| /* |
| * 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.mac; |
| |
| import javax.crypto.spec.SecretKeySpec; |
| |
| import org.apache.sshd.common.util.security.SecurityUtils; |
| |
| /** |
| * Base class for <code>Mac</code> implementations based on the JCE provider. |
| * |
| * @author <a href="mailto:dev@mina.apache.org">Apache MINA SSHD Project</a> |
| */ |
| public class BaseMac implements Mac { |
| |
| private final String algorithm; |
| private final int defbsize; |
| private final int bsize; |
| private final byte[] tmp; |
| private final boolean etmMode; |
| private javax.crypto.Mac mac; |
| private String s; |
| |
| public BaseMac(String algorithm, int bsize, int defbsize, boolean etmMode) { |
| this.algorithm = algorithm; |
| this.bsize = bsize; |
| this.defbsize = defbsize; |
| this.tmp = new byte[defbsize]; |
| this.etmMode = etmMode; |
| } |
| |
| @Override |
| public String getAlgorithm() { |
| return algorithm; |
| } |
| |
| @Override |
| public int getBlockSize() { |
| return bsize; |
| } |
| |
| @Override |
| public int getDefaultBlockSize() { |
| return defbsize; |
| } |
| |
| @Override |
| public boolean isEncryptThenMac() { |
| return etmMode; |
| } |
| |
| @Override |
| public void init(byte[] key) throws Exception { |
| if (key.length > defbsize) { |
| byte[] tmp = new byte[defbsize]; |
| System.arraycopy(key, 0, tmp, 0, defbsize); |
| key = tmp; |
| } |
| |
| SecretKeySpec skey = new SecretKeySpec(key, algorithm); |
| mac = SecurityUtils.getMac(algorithm); |
| mac.init(skey); |
| } |
| |
| @Override |
| public void updateUInt(long i) { |
| tmp[0] = (byte) (i >>> 24); |
| tmp[1] = (byte) (i >>> 16); |
| tmp[2] = (byte) (i >>> 8); |
| tmp[3] = (byte) i; |
| update(tmp, 0, 4); |
| } |
| |
| @Override |
| public void update(byte[] buf, int offset, int len) { |
| mac.update(buf, offset, len); |
| } |
| |
| @Override |
| public void doFinal(byte[] buf, int offset) throws Exception { |
| int blockSize = getBlockSize(); |
| int defaultSize = getDefaultBlockSize(); |
| if (blockSize != defaultSize) { |
| mac.doFinal(tmp, 0); |
| System.arraycopy(tmp, 0, buf, offset, blockSize); |
| } else { |
| mac.doFinal(buf, offset); |
| } |
| } |
| |
| @Override |
| public String toString() { |
| synchronized (this) { |
| if (s == null) { |
| s = getClass().getSimpleName() + "[" + getAlgorithm() + "] - " |
| + " block=" + getBlockSize() + "/" + getDefaultBlockSize() + " bytes" |
| + ", encrypt-then-mac=" + isEncryptThenMac(); |
| } |
| } |
| |
| return s; |
| } |
| } |