(Ruby) IMAP Download and 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.

Chilkat Ruby Downloads install from rubygems.org gem install chilkat or download... Ruby Library for Windows, MacOS, Linux, Alpine Linux

require 'chilkat'

success = false

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

imap = Chilkat::CkImap.new()

# Connect to an IMAP server.
# Use TLS
imap.put_Ssl(true)
imap.put_Port(993)
success = imap.Connect("imap.example.com")
if (success == false)
    print imap.lastErrorText() + "\n";
    exit
end

success = imap.Login("myLogin","myPassword")
if (success == false)
    print imap.lastErrorText() + "\n";
    exit
end

# Select an IMAP mailbox
success = imap.SelectMailbox("Inbox")
if (success == false)
    print imap.lastErrorText() + "\n";
    exit
end

# We can choose to fetch UIDs or sequence numbers.
fetchUids = true

# Get the message IDs of all the emails in the mailbox
messageSet = Chilkat::CkMessageSet.new()
success = imap.QueryMbx("ALL",fetchUids,messageSet)
if (success == false)
    print imap.lastErrorText() + "\n";
    exit
end

email = Chilkat::CkEmail.new()
cert = Chilkat::CkCert.new()

i = 0
while i < messageSet.get_Count()

    uid = messageSet.GetId(i)
    print "uid: " + uid + "\n";

    success = imap.FetchEmail(false,uid,true,email)
    if (success == false)
        print imap.lastErrorText() + "\n";
        exit
    end

    # 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)

        print "This email was signed." + "\n";

        # Check to see if the signatures were verified.
        if (email.get_SignaturesValid() == true)
            print "Digital signature(s) verified." + "\n";
            print "Signer: " + email.signedBy() + "\n";

            # Get the certificate used for signing.
            success = email.LastSignerCert(0,cert)

            if (success == false)
                print "Failed to get signing certificate object." + "\n";
            else
                print "Signing cert: " + cert.subjectCN() + "\n";
            end

        else
            print "Digital signature verification failed." + "\n";
        end

    end

    i = i + 1
end

# Disconnect from the IMAP server.
success = imap.Disconnect()