chrmorandi / yii2-ldap

        // Per RFC 4514, leading/trailing spaces should be encoded in DNs, as well as carriage returns.

        if ((int)$flags & LDAP_ESCAPE_DN) {

            if (!empty($value) && $value[0] === ' ') {

                $value = '\\20' . substr($value, 1);

            }

            if (!empty($value) && $value[strlen($value) - 1] === ' ') {

                $value = substr($value, 0, -1) . '\\20';

            }

            if (!empty($value) && $value[0] === ' ') {

                $value = '\\20' . substr($value, 1);

            }

            if (!empty($value) && $value[strlen($value) - 1] === ' ') {

                $value = substr($value, 0, -1) . '\\20';

            }

            // Only carriage returns seem to be valid, not line feeds (per testing of AD anyway).

            $value = str_replace("\r", '\0d', $value);

        }