Hey guys,
I'm in the very very early stages of my masters work and I was toying around with the idea of using an Android tablet for part of it. I want to ask you devs what can be done when modifying the Android OS itself specifically in terms of a few things.
1. Logins - I would like to implement a classic user/password combination with levels of access for user, administrator, and some sort of superuser.
2. Restriction of User account - I would like to lock the user into one particular application. It must be relaunched when the device is booted and if the application crashes (hopefully not!) it must be restarted. Additionally, no market access, web access, etc.
3. Remote management if possible
4. Data encryption if possible
5. Prevent anything from being introduced from USB ports, SD slot, etc if unwanted.
I guess this brings me around to - is Android even the most suitable platform for such an endeavor. I'm not sure, to be honest, but I would love to get into development myself and this seems like a great way to learn. This is all just one part of a much larger project that I don't want to discuss just yet so sorry for being lax on details.
Thanks guys!
Android runs a virtual machine system called dalvik, in which each application gets it's own insuranceof the machine. It's implemented in such a way that each application gets assigned a user id, which unfortunately for you means each app is a different user, at least to the system. That's going to be a major wrench in the multi user plans. taking that into consideration, to have the same level of control over your tablet you'd have to give even the most basic user level "root" access or else the apps will start crapping their collective pants. As far as unwanted usb, there are a few apps that implement this functionality freely available through the market. Same with remote management. What I haven't seen yet is total encryption and I don't know enough about it to say it's possible or not. Seems feasible though.
My advice: write a custom login screen widget and then bake all these features into a pretty rom.
MOD EDIT: Thread closed by OP's request.
If you have used reker's proxy, you will notice the "by @reker" entry on top of the list with search results. If we could do the same with the SamWP8 tool (and link his app to a similar app page), maybe we could bypass the interop unlock requirement (the error you receive if you try to sideload a app with interop capabilities on a non-interop unlocked phone) because apps installed in the store don't get this check (as compu829 demonstrated by saying the original Microsoft youtube app contained the ID_CAP_MEDIALIB_PHOTO_FULL entry in the WMAppManifest.xml, and how could you install this app on phones without having an interop-unlock, exactly : the app was installed through the store).
Correct me if I'm wrong, I'm still learning how the WP OS is build and how it functions.
To admins, I can't post this in the Windows Phone 8 Development and Hacking thread because I don't have the required 10 posts yet.
Seems like a feasible idea, I'll take a look on how the store works but I think the XAP's still need to be signed by a trusted root to this works.
I'll post any updates here as I can't post on dev section x.x
This idea is older than WP8, and it doesn't work. First of all, the apps themselves (as opposed to the data about them) are delivered over an encrypted channel that uses certificate pinning; we can't intercept or modify it. Second, the Store will only install Microsoft-signed (and probably only DRMed) apps. Unsigned apps failed to install through this channel back on WP7. Third, even if we could install the apps this way, hey would still be unsigned. The OS would thus treat them as developer apps. Developer apps on phones where the MaxUnsignedApp registry value is less than 300 are limited to the standard third-party app capabilities, meaning no INTEROPSERVICES or similar.
By all means, go ahead and poke at it - WP8 has surprised me before with weaknesses it has relative to WP7 - but don't expect this to work even if you get past the first issue (which *does* exist on WP8).
Did someone contact reker? We need to figure out how he did this. I can't tell if he succeeded into linking an app to the custom app page because when I click install, I get an error message : "This app is not available for your region", maybe I need to change my region to China and try again.
@GoodDayToDie : Won't the phone be tricked by the store installation, thinking it's an encrypted app? Does it matter whether the app is encrypted or not if someone manages to link an app to a custom app page, because Windows Phone app weren't always encrypted to my recollection (this may predate the WP8 era, if so we're screwed ). And if it matters, can we encrypt the app ourselves by using a encryption method like AES, SHA, MD5, ... ? Unlikely hypothesis, but if someone would succeed in doing all this, could the SamWP8 tool be used to increase the HKEY_Local_Machine\Software\Microsoft\DeviceReg\Install MaxUnsignedApp value beyond 300 to unlock interop capabilities? Are the EnableAllSideloading.xap and Bootstapper.xap also usable on other WP than Samsung or do they need to be recoded to work on WP of other manufacturers?
