Trait Curve

pub trait Curve {
    const MOD_LENGTH: u2;
    const SCALAR_LENGTH: u2;
    const MODULO_P: &'static [u8];
    const A_CURVE: &'static [u8];
    const B_CURVE: &'static [u8];
    const BASE_POINT_A_X: &'static [u8];
    const BASE_POINT_A_Y: &'static [u8];
    const BASE_POINT_A_Z: &'static [u8];
    const ORDER_POINT: &'static [u8];
    const CNS: &'static [u8];

    // Provided method
    fn verify_curve() -> Result<(), CurveVerificationFailure> { ... }
}

A trait that generalizes over a curve concept.

General equation of a curve is: y^2 = x^3 + a*x + b

Provides all the parametrizations through associated constants.

Associated constant slices must incorporate zero padding required by PUKCC.

Const generics are limited. It is impossible to have const arrays with a length as a separate const parameter. Therefore slices are used instead and length verification is moved to runtime (Curve::verify_curve)

Required Associated Constants

const MOD_LENGTH: u2

Length of P modulus (bytes)

const SCALAR_LENGTH: u2

Length of the scalar (bytes)

const MODULO_P: &'static [u8]

P modulus parameter Length: MOD_LENGTH + 4

const A_CURVE: &'static [u8]

A parameter of a curve Length: MOD_LENGTH + 4

const B_CURVE: &'static [u8]

B parameter of a curve Length: MOD_LENGTH + 4

const BASE_POINT_A_X: &'static [u8]

X coordinate of a base point (point of origin on a curve) Length: MOD_LENGTH + 4

const BASE_POINT_A_Y: &'static [u8]

Y coordinate of a base point (point of origin on a curve) Length: MOD_LENGTH + 4

const BASE_POINT_A_Z: &'static [u8]

Z coordinate of a base point (point of origin on a curve) It is equal to 1 Length: MOD_LENGTH + 4

const ORDER_POINT: &'static [u8]

Order point of the curve Length: SCALAR_LENGTH + 4

const CNS: &'static [u8]

Modulo reduction constant precalculated with RedMod service in a SetupConstant mode

Note: That CNS value is for services over prime field: GF(p) For polynomials GF(2^n) it has to be generated separately Length: SCALAR_LENGTH + 12

Provided Methods

fn verify_curve() -> Result<(), CurveVerificationFailure>

Function that can be used during runtime to verify if a curve is correctly defined.

That is:

• lengths of slices are following the requirements
• slices are 4 aligned

Dyn Compatibility

This trait is not dyn compatible.

In older versions of Rust, dyn compatibility was called "object safety", so this trait is not object safe.

Implementors

impl Curve for Nist256p

const MOD_LENGTH: u2 = 32u16

const SCALAR_LENGTH: u2 = 32u16

const MODULO_P: &'static [u8]

const A_CURVE: &'static [u8]

const B_CURVE: &'static [u8]

const BASE_POINT_A_X: &'static [u8]

const BASE_POINT_A_Y: &'static [u8]

const BASE_POINT_A_Z: &'static [u8]

const ORDER_POINT: &'static [u8]

const CNS: &'static [u8]