/* engine.c - GPGME engine support.

   Copyright (C) 2000 Werner Koch (dd9jn)

   Copyright (C) 2001, 2002, 2003, 2004, 2006, 2009, 2010 g10 Code GmbH

   This file is part of GPGME.

   GPGME is free software; you can redistribute it and/or modify it

   under the terms of the GNU Lesser General Public License as

   published by the Free Software Foundation; either version 2.1 of

   the License, or (at your option) any later version.

   GPGME 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

   Lesser General Public License for more details.

   You should have received a copy of the GNU Lesser General Public

   License along with this program; if not, see <https://www.gnu.org/licenses/>.

*/

#ifdef HAVE_CONFIG_H

#include <config.h>

#endif

#include <stdlib.h>

#include <string.h>

#include <errno.h>

#include <assert.h>

#include "gpgme.h"

#include "util.h"

#include "sema.h"

#include "ops.h"

#include "debug.h"

#include "engine.h"

#include "engine-backend.h"

struct engine

{

  struct engine_ops *ops;

  void *engine;

};

static struct engine_ops *engine_ops[] =

  {

    &_gpgme_engine_ops_gpg,		/* OpenPGP.  */

    &_gpgme_engine_ops_gpgsm,		/* CMS.  */

    &_gpgme_engine_ops_gpgconf,		/* gpg-conf.  */

    &_gpgme_engine_ops_assuan,		/* Low-Level Assuan.  */

    &_gpgme_engine_ops_g13,		/* Crypto VFS.  */

#ifdef ENABLE_UISERVER

    &_gpgme_engine_ops_uiserver,	/* UI-Server.  */

#else

    NULL,

#endif

    &_gpgme_engine_ops_spawn

  };

/* The engine info.  */

static gpgme_engine_info_t engine_info;

DEFINE_STATIC_LOCK (engine_info_lock);

/* If non-NULL, the minimal version required for all engines.  */

static char *engine_minimal_version;

/* Get the file name of the engine for PROTOCOL.  */

static const char *

engine_get_file_name (gpgme_protocol_t proto)

{

  if (proto > DIM (engine_ops))

    return NULL;

  if (engine_ops[proto] && engine_ops[proto]->get_file_name)

    return (*engine_ops[proto]->get_file_name) ();

  else

    return NULL;

}

/* Get the standard home dir of the engine for PROTOCOL.  */

static const char *

engine_get_home_dir (gpgme_protocol_t proto)

{

  if (proto > DIM (engine_ops))

    return NULL;

  if (engine_ops[proto] && engine_ops[proto]->get_home_dir)

    return (*engine_ops[proto]->get_home_dir) ();

  else

    return NULL;

}

/* Get a malloced string containing the version number of the engine

 * for PROTOCOL.  If this function returns NULL for a valid protocol,

 * it should be assumed that the engine is a pseudo engine. */

static char *

engine_get_version (gpgme_protocol_t proto, const char *file_name)

{

  if (proto > DIM (engine_ops))

    return NULL;

  if (engine_ops[proto] && engine_ops[proto]->get_version)

    return (*engine_ops[proto]->get_version) (file_name);

  else

    return NULL;

}

/* Get the required version number of the engine for PROTOCOL.  This

 * may be NULL. */

static const char *

engine_get_req_version (gpgme_protocol_t proto)

{

  if (proto > DIM (engine_ops))

    return NULL;

  if (engine_ops[proto] && engine_ops[proto]->get_req_version)

    return (*engine_ops[proto]->get_req_version) ();

  else

    return NULL;

}

/* Verify the version requirement for the engine for PROTOCOL.  */

gpgme_error_t

gpgme_engine_check_version (gpgme_protocol_t proto)

{

  gpgme_error_t err;

  gpgme_engine_info_t info;

  int result;

  LOCK (engine_info_lock);

  info = engine_info;

  if (!info)

    {

      /* Make sure it is initialized.  */

      UNLOCK (engine_info_lock);

      err = gpgme_get_engine_info (&info;;

      if (err)

	return err;

      LOCK (engine_info_lock);

