src/bin/unzip/funzip.c

   1 /*
   2   Copyright (c) 1990-2002 Info-ZIP.  All rights reserved.
   3
   4   See the accompanying file LICENSE, version 2000-Apr-09 or later
   5   (the contents of which are also included in unzip.h) for terms of use.
   6   If, for some reason, all these files are missing, the Info-ZIP license
   7   also may be found at:  ftp://ftp.info-zip.org/pub/infozip/license.html
   8 */
   9 /* funzip.c -- by Mark Adler */
  10
  11 #define VERSION "3.94 of 20 January 2002"
  12
  13
  14 /* Copyright history:
  15    - Starting with UnZip 5.41 of 16-April-2000, this source file
  16      is covered by the Info-Zip LICENSE cited above.
  17    - Prior versions of this source file, found in UnZip source packages
  18      up to UnZip 5.40, were put in the public domain.
  19      The original copyright note by Mark Adler was:
  20          "You can do whatever you like with this source file,
  21          though I would prefer that if you modify it and
  22          redistribute it that you include comments to that effect
  23          with your name and the date.  Thank you."
  24
  25    History:
  26    vers     date          who           what
  27    ----   ---------  --------------  ------------------------------------
  28    1.0    13 Aug 92  M. Adler        really simple unzip filter.
  29    1.1    13 Aug 92  M. Adler        cleaned up somewhat, give help if
  30                                      stdin not redirected, warn if more
  31                                      zip file entries after the first.
  32    1.2    15 Aug 92  M. Adler        added check of lengths for stored
  33                                      entries, added more help.
  34    1.3    16 Aug 92  M. Adler        removed redundant #define's, added
  35                                      decryption.
  36    1.4    27 Aug 92  G. Roelofs      added exit(0).
  37    1.5     1 Sep 92  K. U. Rommel    changed read/write modes for OS/2.
  38    1.6     6 Sep 92  G. Roelofs      modified to use dummy crypt.c and
  39                                      crypt.h instead of -DCRYPT.
  40    1.7    23 Sep 92  G. Roelofs      changed to use DOS_OS2; included
  41                                      crypt.c under MS-DOS.
  42    1.8     9 Oct 92  M. Adler        improved inflation error msgs.
  43    1.9    17 Oct 92  G. Roelofs      changed ULONG/UWORD/byte to ulg/ush/uch;
  44                                      renamed inflate_entry() to inflate();
  45                                      adapted to use new, in-place zdecode.
  46    2.0    22 Oct 92  M. Adler        allow filename argument, prompt for
  47                                      passwords and don't echo, still allow
  48                                      command-line password entry, but as an
  49                                      option.
  50    2.1    23 Oct 92  J-l. Gailly     fixed crypt/store bug,
  51                      G. Roelofs      removed crypt.c under MS-DOS, fixed
  52                                      decryption check to compare single byte.
  53    2.2    28 Oct 92  G. Roelofs      removed declaration of key.
  54    2.3    14 Dec 92  M. Adler        replaced fseek (fails on stdin for SCO
  55                                      Unix V.3.2.4).  added quietflg for
  56                                      inflate.c.
  57    3.0    11 May 93  M. Adler        added gzip support
  58    3.1     9 Jul 93  K. U. Rommel    fixed OS/2 pipe bug (PIPE_ERROR)
  59    3.2     4 Sep 93  G. Roelofs      moved crc_32_tab[] to tables.h; used FOPx
  60                                      from unzip.h; nuked OUTB macro and outbuf;
  61                                      replaced flush(); inlined FlushOutput();
  62                                      renamed decrypt to encrypted
  63    3.3    29 Sep 93  G. Roelofs      replaced ReadByte() with NEXTBYTE macro;
  64                                      revised (restored?) flush(); added FUNZIP
  65    3.4    21 Oct 93  G. Roelofs      renamed quietflg to qflag; changed outcnt,
  66                      H. Gessau       second updcrc() arg and flush() arg to ulg;
  67                                      added inflate_free(); added "g =" to null
