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gpgtar: List and extract using extended headers.

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* tools/gpgtar.h (TF_EXTHDR, TF_GEXTHDR): New.
* tools/gpgtar-list.c (parse_header): Set the new type flags.
(parse_extended_header): New.
(read_header): Add arg r_extheader and parse extended header.
(print_header): Consult the extended header.
(gpgtar_list): Pass an extended header object.
(gpgtar_read_header): Ditto.
(gpgtar_print_header): Ditto.
* tools/gpgtar-extract.c (extract): New arg exthdr and factor name
checking out to ...
(check_suspicious_name): new.
(extract_regular): Add arg exthdr and consult it.
(extract_directory): Likewise.
(gpgtar_extract): Provide extheader object.
--

GnuPG-bug-id: 5754
This commit is contained in:
Werner Koch 2022-01-09 18:34:04 +01:00
parent 3a1c556b2c
commit 99a8b1f138
No known key found for this signature in database
GPG Key ID: E3FDFF218E45B72B
4 changed files with 272 additions and 62 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

7
tools/gpgtar-create.c
View File

@ -17,6 +17,7 @@
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, see <https://www.gnu.org/licenses/>.
* SPDX-License-Identifier: GPL-3.0-or-later
*/
#include <config.h>
@ -293,8 +294,10 @@ add_entry (const char *dname, const char *entryname, scanctrl_t scanctrl)
xfree (hdr);
else
{
/* FIXME: We don't have the extended info yet available so we
* can't print them. */
if (opt.verbose)
gpgtar_print_header (hdr, log_get_stream ());
gpgtar_print_header (hdr, NULL, log_get_stream ());
*scanctrl->flist_tail = hdr;
scanctrl->flist_tail = &hdr->next;
}
@ -771,7 +774,7 @@ build_header (void *record, tar_header_t hdr, strlist_t *r_exthdr)
hdr->name, gpg_strerror (err));
return err;
}
sl->flags = 2; /* Mark as linkname */
sl->flags = 2; /* Mark as linkpath */
}
}
#endif /*!HAVE_W32_SYSTEM*/

