Some questions about Windows' DLLs? - dll

I wrote an application in a JS-based framework called Titanium. This framework doesn't have some functions, so I'm bundling autohotkeys, and using STDIN/STDOUT to connect the two. Autohotkeys has a cool function DllCall which allows to interconect with the operating system and should help me close the gap between the JS-based framework and the missing functionality.
To give you an example, Titanium allows me to bind to a specific port. But if I bind to 0 and let the OS pick a free port (as it should), it will work, but there's no way to tell which port it actually bound to.
Now since I come from web applications, DLLs are new to me; so I have a few questions:
Is there like a big doc with all the DLLs and all their methods?
How do I know if some methods are dependent on some services? I mean I've heard some rely on RPCs, COM, COM+, WMIs, etc. which a user can turn off and if it does, these methods won't work. Is there also a place where I can get more info on this?
Are there any off-the-shelf DLLs, with their methods, which I can trust that they will work 100% from XP up to 7?
Are there any access permissions I should know about? Are they documented.
If you also come from web programming, is there anything else I should be aware about?
Thank you very much.

You can find a (mostly) complete documentation of all Windows API functions (which reside in DLLs) either online on MSDN or offline using the documentation from the Windows SDK.
For example look at the documentation for SHGetSpecialFolderPath. There you can find various information, like the DLL (shell32.dll), any prerequisites (min. IE 4) and the platform availablity. (min. Windows 2000) Also security considerations are documented.
All API functions are documented more or less in this manner. A good starting point is the Windows Developer Reference. From there you can browse through the many API functions.

Basically the answer to every question is that you should search MSDN for the functions or APIs you are interested in and read the documentation there:
http://msdn.microsoft.com/en-us/library/ms123401.aspx
They document which operating systems the functions are available in so it should be easy to write something that works in Windows XP and up.

Related

How are WinRT / Metro apps restrictions enforced?

The new Metro style / WinRT apps in Windows 8 have certain restrictions as to which APIs you can call. Also, you have to use asyncronous techniques and your app has to be pauseable, etc.. I'm wondering how, and if all of this is enforced.
Are the new Metro apps simply execuable programs, or are they something else (e.g. more like COM controls, with a set of defined interfaces)? How are the API restrictions enforced, at compilation, at runtime (via sandboxing etc.) or just via Windows Store policy (similar to the situation in iOS)? If I was feeling devious, could I e.g. get a handle to the screen and manipulate the interface, add floating windows on top, launch something in the background, or otherwise break out of the confines of Metro?
One reason I'm asking is that I'm looking into creating a WinRT library for Python, so that one could use it for writing Metro apps. However, the Python core obviously uses a lot of non-WinRT API calls, so this might be doomed from the beginning. I'd also like to get a feel for the anatomy of Metro apps in general.
Edit: According to this thread, you have all the functions of the C runtime available. It seems like you can compile stuff that calls forbidden functions, but the "application verifier" complains. I'm wondering if you could just run such a hybrid app, if you don't care about the Store (and maybe make it Store compatible later by writing workarounds for the forbidden functions)...
There are (at least) two separate sets of technical restrictions on what a Metro style Windows Store app can do.
The first is a set of security restrictions: Windows Store apps run with low privileges, and thus are limited in how they are permitted to interact with the rest of the system. For example, a Windows Store app cannot access arbitrary locations in the filesystem, it can only access files in a predefined set of locations, and files to which the system expressly gives access. You cannot violate these security restrictions (if you could, that would be a rather problematic operating system bug).
The second set of restrictions is the API partitioning. Windows Store apps are only permitted to call system functions that are present in the App Partition. The documentation for each system function on MSDN specifies whether the function is present in the App Partition. You can also find out by looking in the header file that defines the function: functions are conditionally defined depending on the API partition targeted by the project: the WINAPI_FAMILY macro controls this (see winapifamily.h in the Windows SDK for more information).
If you call an "unapproved" function, the results are undefined. It might appear to work; it might fail catastrophically. It might appear to work fine today and fail catastrophically tomorrow (or after a Windows update is applied, or with the next version of Windows).
The API partitioning is enforced in various ways. The headers are constructed such that it is difficult to call an unapproved function. If you define the function yourself or change the WINAPI_FAMILY, your app will fail the Windows App Certification Kit (WACK) process. My understanding is that the CLR prohibits calls to unapproved .NET functionality at runtime, though I am less familiar with the .NET restrictions. In any case, my understanding is that if your app calls an unapproved function, you cannot submit it to the store, per the "Windows 8 app certification requirements" (please read those requirements yourself, though; I have not read them in detail and I certainly can't interpret them for you).
If you don't care about submitting your application to the Windows Store or just want to write some test apps or play with WinRT, then there's nothing stopping you from trying to call unapproved functions. For example, I find it is useful to create a console window for debugging purposes. That appears to work fine, and I don't much care that it fails Windows Store certification since it's for debugging and testing only.
They aren't standard executables. You're restricted to a subset of .Net 4.5 to create the applications which doesn't let you (or rather, makes it extremely difficult to) do anything that MS don't want Metro apps doing. They're pretty heavily sandboxed as well.
You have a limited part of the .net api available:
The .NET Framework provides a subset of managed types that you can use
to create Metro style apps for Windows using C# or Visual Basic. This
subset of managed types is called the .NET for Windows Store apps and
enables .NET Framework developers to create Metro style apps within a
familiar programming framework. Any types that are not related to
developing Metro style apps are not included in the subset.
You use
these managed types with types from the Windows Runtime API to create
Metro style apps. Typically, you won't notice any differences between
using the managed types and the Windows Runtime types except that the
managed types reside in namespaces that start with System, and the
Windows Runtime types reside in namespaces that start with Windows.
Together, the .NET for Windows Store apps and the Windows Runtime
provide the complete set of types and members available for developing
Metro style apps with C# or Visual Basic.
There are app store requirements.
3.1 You must use only the Metro style APIs to implement the features of your Metro style app We describe these APIs in the Metro style apps
API reference. Your app may only depend on software listed in the
Windows Store.
Apps are sandboxed.
In short, you must you the api provided.