  68                                      getc(in) to avoid compiler warnings
  69    3.5    31 Oct 93  H. Gessau       changed DOS_OS2 to DOS_NT_OS2
  70    3.6     6 Dec 93  H. Gessau       added "near" to mask_bits[]
  71    3.7     9 Dec 93  G. Roelofs      added extent typecasts to fwrite() checks
  72    3.8    28 Jan 94  GRR/JlG         initialized g variable in main() for gcc
  73    3.81   22 Feb 94  M. Hanning-Lee  corrected usage message
  74    3.82   27 Feb 94  G. Roelofs      added some typecasts to avoid warnings
  75    3.83   22 Jul 94  G. Roelofs      changed fprintf to macro for DLLs
  76     -      2 Aug 94  -               public release with UnZip 5.11
  77     -     28 Aug 94  -               public release with UnZip 5.12
  78    3.84    1 Oct 94  K. U. Rommel    changes for Metaware High C
  79    3.85   29 Oct 94  G. Roelofs      changed fprintf macro to Info
  80    3.86    7 May 95  K. Davis        RISCOS patches;
  81                      P. Kienitz      Amiga patches
  82    3.87   12 Aug 95  G. Roelofs      inflate_free(), DESTROYGLOBALS fixes
  83    3.88    4 Sep 95  C. Spieler      reordered macro to work around MSC 5.1 bug
  84    3.89   22 Nov 95  PK/CS           ifdef'd out updcrc() for ASM_CRC
  85    3.9    17 Dec 95  G. Roelofs      modified for USE_ZLIB (new fillinbuf())
  86     -     30 Apr 96  -               public release with UnZip 5.2
  87    3.91   17 Aug 96  G. Roelofs      main() -> return int (Peter Seebach)
  88    3.92   13 Apr 97  G. Roelofs      minor cosmetic fixes to messages
  89     -     22 Apr 97  -               public release with UnZip 5.3
  90     -     31 May 97  -               public release with UnZip 5.31
  91    3.93   20 Sep 97  G. Roelofs      minor cosmetic fixes to messages
  92     -      3 Nov 97  -               public release with UnZip 5.32
  93     -     28 Nov 98  -               public release with UnZip 5.4
  94     -     16 Apr 00  -               public release with UnZip 5.41
  95     -     14 Jan 01  -               public release with UnZip 5.42
  96    3.94   20 Feb 01  C. Spieler      added support for Deflate64(tm)
  97  */
  98
  99
 100 /*
 101
 102    All funzip does is take a zipfile from stdin and decompress the
 103    first entry to stdout.  The entry has to be either deflated or
 104    stored.  If the entry is encrypted, then the decryption password
 105    must be supplied on the command line as the first argument.
 106
 107    funzip needs to be linked with inflate.o and crypt.o compiled from
 108    the unzip source.  If decryption is desired, the full version of
 109    crypt.c (and crypt.h) from zcrypt28.zip or later must be used.
 110
 111  */
 112
 113 #ifndef FUNZIP
 114 #  define FUNZIP
 115 #endif
 116 #define UNZIP_INTERNAL
 117 #include "unzip.h"
 118 #include "crypt.h"
 119 #include "ttyio.h"
 120
 121 #ifdef EBCDIC
 122 #  undef EBCDIC                 /* don't need ebcdic[] */
 123 #endif
 124 #include "tables.h"             /* crc_32_tab[] */
 125
 126 #ifndef USE_ZLIB  /* zlib's function is called inflate(), too */
 127 #  define UZinflate inflate
 128 #endif
 129
 130 /* PKZIP header definitions */
 131 #define ZIPMAG 0x4b50           /* two-byte zip lead-in */
 132 #define LOCREM 0x0403           /* remaining two bytes in zip signature */
 133 #define LOCSIG 0x04034b50L      /* full signature */
 134 #define LOCFLG 4                /* offset of bit flag */
 135 #define  CRPFLG 1               /*  bit for encrypted entry */
 136 #define  EXTFLG 8               /*  bit for extended local header */
 137 #define LOCHOW 6                /* offset of compression method */
 138 #define LOCTIM 8                /* file mod time (for decryption) */
 139 #define LOCCRC 12               /* offset of crc */
 140 #define LOCSIZ 16               /* offset of compressed size */
 141 #define LOCLEN 20               /* offset of uncompressed length */
 142 #define LOCFIL 24               /* offset of file name field length */
 143 #define LOCEXT 26               /* offset of extra field length */
 144 #define LOCHDR 28               /* size of local header, including LOCREM */
