult(SecretKey masterKey, boolean alice) {
+			this.masterKey = masterKey;
+			this.alice = alice;
+		}
+
+		public SecretKey getMasterKey() {
+			return masterKey;
+		}
+
+		public boolean isAlice() {
+			return alice;
+		}
+	}
+}

bramble-api/src/main/java/org/briarproject/bramble/api/contact/PendingContact.java

@@ -0,0 +1,51 @@
+package org.briarproject.bramble.api.contact;
+
+import org.briarproject.bramble.api.crypto.PublicKey;
+import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
+
+import javax.annotation.concurrent.Immutable;
+
+@Immutable
+@NotNullByDefault
+public class PendingContact {
+
+	private final PendingContactId id;
+	private final PublicKey publicKey;
+	private final String alias;
+	private final long timestamp;
+
+	public PendingContact(PendingContactId id, PublicKey publicKey,
+			String alias, long timestamp) {
+		this.id = id;
+		this.publicKey = publicKey;
+		this.alias = alias;
+		this.timestamp = timestamp;
+	}
+
+	public PendingContactId getId() {
+		return id;
+	}
+
+	public PublicKey getPublicKey() {
+		return publicKey;
+	}
+
+	public String getAlias() {
+		return alias;
+	}
+
+	public long getTimestamp() {
+		return timestamp;
+	}
+
+	@Override
+	public int hashCode() {
+		return id.hashCode();
+	}
+
+	@Override
+	public boolean equals(Object o) {
+		return o instanceof PendingContact &&
+				id.equals(((PendingContact) o).id);
+	}
+}

bramble-api/src/main/java/org/briarproject/bramble/api/contact/PendingContactId.java

@@ -0,0 +1,25 @@
+package org.briarproject.bramble.api.contact;
+
+import org.briarproject.bramble.api.UniqueId;
+import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
+
+import javax.annotation.Nullable;
+import javax.annotation.concurrent.ThreadSafe;
+
+/**
+ * Type-safe wrapper for a byte array that uniquely identifies a
+ * {@link PendingContact}.
+ */
+@ThreadSafe
+@NotNullByDefault
+public class PendingContactId extends UniqueId {
+
+	public PendingContactId(byte[] id) {
+		super(id);
+	}
+
+	@Override
+	public boolean equals(@Nullable Object o) {
+		return o instanceof PendingContactId && super.equals(o);
+	}
+}

bramble-api/src/main/java/org/briarproject/bramble/api/contact/PendingContactState.java

@@ -0,0 +1,10 @@
+package org.briarproject.bramble.api.contact;
+
+public enum PendingContactState {
+
+	WAITING_FOR_CONNECTION,
+	OFFLINE,
+	CONNECTING,
+	ADDING_CONTACT,
+	FAILED
+}

bramble-api/src/main/java/org/briarproject/bramble/api/contact/event/ContactAddedEvent.java

@@ -0,0 +1,31 @@
+package org.briarproject.bramble.api.contact.event;
+
+import org.briarproject.bramble.api.contact.ContactId;
+import org.briarproject.bramble.api.event.Event;
+import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
+
+import javax.annotation.concurrent.Immutable;
+
+/**
+ * An event that is broadcast when a contact is added.
+ */
+@Immutable
+@NotNullByDefault
+public class ContactAddedEvent extends Event {
+
+	private final ContactId contactId;
+	private final boolean verified;
+
+	public ContactAddedEvent(ContactId contactId, boolean verified) {
+		this.contactId = contactId;
+		this.verified = verified;
+	}
+
+	public ContactId getContactId() {
+		return contactId;
+	}
+
+	public boolean isVerified() {
+		return verified;
+	}
+}

bramble-api/src/main/java/org/briarproject/bramble/api/contact/event/ContactRemovedEvent.java

