Android Libcurl (#99)

Author: Luke

.github/workflows/build_android.yml

@@ -5,7 +5,7 @@ jobs:
     timeout-minutes: 30
     strategy:
       matrix:
-        preset: ["android-armeabi-v7a-host_linux-x64", "android-arm64-v8a-host_linux-x64", "android-x64-host_linux-x64"]
+        preset: ["android-arm64-v8a-host_osx_x64", "android-x64-host_osx_x64"]
     runs-on: ubuntu-22.04
     steps:
       - uses: actions/checkout@v3

.gitignore

@@ -4,4 +4,11 @@ out
 .idea
 /test/Engine
 CMakeUserPresets.json
-local.properties
+local.properties
+
+# Ignore Gradle project-specific cache directory
+android/.gradle
+
+# Ignore Gradle build output directory
+android/build
+android/app/.cxx

CMakeLists.txt

@@ -1,7 +1,7 @@
-cmake_minimum_required(VERSION 3.23)
+# I think we are constrained to the version that the latest android sdk uses, for Android builds.
+cmake_minimum_required(VERSION 3.22.1)
 include(version.cmake)
 
-
 if (CMAKE_OSX_SYSROOT STREQUAL "iphonesimulator")
     # this hack seems to be required for now, otherwise CMake still thinks we are building for arm...
     set(CMAKE_XCODE_ATTRIBUTE_EXCLUDED_ARCHS[sdk=iphonesimulator*] "arm64")
@@ -50,6 +50,8 @@ else()
         set(HTTP_IMPL "libhttpclient")
     elseif (WITH_CPPRESTSDK)
         set(HTTP_IMPL "cpprestsdk")
+    elseif (BUILD_CURL_HTTP)
+        set(HTTP_IMPL "curl")
     endif()
 
     if (WITH_LIBHTTPCLIENT_WS)
@@ -63,18 +65,21 @@ endif()
 
 if (DEFINED ANDROID_ABI)
     if (DEFINED VCPKG_CHAINLOAD_TOOLCHAIN_FILE)
-        message(FATAL "Cannot specify an external chainload toolchain if building for Android.")
+        message(FATAL_ERROR "Cannot specify an external chainload toolchain if building for Android.")
     endif()
 
     set(VCPKG_CHAINLOAD_TOOLCHAIN_FILE $ENV{ANDROID_NDK_HOME}/build/cmake/android.toolchain.cmake)
 endif()
 
 cmake_policy(SET CMP0012 NEW)
 
-# Kickstarts vcpkg dependency manager. It will parse vcpkg.json and install all configured
-# dependencies. Some dependencies are optional and enabled via VCPKG_MANIFEST_FEATURES
-set(CMAKE_TOOLCHAIN_FILE $ENV{VCPKG_ROOT}/scripts/buildsystems/vcpkg.cmake
-        CACHE FILEPATH "Vcpkg toolchain file")
+## force so that gradle doesn't stomp vcpkg toolchain with the android toolchain
+set(CMAKE_TOOLCHAIN_FILE $ENV{VCPKG_ROOT}/scripts/buildsystems/vcpkg.cmake CACHE FILEPATH "Vcpkg toolchain file" FORCE)
+
+if (DEFINED ANDROID_ABI AND NOT DEFINED VCPKG_CHAINLOAD_TOOLCHAIN_FILE)
+    # CmakePresets.json doesn't allow us to use cmake vars in values, so set it here
+    set(VCPKG_CHAINLOAD_TOOLCHAIN_FILE $ENV{ANDROID_NDK_HOME}/build/cmake/android.toolchain.cmake)
+endif()
 
 project(nakama-sdk LANGUAGES CXX)
 
@@ -205,6 +210,8 @@ endif()
 
 if (HTTP_IMPL STREQUAL "cpprestsdk")
     add_subdirectory(impl/httpCppRest EXCLUDE_FROM_ALL)
+elseif(HTTP_IMPL STREQUAL "curl")
+    add_subdirectory(impl/httpCurl EXCLUDE_FROM_ALL)
 endif()
 
 add_library(nakama-ws-impl INTERFACE)
@@ -225,6 +232,41 @@ if(HTTP_IMPL STREQUAL "libhttpclient")
     add_subdirectory(impl/httpLibHttpClient EXCLUDE_FROM_ALL)
 endif()
 
