Dina léngkah tina Industrial Ninja: kumaha PLC diretas dina Positive Hack Days 9

Dina PHDays 9 panungtungan urang ngayakeun kompetisi hack pabrik pompa gas - kompetisi Ninja Industri. Aya tilu lapak dina situs kalayan parameter kaamanan béda (No Kaamanan, Kaamanan Low, Kaamanan High), emulating prosés industri sarua: hawa pressurized ieu ngompa kana balon a (lajeng dileupaskeun).

Sanajan parameter kaamanan béda, komposisi hardware lapak éta sarua: Siemens Simatic PLC S7-300 runtuyan; tombol deflation darurat sarta alat ukur tekanan (dihubungkeun jeung PLC inputs digital (DI)); valves operasi pikeun inflasi na deflation hawa (dihubungkeun jeung outputs digital tina PLC (DO)) - tingali gambar di handap.

PLC, gumantung kana bacaan tekanan sareng saluyu sareng programna, nyandak kaputusan pikeun ngempiskeun atanapi ngagedekeun bal (dibuka sareng ditutup klep anu saluyu). Sanajan kitu, sagala lapak boga mode kontrol manual, nu ngamungkinkeun pikeun ngadalikeun kaayaan valves tanpa palarangan.

Stands béda dina pajeulitna ngaktipkeun mode ieu: dina stand nu teu dijagi éta panggampangna pikeun ngalakukeun ieu, sarta di stand Kaamanan Luhur éta correspondingly leuwih hese.

Lima tina genep masalah direngsekeun dina dua poé; Pamilon tempat kahiji earned 233 titik (anjeunna spent saminggu Nyiapkeun pikeun kompetisi). Tilu winners: Kuring nempatkeun - a1exdandy, II - Rubikoid, III - Ze.

Nanging, salami PHDays, teu aya pamilon anu tiasa ngatasi sadaya tilu stand, janten kami mutuskeun pikeun ngadamel kompetisi online sareng nyebarkeun tugas anu paling hese dina awal Juni. Pamilon kedah ngarengsekeun tugas dina sabulan, milarian bandéra, sareng ngajelaskeun solusina sacara rinci sareng cara anu pikaresepeun.

Handap cut kami nyebarkeun analisa solusi pangalusna pikeun tugas ti nu dikirim ngaliwatan bulan, kapanggih ku Alexey Kovrizhnykh (a1exdandy) ti parusahaan Kaamanan Digital, anu nyokot tempat XNUMXst dina kompetisi salila PHDays. Di handap ieu kami nampilkeun téks na sareng koméntar kami.

Analisis awal

Janten, tugasna ngandung arsip sareng file ieu:

• block_upload_traffic.pcapng
• DB100.bin
• pitunjuk.txt

File hints.txt ngandung inpormasi anu dipikabutuh sareng petunjuk pikeun ngabéréskeun tugas. Ieu eusina:

1. Petrovich ngawartoskeun kuring kamari yén anjeun tiasa ngamuat blok ti PlcSim kana Step7.
2. Siemens Simatic S7-300 séri PLC dipaké dina stand.
3. PlcSim mangrupikeun émulator PLC anu ngamungkinkeun anjeun ngajalankeun sareng debug program pikeun PLC Siemens S7.

Berkas DB100.bin sigana ngandung blok data DB100 PLC: 00000000: 0100 0102 6e02 0401 0206 0100 0101 0102 ....n......... 00000010: 1002 0501 0202e2002 0501 0206 0100 0102 00000020 ....n......... 0102: 7702 0401 0206e0100 0103 0102 0 02 00000030 ....n......... 0501: 0202 1602 0501 0206 0100 . ..... ......... 0104: 0102 00000040 7502 0401 0206 0100 0105 0102a0 ..w............. 02: 0501 00000050 0202 1602 0501 0206 0100 0106 ................ 0102: 3402 4 00000060 0401 0206 0100 0107a0102 2602 u............... 0501: 0202 00000070 4 02 0501 0206 0100 0108............0102. 3302: 0401 3 00000080 0206 0100 0109 0102 0 .........&..... 02: 0501c0202 1602 00000090 0501 0206 0100 . : 010 0102 3702 0401 0206a7 000000 0 0100 ................ 010: 0102 2202 0501 0202a 4602 0501 000000 0 .........0206. 0100a010: 0102 3302b 0401 0206 0100 3 000000 0 ......".....F... 010b0102: 0 02 0501c 0202 1602 0501 .......0206 000000 ........ .. 0c0100: 010d 0102 6a02 0401 0206 0100 010 000000 ................ 0d0102: 1102 0501e 0202 2302d0501 0206 0100 000000 .... .... 0e0110: 0102 3502 0401 0206 0100 0111 0102 5 ........#...... 00000100f1202: 0501 0202 2502 0501 0206 0100 ..0112 ..... ..... 00000110: 0102 3302 0401 0206 0100 0113 0102 2602 ......%......... 3: 00000120 0501 0202 4 02 0501 .0206 0100 .. .....&. XNUMX: XNUMX XNUMX XNUMXcXNUMX XNUMX XNUMX XNUMX ....L......

