I'm making an app that read messages from Whatsapp, Viber, mails, etc. and groups it so you can read all that one person said to you in just one App.
To do this I'm trying to read the *.db files each App has on /data/data directory but have encountered two problems.
Since I'm new to programing for rooted phones I don't know how this works and have not found a good tutorial or any documentation. Do you have any that I could read to understand?
Once I know how to access /data/data with root, how can I read the *.db without making a copy. Many other topics say that I should copy the *.db file to a folder and read it there, but wouldn't it be a lot more simple to just read it from where it is?
Apps, regardless of whether the phone is rooted or not, can only ever read files that they themselves own, or that are public (e.g., on a SD card). This is because while the phone may be rooted, the apps themselves do not gain root access.
Instead, on your phone, you have an executable named su lets apps run root commands. However, by default, it refuses to let any app run any root commands. When you root your phone, you replace this executable by a new, modified version that lets approved apps run root commands. It is by using these root commands that you can gain indirect root access to the system.
Now, since you only have indirect root access for your app, you cannot just read any file from the file system. But if you run a root command to copy it to your own, private directory, where you do have permission to read it, your app can directly read it from there.
(Note: you can technically read files without copying them first, by using the su executable, but unless there's a real reason why you can't copy first, and you actually know what you're doing, you probably shouldn't even bother because it's rarely worth the trouble anyways, especially not for sqlite databases.)
For details about how to run root commands with su, see this link (which Gumbo posted in the comments above).
Related
I fully read the documentation of Cordova plugin filesystem. Furthermoe I've been googling without though conclusive explanations.
Particularly, how do the paths stored in the variables in cordova.file.* map the real folders in Android filesystem that you can see on any File Explorer? For example, I cannot save a file into the Downloads folder. I tried file:///android_asset/Download without success.
What exactly is the protocol file:/// and the path file:///android_asset/? What is the "application's sandbox"?
For example, I save a file into cordova.file.cacheDirectory because I need to deal with a temporary file, but I tried to find such file within a file explorer, and I can't find such file. Is it hidden somehow? I can't find it neither in /data/data/<app-id>/cache nor in "file:///data/user/0/com.form.parking.violation/cache/" (real value of that string).
I know, it's too many questions, but I will plan to make this a canonical question, since clear and pedagogical information is very scarce.
Using a 'File Manager' app on device won't give you access to items listed as 'Private' in the documentation you've listed. 'Private' means no other app should be able to see the contents which is sort-of described by "application sandbox". Normally a sandbox is for describing an environment which something can't get out of. If you aren't familiar with multi-user environments it can also mean that others without the right level of permission can't see in.
And unless the device you are testing on is rooted, you won't be able to see those 'private' files like the SQLite database and other files you are interested in unless you use adb from the Android SDK with the adb shell command run-as as described here:
Android ADB access to application databases without root
Note that to grab the files you need to have your Cordova app debuggable by Android Studio (debug mode).
For what is file:///android_asset/ I'll refer to this SO question:
What does file:///android_asset/www/index.html mean?
We all know that Android install apps in /data/app and app's data in /data/data.
I wonder if is possible to "ask" to the system to install the app in /sdcard instead, or on a custom path there.
I know that this isn't good for security reasons, but having the dex/libs accessible without root would be usefull for creating a (sort-of) sandbox.
I'm talking about normal "apk" apps (not just dex files that can be booted with dalvikvm command).
adb install -s will tell the system you want to install the application to the sdcard.
However, I'm not sure this is actually what you want. It creates an encrypted container on the sdcard, so it's not actually accessible in the way that you want.
So essentially, no, it's not possible. For exactly the reason you already mentioned (security).
So, I want to read a very specific file from any connected USB OTG drive. It's a text file that should be stored on a USB stick and I need to read that file, which has a specific name, say myFile.txt. While I understand this kind of getting user input is dumb and not user-friendly, it's what I'm told to implement.
But my problem is, that there are many mount points for USB Drives. on my phone it's /storage/USBStorage1, while on my friend's it's /storage/[HEX_ID]. I tried to get all of them, but it's not possible. in Nexus phones it mounts on /mnt/media_rw/[HEX_ID] which requires root access.
