Java Requires Chilkat v11.0.0+

IMAP Download and Verify Signed MIME

See more IMAP Examples

Downloads the original MIME of a digitally signed email and saves the .p7s signature along with other MIME parts. It then imports the email into a Chilkat email object to unwrap the S/MIME and verify the signature, and subsequently saves the attachments if they haven't been saved already. Chilkat2 Java

import com.chilkatsoft.chilkat2.Cert;
import com.chilkatsoft.chilkat2.ChilkatException;
import com.chilkatsoft.chilkat2.Email;
import com.chilkatsoft.chilkat2.Imap;
import com.chilkatsoft.chilkat2.Mime;
import com.chilkatsoft.chilkat2.StringBuilder;
import com.chilkatsoft.chilkat2.StringTable;

public class ChilkatExample {

    public static void main(String[] args) {
        boolean success = false;

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

        Imap imap = new Imap();

        // Connect to an IMAP server.
        // Use TLS
        imap.setSsl(true);
        imap.setPort(993);
        try {
            imap.connect("imap.example.com");

            imap.login("myLogin", "myPassword");

            // Select an IMAP mailbox
            imap.selectMailbox("Inbox");
        } catch (ChilkatException e) {
            System.out.println(e.getLastErrorText());
            return;
        }

        // Download the 1st email (as MIME) in the Inbox by sequence number.
        StringBuilder sbMime = new StringBuilder();
        try {
            imap.fetchSingleAsMimeSb(1, false, sbMime);
        } catch (ChilkatException e) {
            System.out.println(e.getLastErrorText());
            return;
        }

        // Load it into a MIME object and check to see if it is signed
        Mime mime = new Mime();
        mime.loadMimeSb(sbMime);
        boolean alreadySavedParts = false;
        if (mime.containsSignedParts()) {
            // This will save the .p7s and other parts...
            StringTable st = new StringTable();
            try {
                mime.partsToFiles("c:/temp/qa_output", st);
                success = true;
            } catch (ChilkatException e) {
                success = false;
            }
            if (success) {
                int numFiles = st.getCount();
                int i = 0;
                while (i < numFiles) {
                    System.out.println("Created: " + st.stringAt(i));
                    i = i + 1;
                }

                alreadySavedParts = true;
            }
        }

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

        if (email.getReceivedSigned()) {
            System.out.println("This email was signed.");

            // Check to see if the signatures were verified.
            if (email.getSignaturesValid()) {
                System.out.println("Digital signature(s) verified.");
                System.out.println("Signer: " + email.getSignedBy());

                // The certificate used for signing may be obtained
                // by calling email.LastSignerCert.  Index 0 is the first signer.
                Cert cert = new Cert();
                try {
                    email.lastSignerCert(0, cert);
                    System.out.println("Signing cert: " + cert.getSubjectCN());
                } catch (ChilkatException e) {
                    System.out.println("Failed to get signing certificate object.");
                }
            } else {
                System.out.println("Digital signature verification failed.");
            }
        } else {
            System.out.println("This email was not signed.");
        }

        if (!alreadySavedParts) {
            email.saveAllAttachments("c:/temp/qa_output");
        }
    }
}