obtained gcc-4.6.4.tar.bz2 from upstream website;upstream

verified gcc-4.6.4.tar.bz2.sig;
imported gcc-4.6.4 source tree from verified upstream tarball.

downloading a git-generated archive based on the 'upstream' tag
should provide you with a source tree that is binary identical
to the one extracted from the above tarball.

if you have obtained the source via the command 'git clone',
however, do note that line-endings of files in your working
directory might differ from line-endings of the respective
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4 files changed, 686 insertions, 0 deletions

diff --git a/libjava/classpath/gnu/javax/crypto/jce/sig/DHKeyFactory.java b/libjava/classpath/gnu/javax/crypto/jce/sig/DHKeyFactory.java
new file mode 100644
index 000000000..98b265dd3
--- /dev/null
+++ b/libjava/classpath/gnu/javax/crypto/jce/sig/DHKeyFactory.java
@@ -0,0 +1,219 @@
+/* DHKeyFactory.java -- DH key-factory JCE Adapter
+   Copyright (C) 2006 Free Software Foundation, Inc.
+
+This file is part of GNU Classpath.
+
+GNU Classpath is free software; you can redistribute it and/or modify
+it under the terms of the GNU General Public License as published by
+the Free Software Foundation; either version 2, or (at your option)
+any later version.
+
+GNU Classpath 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 for more details.
+
+You should have received a copy of the GNU General Public License
+along with GNU Classpath; see the file COPYING.  If not, write to the
+Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
+02110-1301 USA.
+
+Linking this library statically or dynamically with other modules is
+making a combined work based on this library.  Thus, the terms and
+conditions of the GNU General Public License cover the whole
+combination.
+
+As a special exception, the copyright holders of this library give you
+permission to link this library with independent modules to produce an
+executable, regardless of the license terms of these independent
+modules, and to copy and distribute the resulting executable under
+terms of your choice, provided that you also meet, for each linked
+independent module, the terms and conditions of the license of that
+module.  An independent module is a module which is not derived from
+or based on this library.  If you modify this library, you may extend
+this exception to your version of the library, but you are not
+obligated to do so.  If you do not wish to do so, delete this
+exception statement from your version. */
+
+
+package gnu.javax.crypto.jce.sig;
+
+import gnu.java.security.Registry;
+import gnu.javax.crypto.key.dh.DHKeyPairPKCS8Codec;
+import gnu.javax.crypto.key.dh.DHKeyPairX509Codec;
+import gnu.javax.crypto.key.dh.GnuDHPrivateKey;
+import gnu.javax.crypto.key.dh.GnuDHPublicKey;
+
+import java.math.BigInteger;
+import java.security.InvalidKeyException;
+import java.security.Key;
+import java.security.KeyFactorySpi;
+import java.security.PrivateKey;
+import java.security.PublicKey;
+import java.security.spec.InvalidKeySpecException;
+import java.security.spec.KeySpec;
+import java.security.spec.PKCS8EncodedKeySpec;
+import java.security.spec.X509EncodedKeySpec;
+
+import javax.crypto.interfaces.DHPrivateKey;
+import javax.crypto.interfaces.DHPublicKey;
+import javax.crypto.spec.DHPrivateKeySpec;
+import javax.crypto.spec.DHPublicKeySpec;
+
+/**
+ * Implementation of a JCE Adapter for DH a key-factory.
