/*
 * Copyright (c) 1997, 2018, 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.lang.ref.SoftReference;
import java.net.URL;
import java.util.*;
import java.util.stream.Stream;
import java.util.stream.StreamSupport;
import java.util.zip.*;
import java.security.CodeSigner;
import java.security.cert.Certificate;
import java.security.AccessController;
import java.security.CodeSource;
import sun.misc.IOUtils;
import sun.security.action.GetPropertyAction;
import sun.security.util.ManifestEntryVerifier;
import sun.misc.SharedSecrets;
import sun.security.util.SignatureFileVerifier;

The JarFile class is used to read the contents of a jar file
from any file that can be opened with java.io.RandomAccessFile.
It extends the class java.util.zip.ZipFile with support
for reading an optional Manifest entry. The
Manifest can be used to specify meta-information about the
jar file and its entries.
 Unless otherwise noted, passing a null argument to a constructor or method in this class will cause a NullPointerException to be thrown. If the verify flag is on when opening a signed jar file, the content of the file is verified against its signature embedded inside the file. Please note that the verification process does not include validating the signer's certificate. A caller should inspect the return value of JarEntry.getCodeSigners() to further determine if the signature can be trusted. 
Author:
 David Connelly
See Also:
Manifest
ZipFile
JarEntry
Since:
  1.2/**
 * The <code>JarFile</code> class is used to read the contents of a jar file
 * from any file that can be opened with <code>java.io.RandomAccessFile</code>.
 * It extends the class <code>java.util.zip.ZipFile</code> with support
 * for reading an optional <code>Manifest</code> entry. The
 * <code>Manifest</code> can be used to specify meta-information about the
 * jar file and its entries.
 *
 * <p> Unless otherwise noted, passing a <tt>null</tt> argument to a constructor
 * or method in this class will cause a {@link NullPointerException} to be
 * thrown.
 *
 * If the verify flag is on when opening a signed jar file, the content of the
 * file is verified against its signature embedded inside the file. Please note
 * that the verification process does not include validating the signer's
 * certificate. A caller should inspect the return value of
 * {@link JarEntry#getCodeSigners()} to further determine if the signature
 * can be trusted.
 *
 * @author  David Connelly
 * @see     Manifest
 * @see     java.util.zip.ZipFile
 * @see     java.util.jar.JarEntry
 * @since   1.2
 */
public
class JarFile extends ZipFile {
    private SoftReference<Manifest> manRef;
    private JarEntry manEntry;
    private JarVerifier jv;
    private boolean jvInitialized;
    private boolean verify;

    // indicates if Class-Path attribute present (only valid if hasCheckedSpecialAttributes true)
    private boolean hasClassPathAttribute;
    // true if manifest checked for special attributes
    private volatile boolean hasCheckedSpecialAttributes;

    // Set up JavaUtilJarAccess in SharedSecrets
    static {
        SharedSecrets.setJavaUtilJarAccess(new JavaUtilJarAccessImpl());
    }

    
The JAR manifest file name.
/**
     * The JAR manifest file name.
     */
    public static final String MANIFEST_NAME = "META-INF/MANIFEST.MF";

    
Creates a new JarFile to read from the specified
file name. The JarFile will be verified if
it is signed.
Params:
name – the name of the jar file to be opened for reading
Throws:
IOException – if an I/O error has occurred
SecurityException – if access to the file is denied
        by the SecurityManager/**
     * Creates a new <code>JarFile</code> to read from the specified
     * file <code>name</code>. The <code>JarFile</code> will be verified if
     * it is signed.
     * @param name the name of the jar file to be opened for reading
     * @throws IOException if an I/O error has occurred
     * @throws SecurityException if access to the file is denied
     *         by the SecurityManager
     */
    public JarFile(String name) throws IOException {
        this(new File(name), true, ZipFile.OPEN_READ);
    }

    
Creates a new JarFile to read from the specified
file name.
Params:
name – the name of the jar file to be opened for reading
verify – whether or not to verify the jar file if
it is signed.
Throws:
IOException – if an I/O error has occurred
SecurityException – if access to the file is denied
        by the SecurityManager/**
     * Creates a new <code>JarFile</code> to read from the specified
     * file <code>name</code>.
     * @param name the name of the jar file to be opened for reading
     * @param verify whether or not to verify the jar file if
     * it is signed.
     * @throws IOException if an I/O error has occurred
     * @throws SecurityException if access to the file is denied
     *         by the SecurityManager
     */
    public JarFile(String name, boolean verify) throws IOException {
        this(new File(name), verify, ZipFile.OPEN_READ);
    }