    }

  while (info && info->protocol != proto)

    info = info->next;

  if (!info)

    result = 0;

  else

    result = _gpgme_compare_versions (info->version,

				      info->req_version);

  UNLOCK (engine_info_lock);

  return result ? 0 : trace_gpg_error (GPG_ERR_INV_ENGINE);

}

/* Release the engine info INFO.  */

void

_gpgme_engine_info_release (gpgme_engine_info_t info)

{

  while (info)

    {

      gpgme_engine_info_t next_info = info->next;

      if (info->file_name)

        free (info->file_name);

      if (info->home_dir)

	free (info->home_dir);

      if (info->version)

	free (info->version);

      free (info);

      info = next_info;

    }

}

/* This is an internal function to set a mimimal required version.

 * This function must only be called by gpgme_set_global_flag.

 * Returns 0 on success.  */

int

_gpgme_set_engine_minimal_version (const char *value)

{

  free (engine_minimal_version);

  if (value)

    {

      engine_minimal_version = strdup (value);

      return !engine_minimal_version;

    }

  else

    {

      engine_minimal_version = NULL;

      return 0;

    }

}

/* Get the information about the configured and installed engines.  A

   pointer to the first engine in the statically allocated linked list

   is returned in *INFO.  If an error occurs, it is returned.  The

   returned data is valid until the next gpgme_set_engine_info.  */

gpgme_error_t

gpgme_get_engine_info (gpgme_engine_info_t *info)

{

  gpgme_error_t err;

  LOCK (engine_info_lock);

  if (!engine_info)

    {

      gpgme_engine_info_t *lastp = &engine_info;

      gpgme_protocol_t proto_list[] = { GPGME_PROTOCOL_OpenPGP,

					GPGME_PROTOCOL_CMS,

					GPGME_PROTOCOL_GPGCONF,

					GPGME_PROTOCOL_ASSUAN,

					GPGME_PROTOCOL_G13,

					GPGME_PROTOCOL_UISERVER,

                                        GPGME_PROTOCOL_SPAWN    };

      unsigned int proto;

      err = 0;

      for (proto = 0; proto < DIM (proto_list); proto++)

	{

	  const char *ofile_name = engine_get_file_name (proto_list[proto]);

	  const char *ohome_dir  = engine_get_home_dir (proto_list[proto]);

          char *version = engine_get_version (proto_list[proto], NULL);

	  char *file_name;

	  char *home_dir;

	  if (!ofile_name)

	    continue;

	  file_name = strdup (ofile_name);

          if (!file_name)

            err = gpg_error_from_syserror ();

          if (ohome_dir)

            {

              home_dir = strdup (ohome_dir);

              if (!home_dir && !err)

                err = gpg_error_from_syserror ();

            }

          else

            home_dir = NULL;

	  *lastp = calloc (1, sizeof (*engine_info));

          if (!*lastp && !err)

            err = gpg_error_from_syserror ();

          /* Check against the optional minimal engine version.  */

          if (!err && version && engine_minimal_version

              && !_gpgme_compare_versions (version, engine_minimal_version))

            {

#if GPG_ERROR_VERSION_NUMBER < 0x011900 /* 1.25 */

              err = gpg_error (GPG_ERR_NO_ENGINE);

#else

              err = gpg_error (GPG_ERR_ENGINE_TOO_OLD);

#endif

            }

          /* Now set the dummy version for pseudo engines.  */

          if (!err && !version)

            {

              version = strdup ("1.0.0");

              if (!version)

                err = gpg_error_from_syserror ();

            }

	  if (err)

	    {

	      _gpgme_engine_info_release (engine_info);

	      engine_info = NULL;

	      if (file_name)

		free (file_name);

	      if (home_dir)

		free (home_dir);

	      if (version)

		free (version);

	      UNLOCK (engine_info_lock);

	      return err;

	    }

	  (*lastp)->protocol = proto_list[proto];

	  (*lastp)->file_name = file_name;

	  (*lastp)->home_dir = home_dir;

	  (*lastp)->version = version;

	  (*lastp)->req_version = engine_get_req_version (proto_list[proto]);

	  if (!(*lastp)->req_version)

