This fixes #3748 by allowing reserved characters in `bind_dn` (and
other properties of the same format) if they are properly quoted and
adds some corresponding documentation regarding that.
This was tested by setting up a slapd server and creating a user with
the CN `Test, User` much like in the bug report, then using this user
as `bind_dn` in the sync options. I also tested some variants of that
CN, including just `TestUser`.)
One thing that still won't work is syncing of LDAP users with colons
or slashes in their CNs. In such cases, the message
> value 'Test, User@ldap' does not look like a valid user name
will pop up.
This is due to spaces and colons being explicitly disallowed in
usernames by PVE access-control's username schema. This probably
means that such names can never be allowed, which is being documented
too as separate pve-docs patch.
Note that while this is now a bit more strict for some cases too,
they should not matter in practice. For context; see RFC 2253 [0],
section 4. Interestingly, this document was obsoleted by RFC 4514 [1]
in 2006, which only mentions this in section 2.4 ("Converting an
AttributeValue from ASN.1 to a String") and appendix A ("Presentation
Issues").
But the first one seems to be the "authoritive" document on this
matter, at least looking at some other docs about LDAP DNs (RedHat,
Microsoft, ..).