jdk/src/java.base/share/classes/com/sun/crypto/provider/DHParameterGenerator.java
--- /dev/null Thu Jan 01 00:00:00 1970 +0000
+++ b/jdk/src/java.base/share/classes/com/sun/crypto/provider/DHParameterGenerator.java Sun Aug 17 15:54:13 2014 +0100
@@ -0,0 +1,174 @@
+/*
+ * Copyright (c) 1997, 2013, 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 com.sun.crypto.provider;
+
+import java.security.*;
+import java.security.spec.*;
+import javax.crypto.spec.DHParameterSpec;
+import javax.crypto.spec.DHGenParameterSpec;
+
+/*
+ * This class generates parameters for the Diffie-Hellman algorithm.
+ * The parameters are a prime, a base, and optionally the length in bits of
+ * the private value.
+ *
+ * <p>The Diffie-Hellman parameter generation accepts the size in bits of the
+ * prime modulus and the size in bits of the random exponent as input.
+ * The size of the prime modulus defaults to 1024 bits.
+ *
+ * @author Jan Luehe
+ *
+ *
+ * @see java.security.AlgorithmParameters
+ * @see java.security.spec.AlgorithmParameterSpec
+ * @see DHParameters
+ */
+public final class DHParameterGenerator
+extends AlgorithmParameterGeneratorSpi {
+
+ // The size in bits of the prime modulus
+ private int primeSize = 1024;
+
+ // The size in bits of the random exponent (private value)
+ private int exponentSize = 0;
+
+ // The source of randomness
+ private SecureRandom random = null;
+
+ private static void checkKeySize(int keysize)
+ throws InvalidAlgorithmParameterException {
+ if ((keysize != 2048) &&
+ ((keysize < 512) || (keysize > 1024) || (keysize % 64 != 0))) {
+ throw new InvalidAlgorithmParameterException(
+ "Keysize must be multiple of 64 ranging from "
+ + "512 to 1024 (inclusive), or 2048");
+ }
+ }
+
+ /**
+ * Initializes this parameter generator for a certain keysize
+ * and source of randomness.
+ * The keysize is specified as the size in bits of the prime modulus.
+ *
+ * @param keysize the keysize (size of prime modulus) in bits
+ * @param random the source of randomness
+ */
+ protected void engineInit(int keysize, SecureRandom random) {
+ // Re-uses DSA parameters and thus have the same range
+ try {
+ checkKeySize(keysize);
+ } catch (InvalidAlgorithmParameterException ex) {
+ throw new InvalidParameterException(ex.getMessage());
+ }
+ this.primeSize = keysize;
+ this.random = random;
+ }
+
+ /**
+ * Initializes this parameter generator with a set of parameter
+ * generation values, which specify the size of the prime modulus and
+ * the size of the random exponent, both in bits.
+ *
+ * @param params the set of parameter generation values
+ * @param random the source of randomness
+ *
+ * @exception InvalidAlgorithmParameterException if the given parameter
+ * generation values are inappropriate for this parameter generator
+ */
+ protected void engineInit(AlgorithmParameterSpec genParamSpec,
+ SecureRandom random)
+ throws InvalidAlgorithmParameterException {
+ if (!(genParamSpec instanceof DHGenParameterSpec)) {
+ throw new InvalidAlgorithmParameterException
+ ("Inappropriate parameter type");
+ }
+
+ DHGenParameterSpec dhParamSpec = (DHGenParameterSpec)genParamSpec;
+
+ primeSize = dhParamSpec.getPrimeSize();
+
+ // Re-uses DSA parameters and thus have the same range
+ checkKeySize(primeSize);
+
+ exponentSize = dhParamSpec.getExponentSize();
+ if (exponentSize <= 0) {
+ throw new InvalidAlgorithmParameterException
+ ("Exponent size must be greater than zero");
+ }
+
+ // Require exponentSize < primeSize
+ if (exponentSize >= primeSize) {
+ throw new InvalidAlgorithmParameterException
+ ("Exponent size must be less than modulus size");
+ }
+ }
+
+ /**
+ * Generates the parameters.
+ *
+ * @return the new AlgorithmParameters object
+ */
+ protected AlgorithmParameters engineGenerateParameters() {
+ AlgorithmParameters algParams = null;
+
+ if (this.exponentSize == 0) {
+ this.exponentSize = this.primeSize - 1;
+ }
+
+ if (this.random == null)
+ this.random = SunJCE.getRandom();
+
+ try {
+ AlgorithmParameterGenerator paramGen;
+ DSAParameterSpec dsaParamSpec;
+
+ paramGen = AlgorithmParameterGenerator.getInstance("DSA");
+ paramGen.init(this.primeSize, random);
+ algParams = paramGen.generateParameters();
+ dsaParamSpec = algParams.getParameterSpec(DSAParameterSpec.class);
+
+ DHParameterSpec dhParamSpec;
+ if (this.exponentSize > 0) {
+ dhParamSpec = new DHParameterSpec(dsaParamSpec.getP(),
+ dsaParamSpec.getG(),
+ this.exponentSize);
+ } else {
+ dhParamSpec = new DHParameterSpec(dsaParamSpec.getP(),
+ dsaParamSpec.getG());
+ }
+ algParams = AlgorithmParameters.getInstance("DH",
+ SunJCE.getInstance());
+ algParams.init(dhParamSpec);
+ } catch (InvalidParameterSpecException e) {
+ // this should never happen
+ throw new RuntimeException(e.getMessage());
+ } catch (NoSuchAlgorithmException e) {
+ // this should never happen, because we provide it
+ throw new RuntimeException(e.getMessage());
+ }
+ return algParams;
+ }
+}