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Greetings,
This is my first post here, so forgive me for posting in the general forum and not in the dev forums (I have to accumulate 10 posts to use the dev forums). I have a very important and worthwhile project that I'm hoping will interest a few devs here.
I am attempting to build a proof-of-concept for a very large educational institution that is considering implementation of ebook readers. Obviously, stock ebook readers are not up to what we need, and more robust tablets like the Galaxy Tab are cost prohibitive given the goal of distribution of these devices to tens of thousands of K-12 students. I don't want to be stuck with a single book distribution method, so I am looking for some standard Android flavor rather than a Nook-like interface.
So, here's my challenge to you. I would like to use the Nook Color (the $250 price point is perfect) to build a proof-of-concept low-end, semi-restricted Android tablet. I am looking for:
- Android 2.2
- Flash Support
- Ability to run:
- Dolphin Browser
- Regular Nook Android App
- Kindle App
- Google Book Reader App
- Adobe Reader App
- Some (undefined) Calculator App
- Stock Android Calendar App
- Stock Android Mail App
- Google Maps App
- Google Earth App
- Stock Android Gallery App or Equivalent
- Some (undefined) File Manager App
- Some (undefined) Note Taking App
I would also like the ability to load APK files (that we write) without the use of the Android Market. And . . . I need the final installation to *NOT* have root capability.
Anyone have a ROM to start this?
Also, while I'm somewhat familiar with rooting other Android devices, I'm not a developer and not a linux expert. I employ developers that have written a few Android apps, so they can handle the installation if necessary.
Any takers?
You can contact me off-list if you like at Dwayne at leeschools.net.
Thanks,
Dwayne
Wouldn't a $200 netbook be a far more usable tool to a student?
good thing you didn't post this in development.
once nook is updated to 2.2 this will basically all be possible with just root.
supposed to be released soon....
if you want a custom rom those will be around soon as well.
--edit--
i see you want this all without root. i don't believe that is possible. good luck though
There are specific reasons we are not considering netbooks for this project, beyond the scope of this discussion. For the purpose of this POC, we are only looking at touch-based slates.
I can't think of a way to fully disable root without someone being able to add it back. With that said would you be able to just delete the marketplace to make it "locked down" after installing everything? Possible disable super-level access as well?
I've not seen any confirmation that they are going to update to 2.2. I've only seen rumors to that effect. Do you have evidence to the contrary, because that would be great.
Additionally, the reason I'd like to involve the devs is because it is highly unlikely that B&N will release it with anything close to a stock 2.2 install. It will likely still require quite a bit of work to function normally. Hopefully I'm wrong on that account, but based on B&N's business model, I anticipate that they will do their best to prevent it from being used as a full tablet. They want to sell books. I don't think they want to sell devices without books. Not enough margin in the devices.
Perhaps I'm wrong related to their business model. I have approached B&N and requested an NDA to work with the Nook product team to see if they are interested in working together with us on a customized version. My feeling is that if they make very little on the device (with the goal of making the majority of their profit from content), they'll decline this offer.
MattJ951 said:
I can't think of a way to fully disable root without someone being able to add it back. With that said would you be able to just delete the marketplace to make it "locked down" after installing everything? Possible disable super-level access as well?
Click to expand...
Click to collapse
We could remove super user, but I'd also like to prevent users from killing services. I anticipate that we'll need some additional security apps that need to run full-time. One of our big challenges is that, by law, whenever we provide an Internet-capable device for students to take home, we are required to filter Internet. That's a huge task. On a PC, we an lock it down and force traffic through our filters from outside. From an Android device, we don't know how to handle that yet. We have a few approaches. I'm in discussion with M86 regarding an Android equivalent to their mobile client.
But . . . we have a lot more experience locking down a Windows or Mac PC than a phone OS. Most phone OSes are built from the perspective of a consumer, where the user is free to add/remove apps. We need a way to deal with that. Haven't gotten that far yet. The first order of business was to see if we can build our base functionality in a $250 device.
DwayneA said:
I've not seen any confirmation that they are going to update to 2.2. I've only seen rumors to that effect. Do you have evidence to the contrary, because that would be great.
Additionally, the reason I'd like to involve the devs is because it is highly unlikely that B&N will release it with anything close to a stock 2.2 install. It will likely still require quite a bit of work to function normally. Hopefully I'm wrong on that account, but based on B&N's business model, I anticipate that they will do their best to prevent it from being used as a full tablet. They want to sell books. I don't think they want to sell devices without books. Not enough margin in the devices.
Perhaps I'm wrong related to their business model. I have approached B&N and requested an NDA to work with the Nook product team to see if they are interested in working together with us on a customized version. My feeling is that if they make very little on the device (with the goal of making the majority of their profit from content), they'll decline this offer.