Sakumaha ngaranna nunjukkeun, file block_upload_traffic.pcapng ngandung dump lalulintas unggah block ka PLC.

Eta sia noting yén dump lalulintas ieu di situs kompetisi salila konferensi éta saeutik leuwih hese pikeun ménta. Jang ngalampahkeun ieu, perlu ngartos naskah ti file proyék pikeun TeslaSCADA2. Ti dinya éta mungkin ngartos dimana dump énkripsi ngagunakeun RC4 ieu lokasina sarta konci naon diperlukeun pikeun dipaké pikeun ngadekrip eta. Dumps blok data dina situs bisa didapet maké klien protokol S7. Pikeun ieu kuring nganggo klien demo tina pakét Snap7.

Extracting blok processing sinyal ti dump lalulintas

Ningali eusi dump, anjeun tiasa ngartos yén éta ngandung blok pamrosésan sinyal OB1, FC1, FC2 sareng FC3:

Blok ieu kedah dipiceun. Ieu tiasa dilakukeun, contona, nganggo skrip di handap ieu, saatos ngarobih lalu lintas tina format pcapng ka pcap:

#!/usr/bin/env python2

import struct
from scapy.all import *

packets = rdpcap('block_upload_traffic.pcap')
s7_hdr_struct = '>BBHHHHBB'
s7_hdr_sz = struct.calcsize(s7_hdr_struct)
tpkt_cotp_sz = 7
names = iter(['OB1.bin', 'FC1.bin', 'FC2.bin', 'FC3.bin'])
buf = ''

for packet in packets:
    if packet.getlayer(IP).src == '10.0.102.11':
        tpkt_cotp_s7 = str(packet.getlayer(TCP).payload)
        if len(tpkt_cotp_s7) < tpkt_cotp_sz + s7_hdr_sz:
            continue
        s7 = tpkt_cotp_s7[tpkt_cotp_sz:]
        s7_hdr = s7[:s7_hdr_sz]
        param_sz = struct.unpack(s7_hdr_struct, s7_hdr)[4]
        s7_param = s7[12:12+param_sz]
        s7_data = s7[12+param_sz:]
        if s7_param in ('x1ex00', 'x1ex01'):  # upload
            buf += s7_data[4:]
        elif s7_param == 'x1f':
            with open(next(names), 'wb') as f:
                f.write(buf)
            buf = ''

Saanggeus nalungtik blok hasilna, anjeun bakal aya bewara yen aranjeunna salawasna dimimitian ku bait 70 70 (pp). Ayeuna anjeun kedah diajar kumaha nganalisis aranjeunna. Petunjuk ngerjakeun nunjukkeun yén anjeun kedah nganggo PlcSim pikeun ieu.

Meunangkeun parentah nu bisa dibaca manusa tina blok

Kahiji, hayu urang coba program S7-PlcSim ku loading sababaraha blok jeung repeating parentah (= Q 0.0) kana eta ngagunakeun software Simatic Manajer, tur nyimpen PLC diala dina émulator kana file example.plc. Ku ningali eusi file, anjeun tiasa sacara gampil nangtukeun awal blok anu diunduh ku tanda tangan 70 70, anu kami mendakan sateuacana. Sateuacan blok, katingalina, ukuran blok ditulis salaku nilai 4-bait saeutik-endian.

Saatos kami nampi inpormasi ngeunaan struktur file plc, rencana aksi di handap ieu muncul pikeun maca program PLC S7:

1. Ngagunakeun Simatic Manajer, urang nyieun struktur blok di S7-PlcSim sarupa hiji kami nampi ti dump nu. Ukuran blok kedah cocog (ieu dihontal ku ngeusian blok kalayan jumlah paréntah anu diperyogikeun) sareng idéntifikasina (OB1, FC1, FC2, FC3).
2. Simpen PLC kana file.
3. Urang ngaganti eusi blok dina file hasilna jeung blok ti dump lalulintas. Awal blok ditangtukeun ku tanda tangan.
4. Kami ngamuat file anu hasilna kana S7-PlcSim sareng ningali eusi blok dina Manajer Simatic.

