Crate elliptic_curve

RustCrypto: Elliptic Curve Traits

General purpose Elliptic Curve Cryptography (ECC) support, including types and traits for representing various elliptic curve forms, scalars, points, and public/secret keys composed thereof.

Documentation

Minimum Supported Rust Version

Requires Rust 1.57 or higher.

Minimum supported Rust version can be changed in the future, but it will be done with a minor version bump.

SemVer Policy

• All on-by-default features of this library are covered by SemVer
• MSRV is considered exempt from SemVer as noted above

License

All crates licensed under either of

• Apache License, Version 2.0
• MIT license

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.

Usage

This crate provides traits for describing elliptic curves, along with types which are generic over elliptic curves which can be used as the basis of curve-agnostic code.

It’s intended to be used with the following concrete elliptic curve implementations from the RustCrypto/elliptic-curves project:

• bp256: brainpoolP256r1 and brainpoolP256t1
• bp384: brainpoolP384r1 and brainpoolP384t1
• k256: secp256k1 a.k.a. K-256
• p256: NIST P-256 a.k.a secp256r1, prime256v1
• p384: NIST P-384 a.k.a. secp384r1

The ecdsa crate provides a generic implementation of the Elliptic Curve Digital Signature Algorithm which can be used with any of the above crates, either via an external ECDSA implementation, or using native curve arithmetic where applicable.

Type conversions

The following chart illustrates the various conversions possible between the various types defined by this crate.

serde support

When the serde feature of this crate is enabled, Serialize and Deserialize impls are provided for the following types:

• [JwkEcKey]
• PublicKey
• ScalarCore

Please see type-specific documentation for more information.

Re-exports

• pub use crypto_bigint as bigint;
• pub use generic_array;
• pub use rand_core;
• pub use subtle;
• pub use zeroize;
• pub use ff;
• pub use group;

Modules

• consts
  Type aliases for many constants.
• ops
  Traits for arithmetic operations on elliptic curve field elements.
• sec1
  Support for SEC1 elliptic curve encoding formats.
• weierstrass
  Complete projective formulas for prime order elliptic curves as described in Renes-Costello-Batina 2015.

Macros

• impl_field_element
  Provides both inherent and trait impls for a field element type which are backed by a core set of arithmetic functions specified as macro arguments.
• impl_field_op
  Emit impls for a core::ops trait for all combinations of reference types, which thunk to the given function.

Structs

• Error
  Elliptic curve errors.
• NonZeroScalar
  Non-zero scalar type.
• PublicKey
  Elliptic curve public keys.
• ScalarCore
  Generic scalar type with core functionality.
• SecretKey
  Elliptic curve secret keys.

Traits

• AffineArithmetic
  Elliptic curve with affine arithmetic implementation.
• AffineXCoordinate
  Obtain the affine x-coordinate of an elliptic curve point.
• Curve
  Elliptic curve.
• DecompactPoint
  Decompact an elliptic curve point from an x-coordinate.
• DecompressPoint
  Decompress an elliptic curve point.
• Field
  This trait represents an element of a field.
• Group
  This trait represents an element of a cryptographic group.
• IsHigh
  Is this scalar greater than n / 2?
• PointCompaction
  Point compaction settings.
• PointCompression
  Point compression settings.
• PrimeCurve
  Marker trait for elliptic curves with prime order.
• PrimeCurveArithmetic
  Prime order elliptic curve with projective arithmetic implementation.
• PrimeField
  This represents an element of a prime field.
• ProjectiveArithmetic
  Elliptic curve with projective arithmetic implementation.
• ScalarArithmetic
  Scalar arithmetic.

Type Definitions

• AffinePoint
  Affine point type for a given curve with a ProjectiveArithmetic implementation.
• FieldBytes
  Byte representation of a base/scalar field element of a given curve.
• FieldSize
  Size of field elements of this elliptic curve.
• ProjectivePoint
  Projective point type for a given curve with a ProjectiveArithmetic implementation.
• Result
  Result type with the elliptic-curve crate’s Error type.
• Scalar
  Scalar field element for a particular elliptic curve.