1 files changed, 161 insertions, 0 deletions
diff --git a/scripts/iec-identify.nse b/scripts/iec-identify.nse
new file mode 100644
index 0000000..81bcd61
--- /dev/null
+++ b/scripts/iec-identify.nse
@@ -0,0 +1,161 @@
+local shortport = require "shortport"
+local comm = require "comm"
+local stdnse = require "stdnse"
+local string = require "string"
+local match = require "match"
+
+description = [[
+Attempts to identify IEC 60870-5-104 ICS protocol.
+
+After probing with a TESTFR (test frame) message, a STARTDT (start data
+transfer) message is sent and general interrogation is used to gather the list
+of information object addresses stored.
+]]
+
+---
+-- @output
+-- | iec-identify:
+-- |   ASDU address: 105
+-- |_  Information objects: 30
+--
+
+author = {"Aleksandr Timorin", "Daniel Miller"}
+license = "Same as Nmap--See https://nmap.org/book/man-legal.html"
+categories = {"discovery", "intrusive"}
+
+portrule = shortport.port_or_service(2404, "iec-104", "tcp")
+
+local function get_asdu(socket)
+  local status, data = socket:receive_buf(match.numbytes(2), true)
+  if not status then
+    return nil, data
+  end
+  if data:byte(1) ~= 0x68 then
+    return nil, "Not IEC-104"
+  end
+  local len = data:byte(2)
+  status, data = socket:receive_buf(match.numbytes(len), true)
+  if not status then
+    return nil, data
+  end
+  local apcitype = data:byte(1)
+  return apcitype, data
+end
+
+action = function(host, port)
+
+  local output = stdnse.output_table()
+  local socket, err = comm.opencon(host, port)
+  if not socket then
+    stdnse.debug1("Connect error: %s", err)
+    return nil
+  end
+
+  -- send TESTFR ACT command
+  -- Test frame, like "ping"
+  local TESTFR = "\x68\x04\x43\0\0\0"
+  local status, err = socket:send( TESTFR )
+  if not status then
+    stdnse.debug1("Failed to send: %s", err)
+    return nil
+  end
+
+  -- receive TESTFR answer
+  local apcitype, recv = get_asdu(socket)
+  if not apcitype then
+    stdnse.debug1("protocol error: %s", recv)
+    return nil
+  end
+  if apcitype ~= 0x83 then
+    stdnse.print_debug(1, "Not IEC-104. TESTFR response: %#x", apcitype)
+    return nil
+  end
+
+  -- send STARTDT ACT command
+  local STARTDT = "\x68\x04\x07\0\0\0"
+  status, err = socket:send( STARTDT )
+  if not status then
+    stdnse.debug1("Failed to send: %s", err)
+    return nil
+  end
+
+  -- receive STARTDT answer
+  apcitype, recv = get_asdu(socket)
+  if not apcitype then
+    stdnse.debug1("protocol error: %s", recv)
+    return nil
+  end
+  if apcitype ~= 0x0b then
+    stdnse.debug1("STARTDT ACT did not receive STARTDT CON: %#x", apcitype)
+    return nil
+  end
+
+  -- May also receive ME_EI_NA_1 (End of initialization), so check for that in the buffer after sending the next part
+
+  -- send C_IC_NA_1 command
+  -- type: 0x64, C_IC_NA_1,
+  -- numix: 1
+  -- TNCause: 6, Act
+  -- Originator address; 0
+  -- ASDU address: 0xffff
+  -- Information object address: 0
+  -- QOI: 0x14 (20), Station interrogation (global)
+  local C_IC_NA_1_broadcast = "\x68\x0e\0\0\0\0\x64\x01\x06\0\xff\xff\0\0\0\x14"
+  status, err = socket:send( C_IC_NA_1_broadcast )
+  if not status then
+    stdnse.debug1("Failed to send: %s", err)
+    return nil
+  end
+
+  local asdu_address
+  local ioas = 0
+  -- Have to draw the line somewhere.
+  local limit = 10
+  while limit > 0 do
+    limit = limit - 1
+    apcitype, recv = get_asdu(socket)
+    if not apcitype then
+      stdnse.debug1("Error in C_IC_NA_1: %s", recv)
+      break
+    end
+    if apcitype & 0x01 == 0 then -- Type I, numbered information transfer
+      -- skip 2 bytes Tx, 2 bytes Rx
+      local typeid = recv:byte(5)
+      if typeid == 70 then
+        -- ME_EI_NA_1, End of Initialization. Skip.
+      else
+        local numix = recv:byte(6) & 0x7f
+        local cause = recv:byte(7) & 0x3f
+        asdu_address = string.unpack("<I2", recv, 9)
+        stdnse.debug2("Got asdu=%d, type %d, cause %d, numix %d.", asdu_address, typeid, cause, numix)
+        if typeid == 100 then
+          -- C_IC_NA_1
+          if cause == 7 then
+            -- ActCon. Skip.
+          elseif cause == 10 then
+            -- ActTerm. The end!
+            break
+          else
+            -- TODO: do something!
+          end
+        else
+          if cause >= 20 and cause <= 36 then
+            -- Inrogen, response to general interrogation
+            ioas = ioas + numix
+          end
+        end
+      end
+    end
+  end
+
+  socket:close()
+
+  if asdu_address then
+    output["ASDU address"] = asdu_address
+    output["Information objects"] = ioas
+  else
+    output = "IEC-104 endpoint did not respond to C_IC_NA_1 request"
+  end
+
+  return output
+end