1 /*
2 * Copyright (c) 1996, 2015, Oracle and/or its affiliates. All rights reserved.
3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
4 *
5 * This code is free software; you can redistribute it and/or modify it
6 * under the terms of the GNU General Public License version 2 only, as
7 * published by the Free Software Foundation. Oracle designates this
8 * particular file as subject to the "Classpath" exception as provided
9 * by Oracle in the LICENSE file that accompanied this code.
10 *
11 * This code is distributed in the hope that it will be useful, but WITHOUT
12 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
13 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
14 * version 2 for more details (a copy is included in the LICENSE file that
15 * accompanied this code).
16 *
17 * You should have received a copy of the GNU General Public License version
18 * 2 along with this work; if not, write to the Free Software Foundation,
19 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
20 *
21 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
22 * or visit www.oracle.com if you need additional information or have any
23 * questions.
24 */
25
26 package java.util.zip;
27
28 import java.io.InputStream;
29 import java.io.IOException;
30 import java.io.EOFException;
31 import java.io.PushbackInputStream;
32 import java.nio.charset.Charset;
33 import java.nio.charset.StandardCharsets;
34 import static java.util.zip.ZipConstants64.*;
35 import static java.util.zip.ZipUtils.*;
36
37 /**
38 * This class implements an input stream filter for reading files in the
39 * ZIP file format. Includes support for both compressed and uncompressed
40 * entries.
41 *
42 * @author David Connelly
43 */
44 public
45 class ZipInputStream extends InflaterInputStream implements ZipConstants {
46 private ZipEntry entry;
47 private int flag;
48 private CRC32 crc = new CRC32();
49 private long remaining;
50 private byte[] tmpbuf = new byte[512];
51
52 private static final int STORED = ZipEntry.STORED;
53 private static final int DEFLATED = ZipEntry.DEFLATED;
54
55 private boolean closed = false;
56 // this flag is set to true after EOF has reached for
57 // one entry
58 private boolean entryEOF = false;
59
60 private ZipCoder zc;
61
62 private ZipCryption zipCryption;
63
64 /**
65 * Check to make sure that this stream has not been closed
66 */
67 private void ensureOpen() throws IOException {
68 if (closed) {
69 throw new IOException("Stream closed");
70 }
71 }
72
73 /**
74 * Creates a new ZIP input stream.
75 *
76 * <p>The UTF-8 {@link java.nio.charset.Charset charset} is used to
77 * decode the entry names.
78 *
79 * @param in the actual input stream
80 */
81 public ZipInputStream(InputStream in) {
82 this(in, StandardCharsets.UTF_8);
83 }
84
85 /**
86 * Creates a new ZIP input stream.
87 *
88 * @param in the actual input stream
89 *
90 * @param charset
91 * The {@linkplain java.nio.charset.Charset charset} to be
92 * used to decode the ZIP entry name (ignored if the
93 * <a href="package-summary.html#lang_encoding"> language
94 * encoding bit</a> of the ZIP entry's general purpose bit
95 * flag is set).
96 *
97 * @since 1.7
98 */
99 public ZipInputStream(InputStream in, Charset charset) {
100 super(new PushbackInputStream(in, 512), new Inflater(true), 512);
101 usesDefaultInflater = true;
102 if(in == null) {
103 throw new NullPointerException("in is null");
104 }
105 if (charset == null)
106 throw new NullPointerException("charset is null");
107 this.zc = ZipCoder.get(charset);
108 }
109
110 /**
111 * Reads the next ZIP file entry and positions the stream at the
112 * beginning of the entry data.
113 * @return the next ZIP file entry, or null if there are no more entries
114 * @exception ZipException if a ZIP file error has occurred
115 * @exception IOException if an I/O error has occurred
116 * @since 1.9
117 */
118 public ZipEntry getNextEntry() throws IOException {
119 return getNextEntry(null);
120 }
121
122 /**
123 * Reads the next ZIP file entry and positions the stream at the
124 * beginning of the entry data.
125 * @param zipCryption ZIP encrypt/decrypt engine. zip decryption will not
126 * work if this value set to null.