    
Creates a new JarFile to read from the specified
File object. The JarFile will be verified if
it is signed.
Params:
file – the jar file to be opened for reading
Throws:
IOException – if an I/O error has occurred
SecurityException – if access to the file is denied
        by the SecurityManager/**
     * Creates a new <code>JarFile</code> to read from the specified
     * <code>File</code> object. The <code>JarFile</code> will be verified if
     * it is signed.
     * @param file the jar file to be opened for reading
     * @throws IOException if an I/O error has occurred
     * @throws SecurityException if access to the file is denied
     *         by the SecurityManager
     */
    public JarFile(File file) throws IOException {
        this(file, true, ZipFile.OPEN_READ);
    }


    
Creates a new JarFile to read from the specified
File object.
Params:
file – the jar file to be opened for reading
verify – whether or not to verify the jar file if
it is signed.
Throws:
IOException – if an I/O error has occurred
SecurityException – if access to the file is denied
        by the SecurityManager./**
     * Creates a new <code>JarFile</code> to read from the specified
     * <code>File</code> object.
     * @param file the jar file to be opened for reading
     * @param verify whether or not to verify the jar file if
     * it is signed.
     * @throws IOException if an I/O error has occurred
     * @throws SecurityException if access to the file is denied
     *         by the SecurityManager.
     */
    public JarFile(File file, boolean verify) throws IOException {
        this(file, verify, ZipFile.OPEN_READ);
    }


    
Creates a new JarFile to read from the specified
File object in the specified mode.  The mode argument
must be either OPEN_READ or OPEN_READ | OPEN_DELETE.
Params:
file – the jar file to be opened for reading
verify – whether or not to verify the jar file if
it is signed.
mode – the mode in which the file is to be opened
Throws:
IOException – if an I/O error has occurred
IllegalArgumentException – 
        if the mode argument is invalid
SecurityException – if access to the file is denied
        by the SecurityManager
Since:
1.3/**
     * Creates a new <code>JarFile</code> to read from the specified
     * <code>File</code> object in the specified mode.  The mode argument
     * must be either <tt>OPEN_READ</tt> or <tt>OPEN_READ | OPEN_DELETE</tt>.
     *
     * @param file the jar file to be opened for reading
     * @param verify whether or not to verify the jar file if
     * it is signed.
     * @param mode the mode in which the file is to be opened
     * @throws IOException if an I/O error has occurred
     * @throws IllegalArgumentException
     *         if the <tt>mode</tt> argument is invalid
     * @throws SecurityException if access to the file is denied
     *         by the SecurityManager
     * @since 1.3
     */
    public JarFile(File file, boolean verify, int mode) throws IOException {
        super(file, mode);
        this.verify = verify;
    }

    
Returns the jar file manifest, or null if none.
Throws:
IllegalStateException – 
        may be thrown if the jar file has been closed
IOException –  if an I/O error has occurred
Returns:
the jar file manifest, or null if none/**
     * Returns the jar file manifest, or <code>null</code> if none.
     *
     * @return the jar file manifest, or <code>null</code> if none
     *
     * @throws IllegalStateException
     *         may be thrown if the jar file has been closed
     * @throws IOException  if an I/O error has occurred
     */
    public Manifest getManifest() throws IOException {
        return getManifestFromReference();
    }

    private Manifest getManifestFromReference() throws IOException {
        Manifest man = manRef != null ? manRef.get() : null;

        if (man == null) {

            JarEntry manEntry = getManEntry();

            // If found then load the manifest
            if (manEntry != null) {
                if (verify) {
                    byte[] b = getBytes(manEntry);
                    if (!jvInitialized) {
                        jv = new JarVerifier(b);
                    }
                    man = new Manifest(jv, new ByteArrayInputStream(b));
                } else {
                    man = new Manifest(super.getInputStream(manEntry));
                }
                manRef = new SoftReference<>(man);
            }
        }
        return man;
    }

    private native String[] getMetaInfEntryNames();

