/*
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements. See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership. The ASF licenses this file
 * to you under the Apache License, Version 2.0 (the
 * "License"); you may not use this file except in compliance
 * with the License. You may obtain a copy of the License at
 *
 * http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing,
 * software distributed under the License is distributed on an
 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
 * KIND, either express or implied. See the License for the
 * specific language governing permissions and limitations
 * under the License.
 */

package org.apache.sshd.common.util.buffer.keys;

import java.math.BigInteger;
import java.security.GeneralSecurityException;
import java.security.interfaces.RSAPublicKey;
import java.security.spec.RSAPublicKeySpec;

import org.apache.sshd.common.config.keys.KeyUtils;
import org.apache.sshd.common.keyprovider.KeyPairProvider;
import org.apache.sshd.common.util.ValidateUtils;
import org.apache.sshd.common.util.buffer.Buffer;

/**
 * @author <a href="mailto:dev@mina.apache.org">Apache MINA SSHD Project</a>
 */
public class RSABufferPublicKeyParser extends AbstractBufferPublicKeyParser<RSAPublicKey> {
    public static final RSABufferPublicKeyParser INSTANCE = new RSABufferPublicKeyParser();

    public RSABufferPublicKeyParser() {
        super(RSAPublicKey.class, KeyPairProvider.SSH_RSA);
    }

    @Override
    public RSAPublicKey getRawPublicKey(String keyType, Buffer buffer) throws GeneralSecurityException {
        ValidateUtils.checkTrue(isKeyTypeSupported(keyType), "Unsupported key type: %s", keyType);
        BigInteger e = buffer.getMPInt();
        BigInteger n = buffer.getMPInt();
        return generatePublicKey(KeyUtils.RSA_ALGORITHM, new RSAPublicKeySpec(n, e));
    }
}