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 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
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 * published by the Free Software Foundation.  Oracle designates this
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 * 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).
 *
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package sun.security.ec.ed;

import java.io.IOException;
import java.security.AlgorithmParametersSpi;
import java.security.spec.AlgorithmParameterSpec;
import java.security.spec.ECParameterSpec;
import java.security.spec.EdDSAParameterSpec;
import java.security.spec.InvalidParameterSpecException;

This AlgorithmParametersSpi only supports NamedParameterSpec.
EdDSAParameterSpec is not support because there is not ASN.1 format
/**
 * This AlgorithmParametersSpi only supports NamedParameterSpec.
 * EdDSAParameterSpec is not support because there is not ASN.1 format
 */

public class EdDSAAlgorithmParameters extends AlgorithmParametersSpi {

    EdDSAParameterSpec edspec;

    // If no curve is provide, wait engineInit() to provide one.
    public EdDSAAlgorithmParameters() {
    }

    
NamedParameterSpec can only be used if curve was not specified
as part of getInstance(EdDSA).  If the curve was used, engineInit will
throws an exception for being already initialized.
EdDSAParameterSpec is not support because there is not ASN.1 format
Params:
paramSpec – NamedParameterSpec curve.
Throws:
InvalidParameterSpecException – /**
     * NamedParameterSpec can only be used if curve was not specified
     * as part of getInstance(EdDSA).  If the curve was used, engineInit will
     * throws an exception for being already initialized.
     * EdDSAParameterSpec is not support because there is not ASN.1 format
     *
     * @param paramSpec NamedParameterSpec curve.
     *
     * @throws InvalidParameterSpecException
     */
    @Override
    protected void engineInit(AlgorithmParameterSpec paramSpec)
            throws InvalidParameterSpecException {
        if (paramSpec instanceof EdDSAParameterSpec) {
            edspec = (EdDSAParameterSpec)paramSpec;
            return;
        }
        throw new InvalidParameterSpecException(
                "Unknown AlgorithmParameterSpec");
    }

    @Override
    protected void engineInit(byte[] params) throws IOException {
        throw new IOException(
                "EdDSA does not support parameters as a byte array.");
    }

    @Override
    protected void engineInit(byte[] params, String format) throws IOException {
        engineInit(params);
    }

    @Override
    protected <T extends AlgorithmParameterSpec> T engineGetParameterSpec(
            Class<T> paramSpec) throws InvalidParameterSpecException {

        if (paramSpec.isAssignableFrom(ECParameterSpec.class)) {
            return paramSpec.cast(edspec);
        }
        throw new InvalidParameterSpecException(
                "Only EDDSAParameterSpec supported.");
    }

    @Override
    protected byte[] engineGetEncoded() throws IOException {
        throw new IOException(
                "EdDSA does not support parameters as a byte array.");
    }

    @Override
    protected byte[] engineGetEncoded(String format) throws IOException {
        throw new IOException(
                "EdDSA does not support parameters as a byte array.");
    }

    @Override
    protected String engineToString() {
        return edspec.toString();
    }
}