Add derive symmetric key unit test for X25519-Deoxys-II MRAE scheme

go/common/crypto/mrae/deoxysii/asymmetric_test.go

@@ -1,13 +1,32 @@
 package deoxysii
 
 import (
+	"encoding/hex"
 	"testing"
 
+	curve25519 "github.com/oasisprotocol/curve25519-voi/primitives/x25519"
 	"github.com/oasisprotocol/deoxysii"
+	"github.com/stretchr/testify/require"
 
 	"github.com/oasisprotocol/oasis-core/go/common/crypto/mrae/api"
 )
 
+func Test_DeriveSymmetricKey(t *testing.T) {
+	// use the same test Hex string for rust at: oasis-core/runtime/src/common/crypto/mrae/deoxysii.rs
+	p, _ := hex.DecodeString("c07b151fbc1e7a11dff926111188f8d872f62eba0396da97c0a24adb75161750")
+	var privateKey [32]byte
+	copy(privateKey[:], p)
+	var publicKey [32]byte
+	curve25519.ScalarBaseMult(&publicKey, &privateKey)
+	publicKeyHex := hex.EncodeToString(publicKey[:])
+	require.EqualValues(t, publicKeyHex, "3046db3fa70ce605457dc47c48837ebd8bd0a26abfde5994d033e1ced68e2576", "derive public key")
+
+	var sharedKey [deoxysii.KeySize]byte
+	Box.DeriveSymmetricKey(sharedKey[:], &publicKey, &privateKey)
+	sharedKeyHex := hex.EncodeToString(sharedKey[:])
+	require.EqualValues(t, sharedKeyHex, "e69ac21066a8c2284e8fdc690e579af4513547b9b31dd144792c1904b45cf586", "derive symmetric key")
+}
+
 func TestDeoxysII_Box_Integration(t *testing.T) {
 	api.TestBoxIntegration(t, Box, deoxysii.New, deoxysii.KeySize)
 }

runtime/Cargo.toml

@@ -67,6 +67,7 @@ features = ["full"]
 
 [dev-dependencies]
 # For storage interoperability tests only.
+hex = "0.4"
 jsonrpc = { version = "0.12.1", features = ["simple_uds"] }
 tempfile = "3.3.0"
 

runtime/src/common/crypto/mrae/deoxysii.rs

@@ -84,12 +84,35 @@ pub fn box_open(
 
 #[cfg(test)]
 mod tests {
+    extern crate hex;
     extern crate test;
-
     use self::test::{black_box, Bencher};
     use super::*;
+    use hex::FromHex;
     use rand::RngCore;
 
+    #[test]
+    fn test_drive_symmetric_key() {
+        // use the same test Hex string for golang at: oasis-core/go/common/crypto/mrae/deoxysii/asymmetric_test.go
+        let private_key_buffer = <[u8; 32]>::from_hex(
+            "c07b151fbc1e7a11dff926111188f8d872f62eba0396da97c0a24adb75161750",
+        )
+        .expect("derive private key from hex string");
+        let private_key = x25519_dalek::StaticSecret::from(private_key_buffer);
+        let public_key = x25519_dalek::PublicKey::from(&private_key);
+        let public_key_hex = hex::encode(public_key.to_bytes());
+        assert_eq!(
+            public_key_hex,
+            "3046db3fa70ce605457dc47c48837ebd8bd0a26abfde5994d033e1ced68e2576"
+        );
+        let shared = derive_symmetric_key(&public_key.to_bytes(), &private_key.to_bytes());
+        let shared_hex = hex::encode(shared);
+        assert_eq!(
+            shared_hex,
+            "e69ac21066a8c2284e8fdc690e579af4513547b9b31dd144792c1904b45cf586"
+        );
+    }
+
     #[test]
     fn test_mrae_asymmetric() {
         let (a_pub, a_priv) = generate_key_pair(); // Alice