Develop Reference

iccOpenLogicalChannel returns STATUS_NO_SUCH_ELEMENT on Javacard Applet

I have an applet (taken from this HelloSTK2 repo) I've compiled and installed on a SysmoISIM-SJA2 card and I've lightly modified it to respond to a SELECT APDU. The modification looks like this:
public void process(APDU arg0) throws ISOException {
showHello();
}
private void showHello() {
ProactiveHandler proHdlr = ProactiveHandler.getTheHandler();
proHdlr.initDisplayText((byte)0, DCS_8_BIT_DATA, welcomeMsg, (short)0,
(short)(welcomeMsg.length));
proHdlr.send();
return;
}
All I did was move the existing showHello() function to the function that handles APDUs. It's my understanding from the Javacard documentation that the process() function should run and then return a status word of 9000, or an error code if applicable.
To SELECT the file I have an Android application I've written that uses iccOpenLogicalChannel and takes the AID as an argument. Using GlobalPlatformPro I can see that the applet is installed properly on the UICC and that it is listed as SELECTABLE, however when I run my Android application I get a STATUS_NO_SUCH_ELEMENT response which according to the iccOpenLogicalChannelResponse source means the AID is not found on the UICC.
The code for the Android app is very simple and looks like this:
val inputView: EditText = findViewById<EditText>(R.id.AID_INPUT)
val input: String = inputView.text.toString()
val ch = mTelephonyManager.iccOpenLogicalChannel(input)
Toast.makeText(this, ch.toString(), Toast.LENGTH_LONG).show()
mTelephonyManager.iccCloseLogicalChannel(ch.channel)
and the output of listing the applets on the card looks like this (truncated):
AID: d07002ca44, State: 01, Privs: 00
Instance AID: d07002ca44900102
I've tried both d07002ca44 and d07002ca44900102 and get the same response for both AIDs.
My question then: what steps do I need to take to ensure this applet is able to be selected by my Android application?
Worth noting probably that my Android app does have carrier privileges and I'm able to send APDUs to other applications such as the USIM and ISIM applets.

How to get a full android app UID programmatically?

Edit 10 Apr 2020
I may have misnamed what we are looking for. It may actually be the linux user name of the installed app, rather than its UID. So how should we get that programmatically?
Original question below
When we use adb shell ps even on a non rooted android device, it returns process info where the UID comes in the form u0_xxxx where x represents some arbitrary digits in hex (except for system/root processes).
For example
u0_a464 31481 894 5015336 69200 0 0 S com.example.app_uid_checker
In this example app_uid_checker is my app in user space. When trying to obtain the UID programmatically, though, I get 10464 (the decimal representation of a464), and without the u0 prefix.
I tried
package manager's getApplicationInfo()
activity manager's getAllRunningProcess()
android.os.Process.myUid()
(following suggestions in this post on SO. They all return 10464. How can I get the "full" UID? (for want of a better term, I'm not sure what the u0_a464 version of the UID should be called, as compared to the 10464 version)).
Even if we can programmatically use adb shell ps I think it may not be a good way, as adb needs developer mode to be enabled.

You need to use the geteuid(2) and getpwuid(3) to retrieve the data, as the JVM does not expose it.
extern "C" JNIEXPORT jstring JNICALL Java_com_example_GetUser_getUser(JNIEnv* env) {
uid_t uid = geteuid();
struct passwd *user;
if (uid == -1)
return NULL;
user = getpwuid(uid);
return env->NewStringUTF(user->pw_name);
}
Full working project: https://gitlab.com/hackintosh5/getuser

Android 5 - Redirect stdout to logcat

I am trying to run some GMock/GTest tests on Android. These all run fine, but there's no output, as GMock logs to stdout.
I've tried the following with no luck (likely because it's for the Dalvik VM, and they've done away with that in Android 5):
$ adb shell stop
$ adb shell setprop log.redirect-stdio true
$ adb shell start
When log.redirect-stdio is set to true, there is still no output from stdio to logcat.
I've also tried custom several streambuf implementations with std::cout.rdbuf to try to direct stdout to logcat with __android_log_print, but none of these have printed anything to logcat.
Has anyone successfully managed to redirect stdout to logcat in Android 5?
I can add more details (such as streambuf implementations I've tried) if needed.

This isn't really a solution to the problem of redirecting stdout to logcat, but I'm suggesting it as a workaround in case it helps someone.
You can redirect stdout to a file instead:
freopen("/data/data/com.your.package/files/out.txt", "w", stdout);
... // Call GMock which prints to the file instead
fclose(stdout)
We can then cat the file to see the logged test results. Sadly Android doesn't have tail so the logging isn't nicely available in real time. (Unless you're good at spamming cat)

Do it with the old Java way: (but I am using kotlin, can anyone suggest a cleaner version?)
documentation: System.setOut()
import java.io.OutputStream
import java.io.PrintStream
private const val TAG = "MyActivity"
class LogcatOutputStream: OutputStream(){
private var line_buffer: StringBuilder = StringBuilder()
override fun write(b: Int){
when(b){
'\n'.toInt() -> {
Log.i(TAG, line_buffer.toString())
line_buffer.setLength(0)
}
else -> line_buffer.append(b.toChar())
}
}
}
// put this somewhere in the code, like onCreate() as shown
class MainActivity: Activity(){
override fun onCreate(savedInstanceState: Bundle?){
// some other code
PrintStream(LoggerOutputStream()).let{
System.setOut(it)
System.setErr(it)
}
// some other code
}
}
// result:
println("Hello World") // which is effectively System.out.println in Java
// with have the below output in logcat
I/MyActivity(<pid>): Hello World
// as a reminder, you can filter logcat by tags
adb logcat MyActivity:D
// to only show logs tagged with 'MyActivity' (same value as 'TAG' above)

