(Unicode C) IMAP Download and Verify Signed (S/MIME) Email

Demonstrates how to download and verify digitally signed S/MIME email.

Note: This example requires Chilkat v11.0.0 or greater.

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#include <C_CkImapW.h>
#include <C_CkMessageSetW.h>
#include <C_CkEmailW.h>
#include <C_CkCertW.h>

void ChilkatSample(void)
    {
    BOOL success;
    HCkImapW imap;
    BOOL fetchUids;
    HCkMessageSetW messageSet;
    HCkEmailW email;
    HCkCertW cert;
    int i;
    const wchar_t *uid;

    success = FALSE;

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

    imap = CkImapW_Create();

    // Connect to an IMAP server.
    // Use TLS
    CkImapW_putSsl(imap,TRUE);
    CkImapW_putPort(imap,993);
    success = CkImapW_Connect(imap,L"imap.example.com");
    if (success == FALSE) {
        wprintf(L"%s\n",CkImapW_lastErrorText(imap));
        CkImapW_Dispose(imap);
        return;
    }

    success = CkImapW_Login(imap,L"myLogin",L"myPassword");
    if (success == FALSE) {
        wprintf(L"%s\n",CkImapW_lastErrorText(imap));
        CkImapW_Dispose(imap);
        return;
    }

    // Select an IMAP mailbox
    success = CkImapW_SelectMailbox(imap,L"Inbox");
    if (success == FALSE) {
        wprintf(L"%s\n",CkImapW_lastErrorText(imap));
        CkImapW_Dispose(imap);
        return;
    }

    // We can choose to fetch UIDs or sequence numbers.
    fetchUids = TRUE;

    // Get the message IDs of all the emails in the mailbox
    messageSet = CkMessageSetW_Create();
    success = CkImapW_QueryMbx(imap,L"ALL",fetchUids,messageSet);
    if (success == FALSE) {
        wprintf(L"%s\n",CkImapW_lastErrorText(imap));
        CkImapW_Dispose(imap);
        CkMessageSetW_Dispose(messageSet);
        return;
    }

    email = CkEmailW_Create();
    cert = CkCertW_Create();

    i = 0;
    while (i < CkMessageSetW_getCount(messageSet)) {

        uid = CkMessageSetW_GetId(messageSet,i);
        wprintf(L"uid: %s\n",uid);

        success = CkImapW_FetchEmail(imap,FALSE,uid,TRUE,email);
        if (success == FALSE) {
            wprintf(L"%s\n",CkImapW_lastErrorText(imap));
            CkImapW_Dispose(imap);
            CkMessageSetW_Dispose(messageSet);
            CkEmailW_Dispose(email);
            CkCertW_Dispose(cert);
            return;
        }

        // The security layers of signed and/or encrypted emails
        // are automatically "unwrapped" when loaded into
        // a Chilkat email object.
        // An application only needs to check to see if an email
        // was received signed or encrypted, and then examine
        // the success/failure.  For example:
        if (CkEmailW_getReceivedSigned(email) == TRUE) {

            wprintf(L"This email was signed.\n");

            // Check to see if the signatures were verified.
            if (CkEmailW_getSignaturesValid(email) == TRUE) {
                wprintf(L"Digital signature(s) verified.\n");
                wprintf(L"Signer: %s\n",CkEmailW_signedBy(email));

                // Get the certificate used for signing.
                success = CkEmailW_LastSignerCert(email,0,cert);

                if (success == FALSE) {
                    wprintf(L"Failed to get signing certificate object.\n");
                }
                else {
                    wprintf(L"Signing cert: %s\n",CkCertW_subjectCN(cert));
                }

            }
            else {
                wprintf(L"Digital signature verification failed.\n");
            }

        }

        i = i + 1;
    }

    // Disconnect from the IMAP server.
    success = CkImapW_Disconnect(imap);


    CkImapW_Dispose(imap);
    CkMessageSetW_Dispose(messageSet);
    CkEmailW_Dispose(email);
    CkCertW_Dispose(cert);

    }