Crate p256

NIST P-256 elliptic curve (a.k.a. prime256v1, secp256r1)

⚠️ 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!

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), it's included in the US National Security Agency's "Suite B" and is widely used in protocols like TLS and the associated X.509 PKI.

Minimum Supported Rust Version

Rust 1.41 or higher.

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

Re-exports

pub use elliptic_curve;

Modules

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

Structs

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

Type Definitions

CompressedPoint	NIST P-256 Compressed Curve Point
ElementBytes	NIST P-256 Serialized Field Element.
NonZeroScalar	Non-zero scalar value.
PublicKey	NIST P-256 Public Key
SecretKey	NIST P-256 Secret Key
UncompressedPoint	NIST P-256 Uncompressed Curve Point