Can WinRT application use obfuscation?

All Metro applications must be inspected before distribution through Windows 8 AppStore. Does this mean it will not be allowed to use code obfuscation? Or it is still possible, and only some specific aspects are going to be monitored during such inspection?
Here are some facts:
Marketplace for WP7 allows C# apps be obfuscated (even MS he advises
doing so) and I don't see any reason why Windows AppStore would ban
such apps.
It is almost certain that some vendors will provide compatible C++
obfuscator.
You should care about your clients not crackers. :)
a lot of hacks for code obfuscation will be banned.
Remember, if you have some logic that you want to hide, make a webservice and consume it in your client app. Better spend your time building better app, fixing bugs etc.
No dice, if someone has access to the binaries is just a matter of time when someone cracks it.
This is an armchair answer with some things that come to mind:
Even a C++ application can still be anazlyed if it depends on dynamic linking to a runtime or API, which is the case with WinRT applications. Microsoft approval can in theory include automated or human guided testing of your app using a special sandbox and/or OS hooks capable of detecting if your application attempts certain prohibited operations.
Under the hood, C++ apps for WinRT are more like native C++ apps than C++/CLI, so obfuscation is not needed to the degree that it is for C#, all things being equal.
You can still build C# apps that target WinRT, but your code will still be compiled to CIL and run within the CLR (more or less), invoking WinRT through wrappers that Microsoft provides. Because it's CIL, the question of obfuscation should be equivalent to that of C#/.NET obfuscation in general.
Obfuscation is still possible for WinRT. The inspection made by the Application Certification Kit cover lot of aspects including metadata and IL verification. Just like the old peverify did.

Convert Smart Device Dll to ActiveX control for Windows Mobile

I am using C# and Visual Studio 2008.
I have a class that will turn on the scanner of my Windows Mobile Device and then will capture the read of the scanner when pressed. It will also shut down appropriately and cleanly. I am using a vendor provided SDK to do a lot of the heavy lifting.
I have this working correctly in a Mobile App, but I also need the dll to be able to be called via COM/ActiveX from a web site. I have been going around and around about how to do this. I've bounced between various settings and project types. I've tried converting it over to C++ and ATL. But so far nothing works.
I get conflicting information depending upon where I look. I need help. Can only C++ do this? Is there something I'm missing? I can't be the only person needing to do this. How can I do this?
You cannot create ActiveX/COM components in managed code with the Compact Framework. There is not EE Hosting support, so it simply cannot be done. You will have to write this in C++ (not managed C++, but old-fashioned native).
As a side note that is sometimes overlooked on COM controls, you also have to implement IObjectSafety for the control to work in a browser.

