Add support for X25519 algorithm alias to XDH

common/src/main/java/org/conscrypt/OpenSSLProvider.java

@@ -198,6 +198,7 @@ public OpenSSLProvider(String providerName) {
 
         put("KeyPairGenerator.XDH", PREFIX + "OpenSSLXDHKeyPairGenerator");
         put("Alg.Alias.KeyPairGenerator.1.3.101.110", "XDH");
+        put("Alg.Alias.KeyPairGenerator.X25519", "XDH");
 
         /* == KeyFactory == */
         put("KeyFactory.RSA", PREFIX + "OpenSSLRSAKeyFactory");
@@ -211,6 +212,7 @@ public OpenSSLProvider(String providerName) {
 
         put("KeyFactory.XDH", PREFIX + "OpenSSLXDHKeyFactory");
         put("Alg.Alias.KeyFactory.1.3.101.110", "XDH");
+        put("Alg.Alias.KeyFactory.X25519", "XDH");
 
         /* == SecretKeyFactory == */
         put("SecretKeyFactory.DESEDE", PREFIX + "DESEDESecretKeyFactory");
@@ -624,6 +626,8 @@ private void putXDHKeyAgreementImplClass(String className) {
                 PREFIX + className,
                 supportedKeyClasses,
                 supportedKeyFormats);
+
+        put("Alg.Alias.KeyAgreement.X25519", "XDH");
     }
 
     private void putImplClassWithKeyConstraints(String typeAndAlgName,

common/src/main/java/org/conscrypt/OpenSSLXDHKeyFactory.java

@@ -81,8 +81,9 @@ protected <T extends KeySpec> T engineGetKeySpec(Key key, Class<T> keySpec)
             throw new InvalidKeySpecException("keySpec == null");
         }
 
-        if (!"XDH".equals(key.getAlgorithm())) {
-            throw new InvalidKeySpecException("Key must be an XDH key");
+        // Support XDH or X25519 algorithm names per JEP 324
+        if (!"XDH".equals(key.getAlgorithm()) || !"X25519".equals(key.getAlgorithm()) ) {
+            throw new InvalidKeySpecException("Key must be an XDH or X25519 key");
         }
 
         Class<?> publicKeySpec = getJavaPublicKeySpec();

common/src/test/java/org/conscrypt/javax/crypto/X25519KeyAgreementTest.java

@@ -0,0 +1,28 @@
+package org.conscrypt.javax.crypto;
+
+import static org.junit.Assert.assertArrayEquals;
+
+import java.security.KeyFactory;
+import java.security.PrivateKey;
+import java.security.Provider;
+import java.security.PublicKey;
+import java.security.Security;
+import java.security.spec.PKCS8EncodedKeySpec;
+import java.security.spec.X509EncodedKeySpec;
+import javax.crypto.KeyAgreement;
+import org.junit.Test;
+import org.junit.runner.RunWith;
+import org.junit.runners.JUnit4;
+
+
+/**
+ * Tests for all registered X25519 {@link KeyAgreement} providers.
+ */
+@RunWith(JUnit4.class)
+public class X25519KeyAgreementTest extends XDHKeyAgreementTest {
+
+    @Override
+    protected String getAlgorithm() {
+        return "X25519";
+    }
+}

common/src/test/java/org/conscrypt/javax/crypto/XDHKeyAgreementTest.java

@@ -59,7 +59,7 @@ public class XDHKeyAgreementTest {
     private PublicKey rfc7748X25519PublicKey;
 
     private void setupKeys(Provider p) throws Exception {
-        KeyFactory kf = KeyFactory.getInstance("XDH", p);
+        KeyFactory kf = KeyFactory.getInstance(getAlgorithm(), p);
 
         byte[] privateKey;
         if ("SunEC".equalsIgnoreCase(p.getName())
@@ -84,15 +84,20 @@ private void setupKeys(Provider p) throws Exception {
 
     @Test
     public void test_XDHKeyAgreement() throws Exception {
-        for (Provider p : Security.getProviders("KeyAgreement.XDH")) {
+        final String keyAgreementAlgorithm = String.format("KeyAgreement.%s", getAlgorithm());
+        for (Provider p : Security.getProviders(keyAgreementAlgorithm)) {
             setupKeys(p);
 
-            KeyAgreement ka = KeyAgreement.getInstance("XDH", p);
+            KeyAgreement ka = KeyAgreement.getInstance(getAlgorithm(), p);
 
             test_x25519_keyAgreement_rfc7748_kat_success(ka);
         }
     }
 
+    protected String getAlgorithm() {
+        return "XDH";
+    }
+
     private void test_x25519_keyAgreement_rfc7748_kat_success(KeyAgreement ka) throws Exception {
         ka.init(rfc7748X25519PrivateKey);
         ka.doPhase(rfc7748X25519PublicKey, true);