g13: First chunk of code to support dm-crypt.

* g13/call-syshelp.c, g13/call-syshelp.h: New.
* g13/g13-syshelp.c, g13/g13-syshelp.h: New.
* g13/sh-cmd.c: New.
* g13/sh-blockdev.c: New.
* g13/sh-exectool.c: New.
* g13/sh-dmcrypt.c: New.
* g13/Makefile.am (sbin_PROGRAMS): Add g13-syshelp.c
(g13_syshelp_SOURCES): New.
(g13_syshelp_LDADD): New.

* g13/g13.c (opts): Add option --type.
(g13_deinit_default_ctrl): New.
(main): Implement that option.  Call g13_deinit_default_ctrl.
* g13/g13.h (struct call_syshelp_s): New declaration.
(server_control_s): Add field syshelp_local.
* g13/keyblob.h (KEYBLOB_TAG_CREATED): New.
(KEYBLOB_TAG_ALGOSTR): New.
(KEYBLOB_TAG_HDRCOPY): New.
* g13/backend.c (be_parse_conttype_name): New.
(be_get_detached_name): Add CONTTYPE_DM_CRYPT.

Signed-off-by: Werner Koch <wk@gnupg.org>

1 files changed, 555 insertions, 0 deletions

diff --git a/g13/sh-cmd.c b/g13/sh-cmd.c
new file mode 100644
index 000000000..4ef37c105
--- /dev/null
+++ b/g13/sh-cmd.c
@@ -0,0 +1,555 @@
+/* sh-cmd.c - The Assuan server for g13-syshelp
+ * Copyright (C) 2015 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 <http://www.gnu.org/licenses/>.
+ */
+
+#include <config.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <stdarg.h>
+#include <errno.h>
+#include <assert.h>
+
+#include "g13-syshelp.h"
+#include <assuan.h>
+#include "i18n.h"
+#include "keyblob.h"
+
+
+/* Local data for this server module.  A pointer to this is stored in
+   the CTRL object of each connection.  */
+struct server_local_s
+{
+  /* The Assuan contect we are working on.  */
+  assuan_context_t assuan_ctx;
+
+  /* The malloced name of the device.  */
+  char *devicename;
+
+  /* A stream open for read of the device set by the DEVICE command or
+     NULL if no DEVICE command has been used.  */
+  estream_t devicefp;
+};
+
+
+
+
+/* Local prototypes.  */
+
+
+
+
+/*
+   Helper functions.
+ */
+
+/* Set an error and a description.  */
+#define set_error(e,t) assuan_set_error (ctx, gpg_error (e), (t))
+#define set_error_fail_cmd() set_error (GPG_ERR_NOT_INITIALIZED, \
+                                        "not called via userv or unknown user")
+
+
+/* Skip over options.  Blanks after the options are also removed.  */
+static char *
+skip_options (const char *line)
+{
+  while (spacep (line))
+    line++;
+  while ( *line == '-' && line[1] == '-' )
+    {
+      while (*line && !spacep (line))
+        line++;
+      while (spacep (line))
+        line++;
+    }
+  return (char*)line;
+}
+
+
+/* Check whether the option NAME appears in LINE.  */
+/* static int */
+/* has_option (const char *line, const char *name) */
+/* { */
+/*   const char *s; */
+/*   int n = strlen (name); */
+
+/*   s = strstr (line, name); */
+/*   if (s && s >= skip_options (line)) */
+/*     return 0; */
+/*   return (s && (s == line || spacep (s-1)) && (!s[n] || spacep (s+n))); */
+/* } */
+
+
+/* Helper to print a message while leaving a command.  */
+static gpg_error_t
+leave_cmd (assuan_context_t ctx, gpg_error_t err)
+{
+  if (err)
+    {
+      const char *name = assuan_get_command_name (ctx);
+      if (!name)
+        name = "?";
+      if (gpg_err_source (err) == GPG_ERR_SOURCE_DEFAULT)
+        log_error ("command '%s' failed: %s\n", name,
+                   gpg_strerror (err));
+      else
+        log_error ("command '%s' failed: %s <%s>\n", name,
+                   gpg_strerror (err), gpg_strsource (err));
+    }
+  return err;
+}
+
+
+
+
+/* The handler for Assuan OPTION commands.  */
+static gpg_error_t
