Re: uid -- unique or user?

Mark Wahl (
Thu, 12 Sep 1996 17:41:44 -0500

> There seems to be some ambiguity with regard to the attribute UID --
> X.520 seems to refer to it as the "uniqueIdentifier." But various
> discussions in this forum, client apps, and other UMich documents
> seem to be using it as the userID.

I think uid in LDAP should mean the RFC 1274 attribute userid, a login name.

'uid' in X.520(93) is only used in the context of NameAndOptionalUID. The
standard names the attribute with BIT STRING syntax 'uniqueIdentifier'.

However because of the clash of _this_ name between 1274 and X.520(93), I
suggest in LDAP calling the attribute number from X.520(93) with
BIT STRING syntax 'x500UniqueIdentifier',
and the attribute number 0.9.2342.19200300.100.1.44 from RFC 1274 with string
syntax 'pilotUniqueIdentifier' or 'uniqueIdentifier'.

Most LDAP implementations today I believe call the RFC 1274 attribute
0.9.2342.19200300.100.1.1 'uid' or 'userid', and the RFC 1274 attribute
0.9.2342.19200300.100.1.44 'uniqueIdentifier', and do not recognize the
attribute with any string name, since it was not in X.520(88).

Clear ... as mud?

Mark Wahl, Enterprise Directory Integration
Critical Angle Incorporated