Commit Graph

38 Commits

Author SHA1 Message Date
topjohnwu
a49002bb2c Reorganize string resources 2019-10-15 03:33:22 -04:00
topjohnwu
5ffb9eaa5b Support loading Magisk Manager from stub on 9.0+
In the effort of preventing apps from crawling APK contents across the
whole installed app list to detect Magisk Manager, the solution here
is to NOT install the actual APK into the system, but instead
dynamically load the full app at runtime by a stub app. The full APK
will be stored in the application's private internal data where
non-root processes cannot read or scan.

The basis of this implementation is the class "AppComponentFactory"
that is introduced in API 28. If assigned, the system framework will
delegate app component instantiation to our custom implementation,
which allows us to do all sorts of crazy stuffs, in our case dynamically
load classes and create objects that does not exist in our APK.

There are a few challenges to achieve our goal though. First, Java
ClassLoaders follow the "delegation pattern", which means class loading
resolution will first be delegated to the parent loader before we get
a chance to do anything. This includes DexClassLoader, which is what
we will be using to load DEX files at runtime. This is a problem
because our stub app and full app share quite a lot of class names.
A custom ClassLoader, DynamicClassLoader, is created to overcome this
issue: it will always load classes in its current dex path before
delegating it to the parent.

Second, all app components (with the exception of runtime
BroadcastReceivers) are required to be declared in AndroidManifest.xml.
The full Magisk Manager has quite a lot of components (including
those from WorkManager and Room). The solution is to copy the complete
AndroidManifest.xml from the full app to the stub, and our
AppComponentFactory is responsible to construct the proper objects or
return dummy implementations in case the full APK isn't downloaded yet.

Third, other than classes, all resources required to run the full app
are also not bundled with the stub APK. We have to call an internal API
`AssetManager.addAssetPath(String)` to add our downloaded full APK into
AssetManager in order to access resources within our full app. That
internal API has existed forever, and is whitelisted from restricted
API access on modern Android versions, so it is pretty safe to use.

Fourth, on the subject of resources, some resources are not just being
used by our app at runtime. Resources such as the app icon, app label,
launch theme, basically everything referred in AndroidManifest.xml,
are used by the system to display the app properly. The system get these
resources via resource IDs and direct loading from the installed APK.
This subset of resources would have to be copied into the stub to make
the app work properly.

Fifth, resource IDs are used all over the place in XMLs and Java code.
The resource IDs in the stub and full app cannot missmatch, or
somewhere, either it be the system or AssetManager, will refer to the
incorrect resource. The full app will have to include all resources in
the stub, and all of them have to be assigned to the exact same IDs in
both APKs. To achieve this, we use AAPT2's "--emit-ids" option to dump
the resource ID mapping when building the stub, and "--stable-ids" when
building the full APK to make sure all overlapping resources in full
and stub are always assigned to the same ID.

Finally, both stub and full app have to work properly independently.
On 9.0+, the stub will have to first launch an Activity to download
the full APK before it can relaunch into the full app. On pre-9.0, the
stub should behave as it always did: download and prompt installation
to upgrade itself to full Magisk Manager. In the full app, the goal
is to introduce minimal intrusion to the code base to make sure this
whole thing is maintainable in the future. Fortunately, the solution
ends up pretty slick: all ContextWrappers in the app will be injected
with custom Contexts. The custom Contexts will return our patched
Resources object and the ClassLoader that loads itself, which will be
DynamicClassLoader in the case of running as a delegate app.
By directly patching the base Context of ContextWrappers (which covers
tons of app components) and in the Koin DI, the effect propagates deep
into every aspect of the code, making this change basically fully
transparent to almost every piece of code in full Magisk Manager.

