Poly1305

[tarcieri]

Seems like we have fairly reasonable ChaCha20 crates and Salsa20 crates now, and I see newpavlov snagged https://crates.io/crates/poly1305

A poly1305 crate seems like the next logical step, but where should it go? Right now I think the closest fit is https://github.com/RustCrypto/hashes but that seems a little weird

Should we stick it under hashes, or do we need a new toplevel project like universal-hashes or one-time-authenticators?

As it were, I have a mostly complete (but completely untested) Rust implementation of POLYVAL that needs a home and could be located in the same place: https://github.com/miscreant/miscreant.rs/blob/047ae8b3fd68d62eeb1e8510110439ba24473df3/src/polyval.rs

[newpavlov]

Shouldn't it go to the RustCrypto/MACs repo? It's already listed in RustCrypto/MACs#1.

[tarcieri]

@newpavlov I guess that works, except Poly1305 in and of itself is not a MAC... to be used as a MAC in and of itself it needs to be paired with a cipher ala Poly1305-AES (ditto for POLYVAL/GHASH vs GMAC)

Given the main use is as a building block for a MAC, I suppose RustCrypto/MAC is the best place. I just worry someone will try to abuse a universal hash function as a MAC, but perhaps we can appropriately label them.

[newpavlov]

Can't we implement Mac trait only for a structure generic over StreamCipher/BlockCipher? I don't have exact API in mind, but I think it should be doable.

[tarcieri]

@newpavlov sure, that sounds good.

[tarcieri]

PR to add Poly1305 to RustCrypto/MACs here: RustCrypto/MACs#12