/*  Copyright (c) 2010, 2017, Oracle and/or its affiliates. All rights reserved.

    This program is free software; you can redistribute it and/or modify
    it under the terms of the GNU General Public License, version 2.0,
    as published by the Free Software Foundation.

    This program is also distributed with certain software (including
    but not limited to OpenSSL) that is licensed under separate terms,
    as designated in a particular file or component or in included license
    documentation.  The authors of MySQL hereby grant you an additional
    permission to link the program and your derivative works with the
    separately licensed software that they have included with MySQL.

    This program 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, version 2.0, for more details.

    You should have received a copy of the GNU General Public License
    along with this program; if not, write to the Free Software
    Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301  USA */

#include <mysql/client_plugin.h>
#include <mysql/plugin_auth.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>

#include "my_compiler.h"

/**
  first byte of the question string is the question "type".
  It can be a "ordinary" or a "password" question.
  The last bit set marks a last question in the authentication exchange.
*/
#define ORDINARY_QUESTION "\2"
#define LAST_QUESTION "\3"
#define LAST_PASSWORD "\4"
#define PASSWORD_QUESTION "\5"

/********************* SERVER SIDE ****************************************/

static int qa_auth_interface(MYSQL_PLUGIN_VIO *vio,
                             MYSQL_SERVER_AUTH_INFO *info) {
  unsigned char *pkt;
  int pkt_len, err = CR_OK;

  /* send a password question */
  if (vio->write_packet(vio, (const unsigned char *)PASSWORD_QUESTION, 1))
    return CR_ERROR;

  /* read the answer */
  if ((pkt_len = vio->read_packet(vio, &pkt)) < 0) return CR_ERROR;

  info->password_used = PASSWORD_USED_YES;

  /* fail if the password is wrong */
  if (strcmp((const char *)pkt, info->auth_string)) return CR_ERROR;

  /* Test of default_auth */
  if (strcmp(info->user_name, "qa_test_11_user") == 0) {
    strcpy(info->authenticated_as, "qa_test_11_dest");
  } else
    err = CR_ERROR;
  return err;
}

static int generate_auth_string_hash(char *outbuf, unsigned int *buflen,
                                     const char *inbuf, unsigned int inbuflen) {
  /*
    if buffer specified by server is smaller than the buffer given
    by plugin then return error
  */
  if (*buflen < inbuflen) return 1;
  strncpy(outbuf, inbuf, inbuflen);
  *buflen = strlen(inbuf);
  return 0;
}

static int validate_auth_string_hash(char *const inbuf MY_ATTRIBUTE((unused)),
                                     unsigned int buflen
                                         MY_ATTRIBUTE((unused))) {
  return 0;
}

static int set_salt(const char *password MY_ATTRIBUTE((unused)),
                    unsigned int password_len MY_ATTRIBUTE((unused)),
                    unsigned char *salt MY_ATTRIBUTE((unused)),
                    unsigned char *salt_len) {
  *salt_len = 0;
  return 0;
}

static struct st_mysql_auth qa_auth_test_handler = {
    MYSQL_AUTHENTICATION_INTERFACE_VERSION,
    "qa_auth_interface", /* requires test_plugin client's plugin */
    qa_auth_interface,
    generate_auth_string_hash,
    validate_auth_string_hash,
    set_salt,
    AUTH_FLAG_PRIVILEGED_USER_FOR_PASSWORD_CHANGE,
    NULL};

mysql_declare_plugin(test_plugin){
    MYSQL_AUTHENTICATION_PLUGIN,
    &qa_auth_test_handler,
    "qa_auth_server",
    "Horst Hunger",
    "plugin API test plugin",
    PLUGIN_LICENSE_GPL,
    NULL, /* Init */
    NULL, /* Check uninstall */
    NULL, /* Deinit */
    0x0101,
    NULL,
    NULL,
    NULL,
    0,
} mysql_declare_plugin_end;