Specify version in "Assembly manifest" of private side by side assembly (c++) - c++

I am creating a private side by side assembly and need to generate an Assembly manifest for that dll. The problem is that I don't know how I can specify a version to this manifest. (The version of dll/build is #defined in a header file)
I need to generate a manifest file like the one shown below. Present I uses a static manifest file with below content and specify it in project settings->Manifest Tool->Input and output->Additional Manifest Files. The only problem with this approach is that, I can't change the version.
<?xml version="1.0" encoding="UTF-8" standalone="yes"?>
<assembly xmlns="urn:schemas-microsoft-com:asm.v1" manifestVersion="1.0">
<assemblyIdentity type="win32" name="MyCompany.MyDll" version="1.0.0.0"
processorArchitecture="x86" ></assemblyIdentity>
</assembly>
Please advice, what is the correct procedure to create assembly file for private side by side dll.

Related

Assembly identity names in SxS manifests

I have two questions regarding activation context API and SxS manifests. They look like very simple, but still I cannot find any good answer for them.
I have two dll libraries with filenames foo.dll and bar.dll, both with embedded manifests, foo depends on bar. Is there any way to assign these two with assemblyIdentity name other than their filename? For example if I want assembly identity of bar.dll to be CompanyName.Subsection.bar ? If I change it's identity like this - I get error while I try to load foo.dll "Dependent Assembly CompanyName.Subsection.bar,type="win32",version="0.1.2.3" could not be found". Of course if I specify name assembly identities as filenames (<assemblyIdentity name="bar") everything works, but is there a way to use these dotted names?
foo.dll
<?xml version="1.0" encoding="UTF-8" standalone="yes"?>
<assembly xmlns="urn:schemas-microsoft-com:asm.v1" manifestVersion="1.0">
<assemblyIdentity name="foo" version="0.1.2.3" type="win32"/>
<dependency>
<dependentAssembly>
<assemblyIdentity name="CompanyName.Subsection.bar" version="0.1.2.3" type="win32" />
</dependentAssembly>
</dependency>
<file name="foo.dll">
</file>
</assembly>
bar.dll
<?xml version="1.0" encoding="UTF-8" standalone="yes"?>
<assembly xmlns="urn:schemas-microsoft-com:asm.v1" manifestVersion="1.0">
<assemblyIdentity name="CompanyName.Subsection.bar" version="0.1.2.3" type="win32"/>
<file name="bar.dll">
</file>
</assembly>
It can be done if instead of embedding the manifest for bar.dll you place it in a separate folder together with the dll itself. I.e.:
foo.dll
CompanyName.Subsection.bar/
├── bar.dll
└── CompanyName.Subsection.bar.manifest
You still need to embed the first manifest into foo.dll. I'm confident that you can remove the following snippet from that manifest, because it's an embedded manifest and therefore needs not to specify what dlls belong to the assembly:
<file name="foo.dll">
</file>
The manifest for bar.dll is good, but be sure to name the folder and the manifest file exactly as specified in the assemblyIdentity element (see example folder structure above).
Also note, that you can diagnose problems related to loading SxS assemblies with the sxstrace command line tool. Step by step instructions:
Run sxstrace trace -logfile:mytrace.etl from a Visual Studio Command Line. The command will not return until you press ENTER. However, do not press ENTER yet.
Start the application that loads foo.dll to reproduce your issue
Then press ENTER in the Command Line window to stop sxstrace
You now have a file mytrace.etl, which is not human readable. Convert it to a readable format by running sxstrace parse -logfile:mytrace.etl -outfile:mytrace.txt. You get a file mytrace.txt which shows what happens, when you load foo.dll and where it fails to resolve some of its dependencies.

