We use go-mobile to achieve this goal. This great tool allows us to generate bindings from a Go package that can be later invoked from Java / Kotlin (on Android) and ObjC / Swift (on iOS).
The package prifiMobile (found in the folder prifi-mobile) contains all the functions, methods and structs that we want to expose to Android and iOS using go-mobile.
If you want to expand this package, please be aware of the type restrictions of go-mobile.
Please check the official wiki for the installation.
Make sure that the target SDK tools are installed before calling gomobile init.
- Android: Android SDK and Android NDK are both required.
- iOS: Xcode is required
gomobile bind -target android github.com/lbarman/prifi/prifi-mobile produces an AAR (Android ARchive) file. The output is named '<package_name>.aar' by default, in our case, it's prifiMobile.aar. For more information, pleas check the official wiki.
Note: the generated library is big, thus it's not tracked by git.
Normally, the generated AAR can be directly used in any Android apps. Unfortunately in our case, there is one more step to do.
We know that PriFi uses ONet as a network framework, and ONet has an OS check at launch. Unfortunately, ONet.v2 (29 May 2018) currently doesn't support Android, which results an instant crash on Android.
We need to modify the system checking mechanism in gopkg.in/dedis/onet.v2/cfgpath/cfgpath.go.
func GetConfigPath(appName string) string {
if len(appName) == 0 {
log.Panic("appName cannot be empty")
}
home := os.Getenv("HOME")
if home == "" {
u, err := user.Current()
if err != nil {
log.Warn("Could not find the home directory. Switching back to current dir.")
return getCurrentDir(appName)
}
home = u.HomeDir
}
switch runtime.GOOS {
case "darwin":
return path.Join(home, "Library", "Application Support", appName)
case "windows":
return path.Join(os.Getenv("APPDATA"), appName)
case "linux", "freebsd":
xdg := os.Getenv("XDG_CONFIG_HOME")
if xdg != "" {
return path.Join(xdg, appName)
}
return path.Join(home, ".config", appName)
case "android":
return path.Join("/data/data/ch.epfl.prifiproxy/files", appName, "config")
default:
return getCurrentDir(appName)
}
}
func GetDataPath(appName string) string {
switch runtime.GOOS {
case "linux", "freebsd":
xdg := os.Getenv("XDG_DATA_HOME")
if xdg != "" {
return path.Join(xdg, appName)
}
return path.Join(os.Getenv("HOME"), ".local", "share", appName)
case "android":
return path.Join("/data/data/ch.epfl.prifiproxy/files", appName, "data")
default:
p := GetConfigPath(appName)
return path.Join(p, "data")
}
}
Adding case "android": p = path.Join("/data/data/ch.epfl.prifiproxy/files", ...) will solve the problem for our PriFi demo app (package name: ch.epfl.prifiproxy). If you want to generate an AAR for your own app, please put the corresponding package name instead of ch.epfl.prifiproxy.
We haven't tested on iOS yet. (25 April 2018).
If you use our demo app prifi-mobile-apps/android/PrifiProxy, there is nothing to configure, just put the AAR into .../PrifiProxy/app/libs and resync the project.
If you want to use the generated AAR in your own app, please put the file in the same location YourApp/app/libs and include the following lines into the gradle scripts.
Project-level build.gradle
Include
flatDir {
dirs 'libs'
}
into
allprojects {
repositories {
...
}
}
App-level build.gradle
Include
implementation(name: 'prifiMobile', ext: 'aar')
into
dependencies{
...
}
Note 1: Old gradle versions uses the keyword compile instead of implementation.
Note 2: If you want to replace AAR with a newer version, please delete the old one and sync gradle, then put the new one in and resync gradle.
The steps described above are complicated, so we provide the AAR and the APK of our demo app that we are currently using.
prifiMobile.aar (7 June 2018)
PrifiProxy.apk (7 June 2018)