feat: add curve25519

__crypto/curve25519/src/main.rs

@@ -0,0 +1,28 @@
+use rand::rngs::OsRng;
+use ed25519_dalek::{ Keypair, Signer, Verifier };
+use x25519_dalek::{EphemeralSecret, PublicKey};
+
+fn main() {
+    let mut csprng = OsRng{};
+    let keypair = Keypair::generate(&mut csprng);
+    println!("Key pair: {:#?}", keypair);
+
+    let message = b"This is sign test message.";
+    let signature = keypair.sign(message);
+    println!("Signature: {}", hex::encode(signature));
+
+    let public_key = keypair.public;
+    println!("Verify result: {:?}", public_key.verify(message, &signature));
+
+    // key exchange
+    let alice_secret = EphemeralSecret::new(OsRng);
+    let alice_public = PublicKey::from(&alice_secret);
+    let bob_secret = EphemeralSecret::new(OsRng);
+    let bob_public = PublicKey::from(&bob_secret);
+    
+    let alice_shared_secret = alice_secret.diffie_hellman(&bob_public);
+    let bob_shared_secret = bob_secret.diffie_hellman(&alice_public);
+
+    println!("Alice shared secret: {}", hex::encode(alice_shared_secret.as_bytes()));
+    println!("Bob   shared secret: {}", hex::encode(bob_shared_secret.as_bytes()));
+}