Crate eccoxide[−][src]
Expand description
Elliptic Curve Cryptography
Provide arithmetic functions to deal with elliptic curve mathematics, from the finite field arithmetics abstractions to point representation on curves.
It also provide those operations on multiples standard curves, and use when possible constant-time operations.
Currently most lowlevel arithmetics is provided by the fiat-crypto project
Example to do basic arithmetic operation with this crate:
// use p256r1 for this example, but other curve available in sec2 module
// or future other hierarchy
use eccoxide::curve::sec2::p256r1::{FieldElement, Point};
// addition in the underlying Field
let two = FieldElement::one() + FieldElement::one();
// Get the generator and add the point at infinity
let generator = Point::generator();
let same_generator = &generator + Point::infinity();
// transform the point to affine coordinate
let point = generator.to_affine().unwrap();
let (x, y) = point.to_coordinate();Using
// use p521r1 for this example
use eccoxide::curve::sec2::p521r1::{FieldElement, Scalar, Point};
use eccoxide::curve::Sign;
// this is just unsecure example, but here it could be loading some secret from disk
let bytes : [u8;66] = [1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1];
let secret_key = Scalar::from_bytes(&bytes).unwrap();
let public_key = &Point::generator() * &secret_key;
// serialize the public key to a standard-ish compress format for p521r1
let public_affine = public_key.to_affine().unwrap();
let (x, ysign) = public_affine.compress();
let format_byte : u8 = match ysign {
Sign::Positive => 0x2,
Sign::Negative => 0x3,
};
let mut public_key_bytes = Vec::new();
public_key_bytes.push(format_byte);
public_key_bytes.extend_from_slice(&x.to_bytes());