(Lianja) 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 Lianja Extension Download Chilkat Lianja Extension

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

loImap = createobject("CkImap")

// Connect to an IMAP server.
// Use TLS
loImap.Ssl = .T.
loImap.Port = 993
llSuccess = loImap.Connect("imap.someMailServer.com")
if (llSuccess <> .T.) then
    ? loImap.LastErrorText
    release loImap
    return
endif

llSuccess = loImap.Login("myLogin","myPassword")
if (llSuccess <> .T.) then
    ? loImap.LastErrorText
    release loImap
    return
endif

// Select an IMAP mailbox
llSuccess = loImap.SelectMailbox("Inbox")
if (llSuccess <> .T.) then
    ? loImap.LastErrorText
    release loImap
    return
endif

// Download the 1st email (as MIME) in the Inbox by sequence number.
loSbMime = createobject("CkStringBuilder")
llSuccess = loImap.FetchSingleAsMimeSb(1,.F.,loSbMime)
if (llSuccess <> .T.) then
    ? loImap.LastErrorText
    release loImap
    release loSbMime
    return
endif

// Load it into a MIME object and check to see if it is signed
loMime = createobject("CkMime")
loMime.LoadMimeSb(loSbMime)
llAlreadySavedParts = .F.
if (loMime.ContainsSignedParts() = .T.) then

    // This will save the .p7s and other parts...
    loSa = loMime.ExtractPartsToFiles("qa_output")
    if (loMime.LastMethodSuccess = .T.) then
        lnNumFiles = loSa.Count
        i = 0
        do while i < lnNumFiles
            ? "Created: " + loSa.GetString(i)
            i = i + 1
        enddo
        release loSa
        llAlreadySavedParts = .T.
    endif

endif

// Load the MIME into an Email object.  This unwraps the security layers and verifies signatures.
loEmail = createobject("CkEmail")
loEmail.SetFromMimeSb(loSbMime)

if (loEmail.ReceivedSigned = .T.) then

    ? "This email was signed."

    // Check to see if the signatures were verified.
    if (loEmail.SignaturesValid = .T.) then
        ? "Digital signature(s) verified."

        ? "Signer: " + loEmail.SignedBy

        // The certificate used for signing may be obtained
        // by calling email.GetSignedByCert.
        loCert = loEmail.GetSignedByCert()
        if (loEmail.LastMethodSuccess <> .T.) then
            ? "Failed to get signing certificate object."
        else
            ? "Signing cert: " + loCert.SubjectCN
            release loCert
        endif

    endif

else
    ? "Digital signature verification failed."
endif

if (llAlreadySavedParts <> .T.) then
    loEmail.SaveAllAttachments("qa_output")
endif



release loImap
release loSbMime
release loMime
release loEmail