[building OpenSSL for vxWorks on Windows using Cygwin]

[Michael Wojcik]

> From: openssl-users <openssl-users-bounces at openssl.org> On Behalf Of ???? ???
> Sent: Friday, 21 October, 2022 02:39
> Subject: Re: openssl-users Digest, Vol 95, Issue 27

Please note the text in the footer of each openssl-users digest message:

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This is part of asking a good question. Also, you need to trim parts of the digest message you're replying to that aren't relevant to your question. Don't just send the entire digest back to the list. That's confusing and discourteous to your readers.

> - Why are you trying to build OpenSSL?
> My objective is to sign an 'image.bin' with RSA2048 and verify the signature.
> Now, I would like to port it to vxWorks 7. 

See, this is why you need to ask a good question. I believe this is the first time you mention vxWorks, which makes an enormous difference. Prior to this message, I assumed you were building OpenSSL *for Windows*, since that was the only platform you mentioned.

vxWorks is, I believe, an unsupported platform. Someone in the past ported OpenSSL to vxWorks and contributed the necessary changes to the project, but the project maintainers don't have the resources to maintain that port. OpenSSL consumers who want to run on vxWorks have to provide their own support for it.

Had you made it clear you were targeting vxWorks at the start, someone could have pointed that out, and saved us all some trouble.

Since you are targeting vxWorks, you'll need to get advice from someone who's familiar with building OpenSSL for that platform. I am not, and I haven't seen anyone else on the list comment on it yet, so there may not be any vxWorks users reading this thread. And so you may need to look elsewhere -- perhaps on vxWorks forums.

> A: If there an l'ibOpenssl.a'  static library for vxWorks, then there would be no
> reason to build the OpenSSL. Is there? 

I don't know; I don't work with vxWorks.

> A: If there was on option to use Only the verify signature module, then I would just
> compile this module and not the entire OpenSSL. Is there an option?

Not with OpenSSL. There are other cryptography libraries, some of which may be more convenient to get for vxWorks. Verifying an RSA signature in some fashion (you don't say anything about a message format or padding, but that's a whole other area of discussion) is a common primitive.

> > - What platform do you want to build OpenSSL for?
> A: vxWorks-7, the toolchain is windows exe files (gcc,ar,ld), thus the only option
> I had in mind to build the OpenSSL is cygwin.

> > - What toolchain do you want to use, and if that's not the default toolchain for
> > that platform, why aren't you using the default?
> A: I have vxWorks toolchain, on windows platform. (It definitely be easier if I had
> the vxWorks toochain on Linux, but I don't)

This still isn't clear to me. If you have the vxWorks toolchain for Windows, why do you need Cygwin? Is it just for Perl, for the configuration step? I have no idea what the vxWorks tools expect for things like file-path format, so I can't guess whether Cygwin's Perl would be appropriate.

> > - Have you read the text files in the top-level directory of the OpenSSL source
> > distribution?
> Please direct me to the relevant README on "how to build OpenSSL on vxWorks" (or
> similar platform, in which all is needed is to inject the relevant toochain
> i.e. perl Configure VxWorks)

That's not how it works. If you want to build OpenSSL, you should be consulting all of the files to figure out what's relevant for your build. Building OpenSSL is often not trivial, so particularly if you run into problems, the thing to do is actually read those files and understand the build process. Or find someone else who's done it for the the platform you're working with, and ask them.

-- 
Michael Wojcik