+option_handler (assuan_context_t ctx, const char *key, const char *value)
+{
+  ctrl_t ctrl = assuan_get_pointer (ctx);
+  gpg_error_t err = 0;
+
+  (void)ctrl;
+  (void)key;
+  (void)value;
+
+  if (ctrl->fail_all_cmds)
+    err = set_error_fail_cmd ();
+  else
+    err = gpg_error (GPG_ERR_UNKNOWN_OPTION);
+
+  return err;
+}
+
+
+/* The handler for an Assuan RESET command.  */
+static gpg_error_t
+reset_notify (assuan_context_t ctx, char *line)
+{
+  ctrl_t ctrl = assuan_get_pointer (ctx);
+
+  (void)line;
+
+  xfree (ctrl->server_local->devicename);
+  ctrl->server_local->devicename = NULL;
+  es_fclose (ctrl->server_local->devicefp);
+  ctrl->server_local->devicefp = NULL;
+  ctrl->devti = NULL;
+
+  assuan_close_input_fd (ctx);
+  assuan_close_output_fd (ctx);
+  return 0;
+}
+
+
+static const char hlp_device[] =
+  "DEVICE <name>\n"
+  "\n"
+  "Set the device used by further commands.\n"
+  "A device name or a PARTUUID string may be used.";
+static gpg_error_t
+cmd_device (assuan_context_t ctx, char *line)
+{
+  ctrl_t ctrl = assuan_get_pointer (ctx);
+  gpg_error_t err = 0;
+  tab_item_t ti;
+  estream_t fp = NULL;
+
+  /* strcpy (line, "/dev/sdb1"); /\* FIXME *\/ */
+  line = skip_options (line);
+
+  /* Always close an open device stream of this session. */
+  xfree (ctrl->server_local->devicename);
+  ctrl->server_local->devicename = NULL;
+  es_fclose (ctrl->server_local->devicefp);
+  ctrl->server_local->devicefp = NULL;
+
+  /* Are we allowed to use the given device?  */
+  for (ti=ctrl->client.tab; ti; ti = ti->next)
+    if (!strcmp (line, ti->blockdev))
+      break;
+  if (!ti)
+    {
+      set_error (GPG_ERR_EACCES, "device not configured for user");
+      goto leave;
+    }
+
+  ctrl->server_local->devicename = xtrystrdup (line);
+  if (!ctrl->server_local->devicename)
+    {
+      err = gpg_error_from_syserror ();
+      goto leave;
+    }
+
+
+  /* Check whether we have permissions to open the device and keep an
+     FD open.  */
+  fp = es_fopen (ctrl->server_local->devicename, "rb");
+  if (!fp)
+    {
+      err = gpg_error_from_syserror ();
+      log_error ("error opening '%s': %s\n",
+                 ctrl->server_local->devicename, gpg_strerror (err));
+      goto leave;
+    }
+
+  es_fclose (ctrl->server_local->devicefp);
+  ctrl->server_local->devicefp = fp;
+  fp = NULL;
+  ctrl->devti = ti;
+
+ leave:
+  es_fclose (fp);
+  if (err)
+    {
+      xfree (ctrl->server_local->devicename);
+      ctrl->server_local->devicename = NULL;
+      ctrl->devti = NULL;
+    }
+  return leave_cmd (ctx, err);
+}
+
+
+static const char hlp_create[] =
+  "CREATE <type>\n"
+  "\n"
+  "Create a new encrypted partition on the current device.\n"
+  "<type> must be \"dm-crypt\" for now.";
+static gpg_error_t
+cmd_create (assuan_context_t ctx, char *line)
+{
+  ctrl_t ctrl = assuan_get_pointer (ctx);
+  gpg_error_t err = 0;
+
+  line = skip_options (line);
+
+  if (strcmp (line, "dm-crypt"))
+    {
+      err = set_error (GPG_ERR_INV_ARG, "Type must be \"dm-crypt\"");
+      goto leave;
+    }
+
+  if (!ctrl->server_local->devicename
+      || !ctrl->server_local->devicefp
+      || !ctrl->devti)
+    {
+      err = set_error (GPG_ERR_ENOENT, "No device has been set");
+      goto leave;
+    }
+
+  err = sh_is_empty_partition (ctrl->server_local->devicename);
+  if (err)
+    {
+      assuan_set_error (ctx, err, "Partition is not empty");
+      goto leave;
+    }
+
+  err = sh_dmcrypt_create_container (ctrl,
+                                     ctrl->server_local->devicename,
+                                     ctrl->server_local->devicefp);