            (*lastp)->req_version = "1.0.0"; /* Dummy for pseudo engines. */

	  (*lastp)->next = NULL;

	  lastp = &(*lastp)->next;

	}

    }

  *info = engine_info;

  UNLOCK (engine_info_lock);

  return 0;

}

/* Get a deep copy of the engine info and return it in INFO.  */

gpgme_error_t

_gpgme_engine_info_copy (gpgme_engine_info_t *r_info)

{

  gpgme_error_t err = 0;

  gpgme_engine_info_t info;

  gpgme_engine_info_t new_info;

  gpgme_engine_info_t *lastp;

  LOCK (engine_info_lock);

  info = engine_info;

  if (!info)

    {

      /* Make sure it is initialized.  */

      UNLOCK (engine_info_lock);

      err = gpgme_get_engine_info (&info;;

      if (err)

	return err;

      LOCK (engine_info_lock);

    }

  new_info = NULL;

  lastp = &new_info;

  while (info)

    {

      char *file_name;

      char *home_dir;

      char *version;

      assert (info->file_name);

      file_name = strdup (info->file_name);

      if (!file_name)

        err = gpg_error_from_syserror ();

      if (info->home_dir)

	{

	  home_dir = strdup (info->home_dir);

	  if (!home_dir && !err)

	    err = gpg_error_from_syserror ();

	}

      else

	home_dir = NULL;

      if (info->version)

	{

	  version = strdup (info->version);

	  if (!version && !err)

	    err = gpg_error_from_syserror ();

	}

      else

	version = NULL;

      *lastp = malloc (sizeof (*engine_info));

      if (!*lastp && !err)

        err = gpg_error_from_syserror ();

      if (err)

	{

	  _gpgme_engine_info_release (new_info);

	  if (file_name)

	    free (file_name);

	  if (home_dir)

	    free (home_dir);

	  if (version)

	    free (version);

	  UNLOCK (engine_info_lock);

	  return err;

	}

      (*lastp)->protocol = info->protocol;

      (*lastp)->file_name = file_name;

      (*lastp)->home_dir = home_dir;

      (*lastp)->version = version;

      (*lastp)->req_version = info->req_version;

      (*lastp)->next = NULL;

      lastp = &(*lastp)->next;

      info = info->next;

    }

  *r_info = new_info;

  UNLOCK (engine_info_lock);

  return 0;

}

/* Set the engine info for the info list INFO, protocol PROTO, to the

   file name FILE_NAME and the home directory HOME_DIR.  */

gpgme_error_t

_gpgme_set_engine_info (gpgme_engine_info_t info, gpgme_protocol_t proto,

			const char *file_name, const char *home_dir)

{

  char *new_file_name;

  char *new_home_dir;

  char *new_version;

  /* FIXME: Use some PROTO_MAX definition.  */

  if (proto > DIM (engine_ops))

    return gpg_error (GPG_ERR_INV_VALUE);

  while (info && info->protocol != proto)

    info = info->next;

  if (!info)

    return trace_gpg_error (GPG_ERR_INV_ENGINE);

  /* Prepare new members.  */

  if (file_name)

    new_file_name = strdup (file_name);

  else

    {

      const char *ofile_name = engine_get_file_name (proto);

      assert (ofile_name);

      new_file_name = strdup (ofile_name);

    }

  if (!new_file_name)

    return gpg_error_from_syserror ();

  if (home_dir)

    {

      new_home_dir = strdup (home_dir);

      if (!new_home_dir)

	{

	  free (new_file_name);

	  return gpg_error_from_syserror ();

	}

    }

  else

    {

      const char *ohome_dir = engine_get_home_dir (proto);

      if (ohome_dir)

        {

          new_home_dir = strdup (ohome_dir);

          if (!new_home_dir)

            {

              free (new_file_name);

              return gpg_error_from_syserror ();

            }

        }

      else

        new_home_dir = NULL;

    }

  new_version = engine_get_version (proto, new_file_name);

  if (!new_version)

    {

      new_version = strdup ("1.0.0"); /* Fake one for dummy entries.  */

      if (!new_version)

        {

          free (new_file_name);

          free (new_home_dir);