+ */
+public class DHKeyFactory
+    extends KeyFactorySpi
+{
+  // implicit 0-arguments constructor
+
+  protected PublicKey engineGeneratePublic(KeySpec keySpec)
+      throws InvalidKeySpecException
+  {
+    if (keySpec instanceof DHPublicKeySpec)
+      {
+        DHPublicKeySpec spec = (DHPublicKeySpec) keySpec;
+        BigInteger p = spec.getP();
+        BigInteger g = spec.getG();
+        BigInteger y = spec.getY();
+        return new GnuDHPublicKey(Registry.X509_ENCODING_ID, null, p, g, y);
+      }
+    if (keySpec instanceof X509EncodedKeySpec)
+      {
+        X509EncodedKeySpec spec = (X509EncodedKeySpec) keySpec;
+        byte[] encoded = spec.getEncoded();
+        PublicKey result;
+        try
+          {
+            result = new DHKeyPairX509Codec().decodePublicKey(encoded);
+            return result;
+          }
+        catch (RuntimeException x)
+          {
+            InvalidKeySpecException y = new InvalidKeySpecException();
+            y.initCause(x);
+            throw y;
+          }
+      }
+    throw new InvalidKeySpecException("Unsupported (public) key specification");
+  }
+
+  protected PrivateKey engineGeneratePrivate(KeySpec keySpec)
+      throws InvalidKeySpecException
+  {
+    if (keySpec instanceof DHPrivateKeySpec)
+      {
+        DHPrivateKeySpec spec = (DHPrivateKeySpec) keySpec;
+        BigInteger p = spec.getP();
+        BigInteger g = spec.getG();
+        BigInteger x = spec.getX();
+        return new GnuDHPrivateKey(Registry.PKCS8_ENCODING_ID, null, p, g, x);
+      }
+    if (keySpec instanceof PKCS8EncodedKeySpec)
+      {
+        PKCS8EncodedKeySpec spec = (PKCS8EncodedKeySpec) keySpec;
+        byte[] encoded = spec.getEncoded();
+        PrivateKey result;
+        try
+          {
+            result = new DHKeyPairPKCS8Codec().decodePrivateKey(encoded);
+            return result;
+          }
+        catch (RuntimeException x)
+          {
+            InvalidKeySpecException y = new InvalidKeySpecException();
+            y.initCause(x);
+            throw y;
+          }
+      }
+    throw new InvalidKeySpecException("Unsupported (private) key specification");
+  }
+
+  protected KeySpec engineGetKeySpec(Key key, Class keySpec)
+      throws InvalidKeySpecException
+  {
+    if (key instanceof DHPublicKey)
+      {
+        if (keySpec.isAssignableFrom(DHPublicKeySpec.class))
+          {
+            DHPublicKey dssKey = (DHPublicKey) key;
+            BigInteger p = dssKey.getParams().getP();
+            BigInteger g = dssKey.getParams().getG();
+            BigInteger y = dssKey.getY();
+            return new DHPublicKeySpec(y, p, g);
+          }
+        if (keySpec.isAssignableFrom(X509EncodedKeySpec.class))
+          {
+            if (key instanceof GnuDHPublicKey)
+              {
+                GnuDHPublicKey dhKey = (GnuDHPublicKey) key;
+                byte[] encoded = dhKey.getEncoded(Registry.X509_ENCODING_ID);
+                return new X509EncodedKeySpec(encoded);
+              }
+            if (Registry.X509_ENCODING_SORT_NAME.equalsIgnoreCase(key.getFormat()))
+              {
+                byte[] encoded = key.getEncoded();
+                return new X509EncodedKeySpec(encoded);
+              }
+            throw new InvalidKeySpecException(
+                "Wrong key type or unsupported (public) key specification");
+          }
+        throw new InvalidKeySpecException("Unsupported (public) key specification");
