Set a TLS Client Certificate for IMAP

See more IMAP Examples

Demonstrates the Chilkat Imap.SetSslClientCert method, which supplies a client certificate for TLS client-certificate authentication. The only argument is a Cert object that must provide access to its private key. Call it before connecting. This example loads the certificate from a PFX file.

Note: The certificate path is relative to the application's current working directory. Supply the path to your own certificate file.

Background: Most IMAP servers authenticate with a username and password only. A few high-security deployments additionally require mutual TLS, where the client presents its own certificate during the handshake. Because that happens as part of connecting, the certificate must be set before Connect — setting it afterward has no effect on the already-established connection.

Chilkat C Downloads

Download Chilkat for C

#include <C_CkImap.h>
#include <C_CkCert.h>

void ChilkatSample(void)
    {
    BOOL success;
    HCkImap imap;
    const char *pfxPassword;
    HCkCert cert;

    success = FALSE;

    //  Demonstrates the Imap.SetSslClientCert method, which supplies a client certificate for TLS
    //  client-certificate authentication.  The only argument is a Cert object.  It must be called
    //  before connecting.

    imap = CkImap_Create();

    CkImap_putSsl(imap,TRUE);
    CkImap_putPort(imap,993);

    //  The PFX password is not hard-coded in source.  Insert code here to obtain it from an
    //  interactive prompt, environment variable, or a secrets vault.

    //  Load the client certificate (and its private key) from a PFX file.
    cert = CkCert_Create();
    success = CkCert_LoadPfxFile(cert,"qa_data/client.pfx",pfxPassword);
    if (success == FALSE) {
        printf("%s\n",CkCert_lastErrorText(cert));
        CkImap_Dispose(imap);
        CkCert_Dispose(cert);
        return;
    }

    //  Provide the client certificate BEFORE connecting.
    success = CkImap_SetSslClientCert(imap,cert);
    if (success == FALSE) {
        printf("%s\n",CkImap_lastErrorText(imap));
        CkImap_Dispose(imap);
        CkCert_Dispose(cert);
        return;
    }

    success = CkImap_Connect(imap,"imap.example.com");
    if (success == FALSE) {
        printf("%s\n",CkImap_lastErrorText(imap));
        CkImap_Dispose(imap);
        CkCert_Dispose(cert);
        return;
    }

    success = CkImap_Login(imap,"user@example.com","myPassword");
    if (success == FALSE) {
        printf("%s\n",CkImap_lastErrorText(imap));
        CkImap_Dispose(imap);
        CkCert_Dispose(cert);
        return;
    }

    success = CkImap_Disconnect(imap);
    if (success == FALSE) {
        printf("%s\n",CkImap_lastErrorText(imap));
        CkImap_Dispose(imap);
        CkCert_Dispose(cert);
        return;
    }



    CkImap_Dispose(imap);
    CkCert_Dispose(cert);

    }