(Unicode C) IMAP Download and Verify Signed MIME

Downloads the unmodified MIME of a digitally signed email, saves the .p7s signature (and other MIME parts), then loads the email into a Chilkat email object (which unwraps the S/MIME and verifies the signature) and then saves attachments (if the MIME parts were not already saved).

Chilkat C/C++ Library Downloads
MS Visual C/C++ Linux/CentOS C/C++ Alpine Linux C/C++ MAC OS X C/C++	armhf/aarch64 C/C++ C++ Builder iOS C/C++ Android C/C++	Solaris C/C++ MinGW C/C++

#include <C_CkImapW.h>
#include <C_CkStringBuilderW.h>
#include <C_CkMimeW.h>
#include <C_CkStringArrayW.h>
#include <C_CkEmailW.h>
#include <C_CkCertW.h>

void ChilkatSample(void)
    {
    HCkImapW imap;
    BOOL success;
    HCkStringBuilderW sbMime;
    HCkMimeW mime;
    BOOL alreadySavedParts;
    HCkStringArrayW sa;
    int numFiles;
    int i;
    HCkEmailW email;
    HCkCertW cert;

    // 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.someMailServer.com");
    if (success != TRUE) {
        wprintf(L"%s\n",CkImapW_lastErrorText(imap));
        CkImapW_Dispose(imap);
        return;
    }

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

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

    // Download the 1st email (as MIME) in the Inbox by sequence number.
    sbMime = CkStringBuilderW_Create();
    success = CkImapW_FetchSingleAsMimeSb(imap,1,FALSE,sbMime);
    if (success != TRUE) {
        wprintf(L"%s\n",CkImapW_lastErrorText(imap));
        CkImapW_Dispose(imap);
        CkStringBuilderW_Dispose(sbMime);
        return;
    }

    // Load it into a MIME object and check to see if it is signed
    mime = CkMimeW_Create();
    CkMimeW_LoadMimeSb(mime,sbMime);
    alreadySavedParts = FALSE;
    if (CkMimeW_ContainsSignedParts(mime) == TRUE) {

        // This will save the .p7s and other parts...
        sa = CkMimeW_ExtractPartsToFiles(mime,L"qa_output");
        if (CkMimeW_getLastMethodSuccess(mime) == TRUE) {
            numFiles = CkStringArrayW_getCount(sa);
            i = 0;
            while (i < numFiles) {
                wprintf(L"Created: %s\n",CkStringArrayW_getString(sa,i));
                i = i + 1;
            }

            CkStringArrayW_Dispose(sa);
            alreadySavedParts = TRUE;
        }

    }

    // Load the MIME into an Email object.  This unwraps the security layers and verifies signatures.
    email = CkEmailW_Create();
    CkEmailW_SetFromMimeSb(email,sbMime);

    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));

            // The certificate used for signing may be obtained
            // by calling email.GetSignedByCert.
            cert = CkEmailW_GetSignedByCert(email);
            if (CkEmailW_getLastMethodSuccess(email) != TRUE) {
                wprintf(L"Failed to get signing certificate object.\n");
            }
            else {
                wprintf(L"Signing cert: %s\n",CkCertW_subjectCN(cert));
                CkCertW_Dispose(cert);
            }

        }

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

    if (alreadySavedParts != TRUE) {
        CkEmailW_SaveAllAttachments(email,L"qa_output");
    }



    CkImapW_Dispose(imap);
    CkStringBuilderW_Dispose(sbMime);
    CkMimeW_Dispose(mime);
    CkEmailW_Dispose(email);

    }