/* 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.
*
* GnuPG is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 3 of the License, or
* (at your option) any later version.
*
* GnuPG is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* 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>
#include <errno.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include "../common/i18n.h"
#include <gpg-error.h>
#include "gpgtar.h"
#include "../common/exechelp.h"
#include "../common/sysutils.h"
#include "../common/ccparray.h"
static unsigned long long
parse_xoctal (const void *data, size_t length, const char *filename)
{
const unsigned char *p = data;
unsigned long long value;
if (!length)
value = 0;
else if ( (*p & 0x80))
{
/* Binary format. */
value = (*p++ & 0x7f);
while (--length)
{
value <<= 8;
value |= *p++;
}
}
else
{
/* Octal format */
value = 0;
/* Skip leading spaces and zeroes. */
for (; length && (*p == ' ' || *p == '0'); length--, p++)
;
for (; length && *p; length--, p++)
{
if (*p >= '0' && *p <= '7')
{
value <<= 3;
value += (*p - '0');
}
else
{
log_error ("%s: invalid octal number encountered - assuming 0\n",
filename);
value = 0;
break;
}
}
}
return value;
}
static tar_header_t
parse_header (const void *record, const char *filename, tarinfo_t info)
{
const struct ustar_raw_header *raw = record;
size_t n, namelen, prefixlen;
tar_header_t header;
int use_prefix;
int anyerror = 0;
info->headerblock = info->nblocks - 1;
use_prefix = (!memcmp (raw->magic, "ustar", 5)
&& (raw->magic[5] == ' ' || !raw->magic[5]));
for (namelen=0; namelen < sizeof raw->name && raw->name[namelen]; namelen++)
;
if (namelen == sizeof raw->name)
{
log_info ("%s: warning: name not terminated by a nul\n", filename);
anyerror = 1;
}
for (n=namelen+1; n < sizeof raw->name; n++)
if (raw->name[n])
{
log_info ("%s: warning: garbage after name\n", filename);
anyerror = 1;
break;
}
if (use_prefix && raw->prefix[0])
{
for (prefixlen=0; (prefixlen < sizeof raw->prefix
&& raw->prefix[prefixlen]); prefixlen++)
;
if (prefixlen == sizeof raw->prefix)
log_info ("%s: warning: prefix not terminated by a nul (block %llu)\n",
filename, info->headerblock);
for (n=prefixlen+1; n < sizeof raw->prefix; n++)
if (raw->prefix[n])
{
log_info ("%s: warning: garbage after prefix\n", filename);
anyerror = 1;
break;
}
}
else
prefixlen = 0;
header = xtrycalloc (1, sizeof *header + prefixlen + 1 + namelen);
if (!header)
{
log_error ("%s: error allocating header: %s\n",
filename, gpg_strerror (gpg_error_from_syserror ()));
return NULL;
}
if (prefixlen)
{
n = prefixlen;
memcpy (header->name, raw->prefix, n);
if (raw->prefix[n-1] != '/')
header->name[n++] = '/';
}
else
n = 0;
memcpy (header->name+n, raw->name, namelen);
header->name[n+namelen] = 0;
header->mode = parse_xoctal (raw->mode, sizeof raw->mode, filename);
header->uid = parse_xoctal (raw->uid, sizeof raw->uid, filename);
header->gid = parse_xoctal (raw->gid, sizeof raw->gid, filename);
header->size = parse_xoctal (raw->size, sizeof raw->size, filename);
header->mtime = parse_xoctal (raw->mtime, sizeof raw->mtime, filename);
/* checksum = */
switch (raw->typeflag[0])
{
case '0': header->typeflag = TF_REGULAR; break;
case '1': header->typeflag = TF_HARDLINK; break;
case '2': header->typeflag = TF_SYMLINK; break;
case '3': header->typeflag = TF_CHARDEV; break;
case '4': header->typeflag = TF_BLOCKDEV; break;
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_EXTHDR
|| header->typeflag == TF_UNKNOWN)
header->nrecords = (header->size + RECORDSIZE-1)/RECORDSIZE;
else
header->nrecords = 0;
if (anyerror)
{
log_info ("%s: header block %llu is corrupt"
" (size=%llu type=%d nrec=%llu)\n",
filename, info->headerblock,
header->size, header->typeflag, header->nrecords);
/* log_printhex (record, RECORDSIZE, " "); */
}
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 (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, 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)
return err;
info->nblocks++;
for (i=0; i < RECORDSIZE && !record[i]; i++)
;
if (i == RECORDSIZE)
{
/* All zero header - check whether it is the first part of an
end of archive mark. */
err = read_record (stream, record);
if (err)
return err;
info->nblocks++;
for (i=0; i < RECORDSIZE && !record[i]; i++)