EnableAllSideloading.xap and Bootstapper.xap depends on Samsung diagnosis tool and it's RPC server that runs on LocalSystem account that has "unlimited" registry access, it's not available on other manufacturers.
Tonight I will start my experiments on it.
greenboxal said:
EnableAllSideloading.xap and Bootstapper.xap depends on Samsung diagnosis tool and it's RPC server that runs on LocalSystem account that has "unlimited" registry access, it's not available on other manufacturers.
Tonight I will start my experiments on it.
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Click to collapse
I was wondering how you could flash the bootloader of Android on the Ativ S as the Secure Boot made by Qualcomm is locked by a blown fuse (it's a hardware issue, not only a software issue you must deal with).
bruce142 said:
I was wondering how you could flash the bootloader of Android on the Ativ S as the Secure Boot made by Qualcomm is locked by a blown fuse (it's a hardware issue, not only a software issue you must deal with).
Click to expand...
Click to collapse
SecureBoot checks signature of the bootloader by a known public key, the case is that Samsumg uses the *same* key for android and wp8 bootloaders.
greenboxal said:
SecureBoot checks signature of the bootloader by a known public key, the case is that Samsumg uses the *same* key for android and wp8 bootloaders.
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Click to collapse
If this checks out, what does it mean, could we flash android on the Ativ S? Or could you even make a dual-boot scenario possible? Great find by the way, :good:.
bruce142 said:
If this checks out, what does it mean, could we flash android on the Ativ S? Or could you even make a dual-boot scenario possible? Great find by the way, :good:.
Click to expand...
Click to collapse
Yes, it's the same hardware as SGS3 Snapdragon 4 version. But let go back to the topic, if you have some question about it send me a PM or post on my R&D thread
greenboxal said:
Yes, it's the same hardware as SGS3 Snapdragon 4 version. But let go back to the topic, if you have some question about it send me a PM or post on my R&D thread
Click to expand...
Click to collapse
I can't post yet in your R&D thread because I don't have the met the 10 post requirement yet.
Edit : I can install reker's "by @ reker" app when changing the region to China, and this is interesting (pasted directly from his WMAppManifest.xml) :
<?xml version="1.0" encoding="UTF-8"?>
-<Deployment AppPlatformVersion="8.0" xmlns="http://schemas.microsoft.com/windowsphone/2012/deployment">
<DefaultLanguage xmlns="" code="zh-CN"/>
-<Languages xmlns="">
<Language code="zh-Hans"/>
</Languages>
-<App xmlns="" PublisherId="{9b1d1b5b-f206-4b27-a139-89659591061b}" IsBeta="false" PublisherID="{b259af64-2f7d-4a89-983f-836325480629}" Publisher="智机网_WPXAP" Description="智机市场官方版" Author="智机网_WPXAP" Genre="apps.normal" Version="2.0.0.0" RuntimeType="Silverlight" Title="智机市场" ProductID="{59bd999b-496e-4e05-afce-94b67ba6e862}">
<IconPath IsResource="false" IsRelative="true">Assets\ApplicationIcon.png</IconPath>
-<Capabilities>
<Capability Name="ID_CAP_IDENTITY_DEVICE"/>
<Capability Name="ID_CAP_IDENTITY_USER"/>
<Capability Name="ID_CAP_NETWORKING"/>
<Capability Name="ID_CAP_PUSH_NOTIFICATION"/>
<Capability Name="ID_CAP_SENSORS"/>
<Capability Name="ID_CAP_WEBBROWSERCOMPONENT"/>
<Capability Name="ID_CAP_APPOINTMENTS"/>
</Capabilities>
-<Tasks>
<DefaultTask Name="_default" ActivationPolicy="Resume" NavigationPage="MainPage.xaml"/>
</Tasks>
-<Tokens>
-<PrimaryToken TaskName="_default" TokenID="WpXapToken">
-<TemplateFlip>
<SmallImageURI IsResource="false" IsRelative="true">Assets\Tiles\FlipCycleTileSmall.png</SmallImageURI>
<Count>0</Count>
<BackgroundImageURI IsResource="false" IsRelative="true">Assets\Tiles\FlipCycleTileMedium.png</BackgroundImageURI>
<Title/>
<BackContent/>
<BackBackgroundImageURI/>
<BackTitle/>
<DeviceLockImageURI/>
<HasLarge/>
</TemplateFlip>
</PrimaryToken>
</Tokens>
-<Extensions>
<Protocol Name="wpxap" TaskID="_default" NavUriFragment="encodedLaunchUri=%s"/>
</Extensions>
-<ScreenResolutions>
<ScreenResolution Name="ID_RESOLUTION_WVGA"/>
