* Vendor lizard hash to curve from Signal
* Add invalid Lizard encoding test
* Added lizard details to readme and changelog
* Upgrade ristretto.sage to Python3
* Add lizard test vector generation to ristretto.sage
* Added map_to_curve and its inverse
* Use CtOption instead of bitmasks; other cleanup
* Add README to lizard folder
* Split map_to_curve into map_to_curve and map_to_curve_restricted; make its inverse return 16 elements
* Consolidate Ristretto Elligator functions into its own file
* Rename hash_to_curve as encode_to_curve
* Implement the inline description of the standard.
* Generalise map_to_field to return an arbitrary number of field elements.
* Implement hash_to_curve as defined in the standard.
* Put elligator behind the "digest" feature.
* Add warning on non-uniformity of `encode_to_curve`.
* Remove the need of Vec for hash_to_field.
* Apply suggestions from code review
* Refactor expand_message_xmd out of hash_to_field
* Add hash-to-curve to benches
* Constraint COUNT to 1 or 2; add note on secure hash function usage
* Correct hash function usage in encode- and hash-to-curve
---------
Co-authored-by: Armando Faz <armfazh@users.noreply.github.com>
Co-authored-by: Michael Rosenberg <mrosenberg@cloudflare.com>
This represents the first breaking change in a new release series,
bumping all crates to the 2024 edition of Rust.
As such, the version numbers of all crates have been incremented to
represent a new prerelease series:
- `curve25519-dalek`: v5.0.0-pre
- `ed25519-dalek`: v3.0.0-pre
- `x25519-dalek`: v3.0.0-pre
Note that this commit isn't intended to cut associated crate releases of
these on crates.io, but is merely bumping the version numbers to denote
there are pending breaking changes.
This commit also includes rustfmt changes which were made as part of the
2024 edition.
Also includes clippy fixes.
* Implementation of `hash_to_field` as defined in the standard
* Implementation of `hash_to_curve` as defined in the standard, by changing the mechanism over which we chose the sign.
* For the point above, had to change the `elligator_encode` to return whether `eps` is a square or not (required for `hash_to_curve`).
* Included test vectors of the draft.
* Included `FieldElement::from_bytes_wide(bytes: &u8; 64])` to reduce integers encoded in 64 bytes.
* curve: rename `FieldElement*::as_bytes` => `::to_bytes`
Methods named `as_*` should perform a zero-cost borrowing conversion:
https://rust-lang.github.io/api-guidelines/naming.html#ad-hoc-conversions-follow-as_-to_-into_-conventions-c-conv
Methods named `to_*` can perform an expensive owned conversion.
Since the `FieldElement*` types are technically part of the public API
(but feature gated), this also preserves the old names with a
deprecation. We can remove them in the next breaking release.
The same change was also made to the backend `Scalar*` types, however
these types are not a part of the public API.
Adds a lints section to the top of lib.rs with the following:
#![warn(
clippy::unwrap_used,
missing_docs,
rust_2018_idioms,
unused_lifetimes,
unused_qualifications
)]
`warn` is used instead of `deny` to prevent the lints from firing during
local development, however we already configure `-D warnings` in CI so
if any lint fails on checked-in code, it will cause a CI failure.
This commit also fixes or explicitly allows any current violations of
these lints. The main ones were:
- `clippy::unwrap_used`: replaces usages of `unwrap` with `expect`
- `rust_2018_idioms`: no implicit lifetimes, which were present on
usages of `core::fmt::Formatter`
