Valid S/MIME Header?

Gateway
1

Hello,

today we got a mail to a mostly idle domain which has not set "remove
certificates" so signed e-mail would pass by. The e-mail in question
was encrypted and was decrypted as it should from my point of view,
but the messaging system where the mail was finally viewed does only
display the smime.p7m. The header was
This is a multipart message in MIME format

--27817437
Content-Type: application/x-pkcs7-mime; name="=?iso-8859-1?Q?smime.p7m?="
Content-Transfer-Encoding: Base64
Content-Disposition: attachment; filename="=?iso-8859-1?Q?smime.p7m?="

which lacks the "smime-type", no? Thunderbird display the mail and
content fine, but does not show any "Signed" signal for the mail at
all...

Regards

Andreas

2

Since the content type is application/x-pkcs7-mime and name is smime.p7m
it probably is a S/MIME opaque signed attachment. What is strange is
that an smime.p7m is normally never used with a multipart message since
this is not a valid S/MIME message. It looks like the message was opaque
signed and then the message was changed (disclaimer service?) and then
encrypted.

Can you send me the message of list so I can investigate the message?

Kind regards,

Martijn Brinkers

ยทยทยท

On 07/21/2014 06:41 PM, lst_hoe02(a)kwsoft.de wrote:

today we got a mail to a mostly idle domain which has not set "remove
certificates" so signed e-mail would pass by. The e-mail in question was
encrypted and was decrypted as it should from my point of view, but the
messaging system where the mail was finally viewed does only display the
smime.p7m. The header was
This is a multipart message in MIME format

--27817437
Content-Type: application/x-pkcs7-mime; name="=?iso-8859-1?Q?smime.p7m?="
Content-Transfer-Encoding: Base64
Content-Disposition: attachment; filename="=?iso-8859-1?Q?smime.p7m?="

which lacks the "smime-type", no? Thunderbird display the mail and
content fine, but does not show any "Signed" signal for the mail at all...

--
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