<ScreenResolution Name="ID_RESOLUTION_WXGA"/>
<ScreenResolution Name="ID_RESOLUTION_HD720P"/>
</ScreenResolutions>
</App>
</Deployment>
@bruce142: The store may or may not care about the DRM - that was in place by the time WP8 came out, but WP7 didn't have it for a long time - but it absolutely cares about the signatures. More accurately, actually, the XAP install code (which the store invokes) cares about the signatures. There's no "tricking" it; the signature is quite plainly there, or it's not. You don't exactly have to look hard to find it. The app launch code *also* cares about signatures. Non-sideloaded apps won't have ID_CAP_DEVELOPERUNLOCK, which is a special capability automatically added to sideloaded apps to allow them to launch even though they don't have signatures. Without that capability (or rather, without the SID which the token of an app with that capability gets at chamber creation), the kernel will refuse to load the unsigned executable binaries.
GoodDayToDie said:
@bruce142: The store may or may not care about the DRM - that was in place by the time WP8 came out, but WP7 didn't have it for a long time - but it absolutely cares about the signatures. More accurately, actually, the XAP install code (which the store invokes) cares about the signatures. There's no "tricking" it; the signature is quite plainly there, or it's not. You don't exactly have to look hard to find it. The app launch code *also* cares about signatures. Non-sideloaded apps won't have ID_CAP_DEVELOPERUNLOCK, which is a special capability automatically added to sideloaded apps to allow them to launch even though they don't have signatures. Without that capability (or rather, without the SID which the token of an app with that capability gets at chamber creation), the kernel will refuse to load the unsigned executable binaries.
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Click to collapse
I understand, the app has to be signed before it can be uploaded to the store, but does the developer of an app not sign its app when he assembles it or does the store sign the app itself? I see no threshold here, as signing an app is not a problem, or is it? I still admire that reker managed to make an app page by using a proxy which isn't normally there and successfully linked an app to it, which I was able to download and it contained elevated capabilities, I thought the ID_CAP capabilities were all interop capabilities (correct me if I'm wrong). Could someone make the old version of the Samsung Diagnostic tool available this way which users with other WP than the Ativ S/Ativ S Neo might able to use to modify the MaxAppUnsigned value and unlock more capabilities, or is this impossible? If only we knew how reker did this, ...
bruce142 said:
I understand, the app has to be signed before it can be uploaded to the store, but does the developer of an app not sign its app when he assembles it or does the store sign the app itself? I see no threshold here, as signing an app is not a problem, or is it? I still admire that reker managed to make an app page by using a proxy which isn't normally there and successfully linked an app to it, which I was able to download and it contained elevated capabilities, I thought the ID_CAP capabilities were all interop capabilities (correct me if I'm wrong). Could someone make the old version of the Samsung Diagnostic tool available this way which users with other WP than the Ativ S/Ativ S Neo might able to use to modify the MaxAppUnsigned value and unlock more capabilities, or is this impossible? If only we knew how reker did this, ...
Click to expand...
Click to collapse
ID_CAP's aren't all Interop capabilities, most of them are available for every app, and the ones you posted are, afaik, normal ones that don't need and Interop Unlock.
GoodDayToDie is right. His answer is very detail.
You may replace a xap with homebrew one in theory, but phone will never launch a store app without MS signature. Every single dll is signed by MS, and phone will check it.
Few questions and opinions:
The signature is used only for allowing the app to be installed on the device right?
