securecookie.py 文件源码

def serialize(self, expires=None):
        """Serialize the secure cookie into a string.

        If expires is provided, the session will be automatically invalidated
        after expiration when you unseralize it. This provides better
        protection against session cookie theft.

        :param expires: an optional expiration date for the cookie (a
                        :class:`datetime.datetime` object)
        """
        if self.secret_key is None:
            raise RuntimeError('no secret key defined')
        if expires:
            self['_expires'] = _date_to_unix(expires)
        result = []
        mac = hmac(self.secret_key, None, self.hash_method)
        for key, value in sorted(self.items()):
            result.append(('%s=%s' % (
                url_quote_plus(key),
                self.quote(value).decode('ascii')
            )).encode('ascii'))
            mac.update(b'|' + result[-1])
        return b'?'.join([
            base64.b64encode(mac.digest()).strip(),
            b'&'.join(result)
        ])