Windows Arm64 - building from source

[doberst]

Hi Cryptography team!

I am trying to use the library on a Windows ARM64 machine, and looks like the only alternative is to build from source. I have set up the environment with the OpenSSL binaries for ARM64, but am having a lot of difficulties compiling the Rust source code, and the recipes provided in the documentation do not seem to be up-to-date or provide enough detail to get it working.

After a lot of tinkering, the Rust "cargo build" will find the OpenSSL binary, but then later in the process throws an error around not being able to find the path to "build_openssl.py" (from src\rust\cryptography-cffi\build.rs @ line 36). I have tried multiple obvious ways to ensure it finds the path, and not finding success with any. (Please note: I am not a Rust programmer - and am trying to use the cryptography library in a Python/C/C++ project.)

Welcome any feedback or advice. Generally, it would be great if you could support Windows ARM64, or alternatively, provide a more detailed recipe for how to build from source for this use case.

Thanks!

[alex]

We'll ship Windows ARM64 wheels as soon as Github offers ARM64 Windows runners (#11199).

Have you tried using vcpkg to install OpenSSL?

[reaperhulk]

vcpkg may make this simple, but if you have an installation of OpenSSL at a path like C:\openssl (with lib and include dirs under that) you can add OPENSSL_DIR=C:\openssl to your environment vars and the rust compilation will see it when invoked by the Python build machinery.

[doberst]

@reaperhulk and @alex - thanks for your suggestions - I have not used vcpkg, but have installed OpenSSL and set the path as you describe but still getting errors in the Rust compiling process. I will explore vcpkg and other config options. Will close the loop when I get it resolved. Welcome and appreciate any other ideas. :)

[github-actions]

This issue has been waiting for a reporter response for 3 days. It will be auto-closed if no activity occurs in the next 5 days.

[dlech]

I had success with:

winget install ShiningLight.OpenSSL.Dev
$env:OPENSSL_DIR="C:\Program Files\OpenSSL-Win64-ARM"
$env:OPENSSL_LIB_DIR="C:\Program Files\OpenSSL-Win64-ARM\lib\VC\arm64\MT"
$env:OPENSSL_STATIC="1"

[doberst]

@dlech - thanks for this suggestion - I am going to try your approach this morning

[doberst]

@dlech - thanks, your suggestion is spot-on for getting OpenSSL installed on Win64-ARM. Perhaps I am missing something obvious (so apologies in advance) - but how are you building/compiling cryptography from source after these instructions. I have tried several paths, and getting errors in all of them. If you could complete the recipe with the next couple of lines to get cryptography built (e.g., rust pyd), I would really appreciate it! :)

[dlech]

I just did poetry install on a project that has cryptography as a dependency. So basically, it should be the same as pip install cryptography.

For a different dependency (not sure if it is related to cryptography or not), I had to set $env:PYO3_USE_ABI3_FORWARD_COMPATIBILITY="1" to get it to build on Python 3.13. That might have been the rust-pyd that you are referring to, but I don't have the terminal output anymore to check.

[doberst]

Thanks to @dlech - I have a build of OPEN SSL for Windows ARM64 - and this allows the pip install of cryptography to progress without error - but after installing, the library does not seem to function, and throws errors upon trying to use in a project:

from cryptography.hazmat.bindings._rust import exceptions as rust_exceptions
ImportError: DLL load failed while importing _rust: The specified module could not be found.

My question remains the same: once configuring for the OPEN SSL lib, what is the process to build the Rust code from source for Windows ARM64 ? (e.g., cmake, cargo build, built in pip install, etc)

[dlech]

You could try to figure out how to statically link OpenSSL instead of dynamically linking it, or you can copy the .dll to the directory where the python3.exe is so that Windows can find it.

[alex]

To statically link, you simply set teh OPENSSL_STATIC=1 env var when building.

…

On Mon, Feb 3, 2025 at 10:38 AM David Lechner ***@***.***> wrote: You could try to figure out how to statically link OpenSSL instead of dynamically linking it, or you can copy the .dll to the directory where the python3.exe is so that Windows can find it. — Reply to this email directly, view it on GitHub <#12326 (comment)>, or unsubscribe <https://github.com/notifications/unsubscribe-auth/AAAAGBDQPLM4LA5RCOOG5HL2N6ZTPAVCNFSM6AAAAABVVLJKY2VHI2DSMVQWIX3LMV43OSLTON2WKQ3PNVWWK3TUHMZDMMZRG43TIMJSGM> . You are receiving this because you were mentioned.Message ID: ***@***.***>

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[dlech]

Thanks, I edited my previous comment to include that. And changed MD to MT to select the correct folder for OPENSSL_LIB_DIR.