content: /*
   * Licensed to the Apache Software Foundation (ASF) under one or more
   * contributor license agreements.  See the NOTICE file distributed with
   * this work for additional information regarding copyright ownership.
   * The ASF licenses this file to You under the Apache License, Version 2.0
   * (the "License"); you may not use this file except in compliance with
   * the License.  You may obtain a copy of the License at
   *
   *     http://www.apache.org/licenses/LICENSE-2.0
   *
   * Unless required by applicable law or agreed to in writing, software
   * distributed under the License is distributed on an "AS IS" BASIS,
   * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
   * See the License for the specific language governing permissions and
   * limitations under the License.
   */
  
  package android.framework.util.jar;
  
  import java.io.IOException;
  import java.security.CodeSigner;
  import java.security.cert.CertPath;
  import java.security.cert.Certificate;
  import java.security.cert.CertificateException;
  import java.security.cert.CertificateFactory;
  import java.security.cert.X509Certificate;
  import java.util.ArrayList;
  import java.util.List;
  import java.util.zip.ZipEntry;
  import javax.security.auth.x500.X500Principal;
  
  /**
   * Represents a single file in a JAR archive together with the manifest
   * attributes and digital signatures associated with it.
   *
   * @see JarFile
   * @see JarInputStream
   */
  public class JarEntry extends ZipEntry {
      private Attributes attributes;
  
      JarFile parentJar;
  
      CodeSigner signers[];
  
      // Cached factory used to build CertPath-s in <code>getCodeSigners()</code>.
      private CertificateFactory factory;
  
      private boolean isFactoryChecked = false;
  
      /**
       * Creates a new {@code JarEntry} named name.
       *
       * @param name
       *            The name of the new {@code JarEntry}.
       */
      public JarEntry(String name) {
          super(name);
      }
  
      /**
       * Creates a new {@code JarEntry} using the values obtained from entry.
       *
       * @param entry
       *            The ZipEntry to obtain values from.
       */
      public JarEntry(ZipEntry entry) {
          super(entry);
      }
  
      /**
       * Returns the {@code Attributes} object associated with this entry or
       * {@code null} if none exists.
       *
       * @return the {@code Attributes} for this entry.
       * @exception IOException
       *                If an error occurs obtaining the {@code Attributes}.
       * @see Attributes
       */
      public Attributes getAttributes() throws IOException {
          if (attributes != null || parentJar == null) {
              return attributes;
          }
          Manifest manifest = parentJar.getManifest();
          if (manifest == null) {
              return null;
          }
          return attributes = manifest.getAttributes(getName());
      }
  
      /**
       * Returns an array of {@code Certificate} Objects associated with this
       * entry or {@code null} if none exists. Make sure that the everything is
       * read from the input stream before calling this method, or else the method
       * returns {@code null}.
       *
       * @return the certificate for this entry.
       * @see java.security.cert.Certificate
       */
      public Certificate[] getCertificates() {
          if (parentJar == null) {
              return null;
          }
          JarVerifier jarVerifier = parentJar.verifier;
          if (jarVerifier == null) {
              return null;
          }
          return jarVerifier.getCertificates(getName());
      }
  
      void setAttributes(Attributes attrib) {
          attributes = attrib;
      }
  
      /**
       * Create a new {@code JarEntry} using the values obtained from the
       * argument.
       *
       * @param je
       *            The {@code JarEntry} to obtain values from.
       */
      public JarEntry(JarEntry je) {
          super(je);
          parentJar = je.parentJar;
          attributes = je.attributes;
          signers = je.signers;
      }
  
      /**
       * Returns the code signers for the digital signatures associated with the
       * JAR file. If there is no such code signer, it returns {@code null}. Make
       * sure that the everything is read from the input stream before calling
       * this method, or else the method returns {@code null}.
       *
       * @return the code signers for the JAR entry.
       * @see CodeSigner
       */
      public CodeSigner[] getCodeSigners() {
          if (signers == null) {
              signers = getCodeSigners(getCertificates());
          }
          if (signers == null) {
              return null;
          }
  
          CodeSigner[] tmp = new CodeSigner[signers.length];
          System.arraycopy(signers, 0, tmp, 0, tmp.length);
          return tmp;
      }
  
      private CodeSigner[] getCodeSigners(Certificate[] certs) {
          if (certs == null) {
              return null;
          }
  
          X500Principal prevIssuer = null;
          ArrayList<Certificate> list = new ArrayList<Certificate>(certs.length);
          ArrayList<CodeSigner> asigners = new ArrayList<CodeSigner>();
  
          for (Certificate element : certs) {
              if (!(element instanceof X509Certificate)) {
                  // Only X509Certificate-s are taken into account - see API spec.
                  continue;
              }
              X509Certificate x509 = (X509Certificate) element;
              if (prevIssuer != null) {
                  X500Principal subj = x509.getSubjectX500Principal();
                  if (!prevIssuer.equals(subj)) {
                      // Ok, this ends the previous chain,
                      // so transform this one into CertPath ...
                      addCodeSigner(asigners, list);
                      // ... and start a new one
                      list.clear();
                  }// else { it's still the same chain }
  
              }
              prevIssuer = x509.getIssuerX500Principal();
              list.add(x509);
          }
          if (!list.isEmpty()) {
              addCodeSigner(asigners, list);
          }
          if (asigners.isEmpty()) {
              // 'signers' is 'null' already
              return null;
          }
  
          CodeSigner[] tmp = new CodeSigner[asigners.size()];
          asigners.toArray(tmp);
          return tmp;
  
      }
  
      private void addCodeSigner(ArrayList<CodeSigner> asigners,
              List<Certificate> list) {
          CertPath certPath = null;
          if (!isFactoryChecked) {
              try {
                  factory = CertificateFactory.getInstance("X.509");
              } catch (CertificateException ex) {
                  // do nothing
              } finally {
                  isFactoryChecked = true;
              }
          }
          if (factory == null) {
              return;
          }
          try {
              certPath = factory.generateCertPath(list);
          } catch (CertificateException ex) {
              // do nothing
          }
          if (certPath != null) {
              asigners.add(new CodeSigner(certPath, null));
          }
      }
  }
  