Function SendHandshake

tools/websocket_to_posix_proxy/src/main.cpp:54–76

Sends WebSocket handshake back to the given WebSocket connection.

// Sends WebSocket handshake back to the given WebSocket connection.
void SendHandshake(int fd, const char *request) {
  const char webSocketGlobalGuid[] = "258EAFA5-E914-47DA-95CA-C5AB0DC85B11"; // 36 characters long
  char key[128+sizeof(webSocketGlobalGuid)];
  GetHttpHeader(request, "Sec-WebSocket-Key: ", key, sizeof(key)/2);
  strcat(key, webSocketGlobalGuid);

  char sha1[21];
  printf("hashing key: \"%s\"\n", key);
  SHA1(sha1, key, (int)strlen(key));

  char handshakeMsg[] = 
    "HTTP/1.1 101 Switching Protocols\r\n"
    "Upgrade: websocket\r\n"
    "Connection: Upgrade\r\n"
    "Sec-WebSocket-Accept: 0000000000000000000000000000\r\n"
    "\r\n";

  base64_encode(strstr(handshakeMsg, "Sec-WebSocket-Accept: ") + strlen("Sec-WebSocket-Accept: "), sha1, 20);

  int err = send(fd, handshakeMsg, (int)strlen(handshakeMsg), 0);
  if (err < 0) on_error("Client write failed\n");
  printf("Sent handshake:\n%s\n", handshakeMsg);
}

// Validates if the given, possibly partially received WebSocket message has
// enough bytes to contain a full WebSocket header.