(Unicode C) Examine Client Certificates for an Accepted TLS Connection

Demonstrates how to access the client certificates for a TLS connection accepted by your application acting as the server.

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#include <C_CkSocketW.h>
#include <C_CkCertW.h>

void ChilkatSample(void)
    {
    HCkSocketW listenSslSocket;
    HCkCertW cert;
    BOOL success;
    int myPort;
    int backLog;
    int maxWaitMillisec;
    HCkSocketW clientSock;
    int numClientCerts;
    int i;
    HCkCertW clientCert;

    // This example requires the Chilkat API to have been previously unlocked.
    // See Global Unlock Sample for sample code.

    listenSslSocket = CkSocketW_Create();

    // An SSL/TLS server needs a digital certificate.  This example loads it from a PFX file.
    // This is the server's certificate.

    cert = CkCertW_Create();
    success = CkCertW_LoadPfxFile(cert,L"qa_data/serverCert/myServerCert.pfx",L"pfx_password");
    if (success != TRUE) {
        wprintf(L"%s\n",CkCertW_lastErrorText(cert));
        CkSocketW_Dispose(listenSslSocket);
        CkCertW_Dispose(cert);
        return;
    }

    // To accept client client certificates in the TLS handshake,
    // we must indicate a list of acceptable client certificate root CA DN's
    // that are allowed.  (DN is an acronym for Distinguished Name.)
    // Call AddSslAcceptableClientCaDn once for each acceptable CA DN.
    // Here are a few examples so you can see the general format of a DN.
    CkSocketW_AddSslAcceptableClientCaDn(listenSslSocket,L"C=SE, O=AddTrust AB, OU=AddTrust External TTP Network, CN=AddTrust External CA Root");
    CkSocketW_AddSslAcceptableClientCaDn(listenSslSocket,L"O=Digital Signature Trust Co., CN=DST Root CA X3");

    // Initialize with our server's TLS certificate.
    success = CkSocketW_InitSslServer(listenSslSocket,cert);
    if (success != TRUE) {
        wprintf(L"%s\n",CkSocketW_lastErrorText(listenSslSocket));
        CkSocketW_Dispose(listenSslSocket);
        CkCertW_Dispose(cert);
        return;
    }

    // Bind and listen on a port:
    myPort = 8123;
    // Allow for a max of 5 queued connect requests.
    backLog = 5;
    success = CkSocketW_BindAndListen(listenSslSocket,myPort,backLog);
    if (success != TRUE) {
        wprintf(L"%s\n",CkSocketW_lastErrorText(listenSslSocket));
        CkSocketW_Dispose(listenSslSocket);
        CkCertW_Dispose(cert);
        return;
    }

    // Accept the next incoming connection.
    maxWaitMillisec = 20000;
    clientSock = CkSocketW_AcceptNextConnection(listenSslSocket,maxWaitMillisec);
    if (CkSocketW_getLastMethodSuccess(listenSslSocket) == FALSE) {
        wprintf(L"%s\n",CkSocketW_lastErrorText(listenSslSocket));
        CkSocketW_Dispose(listenSslSocket);
        CkCertW_Dispose(cert);
        return;
    }

    // Examine the client certs chain.  The 1st cert will be the client certificate, and
    // the subsequent certs will be the certs in the chain of authentication.
    numClientCerts = CkSocketW_getNumReceivedClientCerts(clientSock);
    wprintf(L"numClientCerts = %d\n",numClientCerts);

    i = 0;
    while (i < numClientCerts) {
        clientCert = CkSocketW_GetReceivedClientCert(clientSock,i);
        wprintf(L"%s\n",CkCertW_subjectDN(clientCert));
        CkCertW_Dispose(clientCert);
        i = i + 1;
    }

    // Close the connection with the client
    success = CkSocketW_Close(clientSock,1000);

    CkSocketW_Dispose(clientSock);


    CkSocketW_Dispose(listenSslSocket);
    CkCertW_Dispose(cert);

    }