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Click to collapse
Dude, all of those hings are capable. Have you done any reading in this forum. Just get a nookie froyo 2.2 card set one up the way you want. uninstall super user and market. make lotsa copies of card and stick it in nook. If you really want you can also trash the firmware on the internal memory so it will not even book the stock nook firmware.
enjoy!
Consideration should be taken that rooting technically voids the manufacturer's warranty. Other than that, using the NookColor as a tablet is still a gamble in terms of getting a rock-solid and reliable device. Supporting the devices may be problematic.
Fortunately, the devs here are doing great work and I fully expect (hope) that it will be a rock-solid reliable device very soon.
You will probably also want to avoid booting from the microsd because they are easy to remove.
Filtering could be done with a VPN.
to avoid removal of micro sd, just put a little sugra on the break where the nook opens for the micro sd, sort of lieka warrenty sticker
If you need help. Let me know.
The Nook Color already has a Froyo image that can be installed. DSP currently doesn't work. That is responsible for video decoding not only for local files, but for Flash video as well.
Other than that, Flash will still run, but not on all occasions, and the rest of your requirements have already been accomplished (ie. apks can be installed and already exist on the Market or from the Internet).
You can install the Froyo image (it consists of a boot image and a system image) to your Nook easily, and afterward install all of the "G" apps with a quick copying of a folder.
Check here: http://forum.xda-developers.com/forumdisplay.php?f=864
- Do a little reading
- Possibly try installing Froyo on your memory card first.
- PM me if you need any guidance. I'm feeling pretty PRO at this after using adb all weekend to work with my Nook.
FYI: You can completely hose your internal installation and still be good (As long as you don't actually corrupt your memory physically). The Nook can always be booted off of a microSD card and restored to a fresh installation.
Edit: I just read some of your other posts. Just a thought: You could uninstall or disable the browser by default, thus not having to worry about Internet filtering. Later, users could still install apks from the sdcard (All that you have to do is tick a box in "Settings"). You can also do all of this without touching the stock rom. Of course you'd want to disable that from booting ever, so... after you were booted into your microSD card OS you could use adb to delete the content of the mmcblk0p1 (boot) partition. But I think that still might go against BN's warranty rules.
I understand the reasoning of wanting to lock it back down but if your students are capable of finding XDA (I'd imagine 1 or 2 of them is, at least) then that person would probably root the systems for anyone who was so inclined. I mean, B&N wasn't able to stop it, it's not likely that you would (without some sort of remote supervision app that could monitor and detect rooting).
gallahad2000 said:
I understand the reasoning of wanting to lock it back down but if your students are capable of finding XDA (I'd imagine 1 or 2 of them is, at least) then that person would probably root the systems for anyone who was so inclined. I mean, B&N wasn't able to stop it, it's not likely that you would (without some sort of remote supervision app that could monitor and detect rooting).
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Click to collapse
that was going to be my 2cts. A student would just have to pop in an sd card. And it would be a little unfair not giving student that right? And even then, they could always push something over via adb.
Have you looked at other options like the Archos line of Android tablets?
Otherwise, the SD Card install of Froyo works well - just superglue the opening
Why would any school district buy tablets with no warranty? Doesn't seem that feasible to me.
blackderbyhat said:
Why would any school district buy tablets with no warranty? Doesn't seem that feasible to me.
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Click to collapse
He's only looking for a proof of concept right now, and is trying to work with Barnes and Noble directly.
I forsee many broken nooks in our future.
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...
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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.
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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.
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.
Hello,
I'm just starting my dev journey with WP8 with my new T-Mobile Lumia 520.
First what I need to do is to debrand my lumia - for faster updates. T-Mobile is not offering yet the next release of fw which allows to disable images in IE, and as dev I need to be up-to-date as fast as possible. I need to download the FW, but I don't know which one - localized for sure, but what GDR is? What Amber means? I can't decide which one do I need to download and flash. (http://forum.xda-developers.com/showthread.php?t=2515453 This instruction doesn't show the moment of decision).
Next question is about unlocking. I'm downloading music from Soundcloud via Cloudoh and I want to access them from my PC, same as files located inside of other apps - do I need to unlock the device to do that? For example - how to upload a pdf from PC to winpho pdf reader?
Windows Store allows me to download installable files at PC and install them via SD Card. Some apps aren't supposed to work with my device. Is there any solution how to install them at my risk?
And the last question, but not least - I have my dev account but its time limited and app-count-limited. Is there any way how to check if my Lumia is dev-unlocked, how long this unlock lasts and what is my current app-limit? Just for my information - I like to have the ways to check everything.
