[Q] Decompile XAP file from the MarketPlace - Windows Phone 8 Q&A, Help & Troubleshooting

Hi,
I downloed XAP file from the market place (There is an option called "Download & Install Manually" in the app page in the store).
I want to open XAP file and see the source code (with Reflector, JustDecompile or somthing), but I can't because XAP files from the market are DRM signed I guess.
Do you know any way to accomplish that?
I have Lumia 920 developer's unlock, and also the Visual Studio 2013 emulators.
Thanks.

sholomiel22 said:
Hi,
I downloed XAP file from the market place (There is an option called "Download & Install Manually" in the app page in the store).
I want to open XAP file and see the source code (with Reflector, JustDecompile or somthing), but I can't because XAP files from the market are DRM signed I guess.
Do you know any way to accomplish that?
I have Lumia 920 developer's unlock, and also the Visual Studio 2013 emulators.
Thanks.
Click to expand...
Click to collapse
A workaround of DRM protection was put online here there is very little time.
But the topic has been deleted. So, not any means currently.

anaheiim said:
A workaround of DRM protection was put online here there is very little time.
But the topic has been deleted. So, not any means currently.
Click to expand...
Click to collapse
It were nothing about decrypting DRM-protected XAPs from marketplace, just a way to make non-encrypted XAP from the already installed app. Also the app you`re making xap from must user CAPs not higher that regular 3rd party developers can use, instead you can not install an app again because no free/software interop or better unlock is achived for Nokia phones.
AFAIK even unlocked with all known ways Samsung Ativ S can`t decrypt those marketplace XAP's, so the answer is no, it`s not yet possible.

It is possible, after a fashion, but not directly. This whole topic is sketchy as heck. If you tell me why you want to do this, I may help you - I've decompiled apps before; we'd never have gotten interop-unlock on ATIV phones without it - but I'm not just going to post the method on a thread like this one.

GoodDayToDie said:
It is possible, after a fashion, but not directly. This whole topic is sketchy as heck. If you tell me why you want to do this, I may help you - I've decompiled apps before; we'd never have gotten interop-unlock on ATIV phones without it - but I'm not just going to post the method on a thread like this one.
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Click to collapse
Hi, first of all, thanks all for the answers.
The reason that I need to decompile an app from the store is because it's my app that I'm trying to decrypt.
I lost the source code of my app that is already in the store, and I'm looking for a way for restoring it.
If you can help me, it will be great !
it also very intersting me as a developer the way to accomplish that, I had tried all my best...
Thanks.

The name of this application?

titi66200 said:
The name of this application?
Click to expand...
Click to collapse
Surely OP will deliver.

GoodDayToDie said:
It is possible, after a fashion, but not directly. This whole topic is sketchy as heck. If you tell me why you want to do this, I may help you - I've decompiled apps before; we'd never have gotten interop-unlock on ATIV phones without it - but I'm not just going to post the method on a thread like this one.
Click to expand...
Click to collapse
I need to decompile some apps since they are legacy xap which Ms cancelled after Nokia acquisition.
These would not install on win 10 mobile since it can't install xap and we can't deploy store xap.

GoodDayToDie said:
It is possible, after a fashion, but not directly. This whole topic is sketchy as heck. If you tell me why you want to do this, I may help you - I've decompiled apps before; we'd never have gotten interop-unlock on ATIV phones without it - but I'm not just going to post the method on a thread like this one.
Click to expand...
Click to collapse
i also want to decompile some apps like(tapatalk , nokia refocus and lots of other nokia apps)
can you help me

Related

developer unlock wp8?

