/* -*- mode: C; c-file-style: "gnu"; indent-tabs-mode: nil; -*- */

/*

 * Copyright © 2011 – 2017 Red Hat, Inc.

 *

 * This library 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 of the License, or (at your option) any later version.

 *

 * This library 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 library; if not, see <http://www.gnu.org/licenses/>.

 */

#include "config.h"

#include <string.h>

#include <gio/gio.h>

#include <glib/gi18n-lib.h>

#include <stdlib.h>

#include "goaimapauthlogin.h"

#include "goautils.h"

/*

 * SECTION:goaimapauthlogin

 * @title: GoaImapAuthLogin

 * @short_description: LOGIN authentication method for IMAP

 *

 * #GoaImapAuthLogin implements the standard 

 * url="http://tools.ietf.org/html/rfc3501#section-6.2.3">LOGIN</ulink>

 * authentication method (e.g. using usernames / passwords) for IMAP.

 */

/*

 * GoaImapAuthLogin:

 *

 * The #GoaImapAuthLogin structure contains only private data

 * and should only be accessed using the provided API.

 */

struct _GoaImapAuthLogin

{

  GoaMailAuth parent_instance;

  gboolean greeting_absent;

  gchar *username;

  gchar *password;

};

enum

{

  PROP_0,

  PROP_USERNAME,

  PROP_PASSWORD

};

static gboolean goa_imap_auth_login_is_needed (GoaMailAuth        *auth);

static gboolean goa_imap_auth_login_run_sync (GoaMailAuth         *auth,

                                              GCancellable        *cancellable,

                                              GError             **error);

static gboolean goa_imap_auth_login_starttls_sync (GoaMailAuth    *auth,

                                                   GCancellable   *cancellable,

                                                   GError        **error);

G_DEFINE_TYPE (GoaImapAuthLogin, goa_imap_auth_login, GOA_TYPE_MAIL_AUTH);

/* ---------------------------------------------------------------------------------------------------- */

static const gchar *IMAP_TAG = "A001";

static gboolean

imap_auth_login_check_BYE (const gchar *response, GError **error)

{

  if (g_str_has_prefix (response, "* BYE"))

    {

      g_set_error (error,

                   GOA_ERROR,

                   GOA_ERROR_FAILED, /* TODO: more specific */

                   _("Service not available"));

      return TRUE;

    }

  return FALSE;

}

static gboolean

imap_auth_login_check_NO (const gchar *response, GError **error)

{

  gboolean ret = FALSE;

  gchar *str = NULL;

  str = g_strdup_printf ("%s NO", IMAP_TAG);

  if (g_str_has_prefix (response, str))

    {

      g_set_error (error,

                   GOA_ERROR,

                   GOA_ERROR_FAILED, /* TODO: more specific */

                   _("Authentication failed"));

      ret = TRUE;

    }

  g_free (str);

  return ret;

}

static gboolean

imap_auth_login_check_not_CAPABILITY (const gchar *response)

{

  if (!g_str_has_prefix (response, "* CAPABILITY"))

    return TRUE;

  return FALSE;

}

static gboolean

imap_auth_login_check_not_LOGIN (const gchar *response, GError **error)

{

  if (strstr (response, "AUTH=PLAIN") == NULL)

    {

      g_set_error (error,

                   GOA_ERROR,

                   GOA_ERROR_NOT_SUPPORTED,

                   _("Server does not support PLAIN"));

      return TRUE;

    }

  return FALSE;

}

static gboolean

imap_auth_login_check_not_OK (const gchar *response, gboolean tagged, GError **error)

{

  gboolean ret = FALSE;

  if (tagged)

    {

      gchar *str;

      str = g_strdup_printf ("%s OK", IMAP_TAG);

      if (!g_str_has_prefix (response, str))

