I need to get an attachment out of an email received through a pop or imap adapter and process it further. The problem is that what I get out of that mail adapter is only the message of the mail(no title, no attachment).
Attachment should be possible acc. to this: https://uacp2.hana.ondemand.com/doc/368c481cd6954bdfa5d0435479fd4eaf/Cloud/en-US/08af047a0c0145ab8742b946cff7bcd7.html
As you can read: To access the mail attributes, i. e. Subject, From or To, you have to set them manually as Allowed Headers in the Runtime Configuration tab page. This will add them to a Whitelist.
The headers must be set in a Content Modifier as message header. I'll guess before receiving or sending the mail.
e.g. Accept | Constant | Type java.lang.String | Text/Plain
other values possible instead of Text/Plain:
Text/CSV
Text/HTML
Application/XML
Application/JSON
Application/Octet-Stream
Related
Does message rfc822 allow a new line in between two headers?
After Content-Disposition I got a newline.
Attaching Image
The Received header (and all of the headers that follow it) are not part of the MIME part headers - they are the content of the MIME part.
This attachment has a MIME-type of message/rfc822 which is an email message. When you parse the content of the MIME part (which starts with the Received header), what you end up with is another message object.
I am looking to encrypt certain mail headers (Subject and Reply-To) which are being sent in an encrypted mail.
I am taking an entire MIME (Headers included) and successfully encrypting it.
I can send this S/MIME encrypted mail to my mail client (Thunderbird) successfully. It will be successfully decrypted and verified as signed.
However, any headers that are sent in the inner encrypted MIME are not being used by my mail client.
According to RFC-5751 I should be wrapping my mail in a message/rfc822 message but I am at a loss at how to achieve this.
Below are examples of my messages that I am creating.
My first question is, is the last MIME that I am creating the message/rfc822 correctly structured?
Is this possibly an issue with the mail client?
Can I event encrypt the Reply-To Header?
If I could get an example of a mesage/rfc822 encapsulated message that would be really helpful.
Mail to be encrypted
This will successfully result in a received mail that is signed and the Subject / Reply-To headers are interpreted correctly by the mail client.
Content-Type: multipart/signed; protocol="application/pkcs7-signature";
micalg=sha256; boundary="--_NmP-d017e0e3556f7bbc-Part_1"
From: sender#domain.com
Sender: senderdomain.com
To: recipient#domain.com
Reply-To: keepsecret#domain.com
Subject: A Secret Subject
Message-ID: <400b1383-362b-eed7-0719-6b2a2e231143>
Date: Mon, 24 Feb 2020 15:59:19 +0000
MIME-Version: 1.0
----_NmP-d017e0e3556f7bbc-Part_1
Content-Type: text/plain
Content-Transfer-Encoding: 7bit
My Message that will be encrypted
----_NmP-d017e0e3556f7bbc-Part_1
Content-Type: application/pkcs7-signature; name=smime.p7s
Content-Transfer-Encoding: base64
Content-Disposition: attachment; filename=smime.p7s
MIIOCAYJKoZIhvcNAQcCoIIN+TCCDfUCAQExDzANBglghkgBZQMEAgEFADALBgkqhkiG9w0BBwGg
gguTMIIFCDCCA/CgAwIBAgIQVz2HAGYJcTJNsPiWLx1f/TANBgkqhkiG9w0BAQsFADCBjTELMAkG
.
.
.
17p13e02JxfyCqltdb6lkOdpRZ6ZlHHuQZyBCuRtJhRN83gvcJ4d7WCxKI349NEa2/tOb8ziFGat
gzvgu+o=
----_NmP-d017e0e3556f7bbc-Part_1--
My Encrypted Mail
This encrypted mail will be received and successfully decrypted and verified (signature verified) by my mail client. Reply-To and Subject are still working as expected as they are still visible. Note: all the headers from the unencrypted mail are all still present inside the encrypted body of this message.
Sender: sender#domain.com
From: sender#domain.com
To: recipient#domain.com
Subject: A Secret Subject
Reply-To: keepsecret#domain.com
Message-ID: <400b1383-362b-eed7-0719-6b2a2e231143>
Content-Transfer-Encoding: base64
Content-Disposition: attachment; filename=smime.p7m
Content-Type: application/pkcs7-mime; smime-type=enveloped-data;
name=smime.p7m
Date: Mon, 24 Feb 2020 16:03:38 +0000
MIME-Version: 1.0
MIIYbwYJKoZIhvcNAQcDoIIYYDCCGFwCAQAxggG/MIIBuwIBADCBojCBjTELMAkG
.
.
.
O+EPVCh1fGDFwiFpDtY/z1Lv8g==
My Encapsulated message/rfc822
This message will be decrypted correctly but my client does not recognise that it was an encrypted message or verify that it was signed (Not worried about that so much). The decrypted mail is interpreted as forwarded and attached as an .eml file. However, no Subject or Reply-To headers found (they are in the encrypted mail). If I add dummy values as recommended by the RFC, those dummy values will be used by my mail client, not the encrypted ones.