Hi
I am thinking about paying the 99$ fee and was wondering if I can developer unlock my Samsung ativ s or a lumia 928?
and if I do can I sideload the recently pulled youtube xap onto my phone and for that matter maybe 7.x homebrew apps onto wp8?
noelito said:
Hi
I am thinking about paying the 99$ fee and was wondering if I can developer unlock my Samsung ativ s or a lumia 928?
and if I do can I sideload the recently pulled youtube xap onto my phone and for that matter maybe 7.x homebrew apps onto wp8?
Click to expand...
Click to collapse
I haven't looked into it much, but I believe that you can only sideload 3 individual applications onto it. All modern Xaps are encrypted, too, and we don't have any way to decrypt them, so even if you could get it you likely couldn't sideload it.
i see
netham45 said:
I haven't looked into it much, but I believe that you can only sideload 3 individual applications onto it. All modern Xaps are encrypted, too, and we don't have any way to decrypt them, so even if you could get it you likely couldn't sideload it.
Click to expand...
Click to collapse
well i was wanting to factory reset my ativ and unlock it and sideload the youtube xap because i inadvertently put too any apn apps on my ativ s to try and get internet sharing to work.
because of this every time i soft reset the phone it takes a solid 5 minutes or more to get the internet connection back cause off all the apns floating around in settings that i can't uninstall
i love version 1 of the Microsoft youtube app overhaul and don't want to give it up with a factory reset, i am also thinking about selling my ativ for the lack fo decent oem camera software and go with the lumia 928 but once again i want to get that youtube app back onto whatever phone im using
but like you said they are encrypted anyway which is bad to hear, sigh are they ever going to jail break wp8, i am languishing here without a custom rom, if they could somehow crack wp8 and my ativ s , then my ativ s could be a super phone with all of nokia and htc software installed too
sigh!
You could simply use another YouTube App like MetroTube. I still prefer it over Microsoft's now pulled App and you don't have to play around with Unlocks and what not...
I developer unlocked my HTC 8x a while ago, and I can tell you the following:
1. If you developer unlock you device for $99/yr, you can sideload as many apps as you want. The limitation of 3 only applies to student accounts.
2. Any xap from the Windows Phone store can be sideloaded, as long as it doesn't require Interop Unlock.
3. The Xap files are just specially packaged zip files, so you can edit them with a tool such as 7zip.
4. If you downloaded an xap from the Microsoft store, and then try to sideload it, it will fail, until you delete "WMAppPRHeader.xml" from the xap. This also will "break"
updates for the app as new ones come out in the store.
Hope that helps!
Can I:
1. Sideload 7.x homebrew caps?
2. Sideload the Microsoft YouTube app that was pulled? I have the xap, so I should delete that file you mentioned?
3. Do I use the side load program that you use on your desk top (I forgot the name) in the chevron wp7 days
Someone had told me offhand regarding the YouTube xap that it is encrypted and useless to try and side load anyway, is this true?
Thank you very much for your help!
Sent from my SGH-T899M using XDA Windows Phone 7 App
Sideloading WP7 apps will "work" except that most WP7 homebrew either requires Interop Unlock (which we don't have yet) or requires "root" privileges (which we don't have yet). So... not a lot of use.
GoodDayToDie said:
Sideloading WP7 apps will "work" except that most WP7 homebrew either requires Interop Unlock (which we don't have yet) or requires "root" privileges (which we don't have yet). So... not a lot of use.
Click to expand...
Click to collapse
Do you think it will be easier to gain interop-unlock if the phone would already be dev-unlocked?
If this would be, i guess i would pay the 99$ to dev-unlock my Lumia 920, if it helps the community
I can't open Xap to remove "WMAppPRHeader.xml" (DRM protect)?
You have to change the xap with 7zip and it will turn into a zip file with additional files inside, I would like to know if I deleted "wmappprheaderxml" in Microsoft's ill fated YouTube app could I then sideload it?
Sent from my SGH-T899M using XDA Windows Phone 7 App

[Q] Password protect certain applications?

