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* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
*
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* 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.
*
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package sun.security.provider;
import java.util.*;
import java.io.*;
import java.math.BigInteger;
import java.security.AlgorithmParametersSpi;
import java.security.spec.AlgorithmParameterSpec;
import java.security.spec.DSAParameterSpec;
import java.security.spec.InvalidParameterSpecException;
import sun.security.util.Debug;
import sun.security.util.DerValue;
import sun.security.util.DerOutputStream;
/**
* This class implements the parameter set used by the
* Digital Signature Algorithm as specified in the FIPS 186
* standard.
*
* @author Jan Luehe
*
*
* @since 1.2
*/
public class DSAParameters extends AlgorithmParametersSpi {
// the prime (p)
protected BigInteger p;
// the sub-prime (q)
protected BigInteger q;
// the base (g)
protected BigInteger g;
protected void engineInit(AlgorithmParameterSpec paramSpec)
throws InvalidParameterSpecException {
if (!(paramSpec instanceof DSAParameterSpec)) {
throw new InvalidParameterSpecException
("Inappropriate parameter specification");
}
this.p = ((DSAParameterSpec)paramSpec).getP();
this.q = ((DSAParameterSpec)paramSpec).getQ();
this.g = ((DSAParameterSpec)paramSpec).getG();
}
protected void engineInit(byte[] params) throws IOException {
DerValue encodedParams = new DerValue(params);
if (encodedParams.tag != DerValue.tag_Sequence) {
throw new IOException("DSA params parsing error");
}
encodedParams.data.reset();
this.p = encodedParams.data.getBigInteger();
this.q = encodedParams.data.getBigInteger();
this.g = encodedParams.data.getBigInteger();
if (encodedParams.data.available() != 0) {
throw new IOException("encoded params have " +
encodedParams.data.available() +
" extra bytes");
}
}
protected void engineInit(byte[] params, String decodingMethod)
throws IOException {
engineInit(params);
}
protected <T extends AlgorithmParameterSpec>
T engineGetParameterSpec(Class<T> paramSpec)
throws InvalidParameterSpecException
{
try {
Class<?> dsaParamSpec = Class.forName
("java.security.spec.DSAParameterSpec");
if (dsaParamSpec.isAssignableFrom(paramSpec)) {
return (T)new DSAParameterSpec(this.p, this.q, this.g);
} else {
throw new InvalidParameterSpecException
("Inappropriate parameter Specification");
}
} catch (ClassNotFoundException e) {
throw new InvalidParameterSpecException
("Unsupported parameter specification: " + e.getMessage());
}
}
protected byte[] engineGetEncoded() throws IOException {
DerOutputStream out = new DerOutputStream();
DerOutputStream bytes = new DerOutputStream();
bytes.putInteger(p);
bytes.putInteger(q);
bytes.putInteger(g);
out.write(DerValue.tag_Sequence, bytes);
return out.toByteArray();
}
protected byte[] engineGetEncoded(String encodingMethod)
throws IOException {
return engineGetEncoded();
}
/*
* Returns a formatted string describing the parameters.
*/
protected String engineToString() {
return "\n\tp: " + Debug.toHexString(p)
+ "\n\tq: " + Debug.toHexString(q)
+ "\n\tg: " + Debug.toHexString(g)
+ "\n";
}
}