127 * @return the next ZIP file entry, or null if there are no more entries
128 * @exception ZipException if a ZIP file error has occurred
129 * @exception IOException if an I/O error has occurred
130 */
131 public ZipEntry getNextEntry(ZipCryption zipCryption) throws IOException {
132 ensureOpen();
133 if (entry != null) {
134 closeEntry();
135 }
136 crc.reset();
137 inf.reset();
138 if ((entry = readLOC(zipCryption)) == null) {
139 return null;
140 }
141 if (entry.method == STORED) {
142 remaining = entry.size;
143 }
144 entryEOF = false;
145 return entry;
146 }
147
148 /**
149 * Closes the current ZIP entry and positions the stream for reading the
150 * next entry.
151 * @exception ZipException if a ZIP file error has occurred
152 * @exception IOException if an I/O error has occurred
153 */
154 public void closeEntry() throws IOException {
155 ensureOpen();
156 while (read(tmpbuf, 0, tmpbuf.length) != -1) ;
157 entryEOF = true;
158 }
159
160 /**
161 * Returns 0 after EOF has reached for the current entry data,
162 * otherwise always return 1.
163 * <p>
164 * Programs should not count on this method to return the actual number
165 * of bytes that could be read without blocking.
166 *
167 * @return 1 before EOF and 0 after EOF has reached for current entry.
168 * @exception IOException if an I/O error occurs.
169 *
170 */
171 public int available() throws IOException {
172 ensureOpen();
173 if (entryEOF) {
174 return 0;
175 } else {
176 return 1;
177 }
178 }
179
180 /**
181 * Reads from the current ZIP entry into an array of bytes.
182 * If <code>len</code> is not zero, the method
183 * blocks until some input is available; otherwise, no
184 * bytes are read and <code>0</code> is returned.
185 * @param b the buffer into which the data is read
186 * @param off the start offset in the destination array <code>b</code>
187 * @param len the maximum number of bytes read
188 * @return the actual number of bytes read, or -1 if the end of the
189 * entry is reached
190 * @exception NullPointerException if <code>b</code> is <code>null</code>.
191 * @exception IndexOutOfBoundsException if <code>off</code> is negative,
192 * <code>len</code> is negative, or <code>len</code> is greater than
193 * <code>b.length - off</code>
194 * @exception ZipException if a ZIP file error has occurred
195 * @exception IOException if an I/O error has occurred
196 */
197 public int read(byte[] b, int off, int len) throws IOException {
198 ensureOpen();
199 if (off < 0 || len < 0 || off > b.length - len) {
200 throw new IndexOutOfBoundsException();
201 } else if (len == 0) {
202 return 0;
203 }
204
205 if (entry == null) {
206 return -1;
207 }
208 switch (entry.method) {
209 case DEFLATED:
210 len = super.read(b, off, len);
211 if (len == -1) {
212 readEnd(entry);
213 entryEOF = true;
214 entry = null;
215 } else {
216 crc.update(b, off, len);
217 }
218 return len;
219 case STORED:
220 if (remaining <= 0) {
221 entryEOF = true;
222 entry = null;
223 return -1;
224 }
225 if (len > remaining) {
226 len = (int)remaining;
227 }
228 len = in.read(b, off, len);
229 if (len == -1) {
230 throw new ZipException("unexpected EOF");
231 }
232 if (zipCryption != null) {
233 zipCryption.decryptBytes(b, off, len);
234 }
235 crc.update(b, off, len);
236 remaining -= len;
237 if (remaining == 0 && entry.crc != crc.getValue()) {
238 throw new ZipException(
239 "invalid entry CRC (expected 0x" + Long.toHexString(entry.crc) +
240 " but got 0x" + Long.toHexString(crc.getValue()) + ")");
241 }
242 return len;
243 default:
244 throw new ZipException("invalid compression method");
245 }
246 }
247
248 /**
249 * Skips specified number of bytes in the current ZIP entry.