@@ -0,0 +1,25 @@
+package org.briarproject.bramble.api.contact.event;
+
+import org.briarproject.bramble.api.contact.ContactId;
+import org.briarproject.bramble.api.event.Event;
+import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
+
+import javax.annotation.concurrent.Immutable;
+
+/**
+ * An event that is broadcast when a contact is removed.
+ */
+@Immutable
+@NotNullByDefault
+public class ContactRemovedEvent extends Event {
+
+	private final ContactId contactId;
+
+	public ContactRemovedEvent(ContactId contactId) {
+		this.contactId = contactId;
+	}
+
+	public ContactId getContactId() {
+		return contactId;
+	}
+}

bramble-api/src/main/java/org/briarproject/bramble/api/contact/event/ContactVerifiedEvent.java

@@ -0,0 +1,26 @@
+package org.briarproject.bramble.api.contact.event;
+
+import org.briarproject.bramble.api.contact.ContactId;
+import org.briarproject.bramble.api.event.Event;
+import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
+
+import javax.annotation.concurrent.Immutable;
+
+/**
+ * An event that is broadcast when a contact is verified.
+ */
+@Immutable
+@NotNullByDefault
+public class ContactVerifiedEvent extends Event {
+
+	private final ContactId contactId;
+
+	public ContactVerifiedEvent(ContactId contactId) {
+		this.contactId = contactId;
+	}
+
+	public ContactId getContactId() {
+		return contactId;
+	}
+
+}

bramble-api/src/main/java/org/briarproject/bramble/api/contact/event/PendingContactAddedEvent.java

@@ -0,0 +1,25 @@
+package org.briarproject.bramble.api.contact.event;
+
+import org.briarproject.bramble.api.contact.PendingContact;
+import org.briarproject.bramble.api.event.Event;
+import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
+
+import javax.annotation.concurrent.Immutable;
+
+/**
+ * An event that is broadcast when a pending contact is added.
+ */
+@Immutable
+@NotNullByDefault
+public class PendingContactAddedEvent extends Event {
+
+	private final PendingContact pendingContact;
+
+	public PendingContactAddedEvent(PendingContact pendingContact) {
+		this.pendingContact = pendingContact;
+	}
+
+	public PendingContact getPendingContact() {
+		return pendingContact;
+	}
+}

bramble-api/src/main/java/org/briarproject/bramble/api/contact/event/PendingContactRemovedEvent.java

@@ -0,0 +1,26 @@
+package org.briarproject.bramble.api.contact.event;
+
+import org.briarproject.bramble.api.contact.PendingContactId;
+import org.briarproject.bramble.api.event.Event;
+import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
+
+import javax.annotation.concurrent.Immutable;
+
+/**
+ * An event that is broadcast when a pending contact is removed.
+ */
+@Immutable
+@NotNullByDefault
+public class PendingContactRemovedEvent extends Event {
+
+	private final PendingContactId id;
+
+	public PendingContactRemovedEvent(PendingContactId id) {
+		this.id = id;
+	}
+
+	public PendingContactId getId() {
+		return id;
+	}
+
+}

bramble-api/src/main/java/org/briarproject/bramble/api/contact/event/PendingContactStateChangedEvent.java

@@ -0,0 +1,34 @@
+package org.briarproject.bramble.api.contact.event;
+
+import org.briarproject.bramble.api.contact.PendingContactId;
+import org.briarproject.bramble.api.contact.PendingContactState;
+import org.briarproject.bramble.api.event.Event;
+import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
+
+import javax.annotation.concurrent.Immutable;
+
+/**
+ * An event that is broadcast when a pending contact's state is changed.
+ */
+@Immutable
+@NotNullByDefault
+public class PendingContactStateChangedEvent extends Event {
+
+	private final PendingContactId id;
+	private final PendingContactState state;
+
+	public PendingContactStateChangedEvent(PendingContactId id,
+			PendingContactState state) {
+		this.id = id;
+		this.state = state;
+	}
+
+	public PendingContactId getId() {
+		return id;
+	}
+
+	public PendingContactState getPendingContactState() {
+		return state;
+	}
+
+}

bramble-api/src/main/java/org/briarproject/bramble/api/crypto/AgreementPrivateKey.java

