jdk/src/share/classes/sun/security/ec/ECKeyPairGenerator.java
changeset 3492 e549cea58864
child 3863 8e0f58b1c072
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/jdk/src/share/classes/sun/security/ec/ECKeyPairGenerator.java	Tue Aug 11 16:52:26 2009 +0100
@@ -0,0 +1,191 @@
+/*
+ * Copyright 2009 Sun Microsystems, Inc.  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.  Sun designates this
+ * particular file as subject to the "Classpath" exception as provided
+ * by Sun 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 Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
+ * CA 95054 USA or visit www.sun.com if you need additional information or
+ * have any questions.
+ */
+
+package sun.security.ec;
+
+import java.math.BigInteger;
+import java.security.*;
+import java.security.spec.AlgorithmParameterSpec;
+import java.security.spec.ECGenParameterSpec;
+import java.security.spec.ECParameterSpec;
+import java.security.spec.ECPoint;
+
+import sun.security.ec.NamedCurve;
+import sun.security.ec.ECParameters;
+import sun.security.ec.ECPrivateKeyImpl;
+import sun.security.ec.ECPublicKeyImpl;
+import sun.security.jca.JCAUtil;
+
+/**
+ * EC keypair generator.
+ * Standard algorithm, minimum key length is 112 bits, maximum is 571 bits.
+ *
+ * @since 1.7
+ */
+public final class ECKeyPairGenerator extends KeyPairGeneratorSpi {
+
+    // flag indicating whether the native ECC implementation is present
+    private static boolean implementationPresent = true;
+    static {
+        try {
+            AccessController.doPrivileged(new PrivilegedAction<Void>() {
+                public Void run() {
+                    System.loadLibrary("sunecc");
+                    return null;
+                }
+            });
+        } catch (UnsatisfiedLinkError e) {
+            implementationPresent = false;
+        }
+    }
+    private static final int KEY_SIZE_MIN = 112; // min bits (see ecc_impl.h)
+    private static final int KEY_SIZE_MAX = 571; // max bits (see ecc_impl.h)
+    private static final int KEY_SIZE_DEFAULT = 256;
+
+    // used to seed the keypair generator
+    private SecureRandom random;
+
+    // size of the key to generate, KEY_SIZE_MIN <= keySize <= KEY_SIZE_MAX
+    private int keySize;
+
+    // parameters specified via init, if any
+    private AlgorithmParameterSpec params = null;
+
+    /**
+     * Constructs a new ECKeyPairGenerator.
+     *
+     * @exception ProviderException if the native ECC library is unavailable.
+     */
+    public ECKeyPairGenerator() {
+        if (!implementationPresent) {
+            throw new ProviderException("EC implementation is not available");
+        }
+        // initialize to default in case the app does not call initialize()
+        initialize(KEY_SIZE_DEFAULT, null);
+    }
+
+    // initialize the generator. See JCA doc
+    @Override
+    public void initialize(int keySize, SecureRandom random) {
+
+        checkKeySize(keySize);
+        this.params = NamedCurve.getECParameterSpec(keySize);
+        if (params == null) {
+            throw new InvalidParameterException(
+                "No EC parameters available for key size " + keySize + " bits");
+        }
+        this.random = random;
+    }
+
+    // second initialize method. See JCA doc
+    @Override
+    public void initialize(AlgorithmParameterSpec params, SecureRandom random)
+            throws InvalidAlgorithmParameterException {
+
+        if (params instanceof ECParameterSpec) {
+            this.params = ECParameters.getNamedCurve((ECParameterSpec)params);
+            if (this.params == null) {
+                throw new InvalidAlgorithmParameterException(
+                    "Unsupported curve: " + params);
+            }
+        } else if (params instanceof ECGenParameterSpec) {
+            String name = ((ECGenParameterSpec)params).getName();
+            this.params = NamedCurve.getECParameterSpec(name);
+            if (this.params == null) {
+                throw new InvalidAlgorithmParameterException(
+                    "Unknown curve name: " + name);
+            }
+        } else {
+            throw new InvalidAlgorithmParameterException(
+                "ECParameterSpec or ECGenParameterSpec required for EC");
+        }
+        this.keySize =
+            ((ECParameterSpec)this.params).getCurve().getField().getFieldSize();
+        this.random = random;
+    }
+
+    // generate the keypair. See JCA doc
+    @Override
+    public KeyPair generateKeyPair() {
+
+        byte[] encodedParams =
+            ECParameters.encodeParameters((ECParameterSpec)params);
+
+        // seed is twice the key size (in bytes)
+        byte[] seed = new byte[2 * ((keySize + 7) >> 3)];
+        if (random == null) {
+            random = JCAUtil.getSecureRandom();
+        }
+        random.nextBytes(seed);
+
+        long[] handles = generateECKeyPair(keySize, encodedParams, seed);
+
+        // The 'params' object supplied above is equivalent to the native one
+        // so there is no need to fetch it.
+
+        // handles[0] points to the native private key
+        BigInteger s = new BigInteger(1, getEncodedBytes(handles[0]));
+
+        try {
+            PrivateKey privateKey =
+                new ECPrivateKeyImpl(s, (ECParameterSpec)params);
+
+            // handles[1] points to the native public key
+            ECPoint w = ECParameters.decodePoint(getEncodedBytes(handles[1]),
+                ((ECParameterSpec)params).getCurve());
+            PublicKey publicKey =
+                new ECPublicKeyImpl(w, (ECParameterSpec)params);
+
+            return new KeyPair(publicKey, privateKey);
+
+        } catch (Exception e) {
+            throw new ProviderException(e);
+        }
+    }
+
+    private void checkKeySize(int keySize) throws InvalidParameterException {
+        if (keySize < KEY_SIZE_MIN) {
+            throw new InvalidParameterException
+                ("Key size must be at least " + KEY_SIZE_MIN + " bits");
+        }
+        if (keySize > KEY_SIZE_MAX) {
+            throw new InvalidParameterException
+                ("Key size must be at most " + KEY_SIZE_MAX + " bits");
+        }
+        this.keySize = keySize;
+    }
+
+    /*
+     * Generates the keypair and returns a 2-element array of handles.
+     * The first handle points to the private key, the second to the public key.
+     */
+    private static native long[] generateECKeyPair(int keySize,
+        byte[] encodedParams, byte[] seed);
+
+    /*
+     * Extracts the encoded key data using the supplied handle.
+     */
+    private static native byte[] getEncodedBytes(long handle);
+}