1 /*
   2  * Copyright (c) 2013, 2018, 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.nio.Buffer;
  29 import java.nio.ByteBuffer;
  30 import java.nio.file.attribute.FileTime;
  31 import java.security.AccessController;
  32 import java.security.PrivilegedAction;
  33 import java.time.DateTimeException;
  34 import java.time.Instant;
  35 import java.time.LocalDateTime;
  36 import java.time.ZoneId;
  37 import java.util.Date;
  38 import java.util.concurrent.TimeUnit;
  39 
  40 import static java.util.zip.ZipConstants.ENDHDR;
  41 
  42 import jdk.internal.misc.Unsafe;
  43 import sun.nio.ch.DirectBuffer;
  44 
  45 class ZipUtils {
  46 
  47     // used to adjust values between Windows and java epoch
  48     private static final long WINDOWS_EPOCH_IN_MICROSECONDS = -11644473600000000L;
  49 
  50     // used to indicate the corresponding windows time is not available
  51     public static final long WINDOWS_TIME_NOT_AVAILABLE = Long.MIN_VALUE;
  52 
  53     // static final ByteBuffer defaultBuf = ByteBuffer.allocateDirect(0);
  54     static final ByteBuffer defaultBuf = ByteBuffer.allocate(0);
  55 
  56     /**
  57      * Converts Windows time (in microseconds, UTC/GMT) time to FileTime.
  58      */
  59     public static final FileTime winTimeToFileTime(long wtime) {
  60         return FileTime.from(wtime / 10 + WINDOWS_EPOCH_IN_MICROSECONDS,
  61                              TimeUnit.MICROSECONDS);
  62     }
  63 
  64     /**
  65      * Converts FileTime to Windows time.
  66      */
  67     public static final long fileTimeToWinTime(FileTime ftime) {
  68         return (ftime.to(TimeUnit.MICROSECONDS) - WINDOWS_EPOCH_IN_MICROSECONDS) * 10;
  69     }
  70 
  71     /**
  72      * The upper bound of the 32-bit unix time, the "year 2038 problem".
  73      */
  74     public static final long UPPER_UNIXTIME_BOUND = 0x7fffffff;
  75 
  76     /**
  77      * Converts "standard Unix time"(in seconds, UTC/GMT) to FileTime
  78      */
  79     public static final FileTime unixTimeToFileTime(long utime) {
  80         return FileTime.from(utime, TimeUnit.SECONDS);
  81     }
  82 
  83     /**
  84      * Converts FileTime to "standard Unix time".
  85      */
  86     public static final long fileTimeToUnixTime(FileTime ftime) {
  87         return ftime.to(TimeUnit.SECONDS);
  88     }
  89 
  90     /**
  91      /*
  92      * Converts DOS time to Java time (number of milliseconds since epoch).
  93      */
  94     public static long dosToJavaTime(long dtime) {
  95         int year = (int) (((dtime >> 25) & 0x7f) + 1980);
  96         int month = (int) ((dtime >> 21) & 0x0f);
  97         int day = (int) ((dtime >> 16) & 0x1f);
  98         int hour = (int) ((dtime >> 11) & 0x1f);
  99         int minute = (int) ((dtime >> 5) & 0x3f);
 100         int second = (int) ((dtime << 1) & 0x3e);
 101 
 102         if (month > 0 && month < 13 && day > 0 && hour < 24 && minute < 60 && second < 60) {
 103             try {
 104                 LocalDateTime ldt = LocalDateTime.of(year, month, day, hour, minute, second);
 105                 return TimeUnit.MILLISECONDS.convert(ldt.toEpochSecond(
 106                         ZoneId.systemDefault().getRules().getOffset(ldt)), TimeUnit.SECONDS);
 107             } catch (DateTimeException dte) {
 108                 // ignore
 109             }
 110         }
 111         return overflowDosToJavaTime(year, month, day, hour, minute, second);
 112     }
 113 
 114     /*
 115      * Deal with corner cases where an arguably mal-formed DOS time is used
 116      */
 117     @SuppressWarnings("deprecation") // Use of Date constructor
 118     private static long overflowDosToJavaTime(int year, int month, int day,
 119                                               int hour, int minute, int second) {
 120         return new Date(year - 1900, month - 1, day, hour, minute, second).getTime();
 121     }
 122 
 123 
 124     /**
 125      * Converts extended DOS time to Java time, where up to 1999 milliseconds
 126      * might be encoded into the upper half of the returned long.
