7451 S/MIME Broken

Problem reported by Robert Simpson - 5/28/2020 at 9:10 AM

Resolved

Testing out MAPI with a digital signature today ... sent an e-mail via MAPI to my work account, and it appears botched on my work account (Office 365)

I digitally signed the e-mail and sent via SM Beta over MAPI. The received e-mail I got had a blank body, and a message that "Outlook blocked an unsafe atttachment file.tmp"

It looks OK in my Sent Items folder inside Outlook, but it's definitely NOT OK on the SM Web Interface Sent Items folder.

6 Replies

Reply to Thread

Robert Simpson Replied

5/28/2020 at 9:25 AM

This is what it looks like in Outlook's Sent Items folder:

The above e-mail was sent with "Add a digital signature to this message" checked, but not the "Send this message as clear text signed" checked.

And this is what it looks like in the SM web interface Sent Items folder (raw data)

From: "Robert Simpson" <robert@domain.com>
To: <robert.simpson@workdomain.com>
Subject: Test
Date: Thu, 28 May 2020 09:06:50 -0700
Reply-To: robert@domain.com
Message-ID: <03dcdc0e83a840579eb7c7cc04010ac8@>
MIME-Version: 1.0
Content-Type: multipart/mixed; boundary=fcc03c411c224a95a85703af64480075

This is a multipart message in MIME format.

--fcc03c411c224a95a85703af64480075
Content-Type: text/plain;
	charset="iso-8859-1"
Content-Transfer-Encoding: quoted-printable



--fcc03c411c224a95a85703af64480075
Content-Type: application/pkcs7-mime
Content-Transfer-Encoding: base64
Content-Disposition: attachment;
	filename="file.tmp"

BASE64STRIPPEDOUT

--fcc03c411c224a95a85703af64480075--

There's quite a lot wrong with this. If I check the "Send this message as clear text signed" as well, I get a different output, but it's still wrong, and Exchange still can't understand it.

Robert Simpson Replied

5/28/2020 at 9:42 AM

Sending via EAS works fine. Raw data in SM Sent Items looks like this:

To: "Robert Simpson" <robert.simpson@workdomain.com>
Subject: Activesync signed test
Date: Thu, 28 May 2020 09:40:57 -0700
Message-ID: <01ef01d6350e$c36133f0$4a239bd0$@domain.com>
MIME-Version: 1.0
Content-Type: application/pkcs7-mime;
	smime-type=signed-data;
	name="smime.p7m"
Content-Transfer-Encoding: base64
Content-Disposition: attachment;
	filename="smime.p7m"
X-Mailer: Microsoft Outlook 16.0
Thread-Index: AdY1DnWKzI5aeUdPSNSvJQ4r3eR3uw==
Content-Language: en-us
From: "Robert Simpson" <robert@domain.com>

BASE64STRIPPED