diff options
Diffstat (limited to 'tools/gpgtar-extract.c')
| -rw-r--r-- | tools/gpgtar-extract.c | 349 |
1 files changed, 349 insertions, 0 deletions
diff --git a/tools/gpgtar-extract.c b/tools/gpgtar-extract.c new file mode 100644 index 000000000..736c7fc4b --- /dev/null +++ b/tools/gpgtar-extract.c @@ -0,0 +1,349 @@ +/* gpgtar-extract.c - Extract from a TAR archive + * 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 <http://www.gnu.org/licenses/>. + */ + +#include <config.h> +#include <errno.h> +#include <stdio.h> +#include <stdlib.h> +#include <string.h> +#include <sys/types.h> +#include <sys/stat.h> +#include <unistd.h> +#include <assert.h> +#ifdef HAVE_W32_SYSTEM +# include <fcntl.h> /* for setmode() */ +#endif /*HAVE_W32_SYSTEM*/ + +#include "i18n.h" +#include "../common/sysutils.h" +#include "gpgtar.h" + +#ifndef GPG_ERR_LIMIT_REACHED +#define GPG_ERR_LIMIT_REACHED 183 +#endif + + +static gpg_error_t +extract_regular (estream_t stream, const char *dirname, + tar_header_t hdr) +{ + gpg_error_t err; + char record[RECORDSIZE]; + size_t n, nbytes, nwritten; + char *fname; + estream_t outfp = NULL; + + fname = strconcat (dirname, "/", hdr->name, NULL); + if (!fname) + { + err = gpg_error_from_syserror (); + log_error ("error creating filename: %s\n", gpg_strerror (err)); + goto leave; + } + else + err = 0; + + outfp = es_fopen (fname, "wb"); + if (!outfp) + { + err = gpg_error_from_syserror (); + log_error ("error creating `%s': %s\n", fname, gpg_strerror (err)); + goto leave; + } + + for (n=0; n < hdr->nrecords;) + { + err = read_record (stream, record); + if (err) + goto leave; + n++; + nbytes = (n < hdr->nrecords)? RECORDSIZE : (hdr->size % RECORDSIZE); + nwritten = es_fwrite (record, 1, nbytes, outfp); + if (nwritten != nbytes) + { + err = gpg_error_from_syserror (); + log_error ("error writing `%s': %s\n", fname, gpg_strerror (err)); + goto leave; + } + } + /* Fixme: Set permissions etc. */ + + leave: + if (!err && opt.verbose) + log_info ("extracted `%s'\n", fname); + es_fclose (outfp); + if (err && fname && outfp) + { + if (remove (fname)) + log_error ("error removing incomplete file `%s': %s\n", + fname, gpg_strerror (gpg_error_from_syserror ())); + } + xfree (fname); + return err; +} + + +static gpg_error_t +extract_directory (const char *dirname, tar_header_t hdr) +{ + gpg_error_t err; + char *fname; + size_t prefixlen; + + prefixlen = strlen (dirname) + 1; + fname = strconcat (dirname, "/", hdr->name, NULL); + if (!fname) + { + err = gpg_error_from_syserror (); + log_error ("error creating filename: %s\n", gpg_strerror (err)); + goto leave; + } + else + err = 0; + + if (fname[strlen (fname)-1] == '/') + fname[strlen (fname)-1] = 0; + + /* Note that we don't need to care about EEXIST because we always + extract into a new hierarchy. */ + if (gnupg_mkdir (fname, "-rwx------")) + { + err = gpg_error_from_syserror (); + if (gpg_err_code (err) == GPG_ERR_ENOENT) + { + /* Try to create the directory with parents but keep the + original error code in case of a failure. */ + char *p; + int rc = 0; + + for (p = fname+prefixlen; (p = strchr (p, '/')); p++) + { + *p = 0; + rc = gnupg_mkdir (fname, "-rwx------"); + *p = '/'; + if (rc) + break; + } + if (!rc && !gnupg_mkdir (fname, "-rwx------")) + err = 0; + } + if (err) + log_error ("error creating directory `%s': %s\n", + fname, gpg_strerror (err)); + } + + leave: + if (!err && opt.verbose) + log_info ("created `%s/'\n", fname); + xfree (fname); + return err; +} + + +static