+      }
+    if (key instanceof DHPrivateKey)
+      {
+        if (keySpec.isAssignableFrom(DHPrivateKeySpec.class))
+          {
+            DHPrivateKey dhKey = (DHPrivateKey) key;
+            BigInteger p = dhKey.getParams().getP();
+            BigInteger g = dhKey.getParams().getG();
+            BigInteger x = dhKey.getX();
+            return new DHPrivateKeySpec(x, p, g);
+          }
+        if (keySpec.isAssignableFrom(PKCS8EncodedKeySpec.class))
+          {
+            if (key instanceof GnuDHPrivateKey)
+              {
+                GnuDHPrivateKey dhKey = (GnuDHPrivateKey) key;
+                byte[] encoded = dhKey.getEncoded(Registry.PKCS8_ENCODING_ID);
+                return new PKCS8EncodedKeySpec(encoded);
+              }
+            if (Registry.PKCS8_ENCODING_SHORT_NAME.equalsIgnoreCase(key.getFormat()))
+              {
+                byte[] encoded = key.getEncoded();
+                return new PKCS8EncodedKeySpec(encoded);
+              }
+            throw new InvalidKeySpecException(
+                "Wrong key type or unsupported (private) key specification");
+          }
+        throw new InvalidKeySpecException(
+            "Unsupported (private) key specification");
+      }
+    throw new InvalidKeySpecException(
+        "Wrong key type or unsupported key specification");
+  }
+
+  protected Key engineTranslateKey(Key key) throws InvalidKeyException
+  {
+    if ((key instanceof GnuDHPublicKey) || (key instanceof GnuDHPrivateKey))
+      return key;
+    if (key instanceof DHPublicKey)
+      {
+        DHPublicKey dsaKey = (DHPublicKey) key;
+        BigInteger p = dsaKey.getParams().getP();
+        BigInteger g = dsaKey.getParams().getG();
+        BigInteger y = dsaKey.getY();
+        return new GnuDHPublicKey(Registry.X509_ENCODING_ID, null, p, g, y);
+      }
+    if (key instanceof DHPrivateKey)
+      {
+        DHPrivateKey dsaKey = (DHPrivateKey) key;
+        BigInteger p = dsaKey.getParams().getP();
+        BigInteger g = dsaKey.getParams().getG();
+        BigInteger x = dsaKey.getX();
+        return new GnuDHPrivateKey(Registry.PKCS8_ENCODING_ID, null, p, g, x);
+      }
+    throw new InvalidKeyException("Wrong key type");
+  }
+}
diff --git a/libjava/classpath/gnu/javax/crypto/jce/sig/DHKeyPairGeneratorSpi.java b/libjava/classpath/gnu/javax/crypto/jce/sig/DHKeyPairGeneratorSpi.java
new file mode 100644
index 000000000..e26f07124
--- /dev/null
+++ b/libjava/classpath/gnu/javax/crypto/jce/sig/DHKeyPairGeneratorSpi.java
@@ -0,0 +1,93 @@
+/* DHKeyPairGeneratorSpi.java -- DH key-pair generator JCE Adapter
+   Copyright (C) 2006 Free Software Foundation, Inc.
+
+This file is part of GNU Classpath.
+
+GNU Classpath is free software; you can redistribute it and/or modify
+it under the terms of the GNU General Public License as published by
+the Free Software Foundation; either version 2, or (at your option)
+any later version.
+
+GNU Classpath 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 for more details.
+
+You should have received a copy of the GNU General Public License
+along with GNU Classpath; see the file COPYING.  If not, write to the
+Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
+02110-1301 USA.
+
+Linking this library statically or dynamically with other modules is
+making a combined work based on this library.  Thus, the terms and
+conditions of the GNU General Public License cover the whole
+combination.
