8318096: Introduce AsymmetricKey interface with a getParams method

Reviewed-by: darcy, mullan, ascarpino

src/java.base/share/classes/java/security/AsymmetricKey.java

@@ -0,0 +1,52 @@
+/*
+ * Copyright (c) 2023, Oracle and/or its affiliates. All rights reserved.
+ * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
+ *
+ * This code is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 only, as
+ * published by the Free Software Foundation.  Oracle designates this
+ * particular file as subject to the "Classpath" exception as provided
+ * by Oracle in the LICENSE file that accompanied this code.
+ *
+ * This code is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+ * version 2 for more details (a copy is included in the LICENSE file that
+ * accompanied this code).
+ *
+ * You should have received a copy of the GNU General Public License version
+ * 2 along with this work; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
+ * or visit www.oracle.com if you need additional information or have any
+ * questions.
+ */
+
+package java.security;
+
+import java.security.spec.AlgorithmParameterSpec;
+
+/**
+ * An asymmetric key, which can be either a public key or a private key.
+ * This interface contains methods that are common to either a public key or
+ * a private key.
+ *
+ * @since 22
+ */
+public interface AsymmetricKey extends Key {
+    /**
+     * Returns the parameters associated with this key.
+     * The parameters are optional and may be either
+     * explicitly specified or implicitly created during
+     * key pair generation.
+     *
+     * @implSpec
+     * The default implementation returns {@code null}.
+     *
+     * @return the associated parameters, may be {@code null}
+     */
+    default AlgorithmParameterSpec getParams() {
+        return null;
+    }
+}