qa_auth_interface.c

/*  Copyright (c) 2010, 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 as
    published by the Free Software Foundation; version 2 of the
    License.
    
    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 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 <my_global.h>
#include <mysql/plugin_auth.h>
#include <mysql/client_plugin.h>
#include <string.h>
#include <stdio.h>
#include <stdlib.h>

#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;

/* Check the contens of components of info */
  if (strcmp(info->user_name, "qa_test_1_user")== 0)
  {
    if (info->user_name_length != 14)
       err= CR_ERROR;
    if (strcmp(info->auth_string, "qa_test_1_dest"))
       err= CR_ERROR;
    if (info->auth_string_length != 14)
       err= CR_ERROR;
/*
  To be set by the plugin
    if (strcmp(info->authenticated_as, "qa_test_1_user"))
         err= CR_ERROR;
    if (strcmp(info->external_user, ""))
         err= CR_ERROR;
*/
    if (info->password_used != PASSWORD_USED_YES)
       err= CR_ERROR;
    if (strcmp(info->host_or_ip, "localhost"))
       err= CR_ERROR;
    if (info->host_or_ip_length != 9)
       err= CR_ERROR;
  }
/* Assign values to the components of info even if not intended and watch the effect */
  else if (strcmp(info->user_name, "qa_test_2_user")== 0)
  {
    /* Overwriting not intended, but with effect on USER() */
     strcpy(info->user_name, "user_name");
     info->user_name_length= 9;
    /* Overwriting not intended, effect not visible */
     strcpy((char *)info->auth_string, "auth_string");
     info->auth_string_length= 11;
    /* Assign with account for authorization, effect on CURRENT_USER() */
     strcpy(info->authenticated_as, "authenticated_as");
    /* Assign with an external account, effect on @@local.EXTERNAL_USER */
     strcpy(info->external_user, "externaluser");
    /*
      Overwriting will cause a core dump
      strcpy(info->host_or_ip, "host_or_ip");
      info->host_or_ip_length= 10;
    */
  }
/* Invalid, means too high values for length */
  else if (strcmp(info->user_name, "qa_test_3_user")== 0)
  {
/* Original value is 14. Test runs also with higher value. Changes have no effect.*/
     info->user_name_length= 28;
     strcpy((char *)info->auth_string, "qa_test_3_dest");
/* Original value is 14. Test runs also with higher value. Changes have no effect.*/
     info->auth_string_length= 28;
     strcpy(info->authenticated_as, info->auth_string);
     strcpy(info->external_user, info->auth_string);
  }
/* Invalid, means too low values for length */
  else if (strcmp(info->user_name, "qa_test_4_user")== 0)
  {
/* Original value is 14. Test runs also with lower value. Changes have no effect.*/
     info->user_name_length= 8;
     strcpy((char *)info->auth_string, "qa_test_4_dest");
/* Original value is 14. Test runs also with lower value. Changes have no effect.*/
     info->auth_string_length= 8;
     strcpy(info->authenticated_as, info->auth_string);
     strcpy(info->external_user, info->auth_string);
  }
/* Overwrite with empty values */
  else if (strcmp(info->user_name, "qa_test_5_user")== 0)  
  {
/* This assignment has no effect.*/
     strcpy(info->user_name, "");
     info->user_name_length= 0;
/* This assignment has no effect.*/
     strcpy((char *)info->auth_string, "");
     info->auth_string_length= 0;
/* This assignment caused an error or an "empty" user */
     strcpy(info->authenticated_as, "");
/* This assignment has no effect.*/
     strcpy(info->external_user, "");
    /*
      Overwriting will cause a core dump
      strcpy(info->host_or_ip, "");
      info->host_or_ip_length= 0;
    */
  }
/* Set to 'root' */
  else if (strcmp(info->user_name, "qa_test_6_user")== 0)
  {
     strcpy(info->authenticated_as, "root");
  }
  else
  {
     err= CR_ERROR;
  }
  return err;
}

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
};

mysql_declare_plugin(test_plugin)
{
  MYSQL_AUTHENTICATION_PLUGIN,
  &qa_auth_test_handler,
  "qa_auth_interface",
  "Horst Hunger",
  "plugin API test plugin",
  PLUGIN_LICENSE_GPL,
  NULL,
  NULL,
  0x0100,
  NULL,
  NULL,
  NULL,
  0,
}
mysql_declare_plugin_end;

/********************* CLIENT SIDE ***************************************/
/*
  client plugin used for testing the plugin API
*/
#include <mysql.h>

static int test_plugin_client(MYSQL_PLUGIN_VIO *vio, MYSQL *mysql)
{
  unsigned char *pkt, cmd= 0;
  int pkt_len, res;
  char *reply;

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

    if (pkt == 0)
    {
      /*
        in mysql_change_user() the client sends the first packet, so
        the first vio->read_packet() does nothing (pkt == 0).

        We send the "password", assuming the client knows what its doing.
        (in other words, the dialog plugin should be only set as a default
        authentication plugin on the client if the first question
        asks for a password - which will be sent in cleat text, by the way)
      */
      reply= mysql->passwd;
    }
    else
    {
      cmd= *pkt++;

      /* is it MySQL protocol (0=OK or 254=need old password) packet ? */
      if (cmd == 0 || cmd == 254)
        return CR_OK_HANDSHAKE_COMPLETE; /* yes. we're done */

      /*
        asking for a password with an empty prompt means mysql->password
        otherwise return an error
      */
      if ((cmd == LAST_PASSWORD[0] || cmd == PASSWORD_QUESTION[0]) && *pkt == 0)
        reply= mysql->passwd;
      else
        return CR_ERROR;
    }
    if (!reply)
      return CR_ERROR;
    /* send the reply to the server */
    res= vio->write_packet(vio, (const unsigned char *) reply, 
                           strlen(reply) + 1);

    if (res)
      return CR_ERROR;

    /* repeat unless it was the last question */
  } while (cmd != LAST_QUESTION[0] && cmd != PASSWORD_QUESTION[0]);

  /* the job of reading the ok/error packet is left to the server */
  return CR_OK;
}


mysql_declare_client_plugin(AUTHENTICATION)
  "qa_auth_interface",
  "Horst Hunger",
  "Dialog Client Authentication Plugin",
  {0,1,0},
  "GPL",
  NULL,
  NULL,
  NULL,
  NULL,
  test_plugin_client
mysql_end_client_plugin;