/*

 * Copyright (c) 1997, 2019, Oracle and/or its affiliates. All rights reserved.

 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.

 *

 * This code is free software; you can redistribute it and/or modify it

 * under the terms of the GNU General Public License version 2 only, as

 * published by the Free Software Foundation.  Oracle designates this

 * particular file as subject to the "Classpath" exception as provided

 * by Oracle in the LICENSE file that accompanied this code.

 *

 * This code is distributed in the hope that it will be useful, but WITHOUT

 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or

 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License

 * version 2 for more details (a copy is included in the LICENSE file that

 * accompanied this code).

 *

 * You should have received a copy of the GNU General Public License version

 * 2 along with this work; if not, write to the Free Software Foundation,

 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.

 *

 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA

 * or visit www.oracle.com if you need additional information or have any

 * questions.

 */

package java.util.jar;

import java.io.*;

import java.net.URL;

import java.util.*;

import java.security.*;

import java.security.cert.CertificateException;

import java.util.zip.ZipEntry;

import jdk.internal.util.jar.JarIndex;

import sun.security.util.ManifestDigester;

import sun.security.util.ManifestEntryVerifier;

import sun.security.util.SignatureFileVerifier;

import sun.security.util.Debug;

/**

 *

 * @author      Roland Schemers

 */

class JarVerifier {

    /* Are we debugging ? */

    static final Debug debug = Debug.getInstance("jar");

    /* a table mapping names to code signers, for jar entries that have

       had their actual hashes verified */

    private Hashtable<String, CodeSigner[]> verifiedSigners;

    /* a table mapping names to code signers, for jar entries that have

       passed the .SF/.DSA/.EC -> MANIFEST check */

    private Hashtable<String, CodeSigner[]> sigFileSigners;

    /* a hash table to hold .SF bytes */

    private Hashtable<String, byte[]> sigFileData;

    /** "queue" of pending PKCS7 blocks that we couldn't parse

     *  until we parsed the .SF file */

    private ArrayList<SignatureFileVerifier> pendingBlocks;

    /* cache of CodeSigner objects */

    private ArrayList<CodeSigner[]> signerCache;

    /* Are we parsing a block? */

    private boolean parsingBlockOrSF = false;

    /* Are we done parsing META-INF entries? */

    private boolean parsingMeta = true;

    /* Are there are files to verify? */

    private boolean anyToVerify = true;

    /* The output stream to use when keeping track of files we are interested

       in */

    private ByteArrayOutputStream baos;

    /** The ManifestDigester object */

    private volatile ManifestDigester manDig;

    /** the bytes for the manDig object */

    byte manifestRawBytes[] = null;

    /** controls eager signature validation */

    boolean eagerValidation;

    /** makes code source singleton instances unique to us */

    private Object csdomain = new Object();

    /** collect -DIGEST-MANIFEST values for blacklist */

    private List<Object> manifestDigests;

    public JarVerifier(byte rawBytes[]) {

        manifestRawBytes = rawBytes;

        sigFileSigners = new Hashtable<>();

        verifiedSigners = new Hashtable<>();

        sigFileData = new Hashtable<>(11);

        pendingBlocks = new ArrayList<>();

        baos = new ByteArrayOutputStream();

        manifestDigests = new ArrayList<>();

    }

    /**

     * This method scans to see which entry we're parsing and

     * keeps various state information depending on what type of

     * file is being parsed.

     */

    public void beginEntry(JarEntry je, ManifestEntryVerifier mev)

        throws IOException

    {

        if (je == null)

            return;

        if (debug != null) {

            debug.println("beginEntry "+je.getName());

        }

        String name = je.getName();

        /*

         * Assumptions:

         * 1. The manifest should be the first entry in the META-INF directory.

         * 2. The .SF/.DSA/.EC files follow the manifest, before any normal entries

         * 3. Any of the following will throw a SecurityException:

         *    a. digest mismatch between a manifest section and

         *       the SF section.

         *    b. digest mismatch between the actual jar entry and the manifest

         */

        if (parsingMeta) {

            String uname = name.toUpperCase(Locale.ENGLISH);

            if ((uname.startsWith("META-INF/") ||

                 uname.startsWith("/META-INF/"))) {

                if (je.isDirectory()) {

                    mev.setEntry(null, je);

                    return;

                }

                if (uname.equals(JarFile.MANIFEST_NAME) ||

                        uname.equals(JarIndex.INDEX_NAME)) {

                    return;

                }

                if (SignatureFileVerifier.isBlockOrSF(uname)) {

                    /* We parse only DSA, RSA or EC PKCS7 blocks. */

                    parsingBlockOrSF = true;

                    baos.reset();

                    mev.setEntry(null, je);

                    return;

                }

                // If a META-INF entry is not MF or block or SF, they should

                // be normal entries. According to 2 above, no more block or

                // SF will appear. Let's doneWithMeta.