250 * @param n the number of bytes to skip
251 * @return the actual number of bytes skipped
252 * @exception ZipException if a ZIP file error has occurred
253 * @exception IOException if an I/O error has occurred
254 * @exception IllegalArgumentException if {@code n < 0}
255 */
256 public long skip(long n) throws IOException {
257 if (n < 0) {
258 throw new IllegalArgumentException("negative skip length");
259 }
260 ensureOpen();
261 int max = (int)Math.min(n, Integer.MAX_VALUE);
262 int total = 0;
263 while (total < max) {
264 int len = max - total;
265 if (len > tmpbuf.length) {
266 len = tmpbuf.length;
267 }
268 len = read(tmpbuf, 0, len);
269 if (len == -1) {
270 entryEOF = true;
271 break;
272 }
273 total += len;
274 }
275 return total;
276 }
277
278 /**
279 * Closes this input stream and releases any system resources associated
280 * with the stream.
281 * @exception IOException if an I/O error has occurred
282 */
283 public void close() throws IOException {
284 if (!closed) {
285 super.close();
286 closed = true;
287 }
288 }
289
290 private byte[] b = new byte[256];
291
292 /*
293 * Reads local file (LOC) header for next entry.
294 */
295 private ZipEntry readLOC(ZipCryption zipCryption) throws IOException {
296 this.zipCryption = zipCryption;
297
298 try {
299 readFully(tmpbuf, 0, LOCHDR);
300 } catch (EOFException e) {
301 return null;
302 }
303 if (get32(tmpbuf, 0) != LOCSIG) {
304 return null;
305 }
306 // get flag first, we need check EFS and encryption.
307 flag = get16(tmpbuf, LOCFLG);
308 // get the entry name and create the ZipEntry first
309 int len = get16(tmpbuf, LOCNAM);
310 int blen = b.length;
311 if (len > blen) {
312 do {
313 blen = blen * 2;
314 } while (len > blen);
315 b = new byte[blen];
316 }
317 readFully(b, 0, len);
318 // Force to use UTF-8 if the EFS bit is ON, even the cs is NOT UTF-8
319 ZipEntry e = createZipEntry(((flag & EFS) != 0)
320 ? zc.toStringUTF8(b, len)
321 : zc.toString(b, len));
322 e.flag = flag;
323 // now get the remaining fields for the entry
324 if (((flag & 1) == 1) && (zipCryption == null)) {
325 throw new ZipException("ZipCryption is required.");
326 }
327 e.method = get16(tmpbuf, LOCHOW);
328 e.xdostime = get32(tmpbuf, LOCTIM);
329 if ((flag & 8) == 8) {
330 /* "Data Descriptor" present */
331 if (e.method != DEFLATED) {
332 throw new ZipException(
333 "only DEFLATED entries can have EXT descriptor");
334 }
335 } else {
336 e.crc = get32(tmpbuf, LOCCRC);
337 e.csize = get32(tmpbuf, LOCSIZ);
338 e.size = get32(tmpbuf, LOCLEN);
339 }
340 len = get16(tmpbuf, LOCEXT);
341 if (len > 0) {
342 byte[] extra = new byte[len];
343 readFully(extra, 0, len);
344 e.setExtra0(extra,
345 e.csize == ZIP64_MAGICVAL || e.size == ZIP64_MAGICVAL);
346 }
347
348 if (zipCryption != null) {
349 zipCryption.reset();
350 super.setZipCryption(zipCryption);
351
352 byte[] encryptionHeader =
353 new byte[zipCryption.getEncryptionHeaderSize()];
354 readFully(encryptionHeader, 0, encryptionHeader.length);
355 zipCryption.decryptBytes(encryptionHeader);
356
357 if (!zipCryption.isValid(e, encryptionHeader)) {
358 throw new ZipException("possibly incorrect passphrase");
359 }
360
361 }
362
363 return e;
364 }
365
366 /**
367 * Creates a new <code>ZipEntry</code> object for the specified
368 * entry name.
