[APP] Seeking Help To Rev Engineer My Own App - Android General

First I want to make this clear right from the start that I am the developer/author of the app I am wanting to reverse engineer. There is nothing illegal or questionable about my intentions.
If I have posted this in the wrong section I do apologize and would ask that it be moved to the appropriate section.
Before I go into any specifics of what the app does or what it is used for; the reason why I am wanting to reverse engineer the apk back into source code has a somewhat unique origin that very few people will ever encounter. About 4 years ago I began development on my app that is now known as Ls Droid. I did not know any Java code and I had an idea at the time that lead me to find a development tool created by MIT that was known as App Inventor 2. If you've never heard of this before, App Inventor is a GUI based programming language based on Googles Blocky that allows the user to combine various types of blocks that each represent different code functions and create working Android apps. I'm not going to discuss how App Inventor works but you can read the overview of it at appinventor.mit.edu/ . Over time my app outgrew what MIT's version of App Inventor was capable of and I moved my app to another platform(Thunkable) that was still based on App Inventor but greatly expanded on it's functionality and was capable of dealing with larger projects than what the MIT servers would allow. I used Thunkable for several years and ran my app though it's entire Alpha development life cycle and into an open Beta. Unfortunately Thunkable had been creating their own(improved) version of App Inventor from the ground up and not only was it incompatible with app's created on the App Inventor platform but they did not include many of the things my app required to work and I was forced to look for another platform to move my app to in order to continue development. Unfortunately by this point all of the spin off versions of the original MIT App Inventor had created advertising components and the majority of people using these GUI based programming platforms were now focused on creating earning apps. As a result the people running spin off versions of App inventor are now focused on providing tools based around add based apps and less interested in fixing basic functionality for core components as they are rarely used in earning app.
So this brings me to my current situation. The compiler used by the current GUI programming platform I have been using for the last 8 months or so has become unreliable and buggy. Core functionality of how specific blocks function has also been altered several times in the last 6 months and each time a change like this is made requires dozens of hours to restructure my apps logic to work with the new changes. I have tried to leave these GUI based programming platforms several times and move my app into Android Studio but have never been successful. Attempting to recreate my app from scratch in Android Studio would be a massive undertaking even for someone fluent in Java and I only have a basic understanding of Java at best. I can however work from existing code and alter or restructure it with out a lot of trouble and that's basically all I need to do in my app at this point.
I have worked with a number of people in the past who have tried to help me turn an APK back into source code that worked in Android Studio and about a year and a half ago I was working with someone who was able to decompile the app and successfully import it into Android Studio where it did mostly work with the emulator. Unfortunately this person was killed in a car accident, I do have a copy of what they had done that was close to a working version but I was never able to get a copy of the source they had working in Android Studio. I have had a couple of other people look at this code since then but no one else was able to do anything with it. At this point the version that was being worked on that did open in Android Studio is old enough that it bears very little resemblance to the current version of the app and attempting to even work from this code now would be a massive step backwards.
In the past I have always looked for help from automotive reverse engineering forums since my app has a very unique purpose, it is used to read and write the binary code from an engine's computer on a number of General Motors vehicles that are popular/common in the hot rod community using a Bluetooth tool connected to the vehicles OBD II data port. I created this app to remove the cost barrier that had previously been required when you wanted to make changes to an engines program on fuel injected vehicles....my app is free and uses a relatively cheap OBD II tool. There are thousands of people that have used my app over the last couple of years and successfully re-tuned their vehicle with many of these people being able to do this with no cost out of pocket as they already had the tool my app was designed to work with.
My app is now at the point where even making basic changes or bug fixes is becoming an issue due to constant changes in the GUI based programming language. I have exhausted the help of various automotive community's, mixing smart phones and cars was a long shot in the first place and here I am 4 years later with a very successful app but it's well beyond what my network of car hacking colleges are able help me with. It's no secret that XDA has some of the best Android developers(and hackers) anywhere on the web so I figured this would be the best place to turn to for help.
Maybe this would be fun for someone here? I doubt people get a chance to decompile and reconstruct an app legally....and if they do it's extremely unlikely it was done on an app built with a program like App Inventor. I have no issues making my apps source code public so I have no issues discussing anything to do with this publicly, but if someone would prefer to discuss this by PM or Email I'm fine with that as well.
My app can be found at ls-droid . com near the top of the page, there are a couple of versions posted currently with 2.2B being the last public release but it's not exactly current. I do not want to post the APK for the most recent version of the app I have been working on at the moment on the off chance someone wanting to use the app were to find it since it has some pretty nasty bugs right now due to compiler changes. You can search Youtube or Facebook and should have no trouble finding information on my app if your wondering how it works.

Related

mod of delicious app to handle pinboard.in?

I bought a copy of Andricious some time ago and I adore it. My entire
life is structured around my del.icio.us bookmarks, and having such easy
and well organized access on my phone has been wonderful. I can't tell you how many times I have looked at an app on the market and thought, "Why do I need this? The same information is two clicks away via andricious."
However, as you have probably heard (the screams of despair), delicious iѕ being shut down by yahoo.
There are a few projects out there which are compatible with the delicious v1 api. The most popular that I know of is pinboard.in. Scuttle and del.irio.us/rubric are open source variants, though they aren't as actively developed now as they once were.
Would it be at all possible to make the api url in any of the android del.icio.us apps a configuration option, so that users migrating to compatible services can still make use of the del.icio.us apps currently available?
I just published a port of my Delicious app for pinboard in the market.
XDA Thread
Project Site

[Q] Please help Developing an Android Map App for a company as part of a project

Hi I'm Mark a Web development student in my final year.
