001/* 002 * (C) Copyright 2006-2007 Nuxeo SA (http://nuxeo.com/) and others. 003 * 004 * Licensed under the Apache 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.apache.org/licenses/LICENSE-2.0 009 * 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 * 016 * Contributors: 017 * Nuxeo - initial API and implementation 018 * 019 * $Id$ 020 */ 021 022package org.nuxeo.ecm.platform.filemanager.core.listener; 023 024import java.io.IOException; 025import java.security.DigestInputStream; 026import java.security.MessageDigest; 027import java.security.NoSuchAlgorithmException; 028import java.util.List; 029 030import org.apache.commons.logging.Log; 031import org.apache.commons.logging.LogFactory; 032import org.nuxeo.common.utils.Base64; 033import org.nuxeo.ecm.core.api.Blob; 034import org.nuxeo.ecm.core.api.DocumentModel; 035import org.nuxeo.ecm.core.api.PropertyException; 036import org.nuxeo.ecm.core.api.model.Property; 037import org.nuxeo.ecm.core.event.Event; 038import org.nuxeo.ecm.core.event.EventContext; 039import org.nuxeo.ecm.core.event.EventListener; 040import org.nuxeo.ecm.core.event.impl.DocumentEventContext; 041import org.nuxeo.ecm.platform.filemanager.api.FileManager; 042import org.nuxeo.runtime.api.Framework; 043 044import static org.nuxeo.ecm.core.api.event.DocumentEventTypes.ABOUT_TO_CREATE; 045import static org.nuxeo.ecm.core.api.event.DocumentEventTypes.BEFORE_DOC_UPDATE; 046 047public class DigestComputer implements EventListener { 048 049 private boolean initDone = false; 050 051 private List<String> xpathFields; 052 053 private String digestAlgo = "sha-256"; 054 055 private Boolean activateDigestComputation = false; 056 057 private static final Log log = LogFactory.getLog(DigestComputer.class); 058 059 private boolean initIfNeeded() { 060 if (!initDone) { 061 FileManager fm = Framework.getService(FileManager.class); 062 xpathFields = fm.getFields(); 063 digestAlgo = fm.getDigestAlgorithm(); 064 activateDigestComputation = fm.isDigestComputingEnabled(); 065 initDone = true; 066 } 067 return initDone; 068 } 069 070 private void addDigestToDocument(DocumentModel doc) { 071 for (String xpathField : xpathFields) { 072 Property blobProp = null; 073 try { 074 blobProp = doc.getProperty(xpathField); 075 } catch (PropertyException e) { 076 log.debug("Property " + xpathField + " not found on doc, skipping"); 077 } 078 if (blobProp != null && !blobProp.isPhantom() && blobProp.isDirty()) { 079 try { 080 Blob blob = (Blob) blobProp.getValue(); 081 if (blob != null) { 082 String digest = computeDigest(blob); 083 if (!digest.equals(blob.getDigest())) { 084 blob.setDigest(digest); 085 } 086 } 087 } catch (PropertyException | IOException e) { 088 log.error("Error while trying to save blob digest", e); 089 } 090 } 091 } 092 } 093 094 private String computeDigest(Blob blob) throws IOException { 095 096 MessageDigest md; 097 try { 098 md = MessageDigest.getInstance(digestAlgo); 099 } catch (NoSuchAlgorithmException e) { 100 throw new RuntimeException(e); 101 } 102 103 DigestInputStream dis = new DigestInputStream(blob.getStream(), md); 104 while (dis.available() > 0) { 105 dis.read(); 106 } 107 byte[] b = md.digest(); 108 return Base64.encodeBytes(b); 109 } 110 111 public void handleEvent(Event event) { 112 if (!initIfNeeded()) { 113 return; 114 } 115 116 if (!activateDigestComputation) { 117 return; 118 } 119 120 EventContext ctx = event.getContext(); 121 String evt = event.getName(); 122 if (ABOUT_TO_CREATE.equals(evt) || BEFORE_DOC_UPDATE.equals(evt)) { 123 124 if (ctx instanceof DocumentEventContext) { 125 DocumentEventContext docCtx = (DocumentEventContext) ctx; 126 DocumentModel doc = docCtx.getSourceDocument(); 127 if (doc == null || doc.isProxy()) { 128 return; 129 } 130 addDigestToDocument(doc); 131 } 132 } 133 } 134 135}