JarInputStream


1   /*
2    * @(#)JarInputStream.java  1.35 05/05/27
3    *
4    * Copyright 2005 Sun Microsystems, Inc. All rights reserved.
5    * SUN PROPRIETARY/CONFIDENTIAL. Use is subject to license terms.
6    */
7   
8   package java.util.jar;
9   
10  import java.util.zip.*;
11  import java.io.*;
12  import sun.security.util.ManifestEntryVerifier;
13  
14  /**
15   * The <code>JarInputStream</code> class is used to read the contents of
16   * a JAR file from any input stream. It extends the class
17   * <code>java.util.zip.ZipInputStream</code> with support for reading
18   * an optional <code>Manifest</code> entry. The <code>Manifest</code>
19   * can be used to store meta-information about the JAR file and its entries.
20   *
21   * @author  David Connelly
22   * @version 1.35, 05/27/05
23   * @see     Manifest
24   * @see     java.util.zip.ZipInputStream
25   * @since   1.2
26   */
27  public
28  class JarInputStream extends ZipInputStream {
29      private Manifest   man;
30      private JarEntry   first;
31      private JarVerifier   jv;
32      private ManifestEntryVerifier mev;
33  
34  
35      /**
36       * Creates a new <code>JarInputStream</code> and reads the optional
37       * manifest. If a manifest is present, also attempts to verify
38       * the signatures if the JarInputStream is signed.
39       * @param in the actual input stream
40       * @exception IOException if an I/O error has occurred
41       */
42      public JarInputStream(InputStream in) throws IOException {
43      this(in, true);
44      }
45  
46      /**
47       * Creates a new <code>JarInputStream</code> and reads the optional
48       * manifest. If a manifest is present and verify is true, also attempts 
49       * to verify the signatures if the JarInputStream is signed.
50       *
51       * @param in the actual input stream
52       * @param verify whether or not to verify the JarInputStream if
53       * it is signed.
54       * @exception IOException if an I/O error has occurred
55       */
56      public JarInputStream(InputStream in, boolean verify) throws IOException {
57      super(in);
58      JarEntry   e = (JarEntry  )super.getNextEntry();
59  
60          if (e != null && e.getName().equalsIgnoreCase("META-INF/"))
61              e = (JarEntry  )super.getNextEntry();
62  
63          if (e != null && JarFile.MANIFEST_NAME.equalsIgnoreCase(e.getName())) {
64              man = new Manifest  ();
65              byte bytes[] = getBytes(new BufferedInputStream(this));
66              man.read(new ByteArrayInputStream(bytes));
67              //man.read(new BufferedInputStream(this));
68              closeEntry();
69              if (verify) {
70                  jv = new JarVerifier  (bytes);
71                  mev = new ManifestEntryVerifier(man);
72              }
73              first = getNextJarEntry();
74          } else {
75              first = e;
76          }
77      }
78  
79      private byte[] getBytes(InputStream is)
80      throws IOException
81      {
82      byte[] buffer = new byte[8192];
83      ByteArrayOutputStream baos = new ByteArrayOutputStream(2048);
84  
85      int n;
86  
87      baos.reset();
88      while ((n = is.read(buffer, 0, buffer.length)) != -1) {
89          baos.write(buffer, 0, n);
90      }
91      return baos.toByteArray();
92      }
93  
94      /**
95       * Returns the <code>Manifest</code> for this JAR file, or
96       * <code>null</code> if none.
97       *
98       * @return the <code>Manifest</code> for this JAR file, or
99       *         <code>null</code> if none.
100      */
101     public Manifest   getManifest() {
102     return man;
103     }
104 
105     /**
106      * Reads the next ZIP file entry and positions the stream at the
107      * beginning of the entry data. If verification has been enabled,
108      * any invalid signature detected while positioning the stream for
109      * the next entry will result in an exception.
110      * @exception ZipException if a ZIP file error has occurred
111      * @exception IOException if an I/O error has occurred
112      * @exception SecurityException if any of the jar file entries
113      *         are incorrectly signed.
114      */
115     public ZipEntry getNextEntry() throws IOException {
116     JarEntry   e;
117     if (first == null) {
118         e = (JarEntry  )super.getNextEntry();
119     } else {
120         e = first;
121         first = null;
122     }
123     if (jv != null && e != null) {
124         // At this point, we might have parsed all the meta-inf
125         // entries and have nothing to verify. If we have
126         // nothing to verify, get rid of the JarVerifier object.
127         if (jv.nothingToVerify() == true) {
128         jv = null;
129         mev = null;
130         } else {
131         jv.beginEntry(e, mev);
132         }
133     }
134     return e;
135     }
136 
137     /**
138      * Reads the next JAR file entry and positions the stream at the
139      * beginning of the entry data. If verification has been enabled,
140      * any invalid signature detected while positioning the stream for
141      * the next entry will result in an exception.
142      * @return the next JAR file entry, or null if there are no more entries
143      * @exception ZipException if a ZIP file error has occurred
144      * @exception IOException if an I/O error has occurred
145      * @exception SecurityException if any of the jar file entries
146      *         are incorrectly signed.
147      */
148     public JarEntry   getNextJarEntry() throws IOException {
149     return (JarEntry  )getNextEntry();
150     }
151 
152     /**
153      * Reads from the current JAR file entry into an array of bytes.
154      * Blocks until some input is available.
155      * If verification has been enabled, any invalid signature
156      * on the current entry will be reported at some point before the
157      * end of the entry is reached.
158      * @param b the buffer into which the data is read
159      * @param off the start offset of the data
160      * @param len the maximum number of bytes to read
161      * @return the actual number of bytes read, or -1 if the end of the
162      *         entry is reached
163      * @exception ZipException if a ZIP file error has occurred
164      * @exception IOException if an I/O error has occurred
165      * @exception SecurityException if any of the jar file entries
166      *         are incorrectly signed.
167      */
168     public int read(byte[] b, int off, int len) throws IOException {
169     int n;
170     if (first == null) {
171         n = super.read(b, off, len);
172     } else {
173         n = -1;
174     }
175     if (jv != null) {
176         jv.update(n, b, off, len, mev);
177     }
178     return n;
179     }
180 
181     /**
182      * Creates a new <code>JarEntry</code> (<code>ZipEntry</code>) for the
183      * specified JAR file entry name. The manifest attributes of
184      * the specified JAR file entry name will be copied to the new 
185      * <CODE>JarEntry</CODE>.
186      *
187      * @param name the name of the JAR/ZIP file entry
188      * @return the <code>JarEntry</code> object just created
189      */
190     protected ZipEntry createZipEntry(String   name) {
191     JarEntry   e = new JarEntry  (name);
192     if (man != null) {
193         e.attr = man.getAttributes(name);
194     }
195     return e;
196     }
197 }
198
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