    
Returns the JarEntry for the given entry name or
null if not found.
Params:
name – the jar file entry name
Throws:
IllegalStateException – 
        may be thrown if the jar file has been closed
See Also:
JarEntry
Returns:
the JarEntry for the given entry name or
        null if not found./**
     * Returns the <code>JarEntry</code> for the given entry name or
     * <code>null</code> if not found.
     *
     * @param name the jar file entry name
     * @return the <code>JarEntry</code> for the given entry name or
     *         <code>null</code> if not found.
     *
     * @throws IllegalStateException
     *         may be thrown if the jar file has been closed
     *
     * @see java.util.jar.JarEntry
     */
    public JarEntry getJarEntry(String name) {
        return (JarEntry)getEntry(name);
    }

    
Returns the ZipEntry for the given entry name or
null if not found.
Params:
name – the jar file entry name
Throws:
IllegalStateException – 
        may be thrown if the jar file has been closed
See Also:
ZipEntry
Returns:
the ZipEntry for the given entry name or
        null if not found/**
     * Returns the <code>ZipEntry</code> for the given entry name or
     * <code>null</code> if not found.
     *
     * @param name the jar file entry name
     * @return the <code>ZipEntry</code> for the given entry name or
     *         <code>null</code> if not found
     *
     * @throws IllegalStateException
     *         may be thrown if the jar file has been closed
     *
     * @see java.util.zip.ZipEntry
     */
    public ZipEntry getEntry(String name) {
        ZipEntry ze = super.getEntry(name);
        if (ze != null) {
            return new JarFileEntry(ze);
        }
        return null;
    }

    private class JarEntryIterator implements Enumeration<JarEntry>,
            Iterator<JarEntry>
    {
        final Enumeration<? extends ZipEntry> e = JarFile.super.entries();

        public boolean hasNext() {
            return e.hasMoreElements();
        }

        public JarEntry next() {
            ZipEntry ze = e.nextElement();
            return new JarFileEntry(ze);
        }

        public boolean hasMoreElements() {
            return hasNext();
        }

        public JarEntry nextElement() {
            return next();
        }
    }

    
Returns an enumeration of the zip file entries.
/**
     * Returns an enumeration of the zip file entries.
     */
    public Enumeration<JarEntry> entries() {
        return new JarEntryIterator();
    }

    @Override
    public Stream<JarEntry> stream() {
        return StreamSupport.stream(Spliterators.spliterator(
                new JarEntryIterator(), size(),
                Spliterator.ORDERED | Spliterator.DISTINCT |
                        Spliterator.IMMUTABLE | Spliterator.NONNULL), false);
    }

    private class JarFileEntry extends JarEntry {
        JarFileEntry(ZipEntry ze) {
            super(ze);
        }
        public Attributes getAttributes() throws IOException {
            Manifest man = JarFile.this.getManifest();
            if (man != null) {
                return man.getAttributes(getName());
            } else {
                return null;
            }
        }
        public Certificate[] getCertificates() {
            try {
                maybeInstantiateVerifier();
            } catch (IOException e) {
                throw new RuntimeException(e);
            }
            if (certs == null && jv != null) {
                certs = jv.getCerts(JarFile.this, this);
            }
            return certs == null ? null : certs.clone();
        }
        public CodeSigner[] getCodeSigners() {
            try {
                maybeInstantiateVerifier();
            } catch (IOException e) {
                throw new RuntimeException(e);
            }
            if (signers == null && jv != null) {
                signers = jv.getCodeSigners(JarFile.this, this);
            }
            return signers == null ? null : signers.clone();
        }
    }

    /*
     * Ensures that the JarVerifier has been created if one is
     * necessary (i.e., the jar appears to be signed.) This is done as
     * a quick check to avoid processing of the manifest for unsigned
     * jars.
     */
    private void maybeInstantiateVerifier() throws IOException {
        if (jv != null) {
            return;
        }

        if (verify) {
            String[] names = getMetaInfEntryNames();
            if (names != null) {
                for (int i = 0; i < names.length; i++) {
                    String name = names[i].toUpperCase(Locale.ENGLISH);
                    if (name.endsWith(".DSA") ||
                        name.endsWith(".RSA") ||
                        name.endsWith(".EC") ||
                        name.endsWith(".SF")) {
                        // Assume since we found a signature-related file
                        // that the jar is signed and that we therefore
                        // need a JarVerifier and Manifest
                        getManifest();
                        return;
                    }
                }
            }
            // No signature-related files; don't instantiate a
            // verifier
            verify = false;
        }
    }


    /*
     * Initializes the verifier object by reading all the manifest
     * entries and passing them to the verifier.
     */
    private void initializeVerifier() {
        ManifestEntryVerifier mev = null;

