Copyright (c) 2006, 2016 IBM Corporation and others.
This program and the accompanying materials are made available under the
terms of the Eclipse Public License 2.0 which accompanies this distribution,
and is available at
https://www.eclipse.org/legal/epl-2.0/
SPDX-License-Identifier: EPL-2.0
Contributors: IBM Corporation - initial API and implementation
/*******************************************************************************
 * Copyright (c) 2006, 2016 IBM Corporation and others.
 *
 * This program and the accompanying materials are made available under the
 * terms of the Eclipse Public License 2.0 which accompanies this distribution,
 * and is available at
 * https://www.eclipse.org/legal/epl-2.0/
 *
 * SPDX-License-Identifier: EPL-2.0
 * 
 * Contributors: IBM Corporation - initial API and implementation
 ******************************************************************************/
package org.eclipse.osgi.internal.signedcontent;

import java.io.*;
import java.security.cert.*;
import java.util.*;
import org.eclipse.osgi.internal.hookregistry.StorageHookFactory;
import org.eclipse.osgi.signedcontent.SignedContent;
import org.eclipse.osgi.signedcontent.SignerInfo;
import org.eclipse.osgi.storage.BundleInfo.Generation;
import org.osgi.framework.BundleException;

public class SignedStorageHook extends StorageHookFactory<List<SignerInfo>, List<SignerInfo>, SignedStorageHook.StorageHookImpl> {
	private static final int STORAGE_VERSION = 4;

	@Override
	public int getStorageVersion() {
		return STORAGE_VERSION;
	}

	@Override
	public List<SignerInfo> createSaveContext() {
		return new ArrayList<>();
	}

	@Override
	public List<SignerInfo> createLoadContext(int version) {
		return new ArrayList<>();
	}

	@Override
	protected StorageHookImpl createStorageHook(Generation generation) {
		return new StorageHookImpl(generation);
	}

	static class StorageHookImpl extends StorageHookFactory.StorageHook<List<SignerInfo>, List<SignerInfo>> {
		SignedContentImpl signedContent;

		public StorageHookImpl(Generation generation) {
			super(generation, SignedStorageHook.class);
		}

		@Override
		public void initialize(Dictionary<String, String> manifest) throws BundleException {
			// do nothing
		}

		@Override
		public void load(List<SignerInfo> loadContext, DataInputStream is) throws IOException {
			boolean signed = is.readBoolean();
			if (!signed)
				return;
			int numSigners = is.readInt();
			SignerInfo[] signerInfos = new SignerInfo[numSigners];
			for (int i = 0; i < numSigners; i++)
				signerInfos[i] = readSignerInfo(is, loadContext);

			int resultsSize = is.readInt();
			Map<String, Object> contentMDResults = null;
			if (resultsSize > 0) {
				contentMDResults = new HashMap<>(resultsSize);
				for (int i = 0; i < resultsSize; i++) {
					String path = is.readUTF();
					int numEntrySigners = is.readInt();
					SignerInfo[] entrySigners = new SignerInfo[numEntrySigners];
					byte[][] entryResults = new byte[numEntrySigners][];
					for (int j = 0; j < numEntrySigners; j++) {
						entrySigners[j] = readSignerInfo(is, loadContext);
						int resultSize = is.readInt();
						entryResults[j] = new byte[resultSize];
						is.readFully(entryResults[j]);
					}
					contentMDResults.put(path, new Object[] {entrySigners, entryResults});
				}
			}
			SignedContentImpl result = new SignedContentImpl(signerInfos, contentMDResults);
			for (int i = 0; i < numSigners; i++) {
				boolean hasTSA = is.readBoolean();
				if (!hasTSA)
					continue;
				SignerInfo tsaSigner = readSignerInfo(is, loadContext);
				Date signingDate = new Date(is.readLong());
				result.addTSASignerInfo(signerInfos[i], tsaSigner, signingDate);
			}
			signedContent = result;
		}