            }

        }

        if (parsingMeta) {

            doneWithMeta();

        }

        if (je.isDirectory()) {

            mev.setEntry(null, je);

            return;

        }

        // be liberal in what you accept. If the name starts with ./, remove

        // it as we internally canonicalize it with out the ./.

        if (name.startsWith("./"))

            name = name.substring(2);

        // be liberal in what you accept. If the name starts with /, remove

        // it as we internally canonicalize it with out the /.

        if (name.startsWith("/"))

            name = name.substring(1);

        // only set the jev object for entries that have a signature

        // (either verified or not)

        if (!name.equals(JarFile.MANIFEST_NAME)) {

            if (sigFileSigners.get(name) != null ||

                    verifiedSigners.get(name) != null) {

                mev.setEntry(name, je);

                return;

            }

        }

        // don't compute the digest for this entry

        mev.setEntry(null, je);

        return;

    }

    /**

     * update a single byte.

     */

    public void update(int b, ManifestEntryVerifier mev)

        throws IOException

    {

        if (b != -1) {

            if (parsingBlockOrSF) {

                baos.write(b);

            } else {

                mev.update((byte)b);

            }

        } else {

            processEntry(mev);

        }

    }

    /**

     * update an array of bytes.

     */

    public void update(int n, byte[] b, int off, int len,

                       ManifestEntryVerifier mev)

        throws IOException

    {

        if (n != -1) {

            if (parsingBlockOrSF) {

                baos.write(b, off, n);

            } else {

                mev.update(b, off, n);

            }

        } else {

            processEntry(mev);

        }

    }

    /**

     * called when we reach the end of entry in one of the read() methods.

     */

    private void processEntry(ManifestEntryVerifier mev)

        throws IOException

    {

        if (!parsingBlockOrSF) {

            JarEntry je = mev.getEntry();

            if ((je != null) && (je.signers == null)) {

                je.signers = mev.verify(verifiedSigners, sigFileSigners);

                je.certs = mapSignersToCertArray(je.signers);

            }

        } else {

            try {

                parsingBlockOrSF = false;

                if (debug != null) {

                    debug.println("processEntry: processing block");

                }

                String uname = mev.getEntry().getName()

                                             .toUpperCase(Locale.ENGLISH);

                if (uname.endsWith(".SF")) {

                    String key = uname.substring(0, uname.length()-3);

                    byte bytes[] = baos.toByteArray();

                    // add to sigFileData in case future blocks need it

                    sigFileData.put(key, bytes);

                    // check pending blocks, we can now process

                    // anyone waiting for this .SF file

                    for (SignatureFileVerifier sfv : pendingBlocks) {

                        if (sfv.needSignatureFile(key)) {

                            if (debug != null) {

                                debug.println(

                                 "processEntry: processing pending block");

                            }

                            sfv.setSignatureFile(bytes);

                            sfv.process(sigFileSigners, manifestDigests);

                        }

                    }

                    return;

                }

                // now we are parsing a signature block file

                String key = uname.substring(0, uname.lastIndexOf('.'));

                if (signerCache == null)

                    signerCache = new ArrayList<>();

                if (manDig == null) {

                    synchronized(manifestRawBytes) {

                        if (manDig == null) {

                            manDig = new ManifestDigester(manifestRawBytes);

                            manifestRawBytes = null;

                        }

                    }

                }

                SignatureFileVerifier sfv =

                  new SignatureFileVerifier(signerCache,

                                            manDig, uname, baos.toByteArray());

                if (sfv.needSignatureFileBytes()) {

                    // see if we have already parsed an external .SF file

                    byte[] bytes = sigFileData.get(key);

                    if (bytes == null) {

                        // put this block on queue for later processing

                        // since we don't have the .SF bytes yet

                        // (uname, block);

                        if (debug != null) {

                            debug.println("adding pending block");

                        }

                        pendingBlocks.add(sfv);

                        return;

                    } else {

                        sfv.setSignatureFile(bytes);

                    }

                }

                sfv.process(sigFileSigners, manifestDigests);

            } catch (IOException | CertificateException |

                    NoSuchAlgorithmException | SignatureException e) {

                if (debug != null) debug.println("processEntry caught: "+e);

                // ignore and treat as unsigned

            }

        }

    }

    /**

     * Return an array of java.security.cert.Certificate objects for

     * the given file in the jar.

