Helo,
is there any possibility to notify the receiver for a signd mail about a
successfully complete sign check? At the moment i can not find any adjustment
to do that. How does the user konw anything about the sign of a received
message?best regards
Matthias
I'm not sure I understand you question. What do you mean with "..to
notify the receiver for a signd mail about a successfully complete sign
check?"
Kind regards,
Martijn Brinkers
On 10/27/2011 08:29 AM, matthiasdort wrote:
is there any possibility to notify the receiver for a signd mail about a
successfully complete sign check? At the moment i can not find any adjustment
to do that. How does the user konw anything about the sign of a received
message?
--
Djigzo open source email encryption
Zitat von Martijn Brinkers <martijn(a)djigzo.com>:
On 10/27/2011 08:29 AM, matthiasdort wrote:
is there any possibility to notify the receiver for a signd mail about a
successfully complete sign check? At the moment i can not find any
adjustment
to do that. How does the user konw anything about the sign of a received
message?I'm not sure I understand you question. What do you mean with "..to
notify the receiver for a signd mail about a successfully complete sign
check?"Kind regards,
Martijn Brinkers
I guess something like a "[Signed]" tag in the subject to show the end
user (internal recipient) that the message was signed and could be
verified when hitting the Djigzo Gateway.
Regards
Andreas
Do Okt 27 2011 09:19:15 CEST von "lst_hoe02" <lst_hoe02(a)kwsoft.de>
Betreff: Re: Notify about a successfully complete for
signcheckZitat von Martijn Brinkers <martijn(a)djigzo.com>:
On 10/27/2011 08:29 AM, matthiasdort wrote:
is there any possibility to notify the receiver for a signd mail about a
successfully complete sign check? At the moment i can not find any
adjustment
to do that. How does the user konw anything about the sign of a received
message?I'm not sure I understand you question. What do you mean with "..to
notify the receiver for a signd mail about a successfully complete sign
check?"Kind regards,
Martijn Brinkers
I guess something like a "[Signed]" tag in the subject to show the end
user (internal recipient) that the message was signed and could be
verified when hitting the Djigzo Gateway.Regards
Andreas
Thank you Andreas, yes, this is exactly what i mean.
This is not (yet?) supported. The main question is where are you using
the tag for? The reason I'm asking is that a tag line can lead to a
false sense of security. For example suppose an external sender sends a
non-signed message that contains the tag [Signed] in the subject?
You might argue that all incoming email should be scanned for such a tag
and have the tag be removed. Ok, then what about [ signed ]? Again you
might argue that the scanning should work on a regular expression and
should skip all spaces. Ok, then I come up with the following example,
{Signed}, or just Signed, or Signd.
Just as long as your end-users just use the tag as an indication that
the message *might* be signed, this should not be a problem. The problem
starts when end-users *assume* the message is signed and trusted because
the subject contains some kind of tag.
The best way to detect whether a message is signed and is trusted is by
using an S/MIME capable email client. If however you are not using an
S/MIME capable email client or are stripping the S/MIME signatures this
won't help. The gateway will however add certain header fields which
indicate whether the email is signed and whether the signature was
trusted/valid etc. Appendix A of the "S/MIME setup guide" briefly
explains these headers. Since all X-Djigzo-* headers are removed from
any incoming email, those headers cannot be spoofed. The trouble however
with these headers is that it's hard for end-users to read and interpret.
To conclude, I'm not saying that adding some kind of keyword/tag to the
subject should never be done. But, you should be careful on what it
means for your end-users when the subject contains a certain keyword/tag.
What is currently missing is a mailet (a mailet is a small piece of
software that handles an email) that can add something to the current
subject of a message. I will add this to the todo list. If such a mailet
is available, you can add this functionality to the xml mail flow
specification and match when the email contains the keywords. This might
actually be done with Postfix as a workaround.
One last question, is there a reason you cannot use an S/MIME email
client to check the signatures?
Kind regards,
Martijn Brinkers
On 10/27/2011 09:25 AM, matthiasdort wrote:
I guess something like a "[Signed]" tag in the subject to show the end
user (internal recipient) that the message was signed and could be
verified when hitting the Djigzo Gateway.Thank you Andreas, yes, this is exactly what i mean.
--
Djigzo open source email encryption
Zitat von Martijn Brinkers <martijn(a)djigzo.com>:
I guess something like a "[Signed]" tag in the subject to show the end
user (internal recipient) that the message was signed and could be
verified when hitting the Djigzo Gateway.Thank you Andreas, yes, this is exactly what i mean.