Content-Type: message/rfc822; forwarded=false; boundary="--_NmP-07c15c542cedfe74-Part_1"
From: sender#domain.com
Sender: sender#domain.com
To: recipient#domain.com
Date: Mon, 24 Feb 2020 15:28:07 +0000
Message-ID: <400b1383-362b-eed7-0719-6b2a2e231143>
MIME-Version: 1.0
----_NmP-07c15c542cedfe74-Part_1
Content-Transfer-Encoding: base64
Content-Disposition: attachment; filename=smime.p7m
Content-Type: application/pkcs7-mime; smime-type=enveloped-data;
name=smime.p7m
MIIYbwYJKoZIhvcNAQcDoIIYYDCCGFwCAQAxggG/MIIBuwIBADCBojCBjTELMAkG
.
.
.
fYU1LuhSBEyymSVRzwWr2T3lrhUe5BZBoY996epZtOPdIYrz2jqUglii1+AUBpUP
UUnpr8+cHTMk/50LHdy3MqMeYA==
----_NmP-07c15c542cedfe74-Part_1
Edit: add excerpt from RFC
In RFC-8551 it states the following
In order to protect outer, non-content-related message header fields (for instance, the "Subject", "To", "From", and "Cc" fields), the
sending client MAY wrap a full MIME message in a message/rfc822
wrapper in order to apply S/MIME security services to these header
fields. It is up to the receiving client to decide how to present
this "inner" header along with the unprotected "outer" header. Given
the security difference between headers, it is RECOMMENDED that the
receiving client provide a distinction between header fields,
depending on where they are located.
When an S/MIME message is received, if the top-level protected MIME
entity has a Content-Type of message/rfc822, it can be assumed that
the intent was to provide header protection. This entity SHOULD be
presented as the top-level message, taking into account
header-merging issues as previously discussed.
RFC 822 provides a generalized description of how message headers of an email are composed and should be treated by systems they are transmitted through. RFC 5751 S/MIME 3.2 (btw, obsoleted by it successor RFC 8551 S/MIME 4.0) describes details how to use that standard to create encrypted emails.
So your approach to encrypt an email as described under My Encrypted Mail is valid and correct.
However, your approach as described under My Encapsulated message/rfc822 is not quite correct. You have obviously misinterpreted the RFC with regard to how to apply the rfc822 wrapper. The wrapper needs to be around your message before it gets encrypted, so it's going to be inside the encrypted part.
In your example, the unencrypted message (a slightly modified version Mail to be encrypted) would have to look like this:
MIME-Version: 1.0
Content-type: message/rfc822
From: sender#domain.com
Sender: senderdomain.com
To: recipient#domain.com
Reply-To: keepsecret#domain.com
Subject: A Secret Subject
Message-ID: <400b1383-362b-eed7-0719-6b2a2e231143>
Date: Mon, 24 Feb 2020 15:59:19 +0000
MIME-Version: 1.0
Content-Type: multipart/signed; protocol="application/pkcs7-signature"; micalg=sha256; boundary="--_NmP-d017e0e3556f7bbc-Part_1"
----_NmP-d017e0e3556f7bbc-Part_1
Content-Type: text/plain
Content-Transfer-Encoding: 7bit
My Message that will be encrypted
[...]
So you basically add the message/rfc822 to the message before it gets encrypted.
I have been able to verify this approach and tested the resulting message in two receiving mail clients with different results. With the macOS Mail application, the encrypted subject was not used to replace the unprotected "outer" subject, but at least, it was displayed prominently below the original headers. This is compliant with the RFC which is not very specific about the presentation:
It is up to the receiving client to decide how to present this "inner" header along with the unprotected "outer" header. Given the security difference between headers, it is RECOMMENDED that the receiving client provide a distinction between header fields, depending on where they are located.
An encrypted Reply-To header is displayed similarly, but it's email address is not honored when replying to that email.
Client Support
The support for encrypted headers in clients is somewhere between weak and non-existent. The results of some tests:
No client supports replacing the "outer" headers by the "inner" encrypted ones
Apple Mail (macOS) displays the inner headers prominently within the message
Thunderbird displays the encrypted part including its headers as a forwarded message
Outlook does not display the encrypted part, but instead confusingly displays just an empty message with an attachment (which is the encrypted message)
Alternative approaches
There is a seemingly promising approach proposed in this draft for Protected Headers for Cryptographic E-mail (work in progress). The idea is to include the protected headers as a separate part in a multipart message. This part will be rendered inline by agnostic clients, while at the same time, it can be properly processed by supporting clients.
I am using mimedefang filtering tool. In the configuration, I strip out all the attachments and forward it to another address. For particular sender, I can see milter changes the header Content-Type from application/pdf and multipart-mixed. In the received email on outlook, when I open the pdf using text editor (it contains content like ("This is a multi-part message in MIME format..." followed by some random numbers "------------=_1525668389-64274-8--").
