[BUG]: macOS ARM build depends on libomp from Homebrew

[solardiz]

Which version of the application are you using?

1.9.1-ce

Description of the bug

A user reported that running macOS-ARM_1_JtR/run/dmg2john fails on not finding /opt/homebrew/opt/libomp/lib/libomp.dylib.

Steps To Reproduce

I suppose download current latest macOS ARM build from this repo and run dmg2john (or indeed john).

Your execution environment

I don't know, but a Mac that was able to run the program up to the point of not finding the library.

[solardiz]

I think we should either avoid the external dependency (preferable) or document how to satisfy it (a problematic workaround).

To avoid the dependency, is static linking an option? Or including the dynamic library in the tarball?

I haven't looked into how this build is done. Apparently, we use a compiler packaged by Homebrew? Are there other options we could use?

[claudioandre-br]

Let's deal with this in parts. BTW: It is not only libomp:

To avoid the dependency, is static linking an option? Or including the dynamic library in the tarball?

Maybe/probably. But I'm not the person to say the final word.

or document how to satisfy it (a problematic workaround).

Documentations says (https://github.com/openwall/john-packages/pkgs/container/john#-macos):

---

📂 macOS

[...]

Install required Homebrew packages (if not already installed):

 brew update
 brew install libomp openssl gmp

[...]
built using clang from the official Xcode toolchain plus non-system libraries from Homebrew.

---

------------------ Oh, I forgot about this ------------------

[claudioandre-br]

Moving forward:

The biggest problems are:

• john_omp_init() exists inside john.c
• e.g., zip2john is the "binary john". It's (part of) main() inside john.c
• so zip2john requires OMP (unless non-OMP build).

Solution?

• create a new main.c file [1];
• move the main() routine and the fallback to this new file [1];
• build main.c without OMP and SIMD [1];
• build *2john tools without OMP and SIMD;
• main.c will fallback to the *2john tools (or binaries?), OMP and SIMD binaries [1][2];

[1] This is John "proper" itself, so you need to be happy with the idea and think about its consequences for the whole project.
If you have a diagram, it's time to update it.
In fact, the first commit should be applied to the "core" branch just to see if it fits.

[2] I like the idea.

[claudioandre-br]

A user reported that running macOS-ARM_1_JtR/run/dmg2john fails on not finding /opt/homebrew/opt/libomp/lib/libomp.dylib.

• john itself will fail the same way;
• dmg2john has its own binary, so to solve the reported issue the binary must be compiled without OMP flags.