def _read_mem_bio(self, bio):
        """
        Reads a memory BIO. This only works on memory BIOs.
        """
        buf = self._ffi.new("char **")
        buf_len = self._lib.BIO_get_mem_data(bio, buf)
        self.openssl_assert(buf_len > 0)
        self.openssl_assert(buf[0] != self._ffi.NULL)
        bio_data = self._ffi.buffer(buf[0], buf_len)[:]
        return bio_data
dataset/ETHPy150Open cloudera/hue/desktop/core/ext-py/cryptography-1.3.1/src/cryptography/hazmat/backends/openssl/backend.py/Backend._read_mem_bio/original