After this commit, the stub app is able to properly download and launch
the full app, with most basic functionalities working just fine.
Do not expect Magisk Manager upgrades and hiding (repackaging) to
work properly, and some other minor issues might pop up.
This feature is still in the early WIP stages.
2019-10-14 03:49:17 -04:00
Salim B
13a2520ea5 Fix typo and add link to GH issues 2019-09-09 17:39:15 -04:00
topjohnwu
ac9c55dbc1 Add info regarding signing certificates
Close #961
2019-05-01 03:27:06 -04:00
topjohnwu
ab0cc78d2c Update README.md 2019-03-08 10:23:42 -05:00
Aidan Holland
65ebb0d2f8 Misc Formatting
* PEP8 and linting
* empty exceptions
2019-02-11 03:18:15 -05:00
topjohnwu
6ee08b6717 Temporary remove API 16 support 2019-02-03 16:42:16 -05:00
topjohnwu
190cdaddf8 Update README 2018-10-16 02:06:07 -04:00
topjohnwu
2cb198c38c Update README 2018-10-05 17:52:40 -04:00
John Wu
0a4ee3ffc7
Update README.MD 2018-09-21 12:01:59 -04:00
John Wu
37221a508d
Update README.MD 2018-09-09 12:25:22 -04:00
topjohnwu
0f34f0033c Switch to FrankeNDK for building native 2018-08-11 18:46:55 +08:00
topjohnwu
27851bdefa Update README.md 2018-07-28 15:10:06 +08:00
topjohnwu
3fdeb40ddf Update SNET extension dialog interface 2018-07-28 14:56:14 +08:00
topjohnwu
e50192a407 Use standard ANDROID_NDK_HOME instead of ANDROID_NDK 2018-07-12 11:01:01 +08:00
topjohnwu
90d218ebc8 Update SafetyNet extension implementation 2018-06-10 02:35:03 +08:00
topjohnwu
c6d2bf577f Massive building system rewrite 2018-05-13 03:04:40 +08:00
topjohnwu
518c2b0f95 Update README 2018-01-28 04:44:46 +08:00
topjohnwu
deae08fc4b Port zipadjust to Java 2018-01-27 08:25:34 +08:00
topjohnwu
4fd61345af Happy New Year 2018-01-02 01:27:20 +08:00
topjohnwu
e649b0a2df Update README.md 2017-12-04 22:59:29 +08:00
topjohnwu
c6f144d482 Update README.md 2017-12-04 15:21:06 +08:00
topjohnwu
8c6bb383b7 Add support to build with NDK r10e 2017-11-23 23:55:33 +08:00
topjohnwu
e79aa54b70 Proper Windows building support 2017-11-12 04:17:56 +08:00
topjohnwu
a831110816 Add boot signing to installation 2017-10-31 17:05:24 +08:00
topjohnwu
60181c4fcb MagiskManager -> java 2017-10-07 22:48:16 +08:00
topjohnwu
1913125881 Update README.MD 2017-08-20 15:03:26 +08:00
topjohnwu
0b3c078aeb Fix README.MD 2017-08-12 19:17:06 +08:00
topjohnwu
edaf8787d1 Provide external files to Magisk Manager with build script 2017-07-31 00:59:41 +08:00
topjohnwu
b6578b52e3 Update README.MD 2017-06-04 02:55:12 +08:00
topjohnwu
62fe92d922 Update credits 2017-04-28 03:36:16 +08:00
topjohnwu
95fec2100e Use GPL v3 license and update copyright messages 2017-04-22 17:12:54 +08:00
topjohnwu
623a879797 Update scripts 2017-04-22 17:12:54 +08:00
Jan Christian Grünhage
2f33d654e4 Fix Markdown headings 2017-03-26 21:49:24 +08:00
topjohnwu
eea3cb32a5 Add Windows build scripts and fix script bugs 2016-12-06 02:45:51 +08:00
topjohnwu
0ddf4355a1 Update build.sh 2016-11-09 05:16:03 +08:00
topjohnwu
aa54ef10ae Magisk Hide: Unmount everything 2016-10-06 17:53:52 +08:00
topjohnwu
88a97319cc Add zip static files 2016-09-14 10:31:13 +08:00