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