        // Verify "META-INF/" entries...
        try {
            String[] names = getMetaInfEntryNames();
            if (names != null) {
                for (int i = 0; i < names.length; i++) {
                    String uname = names[i].toUpperCase(Locale.ENGLISH);
                    if (MANIFEST_NAME.equals(uname)
                            || SignatureFileVerifier.isBlockOrSF(uname)) {
                        JarEntry e = getJarEntry(names[i]);
                        if (e == null) {
                            throw new JarException("corrupted jar file");
                        }
                        if (mev == null) {
                            mev = new ManifestEntryVerifier
                                (getManifestFromReference());
                        }
                        byte[] b = getBytes(e);
                        if (b != null && b.length > 0) {
                            jv.beginEntry(e, mev);
                            jv.update(b.length, b, 0, b.length, mev);
                            jv.update(-1, null, 0, 0, mev);
                        }
                    }
                }
            }
        } catch (IOException ex) {
            // if we had an error parsing any blocks, just
            // treat the jar file as being unsigned
            jv = null;
            verify = false;
            if (JarVerifier.debug != null) {
                JarVerifier.debug.println("jarfile parsing error!");
                ex.printStackTrace();
            }
        }

        // if after initializing the verifier we have nothing
        // signed, we null it out.

        if (jv != null) {

            jv.doneWithMeta();
            if (JarVerifier.debug != null) {
                JarVerifier.debug.println("done with meta!");
            }

            if (jv.nothingToVerify()) {
                if (JarVerifier.debug != null) {
                    JarVerifier.debug.println("nothing to verify!");
                }
                jv = null;
                verify = false;
            }
        }
    }

    /*
     * Reads all the bytes for a given entry. Used to process the
     * META-INF files.
     */
    private byte[] getBytes(ZipEntry ze) throws IOException {
        try (InputStream is = super.getInputStream(ze)) {
            int len = (int)ze.getSize();
            byte[] b = IOUtils.readAllBytes(is);
            if (len != -1 && b.length != len)
                throw new EOFException("Expected:" + len + ", read:" + b.length);

            return b;
        }
    }

    
Returns an input stream for reading the contents of the specified
zip file entry.
Params:
ze – the zip file entry
Throws:
ZipException – if a zip file format error has occurred
IOException – if an I/O error has occurred
SecurityException – if any of the jar file entries
        are incorrectly signed.
IllegalStateException – 
        may be thrown if the jar file has been closed
Returns:
an input stream for reading the contents of the specified
        zip file entry/**
     * Returns an input stream for reading the contents of the specified
     * zip file entry.
     * @param ze the zip file entry
     * @return an input stream for reading the contents of the specified
     *         zip file entry
     * @throws ZipException if a zip file format error has occurred
     * @throws IOException if an I/O error has occurred
     * @throws SecurityException if any of the jar file entries
     *         are incorrectly signed.
     * @throws IllegalStateException
     *         may be thrown if the jar file has been closed
     */
    public synchronized InputStream getInputStream(ZipEntry ze)
        throws IOException
    {
        maybeInstantiateVerifier();
        if (jv == null) {
            return super.getInputStream(ze);
        }
        if (!jvInitialized) {
            initializeVerifier();
            jvInitialized = true;
            // could be set to null after a call to
            // initializeVerifier if we have nothing to
            // verify
            if (jv == null)
                return super.getInputStream(ze);
        }

        // wrap a verifier stream around the real stream
        return new JarVerifier.VerifierStream(
            getManifestFromReference(),
            ze instanceof JarFileEntry ?
            (JarEntry) ze : getJarEntry(ze.getName()),
            super.getInputStream(ze),
            jv);
    }

    // Statics for hand-coded Boyer-Moore search
    private static final char[] CLASSPATH_CHARS = {'c','l','a','s','s','-','p','a','t','h'};
    // The bad character shift for "class-path"
    private static final int[] CLASSPATH_LASTOCC;
    // The good suffix shift for "class-path"
    private static final int[] CLASSPATH_OPTOSFT;

    static {
        CLASSPATH_LASTOCC = new int[128];
        CLASSPATH_OPTOSFT = new int[10];
        CLASSPATH_LASTOCC[(int)'c'] = 1;
        CLASSPATH_LASTOCC[(int)'l'] = 2;
        CLASSPATH_LASTOCC[(int)'s'] = 5;
        CLASSPATH_LASTOCC[(int)'-'] = 6;
        CLASSPATH_LASTOCC[(int)'p'] = 7;
        CLASSPATH_LASTOCC[(int)'a'] = 8;
        CLASSPATH_LASTOCC[(int)'t'] = 9;
        CLASSPATH_LASTOCC[(int)'h'] = 10;
        for (int i=0; i<9; i++)
            CLASSPATH_OPTOSFT[i] = 10;
        CLASSPATH_OPTOSFT[9]=1;
    }