122
tools/gpgtar-extract.c
View File

@ -1,4 +1,6 @@
/* gpgtar-extract.c - Extract from a TAR archive
* Copyright (C) 2016-2017, 2019-2022 g10 Code GmbH
* Copyright (C) 2010, 2012, 2013 Werner Koch
* Copyright (C) 2010 Free Software Foundation, Inc.
*
* This file is part of GnuPG.
@ -15,6 +17,7 @@
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, see <https://www.gnu.org/licenses/>.
* SPDX-License-Identifier: GPL-3.0-or-later
*/
#include <config.h>
@ -33,26 +36,66 @@
#include "../common/ccparray.h"
#include "gpgtar.h"
static gpg_error_t
check_suspicious_name (const char *name)
{
size_t n;
n = strlen (name);
#ifdef HAVE_DOSISH_SYSTEM
if (strchr (name, '\\'))
{
log_error ("filename '%s' contains a backslash - "
"can't extract on this system\n", name);
return gpg_error (GPG_ERR_INV_NAME);
}
#endif /*HAVE_DOSISH_SYSTEM*/
if (!n
|| strstr (name, "//")
|| strstr (name, "/../")
|| !strncmp (name, "../", 3)
|| (n >= 3 && !strcmp (name+n-3, "/.." )))
{
log_error ("filename '%s' has suspicious parts - not extracting\n",
name);
return gpg_error (GPG_ERR_INV_NAME);
}
return 0;
}
static gpg_error_t
extract_regular (estream_t stream, const char *dirname,
tarinfo_t info, tar_header_t hdr)
tarinfo_t info, tar_header_t hdr, strlist_t exthdr)
{
gpg_error_t err;
char record[RECORDSIZE];
size_t n, nbytes, nwritten;
char *fname;
char *fname_buffer = NULL;
const char *fname;
estream_t outfp = NULL;
strlist_t sl;
fname = strconcat (dirname, "/", hdr->name, NULL);
if (!fname)
fname = hdr->name;
for (sl = exthdr; sl; sl = sl->next)
if (sl->flags == 1)
fname = sl->d;
err = check_suspicious_name (fname);
if (err)
goto leave;
fname_buffer = strconcat (dirname, "/", fname, NULL);
if (!fname_buffer)
{
err = gpg_error_from_syserror ();
log_error ("error creating filename: %s\n", gpg_strerror (err));
goto leave;
}
else
err = 0;
fname = fname_buffer;
if (opt.dry_run)
outfp = es_fopenmem (0, "wb");
@ -97,29 +140,36 @@ extract_regular (estream_t stream, const char *dirname,
log_error ("error removing incomplete file '%s': %s\n",
fname, gpg_strerror (gpg_error_from_syserror ()));
}
xfree (fname);
xfree (fname_buffer);
return err;
}
static gpg_error_t
extract_directory (const char *dirname, tar_header_t hdr)
extract_directory (const char *dirname, tar_header_t hdr, strlist_t exthdr)
{
gpg_error_t err;
char *fname;
size_t prefixlen;
const char *name;
char *fname = NULL;
strlist_t sl;
prefixlen = strlen (dirname) + 1;
fname = strconcat (dirname, "/", hdr->name, NULL);
name = hdr->name;
for (sl = exthdr; sl; sl = sl->next)
if (sl->flags == 1)
name = sl->d;
err = check_suspicious_name (name);
if (err)
goto leave;
fname = strconcat (dirname, "/", name, NULL);
if (!fname)
{
err = gpg_error_from_syserror ();
log_error ("error creating filename: %s\n", gpg_strerror (err));
goto leave;
}
else
err = 0;
/* Remove a possible trailing slash. */
if (fname[strlen (fname)-1] == '/')
fname[strlen (fname)-1] = 0;
@ -136,8 +186,13 @@ extract_directory (const char *dirname, tar_header_t hdr)
{
/* Try to create the directory with parents but keep the
original error code in case of a failure. */
char *p;
int rc = 0;
char *p;
size_t prefixlen;
/* (PREFIXLEN is the length of the new directory we use to
* extract the tarball.) */
prefixlen = strlen (dirname) + 1;
for (p = fname+prefixlen; (p = strchr (p, '/')); p++)
{
@ -165,36 +220,15 @@ extract_directory (const char *dirname, tar_header_t hdr)
static gpg_error_t
extract (estream_t stream, const char *dirname, tarinfo_t info,
tar_header_t hdr)
tar_header_t hdr, strlist_t exthdr)
{
gpg_error_t err;
size_t n;
n = strlen (hdr->name);
#ifdef HAVE_DOSISH_SYSTEM
if (strchr (hdr->name, '\\'))
{
log_error ("filename '%s' contains a backslash - "
"can't extract on this system\n", hdr->name);
return gpg_error (GPG_ERR_INV_NAME);
}
#endif /*HAVE_DOSISH_SYSTEM*/
if (!n
|| strstr (hdr->name, "//")
|| strstr (hdr->name, "/../")
|| !strncmp (hdr->name, "../", 3)
|| (n >= 3 && !strcmp (hdr->name+n-3, "/.." )))
{
log_error ("filename '%s' has suspicious parts - not extracting\n",
hdr->name);
return gpg_error (GPG_ERR_INV_NAME);
}
if (hdr->typeflag == TF_REGULAR || hdr->typeflag == TF_UNKNOWN)
err = extract_regular (stream, dirname, info, hdr);
err = extract_regular (stream, dirname, info, hdr, exthdr);
else if (hdr->typeflag == TF_DIRECTORY)
err = extract_directory (dirname, hdr);
err = extract_directory (dirname, hdr, exthdr);
else
{
char record[RECORDSIZE];
@ -286,6 +320,7 @@ gpgtar_extract (const char *filename, int decrypt)
estream_t stream;
estream_t cipher_stream = NULL;
tar_header_t header = NULL;
strlist_t extheader = NULL;
const char *dirprefix = NULL;
char *dirname = NULL;
struct tarinfo_s tarinfo_buffer;
@ -388,19 +423,22 @@ gpgtar_extract (const char *filename, int decrypt)
for (;;)
{
err = gpgtar_read_header (stream, tarinfo, &header);
err = gpgtar_read_header (stream, tarinfo, &header, &extheader);
if (err || header == NULL)
goto leave;
err = extract (stream, dirname, tarinfo, header);
err = extract (stream, dirname, tarinfo, header, extheader);
if (err)
goto leave;
free_strlist (extheader);
extheader = NULL;
xfree (header);
header = NULL;
}
leave:
free_strlist (extheader);
xfree (header);
xfree (dirname);
if (stream != es_stdin)