369 *
370 * @param name the ZIP file entry name
371 * @return the ZipEntry just created
372 */
373 protected ZipEntry createZipEntry(String name) {
374 return new ZipEntry(name);
375 }
376
377 /**
378 * Reads end of deflated entry as well as EXT descriptor if present.
379 *
380 * Local headers for DEFLATED entries may optionally be followed by a
381 * data descriptor, and that data descriptor may optionally contain a
382 * leading signature (EXTSIG).
383 *
384 * From the zip spec http://www.pkware.com/documents/casestudies/APPNOTE.TXT
385 *
386 * """Although not originally assigned a signature, the value 0x08074b50
387 * has commonly been adopted as a signature value for the data descriptor
388 * record. Implementers should be aware that ZIP files may be
389 * encountered with or without this signature marking data descriptors
390 * and should account for either case when reading ZIP files to ensure
391 * compatibility."""
392 */
393 private void readEnd(ZipEntry e) throws IOException {
394 int n = inf.getRemaining();
395 if (n > 0) {
396 ((PushbackInputStream)in).unread(
397 (zipCryption == null) ? buf : originBuf, len - n, n);
398 }
399 if ((flag & 8) == 8) {
400 /* "Data Descriptor" present */
401 if (inf.getBytesWritten() > ZIP64_MAGICVAL ||
402 inf.getBytesRead() > ZIP64_MAGICVAL) {
403 // ZIP64 format
404 readFully(tmpbuf, 0, ZIP64_EXTHDR);
405 long sig = get32(tmpbuf, 0);
406 if (sig != EXTSIG) { // no EXTSIG present
407 e.crc = sig;
408 e.csize = get64(tmpbuf, ZIP64_EXTSIZ - ZIP64_EXTCRC);
409 e.size = get64(tmpbuf, ZIP64_EXTLEN - ZIP64_EXTCRC);
410 ((PushbackInputStream)in).unread(
411 tmpbuf, ZIP64_EXTHDR - ZIP64_EXTCRC, ZIP64_EXTCRC);
412 } else {
413 e.crc = get32(tmpbuf, ZIP64_EXTCRC);
414 e.csize = get64(tmpbuf, ZIP64_EXTSIZ);
415 e.size = get64(tmpbuf, ZIP64_EXTLEN);
416 }
417 } else {
418 readFully(tmpbuf, 0, EXTHDR);
419 long sig = get32(tmpbuf, 0);
420 if (sig != EXTSIG) { // no EXTSIG present
421 e.crc = sig;
422 e.csize = get32(tmpbuf, EXTSIZ - EXTCRC);
423 e.size = get32(tmpbuf, EXTLEN - EXTCRC);
424 ((PushbackInputStream)in).unread(
425 tmpbuf, EXTHDR - EXTCRC, EXTCRC);
426 } else {
427 e.crc = get32(tmpbuf, EXTCRC);
428 e.csize = get32(tmpbuf, EXTSIZ);
429 e.size = get32(tmpbuf, EXTLEN);
430 }
431 }
432 }
433 if (e.size != inf.getBytesWritten()) {
434 throw new ZipException(
435 "invalid entry size (expected " + e.size +
436 " but got " + inf.getBytesWritten() + " bytes)");
437 }
438 if (zipCryption != null) {
439 e.csize -= zipCryption.getEncryptionHeaderSize();
440 }
441 if (e.csize != inf.getBytesRead()) {
442 throw new ZipException(
443 "invalid entry compressed size (expected " + e.csize +
444 " but got " + inf.getBytesRead() + " bytes)");
445 }
446 if (e.crc != crc.getValue()) {
447 throw new ZipException(
448 "invalid entry CRC (expected 0x" + Long.toHexString(e.crc) +
449 " but got 0x" + Long.toHexString(crc.getValue()) + ")");
450 }
451 }
452
453 /*
454 * Reads bytes, blocking until all bytes are read.
455 */
456 private void readFully(byte[] b, int off, int len) throws IOException {
457 while (len > 0) {
458 int n = in.read(b, off, len);
459 if (n == -1) {
460 throw new EOFException();
461 }
462 off += n;
463 len -= n;
464 }
465 }
466
467 }