001    /**
002     * Licensed to the Apache Software Foundation (ASF) under one or more
003     * contributor license agreements.  See the NOTICE file distributed with
004     * this work for additional information regarding copyright ownership.
005     * The ASF licenses this file to You under the Apache License, Version 2.0
006     * (the "License"); you may not use this file except in compliance with
007     * the License.  You may obtain a copy of the License at
008     *
009     *      http://www.apache.org/licenses/LICENSE-2.0
010     *
011     * Unless required by applicable law or agreed to in writing, software
012     * distributed under the License is distributed on an "AS IS" BASIS,
013     * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
014     * See the License for the specific language governing permissions and
015     * limitations under the License.
016     */
017    package org.apache.camel.component.crypto.processor;
018    
019    import java.io.InputStream;
020    import java.lang.reflect.Field;
021    import java.security.KeyStore;
022    import java.security.NoSuchAlgorithmException;
023    import java.security.NoSuchProviderException;
024    import java.security.Signature;
025    import java.util.Map;
026    
027    import org.apache.camel.Exchange;
028    import org.apache.camel.Message;
029    import org.apache.camel.Processor;
030    import org.apache.camel.component.crypto.DigitalSignatureConfiguration;
031    import org.apache.camel.component.crypto.DigitalSignatureConstants;
032    import org.apache.camel.util.ExchangeHelper;
033    
034    import static org.apache.camel.component.crypto.DigitalSignatureConstants.KEYSTORE_ALIAS;
035    
036    public abstract class DigitalSignatureProcessor implements Processor {
037    
038        protected DigitalSignatureConfiguration config;
039    
040        public DigitalSignatureProcessor(DigitalSignatureConfiguration configuration) {
041            this.config = configuration;
042        }
043    
044        public void calculateSignature(Exchange exchange, Signature signer) throws Exception {
045            Object payload = exchange.getIn().getBody();
046            if (payload != null) {
047                InputStream payloadStream = ExchangeHelper.convertToMandatoryType(exchange, InputStream.class, payload);
048                byte[] buffer = new byte[config.getBufferSize()];
049                int read;
050                while ((read = payloadStream.read(buffer)) > 0) {
051                    signer.update(buffer, 0, read);
052                }
053            }
054        }
055    
056        protected String getAlias(Exchange exchange) throws Exception {
057            KeyStore keystore = config.getKeystore();
058            if (keystore != null) {
059                String alias = exchange.getIn().getHeader(KEYSTORE_ALIAS, String.class);
060                if (alias == null) {
061                    alias = config.getAlias();
062                }
063    
064                // if there is only one entry then use it. Document this well
065                if (alias == null && keystore.size() == 1) {
066                    alias = keystore.aliases().nextElement();
067                }
068                return alias;
069            }
070            return null;
071        }
072    
073        public void setConfig(DigitalSignatureConfiguration config) {
074            this.config = config;
075        }
076    
077        protected Signature createSignatureService() throws NoSuchAlgorithmException, NoSuchProviderException {
078            String algorithm = config.getAlgorithm();
079            String provider = config.getProvider();
080            Signature signer = provider == null ? Signature.getInstance(algorithm) : Signature.getInstance(algorithm, provider);
081            return signer;
082        }
083    
084        protected void clearMessageHeaders(Message in) {
085            if (config.getClearHeaders()) {
086                Map<String, Object> headers = in.getHeaders();
087                for (Field f : DigitalSignatureConstants.class.getFields()) {
088                    headers.remove(f.getName());
089                }
090            }
091        }
092    }