8171277: Elliptic Curves for Security in Crypto

Implementations of X25519 and X448 key agreement in SunEC

Reviewed-by: mullan

src/java.base/share/classes/java/security/spec/XECPrivateKeySpec.java

@@ -0,0 +1,82 @@
+/*
+ * Copyright (c) 2018, 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.spec;
+
+import java.util.Objects;
+
+/**
+ * A class representing elliptic curve private keys as defined in RFC 7748,
+ * including the curve and other algorithm parameters. The private key is
+ * represented as an encoded scalar value. The decoding procedure defined in
+ * the RFC includes an operation that forces certain bits of the key to either
+ * 1 or 0. This operation is known as "pruning" or "clamping" the private key.
+ * All arrays in this spec are unpruned, and implementations will need to prune
+ * the array before using it in any numerical operations.
+ *
+ * @since 11
+ */
+public class XECPrivateKeySpec implements KeySpec {
+
+    private final AlgorithmParameterSpec params;
+    private final byte[] scalar;
+
+    /**
+     * Construct a private key spec using the supplied parameters and
+     * encoded scalar value.
+     *
+     * @param params the algorithm parameters
+     * @param scalar the unpruned encoded scalar value. This array is copied
+     *               to protect against subsequent modification.
+     *
+     * @throws NullPointerException if {@code params} or {@code scalar}
+     *                              is null.
+     */
+    public XECPrivateKeySpec(AlgorithmParameterSpec params, byte[] scalar) {
+        Objects.requireNonNull(params, "params must not be null");
+        Objects.requireNonNull(scalar, "scalar must not be null");
+
+        this.params = params;
+        this.scalar = scalar.clone();
+    }
+
+    /**
+     * Get the algorithm parameters that define the curve and other settings.
+     *
+     * @return the algorithm parameters
+     */
+    public AlgorithmParameterSpec getParams() {
+        return params;
+    }
+
+    /**
+     * Get the scalar value encoded as an unpruned byte array. A new copy of
+     * the array is returned each time this method is called.
+     *
+     * @return the unpruned encoded scalar value
+     */
+    public byte[] getScalar() {
+        return scalar.clone();
+    }
+}