Basically for my final project were working with an external company that want stuff done for free or very close, this includes an android app.
The app im going to try to make will be private for the company to give out locations using google maps and gps/geolocation.
The app will be distributed through the site we are developing to certain users and not featured on the marketplace due to privacy issues.
Problem is I've never developed for android or any mobile platforms and have an extremely basic knowledge of Java but i mainly develop for web and windows using c# so naturally I have a few questions for people with experience in android development.
1. Is it possible to have the app powered by google maps?
2. Any suggestions of how one user will be able to upload gps coordinates to this app?
3. Rough idea of how long it would take e.g. few hours, few days, few months?
4. Overall is it possible, any problems I might run into?
5 Any Advice, tips,or better suggestions?
Thanks a lot for reading this far, any answers or help would be greatly appreciated.

Cydia Substrate — Native (or Java) Runtime Code Modification

Cydia Substrate is a code modification platform. It can modify the code of any major process, whether that code is written in Java or C/C++. It has been designed to support an ecosystem where many developers are interested in hooking the same processes. It is designed to be powerful and efficient.
== How do I get Substrate? ==
You can either download it from the Play Store or directly from its website.
== How do I develop for Substrate? ==
You download its SDK using the Android SDK manager or from its website. There is extensive documentation on the website.
== What is Substrate's website? ==
http://www.cydiasubstrate.com/
== How is this different from Xposed? ==
Many compare it with Xposed, but Xposed only supports a single use case: hooking Java functions inside of app_process. Substrate can hook native code, such as is required to modify the way styles are loaded inside of the Android asset manager. There are many other differences, however, as Substrate's API is based on five years of experience managing a community of runtime code modification for iOS. I normally avoid doing direct comparisons, but after attending Big Android BBQ and presenting on Substrate, I have been encouraged to make the differences and advantages of Substrate's approach more explicit here on XDA.
Xposed requires an inverted form of logic based on "before" or "after" hooks while Substrate lets the developer use more straightforward "replace and call previous" implementations. This also enables more complex interactions with the previous implementation that have been shown to be valuable among the thousands of developers using Substrate on other platforms. Xposed attempts to offer something similar with "replace" hooks, but those do not provide access to the previous implementation, and while Xposed provides a way to call the "original" implementation, that skips any other hooks that might be stacked.
Xposed requires the developer to find a safe moment to interact with the class being hooked. To make this possible, there are numerous lifecycle events such as "VM loaded", "package loaded", and "command line application started". However, this does not solve the problem that touching classes can change the order in which they statically initialize. This also means that it will not be possible to provide declarative syntax wrappers (such as Logos, which developers use on iOS) on top of Xposed, as this context will have to be made implicit in imperative logic. Substrate solves this class initialization problem by allowing developers to hook the classloader itself, getting a callback when a class is "linked" so that the developer can find a class loaded in any classloader (even as a plugin to an application an hour after that application starts, where the code is downloaded as a .dex from the Internet).
Xposed has a method hook implementation that makes it lose track of which method was hooked, requiring it to do a lookup every time such a method is called. This implementation is currently linear in the number of hooks, making it slow down the more hooks you install. Worse, there is a high constant multiplier on this algorithm, as the comparison between entries is very expensive (and was made more expensive when recently fixing a longstanding bug caused by this lookup being slightly incorrect). Substrate, in comparison, uses runtime code generation to avoid the need to every look anything up at runtime: you can use Substrate to hook small functions in tight loops without experiencing the same kind of performance issues you would see with Xposed.
Substrate is also designed with a different user focus: while it currently has a setup interface, it would prefer to not have any UI at all (and this will be strived for in subsequent versions, assuming anyone cares to use it). Upgrades to Substrate can be automatically installed by the Play Store and do not require the user to interact with Substrate for the changes to "stick". Substrate itself is distributed via Play. Rather than confine these kinds of modifications to advanced users who use forums such as XDA, the idea is that everyone should have access to using this kind of technology. If you have a ROM or another store in which you'd like to see Substrate distributed, I would be more than happy to talk to you about this to make that happen, and these installations will be fully supported.
For some more information on the differences between Xposed and Substrate (or if you are wondering why you should bother paying any attention to things that I say, as maybe you don't remember me from my earlier Android projects), I encourage you to read the comments I left a couple posts down from here on this thread that describe the history of Substrate, how I fit into the Android ecosystem, and more about how Substrate differs from Xposed. I will also likely be posting the talk I gave at Big Android BBQ (with either notes to go along with each slide or in the form of a video I will record re-giving the talk and advancing the slides), which might make some of these things more clear.
Current Changelog
[this is the changelog from Play, which has been compressed slightly. I will bring the more full changelog back, as I have it saved somewhere, and put it here or link it here]
v0.9.4011:
* fix decoder bug inside ARM emulator
* support Genymotion Intel emulator
* add symbol names for Moto X
v0.9.4010: critical Android 4.3 fix, avoid old Superuser bug
^^ must install before Android 4.3 OTA!
v0.9.4009: work around Xposed bug, 4.2 fix, better errors
v0.9.4008: HTC linker path patch, limit symbol exports
v0.9.4007: RAZR i 4.1.2, detect HTC override, avoid ps
v0.9.4005: incompatibility detector, avoid mount/ln/mkdir
v0.9.4004: Holo, Script Failure, detect physical /vendor
Comments from Developer
So, yeah: I'm the developer of Cydia Substrate, the framework everyone uses on iOS to do runtime code modification. Back in 2011, I gave a talk at Android Open along with a demo of Substrate running on Android 3.0. However, after some in-depth discussions with people there who were interested, I realized that what I had at the time "wasn't sufficient": it was just the core of an implementation, not an end-to-end offering. By the time it had everything I felt it needed to launch--including a comprehensive website filled with documentation, a configuration application to install with it, fully tested support for both ARM and x86, a forward-compatible pure Java API vetted by a bunch of the top people in the iOS modding community (as I feel like breaking APIs after launch is one of the more evil things a framework can do), and an extension that would make sense to end users that they could try (so that trade press wouldn't be horribly confused, as I knew they would report on the release)--it was already 2013.
