build.rs was using cfg(target) but it has to evaluate this from env TARGET
as build.rs cfg(target) in build context is the builder host and not the target.
This change fixes curve25519_dalek_bits lottery to determine the correct
automatic curve25119_dalek_bits with the help of platforms crate.
As discussed in #456 this also prepares for well known defaults for wasm and
arm serial backend via cfg(curve25519_dalek_bits = "64")
If the wasm32 or armv7 are going to be u64 serial by default these will be
followed up on later.
Crate features are intended to be additive, whereas only 1-of-N possible
backends can be selected.
Features can also be activated by transitive dependencies, which leads
to a problem of different dependences selecting conflicting backends.
Using `--cfg` instead moves all backend selection control to the
toplevel executable.
This commit switches to the following RUSTFLAGS to enable backends:
- `--cfg curve25519_dalek_backend="fiat"`: uses `fiat-crypto`
- `--cfg curve25519_dalek_backend="simd"`: uses nightly-only SIMD
* Restructure README and CHANGELOG
* Explain semver policy
* Specify feature flags and backends more explicitly
* Remove nightly from the CI bc that didn't belong there
* Add @pinkforest to thankyou list
Co-authored-by: pinkforest <36498018+pinkforest@users.noreply.github.com>
As proposed in #442 this makes `digest` an
optional feature that is not covered by the
SemVer public API stability guarantees.
Co-authored-by: Michael Rosenberg <michael@mrosenberg.pub>
As proposed in #442 this makes `rand_core` an
optional feature that is not covered by the
SemVer public API stability guarantees.
Co-authored-by: Michael Rosenberg <michael@mrosenberg.pub>
As proposed in #414, this commit changes the backend selection approach,
introspecting `target_pointer_width` to select `u32_backend` vs
`u64_backend` (or `fiat_u32_backend`/`fiat_u64_backend` if the
`fiat_backend` feature is enabled).
This helps eliminate the use of non-additive features, and also the
rather confusing errors that happen if multiple backends are selected
(i.e. thousands of lines of rustc errors).
The selection logic checks if `target_pointer_width = "64"` and uses the
64-bit backend, or falls back to the 32-bit backend otherwise. This
means the crate will always have a valid backend regardless of the
pointer width, although there may be odd edge cases for exotic platforms
which would optimally use the 64-bit backend but have a non-"64" target
pointer width for whatever reason. We can handle those cases as they
come up.
Renames fiat backend directory to fiat_u64 and does the additional plumbing required to make fiat_{u32, u64}_backend equal alternatives.
Adds a few comments.
https://github.com/rust-random/rand/blob/master/rand_core/CHANGELOG.md
This new version makes using rand_core on wasm seamless (thanks to the update of getrandom to v0.2)
The crate compiles well with this PR, but since some `rand_core` traits are publicly exposed in this crate's API, this is strictly speaking a breaking change.
This implementation:
- is agnostic on the hash used to pick a field element, even though SHA512 is commonly used,
- follows https://tools.ietf.org/id/draft-irtf-cfrg-hash-to-curve-10.html closely
- tests the outputs of the function using libsignal's implementation.
