sqlite3 driver for roundcube password plugin

sqlite3.php

<?php

/**
 * sqlite3 Password Driver
 *
 * Driver for passwords stored in sqlite3 database
 *
 * @version 0.8
 * @author John Kristensen <john@jerrykan.com>
 *
 */

function password_save($curpass, $passwd)
{
    $rcmail = rcmail::get_instance();

    if (!($sql = $rcmail->config->get('password_query')))
        $sql = 'SELECT update_passwd(%c, %u)';

    if ($dsn = $rcmail->config->get('password_db_dsn')) {
        $db = new PDO($dsn);
    } else {
        $db = $rcmail->get_dbh();
    }

    if ($err = $db->errorCode())
        return PASSWORD_ERROR;

    // crypted password
    if (strpos($sql, '%c') !== FALSE) {
        $salt = '';
        if (CRYPT_MD5) {
            // Always use eight salt characters for MD5 (#1488136)
    	    $len = 8;
        } else if (CRYPT_STD_DES) {
    	    $len = 2;
        } else {
    	    return PASSWORD_CRYPT_ERROR;
        }

        //Restrict the character set used as salt (#1488136)
        $seedchars = './0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz';
        for ($i = 0; $i < $len ; $i++) {
    	    $salt .= $seedchars[rand(0, 63)];
        }

        $sql = str_replace('%c',  $db->quote(crypt($passwd, CRYPT_MD5 ? '$1$'.$salt.'$' : $salt)), $sql);
    }

    // dovecotpw
    if (strpos($sql, '%D') !== FALSE) {
        if (!($dovecotpw = $rcmail->config->get('password_dovecotpw')))
            $dovecotpw = 'dovecotpw';
        if (!($method = $rcmail->config->get('password_dovecotpw_method')))
            $method = 'CRAM-MD5';

        // use common temp dir
        $tmp_dir = $rcmail->config->get('temp_dir');
        $tmpfile = tempnam($tmp_dir, 'roundcube-');

        $pipe = popen("$dovecotpw -s '$method' > '$tmpfile'", "w");
        if (!$pipe) {
            unlink($tmpfile);
            return PASSWORD_CRYPT_ERROR;
        }
        else {
            fwrite($pipe, $passwd . "\n", 1+strlen($passwd)); usleep(1000);
            fwrite($pipe, $passwd . "\n", 1+strlen($passwd));
            pclose($pipe);
            $newpass = trim(file_get_contents($tmpfile), "\n");
            if (!preg_match('/^\{' . $method . '\}/', $newpass)) {
                return PASSWORD_CRYPT_ERROR;
            }
            if (!$rcmail->config->get('password_dovecotpw_with_method'))
                $newpass = trim(str_replace('{' . $method . '}', '', $newpass));
            unlink($tmpfile);
        }
        $sql = str_replace('%D', $db->quote($newpass), $sql);
    }

    // hashed passwords
    if (preg_match('/%[n|q]/', $sql)) {
        if (!extension_loaded('hash')) {
            raise_error(array(
                'code' => 600,
	            'type' => 'php',
	            'file' => __FILE__, 'line' => __LINE__,
                'message' => "Password plugin: 'hash' extension not loaded!"
            ), true, false);

            return PASSWORD_ERROR;
        }

        if (!($hash_algo = strtolower($rcmail->config->get('password_hash_algorithm'))))
            $hash_algo = 'sha1';

        $hash_passwd = hash($hash_algo, $passwd);
        $hash_curpass = hash($hash_algo, $curpass);

        if ($rcmail->config->get('password_hash_base64')) {
            $hash_passwd = base64_encode(pack('H*', $hash_passwd));
            $hash_curpass = base64_encode(pack('H*', $hash_curpass));
        }

        $sql = str_replace('%n', $db->quote($hash_passwd, PDO::PARAM_STR), $sql);
        $sql = str_replace('%q', $db->quote($hash_curpass, PDO::PARAM_STR), $sql);
    }

    // Handle clear text passwords securely (#1487034)
    $sql_vars = array();
    if (preg_match_all('/%[p|o]/', $sql, $m)) {
        foreach ($m[0] as $var) {
            if ($var == '%p') {
                $sql = preg_replace('/%p/', '?', $sql, 1);
                $sql_vars[] = (string) $passwd;
            }
            else { // %o
                $sql = preg_replace('/%o/', '?', $sql, 1);
                $sql_vars[] = (string) $curpass;
            }
        }
    }

    $local_part  = $rcmail->user->get_username('local');
    $domain_part = $rcmail->user->get_username('domain');
    $username    = $_SESSION['username'];
    $host        = $_SESSION['imap_host'];

    // convert domains to/from punnycode
    if ($rcmail->config->get('password_idn_ascii')) {
        $domain_part = rcube_idn_to_ascii($domain_part);
        $username    = rcube_idn_to_ascii($username);
        $host        = rcube_idn_to_ascii($host);
    }
    else {
        $domain_part = rcube_idn_to_utf8($domain_part);
        $username    = rcube_idn_to_utf8($username);
        $host        = rcube_idn_to_utf8($host);
    }

    // at least we should always have the local part
    $sql = str_replace('%l', $db->quote($local_part, PDO::PARAM_STR), $sql);
    $sql = str_replace('%d', $db->quote($domain_part, PDO::PARAM_STR), $sql);
    $sql = str_replace('%u', $db->quote($username, PDO::PARAM_STR), $sql);
    $sql = str_replace('%h', $db->quote($host, PDO::PARAM_STR), $sql);

    $res = $db->prepare($sql);
    $res->execute($sql_vars);

    if (!intval($res->errorCode())) {
        if (strtolower(substr(trim($query),0,6))=='select') {
    	    if ($result = $res->fetchAll())
	            return PASSWORD_SUCCESS;
        } else {
            // This is the good case: 1 row updated
    	    if ($res->rowCount() == 1)
                return PASSWORD_SUCCESS;
            // @TODO: Some queries don't affect any rows
            // Should we assume a success if there was no error?
        }
    }

    return PASSWORD_ERROR;
}

?>

What this can be used for?