LoadLibraryEx ignores side-by-side manifest

Does LoadLibraryEx function use side-by-side manifests? I have bar.dll with embedded SxS manifest, and that manifest describes version of this bar.dll, other dll file foo.dll has manifest that lists bar.dll as dependency, with specified version. But when I try to load bar.dll from foo.dll with LoadLibraryEx("bar.dll", NULL, 0) I see (with enabled sls with gflags) that it ignores these manifests, and loads first version of bar.dll that it sees in searchpath, if I define ISOLATION_AWARE_ENABLED and use LoadLibrary it finds right version, but this ISOLATION_AWARE_ENABLED doesn't affect behaviour of LoadLibraryEx, I need to load right version with LoadLibraryEx because LoadLibraryEx is used implicitly for delayed loading of dll's. Is LoadLibraryEx supposed to work like this, or is it some problem in my project configuration?
foo dll
<?xml version="1.0" encoding="UTF-8" standalone="yes"?>
<assembly xmlns="urn:schemas-microsoft-com:asm.v1" manifestVersion="1.0">
<assemblyIdentity name="foo" version="0.1.2.3" type="win32"/>
<dependency>
<dependentAssembly>
<assemblyIdentity name="bar" version="0.1.2.3" type="win32" />
</dependentAssembly>
</dependency>
<file name="foo.dll">
</file>
</assembly>
bar.dll
<?xml version="1.0" encoding="UTF-8" standalone="yes"?>
<assembly xmlns="urn:schemas-microsoft-com:asm.v1" manifestVersion="1.0">
<assemblyIdentity name="bar" version="0.1.2.3" type="win32"/>
<file name="bar.dll">
</file>
</assembly>
LoadLibrary used active activation context of the calling thread. but which is this context ? why it must be from your foo.dll ? why not from xyz.dll or from exe ? really most time active activation context was exactly from exe.
if dll have own manifest - system create activation context for this dll and save it (until dll will be unloaded) but not make it active. and this is obviously - we have multiple dlls in process, but active context only one - from which dll select it ? from exe. however system activate (make it current active) dll activation context before call it entry point. and deactivate it after entry point return. but say inside another dll functions - (who called it ?) the context already not from your dll.
so solution must be next:
define 2 global variables in dll:
BOOL gActCtx;
HANDLE ghActCtx
on DLL_PROCESS_ATTACH save current activation context (it from your dll manifest)
gActCtx = GetCurrentActCtx(&ghActCtx);
free it on DLL_PROCESS_DETACH
if (gActCtx) ReleaseActCtx(ghActCtx);
and when you need load bar.dll do next:
if (gActCtx)
{
ULONG_PTR Cookie;
if (ActivateActCtx(ghActCtx, &Cookie))
{
LoadLibraryExW(L"bar.dll", NULL, 0);
DeactivateActCtx(0, Cookie);
}
}

How does Windows 7 determine, if you need admin rights? (vc60)

Problem: I'm writing unittests for a Setup program in c++. The Setup needs admin rights, but the unittests do not. On starting the tests, I get asked for starting the test/program as Administrator.
This started happening when I included the rc-file of the original project.
Edit: I was upgrading this project to VS2010, but still using vc60, so there is no manifest support. This might be related.
Generally, the resources contain a manifest, and a portion of the manifest states whether the program needs administrator access. Since this is a setup utility, it probably has a manifest requiring administrator access and your tests picked it up when it tried to share the resource file.
(Other people are talking about the heuristics used to guess whether a program needs administrator access when it doesn't have a manifest. For example, if you have an old program that was made before manifest files were common, the OS might try to guess whether it's an installer by looking for certain phrases like "setup" in the file name. I believe there are other heuristics as well. This is a hack for older programs that were written before manifests made it possible to explicitly declare your need for administrator access.)
You can fix your problem by providing your own manifest. The easiest way is to use the /MANIFESTUAC linker option.
If you're using an older toolchain, you'll probably have to make the manifest file yourself and include it in your resources.
The manifest is a chunk of XML. The important bit for you would look something like this:
<?xml version="1.0" encoding="UTF-8" standalone="yes"?>
<assembly xmlns="urn:schemas-microsoft-com:asm.v1" manifestVersion="1.0">
<assemblyIdentity version="1.0.0.0" name="yourprogram.exe" type="win32"/>
<trustInfo xmlns="urn:schemas-microsoft-com:asm.v3">
<security>
<requestedPrivileges>
<requestedExecutionLevel level="asInvoker"/>
</requestedPrivileges>
</security>
</trustInfo>
</assembly>
To embed this in your resources, your .RC file should have:
1 RT_MANIFEST <filename>
If your SDK is so old that RT_MANIFEST is not defined, you can define it yourself:
#define RT_MANIFEST 24
One criteria for evaluating the needed rights for an application is the name.
So if the name contains the Word "Setup", you will be asked for admin rights.
Also, as this started with the rc file, another criteria are the names written in the rc-File, under "Version". In my case in "VS_VERSION_INFO".
The following entries are should not contain the word Setup:
FileDescription
InternalName
OriginalFilename
ProductName
You might change any occurance of "Setup" to "Settup". That would prevent the dialog.
Even though, you might not be able to change this in the "real" rc-file.

Why cant I drop a file into the Qt Sample drop example?