Is the signature after added to the app a constant for the whole time or is it changing from time to time?
If the signature is used only for allowing an app to be installed, can we somehow make an virtual MS Server (Using FIddler for example), who can clone the real one and give us an offline signing of the app`s when installing them?
Can a signature be pulled off from an original installed app and the be put in to an another one?
cevi said:
Few questions and opinions:
The signature is used only for allowing the app to be installed on the device right?
Is the signature after added to the app a constant for the whole time or is it changing from time to time?
If the signature is used only for allowing an app to be installed, can we somehow make an virtual MS Server (Using FIddler for example), who can clone the real one and give us an offline signing of the app`s when installing them?
Can a signature be pulled off from an original installed app and the be put in to an another one?
Click to expand...
Click to collapse
The signature is checked when running the application, every PE image on the device should have a valid digital signature.
You don't seem to understand how it works, the signature is any kind of hash, let's say, SHA256, of the entire file. This signature is encrypted with the signee private key. If you change one single bit of the file, the hash will change, and so the signature will be invalid.
There are few ways to exploit this kind of security, like generating a hash collision or breaking the private key, both would take million of years.
I do really don't understand the whole process I was just giving some noob suggestions.
It's strange for me that after the app is installed it doesn't require an active network to start.So I am wondering if it could be possible to trick the app to start somehow?
Sent from my Windows Phone 8S by HTC using Tapatalk
While suggestions are always welcome, you really should read up on digital signatures and how they work. @greenboxal's explanation seems like it might have gone over your head a bit... The fact that you didn't understand about ID_CAP_* also means you've probably never looked at WP development, or even looked at the manifest of a WP app, either; you may want to do some of that. Until you do so, it would be only by the sheerest crazy luck that you managed to hit on a solution, because you don't even know what you're actually trying to accomplish!
For example, it's pretty obvious why there's no need for a network connection to start an app, once it's installed. There's a license on WP apps, which is checked when the app is installed (requires Internet access) and is then valid for some time (never checked how long exactly, probably years though). The signatures are different. When the app is installed, the signing certificate (which contains the public key, but not the private key, of the keypair used to sign the app) is extracted from the app and checked to see whether it is trusted by Microsoft (the phone has Microsoft's certificates embedded in the OS; it doesn't need a network connection for this). When you try to launch the app, it checks to see whether the signatures on each binary (which are, as greenboxal mentioned, created by taking the cryptographically secure hash of the binary and then applying something like encryption to it using the private key) are valid (it applies the public key to the signature to get the signing hash back, and checks whether that hash still matches). We (developers) can't fake store signatures ourselves, because we don't have Microsoft's private keys. Therefore the phone wouldn't trust our signatures (make sure you read up on the concept of a "chain of trust" and the concepts of public key cryptography and public key infrastructure in general too) and would refuse to load the binaries. The process of verifying signatures is just a bunch of math once you've already got the public keys, and those are, as I said, extracted from the app at install (for individual apps) and stored in WP8 itself (for the Store-wide signing key); no need to access the network.
Thanks guys for clearing this up for me.I know that it`s not that simple as i say.Anyway, just keep up the good work.We the Noobs depend from you.
If you are not those who you really are i personally know that i will never buy a Windows Phone again.You are the reason for the MS`s profit.
Sorry again for jumping in into this "battle".
This thread is becoming way out of hand, question is asked and answered : adding a app via proxy which may interop-unlock other WP is not possible. Locking thread now.
PS : yay, ten posts.
When developing an application for desktop windows, there's always a way to access functionality - sometimes through back doors like the registry, etc... I'm developing an application for Windows Phone 8.1, but there are certain pieces of functionality that aren't exposed in the PRT APIset that is available to me. For example, we want to ensure that the user has password protection on the lock screen when using the application. There doesn't seem to be any associated APIs to readily use. So my question is, are there back door ways to do such things? How? Is there a way to access ALL system settings - like a registry or something of the like?
proch said:
When developing an application for desktop windows, there's always a way to access functionality - sometimes through back doors like the registry, etc... I'm developing an application for Windows Phone 8.1, but there are certain pieces of functionality that aren't exposed in the PRT APIset that is available to me. For example, we want to ensure that the user has password protection on the lock screen when using the application. There doesn't seem to be any associated APIs to readily use. So my question is, are there back door ways to do such things? How? Is there a way to access ALL system settings - like a registry or something of the like?
