Crate p256

Pure Rust implementation of the NIST P-256 elliptic curve, including support for the Elliptic Curve Digital Signature Algorithm (ECDSA), Elliptic Curve Diffie-Hellman (ECDH), and general purpose elliptic curve/field arithmetic which can be used to implement protocols based on group operations.

About NIST P-256

NIST P-256 is a Weierstrass curve specified in FIPS 186-4: Digital Signature Standard (DSS):

https://nvlpubs.nist.gov/nistpubs/FIPS/NIST.FIPS.186-4.pdf

Also known as prime256v1 (ANSI X9.62) and secp256r1 (SECG), P-256 is included in the US National Security Agency's "Suite B" and is widely used in Internet and connected device protocols like TLS, the X.509 PKI, and Bluetooth.

⚠️ Security Warning

The elliptic curve arithmetic contained in this crate has never been independently audited!

This crate has been designed with the goal of ensuring that secret-dependent operations are performed in constant time (using the subtle crate and constant-time formulas). However, it has not been thoroughly assessed to ensure that generated assembly is constant time on common CPU architectures.

USE AT YOUR OWN RISK!

Minimum Supported Rust Version

Rust 1.46 or higher.

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

Re-exports

pub use elliptic_curve;

pub use elliptic_curve::pkcs8;

Modules

ecdh	ecdh Elliptic Curve Diffie-Hellman (Ephemeral) Support.
ecdsa	ecdsa-core Elliptic Curve Digital Signature Algorithm (ECDSA)
test_vectors	test-vectors secp256r1 test vectors.

Structs

AffinePoint	arithmetic A point on the secp256r1 curve in affine coordinates.
BlindedScalar	arithmetic Scalar blinded with a randomly generated masking value.
NistP256	NIST P-256 elliptic curve.
ProjectivePoint	arithmetic A point on the secp256r1 curve in projective coordinates.
Scalar	arithmetic An element in the finite field modulo n.

Type Definitions

EncodedPoint	NIST P-256 SEC1 encoded point.
FieldBytes	NIST P-256 field element serialized as bytes.
NonZeroScalar	Non-zero scalar value.
PublicKey	NIST P-256 public key.
ScalarBits	NIST P-256 field element serialized as bits.
SecretBytes	zeroize Bytes containing a NIST P-256 secret scalar
SecretKey	zeroize NIST P-256 secret key.