<?php
/** DomFramework
    @package domframework
    @author Dominique Fournier <dominique@fournier38.fr> */

require_once ("domframework/dblayer.php");

/** User authentication against SQL database */
class authsql extends auth
{

  public $dsn = null;
  public $username = null;
  public $password = null;
  public $driver_options = null;
  /** The table name to use */
  public $table = null;
  /** The tableprefix text to prepend to table name (Should finish by _)
      Just allow chars ! */
  public $tableprefix = "";
  /** The password field name */
  public $fieldPassword = "password";
  /** The identifier field name (maybe email) */
  public $fieldIdentifier = "email";
  /** The informations fields (in an array) */
  public $fieldsInfo = array ();

  /** The DBLayer pointer */
  private $db = null;
  /** The details of the authenticated user */
  private $details = null;

  /** Establish a connection to a SQL server */
  public function connect ()
  {
    if (! function_exists ("openssl_random_pseudo_bytes"))
      throw new Exception ("No PHP support for openssl_random_pseudo_bytes",
                           500);
    $this->db = new dblayer ($this->dsn, $this->username, $this->password,
                             $this->driver_options);
    if ($this->table === null)
      throw new Exception ("No SQL table defined", 500);
    if ($this->fieldIdentifier === null)
      throw new Exception ("No fieldIdentifier defined", 500);
    if ($this->fieldPassword === null)
      throw new Exception ("No fieldPassword defined", 500);
    $fields = array_merge (array ($this->fieldIdentifier, $this->fieldPassword),
                           $this->fieldsInfo);
    $fields = array_flip ($fields);
    foreach ($fields as $key=>$val)
      $fields[$key] = array ("varchar","255");
    $this->db->table = $this->table;
    $this->db->fields = $fields;
    $this->db->primary = $this->fieldIdentifier;
  }

  /** Try to authenticate the email/password of the user
      @param string $email Email to authenticate
      @param string $password Password to authenticate */
  public function authentication ($email, $password)
  {
    if ($this->db === null)
      throw new Exception ("The SQL database is not connected", 500);
    $data = $this->db->read (array (array ($this->fieldIdentifier, $email)),
                             array_merge (array ($this->fieldIdentifier,
                                                 $this->fieldPassword),
                                          $this->fieldsInfo));
    if (count ($data) === 0)
      throw new Exception ("Unable to find the user : '$email'", 401);
    if (! isset ($data[0][$this->fieldPassword]))
      throw new Exception ("Unable to get the user password from database",
                           500);
    $cryptedPassword = $data[0][$this->fieldPassword];
    if (crypt ($password, $cryptedPassword) !== $cryptedPassword)
      throw new Exception ("Bad password for '$email'", 401);
    unset ($data[0][$this->fieldPassword]);
    $this->details = $data[0];
  }

  /** Return all the parameters recorded for the authenticate user */
  public function getdetails ()
  {
    return $this->details;
  }

  /** Method to change the password
      @param string $oldpassword The old password (to check if the user have the
         rights to change the password)
      @param string $newpassword The new password to be recorded */
  public function changepassword ($oldpassword, $newpassword)
  {
    if ($this->db === null)
      throw new Exception ("The SQL database is not connected", 500);
    if ($this->details === null ||
        ! isset ($this->details[$this->fieldIdentifier]))
      throw new Exception (
                   "Can't change the password if the user is not authenticated",
                500);
    $data = $this->db->read (array (array ($this->fieldIdentifier, 
                                       $this->details[$this->fieldIdentifier])),
                             array_merge (array ($this->fieldIdentifier,
                                                 $this->fieldPassword),
                                          $this->fieldsInfo));
    $cryptedPassword = $data[0][$this->fieldPassword];
    if (crypt ($oldpassword, $cryptedPassword) !== $cryptedPassword)
      throw new Exception ("Bad old password provided", 401);
    $cost = 11;
    $salt=substr(base64_encode(openssl_random_pseudo_bytes(17)),0,22);
    $salt=str_replace("+",".",$salt);
    $param='$'.implode('$',array(
           "2y", //select the most secure version of blowfish (>=PHP 5.3.7)
           str_pad($cost,2,"0",STR_PAD_LEFT), //add the cost in two digits
           $salt //add the salt
    ));
    //now do the actual hashing
    $cryptpassword = crypt ($newpassword, $param);
    $rc = $this->db->update ($this->details[$this->fieldIdentifier], 
                             array ($this->fieldPassword => $cryptpassword));
    if ($rc !== 1)
      throw new Exception ("Can't change the password", 500);
  }

  /** Method to overwrite the password (without oldpassword check)
      Must be reserved to the administrators. For the users, use changepassword
      method
      @param string $email the user identifier to select
      @param string $newpassword The new password to be recorded */
  public function overwritepassword ($email, $newpassword)
  {
    if ($this->db === null)
      throw new Exception ("The SQL database is not connected", 500);
    $data = $this->db->read (array (array ($this->fieldIdentifier, $email)),
                             array_merge (array ($this->fieldIdentifier,
                                                 $this->fieldPassword),
                                          $this->fieldsInfo));
    if (count ($data) === 0)
      throw new Exception ("Unable to find the user : '$email'", 401);
    $cost = 11;
    $salt=substr(base64_encode(openssl_random_pseudo_bytes(17)),0,22);
    $salt=str_replace("+",".",$salt);
    $param='$'.implode('$',array(
           "2y", //select the most secure version of blowfish (>=PHP 5.3.7)
           str_pad($cost,2,"0",STR_PAD_LEFT), //add the cost in two digits
           $salt //add the salt
    ));
    //now do the actual hashing
    $cryptpassword = crypt ($newpassword, $param);
    $rc = $this->db->update ($email, 
                             array ($this->fieldPassword => $cryptpassword));
    if ($rc !== 1)
      throw new Exception ("Can't change the password", 500);
  }
  /** List all the users available in the database
      Return firstname, lastname, mail, with mail is an array */
  public function listusers ()
  {
    if ($this->db === null)
      throw new Exception ("The SQL database is not connected", 500);
    $data = $this->db->read (null, array_merge (array ($this->fieldIdentifier),
                                                $this->fieldsInfo));
    return $data;
  }
}