Click to expand...
Click to collapse
Another question would be - if something like intune can enforce lock screen password policies, shouldn't I be able to do it the same way that intune does it? If so, how? If not - why not?
It's not possible to check if user enabled lock screen password or not as far as I know
but if you want to made your app secure (because it may include important data)
you can create a password for your own application !
I did it in a little notepad app my password page allow user to set a password with all English and Persian Characters , numbers and special Chars like [email protected]#$ and etc.
Sent from my RM-994_eu_poland_1183 using Tapatalk
It's pretty easy to check, using the registry, but at least in 8.0 that's not allowed at all for store apps (your app would get rejected). I don't know if the rules changed for 8.1. There are ways to sneak past the store checks, but they could pull your app from the store if they ever found out. I know of at least three ways to access the registry APIs (4 in WP8.1) and two of them are pretty hard to detect unless somebody checks for them specifically... but they're the kind of technique that malware uses, so such checks may be in place.
I don't know what InTune is doing, specifically - I'd need to pull the app apart to see - but there are special application capabilities (not normally available to third-party developers) that can query and even set policies. Apps without those capabilities will get Access Denied if they try to use the same methods though, and normally you can't add those capabilities to your app.
GoodDayToDie said:
It's pretty easy to check, using the registry, but at least in 8.0 that's not allowed at all for store apps (your app would get rejected). I don't know if the rules changed for 8.1. There are ways to sneak past the store checks, but they could pull your app from the store if they ever found out. I know of at least three ways to access the registry APIs (4 in WP8.1) and two of them are pretty hard to detect unless somebody checks for them specifically... but they're the kind of technique that malware uses, so such checks may be in place.
I don't know what InTune is doing, specifically - I'd need to pull the app apart to see - but there are special application capabilities (not normally available to third-party developers) that can query and even set policies. Apps without those capabilities will get Access Denied if they try to use the same methods though, and normally you can't add those capabilities to your app.
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Thanks for this great and detailed information. See, that's exactly what I'd do if I were developing a desktop app - since i know that intune does it, I'd figure out how intune does it and voila. I'm finally getting over the idea that the same methodologies apply to windows phone development.
For my own educational purposes (since I want to understand this platform better), I would really like to know specifically how you go about accessing the registry APIs (for example). If there's any way for you to describe any number of these methods, I'd greatly appreciate it. Thanks again!
My NativeAccess libraries (check my signature, or search on the forum or on Codeplex) contain an example of one way to access the registry. The code is open-source; you may use the libraries as-is (don't expect to get them into the store, though I won't stop you from trying), use the source code as a reference, or modify/build them yourself; the license is very liberal (MS Permissive). The functions I use are generally documented on MSDN, in the desktop APIs section; the phone has the same functions, although the DLL names are changed and the header files hide them.
Hello - I am doing a pen test for a customer. They are not giving me the xap files like they did last time. Is there a way to pull the xap file off the phone and on to your PC? I have a dev unlocked phone which I can sideload apps using power tools. I have done some research and it doesn't sound like this option is available, but I wanted to ask.
Thanks in advance.
First of all, the phone doesn't store the XAP files (PLEASE search before posting! This question gets asked a lot). I assume all you really care about is the app binaries and manifest file, though. (You can rebuild an installable XAP from these if needed.)
There's a complicated series of hacks for doing it on 8.1 via the ability to install apps to the SD card. If you don't have 8.1, don't have an SD card, can't install the relevant versions of specific apps, or if the app is marked to not allow installation to SD, then that method won't work for you.