;
if (i != RECORDSIZE)
log_info ("%s: warning: skipping empty header\n",
es_fname_get (stream));
else
{
/* End of archive - FIXME: we might want to check for garbage. */
*r_header = NULL;
return 0;
}
}
*r_header = parse_header (record, es_fname_get (stream), info);
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);
}
/* Skip the data records according to HEADER. Prints an error message
on error and return -1. */
static int
skip_data (estream_t stream, tarinfo_t info, tar_header_t header)
{
char record[RECORDSIZE];
unsigned long long n;
for (n=0; n < header->nrecords; n++)
{
if (read_record (stream, record))
return -1;
info->nblocks++;
}
return 0;
}
static void
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)
{
case TF_REGULAR: *modestr = '-'; break;
case TF_HARDLINK: *modestr = 'h'; break;
case TF_SYMLINK: *modestr = 'l'; break;
case TF_CHARDEV: *modestr = 'c'; break;
case TF_BLOCKDEV: *modestr = 'b'; break;
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;
}
for (mask = 0400, i = 0; i < 9; i++, mask >>= 1)
modestr[1+i] = (header->mode & mask)? "rwxrwxrwx"[i]:'-';
if ((header->typeflag & 04000))
modestr[3] = modestr[3] == 'x'? 's':'S';
if ((header->typeflag & 02000))
modestr[6] = modestr[6] == 'x'? 's':'S';
if ((header->typeflag & 01000))
modestr[9] = modestr[9] == 'x'? 't':'T';
modestr[10] = 0;
/* 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),
name,
linkname? " -> " : "",
linkname? linkname : "");
}
/* List the tarball FILENAME or, if FILENAME is NULL, the tarball read
from stdin. */
gpg_error_t
gpgtar_list (const char *filename, int decrypt)
{
gpg_error_t err;
estream_t stream = NULL;
tar_header_t header = NULL;
strlist_t extheader = NULL;
struct tarinfo_s tarinfo_buffer;
tarinfo_t tarinfo = &tarinfo_buffer;
pid_t pid = (pid_t)(-1);
memset (&tarinfo_buffer, 0, sizeof tarinfo_buffer);
if (decrypt)
{
strlist_t arg;
ccparray_t ccp;
int except[2] = { -1, -1 };
const char **argv;
ccparray_init (&ccp, 0);
if (opt.batch)
ccparray_put (&ccp, "--batch");
if (opt.require_compliance)
ccparray_put (&ccp, "--require-compliance");
if (opt.status_fd != -1)
{
static char tmpbuf[40];
snprintf (tmpbuf, sizeof tmpbuf, "--status-fd=%d", opt.status_fd);
ccparray_put (&ccp, tmpbuf);
except[0] = opt.status_fd;
}
ccparray_put (&ccp, "--output");
ccparray_put (&ccp, "-");
ccparray_put (&ccp, "--decrypt");
for (arg = opt.gpg_arguments; arg; arg = arg->next)
ccparray_put (&ccp, arg->d);
if (filename)
{
ccparray_put (&ccp, "--");
ccparray_put (&ccp, filename);
}
ccparray_put (&ccp, NULL);
argv = ccparray_get (&ccp, NULL);
if (!argv)
{
err = gpg_error_from_syserror ();
goto leave;
}
err = gnupg_spawn_process (opt.gpg_program, argv,
except[0] == -1? NULL : except,
NULL,
((filename? 0 : GNUPG_SPAWN_KEEP_STDIN)
| GNUPG_SPAWN_KEEP_STDERR),
NULL, &stream, NULL, &pid);
xfree (argv);
if (err)
goto leave;
es_set_binary (stream);
}
else if (filename) /* No decryption requested. */
{
if (!strcmp (filename, "-"))
stream = es_stdin;
else
stream = es_fopen (filename, "rb,sysopen");
if (!stream)
{
err = gpg_error_from_syserror ();
log_error ("error opening '%s': %s\n", filename, gpg_strerror (err));
goto leave;
}
if (stream == es_stdin)
es_set_binary (es_stdin);
}
else
{
stream = es_stdin;
es_set_binary (es_stdin);
}
for (;;)
{
err = read_header (stream, tarinfo, &header, &extheader);
if (err || header == NULL)
goto leave;
print_header (header, extheader, es_stdout);
if (skip_data (stream, tarinfo, header))
goto leave;
free_strlist (extheader);
extheader = NULL;
xfree (header);
header = NULL;
}
if (pid != (pid_t)(-1))
{
int exitcode;
err = es_fclose (stream);
stream = NULL;
if (err)
log_error ("error closing pipe: %s\n", gpg_strerror (err));
else
{
err = gnupg_wait_process (opt.gpg_program, pid, 1, &exitcode);
if (err)
log_error ("running %s failed (exitcode=%d): %s",
opt.gpg_program, exitcode, gpg_strerror (err));
gnupg_release_process (pid);
pid = (pid_t)(-1);
}
}
leave:
free_strlist (extheader);
xfree (header);
if (stream != es_stdin)
es_fclose (stream);
return err;
}
gpg_error_t
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, r_extheader);
}
void
gpgtar_print_header (tar_header_t header, strlist_t extheader, estream_t out)
{
if (header && out)
print_header (header, extheader, out);
}