Files
tiny-encrypt-rs/src/util_p256.rs
2023-10-15 21:43:02 +08:00

35 lines
1.5 KiB
Rust

use p256::ecdh::EphemeralSecret;
use rand::rngs::OsRng;
use rust_util::{opt_result, XResult};
use p256::pkcs8::EncodePublicKey;
use p256::{EncodedPoint, PublicKey};
use p256::elliptic_curve::sec1::FromEncodedPoint;
// use p256::elliptic_curve::sec1::{FromEncodedPoint, ToEncodedPoint};
// #[derive(Debug)]
// pub struct EphemeralKeyBytes(EncodedPoint);
//
// impl EphemeralKeyBytes {
// pub fn from_public_key(epk: &PublicKey) -> Self {
// EphemeralKeyBytes(epk.to_encoded_point(true))
// }
//
// pub fn decompress(&self) -> EncodedPoint {
// // EphemeralKeyBytes is a valid compressed encoding by construction.
// let p = PublicKey::from_encoded_point(&self.0).unwrap();
// p.to_encoded_point(false)
// }
// }
pub fn compute_shared_secret(public_key_point_hex: &str) -> XResult<(Vec<u8>, Vec<u8>)> {
let public_key_point_bytes = opt_result!(hex::decode(public_key_point_hex), "Parse public key point hex failed: {}");
let encoded_point = opt_result!(EncodedPoint::from_bytes(public_key_point_bytes), "Parse public key point failed: {}");
let public_key = PublicKey::from_encoded_point(&encoded_point).unwrap();
let esk = EphemeralSecret::random(&mut OsRng);
let epk = esk.public_key();
let shared_secret = esk.diffie_hellman(&public_key);
let epk_public_key_der = opt_result!(epk.to_public_key_der(), "Convert epk to SPKI failed: {}");
Ok((shared_secret.raw_secret_bytes().as_slice().to_vec(), epk_public_key_der.to_vec()))
}