(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_CkSocket.h>
#include <C_CkCert.h>

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

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

    listenSslSocket = CkSocket_Create();

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

    cert = CkCert_Create();
    success = CkCert_LoadPfxFile(cert,"qa_data/serverCert/myServerCert.pfx","pfx_password");
    if (success != TRUE) {
        printf("%s\n",CkCert_lastErrorText(cert));
        CkSocket_Dispose(listenSslSocket);
        CkCert_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.
    CkSocket_AddSslAcceptableClientCaDn(listenSslSocket,"C=SE, O=AddTrust AB, OU=AddTrust External TTP Network, CN=AddTrust External CA Root");
    CkSocket_AddSslAcceptableClientCaDn(listenSslSocket,"O=Digital Signature Trust Co., CN=DST Root CA X3");

    // Initialize with our server's TLS certificate.
    success = CkSocket_InitSslServer(listenSslSocket,cert);
    if (success != TRUE) {
        printf("%s\n",CkSocket_lastErrorText(listenSslSocket));
        CkSocket_Dispose(listenSslSocket);
        CkCert_Dispose(cert);
        return;
    }

    // Bind and listen on a port:
    myPort = 8123;
    // Allow for a max of 5 queued connect requests.
    backLog = 5;
    success = CkSocket_BindAndListen(listenSslSocket,myPort,backLog);
    if (success != TRUE) {
        printf("%s\n",CkSocket_lastErrorText(listenSslSocket));
        CkSocket_Dispose(listenSslSocket);
        CkCert_Dispose(cert);
        return;
    }

    // Accept the next incoming connection.
    maxWaitMillisec = 20000;
    clientSock = CkSocket_AcceptNextConnection(listenSslSocket,maxWaitMillisec);
    if (CkSocket_getLastMethodSuccess(listenSslSocket) == FALSE) {
        printf("%s\n",CkSocket_lastErrorText(listenSslSocket));
        CkSocket_Dispose(listenSslSocket);
        CkCert_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 = CkSocket_getNumReceivedClientCerts(clientSock);
    printf("numClientCerts = %d\n",numClientCerts);

    i = 0;
    while (i < numClientCerts) {
        clientCert = CkSocket_GetReceivedClientCert(clientSock,i);
        printf("%s\n",CkCert_subjectDN(clientCert));
        CkCert_Dispose(clientCert);
        i = i + 1;
    }

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

    CkSocket_Dispose(clientSock);


    CkSocket_Dispose(listenSslSocket);
    CkCert_Dispose(cert);

    }