This is not a critical issue. I am just curious about the reason.
On my M1 Macbook Air, ssh-keygen can take several seconds, sometimes more than ten seconds or even dozens of seconds, to generate a public/private rsa key pair. This is much slower even than my outdated android device(One Plus 5) with Termux-app.
❯ time ssh-keygen -f /tmp/tempkey -P "" > /dev/null ssh-keygen -f /tmp/tempkey -P "" > /dev/null 3.47s user 0.02s system 99% cpu 3.493 total
However, running ssh-keygen under Rosetta is significantly better and reasonable.
❯ rm /tmp/tempkey* ❯ time arch -x86_64 ssh-keygen -f /tmp/tempkey -P "" > /dev/null arch -x86_64 ssh-keygen -f /tmp/tempkey -P "" > /dev/null 0.82s user 0.30s system 78% cpu 1.420 total
Here's info about my 'ssh-keygen`
❯ md5sum `which ssh-keygen` e884655150b3fe3ad676c84357a00b95 /usr/bin/ssh-keygen ❯ file `which ssh-keygen` /usr/bin/ssh-keygen: Mach-O universal binary with 2 architectures: [x86_64:Mach-O 64-bit executable x86_64] [arm64e] /usr/bin/ssh-keygen (for architecture x86_64): Mach-O 64-bit executable x86_64 /usr/bin/ssh-keygen (for architecture arm64e): Mach-O 64-bit executable arm64e
I tried compile three binaries from source for arm64, x86_64 and universal version(created from arm64 and x86_64 binary with
lipo). All of them run significantly faster than the built-in one.
Then, why does the built-in armed ssh-keygen run so slow ?