 127      *
 128      * @param xdostime the extended DOS time value
 129      * @return milliseconds since epoch
 130      */
 131     public static long extendedDosToJavaTime(long xdostime) {
 132         long time = dosToJavaTime(xdostime);
 133         return time + (xdostime >> 32);
 134     }
 135 
 136     /**
 137      * Converts Java time to DOS time.
 138      */
 139     private static long javaToDosTime(long time) {
 140         Instant instant = Instant.ofEpochMilli(time);
 141         LocalDateTime ldt = LocalDateTime.ofInstant(
 142                 instant, ZoneId.systemDefault());
 143         int year = ldt.getYear() - 1980;
 144         if (year < 0) {
 145             return (1 << 21) | (1 << 16);
 146         }
 147         return (year << 25 |
 148             ldt.getMonthValue() << 21 |
 149             ldt.getDayOfMonth() << 16 |
 150             ldt.getHour() << 11 |
 151             ldt.getMinute() << 5 |
 152             ldt.getSecond() >> 1) & 0xffffffffL;
 153     }
 154 
 155     /**
 156      * Converts Java time to DOS time, encoding any milliseconds lost
 157      * in the conversion into the upper half of the returned long.
 158      *
 159      * @param time milliseconds since epoch
 160      * @return DOS time with 2s remainder encoded into upper half
 161      */
 162     public static long javaToExtendedDosTime(long time) {
 163         if (time < 0) {
 164             return ZipEntry.DOSTIME_BEFORE_1980;
 165         }
 166         long dostime = javaToDosTime(time);
 167         return (dostime != ZipEntry.DOSTIME_BEFORE_1980)
 168                 ? dostime + ((time % 2000) << 32)
 169                 : ZipEntry.DOSTIME_BEFORE_1980;
 170     }
 171 
 172     /**
 173      * Fetches unsigned 16-bit value from byte array at specified offset.
 174      * The bytes are assumed to be in Intel (little-endian) byte order.
 175      */
 176     public static final int get16(byte b[], int off) {
 177         return (b[off] & 0xff) | ((b[off + 1] & 0xff) << 8);
 178     }
 179 
 180     /**
 181      * Fetches unsigned 32-bit value from byte array at specified offset.
 182      * The bytes are assumed to be in Intel (little-endian) byte order.
 183      */
 184     public static final long get32(byte b[], int off) {
 185         return (get16(b, off) | ((long)get16(b, off+2) << 16)) & 0xffffffffL;
 186     }
 187 
 188     /**
 189      * Fetches signed 64-bit value from byte array at specified offset.
 190      * The bytes are assumed to be in Intel (little-endian) byte order.
 191      */
 192     public static final long get64(byte b[], int off) {
 193         return get32(b, off) | (get32(b, off+4) << 32);
 194     }
 195 
 196     /**
 197      * Fetches signed 32-bit value from byte array at specified offset.
 198      * The bytes are assumed to be in Intel (little-endian) byte order.
 199      *
 200      */
 201     public static final int get32S(byte b[], int off) {
 202         return (get16(b, off) | (get16(b, off+2) << 16));
 203     }
 204 
 205     // fields access methods
 206     static final int CH(byte[] b, int n) {
 207         return b[n] & 0xff ;
 208     }
 209 
 210     static final int SH(byte[] b, int n) {
 211         return (b[n] & 0xff) | ((b[n + 1] & 0xff) << 8);
 212     }
 213 
 214     static final long LG(byte[] b, int n) {
 215         return ((SH(b, n)) | (SH(b, n + 2) << 16)) & 0xffffffffL;
 216     }
 217 
 218     static final long LL(byte[] b, int n) {
 219         return (LG(b, n)) | (LG(b, n + 4) << 32);
 220     }
 221 
 222     static final long GETSIG(byte[] b) {
 223         return LG(b, 0);
 224     }
 225 
 226     // local file (LOC) header fields
 227     static final long LOCSIG(byte[] b) { return LG(b, 0); } // signature
 228     static final int  LOCVER(byte[] b) { return SH(b, 4); } // version needed to extract
 229     static final int  LOCFLG(byte[] b) { return SH(b, 6); } // general purpose bit flags
 230     static final int  LOCHOW(byte[] b) { return SH(b, 8); } // compression method
 231     static final long LOCTIM(byte[] b) { return LG(b, 10);} // modification time
 232     static final long LOCCRC(byte[] b) { return LG(b, 14);} // crc of uncompressed data
 233     static final long LOCSIZ(byte[] b) { return LG(b, 18);} // compressed data size