+
+As a special exception, the copyright holders of this library give you
+permission to link this library with independent modules to produce an
+executable, regardless of the license terms of these independent
+modules, and to copy and distribute the resulting executable under
+terms of your choice, provided that you also meet, for each linked
+independent module, the terms and conditions of the license of that
+module.  An independent module is a module which is not derived from
+or based on this library.  If you modify this library, you may extend
+this exception to your version of the library, but you are not
+obligated to do so.  If you do not wish to do so, delete this
+exception statement from your version. */
+
+
+package gnu.javax.crypto.jce.sig;
+
+import java.security.InvalidAlgorithmParameterException;
+import java.security.SecureRandom;
+import java.security.spec.AlgorithmParameterSpec;
+import java.util.HashMap;
+
+import javax.crypto.spec.DHGenParameterSpec;
+import javax.crypto.spec.DHParameterSpec;
+
+import gnu.java.security.Registry;
+import gnu.java.security.jce.sig.KeyPairGeneratorAdapter;
+import gnu.javax.crypto.key.dh.GnuDHKeyPairGenerator;
+
+public class DHKeyPairGeneratorSpi
+    extends KeyPairGeneratorAdapter
+{
+  public DHKeyPairGeneratorSpi()
+  {
+    super(Registry.DH_KPG);
+  }
+
+  public void initialize(int keysize, SecureRandom random)
+  {
+    HashMap attributes = new HashMap();
+    attributes.put(GnuDHKeyPairGenerator.PRIME_SIZE, Integer.valueOf(keysize));
+    if (random != null)
+      attributes.put(GnuDHKeyPairGenerator.SOURCE_OF_RANDOMNESS, random);
+
+    attributes.put(GnuDHKeyPairGenerator.PREFERRED_ENCODING_FORMAT,
+                   Integer.valueOf(Registry.ASN1_ENCODING_ID));
+    adaptee.setup(attributes);
+  }
+
+  public void initialize(AlgorithmParameterSpec params, SecureRandom random)
+      throws InvalidAlgorithmParameterException
+  {
+    HashMap attributes = new HashMap();
+    if (params != null)
+      {
+        if (! (params instanceof DHGenParameterSpec) &&
+            ! (params instanceof DHParameterSpec))
+          throw new InvalidAlgorithmParameterException("params");
+
+        attributes.put(GnuDHKeyPairGenerator.DH_PARAMETERS, params);
+      }
+
+    if (random != null)
+      attributes.put(GnuDHKeyPairGenerator.SOURCE_OF_RANDOMNESS, random);
+
+    attributes.put(GnuDHKeyPairGenerator.PREFERRED_ENCODING_FORMAT,
+                   Integer.valueOf(Registry.ASN1_ENCODING_ID));
+    adaptee.setup(attributes);
+  }
+}
diff --git a/libjava/classpath/gnu/javax/crypto/jce/sig/DHParameters.java b/libjava/classpath/gnu/javax/crypto/jce/sig/DHParameters.java
new file mode 100644
index 000000000..cc656d2c8
--- /dev/null
+++ b/libjava/classpath/gnu/javax/crypto/jce/sig/DHParameters.java
@@ -0,0 +1,222 @@
+/* DHParameters.java -- DH parameters DAO
+   Copyright (C) 2006 Free Software Foundation, Inc.
+
+This file is part of GNU Classpath.
+
+GNU Classpath is free software; you can redistribute it and/or modify
+it under the terms of the GNU General Public License as published by
+the Free Software Foundation; either version 2, or (at your option)
+any later version.
+
+GNU Classpath 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 for more details.
+
+You should have received a copy of the GNU General Public License
+along with GNU Classpath; see the file COPYING.  If not, write to the
+Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
+02110-1301 USA.
+
+Linking this library statically or dynamically with other modules is
+making a combined work based on this library.  Thus, the terms and
+conditions of the GNU General Public License cover the whole
+combination.
+
+As a special exception, the copyright holders of this library give you
+permission to link this library with independent modules to produce an
+executable, regardless of the license terms of these independent
+modules, and to copy and distribute the resulting executable under
+terms of your choice, provided that you also meet, for each linked
+independent module, the terms and conditions of the license of that
+module.  An independent module is a module which is not derived from
+or based on this library.  If you modify this library, you may extend
+this exception to your version of the library, but you are not
+obligated to do so.  If you do not wish to do so, delete this
+exception statement from your version. */
+
+
+package gnu.javax.crypto.jce.sig;
+
+import gnu.java.lang.CPStringBuilder;
+
+import gnu.java.security.Registry;
+import gnu.java.security.der.DER;
+import gnu.java.security.der.DERReader;
+import gnu.java.security.der.DERValue;
+import gnu.java.security.der.DERWriter;
+import gnu.java.security.util.DerUtil;
+
+import java.io.ByteArrayOutputStream;
+import java.io.IOException;
+import java.math.BigInteger;
+import java.security.AlgorithmParametersSpi;
+import java.security.spec.AlgorithmParameterSpec;
+import java.security.spec.InvalidParameterSpecException;
+import java.util.ArrayList;
+
+import javax.crypto.spec.DHGenParameterSpec;
+import javax.crypto.spec.DHParameterSpec;
+
+/**
+ * A JCE-specific Data Access Object (DAO) for DH parameters.
