On 11/28/2012 3:34 AM, Pim van der Eijk wrote:
Hello,
Section 5.1.8 describes two formats for receipts:
- Receipts for
reception awareness: those use the UserMessage of the
received message (rather than an empty
NonRepudiationInformation structure as below in (2)).
- Receipts for
nonrepudiation of receipt: those use the ebBP
Non-Repudiation element with ds:Reference elements.
If the NRR is for a
signed message, these ds:Reference elements can be reused
from the wsse:Signature in the message being acknowledged.
This has the advantage that the AS4/ebMS3 parts of an MSH
need to know nothing about creating message digests, only
about XML processing (see the XSLT in the appendix). All
the security processing is done in the WS-Security module.
Good reminder about the encapsulation
of the various processing aspects of modular approach of
the spec. That is an
advantage of ebMS3/AS4.
Perhaps in theory (I
would need to check) the spec allows a situation where NRR
is requested for an unsigned message, in that case the AS4
module would have to create those ds:References itself
including Digests (which the XSLT does not do), but that
would be an unusual case.
Perhaps in the theory from a technical/spec
perspective, but from a legal perspective my understanding
is the conditions of NRR is generally not met unless both the user message and the receipt is signed. Not
saying that trading relationships can
define NRR in such a way that unsigned messages are
acceptable, but verification of origin is
generally a legal requirement for NRR.
Pim
From:
[mailto:] On Behalf Of Jacques
Durand
Sent: 27 November 2012 23:31
To: ;
Subject: RE: [ebxml-msg] AS4 spec clarification on
receipts
Tim:
1. Is setting
PMode.Security.SendReceipt.NonRepudiation = false a
non-conformant configuration with respect to the ebHandler
conformance profile? In other words, does the ebHandler
profile effectively require the sending of signed user
messages and the return of a signed receipt containing a
populated ebBP-SIG infoset, or does the ebHandler profile just
mean that ebBP-SIG infoset is required in the receipt even if
it is empty (either because the user message was unsigned or
because the PMode non-repudiation parameter = false)?
In my
view, the latter is true: the profile does not impose a
particular value for the
PMode.Security.SendReceipt.NonRepudiation parameter, so its
value remains a configuration choice at usage time. (in
fact, I notice that the PMode section 2.1.3.6 does not even
mention this parameter – it should). The only requirement
here is how the Receipt must be formed, not its usage.
2. What would the
XML of the receipt look like for a Pmode non-repudiation
parameter = false look like?
This parameter =false means that Receipts
are only to be used for “reception awareness” if any (but if
the other parameter PMode[1].Security.SendReceipt is not set or set to false, then no
reception awareness is intended and then no Receipt at all
needs be sent). I’d say it should look like this and even <ebbp:NonRepudiationInformation/>
should not have to be there, but I
leave it to a schema check to decide of this:
3. <eb3:Messaging S12:mustUnderstand="true"
id="ValueOfMessagingHeader">
4. <eb3:SignalMessage>
5. <eb3:MessageInfo>
6. <eb3:Timestamp>2009-11-06T08:00:09Z</eb3:Timestamp>
7. <eb3:MessageId></eb3:MessageId>
8. <eb3:RefToMessageId></eb3:RefToMessageId>
9. </eb3:MessageInfo>
10. <eb3:Receipt>
11. <ebbp:NonRepudiationInformation/>
12. </eb3:Receipt>
13. </eb3:SignalMessage>
14. </eb3:Messaging>
15.
-jacques
From:
[mailto:] On Behalf Of
Timothy Bennett
Sent: Tuesday, November 27, 2012 11:57 AM
To:
Subject: [ebxml-msg] AS4 spec clarification on
receipts
Hey folks,
Would like everyone's thoughts on the following clarification
needed from the AS4 profile:
From Section 2.1 on the ebHandler Conformance Profile:
“Use of the
ebbpsig:NonRepudiationInformation element (as defined in
[ebBP-SIG]) is REQUIRED as content for the eb:Receipt
message, i.e. when conforming to this profile a Receiving MSH
must be able to create a Receipt with such a content, and a
Sending MSH must be able to process it.”
Further, in Section 5.2.1, the spec suggests
a usage:
“For
non-repudiation, the eb:Receipt
element must contain a well-formed
ebbpsig:NonRepudiationInformation element.
This is indicated by the new P-Mode parameter:· PMode[1].Security.SendReceipt.NonRepudiation
: value = ‘true' (to be used for
non-repudiation of receipt), value = 'false' (to be used
simply for reception awareness).”
So, here's my
couple of questions:
16. Is setting
PMode.Security.SendReceipt.NonRepudiation = false a
non-conformant configuration with respect to the ebHandler
conformance profile? In other words, does the ebHandler
profile effectively require the sending of signed user
messages and the return of a signed receipt containing a
populated ebBP-SIG infoset, or does the ebHandler profile just
mean that ebBP-SIG infoset is required in the receipt even if
it is empty (either because the user message was unsigned or
because the PMode non-repudiation parameter = false)?
17. What would the
XML of the receipt look like for a Pmode non-repudiation
parameter = false look like?
Would it be just an empty eb3:Receipt infoset (like below),
or would it also contain an empty
ebbpsig:Non-RepudiationInformation infoset?
<eb3:Messaging
S12:mustUnderstand="true" id="ValueOfMessagingHeader">
<eb3:SignalMessage>
<eb3:MessageInfo>
<eb3:Timestamp>2009-11-06T08:00:09Z</eb3:Timestamp>
<eb3:MessageId></eb3:MessageId>
<eb3:RefToMessageId></eb3:RefToMessageId>
</eb3:MessageInfo>
<eb3:Receipt>
</eb3:Receipt>
</eb3:SignalMessage>
</eb3:Messaging>