        {

          g_set_error (error,

                       GOA_ERROR,

                       GOA_ERROR_FAILED, /* TODO: more specific */

                       "Unexpected response `%s' while doing LOGIN authentication",

                       response);

          ret = TRUE;

        }

      g_free (str);

    }

  else

    {

      if (!g_str_has_prefix (response, "* OK"))

        {

          g_set_error (error,

                       GOA_ERROR,

                       GOA_ERROR_FAILED, /* TODO: more specific */

                       "Unexpected response `%s' while doing LOGIN authentication",

                       response);

          ret = TRUE;

        }

    }

  return ret;

}

static gboolean

imap_auth_login_check_not_STARTTLS (const gchar *response, GError **error)

{

  if (strstr (response, "STARTTLS") == NULL)

    {

      g_set_error (error,

                   GOA_ERROR,

                   GOA_ERROR_NOT_SUPPORTED,

                   _("Server does not support STARTTLS"));

      return TRUE;

    }

  return FALSE;

}

/* ---------------------------------------------------------------------------------------------------- */

static gchar *

imap_auth_escape_backslash (const gchar *str)

{

  GString *ret;

  gsize i;

  gsize len;

  ret = g_string_new ("");

  len = strlen (str);

  for (i = 0; i < len; i++)

    {

      if (str[i] == '\\')

        g_string_append_c (ret, '\\');

      g_string_append_c (ret, str[i]);

    }

  return g_string_free (ret, FALSE);

}

/* ---------------------------------------------------------------------------------------------------- */

static void

goa_imap_auth_login_finalize (GObject *object)

{

  GoaImapAuthLogin *self = GOA_IMAP_AUTH_LOGIN (object);

  g_free (self->username);

  g_free (self->password);

  G_OBJECT_CLASS (goa_imap_auth_login_parent_class)->finalize (object);

}

static void

goa_imap_auth_login_get_property (GObject      *object,

                                  guint         prop_id,

                                  GValue       *value,

                                  GParamSpec   *pspec)

{

  GoaImapAuthLogin *self = GOA_IMAP_AUTH_LOGIN (object);

  switch (prop_id)

    {

    case PROP_USERNAME:

      g_value_set_string (value, self->username);

      break;

    case PROP_PASSWORD:

      g_value_set_string (value, self->password);

      break;

    default:

      G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);

      break;

    }

}

static void

goa_imap_auth_login_set_property (GObject      *object,

                                  guint         prop_id,

                                  const GValue *value,

                                  GParamSpec   *pspec)

{

  GoaImapAuthLogin *self = GOA_IMAP_AUTH_LOGIN (object);

  switch (prop_id)

    {

    case PROP_USERNAME:

      self->username = g_value_dup_string (value);

      break;

    case PROP_PASSWORD:

      self->password = g_value_dup_string (value);

      break;

    default:

      G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);

      break;

    }

}

/* ---------------------------------------------------------------------------------------------------- */

static void

goa_imap_auth_login_init (GoaImapAuthLogin *self)

{

}

static void

goa_imap_auth_login_class_init (GoaImapAuthLoginClass *klass)

{

  GObjectClass *gobject_class;

  GoaMailAuthClass *auth_class;

  gobject_class = G_OBJECT_CLASS (klass);

  gobject_class->finalize     = goa_imap_auth_login_finalize;

  gobject_class->get_property = goa_imap_auth_login_get_property;

  gobject_class->set_property = goa_imap_auth_login_set_property;

  auth_class = GOA_MAIL_AUTH_CLASS (klass);

  auth_class->is_needed = goa_imap_auth_login_is_needed;

  auth_class->run_sync = goa_imap_auth_login_run_sync;

  auth_class->starttls_sync = goa_imap_auth_login_starttls_sync;

  /**

   * GoaImapAuthLogin:user-name:

   *

   * The user name.

