opts.claims[ldapUserN] = targetUser // simple username
		targetUser, targetGroups, err = globalIAMSys.LDAPConfig.LookupUserDN(targetUser)
		if err != nil {
			// if not found, check if DN
			if strings.Contains(err.Error(), "User DN not found for:") {
				if isDN {
					// warn user that DNs are not allowed
					writeErrorResponseJSON(ctx, w, errorCodes.ToAPIErrWithErr(ErrAdminLDAPExpectedLoginName, err), r.URL)
				} else {