C++

Upgrade a Plain TCP Connection to TLS

Demonstrates Socket.ConvertToSsl, which upgrades an already-connected plain TCP socket to TLS by performing a client-side TLS handshake over the existing connection.

Background. This supports STARTTLS-style upgrades, where a protocol begins in plaintext and switches to TLS at a defined point. Perform the protocol-specific negotiation first, then call ConvertToSsl.

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C++

#include <CkSocket.h>

void ChilkatSample(void)
    {
    bool success = false;

    CkSocket socket;

    //  Connect as plain TCP (no TLS yet).
    bool bTls = false;
    int maxWaitMs = 5000;
    success = socket.Connect("example.com",5000,bTls,maxWaitMs);
    if (success == false) {
        std::cout << socket.lastErrorText() << "\r\n";
        return;
    }

    //  At the point where the application protocol permits a STARTTLS-style upgrade, perform any required
    //  negotiation, then upgrade the existing connection to TLS with a client-side handshake.
    success = socket.ConvertToSsl();
    if (success == false) {
        std::cout << socket.lastErrorText() << "\r\n";
        return;
    }

    std::cout << "Connection upgraded to TLS." << "\r\n";
    }