de.alpharogroup.crypto.key.reader.PublicKeyReader.java Source code

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/**
 * The MIT License
 *
 * Copyright (C) 2015 Asterios Raptis
 *
 * Permission is hereby granted, free of charge, to any person obtaining
 * a copy of this software and associated documentation files (the
 * "Software"), to deal in the Software without restriction, including
 * without limitation the rights to use, copy, modify, merge, publish,
 * distribute, sublicense, and/or sell copies of the Software, and to
 * permit persons to whom the Software is furnished to do so, subject to
 * the following conditions:
 *
 * The above copyright notice and this permission notice shall be
 * included in all copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
 * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
 * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
 * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
 * LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
 * OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
 * WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
 */
package de.alpharogroup.crypto.key.reader;

import java.io.File;
import java.io.IOException;
import java.nio.file.Files;
import java.security.KeyFactory;
import java.security.NoSuchAlgorithmException;
import java.security.NoSuchProviderException;
import java.security.PublicKey;
import java.security.spec.InvalidKeySpecException;
import java.security.spec.X509EncodedKeySpec;

import org.apache.commons.codec.binary.Base64;

import de.alpharogroup.crypto.algorithm.KeyPairGeneratorAlgorithm;
import de.alpharogroup.crypto.provider.SecurityProvider;
import lombok.experimental.UtilityClass;

/**
 * The class {@link PublicKeyReader} is a utility class for reading public keys.
 */
@UtilityClass
public class PublicKeyReader {

    /** The Constant END_PUBLIC_KEY_SUFFIX. */
    public static final String END_PUBLIC_KEY_SUFFIX = "-----END PUBLIC KEY-----";

    /** The Constant BEGIN_PUBLIC_KEY_PREFIX. */
    public static final String BEGIN_PUBLIC_KEY_PREFIX = "-----BEGIN PUBLIC KEY-----\n";

    /**
     * Read public key.
     *
     * @param file
     *            the file
     * @return the public key
     * @throws IOException
     *             Signals that an I/O exception has occurred.
     * @throws NoSuchAlgorithmException
     *             is thrown if instantiation of the cypher object fails.
     * @throws InvalidKeySpecException
     *             is thrown if generation of the SecretKey object fails.
     * @throws NoSuchProviderException
     *             is thrown if the specified provider is not registered in the security provider
     *             list.
     */
    public static PublicKey readPublicKey(final File file)
            throws IOException, NoSuchAlgorithmException, InvalidKeySpecException, NoSuchProviderException {
        final byte[] keyBytes = Files.readAllBytes(file.toPath());
        return readPublicKey(keyBytes, "BC");
    }

    /**
     * Read public key.
     *
     * @param publicKeyBytes
     *            the public key bytes
     * @param securityProvider
     *            the security provider
     * @return the public key
     * @throws NoSuchAlgorithmException
     *             is thrown if instantiation of the cypher object fails.
     * @throws InvalidKeySpecException
     *             is thrown if generation of the SecretKey object fails.
     * @throws NoSuchProviderException
     *             is thrown if the specified provider is not registered in the security provider
     *             list.
     */
    public static PublicKey readPublicKey(final byte[] publicKeyBytes, final SecurityProvider securityProvider)
            throws NoSuchAlgorithmException, InvalidKeySpecException, NoSuchProviderException {
        return readPublicKey(publicKeyBytes, securityProvider.name());
    }

    /**
     * Read public key.
     *
     * @param publicKeyBytes
     *            the public key bytes
     * @param provider
     *            the provider
     * @return the public key
     * @throws NoSuchAlgorithmException
     *             is thrown if instantiation of the cypher object fails.
     * @throws InvalidKeySpecException
     *             is thrown if generation of the SecretKey object fails.
     * @throws NoSuchProviderException
     *             is thrown if the specified provider is not registered in the security provider
     *             list.
     */
    public static PublicKey readPublicKey(final byte[] publicKeyBytes, final String provider)
            throws NoSuchAlgorithmException, InvalidKeySpecException, NoSuchProviderException {
        return readPublicKey(publicKeyBytes, provider, KeyPairGeneratorAlgorithm.RSA.getAlgorithm());
    }

    /**
     * Read public key.
     *
     * @param publicKeyBytes
     *            the public key bytes
     * @param provider
     *            the provider
     * @param algorithm
     *            the algorithm for the {@link KeyFactory}
     * @return the public key
     * @throws NoSuchAlgorithmException
     *             is thrown if instantiation of the cypher object fails.
     * @throws InvalidKeySpecException
     *             is thrown if generation of the SecretKey object fails.
     * @throws NoSuchProviderException
     *             is thrown if the specified provider is not registered in the security provider
     *             list.
     */
    public static PublicKey readPublicKey(final byte[] publicKeyBytes, final String provider,
            final String algorithm)
            throws NoSuchAlgorithmException, InvalidKeySpecException, NoSuchProviderException {
        final X509EncodedKeySpec keySpec = new X509EncodedKeySpec(publicKeyBytes);
        final KeyFactory keyFactory = KeyFactory.getInstance(algorithm);
        final PublicKey publicKey = keyFactory.generatePublic(keySpec);
        return publicKey;
    }

    /**
     * reads a public key from a file.
     *
     * @param file
     *            the file
     * @param securityProvider
     *            the security provider
     * @return the public key
     * @throws Exception
     *             is thrown if if a security error occur
     */
    public static PublicKey readPemPublicKey(final File file, final SecurityProvider securityProvider)
            throws Exception {
        final String publicKeyAsString = readPemFileAsBase64(file);
        final byte[] decoded = Base64.decodeBase64(publicKeyAsString);
        return readPublicKey(decoded, securityProvider);
    }

    /**
     * Read the public key from a pem file as base64 encoded {@link String} value.
     *
     * @param file
     *            the file in pem format that contains the public key.
     * @return the base64 encoded {@link String} value.
     * @throws IOException
     *             Signals that an I/O exception has occurred.
     */
    public static String readPemFileAsBase64(final File file) throws IOException {
        final byte[] keyBytes = Files.readAllBytes(file.toPath());
        final String publicKeyAsBase64String = new String(keyBytes).replace(BEGIN_PUBLIC_KEY_PREFIX, "")
                .replace(END_PUBLIC_KEY_SUFFIX, "");
        return publicKeyAsBase64String;
    }

    /**
     * reads a public key from a file.
     *
     * @param file
     *            the file
     * @return the public key
     * @throws Exception
     *             is thrown if if a security error occur
     */
    public static PublicKey readPemPublicKey(final File file) throws Exception {
        return readPemPublicKey(file, SecurityProvider.BC);
    }

}