http://www.youtube.com/watch?v=tA9cnemnQ0A <- Android Open 2011 keynote teaser
As many people then know, I released it in June. A lot of people have tried it (165k installs just from Play, and another 20k downloads of the APK off the site), and many of those people even like it enough to keep it installed and leave positive reviews, despite there being almost nothing available to use with it except WinterBoard (which I really only did as a demonstration). However, I also get comments from people who seem to believe I'm some kind of "interloper" in the world of Android. Additionally, there are the people who leave reviews saying stuff like "this is stupid, we already have Xposed" (sometimes then explicitly adding in the "go home to iOS" kind of spiel). The #1 complaint, however, is "nothing I can do with it", because developers never seem to talk about it or use it much, and the people installing it are all end users. Clearly this isn't the kind of reaction that I thought would happen, especially after having discussed Substrate at length with pulser_g2 before launch (who said that the community here tends to be very good about judging things on their usefulness and technical merits as opposed to having emotional attachments).
http://www.cydiasubstrate.com/ <- Cydia Substrate
Given this, and after an encouraging back/forth I had with some people on reddit's Android subreddit a few days ago in some threads about the analysis I did of that recent Android iMessage client (people who didn't know much about the ways in which Substrate is very different than Xposed in capability and focus), I figured I'd finally make a post on XDA. I kind of had been waiting to make this post as well, honestly (as again: I like things to be more perfect before I release them than maybe people are used to around here ;P), but it seems like I'm now waiting for something that is itself causing the delay (I had really expected to do this in July, before the whole thing got more actively depressing). This is clearly that post ;P. I've responded to a bunch of other threads here talking about Substrate (and the many other Android projects I've released) in the past, but this is the first time I've actually started a thread.
(In specific, Substrate currently doesn't support some Samsung devices due to a change they make to the linker paths, and I wanted to have 100% device coverage before making the inaugural XDA post. However, I'm finding it very demotivating to spend the time to think through all the options I've been considering for workarounds given the overall lackluster reaction to my work, so I'm not even making fast progress anymore: I tend to work on the things that people react positively to, and while I got a lot of positive reactions on the balance from users, I got much less than I expected from developers given how many people use Substrate on iOS and how powerful the framework is. I think, from some conversations I've had, this is largely due to confusion over how Substrate on Android relates to Xposed, which many people seem to think of as the "home-town competitor" "that does the same thing". I thereby figure that I may as well attempt to directly address that core motivation problem, to see if I should even bother continuing spending time helping out in this community, hence this ludicrously long and highly personal post about what is essentially a technical framework ;P.)
[Readers who find the next section boring should skip below to "=== Substrate ===".]
I imagine I (sadly) thereby need to start by defending my history in the Android community, as many people seem to not be aware of much of it; it actually goes back very far, as I had promised the overall mobile community that if Android were ever rooted, I'd immediately start looking at it in earnest (before there was a device, I had already been messing around with the emulator, but the device concepts Google had at the time were more like slightly souped-up feature phones, not competitors to something like an iPhone). So, in 2008, when that first "root console attached to keyboard" mistake was found on the G1 that let you get a root telnetd running by just typing it into any search field, I dropped everything and drove two hours to Los Angeles to pick up a G1 (they were not selling them in Santa Barbara yet, due to T-Mobile not really having a presence here at the time). As promised, I immediately set to work attempting to help out.
As I ran a number of mailing lists already for iOS, I set one up for Android called g1-hackers, which attracted a good number of people, and even a few Google employees who worked on bionic and the kernel. On this list is where the G1's bootloader was first dumped: if you've ever heard the stories about Eddie Dost figuring out how to do it, this is that. In fact, it was from my G1, with a kernel I compiled (following Eddie's direction: I did not know much about flash drivers), that that first Android NAND was obtained (as Eddie had already updated his device and thereby didn't actually have root). Here is a link to the mailing list thread, directly to the post where we finally succeeded and I provided the kernel image I used so that others could perform the same dump on their own devices.
http://www.telesphoreo.org/pipermail/g1-hackers/2008-December/000096.html <- [g1-hackers] G1 boot code
Around that same time, I was also contributing to AOSP, providing a bunch of patches to things like mount and init, as I wanted to be able to get Android devices to a state where they could run something much closer to Debian than Android (I had my eyes set on kind of a hybrid). In the process of doing this, I wrote a guide that for a couple years subsequent were the canonical instructions for getting a bootstrapped build of Debian installed as a chroot under Android. At the time the patch turnaround on AOSP was sometimes over half a year (and almost never shorter than a couple months), which made contributing to the project sufficiently painful that I eventually stopped. If you search through Android's codebase, though, you still find some of my work.
http://www.saurik.com/id/10 <- Debian & Android Together on G1
At the time, I honestly do not remember XDA having yet become "the place" where people spent much time talking about Android: instead, a lot of conversation happened on IRC (which is where the iOS community had already been, and where it remains). There was a channel that I was a part of which included a bunch of people whose names would hopefully be familiar to people around here, including JesusFreke (and, much later, Cyanogen). I got to see the birth of a lot of great websites and tools (such as JesusFreke's smali/baksmali) while participating on that channel. Apparently, I was talking about "Substrate for Dalvik" on that channel in November of 2008 (which is also when I first joined XDA): that's how long I've been staring at this ;P.