@@ -0,0 +1,30 @@
+package org.briarproject.bramble.api.crypto;
+
+import org.briarproject.bramble.api.Bytes;
+import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
+
+import javax.annotation.concurrent.Immutable;
+
+import static org.briarproject.bramble.api.crypto.CryptoConstants.KEY_TYPE_AGREEMENT;
+
+/**
+ * Type-safe wrapper for a private key used for key agreement.
+ */
+@Immutable
+@NotNullByDefault
+public class AgreementPrivateKey extends Bytes implements PrivateKey {
+
+	public AgreementPrivateKey(byte[] encoded) {
+		super(encoded);
+	}
+
+	@Override
+	public String getKeyType() {
+		return KEY_TYPE_AGREEMENT;
+	}
+
+	@Override
+	public byte[] getEncoded() {
+		return getBytes();
+	}
+}

bramble-api/src/main/java/org/briarproject/bramble/api/crypto/AgreementPublicKey.java

@@ -0,0 +1,35 @@
+package org.briarproject.bramble.api.crypto;
+
+import org.briarproject.bramble.api.Bytes;
+import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
+
+import javax.annotation.concurrent.Immutable;
+
+import static org.briarproject.bramble.api.crypto.CryptoConstants.KEY_TYPE_AGREEMENT;
+import static org.briarproject.bramble.api.crypto.CryptoConstants.MAX_AGREEMENT_PUBLIC_KEY_BYTES;
+
+/**
+ * Type-safe wrapper for a public key used for key agreement.
+ */
+@Immutable
+@NotNullByDefault
+public class AgreementPublicKey extends Bytes implements PublicKey {
+
+	public AgreementPublicKey(byte[] encoded) {
+		super(encoded);
+		if (encoded.length == 0 ||
+				encoded.length > MAX_AGREEMENT_PUBLIC_KEY_BYTES) {
+			throw new IllegalArgumentException();
+		}
+	}
+
+	@Override
+	public String getKeyType() {
+		return KEY_TYPE_AGREEMENT;
+	}
+
+	@Override
+	public byte[] getEncoded() {
+		return getBytes();
+	}
+}

bramble-api/src/main/java/org/briarproject/bramble/api/crypto/CryptoComponent.java