198
tools/gpgtar-list.c
View File

@ -1,4 +1,6 @@
/* gpgtar-list.c - List a TAR archive
* Copyright (C) 2016-2017, 2019-2022 g10 Code GmbH
* Copyright (C) 2010, 2012, 2013 Werner Koch
* Copyright (C) 2010 Free Software Foundation, Inc.
*
* This file is part of GnuPG.
@ -15,6 +17,7 @@
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, see <https://www.gnu.org/licenses/>.
* SPDX-License-Identifier: GPL-3.0-or-later
*/
#include <config.h>
@ -22,7 +25,6 @@
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <assert.h>
#include "../common/i18n.h"
#include "gpgtar.h"
@ -160,11 +162,15 @@ parse_header (const void *record, const char *filename, tarinfo_t info)
case '5': header->typeflag = TF_DIRECTORY; break;
case '6': header->typeflag = TF_FIFO; break;
case '7': header->typeflag = TF_RESERVED; break;
case 'g': header->typeflag = TF_GEXTHDR; break;
case 'x': header->typeflag = TF_EXTHDR; break;
default: header->typeflag = TF_UNKNOWN; break;
}
/* Compute the number of data records following this header. */
if (header->typeflag == TF_REGULAR || header->typeflag == TF_UNKNOWN)
if (header->typeflag == TF_REGULAR
|| header->typeflag == TF_EXTHDR
|| header->typeflag == TF_UNKNOWN)
header->nrecords = (header->size + RECORDSIZE-1)/RECORDSIZE;
else
header->nrecords = 0;
@ -181,18 +187,93 @@ parse_header (const void *record, const char *filename, tarinfo_t info)
return header;
}
/* Parse the extended header. This funcion may modify BUFFER. */
static gpg_error_t
parse_extended_header (const char *fname,
char *buffer, size_t buflen, strlist_t *r_exthdr)
{
unsigned int reclen;
unsigned char *p, *record;
strlist_t sl;
while (buflen)
{
record = buffer; /* Remember begin of record. */
reclen = 0;
for (p = buffer; buflen && digitp (p); buflen--, p++)
{
reclen *= 10;
reclen += (*p - '0');
}
if (!buflen || *p != ' ')
{
log_error ("%s: malformed record length in extended header\n", fname);
return gpg_error (GPG_ERR_INV_RECORD);
}
p++; /* Skip space. */
buflen--;
if (buflen + (p-record) < reclen)
{
log_error ("%s: extended header record larger"
" than total extended header data\n", fname);
return gpg_error (GPG_ERR_INV_RECORD);
}
if (reclen < (p-record)+2 || record[reclen-1] != '\n')
{
log_error ("%s: malformed extended header record\n", fname);
return gpg_error (GPG_ERR_INV_RECORD);
}
record[reclen-1] = 0; /* For convenience change LF to a Nul. */
reclen -= (p-record);
/* P points to the begin of the keyword and RECLEN is the
* remaining length of the record excluding the LF. */
if (memchr (p, 0, reclen-1)
&& (!strncmp (p, "path=", 5) || !strncmp (p, "linkpath=", 9)))
{
log_error ("%s: extended header record has an embedded nul"
" - ignoring\n", fname);
}
else if (!strncmp (p, "path=", 5))
{
sl = add_to_strlist_try (r_exthdr, p+5);
if (!sl)
return gpg_error_from_syserror ();
sl->flags = 1; /* Mark as path */
}
else if (!strncmp (p, "linkpath=", 9))
{
sl = add_to_strlist_try (r_exthdr, p+9);
if (!sl)
return gpg_error_from_syserror ();
sl->flags = 2; /* Mark as linkpath */
}
buffer = p + reclen;
buflen -= reclen;