Storing android adb shell screencap as variable

Making an app at the moment for my personal use (rooted) and it requires getting certain pixels colors from the screen. I was trying to accomplish this through the Runtime.
Process p = Runtime.getRuntime().exec("screencap");
p.waitFor();
InputStream is = p.getInputStream()
BitmapFactory.decodeStream(is);
and I get factory returned null.
but if I dump the process to my sd card through adb -d shell screencap /sdcard/ss.dump and access it from my app
BitmapFactory.decodeFile("/sdcard/ss.dump");
all goes well.
So it there anyway to dump the stream straight into BitmapFactory within my app?
Thanks SO and please excuse the generally laziness/shortcuts of the example code.

This might help if not too far off your intended path. (I think you are using node / javascript). I spawned the ADB.EXE command producing a stream (and being 'jailed' on Windows the program must transform the stream to account for linefeed ending differences. So with that, I have working the following:
exports.capture = function(filename) {
// you'll need to map your requirement (decodeStream) instead
// of streaming to a file
var strm = fs.createWriteStream(path);
var cv = new Convert();
cv.pipe(strm);
var capture = spawn(cmd, args);
capture.stdout.on('data', function(data) {
cv.write(data);
});
capture.stdout.on('exit', function(data) {
cv.end();
});
}
To explain the process, spawn is running the ADB command, on windows, CR-LF are inserted (being a PNG stream), and stream is chunked / piped through a fs-transformation. Others on the web have described the process as adb.exe shell screencap -p | sed 's/\r$//' > output.file. And it does work. To be clear the conversion is CR-CR-LF => LF for us window jailed birds. And if you don't want to implement a SED and not use javascript regular expressions converting binary->strings->binary, you may follow my path. There is probably a simpler way, I just don't know what it is...
So, Convert() is an object with methods that converts the byte stream on the fly.
See the codewind blog link is: http://codewinds.com/blog/2013-08-20-nodejs-transform-streams.html to build your convert.

When using screencap from inside an app you must use su, i.e. root. When you do this via adb it runs under a different user id, which has more permissions than a normal Android app.
There are several examples how to use screencap, e.g. here.

How to launch android app through python

I want to run any app (say Settings) after rebooting tablet. Can I use os.system or do I have to use other methods.
import os,time
for i in range(0,3):
os.system("adb reboot")
time.sleep(60)

Yes, you can use os.system to execute ADB commands. If you want to validate the command executed successfully, take a look at the check_output(...) function which is apart of the subprocess library. This code snipet is how I choose to implement the check_output function. For the full code look here.
def _run_command(self, cmd):
"""
Execute an adb command via the subprocess module. If the process exits with
a exit status of zero, the output is encapsulated into a ADBCommandResult and
returned. Otherwise, an ADBExecutionError is thrown.
"""
try:
output = check_output(cmd, stderr=subprocess.STDOUT)
return ADBCommandResult(0,output)
except CalledProcessError as e:
raise ADBProcessError(e.cmd, e.returncode, e.output)
To launch an application you can use the command am start -n yourpackagename/.activityname. To launch the Settings App, run adb shell am start -n com.android.settings/com.android.settings.Settings. This stackoverflow question shows you in detail the options you can use to start the application via a command line intent.
Other tips:
I created an ADB wrapper written in python along with a few other python utilities that may aid in what you are trying to accomplish. For example, instead of calling time.sleep(60) to wait for the reboot, you use adb to poll the status of the property sys.boot_completed and once the property is set the device has finished booting and you can launch any application. Below is a reference implementation you can use.
def wait_boot_complete(self, encryption='off'):
"""
When data at rest encryption is turned on, there needs to be a waiting period
during boot up for the user to enter the DAR password. This function will wait
till the password has been entered and the phone has finished booting up.
OR
Wait for the BOOT_COMPLETED intent to be broadcast by check the system
property 'sys.boot_completed'. A ADBProcessError is thrown if there is an
error communicating with the device.
This method assumes the phone will eventually reach the boot completed state.
A check is needed to see if the output length is zero because the property
is not initialized with a 0 value. It is created once the intent is broadcast.
"""
if encryption is 'on':
decrypted = None
target = 'trigger_restart_framework'
print 'waiting for framework restart'
while decrypted is None:
status = self.adb.adb_shell(self.serial, "getprop vold.decrypt")
if status.output.strip() == 'trigger_restart_framework':
decrypted = 'true'
#Wait for boot to complete. The boot completed intent is broadcast before
#boot is actually completed when encryption is enabled. So 'key' off the
#animation.
status = self.adb.adb_shell(self.serial, "getprop init.svc.bootanim").output.strip()
print 'wait for animation to start'
while status == 'stopped':
status = self.adb.adb_shell(self.serial, "getprop init.svc.bootanim").output.strip()
status = self.adb.adb_shell(self.serial, "getprop init.svc.bootanim").output.strip()
print 'waiting for animation to finish'
while status == 'running':
status = self.adb.adb_shell(self.serial, "getprop init.svc.bootanim").output.strip()
else:
boot = False
while(not boot):
self.adb.adb_wait_for_device(self.serial)
res = self.adb.adb_shell(self.serial, "getprop sys.boot_completed")
if len(res.output.strip()) != 0 and int(res.output.strip()) is 1:
boot = True