     * @deprecated

     */

    @Deprecated

    public java.security.cert.Certificate[] getCerts(String name)

    {

        return mapSignersToCertArray(getCodeSigners(name));

    }

    public java.security.cert.Certificate[] getCerts(JarFile jar, JarEntry entry)

    {

        return mapSignersToCertArray(getCodeSigners(jar, entry));

    }

    /**

     * return an array of CodeSigner objects for

     * the given file in the jar. this array is not cloned.

     *

     */

    public CodeSigner[] getCodeSigners(String name)

    {

        return verifiedSigners.get(name);

    }

    public CodeSigner[] getCodeSigners(JarFile jar, JarEntry entry)

    {

        String name = entry.getName();

        if (eagerValidation && sigFileSigners.get(name) != null) {

            /*

             * Force a read of the entry data to generate the

             * verification hash.

             */

            try {

                InputStream s = jar.getInputStream(entry);

                byte[] buffer = new byte[1024];

                int n = buffer.length;

                while (n != -1) {

                    n = s.read(buffer, 0, buffer.length);

                }

                s.close();

            } catch (IOException e) {

            }

        }

        return getCodeSigners(name);

    }

    /*

     * Convert an array of signers into an array of concatenated certificate

     * arrays.

     */

    private static java.security.cert.Certificate[] mapSignersToCertArray(

        CodeSigner[] signers) {

        if (signers != null) {

            ArrayList<java.security.cert.Certificate> certChains = new ArrayList<>();

            for (CodeSigner signer : signers) {

                certChains.addAll(

                    signer.getSignerCertPath().getCertificates());

            }

            // Convert into a Certificate[]

            return certChains.toArray(

                    new java.security.cert.Certificate[certChains.size()]);

        }

        return null;

    }

    /**

     * returns true if there no files to verify.

     * should only be called after all the META-INF entries

     * have been processed.

     */

    boolean nothingToVerify()

    {

        return (anyToVerify == false);

    }

    /**

     * called to let us know we have processed all the

     * META-INF entries, and if we re-read one of them, don't

     * re-process it. Also gets rid of any data structures

     * we needed when parsing META-INF entries.

     */

    void doneWithMeta()

    {

        parsingMeta = false;

        anyToVerify = !sigFileSigners.isEmpty();

        baos = null;

        sigFileData = null;

        pendingBlocks = null;

        signerCache = null;

        manDig = null;

        // MANIFEST.MF is always treated as signed and verified,

        // move its signers from sigFileSigners to verifiedSigners.

        if (sigFileSigners.containsKey(JarFile.MANIFEST_NAME)) {

            CodeSigner[] codeSigners = sigFileSigners.remove(JarFile.MANIFEST_NAME);

            verifiedSigners.put(JarFile.MANIFEST_NAME, codeSigners);

        }

    }

    static class VerifierStream extends java.io.InputStream {

        private InputStream is;

        private JarVerifier jv;

        private ManifestEntryVerifier mev;

        private long numLeft;

        VerifierStream(Manifest man,

                       JarEntry je,

                       InputStream is,

                       JarVerifier jv) throws IOException

        {

            this.is = Objects.requireNonNull(is);

            this.jv = jv;

            this.mev = new ManifestEntryVerifier(man);

            this.jv.beginEntry(je, mev);

            this.numLeft = je.getSize();

            if (this.numLeft == 0)

                this.jv.update(-1, this.mev);

        }

        public int read() throws IOException

        {

            ensureOpen();

            if (numLeft > 0) {

                int b = is.read();

                jv.update(b, mev);

                numLeft--;

                if (numLeft == 0)

                    jv.update(-1, mev);

                return b;

            } else {

                return -1;

            }

        }

        public int read(byte b[], int off, int len) throws IOException {

            ensureOpen();

            if ((numLeft > 0) && (numLeft < len)) {

                len = (int)numLeft;

            }

            if (numLeft > 0) {

                int n = is.read(b, off, len);

                jv.update(n, b, off, len, mev);

                numLeft -= n;

                if (numLeft == 0)

                    jv.update(-1, b, off, len, mev);

                return n;

            } else {

                return -1;

            }

        }

        public void close()

            throws IOException

        {

            if (is != null)

                is.close();

            is = null;

            mev = null;

            jv = null;

        }

        public int available() throws IOException {

            ensureOpen();

            return is.available();

        }

        private void ensureOpen() throws IOException {

            if (is == null) {

                throw new IOException("stream closed");

            }

        }

    }

    // Extended JavaUtilJarAccess CodeSource API Support