 145 #define EXTHDR 16               /* size of extended local header, inc sig */
 146
 147 /* GZIP header definitions */
 148 #define GZPMAG 0x8b1f           /* two-byte gzip lead-in */
 149 #define GZPHOW 0                /* offset of method number */
 150 #define GZPFLG 1                /* offset of gzip flags */
 151 #define  GZPMUL 2               /* bit for multiple-part gzip file */
 152 #define  GZPISX 4               /* bit for extra field present */
 153 #define  GZPISF 8               /* bit for filename present */
 154 #define  GZPISC 16              /* bit for comment present */
 155 #define  GZPISE 32              /* bit for encryption */
 156 #define GZPTIM 2                /* offset of Unix file modification time */
 157 #define GZPEXF 6                /* offset of extra flags */
 158 #define GZPCOS 7                /* offset of operating system compressed on */
 159 #define GZPHDR 8                /* length of minimal gzip header */
 160
 161 #ifdef THEOS
 162 /* Macros cause stack overflow in compiler */
 163 ush SH(uch* p) { return ((ush)(uch)((p)[0]) | ((ush)(uch)((p)[1]) << 8)); }
 164 ulg LG(uch* p) { return ((ulg)(SH(p)) | ((ulg)(SH((p)+2)) << 16)); }
 165 #else /* !THEOS */
 166 /* Macros for getting two-byte and four-byte header values */
 167 #define SH(p) ((ush)(uch)((p)[0]) | ((ush)(uch)((p)[1]) << 8))
 168 #define LG(p) ((ulg)(SH(p)) | ((ulg)(SH((p)+2)) << 16))
 169 #endif /* ?THEOS */
 170
 171 /* Function prototypes */
 172 static void err OF((int, char *));
 173 #if (defined(USE_DEFLATE64) && defined(__16BIT__))
 174 static int partflush OF((uch *rawbuf, unsigned w));
 175 #endif
 176 int main OF((int, char **));
 177
 178 /* Globals */
 179 FILE *out;                      /* output file (*in moved to G struct) */
 180 ulg outsiz;                     /* total bytes written to out */
 181 int encrypted;                  /* flag to turn on decryption */
 182
 183 /* Masks for inflate.c */
 184 ZCONST ush near mask_bits[] = {
 185     0x0000,
 186     0x0001, 0x0003, 0x0007, 0x000f, 0x001f, 0x003f, 0x007f, 0x00ff,
 187     0x01ff, 0x03ff, 0x07ff, 0x0fff, 0x1fff, 0x3fff, 0x7fff, 0xffff
 188 };
 189
 190
 191 #ifdef USE_ZLIB
 192
 193 int fillinbuf(__G)
 194 __GDEF
 195 /* Fill input buffer for pull-model inflate() in zlib.  Return the number of
 196  * bytes in inbuf. */
 197 {
 198 /*   GRR: check return value from fread(): same as read()?  check errno? */
 199   if ((G.incnt = fread((char *)G.inbuf, 1, INBUFSIZ, G.in)) <= 0)
 200     return 0;
 201   G.inptr = G.inbuf;
 202
 203 #if CRYPT
 204   if (encrypted) {
 205     uch *p;
 206     int n;
 207
 208     for (n = G.incnt, p = G.inptr;  n--;  p++)
 209       zdecode(*p);
 210   }
 211 #endif /* CRYPT */
 212
 213   return G.incnt;
 214
 215 }
 216
 217 #endif /* USE_ZLIB */
 218
 219
 220 #if (!defined(USE_ZLIB) || defined(USE_OWN_CRCTAB))
 221 #ifdef USE_ZLIB
 222 ZCONST uLongf *get_crc_table()
 223 {
 224   return (ZCONST uLongf *)crc_32_tab;
 225 }
 226 #else /* !USE_ZLIB */
 227 ZCONST ulg near *get_crc_table()
 228 {
 229   return crc_32_tab;
 230 }
 231 #endif /* ?USE_ZLIB */
 232 #endif /* !USE_ZLIB || USE_OWN_CRCTAB */
 233
 234
 235 static void err(n, m)
 236 int n;
 237 char *m;
 238 /* Exit on error with a message and a code */
 239 {
 240   Info(slide, 1, ((char *)slide, "funzip error: %s\n", m));
 241   DESTROYGLOBALS();
 242   EXIT(n);
 243 }
 244
 245
 246 #if (defined(USE_DEFLATE64) && defined(__16BIT__))
 247
 248 static int partflush(rawbuf, w)
 249 uch *rawbuf;     /* start of buffer area to flush */
 250 extent w;       /* number of bytes to flush */
 251 {
 252   G.crc32val = crc32(G.crc32val, rawbuf, (extent)w);
 253   if (fwrite((char *)rawbuf,1,(extent)w,out) != (extent)w && !PIPE_ERROR)
 254     err(9, "out of space on stdout");
 255   outsiz += w;
 256   return 0;
 257 }
 258
 259
 260 int flush(w)    /* used by inflate.c (FLUSH macro) */
 261 ulg w;          /* number of bytes to flush */
 262 {
 263     uch *rawbuf;
 264     int ret;
 265
 266     /* On 16-bit systems (MSDOS, OS/2 1.x), the standard C library functions
 267      * cannot handle writes of 64k blocks at once.  For these systems, the
 268      * blocks to flush are split into pieces of 32k or less.