@@ -0,0 +1,172 @@
+package org.briarproject.bramble.api.crypto;
+
+import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
+
+import java.security.GeneralSecurityException;
+import java.security.SecureRandom;
+
+import javax.annotation.Nullable;
+
+@NotNullByDefault
+public interface CryptoComponent {
+
+	SecretKey generateSecretKey();
+
+	SecureRandom getSecureRandom();
+
+	KeyPair generateAgreementKeyPair();
+
+	KeyParser getAgreementKeyParser();
+
+	KeyPair generateSignatureKeyPair();
+
+	KeyParser getSignatureKeyParser();
+
+	KeyParser getMessageKeyParser();
+
+	/**
+	 * Derives another secret key from the given secret key.
+	 *
+	 * @param label A namespaced label indicating the purpose of the derived
+	 * key, to prevent it from being repurposed or colliding with a key derived
+	 * for another purpose
+	 * @param inputs Additional inputs that will be included in the derivation
+	 * of the key
+	 */
+	SecretKey deriveKey(String label, SecretKey k, byte[]... inputs);
+
+	/**
+	 * Derives a shared secret from two key pairs.
+	 *
+	 * @param label A namespaced label indicating the purpose of this shared
+	 * secret, to prevent it from being repurposed or colliding with a shared
+	 * secret derived for another purpose
+	 * @param theirPublicKey The public key of the remote party
+	 * @param ourKeyPair The key pair of the local party
+	 * @param inputs Additional inputs that will be included in the derivation
+	 * of the shared secret
+	 * @return The shared secret
+	 */
+	SecretKey deriveSharedSecret(String label, PublicKey theirPublicKey,
+			KeyPair ourKeyPair, byte[]... inputs)
+			throws GeneralSecurityException;
+
+	/**
+	 * Derives a shared secret from two static and two ephemeral key pairs.
+	 *
+	 * @param label A namespaced label indicating the purpose of this shared
+	 * secret, to prevent it from being repurposed or colliding with a shared
+	 * secret derived for another purpose
+	 * @param theirStaticPublicKey The static public key of the remote party
+	 * @param theirEphemeralPublicKey The ephemeral public key of the remote
+	 * party
+	 * @param ourStaticKeyPair The static key pair of the local party
+	 * @param ourEphemeralKeyPair The ephemeral key pair of the local party
+	 * @param alice True if the local party is Alice
+	 * @param inputs Additional inputs that will be included in the
+	 * derivation of the shared secret
+	 * @return The shared secret
+	 */
+	SecretKey deriveSharedSecret(String label, PublicKey theirStaticPublicKey,
+			PublicKey theirEphemeralPublicKey, KeyPair ourStaticKeyPair,
+			KeyPair ourEphemeralKeyPair, boolean alice, byte[]... inputs)
+			throws GeneralSecurityException;
+
+	/**
+	 * Signs the given byte[] with the given private key.
+	 *
+	 * @param label A namespaced label indicating the purpose of this
+	 * signature, to prevent it from being repurposed or colliding with a
+	 * signature created for another purpose
+	 */
+	byte[] sign(String label, byte[] toSign, PrivateKey privateKey)
+			throws GeneralSecurityException;
+
+	/**
+	 * Verifies that the given signature is valid for the signed data
+	 * and the given public key.
+	 *
+	 * @param label A namespaced label indicating the purpose of this
+	 * signature, to prevent it from being repurposed or colliding with a
+	 * signature created for another purpose
+	 * @return True if the signature was valid, false otherwise.
+	 */
+	boolean verifySignature(byte[] signature, String label, byte[] signed,
+			PublicKey publicKey) throws GeneralSecurityException;
+
+	/**
+	 * Returns the hash of the given inputs. The inputs are unambiguously
+	 * combined by prefixing each input with its length.
+	 *
+	 * @param label A namespaced label indicating the purpose of this hash, to
+	 * prevent it from being repurposed or colliding with a hash created for
+	 * another purpose
+	 */
+	byte[] hash(String label, byte[]... inputs);
+
+	/**
+	 * Returns a message authentication code with the given key over the
+	 * given inputs. The inputs are unambiguously combined by prefixing each
+	 * input with its length.
+	 *
+	 * @param label A namespaced label indicating the purpose of this MAC, to
+	 * prevent it from being repurposed or colliding with a MAC created for
+	 * another purpose
+	 */
+	byte[] mac(String label, SecretKey macKey, byte[]... inputs);
+
+	/**
+	 * Verifies that the given message authentication code is valid for the
+	 * given secret key and inputs.
+	 *
+	 * @param label A namespaced label indicating the purpose of this MAC, to
+	 * prevent it from being repurposed or colliding with a MAC created for
+	 * another purpose
+	 * @return True if the MAC was valid, false otherwise.
+	 */
+	boolean verifyMac(byte[] mac, String label, SecretKey macKey,
+			byte[]... inputs);
+
+	/**
+	 * Encrypts and authenticates the given plaintext so it can be written to
+	 * storage. The encryption and authentication keys are derived from the
+	 * given password. The ciphertext will be decryptable using the same
+	 * password after the app restarts.
+	 *
+	 * @param keyStrengthener Used to strengthen the password-based key. If
+	 * null, the password-based key will not be strengthened
+	 */
+	byte[] encryptWithPassword(byte[] plaintext, String password,
+			@Nullable KeyStrengthener keyStrengthener);
+
+	/**
+	 * Decrypts and authenticates the given ciphertext that has been read from
+	 * storage. The encryption and authentication keys are derived from the
+	 * given password. Returns null if the ciphertext cannot be decrypted and
+	 * authenticated (for example, if the password is wrong).
+	 *
+	 * @param keyStrengthener Used to strengthen the password-based key. If
+	 * null, or if strengthening was not used when encrypting the ciphertext,
+	 * the password-based key will not be strengthened
+	 */
+	@Nullable
+	byte[] decryptWithPassword(byte[] ciphertext, String password,
+			@Nullable KeyStrengthener keyStrengthener);
+
+	/**
+	 * Returns true if the given ciphertext was encrypted using a strengthened
+	 * key. The validity of the ciphertext is not checked.
+	 */
+	boolean isEncryptedWithStrengthenedKey(byte[] ciphertext);
+
+	/**
+	 * Encrypts the given plaintext to the given public key.
+	 */
+	byte[] encryptToKey(PublicKey publicKey, byte[] plaintext);
+
+	/**
+	 * Encodes the given data as a hex string divided into lines of the given
+	 * length. The line terminator is CRLF.
+	 */
+	String asciiArmour(byte[] b, int lineLength);
+}

