Description

This PR adds the permutation function used in ripemd160 and the full hash function. Hash function construction is similar to SHA2, except uses little endian encoding.

Implementing as a precompile for Linea will be done in a separate PR when the interfaces are fixed.

Type of change

• New feature (non-breaking change which adds functionality)

How has this been tested?

• TestBlockGeneric for testing permutation function
• TestRipemd160 for testing as hash function

How has this been benchmarked?

In SCS a block cost is approx 60k PLONKish constraints. Not very specific as there is overhead for initializing the lookup table for AND/XOR/OR computation.

Checklist:

• I have performed a self-review of my code
• I have commented my code, particularly in hard-to-understand areas
• I have made corresponding changes to the documentation
• I have added tests that prove my fix is effective or that my feature works
• I did not modify files generated from templates
• golangci-lint does not output errors locally
• New and existing unit tests pass locally with my changes
• Any dependent changes have been merged and published in downstream modules