Java tutorial
/** * 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; import java.io.IOException; import java.io.UnsupportedEncodingException; import java.security.InvalidKeyException; import java.security.NoSuchAlgorithmException; import java.security.PublicKey; import java.security.spec.InvalidKeySpecException; import javax.crypto.BadPaddingException; import javax.crypto.Cipher; import javax.crypto.IllegalBlockSizeException; import javax.crypto.NoSuchPaddingException; import org.apache.commons.codec.binary.Hex; import de.alpharogroup.crypto.algorithm.KeyPairWithModeAndPaddingAlgorithm; import lombok.AccessLevel; import lombok.Getter; import lombok.Setter; /** * The class {@link PublicKeyHexEncryptor} can encrypt characters with his public key. */ public class PublicKeyHexEncryptor { /** * The Cipher object. */ @Getter @Setter private Cipher cipher; /** * The flag initialized that indicates if the cypher is initialized for decryption. * * @return true, if is initialized */ @Getter(value = AccessLevel.PRIVATE) private boolean initialized; /** * The public key. */ @Getter private final PublicKey publicKey; /** * Instantiates a new {@link PublicKeyHexEncryptor} with the given {@link PublicKey}. * * @param publicKey * The public key. */ public PublicKeyHexEncryptor(final PublicKey publicKey) { this.publicKey = publicKey; } /** * Encrypt the given String. * * @param string * The String to encrypt. * @return The encrypted String. * @throws InvalidKeyException * the invalid key exception is thrown if initialization of the cypher object fails. * @throws NoSuchAlgorithmException * is thrown if instantiation of the cypher object fails. * @throws NoSuchPaddingException * is thrown if instantiation of the cypher object fails. * @throws IllegalBlockSizeException * is thrown if {@link Cipher#doFinal(byte[])} fails. * @throws BadPaddingException * is thrown if {@link Cipher#doFinal(byte[])} fails. * @throws InvalidKeySpecException * is thrown if generation of the SecretKey object fails. * @throws IOException * Signals that an I/O exception has occurred. */ public String encrypt(final String string) throws InvalidKeyException, NoSuchAlgorithmException, NoSuchPaddingException, IllegalBlockSizeException, BadPaddingException, InvalidKeySpecException, IOException { initialize(); final byte[] utf8 = string.getBytes("UTF-8"); final byte[] encrypt = this.cipher.doFinal(utf8); final char[] original = Hex.encodeHex(encrypt, false); return new String(original); } /** * Initializes the {@link PublicKeyHexEncryptor} object. * * @throws UnsupportedEncodingException * is thrown by get the byte array of the private key String object fails. * @throws NoSuchAlgorithmException * is thrown if instantiation of the cypher object fails. * @throws NoSuchPaddingException * is thrown if instantiation of the cypher object fails. * @throws InvalidKeyException * the invalid key exception is thrown if initialization of the cypher object fails. * @throws InvalidKeySpecException * is thrown if generation of the SecretKey object fails. */ private void initialize() throws NoSuchAlgorithmException, InvalidKeySpecException, UnsupportedEncodingException, NoSuchPaddingException, InvalidKeyException { if (!isInitialized()) { cipher = Cipher.getInstance( KeyPairWithModeAndPaddingAlgorithm.RSA_ECB_OAEPWithSHA1AndMGF1Padding.getAlgorithm()); cipher.init(Cipher.ENCRYPT_MODE, this.publicKey); } } }