 269      */
 270     rawbuf = slide;
 271     while (w > 0x8000L) {
 272         ret = partflush(rawbuf, 0x8000);
 273         if (ret != PK_OK)
 274             return ret;
 275         w -= 0x8000L;
 276         rawbuf += (unsigned)0x8000;
 277     }
 278     return partflush(rawbuf, (extent)w);
 279 } /* end function flush() */
 280
 281 #else /* !(USE_DEFLATE64 && __16BIT__) */
 282
 283 int flush(w)    /* used by inflate.c (FLUSH macro) */
 284 ulg w;          /* number of bytes to flush */
 285 {
 286   G.crc32val = crc32(G.crc32val, slide, (extent)w);
 287   if (fwrite((char *)slide,1,(extent)w,out) != (extent)w && !PIPE_ERROR)
 288     err(9, "out of space on stdout");
 289   outsiz += w;
 290   return 0;
 291 }
 292
 293 #endif /* ?(USE_DEFLATE64 && __16BIT__) */
 294
 295
 296 int main(argc, argv)
 297 int argc;
 298 char **argv;
 299 /* Given a zipfile on stdin, decompress the first entry to stdout. */
 300 {
 301   ush n;
 302   uch h[LOCHDR];                /* first local header (GZPHDR < LOCHDR) */
 303   int g = 0;                    /* true if gzip format */
 304   unsigned method = 0;          /* initialized here to shut up gcc warning */
 305 #if CRYPT
 306   char *s = " [-password]";
 307   char *p;                      /* password */
 308 #else /* !CRYPT */
 309   char *s = "";
 310 #endif /* ?CRYPT */
 311   CONSTRUCTGLOBALS();
 312
 313   /* skip executable name */
 314   argc--;
 315   argv++;
 316
 317 #if CRYPT
 318   /* get the command line password, if any */
 319   p = (char *)NULL;
 320   if (argc && **argv == '-')
 321   {
 322     argc--;
 323     p = 1 + *argv++;
 324   }
 325 #endif /* CRYPT */
 326
 327 #ifdef MALLOC_WORK
 328   /* The following expression is a cooked-down simplyfication of the
 329      calculation for the work area size of UnZip (see unzip.c).  For
 330      fUnZip, the work area does not need to match the granularity
 331      of the complex unshrink structures, because it only supports
 332      inflation.  But, like in UnZip, the zcalloc() wrapper function
 333      is needed for the allocation, to support the 64kByte buffer on
 334      16-bit systems.
 335    */
 336 # define UZ_SLIDE_CHUNK (sizeof(shrint)+sizeof(uch)+sizeof(uch))
 337 # define UZ_NUMOF_CHUNKS (unsigned)( (WSIZE+UZ_SLIDE_CHUNK-1)/UZ_SLIDE_CHUNK )
 338   G.area.Slide = (uch *)zcalloc(UZ_NUMOF_CHUNKS, UZ_SLIDE_CHUNK);
 339 # undef UZ_SLIDE_CHUNK
 340 # undef UZ_NUMOF_CHUNKS
 341 #endif
 342
 343   /* if no file argument and stdin not redirected, give the user help */
 344   if (argc == 0 && isatty(0))
 345   {
 346     Info(slide, 1, ((char *)slide, "fUnZip (filter UnZip), version %s\n",
 347       VERSION));
 348     Info(slide, 1, ((char *)slide, "usage: ... | funzip%s | ...\n", s));
 349     Info(slide, 1, ((char *)slide, "       ... | funzip%s > outfile\n", s));
 350     Info(slide, 1, ((char *)slide, "       funzip%s infile.zip > outfile\n",s));
 351     Info(slide, 1, ((char *)slide, "       funzip%s infile.gz > outfile\n", s));
 352     Info(slide, 1, ((char *)slide, "Extracts to stdout the gzip file or first\
 353  zip entry of stdin or the given file.\n"));
 354     DESTROYGLOBALS();
 355     EXIT(3);
 356   }
 357
 358   /* prepare to be a binary filter */
 359   if (argc)
 360   {
 361     if ((G.in = fopen(*argv, FOPR)) == (FILE *)NULL)