During the next couple years, I ended up developing and maintaining a website called Cyrket, which had the mission to allow developers and users to search the contents of the Android Market using their desktop web browser. It also solved a few key problems that developers had with comments, in that you could only see comments for apps your device had access to that were then written in your language. Developers without devices, or with devices that could not see their product (which often included those that paid extra for the ADP1, which could not see copy-protected apps) could not see comments at all. Cyrket presented all of the comments for your application in all regions in all languages (and even used Google Translate to translate them all into your own language).
The way Cyrket had worked is that I scraped the contents of the Market using the same protocol Google's client used, indexed it (supporting find-as-you-type search), and exported it all to the site (well, originally, it was actually just a live client, but then it got really popular ;P). It got me into some mild trouble occasionally with the Android Market team, but overall no one seemed to mind it that much. Cyrket was actually the primary site people used for this purpose for a long time, and I even got the impression that people at Google were begrudgingly using it as it was more convenient than the alternatives. There were a few times where it had to be taken offline (due to changes and rate limits from Google), one time for months, but I'd usually figure out some new way to get it running. Honestly, though: I was really glad when Google finally launched a website for the Market and I was able to stop working on Cyrket ;P (and also glad that Google added most of Cyrket's features for developers to their publishing console, features that Apple actually still doesn't have AFAIK).
http://www.androidtapp.com/cyrket-android-market-browser-back-from-awol/ <- Cyrket Android Market Browser Back from AWOL!
Since those times, I mostly felt the need to get Substrate "awesome" (which started to really come together during 2011, after Cyrket was no longer needed), and so didn't do many larger projects on Android until recently. That said, I have been involved in things related to exploits and security. One of the higher impact things that I did was to release mempodroid, an implementation of the mempodipper exploit described by Jason A. Donenfeld for Linux 2.6.39+, which became the primary method to root devices running Android versions 4.0.0 through 4.0.2. Much more recently, users have been using Impactor, my implementation of the various "Master Key" exploits (based both on bugs described by Jeff Forristal as well as techniques I pioneered against a random AOSP bug).
https://github.com/saurik/mempodroid <- mempodroid README
http://www.saurik.com/id/17 <- Exploit (& Fix) Android "Master Key"
Given all of this, I hope people can get a feeling for just how strange and depressing it feels to me when people seem to suddenly believe I'm some kind of foreign invader . (FWIW, I also feel rather awkward having to describe all of this in this fashion, but frankly I'm at a point where I'm realizing that if I don't explain it in this much detail myself, no one else will. While I'm certain I'll get some people responding really negatively with comments like "he's such a blowhard, going on and on about silly little things he did", so far when I've given similar spiels to people in person at conferences, they often go "oh wow, I remember that tool/happening, but didn't remember that that was also you", and so figure that this might go a long way to fixing this weird problem: I'm not just "that iOS jailbreak guy".)
=== Substrate ===
Alright, now with that aside: in time for Google I/O (which was arguably bad timing, as I was then immediately unavailable for days ;P), I finally released Substrate. Substrate (in my clearly biased opinion ;P) is actually really cool: as far as I know, it is currently the only tool available for Android that allows developers to easily modify native code without patching/replacing. I know, for example, that people often ask how to modify features like the holo themes that are implemented in C, and the answer is Substrate: if you can find the code (which is often exposed via a symbol as there are tons of C++ symbols available on most Android builds) you can use Substrate to hook it at runtime in a way that avoids having to patch the files on disk, allows developers to deploy their changes across multiple ROMs, and supports the idea that users should be in charge of the specific features that they have on their devices (as opposed to ROM distributions).
As another concrete example that maybe makes this more obvious: sometimes you download a program from the Play Store (which, incidentally, I have a very hard time not constantly still calling the Android Market ;P) that is pretty much just a massive JNI binary--maybe an OpenGL game or a media player of some sort--that refuses to run on a device that has been rooted. A really common way that developers implement such checks is to do things like verify the existence of files on disk. The simple/common checks are very easy to detect and defeat using Substrate as you can hook the native "open" call from the C standard library, check if the filename is something like /system/xbin/su, and return "nope, not there".
http://www.cydiasubstrate.com/api/c/MSHookFunction/ <- MSHookFunction()
Substrate lets you do this kind of hooking in any system daemon (not just those spawed via app_process). Yes: if there's a program running in the background of your phone, some native service written by the OEM that manufactured the device, you can use Substrate to modify it. A lot of very interesting extensions on iOS involve these kinds of hack; for an extreme example, the software unlocks that we used to have for earlier iPhones involved modifying CommCenter, a native program that initializes the radio hardware: by hooking some of the code in that daemon, it was possible to, at just the right moment, inject a different command sequence over the serial connection to the baseband, exploiting it for the unlock.
http://www.cydiasubstrate.com/inject/android/ <- Android Native Injection
Of course, Substrate also supports hooking Java code (yes, a little like Xposed, which at some level uses the same underlying trick I walked people through in my talk at Android Open 2011). Somehow, though, a lot of developers don't seem to catch all that other stuff that Substrate lets you do, and get hung up on this one part that Xposed also manages, leading to all those aforementioned irritating comments about how "there's no point to Substrate because we already have Xposed": Xposed can't do most of the things Substrate can do (and the developer has even told me that he actively tries to avoid Substrate-like techniques as they are "pretty complicated", so it isn't even moving in that direction). FWIW, on iOS it took a lot of time for Substrate to get these features (it did not have them in 2008 when I first released it): they aren't trivial ;P.
