<?php
/**
 * Authentication against PAM with pwauth
 *
 * @package   davical
 * @category  Technical
 * @subpackage authentication/drivers
 * @author    Eric Seigne <eric.seigne@ryxeo.com>,
 *            Michael B. Trausch <mike@trausch.us>,
 *            Andrew McMillan <andrew@mcmillan.net.nz>
 * @copyright Eric Seigne
 * @license   http://gnu.org/copyleft/gpl.html GNU GPL v2 or later
 *
 * Based on drivers_squid_pam.php
 */

require_once("auth-functions.php");

/**
 * Plugin to authenticate against PAM with pwauth
 */
class pwauthPamDriver
{
  /**#@+
   * @access private
   */

  /**#@-*/


  /**
   * The constructor
   *
   * @param string $config path where pwauth is
   */
  function __construct($config)
  {
    global $c;
    if(!file_exists($config)) {
      $c->messages[] = sprintf(i18n('drivers_pwauth_pam : Unable to find %s file'), $config);
      $this->valid=false;
      return ;
    }
  }
}


/**
 * Check the username / password against the PAM system
 */
function PWAUTH_PAM_check($username, $password) {
  global $c;
  $program = $c->authenticate_hook['config']['path'];
  $email_base = $c->authenticate_hook['config']['email_base'];

  $pipe = popen(escapeshellarg($program), 'w');
  $authinfo = sprintf("%s\n%s\n", $username, $password);
  $written = fwrite($pipe, $authinfo);
  dbg_error_log('PAM', 'Bytes written: %d of %d', $written, strlen($authinfo));
  $return_status = pclose($pipe);

  switch($return_status) {
    case 0:
      // STATUS_OK: Authentication succeeded.
      dbg_error_log('PAM', 'User %s successfully authenticated', $username);
      $principal = new Principal('username',$username);
      if ( !$principal->Exists() ) {
        dbg_error_log('PAM', 'User %s does not exist in local db, creating', $username);
        $pwent = posix_getpwnam($username);
        $gecos = explode(',',$pwent['gecos']);
        $fullname = $gecos[0];
        $principal->Create( array(
                              'username' => $username,
                              'user_active' => 't',
                              'email' => sprintf('%s@%s', $username, $email_base),
                              'fullname' => $fullname
                          ));
        if ( ! $principal->Exists() ) {
          dbg_error_log( "PAM", "Unable to create local principal for '%s'", $username );
          return false;
        }
        CreateHomeCollections($username);
	CreateDefaultRelationships($username);
      }
      return $principal;
      break;

    /*
     * Note that for system configurations using PAM instead of
     * reading the password database directly, if PAM is unable to
     * read the password database, pwauth will return status 1.
     */
    case 1:
    case 2:
      // (1) STATUS_UNKNOWN: Invalid username or password.
      // (2) STATUS_INVALID: Invalid password.
      dbg_error_log('PAM', 'Invalid username or password (username: %s)', $username);
      break;

    case 3:
      // STATUS_BLOCKED: UID for username is < pwauth's MIN_UNIX_UID
      dbg_error_log('PAM', 'UID for username %s is < pwauth MIN_UNIX_UID', $username);
      break;

    case 4:
      // STATUS_EXPIRED: The user account has expired.
      dbg_error_log('PAM', 'The account for %s has expired', $username);
      break;

    case 5:
      // STATUS_PW_EXPIRED: The user account's password has expired.
      dbg_error_log('PAM', 'The account password for user %s has expired', $username);
      break;

    case 6:
      // STATUS_NOLOGIN: Logins to the system are administratively disabled.
      dbg_error_log('PAM', 'Logins administratively disabled (%s)', $username);
      break;

    case 7:
      // STATUS_MANYFAILS: Too many login failures for user account.
      dbg_error_log('PAM', 'Login rejected for %s, too many failures', $username);
      break;

    case 50:
      // STATUS_INT_USER: Configuration error, Web server cannot use pwauth
      dbg_error_log('PAM', 'config error: see pwauth man page (%s)', 'STATUS_INT_USER');
      break;

    case 51:
      // STATUS_INT_ARGS: pwauth received no username/passwd to check
      dbg_error_log('PAM', 'error: pwauth received no username/password');
      break;

    case 52:
      // STATUS_INT_ERR: unknown error
      dbg_error_log('PAM', 'error: see pwauth man page (%s)', 'STATUS_INT_ERR');
      break;

    case 53:
      // STATUS_INT_NOROOT: pwauth could not read the password database
      dbg_error_log('PAM', 'config error: cannot read password database (%s)', 'STATUS_INT_NOROOT');
      break;

    default:
      // Unknown error code.
      dbg_error_log('PAM', 'An unknown error (%d) has occurred', $return_status);
  }

  return(FALSE);
}