Trying to do authentication with LDAP from iRule, not working

when CLIENT_ACCEPTED {
                 Generate a timestamp for the log message below
                set myIntTime [clock format [clock seconds] -format "%Y-%m-%d_%H:%M:%S %z"]
                log local0. " ==================== BEGIN ========= $myIntTime =========== "
}

when HTTP_REQUEST {
                log local0. " BEGIN ========= HTTP_REQUEST"
                log local0. " === Auth Step 1"
                if {not [info exists tmm_auth_http_sids(ldap)]} {
                                log local0. " === Auth Step 2"
                                set tmm_auth_sid [AUTH::start pam default_ldap]
                                log local0. " tmm_auth_sid : $tmm_auth_sid"
                                set tmm_auth_http_sids(ldap) $tmm_auth_sid
                                log local0. " === Auth Step 3"
                                if {[info exists tmm_auth_subscription]} {
                                                log local0. " === Auth Step 4"
                                                AUTH::subscribe $tmm_auth_sid
                                }
                } else {
                                log local0. " === Auth Step 5"
                                set tmm_auth_sid $tmm_auth_http_sids(ldap)
                                log local0. " tmm_auth_sid : $tmm_auth_sid"
                }

                set user [HTTP::username]
                set pass [HTTP::password]
                log local0. " Auth using -$user- and -$pass-"
                log local0. " === Auth Step 6"
                AUTH::username_credential $tmm_auth_sid [HTTP::username]
                log local0. " === Auth Step 7"
                AUTH::password_credential $tmm_auth_sid [HTTP::password]
                log local0. " === Auth Step 8"
                AUTH::authenticate $tmm_auth_sid
                log local0. " === Auth Step 9"
                if {not [info exists tmm_auth_http_collect_count]} {
                                log local0. " === Auth Step 10"
                                HTTP::collect
                                log local0. " === Auth Step 11"
                                set tmm_auth_http_successes 0
                                set tmm_auth_http_collect_count 1
                } else {
                                log local0. " === Auth Step 12"
                                incr tmm_auth_http_collect_count
                }
                log local0. " END   ========= HTTP_REQUEST"
}

when AUTH_RESULT {
                log local0. " BEGIN ========= AUTH_RESULT"
                log local0. " === Auth Step 13"
                set status [AUTH::status]
                log local0. " === Auth Step 14"
                log local0. " AuthStatus is: -$status-"
                if {not [info exists tmm_auth_http_sids(ldap)] or \
                ($tmm_auth_http_sids(ldap) != [AUTH::last_event_session_id]) or \
                (not [info exists tmm_auth_http_collect_count])} {
                                log local0. " === Auth Step 15"
                                return
                }
                log local0. " === Auth Step 16"
                if {[AUTH::status] == 0} {
                                log local0. " === Auth Step 17"
                                incr tmm_auth_http_successes
                }
                 If multiple auth sessions are pending and
                 one failure results in termination and this is a failure
                 or enough successes have now occurred
                if {([array size tmm_auth_http_sids] > 1) and \
                ((not [info exists tmm_auth_http_sufficient_successes] or \
                ($tmm_auth_http_successes >= $tmm_auth_http_sufficient_successes)))} {
                                log local0. " === Auth Step 18"
                                 Abort the other auth sessions
                                foreach {type sid} [array get tmm_auth_http_sids] {
                                                log local0. " === Auth Step 19"
                                                unset tmm_auth_http_sids($type)
                                                if {($type ne "ldap") and ($sid != -1)} {
                                                                log local0. " === Auth Step 20"
                                                                AUTH::abort $sid
                                                                incr tmm_auth_http_collect_count -1
                                                }
                                }
                                log local0. " === Auth Step 21"
                }
                log local0. " === Auth Step 22"

                 If this is the last outstanding auth then either
                 release or respond to this session
                incr tmm_auth_http_collect_count -1
                if {$tmm_auth_http_collect_count == 0} {
                                log local0. " === Auth Step 23"
                                unset tmm_auth_http_collect_count
                                if {[AUTH::status] == 0} {
                                                log local0. " === Auth Step 24"
                                                HTTP::release
                                } else {
                                                log local0. " === Auth Step 25"
                                                HTTP::respond 401
                                }
                                log local0. " === Auth Step 26"
                }
                log local0. " END   ========= AUTH_RESULT"
}

when HTTP_RESPONSE {
                log local0. " BEGIN ========== HTTP_RESPONSE"
                 For Click-Jacking protection
                HTTP::header insert "X-FRAME-OPTIONS" "(DENY || SAMEORIGIN)"

                 Capture the response time for logging
                set latency [expr {[clock clicks -milliseconds] - $reqIntLatency}]
                log local0. " Call Latency: -$latency- milliseconds "
                log local0. " ==================== END ========= $myIntTime =========== "
}