SSL.py 文件源码

def set_alpn_protos(self, protos):
        """
        Specify the clients ALPN protocol list.

        These protocols are offered to the server during protocol negotiation.

        :param protos: A list of the protocols to be offered to the server.
            This list should be a Python list of bytestrings representing the
            protocols to offer, e.g. ``[b'http/1.1', b'spdy/2']``.
        """
        # Take the list of protocols and join them together, prefixing them
        # with their lengths.
        protostr = b''.join(
            chain.from_iterable((int2byte(len(p)), p) for p in protos)
        )

        # Build a C string from the list. We don't need to save this off
        # because OpenSSL immediately copies the data out.
        input_str = _ffi.new("unsigned char[]", protostr)
        input_str_len = _ffi.cast("unsigned", len(protostr))
        _lib.SSL_CTX_set_alpn_protos(self._context, input_str, input_str_len)