   */

  g_object_class_install_property (gobject_class,

                                   PROP_USERNAME,

                                   g_param_spec_string ("user-name",

                                                        "user-name",

                                                        "user-name",

                                                        NULL,

                                                        G_PARAM_READABLE |

                                                        G_PARAM_WRITABLE |

                                                        G_PARAM_CONSTRUCT_ONLY |

                                                        G_PARAM_STATIC_STRINGS));

  /**

   * GoaImapAuthLogin:password:

   *

   * The password.

   */

  g_object_class_install_property (gobject_class,

                                   PROP_PASSWORD,

                                   g_param_spec_string ("password",

                                                        "password",

                                                        "password",

                                                        NULL,

                                                        G_PARAM_READABLE |

                                                        G_PARAM_WRITABLE |

                                                        G_PARAM_CONSTRUCT_ONLY |

                                                        G_PARAM_STATIC_STRINGS));

}

/* ---------------------------------------------------------------------------------------------------- */

/**

 * goa_imap_auth_login_new:

 * @username: The user name to use.

 * @password: The password to use.

 *

 * Creates a new #GoaMailAuth to be used for username/password

 * authentication using LOGIN over IMAP.

 *

 * Returns: (type GoaImapAuthLogin): A #GoaImapAuthLogin. Free with

 * g_object_unref().

 */

GoaMailAuth *

goa_imap_auth_login_new (const gchar       *username,

                         const gchar       *password)

{

  g_return_val_if_fail (username != NULL, NULL);

  g_return_val_if_fail (password != NULL && password[0] != '\0', NULL);

  return GOA_MAIL_AUTH (g_object_new (GOA_TYPE_IMAP_AUTH_LOGIN,

                                      "user-name", username,

                                      "password", password,

                                      NULL));

}

/* ---------------------------------------------------------------------------------------------------- */

static gboolean

goa_imap_auth_login_is_needed (GoaMailAuth *auth)

{

  /* TODO: support authentication-less IMAP servers */

  return TRUE;

}

/* ---------------------------------------------------------------------------------------------------- */

static gboolean

goa_imap_auth_login_run_sync (GoaMailAuth         *auth,

                              GCancellable        *cancellable,

                              GError             **error)

{

  GoaImapAuthLogin *self = GOA_IMAP_AUTH_LOGIN (auth);

  GDataInputStream *input;

  GDataOutputStream *output;

  gchar *request = NULL;

  gchar *response = NULL;

  gboolean ret = FALSE;

  gchar *password = NULL;

  password = imap_auth_escape_backslash (self->password);

  input = goa_mail_auth_get_input (auth);

  output = goa_mail_auth_get_output (auth);

  /* Check the greeting, if there is one */

  if (!self->greeting_absent)

    {

      response = goa_utils_data_input_stream_read_line (input, NULL, cancellable, error);

      if (response == NULL)

        goto out;

      g_debug ("< %s", response);

      if (imap_auth_login_check_BYE (response, error))

        goto out;

      if (imap_auth_login_check_not_OK (response, FALSE, error))

        goto out;

      g_clear_pointer (&response, g_free);

    }

  /* Send CAPABILITY */

  request = g_strdup_printf ("%s CAPABILITY\r\n", IMAP_TAG);

  g_debug ("> %s", request);

  if (!g_data_output_stream_put_string (output, request, cancellable, error))

    goto out;

  g_clear_pointer (&request, g_free);

  /* Check if LOGIN is supported or not */

  response = goa_utils_data_input_stream_read_line (input, NULL, cancellable, error);

  if (response == NULL)

    goto out;

  g_debug ("< %s", response);

  if (imap_auth_login_check_not_LOGIN (response, error))

    goto out;

  g_clear_pointer (&response, g_free);

  response = goa_utils_data_input_stream_read_line (input, NULL, cancellable, error);

  if (response == NULL)

    goto out;

  g_debug ("< %s", response);

  if (imap_auth_login_check_not_OK (response, TRUE, error))

    goto out;

  g_clear_pointer (&response, g_free);