bramble-api/src/main/java/org/briarproject/bramble/api/crypto/CryptoConstants.java

@@ -0,0 +1,35 @@
+package org.briarproject.bramble.api.crypto;
+
+public interface CryptoConstants {
+
+	/**
+	 * The maximum length of an agreement public key in bytes.
+	 */
+	int MAX_AGREEMENT_PUBLIC_KEY_BYTES = 32;
+
+	/**
+	 * The key type for agreement key pairs.
+	 */
+	String KEY_TYPE_AGREEMENT = "Curve25519";
+
+	/**
+	 * The maximum length of a signature public key in bytes.
+	 */
+	int MAX_SIGNATURE_PUBLIC_KEY_BYTES = 32;
+
+	/**
+	 * The key type for signature key pairs.
+	 */
+	String KEY_TYPE_SIGNATURE = "Ed25519";
+
+	/**
+	 * The maximum length of a signature in bytes.
+	 */
+	int MAX_SIGNATURE_BYTES = 64;
+
+	/**
+	 * The length of a MAC in bytes.
+	 */
+	int MAC_BYTES = SecretKey.LENGTH;
+
+}

bramble-api/src/main/java/org/briarproject/bramble/api/crypto/CryptoExecutor.java

@@ -0,0 +1,25 @@
+package org.briarproject.bramble.api.crypto;
+
+import java.lang.annotation.Retention;
+import java.lang.annotation.Target;
+
+import javax.inject.Qualifier;
+
+import static java.lang.annotation.ElementType.FIELD;
+import static java.lang.annotation.ElementType.METHOD;
+import static java.lang.annotation.ElementType.PARAMETER;
+import static java.lang.annotation.RetentionPolicy.RUNTIME;
+
+/**
+ * Annotation for injecting the executor for long-running crypto tasks. Also
+ * used for annotating methods that should run on the crypto executor.
+ * <p>
+ * The contract of this executor is that tasks may be run concurrently, and
+ * submitting a task will never block. Tasks must not run indefinitely. Tasks
+ * submitted during shutdown are discarded.
+ */
+@Qualifier
+@Target({FIELD, METHOD, PARAMETER})
+@Retention(RUNTIME)
+public @interface CryptoExecutor {
+}

bramble-api/src/main/java/org/briarproject/bramble/api/crypto/KeyAgreementCrypto.java

