Module pka 

Public key accelerator.

The driver runs on the PKA engine of the CryptoCell (nRF52840, nRF91, nRF5340) or the public key engine of CRACEN (nRF54L). It provides:

• ECDSA signature generation and verification.
• ECDH and public key derivation, through scalar multiplication of a curve point.
• RSA, through modular exponentiation, with or without the Chinese remainder theorem.

Curve points, scalars, moduli and signatures are big-endian byte slices, as in SEC 1 and PKCS#1.

• Every value of a curve operation must be exactly Curve::size bytes long. Pad it with zeros on the left if needed.
• Every value of an RSA operation must be at most as long as the modulus.

Example

use embassy_nrf::crypto::pka::{Pka, PointMut, curve};

// On CRACEN (nRF54L) the constructor also takes the engine microcode.
let mut pka = Pka::new_blocking(p.CRYPTO_PKA);

// Derive the public key of a private key.
let mut x = [0; 32];
let mut y = [0; 32];
pka.blocking_public_key(&curve::NIST_P256, &private_key, PointMut { x: &mut x, y: &mut y })?;

Modules

curve

Domain parameters of common elliptic curves.

Structs

Curve

Domain parameters of a short Weierstrass curve y² = x³ + a·x + b over a prime field.

Pka

Driver for the public key accelerator.

Point

A curve point in affine coordinates.

PointMut

Buffers receiving a curve point in affine coordinates.

Signature

An ECDSA signature.

SignatureMut

Buffers receiving an ECDSA signature.

Enums

Error

PKA error.

Constants

MAX_CURVE_LEN

Largest curve size in bytes that the driver accepts. This fits NIST P-521.

MAX_MODULUS_LEN

Largest modulus in bytes that the driver accepts. This fits RSA-4096.