feat(stdlib)!: Adding Mimc Sponge to stdlib

[seugu]

Description

Problem*

Resolves

Summary*

Documentation

• This PR requires documentation updates when merged.

  • I will submit a noir-lang/docs PR.
  • I will request for and support Dev Rel's help in documenting this PR.

Additional Context

PR Checklist*

• I have tested the changes locally.
• I have formatted the changes with Prettier and/or cargo fmt on default settings.

[kevaundray]

Hi,

Thank you for your contribution!

Can you update the description to accurately describe the changes being made in this PR, ie why files were moved, why we need the sponge variation etc?

[TomAFrench]

This is currently a breaking change. Can you please undo moving the existing mimc functions?

[kevaundray]

This is currently a breaking change. Can you please undo moving the existing mimc functions?

Perhaps its better to just change the PR title because it makes sense to move it to its own file

[vezenovm]

@TomAFrench I changed the title to a breaking change as I do think moving the mimc functions to their own file makes sense. Especially when the impls require long lists of constants

[vezenovm]

@seugu you need to update the import in a couple tests that you can see failing in the CI.

Could you also add a test for MiMCSponge that checks the output of some simple outputs. There are similar tests for hash functions like sha256 under crates/nargo_cli/tests/execution_success which you can follow. The test will just be a simple Noir program.

[TomAFrench]

I can't really validate the correctness of the implementation so I'll approve if someone on the team vouches for it.

That said, I think this goes against our aims in #1258. This would be best as a mimc library.

[vezenovm]

That said, I think this goes against our aims in #1258. This would be best as a mimc library.

I recommended for this to be put in the standard lib as MiMC is common hash function that should not be changing much and we already have MiMC7 inside of the stdlib. I forgot about the issue and aims listed in #1258, but perhaps this can just be moved out once we have some type of hashes library under noir-lang. If we feel strongly this should remain outside of Noir, we can ask @seugu to turn his Noir-MiMCSponge repo into a library.

The implementation is correct from my review and checks against the circom implementations.

[vezenovm]

@seugu It looks like you are using an old version of nargo for the new tests you included under execution_success. The projects are missing the name and type fields in the Nargo.toml.

[TomAFrench]

I'm closing this PR as the mimc implementation has been moved to an external library: https://github.com/noir-lang/mimc