http://www.cydiasubstrate.com/api/java/MS.hookMethod/ <- MS.hookMethod()
Even within the restricted context of modifications to Java, however, I think Substrate has a lot to offer. Again: I actively refused to release Substrate until I felt I had truly nailed a few things, including in particular the Java API (at Android Open 2011, I only supported JNI, which developers there told me would not lead to traction). I was a major proponent of aspect-oriented programming when I was younger, I got into byte-code engineering in college, and I co-published a paper on a Java code modification framework called jMonitor in 2004: this is something I've been thinking about for a long time, and I think the approach I take has some merit in and of itself. I know a lot more can be done (I feel it would be really interesting to have AspectJ-style pointcuts, for example, or the kind of bytecode-level instruction matching that I implemented as part of jMonitor <- features not described in the paper, I think ;P), but I felt a good first step was be to directly leverage the iOS community's six years of experience.
http://www.cydiasubstrate.com/id/6dfa187d-6e04-4f97-b63a-ae75b5338e01/ <- jMonitor [RV '04]
To this end, Substrate provides an API for Java that is very analogous to the API that it provides for modifying C/C++ and Objective-C. The focus is on "I know about some code and I want to modify it", allowing you to not have to think much about the timing or execution details of the program that may be loading that code (so you never have to think about "packages" or "processes" or "applications": you just concentrate on "classes", and thereby don't need a million "helper APIs" to handle each narrow timing case). To enable this, I use the aforementioned ability of Substrate to modify native code to hack features into the VM itself, giving me the ability to instrument events like "a class has been loaded". If you want to hook a method of a class from Apache Commons, and you want to hook that class no matter whether it was loaded as part of an application or dynamically as part of a classloader for a plugin downloaded by an application, this is trivial to express with Substrate. AFAIK, that use case isn't even describable using Xposed.
http://www.cydiasubstrate.com/api/java/MS.hookClassLoad/ <- MS.hookClassLoad()
This kind of VM-level modification and runtime code generation support (that is heavily flexed on iOS Substrate, and thereby has had years of in-the-field testing; so far Android has exposed just one bug in its ARM reassembler after release, and that was only in the qemu emulator for some reason) also means that Substrate's implementation of hooks is highly efficient: to compare again to Xposed, every time a method that has been hooked is called via Xposed, there is a linear-time search through a linked list doing a rather heavyweight comparison to determine which method it was after the fact; with Substrate, every call is direct, there are no lookups, and there are no comparisons, so you can hook an arbitrary number of methods with no slow down, so even very small methods that are called very often can be hooked without issue.
Additionally, with Substrate I wanted to address a specific pain point that many people would bring up when I'd give talks: "how is this secure, and how do I control what apps can use these features". This became even more important, as I wanted Substrate extensions on Android to be easily deployable via conventional means, such as the Play Store (yes: Cydia Substrate itself is in the Play Store, as I believe it is important for these kinds of features to not just be in the hands of developers on forums, but to be used by end users everywhere). To this end, I integrate into the Android security model, providing a special permission that applications must have to install a Substrate extension. This helps enable the idea that Substrate mostly "gets out of the way", becoming more of a technical detail behind your extension rather than something users will need to interact with constantly to activate or update your product.
I also wanted to provide at least something that would help solve the "reflection hell" that developers seem to always find themselves in while attempting to do runtime code modification in Java (even back on desktop Java using AspectJ). I thereby provide the means to "bless" a class loader, allowing it to access private fields and classes without the overhead of reflection: the access checks, for just that one class loader, no longer apply. Substrate extensions are loaded into such a "blessed" classloader. (I do not, even though I could, ever just whack an access check VM-wide; Xposed does this, and I feel like it is going to have security implications on Java security contexts applied to class loaders for plugins.) In the case of WinterBoard, for example, I don't ever have to deal with invoking Methods or getting Fields: setAccessible is just a dim memory.
Being able to use this functionality, however, can be awkward, and in some cases is almost impossible: while testing this feature, I realized that developers would end up needing "public stubs" for all the classes they were working with, but the calling convention for a public method and a private one is different, so the calls fail at runtime. I thereby ship as part of the Substrate SDK (yes, there's an easily-updated SDK package that you can download using the Android SDK Manager ;P) an extension to javac itself (as you might imagine at this point, written using AspectJ) that turns off access control checks: you can thereby access private fields or call private methods with no extra work both during development and at runtime. This all works sufficiently well that I generally run all of ant under the modification, such that anything ant compiles becomes "blessed".
http://www.cydiasubstrate.com/id/c17c554f-b603-4e3b-8f99-ebb3528e3ef8/ <- Java Access Controls
(And yes: this is one of the things that caused Substrate to get delayed even longer than it already had been. There was also a rather serious delay caused by my attempts to really nail the boundary between "code that is shipped with Substrate" and "code that is shipped with the extension", something that burned me a lot throughout 2013 as it was the kind of problem that spending time actively thinking about didn't directly help, requiring an epiphany I had soon before Google I/O. Arguably had I been willing to ship without documentation at all, and had I generally cared less, I would probably have had everything out in very early 2012, but during January-May I started working on the initial draft of cydiasubstrate.com, as I had apparently incorrectly thought that such efforts would be critical to developer adoption.)
