The prior-present `Ciphersuite::hash_to_F` was a sin. Implementations took a
DST, yet were not require to securely handle it. It was also biased towards the
requirements of `modular-frost` as `ciphersuite` was originally written all
those years ago, when `modular-frost` had needs exceeding what `ff`, `group`
satisfied.
Now, the hash is bound to produce an output which can be converted to a scalar
with `ff::FromUniformBytes`. A new `hash_to_F`, which accepts a single argument
of the value to hash (removing the potential to insecurely handle the DST by
removing the DST entirely). Due to `digest` yielding a `GenericArray`, yet
`FromUniformBytes` taking a `const usize`, the `ciphersuite` crate now defines
a `FromUniformBytes` trait taking an array (then implemented for all satisfiers
of `ff::FromUniformBytes`). In order to get the array type from the
`GenericArray`, the output of the hash, `digest` is updated to the `0.11`
release candidate which moves to `flexible-array` which solves that problem.
The existing, specific `hash_to_F` functions have been moved to `modular-frost`
as necessary.
`flexible-array` itself is patched to a fork due to
https://github.com/RustCrypto/hybrid-array/issues/131.
Fixes `no-std` builds for packages which intended to be `no-std` (without
`alloc`).
Updates a variety of MSRVs to 1.73 due to `flexible-transcript` no longer using
`std-shims` to achieve 1.66 (as `std-shims` requires `alloc`). A future
improvement would be for `std-shims` to have an `alloc` feature and only
provide MSRV shims without it.
flexible-transcript already had a shim to support <1.66. This was irrelevant
since flexible-transcript had a MSRV of 1.73. Due to how clunky it was, it has
been removed despite theoretically enabling an even lower MSRV.
If a crate has std set, it should enable std for all dependencies in order to
let them properly select which algorithms to use. Some crates fallback to
slower/worse algorithms on no-std.
Also more aggressively sets default-features = false leading to a *10%*
reduction in the amount of crates coordinator builds.
This will effectively add msrv protections to the entire project as almost
everything grabs from these.
Doesn't add msrv to coins as coins/bitcoin is still frozen.
Doesn't add msrv to services since cargo msrv doesn't play nice with anything
importing the runtime.
