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