  /* Send LOGIN */

  request = g_strdup_printf ("%s LOGIN \"%s\" \"%s\"\r\n", IMAP_TAG, self->username, password);

  g_debug ("> %s LOGIN \"********************\" \"********************\"", IMAP_TAG);

  if (!g_data_output_stream_put_string (output, request, cancellable, error))

    goto out;

  g_clear_pointer (&request, g_free);

  /* Skip post-login CAPABILITY, if any */

  response = goa_utils_data_input_stream_read_line (input, NULL, cancellable, error);

  if (response == NULL)

    goto out;

  g_debug ("< %s", response);

  if (imap_auth_login_check_not_CAPABILITY (response))

    goto check_login_response;

  g_clear_pointer (&response, g_free);

  response = goa_utils_data_input_stream_read_line (input, NULL, cancellable, error);

  if (response == NULL)

    goto out;

  g_debug ("< %s", response);

 check_login_response:

  if (imap_auth_login_check_NO (response, error))

    goto out;

  if (imap_auth_login_check_not_OK (response, TRUE, error))

    goto out;

  g_clear_pointer (&response, g_free);

  ret = TRUE;

 out:

  g_free (response);

  g_free (request);

  g_free (password);

  return ret;

}

/* ---------------------------------------------------------------------------------------------------- */

static gboolean

goa_imap_auth_login_starttls_sync (GoaMailAuth         *auth,

                                   GCancellable        *cancellable,

                                   GError             **error)

{

  GoaImapAuthLogin *self = GOA_IMAP_AUTH_LOGIN (auth);

  GDataInputStream *input;

  GDataOutputStream *output;

  gchar *request = NULL;

  gchar *response = NULL;

  gboolean ret = FALSE;

  input = goa_mail_auth_get_input (auth);

  output = goa_mail_auth_get_output (auth);

  /* Check the greeting */

  response = goa_utils_data_input_stream_read_line (input, NULL, cancellable, error);

  if (response == NULL)

    goto out;

  g_debug ("< %s", response);

  if (imap_auth_login_check_BYE (response, error))

    goto out;

  if (imap_auth_login_check_not_OK (response, FALSE, error))

    goto out;

  g_clear_pointer (&response, g_free);

  /* Send CAPABILITY */

  request = g_strdup_printf ("%s CAPABILITY\r\n", IMAP_TAG);

  g_debug ("> %s", request);

  if (!g_data_output_stream_put_string (output, request, cancellable, error))

    goto out;

  g_clear_pointer (&request, g_free);

  /* Check if STARTTLS is supported or not */

  response = goa_utils_data_input_stream_read_line (input, NULL, cancellable, error);

  if (response == NULL)

    goto out;

  g_debug ("< %s", response);

  if (imap_auth_login_check_not_STARTTLS (response, error))

    goto out;

  g_clear_pointer (&response, g_free);

  response = goa_utils_data_input_stream_read_line (input, NULL, cancellable, error);

  if (response == NULL)

    goto out;

  g_debug ("< %s", response);

  if (imap_auth_login_check_not_OK (response, TRUE, error))

    goto out;

  g_clear_pointer (&response, g_free);

  /* Send STARTTLS */

  request = g_strdup_printf ("%s STARTTLS\r\n", IMAP_TAG);

  g_debug ("> %s", request);

  if (!g_data_output_stream_put_string (output, request, cancellable, error))

    goto out;

  g_clear_pointer (&request, g_free);

  response = goa_utils_data_input_stream_read_line (input, NULL, cancellable, error);

  if (response == NULL)

    goto out;

  g_debug ("< %s", response);

  if (imap_auth_login_check_not_OK (response, TRUE, error))

    goto out;

  g_clear_pointer (&response, g_free);

  /* There won't be a greeting after this */

  self->greeting_absent = TRUE;

  ret = TRUE;

 out:

  g_free (response);

  g_free (request);

  return ret;

}