cksum: Fix -a blake3/shake*

[oech3]

I really want remove them completely since it has a maintainance cost, but broken cksum is one of a blocker for hashsum deletion. So I fix it.

Closes #10002

[github-actions]

GNU testsuite comparison:

Skipping an intermittent issue tests/shuf/shuf-reservoir (passes in this run but fails in the 'main' branch)
Skipping an intermittent issue tests/sort/sort-stale-thread-mem (passes in this run but fails in the 'main' branch)
Skipping an intermittent issue tests/tail/inotify-dir-recreate (passes in this run but fails in the 'main' branch)

[codspeed-hq]

Merging this PR will degrade performance by 99.77%

❌ 1 regressed benchmark
✅ 283 untouched benchmarks
⏩ 38 skipped benchmarks¹

⚠️ Please fix the performance issues or acknowledge them on CodSpeed.

Performance Changes

	Mode	Benchmark	BASE	HEAD	Efficiency
❌	Simulation	cksum_blake3	215.7 µs	93,209.5 µs	-99.77%

---

_{Comparing oech3:ckb3 (061f3f3) with main (da7ad84)}

Footnotes

1. 38 benchmarks were skipped, so the baseline results were used instead. If they were deleted from the codebase, click here and archive them to remove them from the performance reports. ↩

[oech3]

Note that we are benchmarking a bunch of errors currently. So regression is not happening.

[github-actions]

GNU testsuite comparison:

GNU test failed: tests/ls/abmon-align. tests/ls/abmon-align is passing on 'main'. Maybe you have to rebase?
Skip an intermittent issue tests/tty/tty-eof (fails in this run but passes in the 'main' branch)

[oech3]

ok?

[RenjiSann]

Can you add some tests for this in test_cksum.rs ?

[github-actions]

GNU testsuite comparison:

GNU test failed: tests/cp/nfs-removal-race. tests/cp/nfs-removal-race is passing on 'main'. Maybe you have to rebase?
Note: The gnu test tests/runcon/runcon-compute is now being skipped but was previously passing.

[github-actions]

GNU testsuite comparison:

Congrats! The gnu test tests/printf/printf-surprise is now passing!

[github-actions]

GNU testsuite comparison:

GNU test failed: tests/tail/symlink. tests/tail/symlink is passing on 'main'. Maybe you have to rebase?
Skip an intermittent issue tests/shuf/shuf-reservoir (fails in this run but passes in the 'main' branch)
Skip an intermittent issue tests/sort/sort-stale-thread-mem (fails in this run but passes in the 'main' branch)

[oech3]

Typo...

[oech3]

Failing test is tac. So this PR is ready.

[RenjiSann]

Is there a reason why we require a --length argument for shake* algorithms, even though it's not used to compute the digest underneath ?

[oech3]

shake* is XOF. Does not our cksum support it?

[RenjiSann]

shake* is XOF. Does not our cksum support it?

Well I fear it does not, see

coreutils/src/uucore/src/lib/features/sum.rs

Lines 420 to 421 in ba1afb0

	impl_digest_shake!(Shake128, 256);
	impl_digest_shake!(Shake256, 512);

[oech3]

Oops... We can leave frozen length as a bug and split PR...

[oech3]

Without adding code, I have

$ target/debug/cksum -a shake128 /dev/null
cksum: --length required for 'SHAKE128'
$ target/debug/cksum -a shake128 -l 128 /dev/null
cksum: --length is only supported with --algorithm blake2b, sha2, or sha3

[github-actions]

GNU testsuite comparison:

Skipping an intermittent issue tests/misc/usage_vs_getopt (passes in this run but fails in the 'main' branch)
Skipping an intermittent issue tests/shuf/shuf-reservoir (passes in this run but fails in the 'main' branch)
Skipping an intermittent issue tests/sort/sort-stale-thread-mem (passes in this run but fails in the 'main' branch)

[github-actions]

GNU testsuite comparison:

Congrats! The gnu test tests/factor/t26 is no longer failing!

[oech3]

@RenjiSann OK to close this PR as replaced?

[RenjiSann]

It is still relevant for blake3, but we can do it somewhere else, yes 👍

[oech3]

Personally, I think non-GNU (reference) XOF function is unnecessary complexity for us. It is really unclear how to write tags and determine (default) length...