(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 <CkMailMan.h>
#include <CkStringTable.h>
#include <CkEmail.h>
#include <CkCert.h>

void ChilkatSample(void)
    {
    bool success = false;

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

    CkMailMan mailman;

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

    // Set the POP3 login/password.
    mailman.put_PopUsername("myLogin");
    mailman.put_PopPassword("myPassword");

    CkStringTable stUidls;
    success = mailman.FetchUidls(stUidls);
    if (success == false) {
        std::cout << mailman.lastErrorText() << "\r\n";
        return;
    }

    CkEmail email;
    CkCert cert;

    int count = stUidls.get_Count();
    int i = 0;
    while (i < count) {
        // Download the full email.
        success = mailman.FetchByUidl(stUidls.stringAt(i),false,0,email);
        if (success == false) {
            std::cout << mailman.lastErrorText() << "\r\n";
            return;
        }

        std::cout << i << "\r\n";
        std::cout << "From: " << email.ck_from() << "\r\n";
        std::cout << "Subject: " << email.subject() << "\r\n";

        // 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 (email.get_ReceivedSigned() == true) {

            std::cout << "This email was signed." << "\r\n";

            // Check to see if the signatures were verified.
            if (email.get_SignaturesValid() == true) {
                std::cout << "Digital signature(s) verified." << "\r\n";
                std::cout << "Signer: " << email.signedBy() << "\r\n";

                success = email.LastSignerCert(0,cert);
                if (success == false) {
                    std::cout << email.lastErrorText() << "\r\n";
                    return;
                }

                std::cout << "Signing cert: " << cert.subjectCN() << "\r\n";
            }

        }
        else {
            std::cout << "Digital signature verification failed." << "\r\n";
        }

        i = i + 1;
    }

    mailman.Pop3EndSession();
    }