Please, help me
GDR = General Distribution Release (a brief web search would have told you this). Microsoft-ese for a post-initial-release update (think of service packs for other MS software). The current version is GDR3, also called Update 3. "Amber" is Nokia's codename for the firmware version that they ship along with GDR2. "Black" is Nokia's firmware name for GDR3. Note that OEM firmware (such as Amber or Black) are different from Microsoft OS updates (such as GDR2 or Update 3), although they are typically delivered together. If you're already on at least GDR2, you can get Update 3 directly from Microsoft without waiting for T-Mobile or Nokia; search the Store for "Preview for Developers".
You cannot access files stored inside an app from anywhere else, either a PC or another app, unless the app explicitly makes them available by including a method to export them. Most apps don't implement this. The only exceptions to this rule are for images (which can be stored in the Pictures Library of the phone, much like the built-in camera app or screenshot functions) and OEM apps, which can have extra permissions (Capabilities, such as ID_CAP_PUBLIC_FOLDER_FULL) that aren't allowed for third-party developers. However, for development apps (that is, ones which were sideloaded to your phone from an unsigned XAP file), you can access their Isolated Storage from your PC using the aptly-named Isolated Storage Explorer Tool (or any other program that implements the required APIs, such as Windows Phone Power Tools).
To upload a PDF to the phone, you can do any number of things. Over USB, copy it to the Documents folder on the phone using any MTP software (Windows Explorer works). Over Bluetooth, just send the file directly. Over email, just attach the PDF. Over the Internet, you can use SkyDrive, or any other "cloud" app, or if it's on a web server you can get it from the phone's browser...
I'm not aware of any work-around for the minimum-memory restriction on some apps. I believe it mostly only applies to large games? In any case, you have one of the lowest-end WP8 devices on the market; there are limits which come with that.
The official way to tell if your phone is dev-unlocked is to use the Windows Phone Developer Registration tool, the same one you use to do the dev-unlock in the first place. A paid developer account always gives a limit of 10 apps (the free one is 2 apps). There's no official way to tell how many apps you have remaining, but it's simple enough to tell if you have any space left; just try sideloading any app that isn't already installed!
GoodDayToDie said:
GDR = General Distribution Release (a brief web search would have told you this).
Click to expand...
Click to collapse
Yeah, I did some sort of search on forums and Google and I haven't found anything.
GoodDayToDie said:
You cannot access files stored inside an app from anywhere else, either a PC or another app
Click to expand...
Click to collapse
After unlock it is still unaccessible? I had to jailbreak my iPad because without jb it is not easy to operate. I thought about something like this for Lumia. I think it is only the need of time for others to omit this problem
Disney offered lastly a promotion for its games. I was interested with some of them, but only one was accessible for my device. xap file needed only 70 mb of space. I think there was a problem with performance, but if I want see a laggy game I should have the ability to install it despite everything.
There's no jailbreak available for Lumia phones yet. Something like that should, indeed, allow accessing the storage of the apps (and everything else) but we don't have one...
The size of the XAP has very little to do with the runtime requirements of the app (RAM and CPU). I have written apps of only a few kilobytes that required over 10 gigs of RAM to run (not a phone app, obviously). To avoid people with low-end phones getting annoying with the platform and thinking it's the fault of either Microsoft or the app developer when an app crashes from running out of RAM, they've prohibited installing high-RAM apps on low-RAM devices.
You mean T-Mobile's Lumia 521 right? There's no other ROM you can flash to it that might have the update.
Hi,
So, Android has a permission system which albeit somewhat flawed (malware can gain permissions not intended for it) and not very suitable for laymen (non rooted phones have to either accept all permissions or be denied from the app. In many programs people don't have the luxury of not using them) theoretically has merit. IOS has...well actually I'm not sure how it works security wise but I pressume it creates sandboxes for each app, layman wise it is reasonable since you (theoretically) can deny access for all programs to certain components (no need to jailbreak).
How does WP works?
Thank you.
Security is different, apps can't do as much as on android. But iOS is better in this, because capabilities are like in Android: you can see what the apps want prior to installing them, but blocking some of them isn't possible.
I am very saddened to hear this.
Is there an ability in place similar to Androids rooting?
Also, what do you mean by "apps can't do as much as on android"?
Thank you!
@th0mas96's post is technically *mostly* accurate but very confusing and doesn't actually answer your question at all.
The short version is that WP apps use a capability-and-sandbox system much like iOS and Android, with each app getting a sandbox that gives it read-only access to the app-specific install directory and the global system directory, read/write access to the app-specific data directory, and access to whatever other stuff is specified in the capabilities. Capabilities are currently all-or-nothing; you can't reject or disable any capability except by just not installing the app.
