summaryrefslogtreecommitdiffstats
path: root/g13/keyblob.c
diff options
context:
space:
mode:
Diffstat (limited to '')
-rw-r--r--g13/keyblob.c207
1 files changed, 207 insertions, 0 deletions
diff --git a/g13/keyblob.c b/g13/keyblob.c
new file mode 100644
index 0000000..1fb9be7
--- /dev/null
+++ b/g13/keyblob.c
@@ -0,0 +1,207 @@
+/* keyblob.c - Keyblob parser and builder.
+ * Copyright (C) 2009 Free Software Foundation, Inc.
+ * Copyright (C) 2015-2016 Werner Koch
+ *
+ * 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/>.
+ */
+
+#include <config.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <errno.h>
+#include <unistd.h>
+#include <sys/stat.h>
+#include <assert.h>
+
+#include "g13.h"
+#include "mount.h"
+
+#include "keyblob.h"
+#include "../common/sysutils.h"
+#include "../common/host2net.h"
+
+
+/* Parse the header prefix and return the length of the entire header. */
+static gpg_error_t
+parse_header (const char *filename,
+ const unsigned char *packet, size_t packetlen,
+ size_t *r_headerlen)
+{
+ unsigned int len;
+
+ if (packetlen != 32)
+ return gpg_error (GPG_ERR_BUG);
+
+ len = buf32_to_uint (packet+2);
+ if (packet[0] != (0xc0|61) || len < 26
+ || memcmp (packet+6, "GnuPG/G13", 10))
+ {
+ log_error ("file '%s' is not valid container\n", filename);
+ return gpg_error (GPG_ERR_INV_OBJ);
+ }
+ if (packet[16] != 1)
+ {
+ log_error ("unknown version %u of container '%s'\n",
+ (unsigned int)packet[16], filename);
+ return gpg_error (GPG_ERR_INV_OBJ);
+ }
+ if (packet[17] || packet[18]
+ || packet[26] || packet[27] || packet[28] || packet[29]
+ || packet[30] || packet[31])
+ log_info ("WARNING: unknown meta information in '%s'\n", filename);
+ if (packet[19])
+ log_info ("WARNING: OS flag is not supported in '%s'\n", filename);
+ if (packet[24] > 1 )
+ log_info ("Note: meta data copies in '%s' are ignored\n", filename);
+
+ len = buf32_to_uint (packet+20);
+
+ /* Do a basic sanity check on the length. */
+ if (len < 32 || len > 1024*1024)
+ {
+ log_error ("bad length given in container '%s'\n", filename);
+ return gpg_error (GPG_ERR_INV_OBJ);
+ }
+
+ *r_headerlen = len;
+ return 0;
+}
+
+
+/* Read the prefix of the keyblob and do some basic parsing. On
+ success returns an open estream file at R_FP and the length of the
+ header at R_HEADERLEN. */
+static gpg_error_t
+read_keyblob_prefix (const char *filename, estream_t *r_fp, size_t *r_headerlen)
+{
+ gpg_error_t err;
+ estream_t fp;
+ unsigned char packet[32];
+
+ *r_fp = NULL;
+
+ fp = es_fopen (filename, "rb");
+ if (!fp)
+ {
+ err = gpg_error_from_syserror ();
+ log_error ("error reading '%s': %s\n", filename, gpg_strerror (err));
+ return err;
+ }
+
+ /* Read the header. It is defined as 32 bytes thus we read it in one go. */
+ if (es_fread (packet, 32, 1, fp) != 1)
+ {
+ err = gpg_error_from_syserror ();
+ log_error ("error reading the header of '%s': %s\n",
+ filename, gpg_strerror (err));
+ es_fclose (fp);
+ return err;
+ }
+
+ err = parse_header (filename, packet, 32, r_headerlen);
+ if (err)
+ es_fclose (fp);
+ else
+ *r_fp = fp;
+
+ return err;
+}
+
+
+
+/*
+ * Test whether the container with name FILENAME is a suitable G13
+ * container. This function may even be called on a mounted
+ * container.
+ */
+gpg_error_t
+g13_is_container (ctrl_t ctrl, const char *filename)
+{
+ gpg_error_t err;
+ estream_t fp = NULL;
+ size_t dummy;
+
+ (void)ctrl;
+
+ /* Read just the prefix of the header. */
+ err = read_keyblob_prefix (filename, &fp, &dummy);
+ if (!err)
+ es_fclose (fp);
+ return err;
+}
+
+
+/*
+ * Read the keyblob at FILENAME. The caller should have acquired a
+ * lockfile and checked that the file exists.
+ */
+gpg_error_t
+g13_keyblob_read (const char *filename,
+ void **r_enckeyblob, size_t *r_enckeybloblen)
+{
+ gpg_error_t err;
+ estream_t fp = NULL;
+ size_t headerlen = 0;
+ size_t msglen;
+ void *msg = NULL;
+
+ *r_enckeyblob = NULL;
+ *r_enckeybloblen = 0;
+
+ err = read_keyblob_prefix (filename, &fp, &headerlen);
+ if (err)
+ goto leave;
+
+ if (opt.verbose)
+ log_info ("header length of '%s' is %zu\n", filename, headerlen);
+
+ /* Read everything including the padding. We should eventually do a
+ regular OpenPGP parsing to detect the padding packet and pass
+ only the actual used OpenPGP data to the engine. This is in
+ particular required when supporting CMS which will be
+ encapsulated in an OpenPGP packet. */
+ assert (headerlen >= 32);
+ msglen = headerlen - 32;
+ if (!msglen)
+ {
+ err = gpg_error (GPG_ERR_NO_DATA);
+ goto leave;
+ }
+ msg = xtrymalloc (msglen);
+ if (!msglen)
+ {
+ err = gpg_error_from_syserror ();
+ goto leave;
+ }
+ if (es_fread (msg, msglen, 1, fp) != 1)
+ {
+ err = gpg_error_from_syserror ();
+ log_error ("error reading keyblob of '%s': %s\n",
+ filename, gpg_strerror (err));
+ goto leave;
+ }
+
+ *r_enckeyblob = msg;
+ msg = NULL;
+ *r_enckeybloblen = msglen;
+
+ leave:
+ xfree (msg);
+ es_fclose (fp);
+
+ return err;
+}