From: Paul Eggert Date: Sat, 3 Jul 2010 03:41:11 +0000 (-0700) Subject: Decode FHCRC flag properly, as per Internet RFC 1952. X-Git-Tag: v1.5~70 X-Git-Url: https://git.gag.com/?a=commitdiff_plain;h=97e225c0e8ee24f3fc9ff7c5cec63e74aefbb6a0;p=debian%2Fgzip Decode FHCRC flag properly, as per Internet RFC 1952. Problem reported by Greg Roelofs in: http://lists.gnu.org/archive/html/bug-gzip/2010-06/msg00003.html * gzip.c (discard_input_bytes): New function. (get_method): Check header checksum, if given. We never generate it, but other programs may. * gzip.h (HEADER_CRC): Renamed from CONTINUATION. All uses changed. * tailor.h [defined __50SERIES]: Remove PRIMOS stuff that was obsolete anyway and would have made this patch harder to maintain. (get_char, put_char): Remove. * zip.c (zip): Use put_byte instead of the now-removed put_char. --- diff --git a/gzip.c b/gzip.c index 411ca42..0443e16 100644 --- a/gzip.c +++ b/gzip.c @@ -302,6 +302,7 @@ local void treat_file OF((char *iname)); local int create_outfile OF((void)); local char *get_suffix OF((char *name)); local int open_input_file OF((char *iname, struct stat *sbuf)); +local void discard_input_bytes OF((size_t nbytes, unsigned int flags)); local int make_ofname OF((void)); local void shorten_name OF((char *name)); local int get_method OF((int in)); @@ -1246,6 +1247,25 @@ local int make_ofname() return WARNING; } +/* Discard NBYTES input bytes from the input, or up through the next + zero byte if NBYTES == (size_t) -1. If FLAGS say that the header + CRC should be computed, update the CRC accordingly. */ +static void +discard_input_bytes (nbytes, flags) + size_t nbytes; + unsigned int flags; +{ + while (nbytes != 0) + { + uch c = get_byte (); + if (flags & HEADER_CRC) + updcrc (&c, 1); + if (nbytes != (size_t) -1) + nbytes--; + else if (! c) + break; + } +} /* ======================================================================== * Check the magic number of the input file and update ofname if an @@ -1262,7 +1282,7 @@ local int get_method(in) int in; /* input file descriptor */ { uch flags; /* compression flags */ - char magic[2]; /* magic header */ + uch magic[10]; /* magic header */ int imagic0; /* first magic byte or EOF */ int imagic1; /* like magic[1], but can represent EOF */ ulg stamp; /* time stamp */ @@ -1272,19 +1292,19 @@ local int get_method(in) */ if (force && to_stdout) { imagic0 = try_byte(); - magic[0] = (char) imagic0; + magic[0] = imagic0; imagic1 = try_byte (); - magic[1] = (char) imagic1; + magic[1] = imagic1; /* If try_byte returned EOF, magic[1] == (char) EOF. */ } else { - magic[0] = (char)get_byte(); + magic[0] = get_byte (); imagic0 = 0; if (magic[0]) { - magic[1] = (char)get_byte(); + magic[1] = get_byte (); imagic1 = 0; /* avoid lint warning */ } else { imagic1 = try_byte (); - magic[1] = (char) imagic1; + magic[1] = imagic1; } } method = -1; /* unknown yet */ @@ -1314,13 +1334,6 @@ local int get_method(in) exit_code = ERROR; return -1; } - if ((flags & CONTINUATION) != 0) { - fprintf(stderr, - "%s: %s is a multi-part gzip file -- not supported\n", - program_name, ifname); - exit_code = ERROR; - if (force <= 1) return -1; - } if ((flags & RESERVED) != 0) { fprintf(stderr, "%s: %s has flags 0x%x -- not supported\n", @@ -1338,44 +1351,52 @@ local int get_method(in) time_stamp.tv_nsec = 0; } - (void)get_byte(); /* Ignore extra flags for the moment */ - (void)get_byte(); /* Ignore OS type for the moment */ + magic[8] = get_byte (); /* Ignore extra flags. */ + magic[9] = get_byte (); /* Ignore OS type. */ + + if (flags & HEADER_CRC) + { + magic[2] = DEFLATED; + magic[3] = flags; + magic[4] = stamp & 0xff; + magic[5] = (stamp >> 8) & 0xff; + magic[6] = (stamp >> 16) & 0xff; + magic[7] = stamp >> 24; + updcrc (NULL, 0); + updcrc (magic, 10); + } - if ((flags & CONTINUATION) != 0) { - unsigned