Regardless of whether the original message is signed
or not, the reference element of a signed acknowledgment
SHOULD ALWAYS be computed, not copied from the original message,
by the receiving party.
I don't think that we can say MUST in this situation
but it is a REALLY BAD IDEA to simply copy the received
digest in this case.
Cheers,
Chris
Arvola Chan wrote:
> I was originally objecting to the following statement on line 1557:
>
> "If the original message is not signed, the [XMLDSIG] Reference element must
> be derived from the original message (see section 4.1.3)."
>
> I think the use of "must" is too strong. Is it conceivable that a receiver
> MSH may have the policy of not returning a signed Acknowledgment unless the
> original message is also signed? I think it should be allowed to return an
> error or warning indicating an error code of Inconsistent or NotSupported.
> It should also be allow to comply with the signed AckRequested directive if
> it chooses to.
>
> Regarding Rich's comment that a service may want to sign everything it
> generates, an Acknowledgment message can always be signed. The issue is
> whether the Acknowledgment element needs to include ds:Reference elements
> that contain digests for the MIME parts of the original message. I don't
> think it is reasonable to mandate that the receiver MUST calculate the
> digests if they were not included in the original message in the first
> place.
>
> Regards,
> -Arvola
>
>
