Add support for .net core target .exes

[mungojam]

• Fixes #1644, adding direct support for .net core exes by looking for the assembly custom attribute in the actual .net backing DLL rather than in the native .exe entry point that .net core builds create.

• I've added a .dll and some .exes as test fixtures, but I can understand if you want to reproduce these yourself for security reasons.

[dakahler]

Would love to see this pulled in!

[samirem]

@mungojam Any chance you could publish this as a NuGet-package? I would like to use it in my cake build.

[mungojam]

@anaisbetts this one seems to be popular, do you think you will have a chance to look at this?

[ComtelJeremy]

@anaisbetts This issue is keeping us from moving our Squirrel distributed app to .NET Core (or 6 when it is available). CreateDump.exe is now included (and required without some json editing) in published builds, so even if our app is one exe Squirrel sees both and adds a shortcut for "Microsoft .NET" to the desktop. A fix is needed to mark our app as "SquirrelAware". This PR seems to address this.

If there is a better workaround (i.e. some other way of telling Squirrel to only create shortcuts for one 'non C#' app - which seems to be the recommended way to use Squirrel with .NET Core apps) we would be very grateful for the guidance.

[anaisbetts]

Part 1 is an easy win, I'd take that PR. Part 2 I still do not understand why .NET Core does this, and I'm a little squicked out opening up random DLLs and hoping they're related

[mungojam]

Part 1 is an easy win, I'd take that PR.

I could split the PR if that would help, but note that with just Part 1, people would need to add a post-build step to actually make use of it by calling rcedit to add the SquirrelAware attribute.

Part 2 I still do not understand why .NET Core does this, and I'm a little squicked out opening up random DLLs and hoping they're related

@anaisbetts, with .net core 1 and 2, I think it originally forced you to run the DLLs and didn't even have an exe. With .net core 3.0 (I think), they added the launcher .exe that then loads the DLL. So the DLL is really where your code lives and will always be named the same as the exe. Would it help if it somehow detected for sure that the .exe is a .net core wrapper exe? I don't know how easy that is though or if it would be fragile to different .net core versions.

[anaisbetts]

Would it help if it somehow detected for sure that the .exe is a .net core wrapper exe?

Yeah, I think that would be a bit safer

[mungojam]

Would it help if it somehow detected for sure that the .exe is a .net core wrapper exe?

Yeah, I think that would be a bit safer

@ComtelJeremy, with your offer of help. If there is any research you are able to do into this aspect that would be helpful. I will try and get to looking at it in the next few days, but no guarantees

[ComtelJeremy]

@mungojam Taking a quick look, I noticed that in our project in the properties for the .exe there is a property called "Original filename". It has the .dll name and extension in it... Would this be enough to make us look if there is a matching .dll with that name in the package? This might not be bulletproof, or futureproof, but might be a good sanity check before checking the .dll for attributes.

See below:

[mungojam]

@mungojam Taking a quick look, I noticed that in our project in the properties for the .exe there is a property called "Original filename". It has the .dll name and extension in it... Would this be enough to make us look if there is a matching .dll with that name in the package? This might not be bulletproof, or futureproof, but might be a good sanity check before checking the .dll for attributes.

Nice, thanks! That would work for me, how about you @anaisbetts? I can try and implement that in the next few days.

[anaisbetts]

I would actually try to analyze the executable itself to try to find some sign that it is a renamed dotnet.exe. I'll look into it soon

[mungojam]

I would actually try to analyze the executable itself to try to find some sign that it is a renamed dotnet.exe. I'll look into it soon

A few things to help with the decision:

1. This SO answer seems to cover it best. I'm not sure what you mean by 'renamed' dotnet.exe. It's quite like the very cool squirrel stub exe but subtly different for each app I guess, for example it will be different for console apps vs. WPF apps.

2. I've put together a version of my change that uses the OriginalFilename attribute instead of just assuming that the filename extension just needs changing:

https://github.com/mungojam/Squirrel.Windows/commit/db6188044f921ba60832175f2f42a5d8ccc1fec5

3. I've pulled out all of the FileVersionInfo properties from the launcher .exe, none of which make it clear that it is a .net core launcher .exe. But you may be able to find other information in the file to identify it.

