Develop Reference

Bluetooth Pairing Without users' confirmation

Can I pair smartphone over Bluetooth without a need to confirm this in user interface, accept to pair this devices. I use android studio. I don't need to exchange data over them, I need just pairing without any action. And then safely pair with smartphone over Bluetooth without any user's action?

Yes and no, but you shouldn't anyway.
The only way to do this in Android is by using the BLUETOOTH_PRIVILEGED permission, which, as you can see, is only granted to apps in /system/priv-app/ or apps signed by the platform key of the device.
So unless you have root and can move your app to /system/priv-app/, you can't do what you want. Even if you can do this, however, don't. It's not a good user experience when someone installs an app, only for it to move itself to the system partition and start pairing without any notification.

Block single apk notifications via adb

I'm looking to change notifications settings for a single application remotely.
I've got the device enrolled into a MDM.
Android device running 6.01.
I can remotely deploy / update apps etc...
However, I want to disable notifications for this. I can't seem to find a hands off approach to doing this.
I'd have to break out of the end user lock down application.
Go to settings
apps
find app
notifications
block
restart device.
Is there a way I can remotely make this change?
Thanks in advance.

you might have more luck asking your MDM provider but there is no way to achieve this from the platform. This is not a requirement I have heard before, typically enterprise devices are configured to block all notifications or allow all. If you do not plan on using the application in question you could likely disable the entire app remotely but being able to disable notifications for that specific app remotely is not currently possible.

The MDM provider said it was an OS behavior and needs to be suppressed from the OS. I got it sorted by disabling them the manual way.

How to make only traffic from some APPs go through VPN in Android?

I want to build a VPN APP on Android basing VPN service. one special requirement of this VPN APP is it has a white list, only traffic come from APPs in this list will go to VPN server. All rest traffic go to what they used to go.
For example, I have a VPN server in USA, and I am in China. I want Facebook goes through VPN. but Youku goes to Youku's server directly.
My first problem here is how can determine some traffic come from which APP?
I know it's possible, because there an APP called no root firewall can block traffic per APP, which is also basing Android VPN service.
https://play.google.com/store/apps/details?id=app.greyshirts.firewall
I'm new to Android, can anybody tell me how to do this?
Thanks in advance!

Have a look at the addAllowedApplication() method, it accepts the packageName who's traffic should be allowed to go through VpnService.

Enable data connection on android system app

I'm trying to make a android system app (for me and friends), to let me control my android phone over my server.
Actually I've problem to enable/disable data connection. When I search, I found topic that said there is no possibility, or giving a no longer supported way (by using breach). This was exactly the same for GPS controle, but I found a way because my app is a system app.
So I want to know if someone know a way to enable and disable data connection without user consent on a system app. I didn't find anything on the api.
Thanks !

Building a native app to uniquely identify, track and lock a smartphone handset

I'm currently doing some research about my project, a smartphone tracking native application, and I have four questions. Links to any material I can read up will be greatly appreciated, and the most useful/comprehensive response will be accepted.
The primary target smartphones are the Android, Blackberry and iPhone models.
For starters I found out here Uniquely Identify an Android Handset that IMEI can be used to uniquely identify Androids but I think I once read that it can be faked. I don't know about the iPhone and Blackberry.
What's the most reliable way to uniquely identify the smartphone device, if any? Can MAC addresses work or is it possible to spoof that? Can IMEIs truly be faked?
Is it possible to "lock" the device with a custom error message remotely via its unique identification, once the device is reported as stolen? This lock state will remain on the phone even when disconnected from the network, until it is reconnected to the network and unlocked remotely once again.
Assuming such a remote phone lock is possible, can such be reversible by the thief? The native app will run in stealth mode so that it cannot be uninstalled.
Can a cross-platform solution work in this case, or will I have to develop various native apps per platform?
EDIT:
Some more context. As Till rightly said, Apple's "Find my Phone" does this exact thing already (I am just finding out about it, but it looks like a perfect fit already). The user who is choosing to install the app is informed that the phone will be uniquely identified if they do install the app. As for locking the device, "Find my Phone" does it (I gather). Now I need to know how that might be possible on the two other platforms.

With regards the iPhone side of things:
You aren't allowed to uniquely identify the iPhone like that. Apple have just forbidden it unless you get the user's permission first. So if they refuse you permission, your app won't function and you'll need to find another way.
No, you can't do that.
See 2. Also you can't run an app in "stealth mode"
See 2.

Only the network operators can talk to the handsets on an IMEI level. The IMEI number IS the MAC address of GSM networks. However, you can't access that unless you have control of the network. Sure you can get the IMEI from the user, but you can't use that to locate the phone. On CDMA networks this address is called the MEID number.
But there are other ways:
You can get location data on either platform with the users' permission. This is the way you should think about developing your application. You'll want to assign a UUID to a user once they download and install your application on their phones. You can then have the phones report to a server every so often (heartbeat). As long as the phone is powered on and connected to a network, the user would be able to locate the phone.
You can also get the phones IP address on the network, among other things -- such as contacts, messages, files, cache data etc..
On Android it's pretty easy to implement this kind of functionality as a service that could would only be visible on the packages page. Further, if you have root access, you can write whatever kind of rootkit you want such that it hides itself from the system. Same with a jailbroken iPhone. I am not as knowledgeabe about iPhone services though.
Either way, the only cross platform compatibility you'd be able to exploit would be perhaps the way data is sent and received from the server. You could use some standard such as JSON to send and receive data (and hence the same server). Although, both platforms have JSON and Apache libraries, the other parts of the apps or services themselves will need to be completely and dependently developed for each platform (UI, Internal Content Handeling, Syscalls, Permissions, etc).
You can remotely lock, wipe, factory reset, etc. Android devices using the security and device administration Android system interface. This still requires the user to grant permission and it asks them an a more.. obnoxious.. way so that they know what exactly they are agreeing to when they give an app device administration permission. If you ever use an exchange server for business or school, it's likely you'll run into this.
I am unsure about remote iPhone device administration on a jailed system.
If you really want something that can't be removed lest you do a factory reset, you'll need to know a thing or two about Unix programming, and a lot about the operating systems that their respective SDK's don't (and probably shouldn't) tell you. You'll need to be comfortable poking around sources and even reverse engineering if called for. If you're still interested, you'll want to hang around the circles that work on custom phone firmware and software for the iPhone, and Android (and Blackberry). I would start with Android. It's probably the easiest since the sources for the AOSP are easily and legally available.