Copyright (c) 2006, 2013 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, 2013 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.IOException;
import java.io.InputStream;
import java.net.URL;
import java.security.*;
import java.security.cert.*;
import java.util.Date;
import org.eclipse.osgi.signedcontent.*;
import org.eclipse.osgi.storage.bundlefile.*;
import org.eclipse.osgi.util.NLS;

This class wraps a Repository of classes and resources to check and enforce
signatures. It requires full signing of the manifest by all signers. If no
signatures are found, the classes and resources are retrieved without checks.
/**
 * This class wraps a Repository of classes and resources to check and enforce
 * signatures. It requires full signing of the manifest by all signers. If no
 * signatures are found, the classes and resources are retrieved without checks.
 */
public class SignedBundleFile extends BundleFileWrapper implements SignedContentConstants, SignedContent {
	SignedContentImpl signedContent;
	private final int supportFlags;
	private final SignedBundleHook signedBundleHook;

	SignedBundleFile(BundleFile bundleFile, SignedContentImpl signedContent, int supportFlags, SignedBundleHook signedBundleHook) {
		super(bundleFile);
		this.signedContent = signedContent;
		this.supportFlags = supportFlags;
		this.signedBundleHook = signedBundleHook;
	}

	void initializeSignedContent() throws IOException, InvalidKeyException, SignatureException, CertificateException, NoSuchAlgorithmException, NoSuchProviderException {
		if (signedContent == null) {
			SignatureBlockProcessor signatureProcessor = new SignatureBlockProcessor(this, supportFlags, signedBundleHook);
			signedContent = signatureProcessor.process();
			if (signedContent != null)
				signedBundleHook.determineTrust(signedContent, supportFlags);
		}
	}

	@Override
	public BundleEntry getEntry(String path) {
		// strip off leading slashes so we can ensure the path matches the one provided in the manifest.
		if (path.length() > 0 && path.charAt(0) == '/')
			path = path.substring(1);
		BundleEntry be = getBundleFile().getEntry(path);
		if ((supportFlags & SignedBundleHook.VERIFY_RUNTIME) == 0 || signedContent == null)
			return be;
		if (path.startsWith(META_INF)) {
			int lastSlash = path.lastIndexOf('/');
			if (lastSlash == META_INF.length() - 1) {
				if (path.equals(META_INF_MANIFEST_MF) || path.endsWith(DOT_DSA) || path.endsWith(DOT_RSA) || path.endsWith(DOT_SF) || path.indexOf(SIG_DASH) == META_INF.length())
					return be;
				SignedContentEntry signedEntry = signedContent.getSignedEntry(path);
				if (signedEntry == null)
					// TODO this is to allow 1.4 signed bundles to work, it would be better if we could detect 1.4 signed bundles and only do this for them.
					return be;
			}
		}
		if (be == null) {
			// double check that no signer thinks it should exist
			SignedContentEntry signedEntry = signedContent.getSignedEntry(path);
			if (signedEntry != null)
				throw new SecurityException(NLS.bind(SignedContentMessages.file_is_removed_from_jar, path, getBaseFile().toString()));
			return null;
		}
		return new SignedBundleEntry(be);
	}

	class SignedBundleEntry extends BundleEntry {
		BundleEntry nestedEntry;

		SignedBundleEntry(BundleEntry nestedEntry) {
			this.nestedEntry = nestedEntry;
		}

		@Override
		public InputStream getInputStream() throws IOException {
			InputStream in = signedContent.getDigestInputStream(nestedEntry);
			if (in == null)
				throw new SecurityException("Corrupted file: the digest does not exist for the file " + nestedEntry.getName()); //$NON-NLS-1$
			return in;
		}

		@Override
		public long getSize() {
			return nestedEntry.getSize();
		}

		@Override
		public String getName() {
			return nestedEntry.getName();
		}

		@Override
		public long getTime() {
			return nestedEntry.getTime();
		}

		@Override
		public URL getLocalURL() {
			return nestedEntry.getLocalURL();
		}

		@Override
		public URL getFileURL() {
			return nestedEntry.getFileURL();
		}

	}

	SignedContentImpl getSignedContent() {
		return signedContent;
	}

	@Override
	public SignedContentEntry[] getSignedEntries() {
		return signedContent == null ? null : signedContent.getSignedEntries();
	}

	@Override
	public SignedContentEntry getSignedEntry(String name) {
		return signedContent == null ? null : signedContent.getSignedEntry(name);
	}

	@Override
	public SignerInfo[] getSignerInfos() {
		return signedContent == null ? null : signedContent.getSignerInfos();
	}

	@Override
	public Date getSigningTime(SignerInfo signerInfo) {
		return signedContent == null ? null : signedContent.getSigningTime(signerInfo);
	}

	@Override
	public SignerInfo getTSASignerInfo(SignerInfo signerInfo) {
		return signedContent == null ? null : signedContent.getTSASignerInfo(signerInfo);
	}

	@Override
	public boolean isSigned() {
		return signedContent == null ? false : signedContent.isSigned();
	}

	@Override
	public void checkValidity(SignerInfo signerInfo) throws CertificateExpiredException, CertificateNotYetValidException {
		if (signedContent != null)
			signedContent.checkValidity(signerInfo);
	}

}