_resResolver(resResolver) {

_socket = -1;

_addrLen = 0;

_ssl = NULL;

_bufferProcessed = 0;

_bufferUnusedIdx = 0;

_connectionState = STATE_UNDEFINED;

_clientState = CSTATE_UNDEFINED;

_httpHeaders = NULL;

_defaultHeaders = NULL;

_isKeepAlive = false;

_lastTransmissionTS = millis();

_shutdownTS = 0;

if (_connectionState == STATE_UNDEFINED) {

_defaultHeaders = defaultHeaders;

_socket = accept(serverSocketID, (struct sockaddr * )&_sockAddr, &_addrLen);

// Build up SSL Connection context if the socket has been created successfully

if (_socket >= 0) {

HTTPS_DLOGHEX("[-->] New connection. Socket fid is: ", _socket);

_ssl = SSL_new(sslCtx);

if (_ssl) {

// Bind SSL to the socket

int success = SSL_set_fd(_ssl, _socket);

if (success) {

// Perform the handshake

success = SSL_accept(_ssl);

if (success) {

_connectionState = STATE_INITIAL;

_httpHeaders = new HTTPHeaders();

refreshTimeout();

return _socket;

} else {

HTTPS_DLOG("[ERR] SSL_accept failed. Aborting handshake.");

}

} else {

HTTPS_DLOG("[ERR] SSL_set_fd failed. Aborting handshake.");

}

} else {

HTTPS_DLOG("[ERR] SSL_new failed. Aborting handshake.");

}

} else {

HTTPS_DLOG("[ERR] Could not accept() new connection");

}

_connectionState = STATE_ERROR;

_clientState = CSTATE_ACTIVE;

// This will only be called if the connection could not be established and cleanup

// variables like _ssl etc.

closeConnection();

}

// Error: The connection has already been established or could not be established

return -1;

// TODO: Call an event handler here, maybe?

if (_connectionState != STATE_ERROR && _connectionState != STATE_CLOSED) {

// First call to closeConnection - set the timestamp to calculate the timeout later on

if (_connectionState != STATE_CLOSING) {

_shutdownTS = millis();

}

// Set the connection state to closing. We stay in closing as long as SSL has not been shutdown

// correctly

_connectionState = STATE_CLOSING;

}

// Try to tear down SSL while we are in the _shutdownTS timeout period or if an error occurred

if (_ssl) {

if(_connectionState == STATE_ERROR || SSL_shutdown(_ssl) == 0) {

// SSL_shutdown will return 1 as soon as the client answered with close notify

// This means we are safe to close the socket

SSL_free(_ssl);

_ssl = NULL;

} else if (_shutdownTS + HTTPS_SHUTDOWN_TIMEOUT < millis()) {

// The timeout has been hit, we force SSL shutdown now by freeing the context

SSL_free(_ssl);

_ssl = NULL;

HTTPS_DLOG("[ERR] SSL_shutdown did not receive close notification from the client");

_connectionState = STATE_ERROR;

}

}

// If SSL has been brought down, close the socket

if (!_ssl) {

// Tear down the socket

if (_socket >= 0) {

HTTPS_DLOGHEX("[<--] Connection has been closed. fid = ", _socket);

close(_socket);

_socket = -1;

_addrLen = 0;

}

if (_connectionState != STATE_ERROR) {

_connectionState = STATE_CLOSED;

}

if (_httpHeaders != NULL) {

delete _httpHeaders;

_httpHeaders = NULL;

}

}

if (!isClosed()) {

// If there is buffer data that has been marked as processed.

// Some example is shown here:

//

// Previous configuration:

// GET / HTTP/1.1\\Host: test\\Foo: bar\\\\[some uninitialized memory]

// ^ processed ^ unusedIdx

//

// New configuration after shifting:

// Host: test\\Foo: bar\\\\[some uninitialized memory]

// ^ processed ^ unusedIdx

if (_bufferProcessed > 0) {

for(int i = 0; i < HTTPS_CONNECTION_DATA_CHUNK_SIZE; i++) {

int copyFrom = i + _bufferProcessed;

if (copyFrom < _bufferUnusedIdx) {

_receiveBuffer[i] = _receiveBuffer[copyFrom];

} else {

break;

}

}

_bufferUnusedIdx -= _bufferProcessed;

_bufferProcessed = 0;

}

if (_bufferUnusedIdx < HTTPS_CONNECTION_DATA_CHUNK_SIZE) {

// Check only this socket for data

fd_set sockfds;

FD_ZERO( &sockfds );

FD_SET(_socket, &sockfds);

// We define an immediate timeout (return immediately, if there's no data)

timeval timeout;

timeout.tv_sec = 0;

timeout.tv_usec = 0;

// Check for input

// As by 2017-12-14, it seems that FD_SETSIZE is defined as 0x40, but socket IDs now