+
+
+
+
+ leave:
+  return leave_cmd (ctx, err);
+}
+
+
+
+static const char hlp_getinfo[] =
+  "GETINFO <what>\n"
+  "\n"
+  "Multipurpose function to return a variety of information.\n"
+  "Supported values for WHAT are:\n"
+  "\n"
+  "  version     - Return the version of the program.\n"
+  "  pid         - Return the process id of the server.\n"
+  "  showtab     - Show the table for the user.";
+static gpg_error_t
+cmd_getinfo (assuan_context_t ctx, char *line)
+{
+  ctrl_t ctrl = assuan_get_pointer (ctx);
+  gpg_error_t err = 0;
+  char *buf;
+
+  if (!strcmp (line, "version"))
+    {
+      const char *s = PACKAGE_VERSION;
+      err = assuan_send_data (ctx, s, strlen (s));
+    }
+  else if (!strcmp (line, "pid"))
+    {
+      char numbuf[50];
+
+      snprintf (numbuf, sizeof numbuf, "%lu", (unsigned long)getpid ());
+      err = assuan_send_data (ctx, numbuf, strlen (numbuf));
+    }
+  else if (!strncmp (line, "getsz", 5))
+    {
+      unsigned long long nblocks;
+      err = sh_blockdev_getsz (line+6, &nblocks);
+      if (!err)
+        log_debug ("getsz=%llu\n", nblocks);
+    }
+  else if (!strcmp (line, "showtab"))
+    {
+      tab_item_t ti;
+
+      for (ti=ctrl->client.tab; !err && ti; ti = ti->next)
+        {
+          buf = es_bsprintf ("%s %s%s %s %s%s\n",
+                             ctrl->client.uname,
+                             *ti->blockdev=='/'? "":"partuuid=",
+                             ti->blockdev,
+                             ti->label? ti->label : "-",
+                             ti->mountpoint? " ":"",
+                             ti->mountpoint? ti->mountpoint:"");
+          if (!buf)
+            err = gpg_error_from_syserror ();
+          else
+            {
+              err = assuan_send_data (ctx, buf, strlen (buf));
+              if (!err)
+                err = assuan_send_data (ctx, NULL, 0); /* Flush  */
+            }
+          xfree (buf);
+        }
+    }
+  else
+    err = set_error (GPG_ERR_ASS_PARAMETER, "unknown value for WHAT");
+
+  return leave_cmd (ctx, err);
+}
+
+
+/* This command handler is used for all commands if this process has
+   not been started as expected.  */
+static gpg_error_t
+fail_command (assuan_context_t ctx, char *line)
+{
+  gpg_error_t err;
+  const char *name = assuan_get_command_name (ctx);
+
+  (void)line;
+
+  if (!name)
+    name = "?";
+
+  err = set_error_fail_cmd ();
+  log_error ("command '%s' failed: %s\n", name, gpg_strerror (err));
+  return err;
+}
+
+
+/* Tell the Assuan library about our commands.  */
+static int
+register_commands (assuan_context_t ctx, int fail_all)
+{
+  static struct {
+    const char *name;
+    assuan_handler_t handler;
+    const char * const help;
+  } table[] =  {
+    { "DEVICE",        cmd_device, hlp_device },
+    { "CREATE",        cmd_create, hlp_create },
+    { "INPUT",         NULL },
+    { "OUTPUT",        NULL },
+    { "GETINFO",       cmd_getinfo, hlp_getinfo },
+    { NULL }
+  };
+  gpg_error_t err;
+  int i;
+
+  for (i=0; table[i].name; i++)
+    {
+      err = assuan_register_command (ctx, table[i].name,
+                                     fail_all ? fail_command : table[i].handler,
+                                     table[i].help);
+      if (err)
+        return err;
+    }
+  return 0;
+}
+
+
+/* Startup the server.  */
+gpg_error_t
+syshelp_server (ctrl_t ctrl)
+{
+  gpg_error_t err;
+  assuan_fd_t filedes[2];
+  assuan_context_t ctx = NULL;
+
+  /* We use a pipe based server so that we can work from scripts.