This is not (yet?) supported. The main question is where are you using
the tag for? The reason I'm asking is that a tag line can lead to a
false sense of security. For example suppose an external sender sends a
non-signed message that contains the tag [Signed] in the subject?
You might argue that all incoming email should be scanned for such a tag
and have the tag be removed. Ok, then what about [ signed ]? Again you
might argue that the scanning should work on a regular expression and
should skip all spaces. Ok, then I come up with the following example,
{Signed}, or just Signed, or Signd.
Just as long as your end-users just use the tag as an indication that
the message *might* be signed, this should not be a problem. The problem
starts when end-users *assume* the message is signed and trusted because
the subject contains some kind of tag.The best way to detect whether a message is signed and is trusted is by
using an S/MIME capable email client. If however you are not using an
S/MIME capable email client or are stripping the S/MIME signatures this
won't help. The gateway will however add certain header fields which
indicate whether the email is signed and whether the signature was
trusted/valid etc. Appendix A of the "S/MIME setup guide" briefly
explains these headers. Since all X-Djigzo-* headers are removed from
any incoming email, those headers cannot be spoofed. The trouble however
with these headers is that it's hard for end-users to read and interpret.To conclude, I'm not saying that adding some kind of keyword/tag to the
subject should never be done. But, you should be careful on what it
means for your end-users when the subject contains a certain keyword/tag.What is currently missing is a mailet (a mailet is a small piece of
software that handles an email) that can add something to the current
subject of a message. I will add this to the todo list. If such a mailet
is available, you can add this functionality to the xml mail flow
specification and match when the email contains the keywords. This might
actually be done with Postfix as a workaround.
Actually most of the end users don't care or don't have a deep
understanding of the security implications anyway. It might be useful
to train the users that they can, to some extend rely on a Tag in the
subject to:
- be sure the sender is really the one claimed
- the message was not altered in transit
- they can send encrypted mail to that sender
This can be spoofed as you said by similar looking Tags, but try to
trick the users is at least more difficult then.
One last question, is there a reason you cannot use an S/MIME email
client to check the signatures?
There are two possibilities:
- We have for example an internal message system which is not S/MIME
aware and this might apply to other ticket or workflow based systems
as well
- The S/MIME handling should be limited to the gateway because the
internal certstores are not managed and might not have the CAs needed
or more than desired
Furthermore this would be easier to support within organisations using
many different mailclients with many different UIs showing signed
messages in many different ways.
But as you noticed it has also disadvantegs. The user should not learn
to blindly rely on a subject Tag. But in pratice most of them do not
see any difference between a subject Tag and a "signed" Icon in there
mailclient anyway 
If it is not too much work, i'll vote for it...
Regards
Andreas
On 10/27/2011 09:25 AM, matthiasdort wrote:
I have added a JIRA feature request
(https://jira.djigzo.com/browse/GATEWAY-36). I don't think it will be
included with 2.3.1 release since that has already been "feature
freez'd". It will be included after the 2.3.1 release.
Kind regards,
Martijn
On 10/27/2011 11:19 AM, lst_hoe02(a)kwsoft.de wrote:
> On 10/27/2011 09:25 AM, matthiasdort wrote:
>>>> I guess something like a "[Signed]" tag in the subject to show the end
>>>> user (internal recipient) that the message was signed and could be
>>>> verified when hitting the Djigzo Gateway.>>>
>>>
>>>
>>> Thank you Andreas, yes, this is exactly what i mean.>
> This is not (yet?) supported. The main question is where are you using
> the tag for? The reason I'm asking is that a tag line can lead to a
> false sense of security. For example suppose an external sender sends a
> non-signed message that contains the tag [Signed] in the subject?
> You might argue that all incoming email should be scanned for such a tag
> and have the tag be removed. Ok, then what about [ signed ]? Again you
> might argue that the scanning should work on a regular expression and
> should skip all spaces. Ok, then I come up with the following example,
> {Signed}, or just Signed, or Signd.
> Just as long as your end-users just use the tag as an indication that
> the message *might* be signed, this should not be a problem. The problem
> starts when end-users *assume* the message is signed and trusted because
> the subject contains some kind of tag.