        }

    }

  /* Remove the old members.  */

  assert (info->file_name);

  free (info->file_name);

  if (info->home_dir)

    free (info->home_dir);

  if (info->version)

    free (info->version);

  /* Install the new members.  */

  info->file_name = new_file_name;

  info->home_dir = new_home_dir;

  info->version = new_version;

  return 0;

}

/* Set the default engine info for the protocol PROTO to the file name

   FILE_NAME and the home directory HOME_DIR.  */

gpgme_error_t

gpgme_set_engine_info (gpgme_protocol_t proto,

		       const char *file_name, const char *home_dir)

{

  gpgme_error_t err;

  gpgme_engine_info_t info;

  LOCK (engine_info_lock);

  info = engine_info;

  if (!info)

    {

      /* Make sure it is initialized.  */

      UNLOCK (engine_info_lock);

      err = gpgme_get_engine_info (&info;;

      if (err)

	return err;

      LOCK (engine_info_lock);

    }

  err = _gpgme_set_engine_info (info, proto, file_name, home_dir);

  UNLOCK (engine_info_lock);

  return err;

}

gpgme_error_t

_gpgme_engine_new (gpgme_engine_info_t info, engine_t *r_engine)

{

  engine_t engine;

  if (!info->file_name || !info->version)

    return trace_gpg_error (GPG_ERR_INV_ENGINE);

  engine = calloc (1, sizeof *engine);

  if (!engine)

    return gpg_error_from_syserror ();

  engine->ops = engine_ops[info->protocol];

  if (engine->ops->new)

    {

      gpgme_error_t err;

      err = (*engine->ops->new) (&engine->engine,

				 info->file_name, info->home_dir,

                                 info->version);

      if (err)

	{

	  free (engine);

	  return err;

	}

    }

  else

    engine->engine = NULL;

  *r_engine = engine;

  return 0;

}

gpgme_error_t

_gpgme_engine_reset (engine_t engine)

{

  if (!engine)

    return gpg_error (GPG_ERR_INV_VALUE);

  if (!engine->ops->reset)

    return gpg_error (GPG_ERR_NOT_IMPLEMENTED);

  return (*engine->ops->reset) (engine->engine);

}

void

_gpgme_engine_release (engine_t engine)

{

  if (!engine)

    return;

  if (engine->ops->release)

    (*engine->ops->release) (engine->engine);

  free (engine);

}

/* Set a status callback which is used to monitor the status values

 * before they are passed to a handler set with

 * _gpgme_engine_set_status_handler.  */

void

_gpgme_engine_set_status_cb (engine_t engine,

                             gpgme_status_cb_t cb, void *cb_value)

{

  if (!engine)

    return;

  if (engine->ops->set_status_cb)

    (*engine->ops->set_status_cb) (engine->engine, cb, cb_value);

}

void

_gpgme_engine_set_status_handler (engine_t engine,

				  engine_status_handler_t fnc, void *fnc_value)

{

  if (!engine)

    return;

  if (engine->ops->set_status_handler)

    (*engine->ops->set_status_handler) (engine->engine, fnc, fnc_value);

}

gpgme_error_t

_gpgme_engine_set_command_handler (engine_t engine,

				   engine_command_handler_t fnc,

				   void *fnc_value,

				   gpgme_data_t linked_data)

{

  if (!engine)

    return gpg_error (GPG_ERR_INV_VALUE);

  if (!engine->ops->set_command_handler)

    return gpg_error (GPG_ERR_NOT_IMPLEMENTED);

  return (*engine->ops->set_command_handler) (engine->engine,

					      fnc, fnc_value, linked_data);

}

gpgme_error_t

_gpgme_engine_set_colon_line_handler (engine_t engine,

				      engine_colon_line_handler_t fnc,

				      void *fnc_value)

{

  if (!engine)

    return gpg_error (GPG_ERR_INV_VALUE);

  if (!engine->ops->set_colon_line_handler)

    return gpg_error (GPG_ERR_NOT_IMPLEMENTED);

  return (*engine->ops->set_colon_line_handler) (engine->engine,

						 fnc, fnc_value);

}

gpgme_error_t

_gpgme_engine_set_locale (engine_t engine, int category,

			  const char *value)

