RADIUS authentication packet manipulation library

Hi,

I suggest this code for encoding / decoding

proc pw_decrypt { KEY Q_AUTHENTICATOR ENCODED_PASSWORD } {
  binary scan [md5 $KEY$Q_AUTHENTICATOR] WW bx_64bits_1 bx_64bits_2
  binary scan $ENCODED_PASSWORD W* ENCODED_PASSWORD_W_LIST
  set PASSWORD_LIST [list]
  foreach {cx_64bits_1 cx_64bits_2} $ENCODED_PASSWORD_W_LIST {
    lappend PASSWORD_LIST [expr { $cx_64bits_1 ^ $bx_64bits_1 }] [expr { $cx_64bits_2 ^ $bx_64bits_2 }]
    binary scan [md5 $KEY[binary format WW $cx_64bits_1 $cx_64bits_2]] WW bx_64bits_1 bx_64bits_2
  }
  binary scan [binary format W* $PASSWORD_LIST] A* PASSWORD
  return $PASSWORD
}


proc pw_encrypt { KEY Q_AUTHENTICATOR PASSWORD } {
  binary scan [md5 $KEY$Q_AUTHENTICATOR] WW bx_64bits_1 bx_64bits_2
  binary scan [binary format a[expr {[string length $PASSWORD] + 16 - [string length $PASSWORD]%16}] $PASSWORD ] W* PASSWORD_W_LIST
  set ENCODED_PASSWORD_LIST [list]
  foreach {px_64bits_1 px_64bits_2} $PASSWORD_W_LIST {
  log local0. "$px_64bits_1 ^ $bx_64bits_1"
    lappend ENCODED_PASSWORD_LIST [expr { $px_64bits_1 ^ $bx_64bits_1 }] [expr { $px_64bits_2 ^ $bx_64bits_2 }]
    binary scan [md5 $KEY[binary format W2 [lrange $ENCODED_PASSWORD_LIST end-1 end]]] WW bx_64bits_1 bx_64bits_2
  }
  binary scan [binary format W* $ENCODED_PASSWORD_LIST] A* ENCODED_PASSWORD
  return $ENCODED_PASSWORD

}

and to get AUTHENTICATOR , use this command: instead if string range...

binary scan [UDP::payload] @4a16 Q_AUTHENTICATOR