Again, I write this in the hope that it clears up misconceptions, either about myself or about Substrate. As far as I can tell, Substrate has a lot of very unique value propositions: things that currently are only made possible by Substrate; and, even within the restricted scope of hooking Java code inside of a service being managed by Zygote (the only area of overlap with Xposed), I think that it offers a bunch of advantages in security, performance, deployment, and ease of development that cannot be so casually dismissed with a flippant "we already have Xposed (go home)". A lot of these features (and I haven't even gone into all of them: I could write paragraphs about the advantages of how Substrate's API handles chained hooks, the ways I enable extensions that need to cross classloader boundaries, or the way Substrate makes it easy for end users to temporarily disable extensions without complex tooling) come from having spent over a decade now thinking about this problem and the last five years actively managing a developer ecosystem with tens of millions of users on iOS.
I am thereby happy to answer any questions about how to use Substrate, issues with Substrate on any device (I never blame the device: I might not have a fix immediately for a specific problem, but I always consider it Substrate's job to work around issues the device throws at it to get its functionality in place so the task will at least end up on my todo list), or even about me (as a lot of why I find writing this both so important and so painful are due to the occasional-yet-present more-personal attacks/misconceptions I often seem to receive about somehow being an "outsider"). (That said, please do have some patience: sometimes my ravenous need to do nearly 24/7 testing on a specific device has to give way so I can go to a conference I'm giving a talk at, or so I can focus on a different problem that might be more pressing or simply have a higher probability of near-term success: spending an infinite amount of time on one problem is unfair to all of the other problems that exist ;P.) [And, in fact, I have a meeting I have to be at tonight, but which hopefully won't take insanely long.]
Reserved Post
["reserved", as apparently you always should have at least one of these ;P]
Links to Extension Threads
[and finally, I can see ending up with a page that might link to other threads on XDA, although arguably I should put this on cydiasubstrate.com. right now, most projects that use Substrate are in Play. I am not certain if I'm now just misunderstanding how to use XDA, though: again, this is my first thread I've started myself]
Wow. The timing couldn't be any more perfect for you to post this.
I do not have an Android device yet and have been theorizing exactly how I could easily make modifications to applications.
Because I am just getting started in the Android development community, I don't have any biases towards one framework or the other.
Sooo.... this is on my watch list.
gugbot said:
Wow. The timing couldn't be any more perfect for you to post this.
Click to expand...
Click to collapse
The opinion of many (reasonable) people differ ;P.
gugbot said:
Sooo.... this is on my watch list.
Click to expand...
Click to collapse
Yay! If you have a moment, I'm curious: how/why did you find this thread? It seems like very few people actually go to this "Frameworks" sub-forum; there are almost no threads posted to it except the one about Xposed, which I'm presuming people must be finding by links from other places (whether random websites or other threads on XDA).
saurik said:
The opinion of many (reasonable) people differ ;P.
Yay! If you have a moment, I'm curious: how/why did you find this thread? It seems like very few people actually go to this "Frameworks" sub-forum; there are almost no threads posted to it except the one about Xposed, which I'm presuming people must be finding by links from other places (whether random websites or other threads on XDA).
Click to expand...
Click to collapse
I was browsing in development tools and was surprised to see that a Saurik posted about Cydia Substrate!
I was brought to this forum by one about theme development?... Maybe you should post this in a forum with more traffic. There seems to be an endless amount of categories for everything.
i have try your cydia substrate on cm10.1.3 stable..device samsung i9300..
install winterboard..apply icon pack but icon pack not applied..
then when want to open other apps the apps fc..except winterboard..
slipar said:
i have try your cydia substrate on cm10.1.3 stable..device samsung i9300..
install winterboard..apply icon pack but icon pack not applied..
then when want to open other apps the apps fc..except winterboard..
Click to expand...
Click to collapse
Yeah, as I mention in this thread WinterBoard was more of a demo that has been difficult to justify improvements to . This isn't an issue with Substrate, at least.
Would you mind sending me the crash report from the adb log? At least, would you mind telling me the name of the theme you applied? Also, thinking about it, CyanogenMod already has a theme engine... it never occurred to me how WinterBoard would interact with the existing theme engine in CyanogenMod (although I guess thinking even longer about it, I see no reason why it would fail horribly... it should just layer on top).
saurik said:
Yeah, as I mention in this thread WinterBoard was more of a demo that has been difficult to justify improvements to . This isn't an issue with Substrate, at least.
Would you mind sending me the crash report from the adb log? At least, would you mind telling me the name of the theme you applied? Also, thinking about it, CyanogenMod already has a theme engine... it never occurred to me how WinterBoard would interact with the existing theme engine in CyanogenMod (although I guess thinking even longer about it, I see no reason why it would fail horribly... it should just layer on top).
Click to expand...
Click to collapse
hope i send u the correct logcat..
im using ios7 concept theme..g play link here
slipar said:
hope i send u the correct logcat..
im using ios7 concept theme..g play link here
Click to expand...
Click to collapse
Thank you so much for the information. Here is a new version of WinterBoard that seems to work with this theme.
http://cache.saurik.com/apks/com.saurik.winterboard_0.9.3922.apk
thanx saurik..tested but this time winterboard just fc when try to change theme..
logcat attach..
slipar said:
thanx saurik..tested but this time winterboard just fc when try to change theme..
logcat attach..
Click to expand...
