(Unicode C) POP3 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_CkMailManW.h>
#include <C_CkStringTableW.h>
#include <C_CkEmailW.h>
#include <C_CkCertW.h>

void ChilkatSample(void)
    {
    BOOL success;
    HCkMailManW mailman;
    HCkStringTableW stUidls;
    HCkEmailW email;
    HCkCertW cert;
    int count;
    int i;

    success = FALSE;

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

    mailman = CkMailManW_Create();

    // Set the POP3 server's hostname
    CkMailManW_putMailHost(mailman,L"pop.example.com");

    // Set the POP3 login/password.
    CkMailManW_putPopUsername(mailman,L"myLogin");
    CkMailManW_putPopPassword(mailman,L"myPassword");

    stUidls = CkStringTableW_Create();
    success = CkMailManW_FetchUidls(mailman,stUidls);
    if (success == FALSE) {
        wprintf(L"%s\n",CkMailManW_lastErrorText(mailman));
        CkMailManW_Dispose(mailman);
        CkStringTableW_Dispose(stUidls);
        return;
    }

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

    count = CkStringTableW_getCount(stUidls);
    i = 0;
    while (i < count) {
        // Download the full email.
        success = CkMailManW_FetchByUidl(mailman,CkStringTableW_stringAt(stUidls,i),FALSE,0,email);
        if (success == FALSE) {
            wprintf(L"%s\n",CkMailManW_lastErrorText(mailman));
            CkMailManW_Dispose(mailman);
            CkStringTableW_Dispose(stUidls);
            CkEmailW_Dispose(email);
            CkCertW_Dispose(cert);
            return;
        }

        wprintf(L"%d\n",i);
        wprintf(L"From: %s\n",CkEmailW_ck_from(email));
        wprintf(L"Subject: %s\n",CkEmailW_subject(email));

        // 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));

                success = CkEmailW_LastSignerCert(email,0,cert);
                if (success == FALSE) {
                    wprintf(L"%s\n",CkEmailW_lastErrorText(email));
                    CkMailManW_Dispose(mailman);
                    CkStringTableW_Dispose(stUidls);
                    CkEmailW_Dispose(email);
                    CkCertW_Dispose(cert);
                    return;
                }

                wprintf(L"Signing cert: %s\n",CkCertW_subjectCN(cert));
            }

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

        i = i + 1;
    }

    CkMailManW_Pop3EndSession(mailman);


    CkMailManW_Dispose(mailman);
    CkStringTableW_Dispose(stUidls);
    CkEmailW_Dispose(email);
    CkCertW_Dispose(cert);

    }