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

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

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_CkImap.h>
#include <C_CkMessageSet.h>
#include <C_CkEmail.h>
#include <C_CkCert.h>

void ChilkatSample(void)
    {
    HCkImap imap;
    BOOL success;
    BOOL fetchUids;
    HCkMessageSet messageSet;
    int i;
    const char *uid;
    HCkEmail email;
    HCkCert cert;

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

    imap = CkImap_Create();

    // Connect to an IMAP server.
    // Use TLS
    CkImap_putSsl(imap,TRUE);
    CkImap_putPort(imap,993);
    success = CkImap_Connect(imap,"imap.someMailServer.com");
    if (success != TRUE) {
        printf("%s\n",CkImap_lastErrorText(imap));
        CkImap_Dispose(imap);
        return;
    }

    success = CkImap_Login(imap,"myLogin","myPassword");
    if (success != TRUE) {
        printf("%s\n",CkImap_lastErrorText(imap));
        CkImap_Dispose(imap);
        return;
    }

    // Select an IMAP mailbox
    success = CkImap_SelectMailbox(imap,"Inbox");
    if (success != TRUE) {
        printf("%s\n",CkImap_lastErrorText(imap));
        CkImap_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 = CkImap_Search(imap,"ALL",fetchUids);
    if (CkImap_getLastMethodSuccess(imap) != TRUE) {
        printf("%s\n",CkImap_lastErrorText(imap));
        CkImap_Dispose(imap);
        return;
    }

    // Scan for emails with attachments, and save the attachments
    // to a sub-directory.
    i = 0;
    while (i < CkMessageSet_getCount(messageSet)) {

        uid = CkMessageSet_GetId(messageSet,i);
        printf("uid: %s\n",uid);

        email = CkImap_FetchSingle(imap,uid,TRUE);

        // 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 (CkEmail_getReceivedSigned(email) == TRUE) {

            printf("This email was signed.\n");

            // Check to see if the signatures were verified.
            if (CkEmail_getSignaturesValid(email) == TRUE) {
                printf("Digital signature(s) verified.\n");

                printf("Signer: %s\n",CkEmail_signedBy(email));

                // The certificate used for signing may be obtained
                // by calling email.GetSignedByCert.
                cert = CkEmail_GetSignedByCert(email);
                if (CkEmail_getLastMethodSuccess(email) != TRUE) {
                    printf("Failed to get signing certificate object.\n");
                }
                else {
                    printf("Signing cert: %s\n",CkCert_subjectCN(cert));
                    CkCert_Dispose(cert);
                }

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

        }

        CkEmail_Dispose(email);

        i = i + 1;
    }

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

    CkMessageSet_Dispose(messageSet);


    CkImap_Dispose(imap);

    }