read_websocket_frame() resized the payload to the length a frame header
declared before reading any of it, so a 14-byte header made the peer
allocate and zero-fill up to CPPHTTPLIB_WEBSOCKET_MAX_PAYLOAD_LENGTH and
hold it until the read timed out. 70 such headers took a server to over
1 GB, and a client reading from a hostile server was exposed the same way.
Read the payload in CPPHTTPLIB_RECV_BUFSIZ chunks and grow it by each one,
so memory follows the bytes that actually came in.
yhirose
344311c1c3