Is there an application that can password protect certain apps that I choose?
And please do not say Kids Corner as it does not do what I am asking.
It's probably possible (though far from easy), but I'd actually be more inclined to help if you hadn't opened a duplicate thread about this.
Only made second thread about this to attract some attention, 7 months passed since that guy opened his thread and nobody could give a good answer.
To me it's weird that nobody tried to make an app like this still, it would be very popular and help users very much.
Anyways, thank you for replying.
Really, just bumping the other thread was enough, but since we're here anyhow... my idea for how to approach it (and this would take a *lot* of hacking) goes something like this:
1. Create an app (call it X) that has the capability to launch other apps, and filesystem write access.
2. Have X take another app (call it Y) and encrypt its binaries. This prevents anybody from launching it by any means.
3. Tweak the app database to make it so that when you try to launch Y, it instead launches X and passes the id of Y as a parameter to the launcher.
4. X prompts the user for a password to Y. On getting the right one, it decrypts Y's binaries and writes them back to the correct location, then launches Y.
5. When the user (or OS) closes Y, a background process of X notes that Y is closed and re-encrypts it.
Currently we know how to do... well, some of #1, and we think the rest is possible. Given that, #2 isn't too hard. #3 is something I don't have the least notion how to do *right now* but I'm sure it's possible. #4 shouldn't be too hard given #1 and #2. #5 will be a trick - currently, apps have no way to know what other apps are running - but I'm sure it can be done.
It's a large engineering problem blocked by an even bigger research and hacking problem, though. Nothing we'll have soon. You'd never be able to publish it in the store, either, and it would only work for people with hacked phones. It's exactly the kind of *useful* thing that would be possible if Microsoft were willing to let up the restrictions on third-party developers a bit, of course, But for the time being, there are *reasons* nobody has done it yet.
Well the word that I actually was thinking after reading your post was "crap".
It seems only with time (and a whole [email protected]#$ing lot of it) will wp become a true competitor to android, but to be honest I don't think it will come to that.
Thanks for replying GoodDayToDie, I'm freakin' sad that there is no app that can suit my needs, I even tried with kids corner but the screen still needs the password entered like the normal one. Nothing really can make up for what I have in mind.
Cheers mate.
as soon as we can interop unlock all WP devices, it will be pretty easy... if you're able to provide the XAP (uncrypted of course )
i'll be able to "mod" this in for you... which app are we talking about?
@GoodDayToDie: i do'nt think he is looking for real data security here, so encrypting the whole thing shouldnt be required... i think it's more about preventing his gf to read his private messages or something like that
oh btw.: you would need a dev-unlock to deploy the modified XAP then...
tfBullet said:
as soon as we can interop unlock all WP devices, it will be pretty easy... if you're able to provide the XAP (uncrypted of course )
i'll be able to "mod" this in for you... which app are we talking about?
@GoodDayToDie: i do'nt think he is looking for real data security here, so encrypting the whole thing shouldnt be required... i think it's more about preventing his gf to read his private messages or something like that
oh btw.: you would need a dev-unlock to deploy the modified XAP then...
Click to expand...
Click to collapse
You're right tfBullet! I need it for whatsapp, photos, message and games app, mostly to prevent from friends but gf too.
I was thinking it might be possible to mod an app and add password before it can be accessed, although I have no experience in this domain. Many apps in store have this function, like wallet or prive photo apps.
My phone is dev-unlocked as I started a few days ago to study and try to create a simple app for me and my friends.
Modding an app like that would actually be quite hard, because it would break the signature and prevent the app from running. The encryption thing really isn't too hard, although you could skip it anyhow too.
If there was a way to run a program in the background that monitors when certain apps are selected and then prompts when its activated would work, but it would need an unlocked phone. And even under home brew I don't know if its possible to run apps in the background. Yet.
Sent from my Nokia 521 using XDA Windows Phone 8 App
The encryption thing really isn't too hard
Yea, but that's a little extreme. If you can create that password program that runs in the background you could probably have it watch files, apps or pretty much anything. You'd have to password protect the cofig file. And maybe if you can't remember the password after so many attempts you can have the program email the passwords to your email. Just some ideas.
Sent from my Nokia 521 using XDA Windows Phone 8 App
Running software in the background is actually shockingly easy. The trick is getting it to run with better-than-app-sandbox privileges. We're still working on that one. In the meantime, apps can't even read, much less write, to the install location of other apps.
GoodDayToDie said:
Modding an app like that would actually be quite hard, because it would break the signature and prevent the app from running.
Click to expand...
Click to collapse
@GoodDayToDie: actually these .NET apps are pretty easy to decompile, if you're willing to fix the bugs that the decompiler leaves you with...
so there is not really a need for a valid signature, if you're able to compile & sideload the app yourself
the only thing is: you need the decrypted XAP, as far as i know these get decrypted while installation and can be pulled from a interop unlocked device?!
It would be nice to get my fingers on some OEM (Nokia etc..) XAPs, to see if we can find any exploit in them
I know better than probably 95% of this forum what it takes to decompile managed code; I have reverse engineered huge numbers of apps. However, you are missing several important points.
1) Modifications like you suggest are very complicated to automate. It's certainly possible, but it's not simple.
2) Re-installing the app would be a pain. You would really want to do this as an in-place modification, and that means (for store apps) that it would still be signature-checked.
3) Not all apps are managed code; WP8 supports purely native code.
4) Even with managed code, obfuscation can make tinkering with the binary nigh-impossible.
It's just so incredibly stupid that WP is so limited. I know it's under Android big time, but I think even iOS more customizable, right?
Also, is there a message app in the store that has pass option? I searched but found nothing...
I don't believe iOS is any more customizable, no. It has some feature that WP lacks (it ought to; it's been out for years longer and Apple completely controls the hardware it runs on) but it's also missing some features that WP8 offers. In any case, this isn't the thread to have that discussion in.
GoodDayToDie said:
I don't believe iOS is any more customizable, no. It has some feature that WP lacks (it ought to; it's been out for years longer and Apple completely controls the hardware it runs on) but it's also missing some features that WP8 offers. In any case, this isn't the thread to have that discussion in.
Click to expand...
Click to collapse
But with the jailbreak and MobileSubstrate, iOS is extremely customizable, and there are tons of tweaks, that's where Apple gets its new features from
Back to topic, I think the OP would be happy with a solution that locks the "normal" user of his phone out of some apps, so it wouldn't be necessary to modify anything of it, just making the standard launcher (I don't know how it's called, but I mean when you launch the app via home screen or with a toast) ask for a password should be enough.

Idea for general (all phone brands) interop bypass (NOT UNLOCK) - but can it be done?

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.
Click to expand...
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.
Click to expand...
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.
Click to expand...
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.

[Q] Is there a way to pull a XAP file off WP8?

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.

Multiple Accounts on WP8.1?

Hello,
I'm new to WP8, and I did a search here but couldn't find anything...is there a way to switch Windows accounts on WP8.1 without doing a reset on the phone? Or a way to add more than one account? Any method would be great. Even in a browser. Need to give my apps some review boosts.
dkbovice said:
Hello,
I'm new to WP8, and I did a search here but couldn't find anything...is there a way to switch Windows accounts on WP8.1 without doing a reset on the phone? Or a way to add more than one account? Any method would be great. Even in a browser. Need to give my apps some review boosts.
Click to expand...
Click to collapse
no that isn't possible.
For the record, my disapproval of sockpuppetry in general and of using it to promote a product in particular means I'm not interested in helping you whether I know a way to do so or not. Have you considered attempting to promote your app through legitimate and ethical channels?
Closed thread. You SHOULD NOT be trying to game the system and boost your app through illegal means. Not cool dude

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