    Comments: ""
    CompanyName: "SquirrelAwareNetCoreApp"
    FileBuildPart: 0
    FileDescription: "SquirrelAwareNetCoreApp"
    FileMajorPart: 1
    FileMinorPart: 0
    FileName: "the-full-path-to-the-exe-on-my-machine\\Squirrel.Windows\\test\\fixtures\\SquirrelAwareNetCoreApp.exe"
    FilePrivatePart: 0
    FileVersion: "1.0.0.0"
    InternalName: "SquirrelAwareNetCoreApp.dll"
    IsDebug: false
    IsPatched: false
    IsPreRelease: false
    IsPrivateBuild: false
    IsSpecialBuild: false
    Language: "Language Neutral"
    LegalCopyright: " "
    LegalTrademarks: ""
    OriginalFilename: "SquirrelAwareNetCoreApp.dll"
    PrivateBuild: ""
    ProductBuildPart: 0
    ProductMajorPart: 1
    ProductMinorPart: 0
    ProductName: "SquirrelAwareNetCoreApp"
    ProductPrivatePart: 0
    ProductVersion: "1.0.0"
    SpecialBuild: ""

[ComtelJeremy]

@mungojam Were you going to split the PR? With Part 1 at least we would be able to move forward with marking one of the exes in our app as SquirrelAware. We don't mind a post-build step...I already do one to releasify. I would simply add that step to the script I have already.

@anaisbetts Anything we can do to help with a possible Part 2?

[mungojam]

@mungojam Were you going to split the PR? With Part 1 at least we would be able to move forward with marking one of the exes in our app as SquirrelAware. We don't mind a post-build step...I already do one to releasify. I would simply add that step to the script I have already.

Sure, I'll try and put that in this afternoon. It's good to know it would be used

[AArnott]

@mungojam This PR doesn't solve the CreateDump.exe problem as far as I can see. What was your plan to solve that part?

[AArnott]

Never mind. I see that this PR works when combined with an app that includes: [assembly: AssemblyMetadata("SquirrelAwareVersion", "1")]

[AArnott]

I don't see much traction on this repo. To get unblocked I built this PR locally and pushed the package to my own public feed so I can consume it. I share here in case anyone else wants to consume it as well.

[mungojam]

Note that .net 6 resolves the specific createdump problem to a degree as it no longer lists it as a dependency so it can be deleted as a post build, pre squirrelise step.

[ComtelJeremy]

@anaisbetts Just wondering if this might be merged and released and/or #1732 might be released in the near future... We are in the middle of upgrading our .net framework squirrel installed app to core, and it contains two exes (one called by the first exe for elevated tasks). Having a working SquirrelAwareVersion assembly attribute will prevent us having to do some exe renaming before and after install. Also happy for any other workaround you or others can suggest. We love squirrel and want to keep using it!

That being said, if any help is needed, please point me in the right direction and I'll do my very best.

[mungojam]

@anaisbetts I've just spotted the comments on https://github.com/Squirrel/Squirrel.Windows/pull/1752#issuecomment-933437822 about this one.

I wonder if I can help resolve the concern around it. It only goes looking for the partner dll if it doesn't see the squirrel aware flag on the .exe. And it will only then report the DLL if the DLL has the squirrel aware flag. I don't see what the risk of doing that would be with other languages. If for some reason they have flagged the DLL then it wouldn't serve any purpose at present.

[caesay]

@mungojam FYI my fork has removed the dependency on mono.cecil and now has several other ways of detecting a binary as squirrel aware that are friendly to net framework, dotnet core, publishsinglefile, and are even consistent with how it's done for native binaries, so this change is not needed. The preferred way to mark a binary as SquirrelAware is now an added line in the assembly manifest - which is easy to do for dotnet and native binaries alike. There are also many other fixes in this repo and it is being actively maintained.

[mungojam]

Closing this to reduce my open PR noise and as it doesn't look likely to get merged ever. The fork mentioned by @caesay has now become https://github.com/velopack/velopack which is worth a look