Searching with empty attribute value results in an invalid filter error

[skloepp2]

Description

I want to find invalid objects in our directory which have a mail attribute set with an empty value => mail=""
My LDAP Filter is (mail=) which is working in Apache Directory Studio or third party ldap libraries.
After switching back to system.directoryservices.protocolls, these ldap queries are failing with "invalid ldap filter".

Reproduction Steps

Execute a SearchRequest with filter => "(mail=)" the result is a "invalid ldap filter" error

Expected behavior

No error

Actual behavior

"invalid ldap filter" error occours

Regression?

No response

Known Workarounds

Using filter (mail=\00) works and finds objects with an empty value.

Configuration

No response

Other information

No response

Tagging subscribers to this area: @dotnet/area-system-directoryservices, @jay98014
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Issue Details

---

Description

I want to find invalid objects in our directory which have a mail attribute set with an empty value => mail=""
My LDAP Filter is (mail=) which is working in Apache Directory Studio or third party ldap libraries.
After switching back to system.directoryservices.protocolls, these ldap queries are failing with "invalid ldap filter".

Reproduction Steps

Execute a SearchRequest with filter => "(mail=)" the result is a "invalid ldap filter" error

Expected behavior

No error

Actual behavior

"invalid ldap filter" error occours

Regression?

No response

Known Workarounds

No response

Configuration

No response

Other information

No response

Author:	skloepp2
Assignees:	-
Labels:	area-System.DirectoryServices
Milestone:	-

[steveharter]

Does (!mail=*) work?

This issue has been marked needs-author-action and may be missing some important information.

[skloepp2]

Does (!mail=*) work?

No that would not be a valid ldap filter. (!(mail=*)) is what you mean, but that would find all objects without a value in mail. What I an looking for is for objects with an empty value set. The workaround is as mentioned (mail=\00).

[steveharter]

Does mail=\00 work on Apache Directory Studio and the third party ldap libraries you mentioned earlier?

Also are you on Windows or a version of Linux (or both)?

[skloepp2]

mail=\00 is a workaround for System.DirectoryServices.Protocolls. But it also works on third party libraries and Apache Directory Studio.

I'm developing on both Windows and Linux.

[steveharter]

Pinging System.DirectoryServices consultants @BRDPM @grubioe @jay98014 for thoughts on this. Thanks.

[BRDPM]

Hi there! Is there any reason the workaround isn't sufficient?