Added cross-compilation support for Android.

Author: oliver-schick

.gitignore

@@ -11,10 +11,12 @@
 README.html
 docs/*
 *.dump
-
+*.bak
 
 # build directory
 build*/
+# extern directory
+extern/*
 
 # CMake
 CMakeCache.txt

.gitmodules

@@ -1,6 +1,3 @@
-[submodule "extern/ENCRYPTO_utils"]
-	path = extern/ENCRYPTO_utils
-	url = https://github.com/encryptogroup/ENCRYPTO_utils.git
-[submodule "extern/OTExtension"]
-	path = extern/OTExtension
-	url = https://github.com/encryptogroup/OTExtension.git
+[submodule "extern/boost-cmake"]
+	path = extern/boost-cmake
+	url = https://github.com/Orphis/boost-cmake.git

CMakeLists.txt

@@ -1,22 +1,8 @@
-cmake_minimum_required(VERSION 3.12)
-project(ABY LANGUAGES CXX)
-
-if (CMAKE_COMPILER_IS_GNUCXX AND CMAKE_CXX_COMPILER_VERSION VERSION_LESS 8.0)
-    message(FATAL_ERROR "ABY requires at least g++-8")
-endif()
-
-option(ABY_BUILD_EXE "Build executables" OFF)
-
-list(APPEND CMAKE_MODULE_PATH "${CMAKE_CURRENT_LIST_DIR}/cmake")
-
-# Set build type to `Release` if non was specified:
-# (cf. https://gitlab.kitware.com/cmake/community/wikis/FAQ#how-can-i-change-the-default-build-mode-and-see-it-reflected-in-the-gui)
-if(NOT CMAKE_BUILD_TYPE)
-    set(CMAKE_BUILD_TYPE Release CACHE STRING
-      "Choose the type of build, options are: None Debug Release RelWithDebInfo MinSizeRel."
-      FORCE)
-endif(NOT CMAKE_BUILD_TYPE)
-
+cmake_minimum_required(VERSION 3.13)
+list(INSERT CMAKE_MODULE_PATH 0 "${CMAKE_CURRENT_LIST_DIR}/cmake/Modules")
+include(ABYCacheVariables)
+set(CMAKE_CXX_STANDARD 14)
+project(ABY LANGUAGES C CXX)
 # Write built executables and libraries to bin/ and lib/, respectively.
 if(NOT CMAKE_RUNTIME_OUTPUT_DIRECTORY)
     set(CMAKE_RUNTIME_OUTPUT_DIRECTORY "${PROJECT_BINARY_DIR}/bin")
@@ -27,43 +13,14 @@ endif()
 if(NOT CMAKE_ARCHIVE_OUTPUT_DIRECTORY)
     set(CMAKE_ARCHIVE_OUTPUT_DIRECTORY "${PROJECT_BINARY_DIR}/lib")
 endif()
-
-find_package(ENCRYPTO_utils QUIET)
-if(ENCRYPTO_utils_FOUND)
-    message(STATUS "Found ENCRYPTO_utils")
-elseif(NOT ENCRYPTO_utils_FOUND AND NOT TARGET ENCRYPTO_utils::encrypto_utils)
-    message("ENCRYPTO_utils was not found: add ENCRYPTO_utils subdirectory")
-    if(NOT EXISTS "${PROJECT_SOURCE_DIR}/extern/ENCRYPTO_utils/CMakeLists.txt")
-        find_package(Git REQUIRED)
-        message("initialize Git submodule: extern/ENCRYPTO_utils")
-        execute_process(COMMAND git submodule update --init extern/ENCRYPTO_utils
-                        WORKING_DIRECTORY "${PROJECT_SOURCE_DIR}")
-    endif()
-    add_subdirectory(extern/ENCRYPTO_utils)
-endif()
-
-find_package(OTExtension QUIET)
-if(OTExtension_FOUND)
-    message(STATUS "Found OTExtension")
-elseif (NOT OTExtension_FOUND AND NOT TARGET OTExtension::otextension)
-    message("OTExtension was not found: add OTExtension subdirectory")
-    if(NOT EXISTS "${PROJECT_SOURCE_DIR}/extern/OTExtension/CMakeLists.txt")
-        find_package(Git REQUIRED)
-        message("initialize Git submodule: extern/OTExtension")
-        execute_process(COMMAND git submodule update --init extern/OTExtension
-                        WORKING_DIRECTORY "${PROJECT_SOURCE_DIR}")
-    endif()
-    add_subdirectory(extern/OTExtension)
+if(ANDROID)
+    add_definitions(-DANDROID)
 endif()
 