@@ -0,0 +1,50 @@
+package org.briarproject.bramble.api.crypto;
+
+/**
+ * Crypto operations for the key agreement protocol - see
+ * https://code.briarproject.org/briar/briar-spec/blob/master/protocols/BQP.md
+ */
+public interface KeyAgreementCrypto {
+
+	/**
+	 * Hash label for public key commitment.
+	 */
+	String COMMIT_LABEL = "org.briarproject.bramble.keyagreement/COMMIT";
+
+	/**
+	 * Key derivation label for confirmation record.
+	 */
+	String CONFIRMATION_KEY_LABEL =
+			"org.briarproject.bramble.keyagreement/CONFIRMATION_KEY";
+
+	/**
+	 * MAC label for confirmation record.
+	 */
+	String CONFIRMATION_MAC_LABEL =
+			"org.briarproject.bramble.keyagreement/CONFIRMATION_MAC";
+
+	/**
+	 * Derives a commitment to the provided public key.
+	 *
+	 * @param publicKey the public key
+	 * @return the commitment to the provided public key.
+	 */
+	byte[] deriveKeyCommitment(PublicKey publicKey);
+
+	/**
+	 * Derives the content of a confirmation record.
+	 *
+	 * @param sharedSecret the common shared secret
+	 * @param theirPayload the key exchange payload of the remote party
+	 * @param ourPayload the key exchange payload of the local party
+	 * @param theirPublicKey the ephemeral public key of the remote party
+	 * @param ourKeyPair our ephemeral key pair of the local party
+	 * @param alice true if the local party is Alice
+	 * @param aliceRecord true if the confirmation record is for use by Alice
+	 * @return the confirmation record
+	 */
+	byte[] deriveConfirmationRecord(SecretKey sharedSecret,
+			byte[] theirPayload, byte[] ourPayload,
+			PublicKey theirPublicKey, KeyPair ourKeyPair,
+			boolean alice, boolean aliceRecord);
+}

bramble-api/src/main/java/org/briarproject/bramble/api/crypto/KeyPair.java

@@ -0,0 +1,31 @@
+package org.briarproject.bramble.api.crypto;
+
+import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
+
+import javax.annotation.concurrent.Immutable;
+
+/**
+ * A key pair consisting of a {@link PublicKey} and a {@link PrivateKey}.
+ */
+@Immutable
+@NotNullByDefault
+public class KeyPair {
+
+	private final PublicKey publicKey;
+	private final PrivateKey privateKey;
+
+	public KeyPair(PublicKey publicKey, PrivateKey privateKey) {
+		if (!publicKey.getKeyType().equals(privateKey.getKeyType()))
+			throw new IllegalArgumentException();
+		this.publicKey = publicKey;
+		this.privateKey = privateKey;
+	}
+
+	public PublicKey getPublic() {
+		return publicKey;
+	}
+
+	public PrivateKey getPrivate() {
+		return privateKey;
+	}
+}

bramble-api/src/main/java/org/briarproject/bramble/api/crypto/KeyParser.java

@@ -0,0 +1,14 @@
+package org.briarproject.bramble.api.crypto;
+
+import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
+
+import java.security.GeneralSecurityException;
+
+@NotNullByDefault
+public interface KeyParser {
+
+	PublicKey parsePublicKey(byte[] encodedKey) throws GeneralSecurityException;
+
+	PrivateKey parsePrivateKey(byte[] encodedKey)
+			throws GeneralSecurityException;
+}

bramble-api/src/main/java/org/briarproject/bramble/api/crypto/KeyStrengthener.java

@@ -0,0 +1,23 @@
+package org.briarproject.bramble.api.crypto;
+
+import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
+
+/**
+ * Interface for strengthening a password-based key, for example by using a
+ * key stored in a key management service or hardware security module.
+ */
+@NotNullByDefault
+public interface KeyStrengthener {
+
+	/**
+	 * Returns true if the strengthener has been initialised.
+	 */
+	@SuppressWarnings("BooleanMethodIsAlwaysInverted")
+	boolean isInitialised();
+
+	/**
+	 * Initialises the strengthener if necessary and returns a strong key
+	 * derived from the given key.
+	 */
+	SecretKey strengthenKey(SecretKey k);
+}

bramble-api/src/main/java/org/briarproject/bramble/api/crypto/PasswordStrengthEstimator.java

