diff options
Diffstat (limited to 'tools/gpgtar-extract.c')
| -rw-r--r-- | tools/gpgtar-extract.c | 122 |
1 files changed, 80 insertions, 42 deletions
diff --git a/tools/gpgtar-extract.c b/tools/gpgtar-extract.c index 3da100c07..e9baada4e 100644 --- a/tools/gpgtar-extract.c +++ b/tools/gpgtar-extract.c @@ -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; + + name = hdr->name; + for (sl = exthdr; sl; sl = sl->next) + if (sl->flags == 1) + name = sl->d; - prefixlen = strlen (dirname) + 1; - fname = strconcat (dirname, "/", hdr->name, NULL); + 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' as 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) |