}
return 0;
}
/* Read the next block, assuming it is a tar header. Returns a header
object on success in R_HEADER, or an error. If the stream is
consumed, R_HEADER is set to NULL. In case of an error an error
message has been printed. */
* object on success in R_HEADER, or an error. If the stream is
* consumed (i.e. end-of-archive), R_HEADER is set to NULL. In case
* of an error an error message is printed. If the header is an
* extended header, a string list is allocated and stored at
* R_EXTHEADER; the caller should provide a pointer to NULL. Such an
* extended header is fully processed here and the returned R_HEADER
* has then the next regular header. */
static gpg_error_t
read_header (estream_t stream, tarinfo_t info, tar_header_t *r_header)
read_header (estream_t stream, tarinfo_t info,
tar_header_t *r_header, strlist_t *r_extheader)
{
gpg_error_t err;
char record[RECORDSIZE];
int i;
tar_header_t hdr;
char *buffer;
size_t buflen, nrec;
err = read_record (stream, record);
if (err)
@ -224,7 +305,67 @@ read_header (estream_t stream, tarinfo_t info, tar_header_t *r_header)
}
*r_header = parse_header (record, es_fname_get (stream), info);
return *r_header ? 0 : gpg_error_from_syserror ();
if (!*r_header)
return gpg_error_from_syserror ();
hdr = *r_header;
if (hdr->typeflag != TF_EXTHDR || !r_extheader)
return 0;
/* Read the extended header. */
if (!hdr->nrecords)
{
/* More than 64k for an extedned header is surely too large. */
log_info ("%s: warning: empty extended header\n",
es_fname_get (stream));
return 0;
}
if (hdr->nrecords > 65536 / RECORDSIZE)
{
/* More than 64k for an extedned header is surely too large. */
log_error ("%s: extended header too large - skipping\n",
es_fname_get (stream));
return 0;
}
buffer = xtrymalloc (hdr->nrecords * RECORDSIZE);
if (!buffer)
{
err = gpg_error_from_syserror ();
log_error ("%s: error allocating space for extended header: %s\n",
es_fname_get (stream), gpg_strerror (err));
return err;
}
buflen = 0;
for (nrec=0; nrec < hdr->nrecords;)
{
err = read_record (stream, buffer + buflen);
if (err)
{
xfree (buffer);
return err;
}
info->nblocks++;
nrec++;
if (nrec < hdr->nrecords || (hdr->size && !(hdr->size % RECORDSIZE)))
buflen += RECORDSIZE;
else
buflen += (hdr->size % RECORDSIZE);
}
err = parse_extended_header (es_fname_get (stream),
buffer, buflen, r_extheader);
if (err)
{
free_strlist (*r_extheader);
*r_extheader = NULL;
}
xfree (buffer);
/* Now tha the extedned header has been read, we read the next
* header without allowing an extended header. */
return read_header (stream, info, r_header, NULL);
}
@ -249,11 +390,13 @@ skip_data (estream_t stream, tarinfo_t info, tar_header_t header)
static void
print_header (tar_header_t header, estream_t out)
print_header (tar_header_t header, strlist_t extheader, estream_t out)
{
unsigned long mask;
char modestr[10+1];
int i;
strlist_t sl;
const char *name, *linkname;
*modestr = '?';
switch (header->typeflag)
@ -266,6 +409,8 @@ print_header (tar_header_t header, estream_t out)
case TF_DIRECTORY:*modestr = 'd'; break;
