Re: (ITS#5977) pcache and broken Active Directory equality matching rules

[ando@sys-net.it]

mhardin@symas.com wrote:
> Full_Name: Matthew Hardin
> Version: 2.4.14
> OS: RHEL4 x86
> URL: ftp://ftp.openldap.org/incoming/
> Submission from: (NULL) (74.44.226.116)
> 
> 
> Given an Active Directory group object containing the following two members:
> 
> member: cn=Frank Y. Ewe,ou=Important Accounts,ou=User
> Accounts,ou=Common,dc=ad,dc=foobar,dc=com
> 
> and
> 
> member: cn=Frank  Y. Ewe,ou=Important Accounts,ou=User
> Accounts,ou=Common,dc=ad,dc=foobar,dc=com
> 
> (note the extra space between "Frank" and "Y" in the second member)
> 
> Active Directory sees these as different entries and allows them to both be
> members of the same group. Back-LDAP and back-meta happily return both of these
> values.

I'd expect slapd-ldap to return two identical values, since value 
prettification also eliminates multiple spaces in directoryString values.

> When 'sortvals member' is turned on, the pcache overlay will cache this value
> but will not return it on subsequent searches because it sees these two values
> as duplicates. According to Howard Chu, this is because the equality matching
> rule for the 'member' attribute collapses multiple spaces into one before doing
> the comparison and so reports these two values as duplicates.
> 
> Howard asked me to file this ITS as a means to solicit guidance from others as
> to the best way/place to fix this.

After value normalization, slapd-ldap I think should also check for 
duplicates (possibly leaving this as an option), and discard them.  In 
fact, it is the proxy backend that injects broken data into the loop.

Of course, the best solution in your case would probably be to fix your 
data... :)

p.


Ing. Pierangelo Masarati
OpenLDAP Core Team

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