gpg_error_t +extract (estream_t stream, const char *dirname, tar_header_t hdr) +{ + 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, hdr); + else if (hdr->typeflag == TF_DIRECTORY) + err = extract_directory (dirname, hdr); + else + { + char record[RECORDSIZE]; + + log_info ("unsupported file type %d for `%s' - skipped\n", + (int)hdr->typeflag, hdr->name); + for (err = 0, n=0; !err && n < hdr->nrecords; n++) + err = read_record (stream, record); + } + return err; +} + + +/* Create a new directory to be used for extracting the tarball. + Returns the name of the directory which must be freed by the + caller. In case of an error a diagnostic is printed and NULL + returned. */ +static char * +create_directory (const char *dirprefix) +{ + gpg_error_t err = 0; + char *prefix_buffer = NULL; + char *dirname = NULL; + size_t n; + int idx; + + /* Remove common suffixes. */ + n = strlen (dirprefix); + if (n > 4 && (!compare_filenames (dirprefix + n - 4, EXTSEP_S "gpg") + || !compare_filenames (dirprefix + n - 4, EXTSEP_S "pgp") + || !compare_filenames (dirprefix + n - 4, EXTSEP_S "asc") + || !compare_filenames (dirprefix + n - 4, EXTSEP_S "pem") + || !compare_filenames (dirprefix + n - 4, EXTSEP_S "p7m") + || !compare_filenames (dirprefix + n - 4, EXTSEP_S "p7e"))) + { + prefix_buffer = xtrystrdup (dirprefix); + if (!prefix_buffer) + { + err = gpg_error_from_syserror (); + goto leave; + } + prefix_buffer[n-4] = 0; + dirprefix = prefix_buffer; + } + + + + for (idx=1; idx < 5000; idx++) + { + xfree (dirname); + dirname = xtryasprintf ("%s_%d_", dirprefix, idx); + if (!dirname) + { + err = gpg_error_from_syserror (); + goto leave; + } + if (!gnupg_mkdir (dirname, "-rwx------")) + goto leave; /* Ready. */ + if (errno != EEXIST && errno != ENOTDIR) + { + err = gpg_error_from_syserror (); + goto leave; + } + } + err = gpg_error (GPG_ERR_LIMIT_REACHED); + + leave: + if (err) + { + log_error ("error creating an extract directory: %s\n", + gpg_strerror (err)); + xfree (dirname); + dirname = NULL; + } + xfree (prefix_buffer); + return dirname; +} + + + +void +gpgtar_extract (const char *filename) +{ + gpg_error_t err; + estream_t stream; + tar_header_t header = NULL; + const char *dirprefix = NULL; + char *dirname = NULL; + + if (filename) + { + if (!strcmp (filename, "-")) + stream = es_stdin; + else + stream = es_fopen (filename, "rb"); + if (!stream) + { + err = gpg_error_from_syserror (); + log_error ("error opening `%s': %s\n", filename, gpg_strerror (err)); + return; + } + } + else + stream = es_stdin; + +#ifdef HAVE_DOSISH_SYSTEM + if (stream == es_stdin) + setmode (es_fileno (es_stdin), O_BINARY); +#endif + + if (filename && stream != es_stdin) + { + dirprefix = strrchr (filename, '/'); + if (dirprefix) + dirprefix++; + else + dirprefix = filename; + } + else if (opt.filename) + { + dirprefix = strrchr (opt.filename, '/'); + if (dirprefix) + dirprefix++; + else + dirprefix = opt.filename; + } + + if (!dirprefix || !*dirprefix) + dirprefix = "GPGARCH"; + + dirname = create_directory (dirprefix); + if (!dirname) + { + err = gpg_error (GPG_ERR_GENERAL); + goto leave; + } + + if (opt.verbose) + log_info ("extracting to `%s/'\n", dirname); + + for (;;) + { + header = gpgtar_read_header (stream); + if (!header) + goto leave; + + if (extract (stream, dirname, header)) + goto leave; + xfree (header); + header = NULL; + } + + + leave: + xfree (header); + xfree (dirname); + if (stream != es_stdin) + es_fclose (stream); + return; +} |