{

  if (!engine)

    return gpg_error (GPG_ERR_INV_VALUE);

  if (!engine->ops->set_locale)

    return gpg_error (GPG_ERR_NOT_IMPLEMENTED);

  return (*engine->ops->set_locale) (engine->engine, category, value);

}

gpgme_error_t

_gpgme_engine_set_protocol (engine_t engine, gpgme_protocol_t protocol)

{

  if (!engine)

    return gpg_error (GPG_ERR_INV_VALUE);

  if (!engine->ops->set_protocol)

    return gpg_error (GPG_ERR_NOT_IMPLEMENTED);

  return (*engine->ops->set_protocol) (engine->engine, protocol);

}

gpgme_error_t

_gpgme_engine_op_decrypt (engine_t engine,

                          gpgme_decrypt_flags_t flags,

                          gpgme_data_t ciph,

			  gpgme_data_t plain, int export_session_key,

                          const char *override_session_key,

                          int auto_key_retrieve)

{

  if (!engine)

    return gpg_error (GPG_ERR_INV_VALUE);

  if (!engine->ops->decrypt)

    return gpg_error (GPG_ERR_NOT_IMPLEMENTED);

  return (*engine->ops->decrypt) (engine->engine, flags, ciph, plain,

                                  export_session_key, override_session_key,

                                  auto_key_retrieve);

}

gpgme_error_t

_gpgme_engine_op_delete (engine_t engine, gpgme_key_t key,

			 unsigned int flags)

{

  if (!engine)

    return gpg_error (GPG_ERR_INV_VALUE);

  if (!engine->ops->delete)

    return gpg_error (GPG_ERR_NOT_IMPLEMENTED);

  return (*engine->ops->delete) (engine->engine, key, flags);

}

gpgme_error_t

_gpgme_engine_op_edit (engine_t engine, int type, gpgme_key_t key,

		       gpgme_data_t out, gpgme_ctx_t ctx /* FIXME */)

{

  if (!engine)

    return gpg_error (GPG_ERR_INV_VALUE);

  if (!engine->ops->edit)

    return gpg_error (GPG_ERR_NOT_IMPLEMENTED);

  return (*engine->ops->edit) (engine->engine, type, key, out, ctx);

}

gpgme_error_t

_gpgme_engine_op_encrypt (engine_t engine, gpgme_key_t recp[],

			  gpgme_encrypt_flags_t flags,

			  gpgme_data_t plain, gpgme_data_t ciph, int use_armor)

{

  if (!engine)

    return gpg_error (GPG_ERR_INV_VALUE);

  if (!engine->ops->encrypt)

    return gpg_error (GPG_ERR_NOT_IMPLEMENTED);

  return (*engine->ops->encrypt) (engine->engine, recp, flags, plain, ciph,

				  use_armor);

}

gpgme_error_t

_gpgme_engine_op_encrypt_sign (engine_t engine, gpgme_key_t recp[],

			       gpgme_encrypt_flags_t flags,

			       gpgme_data_t plain, gpgme_data_t ciph,

			       int use_armor, gpgme_ctx_t ctx /* FIXME */)

{

  if (!engine)

    return gpg_error (GPG_ERR_INV_VALUE);

  if (!engine->ops->encrypt_sign)

    return gpg_error (GPG_ERR_NOT_IMPLEMENTED);

  return (*engine->ops->encrypt_sign) (engine->engine, recp, flags,

				       plain, ciph, use_armor, ctx);

}

gpgme_error_t

_gpgme_engine_op_export (engine_t engine, const char *pattern,

			 gpgme_export_mode_t mode, gpgme_data_t keydata,

			 int use_armor)

{

  if (!engine)

    return gpg_error (GPG_ERR_INV_VALUE);

  if (!engine->ops->export)

    return gpg_error (GPG_ERR_NOT_IMPLEMENTED);

  return (*engine->ops->export) (engine->engine, pattern, mode,

				 keydata, use_armor);

}

gpgme_error_t

_gpgme_engine_op_export_ext (engine_t engine, const char *pattern[],

			     unsigned int reserved, gpgme_data_t keydata,

			     int use_armor)