I could go into the technical implementation of the system a bit, but the short version is that WP8 apps use fairly standard NT (as in the NT kernel that is at the core of PC Windows versions) security features: each app has a unique token (rather than inheriting the token of the process that crated it, the way it normally works on PC but very much like how Windows Store apps work on Win8) which contains the app-specific Security IDentifier (SID) that gives access to the app directories, plus the SIDs of the various capabilities that the app has.
What @th0mas96 was talking about is that WP capabilities usable by third-party developers are much more restrictive than they are on Android. For example, Android allows an app have full read-write access to your contacts or to send SMS directly. WP8 doesn't allow that unless you use capabilities that are normally neither allowed on the store nor allowed in sideloaded apps (Microsoft's code can have them, of course - that's how the built-in SMS app works - but not Joe Random Dev). The downside of this is obvious; some app behaviors (like a full replacement for the SMS app or phone dialer) are not possible. The upside is that apps are *way* more limited in how malicious they can be; the most common way that Android malware makes money (remember, the vast majority of malware is for profit) is by sending SMS to "premium" numbers. On WP8, an app could *compose* such a message, but it couldn't *send* it for you (unless it had a capability that third-party apps normally can't have) so you'd have a chance to see what the app was doing and decide not to send that message after all.
This means that the ability to disable capabilities is much less important on WP8 than on Android.
Oh, then those restrictions are actually good news.
Aside from from your typical run-of-the-mill malware my main concern was actually privacy. I have a huge displeasure from apps like Whatsapp which on android takes a whole plethora of liberties and was hoping that perhaps some other system may contain their user data voracity and their ability to control the divice their on.
Is there any link in which I could see the full list of those restrictions?
I'm still downhearted from not having a more fine grained control of the system but maybe it still has it uses in some scenarios...
Also, thank you very much for your comprehensive explanation!
i found a tiny file stored inside some of the unbranded htc accord RUUs. its call disablewriteprotect.test. the only thing the file contains is a sentence stating write protection will be disabled until this file is removed. followed by a music note and some other symbol. so there you go thats how you make your entire htc 8x read and write. one file less than 1kb in size. ROOT!
but how can we flash this file. im still working on it. this file is located within the efi partition which also houses the ffuloader.efi, and severl other efi executables. check this post http://forum.xda-developers.com/showthread.php?p=53687985#post53687985
you wont find that on google search.
Sent from my Galaxy Nexus using XDA Free mobile app
Window phone Security Issues
Your Windows Phone is secure by design. Many security features are turned on by default. For example, apps you download from the Windows Phone Store are tested by Microsoft and encrypted to make sure you don't accidentally install malicious software on your Windows phone.
Set a password
Setting up Kid's Corner
If you've ever handed your smartphone to a child, you know that they can quickly get into all sorts of apps and settings they shouldn't. No such worries with Kid's Corner, a place on your phone where your child can play with the games, apps, music and videos
Use the free Find My Phone service
Say yes to updates . check out more at Master Software Solutions - Windows Phone Update
grilledcheesesandwich said:
i found a tiny file stored inside some of the unbranded htc accord RUUs. its call disablewriteprotect.test. the only thing the file contains is a sentence stating write protection will be disabled until this file is removed. followed by a music note and some other symbol. so there you go thats how you make your entire htc 8x read and write. one file less than 1kb in size. ROOT!
but how can we flash this file. im still working on it. this file is located within the efi partition which also houses the ffuloader.efi, and severl other efi executables. check this post http://forum.xda-developers.com/showthread.php?p=53687985#post53687985
you wont find that on google search.
Sent from my Galaxy Nexus using XDA Free mobile app
Click to expand...
Click to collapse
Sounds interesting.
Not something I'd try )) but interesting.
Aman Raien said:
Your Windows Phone is secure by design. Many security features are turned on by default. For example, apps you download from the Windows Phone Store are tested by Microsoft and encrypted to make sure you don't accidentally install malicious software on your Windows phone.
Set a password
Setting up Kid's Corner
If you've ever handed your smartphone to a child, you know that they can quickly get into all sorts of apps and settings they shouldn't. No such worries with Kid's Corner, a place on your phone where your child can play with the games, apps, music and videos
Use the free Find My Phone service
Say yes to updates . check out more at Master Software Solutions - Windows Phone Update
Click to expand...
Click to collapse
I pressume this is an advert for Master Software Solutions, but nevertheless I did google the term you suggested and got nil results. I also browsed the main site of the company itself but haven't found anything related, nor did I find anything on their facebook page.
Regardless, I checked out this Kids corner thing, it's cute but not really security related...
Thx anyway.