 362       err(2, "cannot find input file");
 363   }
 364   else
 365   {
 366 #ifdef DOS_FLX_NLM_OS2_W32
 367 #if (defined(__HIGHC__) && !defined(FLEXOS))
 368     setmode(stdin, _BINARY);
 369 #else
 370     setmode(0, O_BINARY);  /* some buggy C libraries require BOTH setmode() */
 371 #endif                     /*  call AND the fdopen() in binary mode :-( */
 372 #endif /* DOS_FLX_NLM_OS2_W32 */
 373
 374 #ifdef RISCOS
 375     G.in = stdin;
 376 #else
 377     if ((G.in = fdopen(0, FOPR)) == (FILE *)NULL)
 378       err(2, "cannot find stdin");
 379 #endif
 380   }
 381
 382 #ifdef DOS_FLX_H68_NLM_OS2_W32
 383 #if (defined(__HIGHC__) && !defined(FLEXOS))
 384   setmode(stdout, _BINARY);
 385 #else
 386   setmode(1, O_BINARY);
 387 #endif
 388 #endif /* DOS_FLX_H68_NLM_OS2_W32 */
 389
 390 #ifdef RISCOS
 391   out = stdout;
 392 #else
 393   if ((out = fdopen(1, FOPW)) == (FILE *)NULL)
 394     err(2, "cannot write to stdout");
 395 #endif
 396
 397   /* read local header, check validity, and skip name and extra fields */
 398   n = getc(G.in);  n |= getc(G.in) << 8;
 399   if (n == ZIPMAG)
 400   {
 401     if (fread((char *)h, 1, LOCHDR, G.in) != LOCHDR || SH(h) != LOCREM)
 402       err(3, "invalid zipfile");
 403     switch (method = SH(h + LOCHOW)) {
 404       case STORED:
 405       case DEFLATED:
 406 #ifdef USE_DEFLATE64
 407       case ENHDEFLATED:
 408 #endif
 409         break;
 410       default:
 411         err(3, "first entry not deflated or stored--cannot unpack");
 412         break;
 413     }
 414     for (n = SH(h + LOCFIL); n--; ) g = getc(G.in);
 415     for (n = SH(h + LOCEXT); n--; ) g = getc(G.in);
 416     g = 0;
 417     encrypted = h[LOCFLG] & CRPFLG;
 418   }
 419   else if (n == GZPMAG)
 420   {
 421     if (fread((char *)h, 1, GZPHDR, G.in) != GZPHDR)
 422       err(3, "invalid gzip file");
 423     if ((method = h[GZPHOW]) != DEFLATED && method != ENHDEFLATED)
 424       err(3, "gzip file not deflated");
 425     if (h[GZPFLG] & GZPMUL)
 426       err(3, "cannot handle multi-part gzip files");
 427     if (h[GZPFLG] & GZPISX)
 428     {
 429       n = getc(G.in);  n |= getc(G.in) << 8;
 430       while (n--) g = getc(G.in);
 431     }
 432     if (h[GZPFLG] & GZPISF)
 433       while ((g = getc(G.in)) != 0 && g != EOF) ;
 434     if (h[GZPFLG] & GZPISC)
 435       while ((g = getc(G.in)) != 0 && g != EOF) ;
 436     g = 1;
 437     encrypted = h[GZPFLG] & GZPISE;
 438   }
 439   else
 440     err(3, "input not a zip or gzip file");
 441
 442   /* if entry encrypted, decrypt and validate encryption header */
 443   if (encrypted)
 444 #if CRYPT
 445     {
 446       ush i, e;
 447
 448       if (p == (char *)NULL) {
 449         if ((p = (char *)malloc(IZ_PWLEN+1)) == (char *)NULL)
 450           err(1, "out of memory");
 451         else if ((p = getp("Enter password: ", p, IZ_PWLEN+1)) == (char *)NULL)
 452           err(1, "no tty to prompt for password");
 453       }
 454 #if (defined(USE_ZLIB) && !defined(USE_OWN_CRCTAB))
 455       /* initialize crc_32_tab pointer for decryption */
 456       CRC_32_TAB = (ZCONST ulg Far *)get_crc_table();
 457 #endif
 458       init_keys(p);
 459       for (i = 0; i < RAND_HEAD_LEN; i++)
 460         e = NEXTBYTE;
 461       if (e != (ush)(h[LOCFLG] & EXTFLG ? h[LOCTIM + 1] : h[LOCCRC + 3]))
 462         err(3, "incorrect password for first entry");