part = (unsigned)get_byte(); - part |= ((unsigned)get_byte())<<8; - if (verbose) { - fprintf(stderr,"%s: %s: part number %u\n", - program_name, ifname, part); - } - } if ((flags & EXTRA_FIELD) != 0) { - unsigned len = (unsigned)get_byte(); - len |= ((unsigned)get_byte())<<8; + uch lenbuf[2]; + size_t len = lenbuf[0] = get_byte (); + len |= (lenbuf[1] = get_byte ()) << 8; if (verbose) { fprintf(stderr,"%s: %s: extra field of %u bytes ignored\n", program_name, ifname, len); } - while (len--) (void)get_byte(); + if (flags & HEADER_CRC) + updcrc (lenbuf, 2); + discard_input_bytes (len, flags); } /* Get original file name if it was truncated */ if ((flags & ORIG_NAME) != 0) { if (no_name || (to_stdout && !list) || part_nb > 1) { /* Discard the old name */ - char c; /* dummy used for NeXTstep 3.0 cc optimizer bug */ - do {c=get_byte();} while (c != 0); + discard_input_bytes (-1, flags); } else { /* Copy the base name. Keep a directory prefix intact. */ char *p = gzip_base_name (ofname); char *base = p; for (;;) { - *p = (char)get_char(); + *p = (char) get_byte (); if (*p++ == '\0') break; if (p >= ofname+sizeof(ofname)) { gzip_error ("corrupted input -- file name too large"); } } + if (flags & HEADER_CRC) + updcrc ((uch *) base, p - base); p = gzip_base_name (base); memmove (base, p, strlen (p) + 1); /* If necessary, adapt the name to local OS conventions: */ @@ -1388,8 +1409,25 @@ local int get_method(in) /* Discard file comment if any */ if ((flags & COMMENT) != 0) { - while (get_char() != 0) /* null */ ; + discard_input_bytes (-1, flags); } + + if (flags & HEADER_CRC) + { + unsigned int crc16 = updcrc (magic, 0) & 0xffff; + unsigned int header16 = get_byte (); + header16 |= ((unsigned int) get_byte ()) << 8; + if (header16 != crc16) + { + fprintf (stderr, + "%s: %s: header checksum %x != computed checksum %x\n", + program_name, ifname, header16, crc16); + exit_code = ERROR; + if (force <= 1) + return -1; + } + } + if (part_nb == 1) { header_bytes = inptr + 2*4; /* include crc and size */ } diff --git a/gzip.h b/gzip.h index ddc4401..cacbc5b 100644 --- a/gzip.h +++ b/gzip.h @@ -172,7 +172,7 @@ typedef int file_t; /* Do not use stdio */ /* gzip flag byte */ #define ASCII_FLAG 0x01 /* bit 0 set: file probably ascii text */ -#define CONTINUATION 0x02 /* bit 1 set: continuation of multi-part gzip file */ +#define HEADER_CRC 0x02 /* bit 1 set: CRC16 for the gzip header */ #define EXTRA_FIELD 0x04 /* bit 2 set: extra field present */ #define ORIG_NAME 0x08 /* bit 3 set: original file name present */ #define COMMENT 0x10 /* bit 4 set: file comment present */ diff --git a/tailor.h b/tailor.h index de02ae0..4fe0da0 100644 --- a/tailor.h +++ b/tailor.h @@ -227,21 +227,6 @@ # endif #endif -#ifdef __50SERIES /* Prime/PRIMOS */ -# define PATH_SEP '>' -# define STDC_HEADERS -# define NO_STDIN_FSTAT -# define NO_SIZE_CHECK -# define RECORD_IO 1 -# define casemap(c) tolow(c) /* Force file names to lower case */ -# define put_char(c) put_byte((c) & 0x7F) -# define get_char(c) ascii2pascii(get_byte()) -# define OS_CODE 0x0F /* temporary, subject to change */ -# ifdef SIGTERM -# undef SIGTERM /* We don't want a signal handler for SIGTERM */ -# endif -#endif - #if defined(pyr) && !defined(NOMEMCPY) /* Pyramid */ # define NOMEMCPY /* problem with overlapping copies */ #endif @@ -307,11 +292,3 @@ #ifndef OPEN # define OPEN(name, flags, mode) open_safer (name, flags, mode) #endif - -#ifndef get_char -# define get_char() get_byte() -#endif - -#ifndef put_char -# define put_char(c) put_byte(c) -#endif diff --git a/zip.c b/zip.c index dc4a21c..b0452ac 100644 --- a/zip.c +++ b/zip.c @@ -76,7 +76,7 @@ int zip(in, out) if (save_orig_name) { char *p = gzip_base_name (ifname); /* Don't save the directory part. */ do { - put_char(*p); + put_byte (*p); } while (*p++); } header_bytes = (off_t)outcnt;