-find_package(GMP REQUIRED)
-find_package(Threads REQUIRED)
-find_package(Boost 1.66.0 REQUIRED COMPONENTS thread system)
-
 add_subdirectory(src/abycore)
 
-
 if(ABY_BUILD_EXE)
     add_subdirectory(src/test)
     add_subdirectory(src/examples)
 endif(ABY_BUILD_EXE)
+

README.md

@@ -20,13 +20,13 @@ By *Daniel Demmler, Thomas Schneider and Michael Zohner* ([ENCRYPTO](http://www.
             - [Build Options](#build-options)
             - [Cleaning the Build Directory](#cleaning-the-build-directory)
             - [Installation](#installation)
-    - [Developer Guide and Documentation](#developer-guide-and-documentation)
+    - [Building for Android](#building-for-android)
+    - [Developer Guide and Documentation](#developer-guide-and-documentation) 
 - [ABY Applications](#aby-applications)
     - [Included Example Applications](#included-example-applications)
     - [Running Applications](#running-applications)
     - [Creating and Building your own ABY Application](#creating-and-building-your-own-aby-application)
 
-
 ### Features
 ---
 ABY efficiently combines secure computation schemes based on **Arithmetic sharing**, **Boolean sharing**, and **Yao’s garbled circuits** and makes available best-practice solutions in secure two-party computation.
@@ -182,12 +182,36 @@ make
 make install
 ```
 
-
 #### Developer Guide and Documentation
 We provide an extensive [developer guide](https://www.informatik.tu-darmstadt.de/media/encrypto/encrypto_code/abydevguide.pdf) with many examples and explanations of how to use ABY.
 
 Also, see the [online doxygen documentation of ABY](http://encryptogroup.github.io/ABY/docs/index.html) for further information and comments on the code.
 
+## Building for Android
+
+1. Clone the ABY git repository by running:
+    ```
+    git clone https://github.com/encryptogroup/ABY.git
+    ```
+
+2. Enter the Framework directory: `cd ABY/`
+
+3. Create and enter the build directory: `mkdir build && cd build`
+
+4. Use CMake to configure the build and setting android variables:
+    ```
+    cmake -DANDROID_NDK=<path/to/ndk> -DANDROID_NATIVE_API_LEVEL=<TargetAPI> -DANDROID_ABI=<TargetABI> ..
+    ```
+    where <TargetAPI> is a number between 16 and the latest Android API and <TargetABI> is the target platform (one of armeabi-v7a, arm64-v8a, x86 and x86_64 respectively).
+    
+    Please note that when using ABY with Android Studio that <path/to/ndk> needs to be the path to the NDK used by Android Studio (often located at $HOME/Android/Sdk/ndk-bundle on Linux).
+    
+
+5. Call `make` in the build directory.
+   You can find the build executables and libraries in the directories `bin/`
+   and `lib/`, respectively.
+
+6. Call 'make install' after the build has finished. This will install the libraries into the provided NDK.
 
 ### ABY Applications
 ---
@@ -234,6 +258,8 @@ Also, see the [online doxygen documentation of ABY](http://encryptogroup.github.
 	add_executable(my_application my_application.cpp)
 	target_link_libraries(my_application ABY::aby)
 	```
+* If you are using ABY for Android in Android Studio and you encounter the "library libc++_shared.so not found" error, make sure to pass '-DANDROID_STL=c++_shared' as an argument to cmake within the gradle script. Setting ANDROID_STL within the cmake script won't work.
+
 * Otherwise, setup the include path such that the headers of ABY and its
   dependencies can be found and link your application to the `libaby.a`
   library and the other dependencies (see above).

cmake/ABYConfig.cmake.in

@@ -1,15 +1,20 @@
 get_filename_component(ABY_CMAKE_DIR "${CMAKE_CURRENT_LIST_FILE}" PATH)
 