VB6 Parser/Lexer/Scripter

I've got a game in VB6 and it works great and all, but I have been toying with the idea of creating a scripting engine. Ii'm thinking I'd like VB6 to read in flat text script files for me and then lex/parse/execute them.
I have good programming experience, and I've built a simple C compiler, as well as a LOGO emulator before.
My question is:
Are there any tools that I can use, like Lexx/Yakk/Bison to help me? How should I approach this problem in regards to lexing, parsing, and feeding the commands back to VB6 so I can handle them? Is this idea a BAD IDEA in the sense that there are too many obstacles in the way (For example, building minesweeper in assembly, though not impossible, is very difficult, and a bad idea.)?
Use the Microsoft® Windows® Script Control because it is easy to integrate into existing VB6 applications. The control supports VBScript, JScript, or any other "Active Script" implementation.
I have used the Windows Script Control in four projects and it works extremely well. Very easy to integrate. I wish Microsoft would have given us a replacement in .NET, and made it as easy to use. (I understand the control is not needed in .NET, but having the ability to simply create an object that handles everything is nice.)
Windows Script Control
The Microsoft® Windows® Script Control
is an ActiveX® control that provides
developers with an easy way to make
their applications scriptable. This,
in turn, enables users to extend
application functionality through
scripts, much as they do with macros
today.
INFO: Where to Obtain the Script Control at http://support.microsoft.com/kb/184739. Includes links to other howto support articles.
Chapter 13: Adding Scripting Support to Your Application at http://msdn.microsoft.com/en-us/library/aa227413(VS.60).aspx
Designing a Calculator at http://msdn.microsoft.com/en-us/library/aa227421(VS.60).aspx
How To Use Script Control Modules and Procedures Collections, Inserted from http://support.microsoft.com/kb/184745
How To Use the AddObject Method of the Script Control, Inserted from http://support.microsoft.com/kb/185697
SAMPLE: SCRIPTEX.EXE Uses the ScriptControl with Visual Basic, Inserted from http://support.microsoft.com/kb/189484
Windows Script Control can be downloaded at http://www.microsoft.com/downloads/details.aspx?familyid=d7e31492-2595-49e6-8c02-1426fec693ac&displaylang=en. (Supported Operating Systems: Windows 2000; Windows 98 Second Edition; Windows ME; Windows NT; Windows Server 2003; Windows XP)
MSDN Search of "MSScriptControl.ScriptControlClass" at http://social.msdn.microsoft.com/Search/en-US?query=%22MSScriptControl.ScriptControlClass%22&ac=8
MSDN Search of "Windows Script Control" at http://social.msdn.microsoft.com/Search/en-US?query=%22Windows+Script+Control%22&ac=8
MSDN Search of "MSSCRIPT" at http://social.msdn.microsoft.com/Search/en-US?query=MSSCRIPT&ac=8
Unless you're doing it for your own instruction, you may want to try using Lua: VB6 - Lua Integration
If you're willing to use VBScript rather than VB6 you might be able to just use the MSScriptControl to run the commands rather than creating your own. Here's an article discussing using it from a .Net app, though it's an ActiveX control so should give you quite a bit of flexibility.
The control can be downloaded from here.
I've actually seen some quite reasonable implementations of compilers/interpreters in VB6[1] - It's not the language I would choose (few functional features, insufficent static type system), but with experience, you can outweigh these drawbacks and be quite productive - So why not.
You can use the GOLD parser generator that supports VB6 as a start.
[1]: Somewhere on PSC or in this download repository I think ...
Note that there is the MSScriptControl too.
There also appears to be an additonal alternative for VB6:
SadScript is an variant of VB6 most prominently used for VB6 as an scripting engine in MMORPGS .
See here for more : What is sadscript? Can I use it in vb.net? Why hasn't anyone I have asked heard of it?

Ideal UI markup language

A friend of mine and I are looking to start a project looking into accessible user interface (for blind users) design. There are a number of projects making existing GUI's accessible by tagging them with audio information but we're looking to work from the ground up and actually take input from a ML and create an accessible application.
I'm trying to figure out what ML to use and am torn between three at the moment. The three I'm considering are XAML,MXML, and XUL. Currently, I'm leaning towards XUL because it's open but I was wondering if anyone could think of any pros/cons that I might be missing? I know that XAML is the most popular but does it do things that XUL can't? How similar are they?
I should add that whatever ML we end up using we will be extending the syntax so that we can provide additional information to the audio system.
I have already addressed this question to some extent here.
The pros/cons of XUL are:
it's open
it's cross platform
it's well established with a large community
it still basically has to be run in a browser that supports XUL (firefox)
one of the comments from my question stated that XUL is a bad choice because firefos is buggy
The pros/cons of XAML are:
it'll work on Windows/Mac
it has a well established drag-drop IDE (VS 2010) to create GUIs
it has a massive support community
it's closed source
it's a closed platform, IE. it not an open standard (not covered under ECMA like .NET and C#)
there are legal issues regarding the use on non microsoft/mac plagforms (see my post)
it requires either a browser with a the silverlight plug-in or the .NET framework to use it on the desktop
it's developed/controlled by MS. This isn't an attempt to troll. Seriously, look it up on google. There are a lot of people who are suspicious of MS's intent behind creating XAML and it has garnered a lot of negativity behind the platform. It might be worth taking into consideration.
The pros/cons of MXML:
it's cross platform
it's closed source
it runs on a closed platform
it requires adobe flash (which, a lot of people claim is a dying platform now that Apple is rejecting to support/allow it).
it requires a browser with a plug-in
Note: I can't really say much about MXML because this is the first time I've heard about it. I just pointed out the obvious pros/cons for completeness. I'll have to research it and add an entry to in the question I linked.
XUL application can be run under XUL Runner because after Firefox 4, remote XUL application execution within Firefox browser is prohibited