+ */
+public class DHParameters
+    extends AlgorithmParametersSpi
+{
+  /** The prime public modulus. */
+  private BigInteger p;
+
+  /** The generator. */
+  private BigInteger g;
+
+  /** A prime factor of p-1. */
+  private BigInteger q;
+
+  /** The (private) random exponent's size (in bits). */
+  private int l;
+
+  // default 0-arguments constructor
+
+  protected void engineInit(AlgorithmParameterSpec spec)
+      throws InvalidParameterSpecException
+  {
+    if (! (spec instanceof DHParameterSpec))
+      throw new InvalidParameterSpecException("Wrong AlgorithmParameterSpec type: "
+                                              + spec.getClass().getName());
+    DHParameterSpec dhSpec = (DHParameterSpec) spec;
+    p = dhSpec.getP();
+    g = dhSpec.getG();
+    l = dhSpec.getL();
+  }
+
+  /**
+   * Decodes the set of DH parameters as per RFC-2459; i.e. the DER-encoded
+   * form of the following ASN.1 construct:
+   *
+   * <pre>
+   *   DhParams ::= SEQUENCE {
+   *     p  INTEGER, -- odd prime, p=jq +1
+   *     g  INTEGER, -- generator, g
+   *     q  INTEGER  -- factor of p-1
+   *   }
+   * </pre>
+   */
+  protected void engineInit(byte[] params) throws IOException
+  {
+    DERReader der = new DERReader(params);
+
+    DERValue derParams = der.read();
+    DerUtil.checkIsConstructed(derParams, "Wrong DH Parameters field");
+
+    DERValue val = der.read();
+    DerUtil.checkIsBigInteger(val, "Wrong P field");
+    p = (BigInteger) val.getValue();
+    val = der.read();
+    DerUtil.checkIsBigInteger(val, "Wrong G field");
+    g = (BigInteger) val.getValue();
+    val = der.read();
+    DerUtil.checkIsBigInteger(val, "Wrong Q field");
+    q = (BigInteger) val.getValue();
+    l = q.bitLength();
+  }
+
+  protected void engineInit(byte[] params, String format) throws IOException
+  {
+    if (format != null)
+      {
+        format = format.trim();
+        if (format.length() == 0)
+          throw new IOException("Format MUST NOT be an empty string");
+
+        if (! format.equalsIgnoreCase(Registry.ASN1_ENCODING_SHORT_NAME))
+          throw new IOException("Unknown or unsupported format: " + format);
+      }
+
+    engineInit(params);
+  }
+
+  protected AlgorithmParameterSpec engineGetParameterSpec(Class paramSpec)
+      throws InvalidParameterSpecException
+  {
+    if (paramSpec.isAssignableFrom(DHParameterSpec.class))
+      return new DHParameterSpec(p, g, l);
+
+    if (paramSpec.isAssignableFrom(DHGenParameterSpec.class))
+      return new DHGenParameterSpec(p.bitLength(), l);
+
+    throw new InvalidParameterSpecException("Wrong AlgorithmParameterSpec type: "
+                                            + paramSpec.getName());
+  }
+
+  /**
+   * Encodes the set of DH parameters as per RFC-2459; i.e. as the DER-encoded
+   * form of the following ASN.1 construct:
+   *
+   * <pre>
+   *   DhParams ::= SEQUENCE {
+   *     p  INTEGER, -- odd prime, p=jq +1
+   *     g  INTEGER, -- generator, g
+   *     q  INTEGER  -- factor of p-1
+   *   }
+   * </pre>
+   */
+  protected byte[] engineGetEncoded() throws IOException
+  {
+    DERValue derP = new DERValue(DER.INTEGER, p);
+    DERValue derG = new DERValue(DER.INTEGER, g);
+    DERValue derQ = new DERValue(DER.INTEGER, q);
+
+    ArrayList params = new ArrayList(3);
+    params.add(derP);
+    params.add(derG);
+    params.add(derQ);
+    DERValue derParams = new DERValue(DER.CONSTRUCTED | DER.SEQUENCE, params);
+
+    ByteArrayOutputStream baos = new ByteArrayOutputStream();
+    DERWriter.write(baos, derParams);
+    byte[] result = baos.toByteArray();
+
+    return result;
+  }
+
+  protected byte[] engineGetEncoded(String format) throws IOException
