96d1ce5 crypto: Add ECDH trait and `MemorySigner` impl — heartwood

Radicle Heartwood Protocol & Stack

crypto: Add ECDH trait and `MemorySigner` impl

Alexis Sellier committed 3 years ago

commit 96d1ce5da665ee88cacbc73f35f871d8231255e2
parent 66d76d7ab26a69b176f7c8ce5788a53c106e0491

2 files changed +21 -1

modified radicle-crypto/src/lib.rs

@@ -26,6 +26,9 @@ pub struct Verified;

 #[derive(Debug, Copy, Clone, PartialEq, Eq)]
 pub struct Unverified;
 /// Output of a Diffie-Hellman key exchange.
 pub type SharedSecret = [u8; 32];
 /// Error returned if signing fails, eg. due to an HSM or KMS.
 #[derive(Debug, Error)]
 #[error(transparent)]

@@ -69,6 +72,13 @@ where

     }
 }
 /// A signer that can perform Elliptic-curve Diffie–Hellman.
 pub trait Ecdh: Signer {
     /// Perform an ECDH key exchange. Takes the counter-party's public key,
     /// and returns a computed shared secret.
     fn ecdh(&self, other: &PublicKey) -> Result<SharedSecret, Error>;
 }
 /// Cryptographic signature.
 #[derive(PartialEq, Eq, Hash, Copy, Clone, Serialize, Deserialize)]
 #[serde(into = "String", try_from = "String")]

modified radicle-crypto/src/ssh/keystore.rs

@@ -5,7 +5,7 @@ use std::{fs, io};

 use thiserror::Error;
 use zeroize::Zeroizing;
 use crate::{keypair, PublicKey, SecretKey, Signature, Signer, SignerError};
 use crate::{keypair, Ecdh, PublicKey, SecretKey, SharedSecret, Signature, Signer, SignerError};
 /// A secret key passphrase.
 pub type Passphrase = Zeroizing<String>;

@@ -139,6 +139,16 @@ impl Signer for MemorySigner {

     }
 }
 impl Ecdh for MemorySigner {
     fn ecdh(&self, other: &PublicKey) -> Result<SharedSecret, ed25519_compact::Error> {
         let pk = ed25519_compact::x25519::PublicKey::from_ed25519(other)?;
         let sk = ed25519_compact::x25519::SecretKey::from_ed25519(&self.secret)?;
         let ss = pk.dh(&sk)?;
         Ok(*ss)
     }
 }
 impl MemorySigner {
     /// Load this signer from a keystore, given a secret key passphrase.
     pub fn load(keystore: &Keystore, passphrase: Passphrase) -> Result<Self, MemorySignerError> {