>
> The best way to detect whether a message is signed and is trusted is by
> using an S/MIME capable email client. If however you are not using an
> S/MIME capable email client or are stripping the S/MIME signatures this
> won't help. The gateway will however add certain header fields which
> indicate whether the email is signed and whether the signature was
> trusted/valid etc. Appendix A of the "S/MIME setup guide" briefly
> explains these headers. Since all X-Djigzo-* headers are removed from
> any incoming email, those headers cannot be spoofed. The trouble however
> with these headers is that it's hard for end-users to read and interpret.
>
> To conclude, I'm not saying that adding some kind of keyword/tag to the
> subject should never be done. But, you should be careful on what it
> means for your end-users when the subject contains a certain keyword/tag.
>
> What is currently missing is a mailet (a mailet is a small piece of
> software that handles an email) that can add something to the current
> subject of a message. I will add this to the todo list. If such a mailet
> is available, you can add this functionality to the xml mail flow
> specification and match when the email contains the keywords. This might
> actually be done with Postfix as a workaround.Actually most of the end users don't care or don't have a deep
understanding of the security implications anyway. It might be useful
to train the users that they can, to some extend rely on a Tag in the
subject to:
- be sure the sender is really the one claimed
- the message was not altered in transit
- they can send encrypted mail to that senderThis can be spoofed as you said by similar looking Tags, but try to
trick the users is at least more difficult then.> One last question, is there a reason you cannot use an S/MIME email
> client to check the signatures?There are two possibilities:
- We have for example an internal message system which is not S/MIME
aware and this might apply to other ticket or workflow based systems
as well
- The S/MIME handling should be limited to the gateway because the
internal certstores are not managed and might not have the CAs needed
or more than desiredFurthermore this would be easier to support within organisations using
many different mailclients with many different UIs showing signed
messages in many different ways.But as you noticed it has also disadvantegs. The user should not learn
to blindly rely on a subject Tag. But in pratice most of them do not
see any difference between a subject Tag and a "signed" Icon in there
mailclient anywayIf it is not too much work, i'll vote for it...
--
Djigzo open source email encryption
Do Okt 27 2011 10:32:06 CEST von "Martijn Brinkers" <martijn(a)djigzo.com>
Betreff: Re: Notify about a successfully complete forsigncheckI guess something like a "[Signed]" tag in the subject to show the end
user (internal recipient) that the message was signed and could be
verified when hitting the Djigzo Gateway.Thank you Andreas, yes, this is exactly what i mean.
This is not (yet?) supported. The main question is where are you using
the tag for? The reason I'm asking is that a tag line can lead to a
false sense of security. For example suppose an external sender sends a
non-signed message that contains the tag [Signed] in the subject?
You might argue that all incoming email should be scanned for such a tag
and have the tag be removed. Ok, then what about [ signed ]? Again you
might argue that the scanning should work on a regular expression and
should skip all spaces. Ok, then I come up with the following example,
{Signed}, or just Signed, or Signd.
Just as long as your end-users just use the tag as an indication that
the message *might* be signed, this should not be a problem. The problem
starts when end-users *assume* the message is signed and trusted because
the subject contains some kind of tag.The best way to detect whether a message is signed and is trusted is by
using an S/MIME capable email client. If however you are not using an
S/MIME capable email client or are stripping the S/MIME signatures this
won't help. The gateway will however add certain header fields which
indicate whether the email is signed and whether the signature was
trusted/valid etc. Appendix A of the "S/MIME setup guide" briefly
explains these headers. Since all X-Djigzo-* headers are removed from
any incoming email, those headers cannot be spoofed. The trouble however
with these headers is that it's hard for end-users to read and interpret.To conclude, I'm not saying that adding some kind of keyword/tag to the
subject should never be done. But, you should be careful on what it
means for your end-users when the subject contains a certain keyword/tag.What is currently missing is a mailet (a mailet is a small piece of
software that handles an email) that can add something to the current
subject of a message. I will add this to the todo list. If such a mailet
is available, you can add this functionality to the xml mail flow
specification and match when the email contains the keywords. This might
actually be done with Postfix as a workaround.One last question, is there a reason you cannot use an S/MIME email
client to check the signatures?Kind regards,
Martijn Brinkers
--
Djigzo open source email encryption
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http://lists.djigzo.com/lists/listinfo/users
ok, thank you for your detailed answer! i have understand the problem with a
tag in subject and the possibility of fake. An other way to give the
(intern) user a notice about a successfull signcheck may be send a special
mail with subject related to the original mail, analog the notice about an
successfull encryption.
Kind regards
Matthias
On 10/27/2011 09:25 AM, matthiasdort wrote: