RADIUS server using APM to authenticate users

Kai,

to make it more elegant, I changed the decoding code to (all attributes are stored in a array with ID as key)

for {set record_offset 0} {$QLEN - $record_offset > 20} {incr record_offset $QAVP_LEN} {
   binary scan $QAVP @${record_offset}cc QAVP_TYPE QAVP_LEN
   binary scan $QAVP @${record_offset}x2a[expr {$QAVP_LEN -2}] QUERY_ATTR($QAVP_TYPE)
   if {$QAVP_TYPE == 80} {
        set UNSIGNED_RAVP [string replace $QAVP $record_offset [expr {$record_offset + 18}] [binary format ccH32 80 18 [string repeat 0 32]]]
        set UNSIGNED_REQUEST [binary format cH2Sa16a* $QCODE $QID $QLEN $Q_AUTHENTICATOR $UNSIGNED_RAVP]
  }
} 

then each required attribute is copied to the expected variable

set USER_NAME [expr {[info exists QUERY_ATTR(1)] ? $QUERY_ATTR(1) : ""}]
set USER_PASSWORD [expr {[info exists QUERY_ATTR(2)] ? $QUERY_ATTR(2) : ""}]
set CHAP_PASSWORD [expr {[info exists QUERY_ATTR(3)] ? $QUERY_ATTR(3) : ""}]