    private JarEntry getManEntry() {
        if (manEntry == null) {
            // First look up manifest entry using standard name
            manEntry = getJarEntry(MANIFEST_NAME);
            if (manEntry == null) {
                // If not found, then iterate through all the "META-INF/"
                // entries to find a match.
                String[] names = getMetaInfEntryNames();
                if (names != null) {
                    for (int i = 0; i < names.length; i++) {
                        if (MANIFEST_NAME.equals(
                                                 names[i].toUpperCase(Locale.ENGLISH))) {
                            manEntry = getJarEntry(names[i]);
                            break;
                        }
                    }
                }
            }
        }
        return manEntry;
    }

   
Returns true iff this JAR file has a manifest with the Class-Path attribute /**
    * Returns {@code true} iff this JAR file has a manifest with the
    * Class-Path attribute
    */
    boolean hasClassPathAttribute() throws IOException {
        checkForSpecialAttributes();
        return hasClassPathAttribute;
    }

    
Returns true if the pattern src is found in b. The lastOcc and optoSft arrays are the precomputed bad character and good suffix shifts. /**
     * Returns true if the pattern {@code src} is found in {@code b}.
     * The {@code lastOcc} and {@code optoSft} arrays are the precomputed
     * bad character and good suffix shifts.
     */
    private boolean match(char[] src, byte[] b, int[] lastOcc, int[] optoSft) {
        int len = src.length;
        int last = b.length - len;
        int i = 0;
        next:
        while (i<=last) {
            for (int j=(len-1); j>=0; j--) {
                char c = (char) b[i+j];
                c = (((c-'A')|('Z'-c)) >= 0) ? (char)(c + 32) : c;
                if (c != src[j]) {
                    i += Math.max(j + 1 - lastOcc[c&0x7F], optoSft[j]);
                    continue next;
                 }
            }
            return true;
        }
        return false;
    }

    
On first invocation, check if the JAR file has the Class-Path
attribute. A no-op on subsequent calls.
/**
     * On first invocation, check if the JAR file has the Class-Path
     * attribute. A no-op on subsequent calls.
     */
    private void checkForSpecialAttributes() throws IOException {
        if (hasCheckedSpecialAttributes) return;
        if (!isKnownNotToHaveSpecialAttributes()) {
            JarEntry manEntry = getManEntry();
            if (manEntry != null) {
                byte[] b = getBytes(manEntry);
                if (match(CLASSPATH_CHARS, b, CLASSPATH_LASTOCC, CLASSPATH_OPTOSFT))
                    hasClassPathAttribute = true;
            }
        }
        hasCheckedSpecialAttributes = true;
    }

    private static String javaHome;
    private static volatile String[] jarNames;
    private boolean isKnownNotToHaveSpecialAttributes() {
        // Optimize away even scanning of manifest for jar files we
        // deliver which don't have a class-path attribute. If one of
        // these jars is changed to include such an attribute this code
        // must be changed.
        if (javaHome == null) {
            javaHome = AccessController.doPrivileged(
                new GetPropertyAction("java.home"));
        }
        if (jarNames == null) {
            String[] names = new String[11];
            String fileSep = File.separator;
            int i = 0;
            names[i++] = fileSep + "rt.jar";
            names[i++] = fileSep + "jsse.jar";
            names[i++] = fileSep + "jce.jar";
            names[i++] = fileSep + "charsets.jar";
            names[i++] = fileSep + "dnsns.jar";
            names[i++] = fileSep + "zipfs.jar";
            names[i++] = fileSep + "localedata.jar";
            names[i++] = fileSep = "cldrdata.jar";
            names[i++] = fileSep + "sunjce_provider.jar";
            names[i++] = fileSep + "sunpkcs11.jar";
            names[i++] = fileSep + "sunec.jar";
            jarNames = names;
        }

        String name = getName();
        String localJavaHome = javaHome;
        if (name.startsWith(localJavaHome)) {
            String[] names = jarNames;
            for (int i = 0; i < names.length; i++) {
                if (name.endsWith(names[i])) {
                    return true;
                }
            }
        }
        return false;
    }

    synchronized void ensureInitialization() {
        try {
            maybeInstantiateVerifier();
        } catch (IOException e) {
            throw new RuntimeException(e);
        }
        if (jv != null && !jvInitialized) {
            initializeVerifier();
            jvInitialized = true;
        }
    }