Click to collapse
I'm sorry about that issue... this is actually quite interesting to me as it might indicate that I need to do some more work on the blessed compiler as it relates to miranda methods. I had verified that the theme functioned, but had not gone back to attempt to re-verify the setup activity itself, which I guess hadn't been recompiled in a long time. I've added a temporary workaround to the issue while I investigate further. ("Humorously", if you have Xposed installed, I am pretty certain that the WinterBoard settings activity would have worked, as Xposed just destroys the access control checks for the entire VM.)
http://test.saurik.com/xda/com.saurik.winterboard_0.9.3922+1.gf733f01.apk
Hey there, I just happened upon this thread while deeply perusing the boards after just getting home from a 17hr drive and being unable to go to sleep yet. I am VERY interested in the substrates capabilities, it sounds like a very interesting concept. I am a new developer and am wanting to learn more and play more....I use xposed on my phone now and was considering starting to develop modules for it, buuuttt I think I just changed my mind I'm on an att sgs4 running a 4.3ge Rom. Going to install the substrate the night via Play Store and mess around with it starting tomorrow. Thanks for this
Sent from my GT-I9505G using Tapatalk
Sc4ryB3ar said:
I'm on an att sgs4 running a 4.3ge Rom. Going to install the substrate the night via Play Store and mess around with it starting tomorrow. Thanks for this
Click to expand...
Click to collapse
Yay! (Now, watch your GT-I9505G be one of those few Samsung devices Substrate detects as incompatible ;P. Samsung has so many model numbers that all map to the same high-level marketing names that it's difficult to keep track of what's what. If that happens, and you are interested in helping out, I can implement one of my alternative injectors quickly for you to work with.)
saurik said:
Yay! (Now, watch your GT-I9505G be one of those few Samsung devices Substrate detects as incompatible ;P. Samsung has so many model numbers that all map to the same high-level marketing names that it's difficult to keep track of what's what. If that happens, and you are interested in helping out, I can implement one of my alternative injectors quickly for you to work with.)
Click to expand...
Click to collapse
It installed just fine, quickly and with no apparent issues
winterboard, however rendered neither theme I chose correctly, wondering if its the themes though.... Didn't get a logcat and then I hosed my system last night messing around too much, so I started fresh and haven't gotten back to substrate and wb yet....I'll be back to it withing a couple of hours
Sent from my GT-I9505G using Tapatalk
substrate source code
Saurik,
I've been dabbling some with Cydia Substrate and it seems to offer a lot of unique possibilities for Android apps.
Do you have any plans to release the source code for this like you did on iOS? I'd be very curious to learn more about how it works. Also, is there a link to your talk from the Android Open conference?
Thanks,
Fred
(Ugh. I have no clue how people keep up with a forum, especially with the website as slow to load every page as it is ;P.)
fjones8856 said:
Do you have any plans to release the source code for this like you did on iOS? I'd be very curious to learn more about how it works.
Click to expand...
Click to collapse
I currently do have an intention to release the source code, but I'm not certain under what license (all of the licenses I normally use don't solve the specific issues related to Substrate). That said, no one seems to care much about Substrate on Android: on iOS people tend to (almost to a level of it being a problem) jump on new solutions to evaluate constantly, whereas on Android people seem to just snark "we already have X" even when there are compelling advantages to a replacement. Given this situation, I am highly unmotivated to spend the time to figure out the right solution, given that in a way Substrate is "my magnum opus": it is the culmination of the research and experience of so many years of my life, that passing up the ability to license it to the companies that sometimes talk to me about that (for either enterprise wrapping or security) to satisfy a group of people who are mostly asking for the source code specifically to replicate the technique *and then avoid using Substrate*, makes very little sense.
On the project side of it, Substrate on iOS only ever received a single code contribution from someone I wasn't already so close with that I was sharing code already. It isn't even the kind of project that one would expect getting many contributions: it is more of a backend technology, and the extent to which it has a GUI is actually a bug (I intend for it to be 100% seamless as part apps that use it: Substrate on iOS does not have a GUI and never will have a GUI, and that's how I think it really should work on Android as well, but of course right now I need the silly Install button). If anything, on iOS, we often end up with random companies that want to "own the scene", which ends up with them forking Substrate in ways that cause platform incompatibilities for other developers: Substrate on iOS has thereby actually been closed source now for almost two years, and it has actually improved the stability of the platform. I thereby am somewhat loath to "repeat the same mistakes from before" and end up with forks.
fjones8856 said:
Also, is there a link to your talk from the Android Open conference?
Click to expand...
Click to collapse
There was no recording of the actual talk, just of the keynote introduction that I already link to from my website. In the talk I walked people through a demonstration of using an early version of the JNI-level Substrate API, and showed how it worked (which was very simple at the time). In essence, I demonstrated, with my exact code on the projection, the technique that Xposed started using half a year later (which is just "oh, I'll change the contents of this Method object, as apparently the runtime doesn't care if the Method is allocated as part of a Class; if I do it right I can simulate registerNatives") and the most obvious way of implementing MSJavaHookClassLoad (which--for the really really low-level API I had at the time, on pre-4.0 VMs that didn't have complex JNI stacks--is clearly "MSHookFunction the class load and provide a callback"). Everything is going to be new for ART, though: the techniques are going to have to be much more sophisticated (which I'm excited by, as this is a game changer).
Pm sent
Sent from my GT-I9505G using Tapatalk

Samsung Gear S2 App Development

I'm new to the Tizen world of development. From what I've been hearing, Tizen is so difficult to program for that it veers of your average app developers. Although I'm not one to turn my back on a challenge, it's hard to get some developers to take a serious & practical look at the realm of possibilities of currently unique tech like this.
There are massive notes & flow charts of practical applications for the Samsung GS2 I've created. To have something like the rotating bezel & touchscreen w/two buttons ON YOUR WRIST is device from heaven. Specially if one makes tethered remote access apps between the GS2 & corresponding cellular phone and/or tablet to control and manipulate other devices the GS2 may not be able to directly connect to. The possibilities are phenomenal.