Can anyone guess why this might be happening?
Multi-part messages (like those with attachments) have their parts divided by a boundary. This boundary is between 1 and 70 characters and must not appear anywhere in the anywhere within the encapsulated parts of the message (between boundaries).
MIME-Version: 1.0
Content-Type: multipart/mixed; boundary=gc0p4Jq0M2Yt08jU534c0p
This is a message with multiple parts in MIME format.
--gc0p4Jq0M2Yt08jU534c0p
Content-Type: text/html; charset=UTF-8
<html><head></head><body>This is the HTML body of the message.</body></html>
--gc0p4Jq0M2Yt08jU534c0p
Content-Type: text/plain
This is the body of the message.
--gc0p4Jq0M2Yt08jU534c0p
Content-Type: application/octet-stream
Content-Transfer-Encoding: base64
PGh0bWw+CiAgPGhlYWQ+CiAgPC9oZWFkPgogIDxib2R5PgogICAgPHA+VGhpcyBpcyB0aGUg
Ym9keSBvZiB0aGUgbWVzc2FnZS48L3A+CiAgPC9ib2R5Pgo8L2h0bWw+Cg==
--gc0p4Jq0M2Yt08jU534c0p--
I suspect that somewhere between mimedefang and your milter configuration, the boundaries are getting mangled or included into the attachment can causing them to be corrupted.
Requirement: To send VB file of records length 100 as attachment using TCPSMTP utility with proper message in body without using IEBGENER utility.
I am trying to send email attachment file VB dataset as attachment. Its working either message in attachment or attachment file in body. But both simultaneously not working.
My JCL is:
//IRTCPN15 EXEC PROC=TCPSMTP
//SMTPIN DD DSN=EMAIL.CODE,
// DISP=SHR
// DD DSN=FILE.TOBE.SENTAS.ATTACH.MENT,DISP=SHR
Here, I have used both datasets EMAIL.CODE and FILE.TOBE.SENTAS.ATTACH.MENT of same specification VB 100 record length. I have also tried using boundary demiliter, but still its not working both together.
Dataset EMAIL.CODE contains:
HELO *******
MAIL FROM:<*******>
RCPT TO: <********>;
DATA
FROM: <******>
TO: <*******>;
SUBJECT: subject data
MIME-VERSION: 1.0
CONTENT-TYPE: TEXT/PLAIN
---Mail Body---
CONTENT DISPOSITION: ATTACHMENT; FILENAME=FILE.TXT
Please suggest me how to send this attachment with body. I have used asterisk due to security reasons. Please feel free to ask if any more information is needed.
In the EMAIL.CODE dataset, you're specifying that content-type of your message is text/plain. However, text/plain on its own (which is the default content type anyway) is always going to appear inline.
In order for the text in the message to be seen as an attachment, you need a Content-Disposition header that specifies attachment.
I can see in your question that you have a CONTENT DISPOSITION line, but it's labeled as being part of the message body. In addition to the fact that it needs to be a header, not a part of the body, it also needs to be hyphenated. So you should have CONTENT-DISPOSITION, not CONTENT DISPOSITION.
However, what all of this gets you is a message containing nothing but the attachment, and your question specifies that you want both a message body and an attachment. In order to do that, your Content-type at the top level needs to be multipart/mixed, and the body of the message needs to contain two MIME parts, one specified simply as being text/plain, and the other also text/plain, but with Content-Disposition: attachment.
This example shows the data for a MIME message containing both a text/plain body and a text/plain attachment.
FROM: <sender#example.com>
TO: <receiver#example.com>
Subject: TESTING message with body and attachment.
Mime-Version: 1.0
Content-type: multipart/mixed; boundary=MIME_BOUNDARY
This is the non-MIME body of a multipart message in MIME format.
Unless you are using a genuinely ancient email client or viewing
the raw source of a message, you should never see this paragraph.
--MIME_BOUNDARY
Content-type: text/plain
This is the inline text section of a multipart message
in MIME format. This is what will appear as the body
of your email when using any normal email client.
--MIME_BOUNDARY
Content-type: text/plain
Content-Disposition: attachment; filename=example.txt
This is the plain-text attachment.
--MIME_BOUNDARY--
.
I am working on a script that will handle email attachments. I see that, most of the time, both content-type and content-disposition headers have the filename, but I have seen cases where only one had proper encoding or valid mime header.
Is there a preferred header to use to extract the file name? If so, which one?
Quoting wikipedia http://en.wikipedia.org/wiki/MIME:
"Many mail user agents also send messages with the file name in the name parameter of the content-type header instead of the filename parameter of the content-disposition header. This practice is discouraged."
So it seems content-disposition is preferred. However as I am using JavaMail, current JavaMail API seems to have only a String getDisposition() method: http://javamail.kenai.com/nonav/javadocs/javax/mail/Part.html#getDisposition(). So you might need to work with the header directly if you are using JavaMail.