_require_called_aet should be a boolean value, rather than a string.

[raulAtNines]

Description

It is possible to set a require_called_aet different from the ae_title for the same AE.

Expected behaviour

ae_title and the required ae title should be the same.

Actual behaviour

ae_title is irrelevant for purposes of requiring ae_title matching.

Steps to reproduce

  self.ae = AE(ae_title='MyRealAE',
    port=ae_port,
    scu_sop_class=[],
    scp_sop_class=scp_classes,
    transfer_syntax=transfer_syntax)

  self.ae.require_called_aet = b'ReqAE'

MyRealAE is useless, since clients are required to provide ReqAE.

Suggested: required_called_aet should be a boolean, that if set to True, will use the current ae_title for the comparison.

Your environment

Irrelevant.

[scaramallion]

Are there any use cases where someone would want to validate against a Called AE Title that differs from the actual AE title?

[raulAtNines]

According to dicom part 8, chapter 7 http://dicom.nema.org/medical/dicom/2017b/output/chtml/part08/chapter_7.html

7.1.1.3 Calling AE Title
...It is based on the Source DICOM Application Name...

7.1.1.4 Called AE Title
...It is based on the Destination DICOM Application Name... 

The relationship between DICOM Application Name and AE titles is specified in Annex C. 

Annex C: http://dicom.nema.org/medical/dicom/2017b/output/chtml/part08/chapter_C.html

...
DICOM Application Entity Titles are used in three instances of communication:
+ to identify the Called/Calling Application Entities. They are used to establish an association and to ensure that the association is established with the expected application.
...

It would seem that the Called AE Title is expected to be (one of) the actual AE Title(s) of the receiver.

I can't think of an instance where that's not true. But I am no expert in the standard.

[scaramallion]

Its actually frequently the case where Called AE Title doesn't match, just that most implementations don't both enforcing it. I'll think about possible use cases a bit more but I think what you've suggested is reasonable.

[raulAtNines]

What do you mean it's frequently the case that they don't match?

According to Annex C it's the receiver's responsibility to make sure the association provided one, and the registered ones do match:

7.1.1.3 Calling AE Title
This parameter identifies ...
Note
It is the responsibility of the UL User that received the A-ASSOCIATE-RQ to verify whether the Calling AE Title is one of its known remote DICOM Application Names.

7.1.1.4 Called AE Title
This parameter identifies...
Note
It is the responsibility of the UL User that received the A-ASSOCIATE-RQ to verify whether the Called AE Title is its (or one of its) DICOM Application Name(s).

[scaramallion]

Sure but in the real world (which doesn't always follow the DICOM standard), its frequently the case that SCPs don't care what the supplied Called/Calling AE Title is.

[raulAtNines]

Right, right. That's why I suggested turning it into a boolean, rather than being able to specify a different name from the ae title.

[raulAtNines]

Awesome, thanks!