@@ -0,0 +1,19 @@
+package org.briarproject.bramble.api.crypto;
+
+import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
+
+@NotNullByDefault
+public interface PasswordStrengthEstimator {
+
+	float NONE = 0;
+	float WEAK = 0.25f;
+	float QUITE_WEAK = 0.5f;
+	float QUITE_STRONG = 0.75f;
+	float STRONG = 1;
+
+	/**
+	 * Returns an estimate between 0 (weakest) and 1 (strongest), inclusive,
+	 * of the strength of the given password.
+	 */
+	float estimateStrength(String password);
+}

bramble-api/src/main/java/org/briarproject/bramble/api/crypto/PrivateKey.java

@@ -0,0 +1,20 @@
+package org.briarproject.bramble.api.crypto;
+
+import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
+
+/**
+ * The private half of a public/private {@link KeyPair}.
+ */
+@NotNullByDefault
+public interface PrivateKey {
+
+	/**
+	 * Returns the type of this key pair.
+	 */
+	String getKeyType();
+
+	/**
+	 * Returns the encoded representation of this key.
+	 */
+	byte[] getEncoded();
+}

bramble-api/src/main/java/org/briarproject/bramble/api/crypto/PublicKey.java

@@ -0,0 +1,20 @@
+package org.briarproject.bramble.api.crypto;
+
+import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
+
+/**
+ * The public half of a public/private {@link KeyPair}.
+ */
+@NotNullByDefault
+public interface PublicKey {
+
+	/**
+	 * Returns the type of this key pair.
+	 */
+	String getKeyType();
+
+	/**
+	 * Returns the encoded representation of this key.
+	 */
+	byte[] getEncoded();
+}

bramble-api/src/main/java/org/briarproject/bramble/api/crypto/SecretKey.java

@@ -0,0 +1,23 @@
+package org.briarproject.bramble.api.crypto;
+
+/**
+ * A secret key used for encryption and/or authentication.
+ */
+public class SecretKey {
+
+	/**
+	 * The length of a secret key in bytes.
+	 */
+	public static final int LENGTH = 32;
+
+	private final byte[] key;
+
+	public SecretKey(byte[] key) {
+		if (key.length != LENGTH) throw new IllegalArgumentException();
+		this.key = key;
+	}
+
+	public byte[] getBytes() {
+		return key;
+	}
+}

bramble-api/src/main/java/org/briarproject/bramble/api/crypto/SignaturePrivateKey.java

@@ -0,0 +1,30 @@
+package org.briarproject.bramble.api.crypto;
+
+import org.briarproject.bramble.api.Bytes;
+import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
+
+import javax.annotation.concurrent.Immutable;
+
+import static org.briarproject.bramble.api.crypto.CryptoConstants.KEY_TYPE_SIGNATURE;
+
+/**
+ * Type-safe wrapper for a public key used for signing.
+ */
+@Immutable
+@NotNullByDefault
+public class SignaturePrivateKey extends Bytes implements PrivateKey {
+
+	public SignaturePrivateKey(byte[] bytes) {
+		super(bytes);
+	}
+
+	@Override
+	public String getKeyType() {
+		return KEY_TYPE_SIGNATURE;
+	}
+
+	@Override
+	public byte[] getEncoded() {
+		return getBytes();
+	}
+}

bramble-api/src/main/java/org/briarproject/bramble/api/crypto/SignaturePublicKey.java

