001/**
002 * Copyright 2005-2014 The Kuali Foundation
003 *
004 * Licensed under the Educational Community License, Version 2.0 (the "License");
005 * you may not use this file except in compliance with the License.
006 * You may obtain a copy of the License at
007 *
008 * http://www.opensource.org/licenses/ecl2.php
009 *
010 * Unless required by applicable law or agreed to in writing, software
011 * distributed under the License is distributed on an "AS IS" BASIS,
012 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
013 * See the License for the specific language governing permissions and
014 * limitations under the License.
015 */
016package org.kuali.rice.ksb.security;
017
018import java.io.ByteArrayInputStream;
019import java.io.IOException;
020import java.security.Signature;
021import java.security.cert.CertificateFactory;
022
023import javax.servlet.ServletInputStream;
024import javax.servlet.http.HttpServletRequest;
025import javax.servlet.http.HttpServletRequestWrapper;
026
027import org.apache.commons.codec.binary.Base64;
028import org.apache.commons.lang.StringUtils;
029import org.kuali.rice.ksb.service.KSBServiceLocator;
030import org.kuali.rice.ksb.util.KSBConstants;
031
032/**
033 * An HttpServletRequestWrapper which will wraps the underlying request's InputStream in a 
034 * SignatureVerifyingInputStream which will verify the digital signature of the request after 
035 * all of the data has been read from the input stream.
036 * 
037 * @author Kuali Rice Team (rice.collab@kuali.org)
038 */
039public class SignatureVerifyingRequestWrapper extends HttpServletRequestWrapper {
040
041        private byte[] digitalSignature;
042        private Signature signature;
043        
044        public SignatureVerifyingRequestWrapper(HttpServletRequest request) {
045                super(request);
046                String encodedSignature = request.getHeader(KSBConstants.DIGITAL_SIGNATURE_HEADER);
047                if (StringUtils.isEmpty(encodedSignature)) {
048                        throw new RuntimeException("A digital signature was required on the request but none was found.");
049                }
050                String verificationAlias = request.getHeader(KSBConstants.KEYSTORE_ALIAS_HEADER);
051                String encodedCertificate = request.getHeader(KSBConstants.KEYSTORE_CERTIFICATE_HEADER);
052                if ( (StringUtils.isEmpty(verificationAlias)) && (StringUtils.isEmpty(encodedCertificate)) ) {
053            throw new RuntimeException("A verification alias or certificate was required on the request but neither was found.");
054                }
055                try {
056            this.digitalSignature = Base64.decodeBase64(encodedSignature.getBytes("UTF-8"));
057            if (StringUtils.isNotBlank(encodedCertificate)) {
058                byte[] certificate = Base64.decodeBase64(encodedCertificate.getBytes("UTF-8"));
059                CertificateFactory cf = CertificateFactory.getInstance("X.509");
060                this.signature = KSBServiceLocator.getDigitalSignatureService().getSignatureForVerification(cf.generateCertificate(new ByteArrayInputStream(certificate)));
061            } else if (StringUtils.isNotBlank(verificationAlias)) {
062                this.signature = KSBServiceLocator.getDigitalSignatureService().getSignatureForVerification(verificationAlias);
063            }
064                } catch (Exception e) {
065                        throw new RuntimeException("Failed to initialize digital signature verification.", e);
066                }
067        }
068
069        @Override
070        public ServletInputStream getInputStream() throws IOException {
071                return new SignatureVerifyingInputStream(this.digitalSignature, this.signature, super.getInputStream());
072        }
073        
074}