pirate-librustzcash/ff
Jack Grigg 00a4e1388b ff: Make byteorder an optional dependency under the std feature flag
Building ff with the std feature flag was previously broken because it
required importing byteorder functionality behind the byteorder/std
feature flag. We don't use byteorder inside ff in no_std mode, so we can
just make it optional.
2020-01-14 22:00:16 -05:00
..
ff_derive ff_derive: Fix various clippy issues 2020-01-14 21:59:45 -05:00
src no_std support for ff crate 2019-12-14 12:55:34 +00:00
.gitignore Add 'ff/' from commit '661558e0c8a5e02e08dac6530d39b2e38919aa04' 2019-01-06 09:37:22 +00:00
Cargo.toml ff: Make byteorder an optional dependency under the std feature flag 2020-01-14 22:00:16 -05:00
LICENSE-APACHE Add 'ff/' from commit '661558e0c8a5e02e08dac6530d39b2e38919aa04' 2019-01-06 09:37:22 +00:00
LICENSE-MIT Add 'ff/' from commit '661558e0c8a5e02e08dac6530d39b2e38919aa04' 2019-01-06 09:37:22 +00:00
README.md Update READMEs 2019-09-24 14:23:55 +01:00

ff

ff is a finite field library written in pure Rust, with no unsafe{} code.

Disclaimers

  • This library does not provide constant-time guarantees.

Usage

Add the ff crate to your Cargo.toml:

[dependencies]
ff = "0.4"

The ff crate contains Field, PrimeField, PrimeFieldRepr and SqrtField traits. See the documentation for more.

#![derive(PrimeField)]

If you need an implementation of a prime field, this library also provides a procedural macro that will expand into an efficient implementation of a prime field when supplied with the modulus. PrimeFieldGenerator must be an element of Fp of p-1 order, that is also quadratic nonresidue.

First, enable the derive crate feature:

[dependencies]
ff = { version = "0.4", features = ["derive"] }

And then use the macro like so:

extern crate rand;
#[macro_use]
extern crate ff;

#[derive(PrimeField)]
#[PrimeFieldModulus = "52435875175126190479447740508185965837690552500527637822603658699938581184513"]
#[PrimeFieldGenerator = "7"]
struct Fp(FpRepr);

And that's it! Fp now implements Field and PrimeField. Fp will also implement SqrtField if supported. The library implements FpRepr itself and derives PrimeFieldRepr for it.

License

Licensed under either of

at your option.

Contribution

Unless you explicitly state otherwise, any contribution intentionally submitted for inclusion in the work by you, as defined in the Apache-2.0 license, shall be dual licensed as above, without any additional terms or conditions.