@@ -0,0 +1,35 @@
+package org.briarproject.bramble.api.crypto;
+
+import org.briarproject.bramble.api.Bytes;
+import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
+
+import javax.annotation.concurrent.Immutable;
+
+import static org.briarproject.bramble.api.crypto.CryptoConstants.KEY_TYPE_SIGNATURE;
+import static org.briarproject.bramble.api.crypto.CryptoConstants.MAX_SIGNATURE_PUBLIC_KEY_BYTES;
+
+/**
+ * Type-safe wrapper for a public key used for verifying signatures.
+ */
+@Immutable
+@NotNullByDefault
+public class SignaturePublicKey extends Bytes implements PublicKey {
+
+	public SignaturePublicKey(byte[] encoded) {
+		super(encoded);
+		if (encoded.length == 0 ||
+				encoded.length > MAX_SIGNATURE_PUBLIC_KEY_BYTES) {
+			throw new IllegalArgumentException();
+		}
+	}
+
+	@Override
+	public String getKeyType() {
+		return KEY_TYPE_SIGNATURE;
+	}
+
+	@Override
+	public byte[] getEncoded() {
+		return getBytes();
+	}
+}

bramble-api/src/main/java/org/briarproject/bramble/api/crypto/StreamDecrypter.java

@@ -0,0 +1,18 @@
+package org.briarproject.bramble.api.crypto;
+
+import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
+
+import java.io.IOException;
+
+@NotNullByDefault
+public interface StreamDecrypter {
+
+	/**
+	 * Reads a frame, decrypts its payload into the given buffer and returns
+	 * the payload length, or -1 if no more frames can be read from the stream.
+	 *
+	 * @throws IOException if an error occurs while reading the frame,
+	 * or if authenticated decryption fails.
+	 */
+	int readFrame(byte[] payload) throws IOException;
+}

bramble-api/src/main/java/org/briarproject/bramble/api/crypto/StreamDecrypterFactory.java

@@ -0,0 +1,22 @@
+package org.briarproject.bramble.api.crypto;
+
+import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
+import org.briarproject.bramble.api.transport.StreamContext;
+
+import java.io.InputStream;
+
+@NotNullByDefault
+public interface StreamDecrypterFactory {
+
+	/**
+	 * Creates a {@link StreamDecrypter} for decrypting a transport stream.
+	 */
+	StreamDecrypter createStreamDecrypter(InputStream in, StreamContext ctx);
+
+	/**
+	 * Creates a {@link StreamDecrypter} for decrypting a contact exchange
+	 * stream.
+	 */
+	StreamDecrypter createContactExchangeStreamDecrypter(InputStream in,
+			SecretKey headerKey);
+}

bramble-api/src/main/java/org/briarproject/bramble/api/crypto/StreamEncrypter.java

@@ -0,0 +1,20 @@
+package org.briarproject.bramble.api.crypto;
+
+import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
+
+import java.io.IOException;
+
+@NotNullByDefault
+public interface StreamEncrypter {
+
+	/**
+	 * Encrypts the given frame and writes it to the stream.
+	 */
+	void writeFrame(byte[] payload, int payloadLength, int paddingLength,
+			boolean finalFrame) throws IOException;
+
+	/**
+	 * Flushes the stream.
+	 */
+	void flush() throws IOException;
+}

bramble-api/src/main/java/org/briarproject/bramble/api/crypto/StreamEncrypterFactory.java

@@ -0,0 +1,22 @@
+package org.briarproject.bramble.api.crypto;
+
+import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
+import org.briarproject.bramble.api.transport.StreamContext;
+
+import java.io.OutputStream;
+
+@NotNullByDefault
+public interface StreamEncrypterFactory {
+
+	/**
+	 * Creates a {@link StreamEncrypter} for encrypting a transport stream.
+	 */
+	StreamEncrypter createStreamEncrypter(OutputStream out, StreamContext ctx);
+
+	/**
+	 * Creates a {@link StreamEncrypter} for encrypting a contact exchange
+	 * stream.
+	 */
+	StreamEncrypter createContactExchangeStreamDecrypter(OutputStream out,
+			SecretKey headerKey);
+}