The other approach, which in my experience is standard in the pentesting world (which is my field as well), is to use a hacked/jailbroken/unlocked phone. Samsung (unless it has the very newest firmware versions) and Huawei phones can be unlocked by flashing modified ROMs. The unlock lets you sideload apps with vastly more privileges, such as the ability to read and write the install directory of any app. Using that, it's pretty easy to get the files you want. Such unlocks are also possible with some Nokia phones via JTAG, and possibly some other models too, but the Samsung unlock (which I and -W_O_L_F- found) and the ability to flash customized ROMs for Huawei are the easiest approaches.
On the offhand chance you're part of NCC group, PM me and I'll send you my work email address. If you're with one of our competitors... well, I actually don't mind helping a competitor that much either; some Deja Vu folks gave me a good tip lately though, and I've got friends at SI as well.
GoodDayToDie said:
First of all, the phone doesn't store the XAP files (PLEASE search before posting! This question gets asked a lot). I assume all you really care about is the app binaries and manifest file, though. (You can rebuild an installable XAP from these if needed.)
There's a complicated series of hacks for doing it on 8.1 via the ability to install apps to the SD card. If you don't have 8.1, don't have an SD card, can't install the relevant versions of specific apps, or if the app is marked to not allow installation to SD, then that method won't work for you.
The other approach, which in my experience is standard in the pentesting world (which is my field as well), is to use a hacked/jailbroken/unlocked phone. Samsung (unless it has the very newest firmware versions) and Huawei phones can be unlocked by flashing modified ROMs. The unlock lets you sideload apps with vastly more privileges, such as the ability to read and write the install directory of any app. Using that, it's pretty easy to get the files you want. Such unlocks are also possible with some Nokia phones via JTAG, and possibly some other models too, but the Samsung unlock (which I and -W_O_L_F- found) and the ability to flash customized ROMs for Huawei are the easiest approaches.
On the offhand chance you're part of NCC group, PM me and I'll send you my work email address. If you're with one of our competitors... well, I actually don't mind helping a competitor that much either; some Deja Vu folks gave me a good tip lately though, and I've got friends at SI as well.
Click to expand...
Click to collapse
Thanks again for all your help. So my situation is this: I am doing pen testing for a client (and I'm sure we are competitors some what). The have provided me a Nokia Lumia phone running 8.0 and another Lumia running 8.1. The app is installed by their dev team (app is not avail from the store). They are reluctant to provide my the XAP file as they consider it proprietary info. I have done a dev unlock on the phone, but my primary goal is to view the isolated storage/dlls for the app to make sure they are not storing sensitive data. I am using the standard tools for viewing the isolated storage, but for these to work (best of my knowledge) they require you to sideload the application which I cannot due (not XAP file). I am proxying the traffic, but without looking at the file system there is not much I can do. As an aside, they are using MDM with jailbreak detection.
Whoa, somebody actually got around to writing jailbreak detection for WP8? Crazy. I wish I could see that; I'm sure it's trivial to bypass (at least for interop-unlock, the difference between locked and unlocked is changing a registry value and it would be easily possible to re-lock it, launch the app while keeping the editor app open in the background, switch back to the editor, and unlock/jailbreak again) but I'm amused that anybody even bothered trying. Also, the APIs you would need to do the detection aren't even available on 8.0, officially; you're in violation of the store rules if you use them. Then again, maybe this is an internal, "Enterprise" app; those have permissions to do stuff that typical third-party apps do not. Are you sure they don't just mean they have jailbreak detection for iOS? I see something about Office365 MDM offering JB detection, but while I suppose they could have written something for WP8.x as well I feel like I probably would have heard of it?
If the app was sideloaded by the dev team, then you can see its isostore using the official tools or using Windows Phone Power Tools. If it's an enterprise app and the app was installed that way, then things get more difficult (especially if the phone they gave you doesn't have an SD slot). Not giving a pentester access to the binary they're testing is silly on a number of levels; if you succeed in breaking in then you'll get it anyhow, and an attacker will have a lot more than a week or two to poke at it so they're wasting your presumably-paid-by-the-hour time if they want you to see how good their security is without actually examining the app. I bet they used obfuscation, too... Some people just don't get it. "Security" by obscurity... isn't. Sorry, end of mini-rant. Anyhow, there's a guy on the forum who claims to have a non-JTAG unlock for Lumias, but no idea when or if it'll see the light of day.