Update RPO's padding rule to use that in the xHash paper

[Al-Kindi-0]

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• Repo forked and branch created from next according to naming convention.
• Commit messages and codestyle follow conventions.
• Relevant issues are linked in the PR description.
• Tests added for new functionality.
• Documentation/comments updated according to changes.

[sonarcloud[bot]]

Quality Gate passed

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[Al-Kindi-0]

On potential thing left to consider: I believe currently hashing of empty list of elements and hashing of 8 ZERO elements will give us the same result - right? I wonder if there is a good way to fix this - just in case. Nothing immediately comes to mind though.

I think we had a similar discussion in RPO and I believe we settled on not accepting empty lists for hashing. I will think about it again to see if we can accommodate it differently.

[bobbinth]

@Al-Kindi-0 - let's rebase this PR.

Also, should we implement the rule where hashing of an empty string gives us [ZERO; 4] output?

[Al-Kindi-0]

@Al-Kindi-0 - let's rebase this PR.

Also, should we implement the rule where hashing of an empty string gives us [ZERO; 4] output?

Done!

[Al-Kindi-0]

Also, it seems like the "return default digest on empty input" as already working here, right?

Yes, had to check the bytes case, but even then it worked without complications

Lastly, could you refresh 0xPolygonMiden/miden-vm#1343 when you get a chance?

Sure thing

[sonarcloud[bot]]

Quality Gate passed

Issues
0 New issues
0 Accepted issues

Measures
0 Security Hotspots
0.0% Coverage on New Code
0.0% Duplication on New Code

See analysis details on SonarCloud