+     assuan_init_pipe_server will automagically detect when we are
+     called with a socketpair and ignore FILEDES in this case. */
+  filedes[0] = assuan_fdopen (0);
+  filedes[1] = assuan_fdopen (1);
+  err = assuan_new (&ctx);
+  if (err)
+    {
+      log_error ("failed to allocate an Assuan context: %s\n",
+                 gpg_strerror (err));
+      goto leave;
+    }
+
+  err = assuan_init_pipe_server (ctx, filedes);
+  if (err)
+    {
+      log_error ("failed to initialize the server: %s\n", gpg_strerror (err));
+      goto leave;
+    }
+
+  err = register_commands (ctx, 0 /*FIXME:ctrl->fail_all_cmds*/);
+  if (err)
+    {
+      log_error ("failed to the register commands with Assuan: %s\n",
+                 gpg_strerror (err));
+      goto leave;
+    }
+
+  assuan_set_pointer (ctx, ctrl);
+
+  {
+    char *tmp = xtryasprintf ("G13-syshelp %s ready to serve requests "
+                              "from %lu(%s)",
+                              PACKAGE_VERSION,
+                              (unsigned long)ctrl->client.uid,
+                              ctrl->client.uname);
+    if (tmp)
+      {
+        assuan_set_hello_line (ctx, tmp);
+        xfree (tmp);
+      }
+  }
+
+  assuan_register_reset_notify (ctx, reset_notify);
+  assuan_register_option_handler (ctx, option_handler);
+
+  ctrl->server_local = xtrycalloc (1, sizeof *ctrl->server_local);
+  if (!ctrl->server_local)
+    {
+      err = gpg_error_from_syserror ();
+      goto leave;
+    }
+  ctrl->server_local->assuan_ctx = ctx;
+
+  while ( !(err = assuan_accept (ctx)) )
+    {
+      err = assuan_process (ctx);
+      if (err)
+        log_info ("Assuan processing failed: %s\n", gpg_strerror (err));
+    }
+  if (err == -1)
+    err = 0;
+  else
+    log_info ("Assuan accept problem: %s\n", gpg_strerror (err));
+
+ leave:
+  reset_notify (ctx, NULL);  /* Release all items hold by SERVER_LOCAL.  */
+  if (ctrl->server_local)
+    {
+      xfree (ctrl->server_local);
+      ctrl->server_local = NULL;
+    }
+
+  assuan_release (ctx);
+  return err;
+}
+
+
+gpg_error_t
+sh_encrypt_keyblob (ctrl_t ctrl, const void *keyblob, size_t keybloblen,
+                    char **r_enckeyblob, size_t *r_enckeybloblen)
+{
+  assuan_context_t ctx = ctrl->server_local->assuan_ctx;
+  gpg_error_t err;
+  unsigned char *enckeyblob;
+  size_t enckeybloblen;
+
+  *r_enckeyblob = NULL;
+
+  /* Send the plaintext.  */
+  err = g13_status (ctrl, STATUS_PLAINTEXT_FOLLOWS, NULL);
+  if (err)
+    return err;
+  assuan_begin_confidential (ctx);
+  err = assuan_send_data (ctx, keyblob, keybloblen);
+  if (!err)
+    err = assuan_send_data (ctx, NULL, 0);
+  assuan_end_confidential (ctx);
+  if (!err)
+    err = assuan_write_line (ctx, "END");
+  if (err)
+    {
+      log_error (_("error sending data: %s\n"), gpg_strerror (err));
+      return err;
+    }
+
+  /* Inquire the ciphertext.  */
+  err = assuan_inquire (ctx, "ENCKEYBLOB",
+                        &enckeyblob, &enckeybloblen, 16 * 1024);
+  if (err)
+    {
+      log_error (_("assuan_inquire failed: %s\n"), gpg_strerror (err));
+      return err;
+    }
+
+  *r_enckeyblob = enckeyblob;
+  *r_enckeybloblen = enckeybloblen;
+  return 0;
+}
+
+
+/* Send a status line with status ID NO.  The arguments are a list of
+   strings terminated by a NULL argument.  */
+gpg_error_t
+g13_status (ctrl_t ctrl, int no, ...)
+{
+  gpg_error_t err = 0;
+  va_list arg_ptr;
+  const char *text;
+
+  va_start (arg_ptr, no);
+
+  if (1)
+    {
+      assuan_context_t ctx = ctrl->server_local->assuan_ctx;
+      char buf[950], *p;
+      size_t n;
+
+      p = buf;
+      n = 0;
+      while ( (text = va_arg (arg_ptr, const char *)) )
+        {
+          if (n)
+            {
+              *p++ = ' ';
+              n++;
+            }
+          for ( ; *text && n < DIM (buf)-2; n++)
+            *p++ = *text++;
+        }
+      *p = 0;
+      err = assuan_write_status (ctx, get_status_string (no), buf);
+    }
+
+  va_end (arg_ptr);
+  return err;
+}