Footer Stamping Digitally Signed Messages

[Corey_ironport]

What happens to a message if I am stamping footers with dislaimer messages, but the outbound message is digitally signed?

[robertrenner]

good question *push*

from my point of view the disclaimer may be attached as attachment, right ?


at the moment i have the problem that digitally signed outgoing mails get the disclaimer (the HTML one) as the only body text. the normal message body is replaced by the html disclaimer.... at the moment i think it's when spcial characters are in the mail body but i can't reproduce it at the moment :( any ideas?

grz,
Rob

[japan_ironport]

Since the disclaimer goes after the message has been signed, its integrity is gone... So the signature will no longer be valid.
This is how it works...

I've heard about "enveloping" solutions but I don't really think it can work.

You will have to rely on the end-user to insert the disclaimer.

What you can do, (if you can't find a workaround to insert the disclaimer after the digital signature without problems) is use a content filter that looks for the disclaimer in the body. If it's not there, the message will go back to the sender with a message [NO DISCLAIMER] or something...

[robertrenner]

okay,

so i have to discuss this ... and may i have to edit the disclaimer filter to check for signed or encrpyted messages and have to exclude this ones from beeing "disclaimered" :)

thanks a lot for your fast reply :)

[rouben_ironport]

okay, 

so i have to discuss this ... and may i have to edit the disclaimer filter to check for signed or encrpyted messages and have to exclude this ones from beeing "disclaimered" :) 

thanks a lot for your fast reply :)

One way to do that would be to check for the presence of the following MIME types:

• application/pkcs7-mime
• multipart/signed
• multipart/encrypted
• application/pkcs7-signature
• application/octet-stream with file extensions of p7m, p7s, p7c or pgp
• application/pgp-encrypted
• application/pgp-signed

The above list is more than likely not at all exhaustive... :(