case TF_FIFO: *modestr = 'f'; break;
case TF_RESERVED: *modestr = '='; break;
case TF_EXTHDR: break;
case TF_GEXTHDR: break;
case TF_UNKNOWN: break;
case TF_NOTSUP: break;
}
@ -279,9 +424,25 @@ print_header (tar_header_t header, estream_t out)
modestr[9] = modestr[9] == 'x'? 't':'T';
modestr[10] = 0;
es_fprintf (out, "%s %lu %lu/%lu %12llu %s %s\n",
/* FIXME: We do not parse the linkname unless its part of an
* extended header. */
name = header->name;
linkname = header->typeflag == TF_SYMLINK? "?" : NULL;
for (sl = extheader; sl; sl = sl->next)
{
if (sl->flags == 1)
name = sl->d;
else if (sl->flags == 2)
linkname = sl->d;
}
es_fprintf (out, "%s %lu %lu/%lu %12llu %s %s%s%s\n",
modestr, header->nlink, header->uid, header->gid, header->size,
isotimestamp (header->mtime), header->name);
isotimestamp (header->mtime),
name,
linkname? " -> " : "",
linkname? linkname : "");
}
@ -295,6 +456,7 @@ gpgtar_list (const char *filename, int decrypt)
estream_t stream;
estream_t cipher_stream = NULL;
tar_header_t header = NULL;
strlist_t extheader = NULL;
struct tarinfo_s tarinfo_buffer;
tarinfo_t tarinfo = &tarinfo_buffer;
@ -360,20 +522,23 @@ gpgtar_list (const char *filename, int decrypt)
for (;;)
{
err = read_header (stream, tarinfo, &header);
err = read_header (stream, tarinfo, &header, &extheader);
if (err || header == NULL)
goto leave;
print_header (header, es_stdout);
print_header (header, extheader, es_stdout);
if (skip_data (stream, tarinfo, header))
goto leave;
free_strlist (extheader);
extheader = NULL;
xfree (header);
header = NULL;
}
leave:
free_strlist (extheader);
xfree (header);
if (stream != es_stdin)
es_fclose (stream);
@ -383,14 +548,15 @@ gpgtar_list (const char *filename, int decrypt)
}
gpg_error_t
gpgtar_read_header (estream_t stream, tarinfo_t info, tar_header_t *r_header)
gpgtar_read_header (estream_t stream, tarinfo_t info,
tar_header_t *r_header, strlist_t *r_extheader)
{
return read_header (stream, info, r_header);
return read_header (stream, info, r_header, r_extheader);
}
void
gpgtar_print_header (tar_header_t header, estream_t out)
gpgtar_print_header (tar_header_t header, strlist_t extheader, estream_t out)
{
if (header && out)
print_header (header, out);
print_header (header, extheader, out);
}

7
tools/gpgtar.h
View File

@ -95,6 +95,8 @@ typedef enum
TF_DIRECTORY,
TF_FIFO,
TF_RESERVED,
TF_GEXTHDR, /* Global extended header. */
TF_EXTHDR, /* Extended header. */
TF_UNKNOWN, /* Needs to be treated as regular file. */
TF_NOTSUP /* Not supported (used with --create). */
} typeflag_t;
@ -140,8 +142,9 @@ gpg_error_t gpgtar_extract (const char *filename, int decrypt);
/*-- gpgtar-list.c --*/
gpg_error_t gpgtar_list (const char *filename, int decrypt);
gpg_error_t gpgtar_read_header (estream_t stream, tarinfo_t info,
tar_header_t *r_header);
void gpgtar_print_header (tar_header_t header, estream_t out);
tar_header_t *r_header, strlist_t *r_extheader);
void gpgtar_print_header (tar_header_t header, strlist_t extheader,
estream_t out);
#endif /*GPGTAR_H*/