// start at 0x1000, so we need to use _socket+1 here

select(_socket + 1, &sockfds, NULL, NULL, &timeout);

if (FD_ISSET(_socket, &sockfds) || SSL_pending(_ssl) > 0) {

HTTPS_DLOGHEX("[ ] There is data on the connection socket. fid=", _socket)

// The return code of SSL_read means:

// > 0 : Length of the data that has been read

// < 0 : Error

// = 0 : Connection closed

int readReturnCode = SSL_read(

_ssl,

// Only after the part of the buffer that has not been processed yet

_receiveBuffer + sizeof(char) * _bufferUnusedIdx,

// Only append up to the end of the buffer

HTTPS_CONNECTION_DATA_CHUNK_SIZE - _bufferUnusedIdx

);

if (readReturnCode > 0) {

_bufferUnusedIdx += readReturnCode;

refreshTimeout();

return readReturnCode;

} else if (readReturnCode == 0) {

// The connection has been closed by the client

_clientState = CSTATE_CLOSED;

HTTPS_DLOGHEX("[ x ] Client closed connection, fid=", _socket);

// TODO: If we are in state websocket, we might need to do something here

return 0;

} else {

// An error occured

_connectionState = STATE_ERROR;

HTTPS_DLOGHEX("[ERR] An SSL error occured, fid=", _socket);

closeConnection();

return -1;

}

} // data pending

} // buffer can read more

}

return 0;

updateBuffer();

size_t bufferSize = _bufferUnusedIdx - _bufferProcessed;

if (length > bufferSize) {

length = bufferSize;

}

// Write until length is reached (either by param of by empty buffer

for(int i = 0; i < length; i++) {

buffer[i] = _receiveBuffer[_bufferProcessed++];

}

return length;

_connectionState = STATE_ERROR;

// TODO: Write 500

Serial.println("Server error");

char staticResponse[] = "HTTP/1.1 500 Internal Server Error\r\nServer: esp32https\r\nConnection:close\r\nContent-Type: text/html\r\nContent-Length:34\r\n\r\n<h1>500 Internal Server Error</h1>";

SSL_write(_ssl, staticResponse, strlen(staticResponse));

closeConnection();

_connectionState = STATE_ERROR;

// TODO: Write 400

Serial.println("Client error");

char staticResponse[] = "HTTP/1.1 400 Bad Request\r\nServer: esp32https\r\nConnection:close\r\nContent-Type: text/html\r\nContent-Length:26\r\n\r\n<h1>400 Bad Request</h1>";

SSL_write(_ssl, staticResponse, strlen(staticResponse));

closeConnection();

while(_bufferProcessed < _bufferUnusedIdx) {

char newChar = _receiveBuffer[_bufferProcessed];

if ( newChar == '\r') {

// Look ahead for \n (if not possible, wait for next round

if (_bufferProcessed+1 < _bufferUnusedIdx) {

if (_receiveBuffer[_bufferProcessed+1] == '\n') {

_bufferProcessed += 2;

_parserLine.parsingFinished = true;

return;

} else {

// Line has not been terminated by \r\n

HTTPS_DLOG("[ERR] Line that has not been terminated by \\r\\n (got only \\r). Client error.");

clientError();

return;

}

}

} else {

_parserLine.text += newChar;

_bufferProcessed += 1;

}

// Check that the max request string size is not exceeded

if (_parserLine.text.length() > lengthLimit) {

HTTPS_DLOG("[ERR] Line length exceeded. Server error.");

serverError();

return;

}

}

// First, update the buffer

// newByteCount will contain the number of new bytes that have to be processed

updateBuffer();

if (_clientState == CSTATE_CLOSED) {

HTTPS_DLOGHEX("[ ] Client closed in state", _clientState)

}

if (_clientState == CSTATE_CLOSED && _bufferProcessed == _bufferUnusedIdx && _connectionState < STATE_HEADERS_FINISHED) {

closeConnection();

}

if (!isClosed() && isTimeoutExceeded()) {

HTTPS_DLOGHEX("[zZz] Connection timeout exceeded, closing connection. fid=", _socket)

closeConnection();

}

if (!isError()) {

// State machine (Reading request, reading headers, ...)

switch(_connectionState) {

case STATE_INITIAL: // Read request line

readLine(HTTPS_REQUEST_MAX_REQUEST_LENGTH);

if (_parserLine.parsingFinished && !isClosed()) {

// Find the method

size_t spaceAfterMethodIdx = _parserLine.text.find(' ');

if (spaceAfterMethodIdx == std::string::npos) {

HTTPS_DLOG("[ERR] Missing space after HTTP method. Client Error.")

clientError();

break;

}

_httpMethod = _parserLine.text.substr(0, spaceAfterMethodIdx);