I am trying to get dropping a file into the application to work and so I compiled the example but every time I try to drop a file, I get the "not allowed to drop" symbol. I tried this also with my own example and in debug mode I find that none of the implemented functions (dragEnterEvent, dragMoveEvent, dropEvent) are even reached. What is the problem here / how do I fix this?
Also, running Qt 4.8 on Win7 x64
I found the issue: you cant drag and drop from a non escalated application (explorer.exe) to an escalated one.
Thanks to #HansPassant for the workaround: add a manifest file:
<?xml version="1.0" encoding="UTF-8" standalone="yes"?>
<assembly xmlns="urn:schemas-microsoft-com:asm.v1" manifestVersion="1.0">
<trustInfo xmlns="urn:schemas-microsoft-com:asm.v3">
<security>
<requestedPrivileges>
<requestedExecutionLevel level="asInvoker" uiAccess="true"/>
</requestedPrivileges>
</security>
</trustInfo>
</assembly>
This manifest requires 'uiAccess' to be true and that requires the exe to be trusted and signed.
Note: the solution proposed in http://helgeklein.com/blog/2010/03/how-to-enable-drag-and-drop-for-an-elevated-mfc-application-on-vistawindows-7/ using ChangeWindowMessageFilter does NOT work.

Load 2 versions of the same DLL in the same process

I want to do exactly what it is described here, but the accepted solution does not work for me. I suppose the reason is explained here :
If a DLL with dependencies is loaded
by specifying a full path, the system
searches for the DLL's dependent DLLs
as if they were loaded with just their
module names.
If a DLL with the same module name is
already loaded in memory, the system
checks only for redirection and a
manifest before resolving to the
loaded DLL, no matter which directory
it is in. The system does not search
for the DLL.
I wish to have my application in the following structure.
c:\Exe
|
|----- c:\DLL\DLL.dll, c:\DLL\common.dll
|
|----- c:\DLL2\DLL2.dll, c:\DLL2\common.dll
My EXE will load the DLLs through
LoadLibrary("c:\\DLL\\DLL.dll");
LoadLibraryEx("c:\\DLL2\\DLL2.dll");
common is implicitly loaded in both cases.
I tried the SetDllDirectory option, but there is always only one common.dll loaded.
I added version information in common.dll. c:\DLL\common.dll has version 2.0.1.0 while c:\DLL2\DLL2.dll has version 4.0.1.0
I embedded the following manifest with the corresponding version info, but it did not help.
<?xml version="1.0" encoding="UTF-8" standalone="yes"?>
<assembly xmlns="urn:schemas-microsoft-com:asm.v1" manifestVersion="1.0">
<dependency>
<dependentAssembly>
<assemblyIdentity type="win32" name="common" version="4.0.1.0" processorArchitecture="x86"></assemblyIdentity>
</dependentAssembly>
</dependency>
</assembly>
Is there a solution to this problem ?
Where have you embedded the manifest? The EXE or the DLLs?
You have two basic ways of doing this, both involve turning "common" into a private SxS assembly by creating a manifest for it.
Then:
If DLL and DLL2 contain manifests listing dependent assemblies, then you need to add a dependentAssembly to their manifests specifying "acme.common" (for example) as a dependent assembly. As dependent assemblies are always searched for, by default, in the loading modules folder, each DLL will load its own local copy of common.
If you are just relying on the applications default activation context to do most of the heavy lifting, then you can try using the ActivationContext API.
Call CreateActCtx twice, specifying two the two different folders as the base folder for the resulting context.
In pseudo code:
HACTCTX h1 = CreateActCtx( ... for DLL ... );
HACTCTX h2 = CreateActCtx( ... for DLL2 ...);
ActivateActCtx(h1,...);
LoadLibrary("C:\\DLL\\DLL1.DLL");
DeactivateActCtx();
ActivateActCtx(h2,...);
LoadLibrary("C:\\DLL2\\DLL2.DLL");
DeactivateActCtx...
If the dlls already contain their own manifests the system will use those. If not, this will let you specify a search directory for private assemblies without modifying the dll's themselves.
To implement Option 1:
First, I don't recommend trying to use the dll name as the assembly name. So, create a manifest that looks like this in each folder:
<!-- acme.common.manifest -->
<assembly manifestVersion="1.0">
<assemblyIdentity type="Win32" name="acme.common" version="1.0.0.0" processorArchitecture="x86"/>
<file name="common.dll"/>
</assembly>
You can fix the version number to match common.dll's version in each folder, but thats not important.
Then, either the manifest you list, or a directive like this if you are using Visual Studio
#pragma comment(linker, "/manifestdependency:\"acme.common'"\
" processorArchitecture='*' version='1.0.0.0' type='win32'\"")
Just make sure the dependent assembly versions match the versions of the corresponding 'acme.common' assembly.