    JarEntry newEntry(ZipEntry ze) {
        return new JarFileEntry(ze);
    }

    Enumeration<String> entryNames(CodeSource[] cs) {
        ensureInitialization();
        if (jv != null) {
            return jv.entryNames(this, cs);
        }

        /*
         * JAR file has no signed content. Is there a non-signing
         * code source?
         */
        boolean includeUnsigned = false;
        for (int i = 0; i < cs.length; i++) {
            if (cs[i].getCodeSigners() == null) {
                includeUnsigned = true;
                break;
            }
        }
        if (includeUnsigned) {
            return unsignedEntryNames();
        } else {
            return new Enumeration<String>() {

                public boolean hasMoreElements() {
                    return false;
                }

                public String nextElement() {
                    throw new NoSuchElementException();
                }
            };
        }
    }

    
Returns an enumeration of the zip file entries
excluding internal JAR mechanism entries and including
signed entries missing from the ZIP directory.
/**
     * Returns an enumeration of the zip file entries
     * excluding internal JAR mechanism entries and including
     * signed entries missing from the ZIP directory.
     */
    Enumeration<JarEntry> entries2() {
        ensureInitialization();
        if (jv != null) {
            return jv.entries2(this, super.entries());
        }

        // screen out entries which are never signed
        final Enumeration<? extends ZipEntry> enum_ = super.entries();
        return new Enumeration<JarEntry>() {

            ZipEntry entry;

            public boolean hasMoreElements() {
                if (entry != null) {
                    return true;
                }
                while (enum_.hasMoreElements()) {
                    ZipEntry ze = enum_.nextElement();
                    if (JarVerifier.isSigningRelated(ze.getName())) {
                        continue;
                    }
                    entry = ze;
                    return true;
                }
                return false;
            }

            public JarFileEntry nextElement() {
                if (hasMoreElements()) {
                    ZipEntry ze = entry;
                    entry = null;
                    return new JarFileEntry(ze);
                }
                throw new NoSuchElementException();
            }
        };
    }

    CodeSource[] getCodeSources(URL url) {
        ensureInitialization();
        if (jv != null) {
            return jv.getCodeSources(this, url);
        }

        /*
         * JAR file has no signed content. Is there a non-signing
         * code source?
         */
        Enumeration<String> unsigned = unsignedEntryNames();
        if (unsigned.hasMoreElements()) {
            return new CodeSource[]{JarVerifier.getUnsignedCS(url)};
        } else {
            return null;
        }
    }

    private Enumeration<String> unsignedEntryNames() {
        final Enumeration<JarEntry> entries = entries();
        return new Enumeration<String>() {

            String name;

            /*
             * Grab entries from ZIP directory but screen out
             * metadata.
             */
            public boolean hasMoreElements() {
                if (name != null) {
                    return true;
                }
                while (entries.hasMoreElements()) {
                    String value;
                    ZipEntry e = entries.nextElement();
                    value = e.getName();
                    if (e.isDirectory() || JarVerifier.isSigningRelated(value)) {
                        continue;
                    }
                    name = value;
                    return true;
                }
                return false;
            }

            public String nextElement() {
                if (hasMoreElements()) {
                    String value = name;
                    name = null;
                    return value;
                }
                throw new NoSuchElementException();
            }
        };
    }

    CodeSource getCodeSource(URL url, String name) {
        ensureInitialization();
        if (jv != null) {
            if (jv.eagerValidation) {
                CodeSource cs = null;
                JarEntry je = getJarEntry(name);
                if (je != null) {
                    cs = jv.getCodeSource(url, this, je);
                } else {
                    cs = jv.getCodeSource(url, name);
                }
                return cs;
            } else {
                return jv.getCodeSource(url, name);
            }
        }

        return JarVerifier.getUnsignedCS(url);
    }

    void setEagerValidation(boolean eager) {
        try {
            maybeInstantiateVerifier();
        } catch (IOException e) {
            throw new RuntimeException(e);
        }
        if (jv != null) {
            jv.setEagerValidation(eager);
        }
    }

    List<Object> getManifestDigests() {
        ensureInitialization();
        if (jv != null) {
            return jv.getManifestDigests();
        }
        return new ArrayList<Object>();
    }
}