SocketTlsRead
SocketTlsRead
Read data from secure TLS connection.
int SocketTlsRead(
int socket, // socket
uchar& buffer[], // buffer for reading data from socket
uint buffer_maxlen // number of bytes to read
);Parameters
- socket
[in] Socket handle returned by the SocketCreate function. When an incorrect handle is passed to _LastError, the error 5270 (ERR_NETSOCKET_INVALIDHANDLE) is activated.
- buffer
[out] Reference to the uchar type array the data is read in. Dynamic array size is increased by the number of read bytes. The array size cannot exceed INT_MAX (2147483647).
- buffer_maxlen
[in] Number of bytes to read to the buffer[] array. Data not fitting into the array remain in the socket. They can be received by the next SocketTLSRead call. buffer_maxlen cannot exceed INT_MAX (2147483647).
Return Value
If successful, return the number of read bytes. In case of an error, -1 is returned.
Note
If an error occurs on a system socket when executing the function, connection established via SocketConnect is discontinued.
The function is executed till it receives the specified amount of data or the timeout is reached (SocketTimeouts).
In case of a data reading error, the error 5273 (ERR_NETSOCKET_IO_ERROR) is written in _LastError.
The function can be called only from Expert Advisors and scripts, as they run in their own execution threads. If calling from an indicator, GetLastError() returns the error 4014 – “Function is not allowed for call”.
Example:
//+------------------------------------------------------------------+
//| SocketExample.mq5 |
//| Copyright 2018, MetaQuotes Software Corp. |
//| https://www.mql5.com |
//+------------------------------------------------------------------+
#property copyright "Copyright 2000-2024, MetaQuotes Ltd."
#property link "https://www.mql5.com"
#property version "1.00"
#property description "Add Address to the list of allowed ones in the terminal settings to let the example work"
#property script_show_inputs
input string Address="www.mql5.com";
input int Port =80;
bool ExtTLS =false;
//+------------------------------------------------------------------+
//| Send command to the server |
//+------------------------------------------------------------------+
bool HTTPSend(int socket,string request)
{
char req[];
int len=StringToCharArray(request,req)-1;
if(len<0)
return(false);
//--- if secure TLS connection is used via the port 443
if(ExtTLS)
return(SocketTlsSend(socket,req,len)==len);
//--- if standard TCP connection is used
return(SocketSend(socket,req,len)==len);
}
//+------------------------------------------------------------------+
//| Read server response |
//+------------------------------------------------------------------+
bool HTTPRecv(int socket,uint timeout)
{
char rsp[];
string result;
uint timeout_check=GetTickCount()+timeout;
//--- read data from sockets till they are still present but not longer than timeout
do
{
uint len=SocketIsReadable(socket);
if(len)
{
int rsp_len;
//--- various reading commands depending on whether the connection is secure or not
if(ExtTLS)
rsp_len=SocketTlsRead(socket,rsp,len);
else
rsp_len=SocketRead(socket,rsp,len,timeout);
//--- analyze the response
if(rsp_len>0)
{
result+=CharArrayToString(rsp,0,rsp_len);
//--- print only the response header
int header_end=StringFind(result,"\r\n\r\n");
if(header_end>0)
{
Print("HTTP answer header received:");
Print(StringSubstr(result,0,header_end));
return(true);
}
}
}
}
while(GetTickCount()<timeout_check && !IsStopped());
return(false);
}
//+------------------------------------------------------------------+
//| Script program start function |
//+------------------------------------------------------------------+
void OnStart()
{
int socket=SocketCreate();
//--- check the handle
if(socket!=INVALID_HANDLE)
{
//--- connect if all is well
if(SocketConnect(socket,Address,Port,1000))
{
Print("Established connection to ",Address,":",Port);
string subject,issuer,serial,thumbprint;
datetime expiration;
//--- if connection is secured by the certificate, display its data
if(SocketTlsCertificate(socket,subject,issuer,serial,thumbprint,expiration))
{
Print("TLS certificate:");
Print(" Owner: ",subject);
Print(" Issuer: ",issuer);
Print(" Number: ",serial);
Print(" Print: ",thumbprint);
Print(" Expiration: ",expiration);
ExtTLS=true;
}
//--- send GET request to the server
if(HTTPSend(socket,"GET / HTTP/1.1\r\nHost: www.mql5.com\r\nUser-Agent: MT5\r\n\r\n"))
{
Print("GET request sent");
//--- read the response
if(!HTTPRecv(socket,1000))
Print("Failed to get a response, error ",GetLastError());
}
else
Print("Failed to send GET request, error ",GetLastError());
}
else
{
Print("Connection to ",Address,":",Port," failed, error ",GetLastError());
}
//--- close a socket after using
SocketClose(socket);
}
else
Print("Failed to create a socket, error ",GetLastError());
}
//+------------------------------------------------------------------+