/*
 * 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
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 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
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 * See the License for the specific language governing permissions and
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package org.apache.commons.vfs2.util;

import javax.crypto.Cipher;
import javax.crypto.spec.SecretKeySpec;

Allows passwords to be encrypted and decrypted.

Warning: This uses AES128 with a fixed encryption key. This is only an obfuscation no cryptographic secure protection.

Since:2.0
/** * Allows passwords to be encrypted and decrypted. * <p> * Warning: This uses AES128 with a fixed encryption key. This is only an obfuscation no cryptographic secure * protection. * </p> * * @since 2.0 */
public class DefaultCryptor implements Cryptor { private static final char[] HEX_CHARS = { '0', '1', '2', '3', '4', '5', '6', '7', '8', '9', 'A', 'B', 'C', 'D', 'E', 'F' }; private static final byte[] KEY_BYTES = { 0x41, 0x70, 0x61, 0x63, 0x68, 0x65, 0x43, 0x6F, 0x6D, 0x6D, 0x6F, 0x6E, 0x73, 0x56, 0x46, 0x53 }; private static final int INDEX_NOT_FOUND = -1; private static final int BITS_IN_HALF_BYTE = 4; private static final char MASK = 0x0f;
Encrypt the plain text password.

Warning: This uses AES128 with a fixed encryption key. This is only an obfuscation no cryptographic secure protection.

Params:
  • plainKey – The password.
Throws:
Returns:The encrypted password String.
/** * Encrypt the plain text password. * <p> * Warning: This uses AES128 with a fixed encryption key. This is only an obfuscation no cryptographic secure * protection. * * @param plainKey The password. * @return The encrypted password String. * @throws Exception If an error occurs. */
@Override public String encrypt(final String plainKey) throws Exception { final byte[] input = plainKey.getBytes(); final SecretKeySpec key = new SecretKeySpec(KEY_BYTES, "AES"); final Cipher cipher = Cipher.getInstance("AES"); // encryption pass cipher.init(Cipher.ENCRYPT_MODE, key); final byte[] cipherText = new byte[cipher.getOutputSize(input.length)]; int ctLength = cipher.update(input, 0, input.length, cipherText, 0); ctLength += cipher.doFinal(cipherText, ctLength); return encode(cipherText); }
Decrypts the password.
Params:
  • encryptedKey – the encrypted password.
Throws:
Returns:The plain text password.
/** * Decrypts the password. * * @param encryptedKey the encrypted password. * @return The plain text password. * @throws Exception If an error occurs. */
@Override public String decrypt(final String encryptedKey) throws Exception { final SecretKeySpec key = new SecretKeySpec(KEY_BYTES, "AES"); final Cipher cipher = Cipher.getInstance("AES"); cipher.init(Cipher.DECRYPT_MODE, key); final byte[] decoded = decode(encryptedKey); final byte[] plainText = new byte[cipher.getOutputSize(decoded.length)]; int ptLength = cipher.update(decoded, 0, decoded.length, plainText, 0); ptLength += cipher.doFinal(plainText, ptLength); return new String(plainText).substring(0, ptLength); }
Hex-encode bytes.
/** Hex-encode bytes. */
private String encode(final byte[] bytes) { final StringBuilder builder = new StringBuilder(); for (final byte b : bytes) { builder.append(HEX_CHARS[(b >> BITS_IN_HALF_BYTE) & MASK]); builder.append(HEX_CHARS[b & MASK]); } return builder.toString(); }
Decodes Hex-Bytes.
/** Decodes Hex-Bytes. */
private byte[] decode(final String str) { final char[] chars = str.toCharArray(); final int length = chars.length / 2; final byte[] decoded = new byte[length]; if (length * 2 != chars.length) { throw new IllegalArgumentException("The given string must have even number of hex chars."); } int index = 0; for (int i = 0; i < length; i++) { final int id1 = indexOf(HEX_CHARS, chars[index++]); if (id1 == INDEX_NOT_FOUND) { throw new IllegalArgumentException( "Character " + chars[index-1] + " at position " + (index-1) + " is not a valid hexidecimal character"); } final int id2 = indexOf(HEX_CHARS, chars[index++]); if (id2 == INDEX_NOT_FOUND) { throw new IllegalArgumentException( "Character " + chars[index-1] + " at position " + (index-1) + " is not a valid hexidecimal character"); } decoded[i] = (byte) ((id1 << BITS_IN_HALF_BYTE) | id2); } return decoded; } private int indexOf(final char[] array, final char valueToFind) { if (array == null) { return INDEX_NOT_FOUND; } for (int i = 0; i < array.length; i++) { if (valueToFind == array[i]) { return i; } } return INDEX_NOT_FOUND; } }