+  {
+    if (format != null)
+      {
+        format = format.trim();
+        if (format.length() == 0)
+          throw new IOException("Format MUST NOT be an empty string");
+
+        if (! format.equalsIgnoreCase(Registry.ASN1_ENCODING_SHORT_NAME))
+          throw new IOException("Unknown or unsupported format: " + format);
+      }
+
+    return engineGetEncoded();
+  }
+
+  protected String engineToString()
+  {
+    CPStringBuilder sb = new CPStringBuilder("p=");
+    if (p == null)
+      sb.append("???");
+    else
+      sb.append("0x").append(p.toString(16));
+
+    sb.append(", g=");
+    if (g == null)
+      sb.append("???");
+    else
+      sb.append("0x").append(g.toString(16));
+
+    sb.append(", q=");
+    if (q == null)
+      sb.append("???");
+    else
+      sb.append("0x").append(q.toString(16));
+
+    sb.append(", l=").append(l);
+
+    return sb.toString();
+  }
+}
diff --git a/libjava/classpath/gnu/javax/crypto/jce/sig/DHParametersGenerator.java b/libjava/classpath/gnu/javax/crypto/jce/sig/DHParametersGenerator.java
new file mode 100644
index 000000000..3687ac3ca
--- /dev/null
+++ b/libjava/classpath/gnu/javax/crypto/jce/sig/DHParametersGenerator.java
@@ -0,0 +1,152 @@
+/* DHParametersGenerator.java -- JCE Adapter for a generator of DH parameters
+   Copyright (C) 2006 Free Software Foundation, Inc.
+
+This file is part of GNU Classpath.
+
+GNU Classpath is free software; you can redistribute it and/or modify
+it under the terms of the GNU General Public License as published by
+the Free Software Foundation; either version 2, or (at your option)
+any later version.
+
+GNU Classpath 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 for more details.
+
+You should have received a copy of the GNU General Public License
+along with GNU Classpath; see the file COPYING.  If not, write to the
+Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
+02110-1301 USA.
+
+Linking this library statically or dynamically with other modules is
+making a combined work based on this library.  Thus, the terms and
+conditions of the GNU General Public License cover the whole
+combination.
+
+As a special exception, the copyright holders of this library give you
+permission to link this library with independent modules to produce an
+executable, regardless of the license terms of these independent
+modules, and to copy and distribute the resulting executable under
+terms of your choice, provided that you also meet, for each linked
+independent module, the terms and conditions of the license of that
+module.  An independent module is a module which is not derived from
+or based on this library.  If you modify this library, you may extend
+this exception to your version of the library, but you are not
+obligated to do so.  If you do not wish to do so, delete this
+exception statement from your version. */
+
+
+package gnu.javax.crypto.jce.sig;
+
+import gnu.java.security.Registry;
+import gnu.javax.crypto.jce.GnuCrypto;
+import gnu.javax.crypto.key.dh.GnuDHKeyPairGenerator;
+import gnu.javax.crypto.key.dh.RFC2631;
+
+import java.math.BigInteger;
+import java.security.AlgorithmParameterGeneratorSpi;
+import java.security.AlgorithmParameters;
+import java.security.InvalidAlgorithmParameterException;
+import java.security.InvalidParameterException;
+import java.security.NoSuchAlgorithmException;
+import java.security.Provider;
+import java.security.SecureRandom;
+import java.security.spec.AlgorithmParameterSpec;
+import java.security.spec.InvalidParameterSpecException;
+
+import javax.crypto.spec.DHGenParameterSpec;
+import javax.crypto.spec.DHParameterSpec;
+
+/**
+ * A JCE Adapter for a generator of DH parameters.