// Find the resource string:

size_t spaceAfterResourceIdx = _parserLine.text.find(' ', spaceAfterMethodIdx + 1);

if (spaceAfterResourceIdx == std::string::npos) {

HTTPS_DLOG("[ERR] Missing space after HTTP resource. Client Error.")

clientError();

break;

}

_httpResource = _parserLine.text.substr(spaceAfterMethodIdx + 1, spaceAfterResourceIdx - _httpMethod.length() - 1);

_parserLine.parsingFinished = false;

_parserLine.text = "";

HTTPS_DLOG(("[ ] Request line finished: method="+_httpMethod+", resource="+_httpResource).c_str());

_connectionState = STATE_REQUEST_FINISHED;

}

break;

case STATE_REQUEST_FINISHED: // Read headers

while (_bufferProcessed < _bufferUnusedIdx && !isClosed()) {

readLine(HTTPS_REQUEST_MAX_HEADER_LENGTH);

if (_parserLine.parsingFinished && _connectionState != STATE_ERROR) {

if (_parserLine.text.empty()) {

HTTPS_DLOG("[ ] Headers finished");

_connectionState = STATE_HEADERS_FINISHED;

// Break, so that the rest of the body does not get flushed through

_parserLine.parsingFinished = false;

_parserLine.text = "";

break;

} else {

int idxColon = _parserLine.text.find(':');

if ( (idxColon != std::string::npos) && (_parserLine.text[idxColon+1]==' ') ) {

_httpHeaders->set(new HTTPHeader(

_parserLine.text.substr(0, idxColon),

_parserLine.text.substr(idxColon+2)

));

} else {

HTTPS_DLOG("Malformed header line detected. Client error.");

HTTPS_DLOG(_parserLine.text.c_str());

clientError();

break;

}

}

_parserLine.parsingFinished = false;

_parserLine.text = "";

}

}

break;

case STATE_HEADERS_FINISHED: // Handle body

{

HTTPS_DLOG("[ ] Resolving resource...");

ResolvedResource resolvedResource;

_resResolver->resolveNode(_httpMethod, _httpResource, resolvedResource);

if (resolvedResource.didMatch()) {

// Did the client request connection:keep-alive?

HTTPHeader * connectionHeader = _httpHeaders->get("Connection");

if (connectionHeader != NULL && std::string("keep-alive").compare(connectionHeader->_value)==0) {

HTTPS_DLOGHEX("[ ] Keep-Alive activated. fid=", _socket);

_isKeepAlive = true;

} else {

HTTPS_DLOGHEX("[ ] Keep-Alive disabled. fid=", _socket);

_isKeepAlive = false;

}

// Create request context

HTTPRequest req = HTTPRequest(this, _httpHeaders, resolvedResource.getParams());

HTTPResponse res = HTTPResponse(this);

// Add default headers to the response

auto allDefaultHeaders = _defaultHeaders->getAll();

for(std::vector<HTTPHeader*>::iterator header = allDefaultHeaders->begin(); header != allDefaultHeaders->end(); ++header) {

res.setHeader((*header)->_name, (*header)->_value);

}

// Call the callback

HTTPS_DLOG("[ ] Calling handler function");

resolvedResource.getMatchingNode()->_callback(&req, &res);

// The callback-function should have read all of the request body.

// However, if it does not, we need to clear the request body now,

// because otherwise it would be parsed in the next request.

if (!req.requestComplete()) {

HTTPS_DLOG("[ERR] Callback function did not parse full request body");

req.discardRequestBody();

}

// Handling the request is done

HTTPS_DLOG("[ ] Handler function done, request complete");

// Now we need to check if we can use keep-alive to reuse the SSL connection

// However, if the client did not set content-size or defined connection: close,

// we have no chance to do so.

if (!_isKeepAlive) {

// No KeepAlive -> We are done. Transition to next state.

if (!isClosed()) {

_connectionState = STATE_BODY_FINISHED;

}

} else {

if (res.isResponseBuffered()) {

// If the response could be buffered:

res.setHeader("Connection", "keep-alive");

res.finalize();

if (_clientState != CSTATE_CLOSED) {

// Refresh the timeout for the new request

refreshTimeout();

// Reset headers for the new connection

_httpHeaders->clearAll();

// Go back to initial state

_connectionState = STATE_INITIAL;

}

}

// The response could not be buffered or the client has closed:

if (!isClosed() && _connectionState!=STATE_INITIAL) {

_connectionState = STATE_BODY_FINISHED;

}

}

} else {

HTTPS_DLOG("[ERR] Could not find a matching resource. Server error.");

serverError();

}

}

break;

case STATE_BODY_FINISHED: // Request is complete

closeConnection();

break;

case STATE_CLOSING: // As long as we are in closing state, we call closeConnection() again and wait for it to finish or timeout

closeConnection();

break;

case STATE_WEBSOCKET: // Do handling of the websocket

break;

default:;

}

}