tpmutil: Fix integer casting on 32-bit platforms

[josephlr]

We need to make sure we only cast to ints once we are sure the value is
within the appropriate range (otherwise the value will wrap causing
errors).

Fixes #252

Signed-off-by: Joe Richey joerichey@google.com

[josephlr]

CC: @davide125 can you confirm this fixes your issue

[josephlr]

I can confirm that GOARCH=386 go test ./... panicked before this change, and now no longer panics.

I would add test with GOARCH=386 to our CI, but:

• Getting CGO stuff to work on a cross-compiled build is a pain
• Even if you set CGO_CFLAGS=-m32 GOARCH=386 CGO_ENABLED=1, the build still fails because you also need a 32-bit version of OpenSSL's libcrypto
• I don't know how to install a 32-bit version of libcrypto (or even if the distros still carry it).
• I don't know how to have the -lcrypto flag conditionally point to the 32-bit version.

So it doesn't seem worth the effort for such an obscure target.

[davide125]

Yep, that worked, thanks! You can see the full logs here: https://koji.fedoraproject.org/koji/taskinfo?taskID=70624896

wrt testing on different arches, one thing you may wanna look into is https://packit.dev/docs/guide/ which allows running CI jobs against all Fedora-supported architectures. I do agree it's probably not worth the trouble just for this though.

[chrisfenner]

LGTM