What do developers think about the time and effort in producing a solid app foundation for Tizen's GS2 market? Even if it means massive collaborations and the drops of egos that us developers have from time to time, the payoff may open doors to greater engineering feats. I love to be on the front lines of progression, paving the way for progressive engineering and inspiring engineers to step out & ACT on their version of visions for tomorrow.
The Tizen SDK is buggy and difficult to get all components installed and playing nicely and Tizen is a little harder to code for than Android. I'm still learning the UI code and overall application structure, but slowly getting there.
I do wish more developers would see the potential market and code for it as I see a whole plethora of possibilities, but very few developers. I'm aiming to get my first app complete and to the Gear store in a month or so. I'll gladly share my experiences here for other potential developers, so they don't make the same mistakes or can learn from my experience.
Oobly said:
The Tizen SDK is buggy and difficult to get all components installed and playing nicely and Tizen is a little harder to code for than Android. I'm still learning the UI code and overall application structure, but slowly getting there.
I do wish more developers would see the potential market and code for it as I see a whole plethora of possibilities, but very few developers. I'm aiming to get my first app complete and to the Gear store in a month or so. I'll gladly share my experiences here for other potential developers, so they don't make the same mistakes or can learn from my experience.
Click to expand...
Click to collapse
I am interested In learning more about it personally, I am bookish but I'm motivated and I'll do everything I can to learn what's necessary
GOIGIG said:
I am interested In learning more about it personally, I am bookish but I'm motivated and I'll do everything I can to learn what's necessary
Click to expand...
Click to collapse
The main thing is to first install the latest Java JDK, not just the JRE, but the full JDK and make sure the environment variables are set correctly. Then install the Tizen SDK and run the update manager. You need to install the certificate and wearable extensions from "Extras", the emulator from "Tizen Tools" and also the relevant tools from the "Wearable 2.3.1" group. Then you can start the IDE (a version of Eclipse) and select a simple example (choose ), try to compile it and run it with the emulator. You need to start the emulator and make sure it's in the "connected devices" area before running the app.
Be aware that the emulator uses a lot of processing power and can run slowly.
There are a number of different types of app you can build for the S2, native or web with different UI components / frameworks.
A good starting point: http://developer.samsung.com/gear
If you want to test your app on your actual S2, this is a great guide: http://www.tizenexperts.com/2015/12/how-to-deploy-to-gear-s2-smartwatch/
If you generate an author certificate, you can use the same one for the GearWatchDesigner, but that app has different Java requirements (32-bit JRE only required).
Focus motion
Oobly said:
The Tizen SDK is buggy and difficult to get all components installed and playing nicely and Tizen is a little harder to code for than Android. I'm still learning the UI code and overall application structure, but slowly getting there.
I do wish more developers would see the potential market and code for it as I see a whole plethora of possibilities, but very few developers. I'm aiming to get my first app complete and to the Gear store in a month or so. I'll gladly share my experiences here for other potential developers, so they don't make the same mistakes or can learn from my experience.
Click to expand...
Click to collapse
hi, there is a free sdk from a company called focus motion , which allows auto recognize the movements made with the smart watch .
Someone would be able to make a test app for samsung gear s2 ?
i don't think so
codenameclass5 said:
I'm new to the Tizen world of development. From what I've been hearing, Tizen is so difficult to program for that it veers of your average app developers. Although I'm not one to turn my back on a challenge, it's hard to get some developers to take a serious & practical look at the realm of possibilities of currently unique tech like this.
There are massive notes & flow charts of practical applications for the Samsung GS2 I've created. To have something like the rotating bezel & touchscreen w/two buttons ON YOUR WRIST is device from heaven. Specially if one makes tethered remote access apps between the GS2 & corresponding cellular phone and/or tablet to control and manipulate other devices the GS2 may not be able to directly connect to. The possibilities are phenomenal.
What do developers think about the time and effort in producing a solid app foundation for Tizen's GS2 market? Even if it means massive collaborations and the drops of egos that us developers have from time to time, the payoff may open doors to greater engineering feats. I love to be on the front lines of progression, paving the way for progressive engineering and inspiring engineers to step out & ACT on their version of visions for tomorrow.
Click to expand...
Click to collapse
i don't think so! tizen very easy to dev
Some help
Hey guys,
I'm actually currently building an Android app to work with the Gear S2 based on the Integrated App model.
But I'm having some issues, as soon as I build my APK and deploy it in debug mode on the mobile phone, the OS immediately says there is no Samsung Gear app and uninstalls the APK.
Does anyone know how to get passed this?

How do I get a striped down version of Android.

Hi everyone,
Here is a little history first. In 2014 I helped develop a traffic counting app for an engineering buddy. I designed the UI's, the flow charts and wrote the 275-page illustrated, developers manual. The developer had it working in less than 6 weeks, thanks to, as he said, "to the awesome documentation provided". The app has been in use since then and has worked flawlessly on the original 24 tablets I originally purchased for him.
Recently, we have been asked to bring the app to a wider audience so, my question is, "Is there a way to prepare an image of the Android OS containing only the setup we need, and then clone it to the new tablets?" The app is designed as engineering tool and is not listed through Google Play and as such, it does not require most of the bloatware found on the new tablets. The app does require the use of photos, some file management along with network connectivity to send and receive the various data files required and produced by the app.
I have limited experience in rooting, but I have been successful when I done it on my Samsung phones.
As a certified Graphics Designer/Windows and Mac tech/COVID-19 survivor (nearly killed me, literally...LOL), I am aware of the amount of work that goes into aiding people with their "little" projects. Any help or direction in this matter would be deeply appreciated.

Categories

Resources