 234     static final long LOCLEN(byte[] b) { return LG(b, 22);} // uncompressed data size
 235     static final int  LOCNAM(byte[] b) { return SH(b, 26);} // filename length
 236     static final int  LOCEXT(byte[] b) { return SH(b, 28);} // extra field length
 237 
 238     // extra local (EXT) header fields
 239     static final long EXTCRC(byte[] b) { return LG(b, 4);}  // crc of uncompressed data
 240     static final long EXTSIZ(byte[] b) { return LG(b, 8);}  // compressed size
 241     static final long EXTLEN(byte[] b) { return LG(b, 12);} // uncompressed size
 242 
 243     // end of central directory header (END) fields
 244     static final int  ENDSUB(byte[] b) { return SH(b, 8); }  // number of entries on this disk
 245     static final int  ENDTOT(byte[] b) { return SH(b, 10);}  // total number of entries
 246     static final long ENDSIZ(byte[] b) { return LG(b, 12);}  // central directory size
 247     static final long ENDOFF(byte[] b) { return LG(b, 16);}  // central directory offset
 248     static final int  ENDCOM(byte[] b) { return SH(b, 20);}  // size of zip file comment
 249     static final int  ENDCOM(byte[] b, int off) { return SH(b, off + 20);}
 250 
 251     // zip64 end of central directory recoder fields
 252     static final long ZIP64_ENDTOD(byte[] b) { return LL(b, 24);}  // total number of entries on disk
 253     static final long ZIP64_ENDTOT(byte[] b) { return LL(b, 32);}  // total number of entries
 254     static final long ZIP64_ENDSIZ(byte[] b) { return LL(b, 40);}  // central directory size
 255     static final long ZIP64_ENDOFF(byte[] b) { return LL(b, 48);}  // central directory offset
 256     static final long ZIP64_LOCOFF(byte[] b) { return LL(b, 8);}   // zip64 end offset
 257 
 258     // central directory header (CEN) fields
 259     static final long CENSIG(byte[] b, int pos) { return LG(b, pos + 0); }
 260     static final int  CENVEM(byte[] b, int pos) { return SH(b, pos + 4); }
 261     static final int  CENVER(byte[] b, int pos) { return SH(b, pos + 6); }
 262     static final int  CENFLG(byte[] b, int pos) { return SH(b, pos + 8); }
 263     static final int  CENHOW(byte[] b, int pos) { return SH(b, pos + 10);}
 264     static final long CENTIM(byte[] b, int pos) { return LG(b, pos + 12);}
 265     static final long CENCRC(byte[] b, int pos) { return LG(b, pos + 16);}
 266     static final long CENSIZ(byte[] b, int pos) { return LG(b, pos + 20);}
 267     static final long CENLEN(byte[] b, int pos) { return LG(b, pos + 24);}
 268     static final int  CENNAM(byte[] b, int pos) { return SH(b, pos + 28);}
 269     static final int  CENEXT(byte[] b, int pos) { return SH(b, pos + 30);}
 270     static final int  CENCOM(byte[] b, int pos) { return SH(b, pos + 32);}
 271     static final int  CENDSK(byte[] b, int pos) { return SH(b, pos + 34);}
 272     static final int  CENATT(byte[] b, int pos) { return SH(b, pos + 36);}
 273     static final long CENATX(byte[] b, int pos) { return LG(b, pos + 38);}
 274     static final long CENOFF(byte[] b, int pos) { return LG(b, pos + 42);}
 275 
 276     // The END header is followed by a variable length comment of size < 64k.
 277     static final long END_MAXLEN = 0xFFFF + ENDHDR;
 278     static final int READBLOCKSZ = 128;
 279 
 280     /**
 281      * Loads zip native library, if not already laoded
 282      */
 283     static void loadLibrary() {
 284         SecurityManager sm = System.getSecurityManager();
 285         if (sm == null) {
 286             System.loadLibrary("zip");
 287         } else {
 288             PrivilegedAction<Void> pa = () -> { System.loadLibrary("zip"); return null; };
 289             AccessController.doPrivileged(pa);
 290         }
 291     }
 292 
 293     private static final Unsafe unsafe = Unsafe.getUnsafe();
 294 
 295     private static final long byteBufferArrayOffset = unsafe.objectFieldOffset(ByteBuffer.class, "hb");
 296     private static final long byteBufferOffsetOffset = unsafe.objectFieldOffset(ByteBuffer.class, "offset");
 297 
 298     static byte[] getBufferArray(ByteBuffer byteBuffer) {
 299         return (byte[]) unsafe.getObject(byteBuffer, byteBufferArrayOffset);
 300     }
 301 
 302     static int getBufferOffset(ByteBuffer byteBuffer) {
 303         return unsafe.getInt(byteBuffer, byteBufferOffsetOffset);
 304     }
 305 }