+ */
+public class DHParametersGenerator
+    extends AlgorithmParameterGeneratorSpi
+{
+  private static final Provider GNU_CRYPTO = new GnuCrypto();
+
+  /** Size of the prime (public) modulus in bits. */
+  private int modulusSize = -1;
+
+  /** Size of the prime (private) modulus in bits. */
+  private int exponentSize = -1;
+
+  /** User specified source of randomness. */
+  private SecureRandom rnd;
+
+  /** Our concrete DH parameters generator. */
+  private RFC2631 rfc2631;
+
+
+  protected void engineInit(int size, SecureRandom random)
+  {
+    if ((size % 256) != 0 || size < GnuDHKeyPairGenerator.DEFAULT_PRIME_SIZE)
+      throw new InvalidParameterException("Prime modulus (p) size (in bits) "
+                                          + "MUST be a multiple of 256, and "
+                                          + "greater than or equal to 1024");
+    this.modulusSize = size;
+    this.rnd = random;
+  }
+
+  protected void engineInit(AlgorithmParameterSpec spec, SecureRandom random)
+      throws InvalidAlgorithmParameterException
+  {
+    if (spec instanceof DHParameterSpec)
+      {
+        DHParameterSpec dhSpec = (DHParameterSpec) spec;
+        BigInteger p = dhSpec.getP();
+        int size = p.bitLength();
+        this.engineInit(size, random);
+      }
+    else if (spec instanceof DHGenParameterSpec)
+      {
+        DHGenParameterSpec dhSpec = (DHGenParameterSpec) spec;
+        int size = dhSpec.getPrimeSize();
+        this.engineInit(size, random);
+        exponentSize = dhSpec.getExponentSize();
+
+        if ((exponentSize % 8) != 0
+            || exponentSize < GnuDHKeyPairGenerator.DEFAULT_EXPONENT_SIZE)
+          throw new InvalidParameterException("Random exponent size (in bits) "
+                                              + "MUST be a multiple of 8, and "
+                                              + "greater than or equal to "
+                                              + GnuDHKeyPairGenerator.DEFAULT_EXPONENT_SIZE);
+        if (exponentSize > modulusSize)
+          throw new InvalidParameterException("Random exponent size (in bits) "
+                                              + "MUST be less than that of the "
+                                              + "public prime modulus (p)");
+      }
+
+    throw new InvalidAlgorithmParameterException("Wrong AlgorithmParameterSpec type: "
+                                                 + spec.getClass().getName());
+  }
+
+  protected AlgorithmParameters engineGenerateParameters()
+  {
+    if (modulusSize < 1)
+      modulusSize = GnuDHKeyPairGenerator.DEFAULT_PRIME_SIZE;
+
+    if (exponentSize < 1)
+      exponentSize = GnuDHKeyPairGenerator.DEFAULT_EXPONENT_SIZE;
+
+    rfc2631 = new RFC2631(exponentSize, modulusSize, rnd);
+    BigInteger[] params = rfc2631.generateParameters();
+    BigInteger p = params[RFC2631.DH_PARAMS_P];
+    BigInteger g = params[RFC2631.DH_PARAMS_G];
+    int l = params[RFC2631.DH_PARAMS_Q].bitLength();
+    DHParameterSpec spec = new DHParameterSpec(p, g, l);
+    AlgorithmParameters result = null;
+    try
+      {
+        result = AlgorithmParameters.getInstance(Registry.DH_KPG, GNU_CRYPTO);
+        result.init(spec);
+      }
+    catch (NoSuchAlgorithmException ignore)
+      {
+      }
+    catch (InvalidParameterSpecException ignore)
+      {
+      }
+    return result;
+  }
+}