Add unfinished gpgtar.

Collected changes and ports of bug fixes from stable.

tools/gpgtar-extract.c

@@ -0,0 +1,266 @@
+/* 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>
+
+#include "i18n.h"
+#include "../common/sysutils.h"
+#include "gpgtar.h"
+
+
+
+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:
+  es_fclose (outfp);
+  if (err && fname && outfp)
+    {
+      if (gnupg_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;
+
+  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 (gnupg_mkdir (fname, "-rwx------"))
+    {
+      err = gpg_error_from_syserror ();
+      log_error ("error creating directory `%s': %s\n",
+                 fname, gpg_strerror (err));
+    }
+
+ leave:
+  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 for `%s' - skipped\n", 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 *dirname = NULL;
+  int idx;
+
+  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;
+      if (errno != EEXIST && errno != ENOTDIR)
+        {
+          err = gpg_error_from_syserror ();
+          goto leave;
+        }
+    }
+  err = gpg_error_from_syserror ();
+
+ leave:
+  if (err)
+    {
+      log_error ("error creating an extract directory: %s\n",
+                 gpg_strerror (err));
+      xfree (dirname);
+      dirname = NULL;
+    }
+  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)
+    {
+      dirprefix = strrchr (filename, '/');
+      if (dirprefix)
+        dirprefix++;
+      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;  /* FIXME:  How can we enforce binary mode?  */
+
+  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;
+}