| // Copyright 2012-2013 The Apache Software Foundation |
| // |
| // Licensed 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.tapestry5.internal.util; |
| |
| import org.apache.commons.codec.binary.Base64; |
| import org.apache.tapestry5.ioc.util.ExceptionUtils; |
| |
| import javax.crypto.Mac; |
| import java.io.IOException; |
| import java.io.OutputStream; |
| import java.security.Key; |
| |
| /** |
| * An output stream that wraps around a {@link Mac} (message authentication code algorithm). This is currently |
| * used for symmetric (private) keys, but in theory could be used with assymetric (public/private) keys. |
| * |
| * @since 5.3.6 |
| */ |
| public class MacOutputStream extends OutputStream |
| { |
| private final Mac mac; |
| |
| public static MacOutputStream streamFor(Key key) throws IOException |
| { |
| try |
| { |
| Mac mac = Mac.getInstance(key.getAlgorithm()); |
| mac.init(key); |
| |
| return new MacOutputStream(mac); |
| } catch (Exception ex) |
| { |
| throw new IOException("Unable to create MacOutputStream: " + ExceptionUtils.toMessage(ex), ex); |
| } |
| } |
| |
| public MacOutputStream(Mac mac) |
| { |
| assert mac != null; |
| |
| this.mac = mac; |
| } |
| |
| /** |
| * Should only be invoked once, immediately after this stream is closed; it generates the final MAC result, and |
| * returns it as a Base64 encoded string. |
| * |
| * @return Base64 encoded MAC result |
| */ |
| public String getResult() |
| { |
| byte[] result = mac.doFinal(); |
| |
| return new String(Base64.encodeBase64(result)); |
| } |
| |
| @Override |
| public void write(int b) throws IOException |
| { |
| mac.update((byte) b); |
| } |
| |
| @Override |
| public void write(byte[] b) throws IOException |
| { |
| mac.update(b); |
| } |
| |
| @Override |
| public void write(byte[] b, int off, int len) throws IOException |
| { |
| mac.update(b, off, len); |
| } |
| } |