 463     }
 464 #else /* !CRYPT */
 465     err(3, "cannot decrypt entry (need to recompile with full crypt.c)");
 466 #endif /* ?CRYPT */
 467
 468   /* prepare output buffer and crc */
 469   G.outptr = slide;
 470   G.outcnt = 0L;
 471   outsiz = 0L;
 472   G.crc32val = CRCVAL_INITIAL;
 473
 474   /* decompress */
 475   if (g || h[LOCHOW])
 476   {                             /* deflated entry */
 477     int r;
 478
 479 #ifdef USE_ZLIB
 480     /* need to allocate and prepare input buffer */
 481     if ((G.inbuf = (uch *)malloc(INBUFSIZ)) == (uch *)NULL)
 482        err(1, "out of memory");
 483 #endif /* USE_ZLIB */
 484     if ((r = UZinflate(__G__ (method == ENHDEFLATED))) != 0) {
 485       if (r == 3)
 486         err(1, "out of memory");
 487       else
 488         err(4, "invalid compressed data--format violated");
 489     }
 490     inflate_free(__G);
 491   }
 492   else
 493   {                             /* stored entry */
 494     register ulg n;
 495
 496     n = LG(h + LOCLEN);
 497 #if CRYPT
 498     if (n != LG(h + LOCSIZ) - (encrypted ? RAND_HEAD_LEN : 0)) {
 499 #else
 500     if (n != LG(h + LOCSIZ)) {
 501 #endif
 502       Info(slide, 1, ((char *)slide, "len %ld, siz %ld\n", n, LG(h + LOCSIZ)));
 503       err(4, "invalid compressed data--length mismatch");
 504     }
 505     while (n--) {
 506       ush c = getc(G.in);
 507 #if CRYPT
 508       if (encrypted)
 509         zdecode(c);
 510 #endif
 511       *G.outptr++ = (uch)c;
 512 #if (defined(USE_DEFLATE64) && defined(__16BIT__))
 513       if (++G.outcnt == (WSIZE>>1))     /* do FlushOutput() */
 514 #else
 515       if (++G.outcnt == WSIZE)    /* do FlushOutput() */
 516 #endif
 517       {
 518         G.crc32val = crc32(G.crc32val, slide, (extent)G.outcnt);
 519         if (fwrite((char *)slide, 1,(extent)G.outcnt,out) != (extent)G.outcnt
 520             && !PIPE_ERROR)
 521           err(9, "out of space on stdout");
 522         outsiz += G.outcnt;
 523         G.outptr = slide;
 524         G.outcnt = 0L;
 525       }
 526     }
 527   }
 528   if (G.outcnt)   /* flush one last time; no need to reset G.outptr/outcnt */
 529   {
 530     G.crc32val = crc32(G.crc32val, slide, (extent)G.outcnt);
 531     if (fwrite((char *)slide, 1,(extent)G.outcnt,out) != (extent)G.outcnt
 532         && !PIPE_ERROR)
 533       err(9, "out of space on stdout");
 534     outsiz += G.outcnt;
 535   }
 536   fflush(out);
 537
 538   /* if extended header, get it */
 539   if (g)
 540   {
 541     if (fread((char *)h + LOCCRC, 1, 8, G.in) != 8)
 542       err(3, "gzip file ended prematurely");
 543   }
 544   else
 545     if ((h[LOCFLG] & EXTFLG) &&
 546         fread((char *)h + LOCCRC - 4, 1, EXTHDR, G.in) != EXTHDR)
 547       err(3, "zipfile ended prematurely");
 548
 549   /* validate decompression */
 550   if (LG(h + LOCCRC) != G.crc32val)
 551     err(4, "invalid compressed data--crc error");
 552   if (LG((g ? (h + LOCSIZ) : (h + LOCLEN))) != outsiz)
 553     err(4, "invalid compressed data--length error");
 554
 555   /* check if there are more entries */
 556   if (!g && fread((char *)h, 1, 4, G.in) == 4 && LG(h) == LOCSIG)
 557     Info(slide, 1, ((char *)slide,
 558       "funzip warning: zipfile has more than one entry--rest ignored\n"));
 559
 560   DESTROYGLOBALS();
 561   RETURN (0);
 562 }