+if (ANDROID AND (HTTP_IMPL STREQUAL "curl" OR WS_IMPL STREQUAL "wslay"))
+    add_subdirectory(impl/android)
+    set(CREATE_JAR TRUE) # we need the code for accessing native Android CA store.
+
+    if (HTTP_IMPL STREQUAL "curl")
+        target_link_libraries(nakama-impl-http-libcurl PUBLIC android-ca)
+    endif()
+
+    if (WS_IMPL STREQUAL "wslay")
+        target_link_libraries(nakama-impl-ws-wslay INTERFACE android-ca)
+    endif()
+
+    list(APPEND NAKAMA_SDK_DEPS $<TARGET_OBJECTS:android-ca>)
+else()
+    set(CREATE_JAR FALSE)
+endif()
+
+if (CREATE_JAR)
+    message("-- Configured to build Java code with Gradle.")
+
+    set(LIBNAKAMA_AAR "${CMAKE_SOURCE_DIR}/android/app/build/outputs/aar/libnakama-sdk.aar")
+    # TODO it's very odd that add_custom_command did not seem to trigger, so we use add_custom_target
+    add_custom_target(
+        nakama-aar ALL
+        COMMAND ./gradlew assemble
+        BYPRODUCTS ${LIBNAKAMA_AAR}
+        WORKING_DIRECTORY ${CMAKE_SOURCE_DIR}/android
+        VERBATIM
+        USES_TERMINAL
+        DEPENDS ${CMAKE_SOURCE_DIR}/test/android/src/main/java/com/heroiclabs/nakamatest/MainActivity.java
+    )
+
+    install(FILES ${LIBNAKAMA_AAR} DESTINATION ${CMAKE_INSTALL_LIBDIR})
+endif()
+
 find_package(optional-lite CONFIG REQUIRED)
 # SDK API
 add_subdirectory(interface)
@@ -245,7 +287,6 @@ list(APPEND NAKAMA_SDK_DEPS
     $<TARGET_OBJECTS:nakama-sdk-client-factory>
     $<TARGET_OBJECTS:nakama-sdk-rtclient-factory>
 
-
     # Xcode generator doesn't produce library for a target with no "own" files
     # https://gitlab.kitware.com/cmake/cmake/-/issues/23688
     ${DUMMY_CPP}
@@ -258,6 +299,7 @@ if (BUILD_GRPC_CLIENT)
     list(APPEND NAKAMA_SDK_DEPS $<TARGET_OBJECTS:nakama-sdk-core-grpc>)
 endif()
 
+## TODO this can be massively simplified
 if (WITH_LIBHTTPCLIENT_WS)
     target_compile_definitions(nakama-sdk-core-rt PUBLIC BUILD_WEBSOCKET_LIBHTTPCLIENT)
     target_compile_definitions(nakama-sdk-core-common PUBLIC BUILD_WEBSOCKET_LIBHTTPCLIENT)
@@ -296,7 +338,7 @@ set_target_properties(nakama-sdk PROPERTIES
         MACOSX_FRAMEWORK_SHORT_VERSION_STRING ${LIBNAKAMA_VERSION}
         VERSION ${LIBNAKAMA_VERSION}
         SOVERSION ${LIBNAKAMA_SOVERSION}
-    )
+)
 
 add_library(nakama::sdk ALIAS nakama-sdk)
 target_link_libraries(nakama-sdk

CMakePresets.json

@@ -74,7 +74,7 @@
                 "CMAKE_OSX_ARCHITECTURES": "arm64",
                 "WITH_LIBHTTPCLIENT_HTTP": "ON",
                 "BUILD_WSLAY": "ON",
-                "BUILD_CURL": "ON",
+                "BUILD_CURL_IO": "ON",
                 "VCPKG_MANIFEST_FEATURES": "wslay;curl"
             },
             "condition": {
@@ -125,7 +125,7 @@
                 "VCPKG_TARGET_TRIPLET": "arm64-ios-heroic",
                 "CMAKE_SYSTEM_NAME": "iOS",
                 "BUILD_WSLAY": "ON",
-                "BUILD_CURL": "ON"
+                "BUILD_CURL_IO": "ON"
             },
             "installDir": "out/ios-arm64"
         },
@@ -175,34 +175,18 @@
                 "ANDROID_ARM_NEON": "ON",
                 "ANDROID_STL": "c++_shared",
                 "ANDROID_PLATFORM": "android-21",
+                "BUILD_CURL_HTTP": "ON",
+                "BUILD_WSLAY": "ON",
+                "BUILD_CURL_IO": "ON",
                 "CMAKE_SYSTEM_NAME": "Android",
-                "VCPKG_MANIFEST_FEATURES": "cpprestsdk",
-                "WITH_CPPRESTSDK": "ON"
+                "VCPKG_MANIFEST_FEATURES": "curl;wslay"
             },
             "condition": {
                 "type": "equals",
                 "lhs": "${hostSystemName}",
                 "rhs": "Darwin"
             }
         },
-        {
-            "name": "android-armeabi-v7a-host_osx_x64",
-            "inherits": [
-                "android-default"
-            ],
-            "generator": "Ninja Multi-Config",
-            "cacheVariables": {
-                "VCPKG_HOST_TRIPLET": "x64-osx-heroic",
-                "VCPKG_TARGET_TRIPLET": "arm-neon-android-heroic",
-                "ANDROID_ABI": "armeabi-v7a"
-            },
-            "condition": {
-                "type": "equals",
-                "lhs": "${hostSystemName}",
-                "rhs": "Darwin"
-            },
-            "installDir": "out/android-armeabi-v7a"
-        },
         {
             "name": "android-arm64-v8a-host_osx_x64",
             "inherits": [
@@ -240,7 +224,7 @@
             "installDir": "out/android-x64"
         },
         {
-            "name": "android-armeabi-v7a-host_osx_arm64",
+            "name": "android-arm64-v8a-host_osx_arm64",
             "inherits": [
                 "android-default"
             ],
@@ -257,24 +241,6 @@
             },
             "installDir": "out/android-armeabi-v7a"
         },
-        {
-            "name": "android-arm64-v8a-host_arm64",
-            "inherits": [
-                "android-default"
-            ],
-            "generator": "Ninja Multi-Config",
-            "cacheVariables": {
-                "VCPKG_HOST_TRIPLET": "arm64-osx-heroic",
-                "VCPKG_TARGET_TRIPLET": "arm64-android-heroic",
-                "ANDROID_ABI": "arm64-v8a"
-            },
-            "condition": {
-                "type": "equals",
-                "lhs": "${hostSystemName}",
-                "rhs": "Darwin"
-            },
-            "installDir": "out/android-arm64-v8a"
-        },
         {
             "name": "android-x64-host_osx_arm64",
             "inherits": [
@@ -304,7 +270,7 @@
                 "VCPKG_TARGET_TRIPLET": "x64-linux-heroic",
                 "WITH_LIBHTTPCLIENT_HTTP": "ON",
                 "BUILD_WSLAY": "ON",
-                "BUILD_CURL": "ON",
+                "BUILD_CURL_IO": "ON",
                 "VCPKG_MANIFEST_FEATURES": "curl;wslay"
             },
             "condition": {