-list(APPEND CMAKE_MODULE_PATH "${ABY_CMAKE_DIR}")
-
 include(CMakeFindDependencyMacro)
 
+find_dependency(Boost)
 find_dependency(OTExtension)
 find_dependency(ENCRYPTO_utils)
-find_dependency(MIRACL)
 find_dependency(GMP)
 find_dependency(Threads)
 
 if(NOT TARGET ABY::aby)
     include("${ABY_CMAKE_DIR}/ABYTargets.cmake")
 endif()
+
+if(TARGET ABY::aby)
+    set(ABY_FOUND TRUE)
+    set(TARGETS ABY::aby)
+endif()
+
+

cmake/BoostConfig.cmake.in

@@ -0,0 +1,5 @@
+get_filename_component(Boost_CMAKE_DIR "${CMAKE_CURRENT_LIST_FILE}" PATH)
+
+if(NOT TARGET Boost::boost)
+    include("${Boost_CMAKE_DIR}/BoostTargets.cmake")
+endif()

cmake/FindGMP.cmake

@@ -0,0 +1,14 @@
+include(CMakeFindDependencyMacro)
+set(INSTALL_NAME "@INSTALL_NAME@")
+if(ANDROID AND ANDROID_ARM_NEON)
+    set(PREFIX "${INSTALL_NAME}-${ANDROID_PLATFORM}-${ANDROID_SYSROOT_ABI}-NEON")
+elseif(ANDROID AND NOT ANDROID_ARM_NEON)
+    set(PREFIX "${INSTALL_NAME}-${ANDROID_PLATFORM}-${ANDROID_SYSROOT_ABI}")
+else()
+    set(PREFIX "${INSTALL_NAME}")
+endif()
+if(EXISTS "${CMAKE_CURRENT_LIST_DIR}/${PREFIX}/${PREFIX}Config.cmake")
+    include("${CMAKE_CURRENT_LIST_DIR}/${PREFIX}/${PREFIX}Config.cmake")
+else()
+    set(${INSTALL_NAME}_FOUND FALSE)
+endif()

cmake/FindGMPXX.cmake

@@ -0,0 +1,35 @@
+if(NOT "${GMP_LIBRARY_TYPE}" STREQUAL "STATIC" AND NOT "${GMP_LIBRARY_TYPE}" STREQUAL "SHARED")
+    set(GMP_LIBRARY_TYPE "@GMP_LIBRARY_TYPE@")
+endif()
+set(LIB_PREFIX "${CMAKE_${GMP_LIBRARY_TYPE}_LIBRARY_PREFIX}")
+set(LIB_SUFFIX "${CMAKE_${GMP_LIBRARY_TYPE}_LIBRARY_SUFFIX}")
+
+set(GMP_INCLUDE_PATHS "@INSTALL_CONFIG_INCLUDE_PATHS@")
+set(GMP_LIB_PATHS "@INSTALL_CONFIG_LIB_PATHS@")
+
+unset(GMP_INCLUDE_DIR CACHE)
+unset(GMP_LIBRARY CACHE)
+
+find_path(GMP_INCLUDE_DIR gmp.h PATHS ${GMP_INCLUDE_PATHS})
+find_library(GMP_LIBRARY NAMES ${LIB_PREFIX}gmp${LIB_SUFFIX} PATHS ${GMP_LIB_PATHS})
+
+if(EXISTS "${GMP_INCLUDE_DIR}" AND EXISTS "${GMP_LIBRARY}")
+    set(GMP_FOUND TRUE)
+else()
+    set(GMP_LIBRARY )
+    set(GMP_FOUND FALSE)
+endif()
+
+if(GMP_FOUND AND NOT TARGET GMP::GMP)
+    add_library(GMP::GMP "${GMP_LIBRARY_TYPE}" IMPORTED)
+    set_target_properties(GMP::GMP PROPERTIES 
+                                   IMPORTED_LOCATION "${GMP_LIBRARY}"
+                                   INTERFACE_INCLUDE_DIRECTORIES "${GMP_INCLUDE_DIR}")
+endif()
+
+mark_as_advanced(
+    GMP_INCLUDE_DIR
+    GMP_LIBRARY
+)
+
+set(TARGETS GMP::GMP)