		private SignerInfo readSignerInfo(DataInputStream is, List<SignerInfo> loadContext) throws IOException {
			int index = is.readInt();
			if (index >= 0)
				return loadContext.get(index);
			int numCerts = is.readInt();
			Certificate[] certs = new Certificate[numCerts];
			for (int i = 0; i < numCerts; i++) {
				int certSize = is.readInt();
				byte[] certBytes = new byte[certSize];
				is.readFully(certBytes);
				try {
					certs[i] = PKCS7Processor.certFact.generateCertificate(new ByteArrayInputStream(certBytes));
				} catch (CertificateException e) {
					throw new IOException(e.getMessage(), e);
				}
			}
			int anchorIdx = is.readInt();
			SignerInfoImpl result = new SignerInfoImpl(certs, anchorIdx >= 0 ? certs[anchorIdx] : null, is.readUTF());
			loadContext.add(result);
			return result;
		}

		@Override
		public void save(List<SignerInfo> saveContext, DataOutputStream os) throws IOException {
			os.writeBoolean(signedContent != null);
			if (signedContent == null)
				return;
			SignerInfo[] signerInfos = signedContent.getSignerInfos();
			os.writeInt(signerInfos.length);
			for (SignerInfo signerInfo : signerInfos) {
				saveSignerInfo(signerInfo, os, saveContext);
			}

			// keyed by entry path -> {SignerInfo[] infos, byte[][] results)}
			Map<String, Object> contentMDResults = signedContent.getContentMDResults();
			os.writeInt(contentMDResults == null ? -1 : contentMDResults.size());
			if (contentMDResults != null)
				for (Map.Entry<String, Object> entry : contentMDResults.entrySet()) {
					String path = entry.getKey();
					os.writeUTF(path);
					Object[] signerResults = (Object[]) entry.getValue();
					SignerInfo[] entrySigners = (SignerInfo[]) signerResults[0];
					byte[][] entryResults = (byte[][]) signerResults[1];
					os.writeInt(entrySigners.length);
					for (int i = 0; i < entrySigners.length; i++) {
						saveSignerInfo(entrySigners[i], os, saveContext);
						os.writeInt(entryResults[i].length);
						os.write(entryResults[i]);
					}
				}

			for (SignerInfo signerInfo : signerInfos) {
				SignerInfo tsaInfo = signedContent.getTSASignerInfo(signerInfo);
				os.writeBoolean(tsaInfo != null);
				if (tsaInfo == null)
					continue;
				saveSignerInfo(tsaInfo, os, saveContext);
				Date signingTime = signedContent.getSigningTime(signerInfo);
				os.writeLong(signingTime != null ? signingTime.getTime() : Long.MIN_VALUE);
			}
		}

		private void saveSignerInfo(SignerInfo signerInfo, DataOutputStream os, List<SignerInfo> saveContext) throws IOException {
			int cacheIdx = saveContext.indexOf(signerInfo);
			os.writeInt(cacheIdx);
			if (cacheIdx >= 0)
				return;
			Certificate[] certs = signerInfo.getCertificateChain();
			int anchorIndex = -1;
			os.writeInt(certs == null ? 0 : certs.length);
			if (certs != null)
				for (int i = 0; i < certs.length; i++) {
					if (certs[i].equals(signerInfo.getTrustAnchor()))
						anchorIndex = i;
					byte[] certBytes;
					try {
						certBytes = certs[i].getEncoded();
					} catch (CertificateEncodingException e) {
						throw new IOException(e.getMessage(), e);
					}
					os.writeInt(certBytes.length);
					os.write(certBytes);
				}
			os.writeInt(anchorIndex);
			os.writeUTF(signerInfo.getMessageDigestAlgorithm());
			saveContext.add(signerInfo);
		}

		public SignedContent getSignedContent() {
			return signedContent;
		}
	}

}