I searched around a little and found SAF, but I didn't find anything on how to use it to open any file without user's direct selection. I don't want the picker to show up. I just want to check if [USB_OTG_PATH]/myFile.txt exists or not, and if it exists I want to read it.
And on a sidenote, do I need to have root acces to read /mnt folders (except media_rw)?
I didn't find anything on how to use it to open any file without user's direct selection
That is because there is no option for this.
I just want to check if [USB_OTG_PATH]/myFile.txt exists or not, and if it exists I want to read it.
That is not supported.
If your file is located in one of the directories returned by getExternalFilesDirs(), getExternalCacheDirs(), and getExternalMediaDirs(), then you can access it directly using normal Java file I/O. However, AFAIK, that directory needs to be created as part of running your app — another developer ran into problems trying to create the directories ahead of time. So, for your use case, this approach is unlikely to be practical, though with luck I am wrong and it proves useful to you.
do I need to have root acces to read /mnt folders (except media_rw)?
In general, yes, though in practice the answer varies by device, Android OS version, etc.
I’m trying to create an app that is able to access and modify a protected database within /data/data/. This process obviously requires root privileges and I am testing this on a rooted device. The general code to access the SQLite database is complete and works against a test database that is located elsewhere (on /sdcard/).
However when I want the application to access the database within /data/data/, it obviously fails as I am trying to access it as a normal user. I have read on the topic of using the su binary on Android for a bit now, and as far as I understand it usually used to execute shell commands only.
So my initial idea of making this work was to simply change the permissions of the file when the application starts, and change it back when it quits. So before actually bothering with implementing that in the application itself, I used my file explorer to change the permission to rw-rw-rw-. However my application was still not able to open the database.
My next idea was to use the sqlite3 program directly from the shell, but I found out, that my ROM does not come with it, so I would have to distribute it myself (Titanium Backup seems to do that).
However there is something that makes me wonder if there might not be a better way: I am using Root Explorer as my file explorer and it has a built-in way to browse any SQLite database. Given that it does not seem to ship with a custom sqlite3 binary, and that my phone does not have one itself, the access seems to happen using the normal Java tools. But how does the app get root rights then?
Is there a way to make an Android application run as root? Or did I forget setting something for the permissions earlier which prevented me from accessing it? Or does anyone know how Root Explorer does it?
You cannot raise the permissions of an already running process as far as I know. The simplest answer would be to copy it somewhere using the root shell / command line edit it, then copy it back as root again. And yes, I did read your question, just didn't explain the answer fully. Hopefully it's clear now. Not sure if root explorer does that or something else, but it would work.
So I want to prevent people from copying files out of my app while it is running.
1) Is there an easier way to detect if files are being copied off my device than through checking if the adb daemon is running?
2) Is there an easy way to enumerate all processes running on the Android OS from an app?
I know Android is not a very secure system, but I would at least like to make it difficult for people to copy files off of my app.
EDIT
To clarify my problem, all the files I have stored on the disk are encrypted. My concern is that I need to unencrpyt these files when accessing them in my app. I am trying to prevent someone from stealing these files while the app is running. I already delete the unencrypted files if someone exits out of the app.
Also, I was focused on adb because I was considering trying to delete unencrypted files if connected by usb. However, I know you can still run adb over wifi on a rooted phone. Now that I think about it, you can probably transfer files over by wifi on a rooted phone as well.
Also, obviously not having the files on the device is not an option.
You seem focused on adb, for unknown reasons.
With respect to internal storage, users cannot copy files off of internal storage of a device using adb, unless the device is rooted. And if the device is rooted, they do not need adb to copy files.
With respect to external storage, that is specifically designed to allow any app, or the user, to copy files from it, again without adb.
Hence, trying to detect adb is pointless.
I know Android is not a very secure system, but I would at least like to make it difficult for people to copy files off of my app.
Then don't put the files on the device in the first place.
I'm not sure if you mean that a user would use your application and put his phone on USB mode and proceed to transfer file off your application folder while your application is still running ?
If some files are needed in order for your application to function at runtime, can't your just make them private to your application ? Like illustrated in this article. Or simply don't put files on the device :)
I'm not sure what "copying files out of my app" means (is your app designed to show/provide files, or are you referring to the resources and other files used by your app).
In any case, you're wasting your time. Android is a very open platform and (particularly on rooted devices) people will always find a way to copy data if they want to.