| /* SSL3.java -- SSLv3 padding scheme. |
| Copyright (C) 2004, 2006 Free Software Foundation, Inc. |
| |
| This file is a part of GNU Classpath. |
| |
| GNU Classpath is free software; you can redistribute it and/or modify |
| it under the terms of the GNU General Public License as published by |
| the Free Software Foundation; either version 2 of the License, or (at |
| your option) any later version. |
| |
| GNU Classpath 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 for more details. |
| |
| You should have received a copy of the GNU General Public License |
| along with GNU Classpath; if not, write to the Free Software |
| Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 |
| USA |
| |
| Linking this library statically or dynamically with other modules is |
| making a combined work based on this library. Thus, the terms and |
| conditions of the GNU General Public License cover the whole |
| combination. |
| |
| As a special exception, the copyright holders of this library give you |
| permission to link this library with independent modules to produce an |
| executable, regardless of the license terms of these independent |
| modules, and to copy and distribute the resulting executable under |
| terms of your choice, provided that you also meet, for each linked |
| independent module, the terms and conditions of the license of that |
| module. An independent module is a module which is not derived from |
| or based on this library. If you modify this library, you may extend |
| this exception to your version of the library, but you are not |
| obligated to do so. If you do not wish to do so, delete this |
| exception statement from your version. */ |
| |
| |
| package gnu.javax.crypto.pad; |
| |
| /** |
| * The padding scheme used by the Secure Sockets Layer, version 3. This padding |
| * scheme is used in the block-ciphered struct, e.g.: |
| * <pre> |
| * block-ciphered struct { |
| * opaque content[SSLCompressed.length]; |
| * opaque MAC[CipherSpec.hash_size]; |
| * uint8 padding[GenericBlockCipher.padding_length]; |
| * uint8 padding_length; |
| * } GenericBlockCipher; |
| * </pre> |
| * <p> |
| * Where <i>padding_length</i> is <i>cipher_block_size</i> - |
| * ((<i>SSLCompressed.length</i> + <i>CipherSpec.hash_size</i>) % |
| * <i>cipher_block_size</i>) - 1. That is, the padding is enough bytes to make |
| * the plaintext a multiple of the block size minus one, plus one additional |
| * byte for the padding length. The padding can be any arbitrary data. |
| */ |
| public class SSL3 |
| extends BasePad |
| { |
| public SSL3() |
| { |
| super("ssl3"); |
| } |
| |
| public void setup() |
| { |
| if (blockSize <= 0 || blockSize > 255) |
| throw new IllegalArgumentException("invalid block size: " + blockSize); |
| } |
| |
| public byte[] pad(final byte[] in, final int off, final int len) |
| { |
| int padlen = blockSize - (len % blockSize); |
| byte[] pad = new byte[padlen]; |
| for (int i = 0; i < padlen; i++) |
| pad[i] = (byte)(padlen - 1); |
| return pad; |
| } |
| |
| public int unpad(final byte[] in, final int off, final int len) |
| throws WrongPaddingException |
| { |
| int padlen = in[off + len - 1] & 0xFF; |
| if (padlen >= blockSize) |
| throw new WrongPaddingException(); |
| return padlen + 1; |
| } |
| } |