README.md

@@ -198,6 +198,18 @@ You can change ping period on server - `ping_period_ms` parameter:
 
 https://heroiclabs.com/docs/install-configuration/#socket
 
+#### Android
+
+To use our native C++ library in your Android application, you will need to include an additional .aar file that we ship for SSL support.
+
+For example, in Gradle:
+
+```
+implementation files("<path/to/libnakama-sdk.aar>")
+```
+
+Then you will need to load our native library from Java by calling `System.loadLibrary("nakama-sdk")` when your activity is created.
+
 # How to build
 
 ## Prerequisite

android/app/build.gradle

@@ -0,0 +1,28 @@
+plugins {
+    id 'com.android.library' version '7.4.0' apply true
+}
+
+repositories {
+    google()
+    mavenCentral()
+}
+
+android {
+    compileSdkVersion 32
+    defaultConfig {
+        minSdkVersion 21
+        targetSdkVersion 32
+    }
+
+    libraryVariants.all {
+        variant ->
+        variant.outputs.all {
+            outputFileName = "libnakama-sdk.aar"
+        }
+    }
+}
+
+dependencies {
+    implementation 'androidx.appcompat:appcompat:1.5.1'
+    implementation 'org.bouncycastle:bcpkix-jdk15on:1.66'
+}

android/app/src/main/AndroidManifest.xml

@@ -0,0 +1,9 @@
+<?xml version="1.0" encoding="utf-8"?>
+<manifest xmlns:android="http://schemas.android.com/apk/res/android"
+    package="com.heroiclabs.nakamasdk"
+    android:versionCode="1"
+    android:versionName="1.0">
+
+    <uses-permission android:name="android.permission.ACCESS_NETWORK_STATE"/>
+    <application/>
+</manifest>

android/app/src/main/java/com/heroiclabs/nakamasdk/AndroidCA.java

@@ -0,0 +1,58 @@
+/*
+ * Copyright 2023 The Nakama Authors
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     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.
+ */
+
+package com.heroiclabs.nakamasdk;
+
+import androidx.annotation.Keep;
+import java.io.ByteArrayOutputStream;
+import java.io.OutputStreamWriter;
+import java.io.Writer;
+import java.security.KeyStore;
+import java.security.cert.Certificate;
+import java.security.cert.CertificateException;
+import java.security.cert.X509Certificate;
+import java.util.Base64;
+import java.util.Enumeration;
+
+public class AndroidCA {
+
+    @Keep
+    public static byte[] getCaCertificates() {
+        try {
+            KeyStore keyStore = KeyStore.getInstance("AndroidCAStore");
+            keyStore.load(null, null);
+            Enumeration<String> aliases = keyStore.aliases();
+
+            ByteArrayOutputStream outputStream = new ByteArrayOutputStream();
+            Writer writer = new OutputStreamWriter(outputStream);
+
+            while (aliases.hasMoreElements()) {
+                String alias = aliases.nextElement();
+                X509Certificate cert = (X509Certificate) keyStore.getCertificate(alias);
+
+                writer.write("-----BEGIN CERTIFICATE-----\n");
+                writer.write(Base64.getEncoder().encodeToString(cert.getEncoded()));
+                writer.write("\n-----END CERTIFICATE-----\n");
+            }
+
+            writer.flush();
+            return outputStream.toByteArray();
+        } catch (Exception e) {
+            e.printStackTrace();
+            return new byte[0];
+        }
+    }
+}

android/gradle.properties

@@ -0,0 +1,2 @@
+android.enableJetifier=true
+android.useAndroidX=true