{

  if (!engine)

    return gpg_error (GPG_ERR_INV_VALUE);

  if (!engine->ops->export_ext)

    return gpg_error (GPG_ERR_NOT_IMPLEMENTED);

  return (*engine->ops->export_ext) (engine->engine, pattern, reserved,

				     keydata, use_armor);

}

gpgme_error_t

_gpgme_engine_op_genkey (engine_t engine,

                         const char *userid, const char *algo,

                         unsigned long reserved, unsigned long expires,

                         gpgme_key_t key, unsigned int flags,

                         gpgme_data_t help_data,

			 unsigned int extraflags,

                         gpgme_data_t pubkey, gpgme_data_t seckey)

{

  if (!engine)

    return gpg_error (GPG_ERR_INV_VALUE);

  if (!engine->ops->genkey)

    return gpg_error (GPG_ERR_NOT_IMPLEMENTED);

  return (*engine->ops->genkey) (engine->engine,

                                 userid, algo, reserved, expires, key, flags,

                                 help_data, extraflags,

				 pubkey, seckey);

}

gpgme_error_t

_gpgme_engine_op_keysign (engine_t engine, gpgme_key_t key, const char *userid,

                          unsigned long expires, unsigned int flags,

                          gpgme_ctx_t ctx)

{

  if (!engine)

    return gpg_error (GPG_ERR_INV_VALUE);

  if (!engine->ops->keysign)

    return gpg_error (GPG_ERR_NOT_IMPLEMENTED);

  return (*engine->ops->keysign) (engine->engine,

                                  key, userid, expires, flags, ctx);

}

gpgme_error_t

_gpgme_engine_op_tofu_policy (engine_t engine,

                              gpgme_key_t key,  gpgme_tofu_policy_t policy)

{

  if (!engine)

    return gpg_error (GPG_ERR_INV_VALUE);

  if (!engine->ops->tofu_policy)

    return gpg_error (GPG_ERR_NOT_IMPLEMENTED);

  return (*engine->ops->tofu_policy) (engine->engine, key, policy);

}

gpgme_error_t

_gpgme_engine_op_import (engine_t engine, gpgme_data_t keydata,

                         gpgme_key_t *keyarray)

{

  if (!engine)

    return gpg_error (GPG_ERR_INV_VALUE);

  if (!engine->ops->import)

    return gpg_error (GPG_ERR_NOT_IMPLEMENTED);

  return (*engine->ops->import) (engine->engine, keydata, keyarray);

}

gpgme_error_t

_gpgme_engine_op_keylist (engine_t engine, const char *pattern,

			  int secret_only, gpgme_keylist_mode_t mode,

			  int engine_flags)

{

  if (!engine)

    return gpg_error (GPG_ERR_INV_VALUE);

  if (!engine->ops->keylist)

    return gpg_error (GPG_ERR_NOT_IMPLEMENTED);

  return (*engine->ops->keylist) (engine->engine, pattern, secret_only, mode,

                                  engine_flags);

}

gpgme_error_t

_gpgme_engine_op_keylist_ext (engine_t engine, const char *pattern[],

			      int secret_only, int reserved,

			      gpgme_keylist_mode_t mode, int engine_flags)

{

  if (!engine)

    return gpg_error (GPG_ERR_INV_VALUE);

  if (!engine->ops->keylist_ext)

    return gpg_error (GPG_ERR_NOT_IMPLEMENTED);

  return (*engine->ops->keylist_ext) (engine->engine, pattern, secret_only,

				      reserved, mode, engine_flags);

}

gpgme_error_t

_gpgme_engine_op_keylist_data (engine_t engine, gpgme_data_t data)

{

  if (!engine)

    return gpg_error (GPG_ERR_INV_VALUE);

  if (!engine->ops->keylist_data)

    return gpg_error (GPG_ERR_NOT_IMPLEMENTED);

  return (*engine->ops->keylist_data) (engine->engine, data);

}

gpgme_error_t

_gpgme_engine_op_sign (engine_t engine, gpgme_data_t in, gpgme_data_t out,

		       gpgme_sig_mode_t mode, int use_armor,