Blok bisa diganti, contona, ku kodeu handap:

with open('original.plc', 'rb') as f:
    plc = f.read()
blocks = []
for fname in ['OB1.bin', 'FC1.bin', 'FC2.bin', 'FC3.bin']:
    with open(fname, 'rb') as f:
        blocks.append(f.read())

i = plc.find(b'pp')
for block in blocks:
    plc = plc[:i] + block + plc[i+len(block):]
    i = plc.find(b'pp', i + 1)

with open('target.plc', 'wb') as f:
    f.write(plc)

Alexey nyandak jalan anu langkung hese, tapi tetep leres. Urang nganggap yén pamilon bakal ngagunakeun program NetToPlcSim ambéh PlcSim bisa komunikasi ngaliwatan jaringan, unggah blok ka PlcSim via Snap7, lajeng ngundeur blok ieu salaku proyék ti PlcSim ngagunakeun lingkungan ngembangkeun.

Ku muka file hasilna dina S7-PlcSim, Anjeun bisa maca blok overwritten ngagunakeun Manajer Simatic. Fungsi kontrol alat utama kacatet dina blok FC1. Catetan tinangtu nyaéta variabel #TEMP0, anu nalika dihurungkeun muncul pikeun nyetél kadali PLC ka modeu manual dumasar kana nilai memori bit M2.2 sareng M2.3. Nilai #TEMP0 diatur ku fungsi FC3.

Pikeun ngabéréskeun masalah, anjeun kedah nganalisis fungsi FC3 sareng ngartos naon anu kedah dilakukeun supados uih deui anu logis.

Blok pamrosésan sinyal PLC di stand Kaamanan Low di situs kompetisi anu disusun dina cara nu sarupa, tapi pikeun ngeset nilai variabel #TEMP0, éta cukup nulis garis jalan ninja kuring kana blok DB1. Mariksa nilai dina blok éta lugas jeung teu merlukeun pangaweruh jero ngeunaan basa programming block. Jelas, dina tingkat Kaamanan Luhur, ngahontal kontrol manual bakal langkung sesah sareng kedah ngartos seluk-beluk basa STL (salah sahiji cara pikeun ngaprogram S7 PLC).

Blok ngabalikkeun FC3

Eusi blok FC3 dina perwakilan STL:

      L     B#16#0
      T     #TEMP13
      T     #TEMP15
      L     P#DBX 0.0
      T     #TEMP4
      CLR   
      =     #TEMP14
M015: L     #TEMP4
      LAR1  
      OPN   DB   100
      L     DBLG
      TAR1  
      <=D   
      JC    M016
      L     DW#16#0
      T     #TEMP0
      L     #TEMP6
      L     W#16#0
      <>I   
      JC    M00d
      L     P#DBX 0.0
      LAR1  
M00d: L     B [AR1,P#0.0]
      T     #TEMP5
      L     W#16#1
      ==I   
      JC    M007
      L     #TEMP5
      L     W#16#2
      ==I   
      JC    M008
      L     #TEMP5
      L     W#16#3
      ==I   
      JC    M00f
      L     #TEMP5
      L     W#16#4
      ==I   
      JC    M00e
      L     #TEMP5
      L     W#16#5
      ==I   
      JC    M011
      L     #TEMP5
      L     W#16#6
      ==I   
      JC    M012
      JU    M010
M007: +AR1  P#1.0
      L     P#DBX 0.0
      LAR2  
      L     B [AR1,P#0.0]
      L     C#8
      *I    
      +AR2  
      +AR1  P#1.0
      L     B [AR1,P#0.0]
      JL    M003
      JU    M001
      JU    M002
      JU    M004
M003: JU    M005
M001: OPN   DB   101
      L     B [AR2,P#0.0]
      T     #TEMP0
      JU    M006
M002: OPN   DB   101
      L     B [AR2,P#0.0]
      T     #TEMP1
      JU    M006
M004: OPN   DB   101
      L     B [AR2,P#0.0]
      T     #TEMP2
      JU    M006
M00f: +AR1  P#1.0
      L     B [AR1,P#0.0]
      L     C#8
      *I    
      T     #TEMP11
      +AR1  P#1.0
      L     B [AR1,P#0.0]
      T     #TEMP7
      L     P#M 100.0
      LAR2  
      L     #TEMP7
      L     C#8
      *I    
      +AR2  
      TAR2  #TEMP9
      TAR1  #TEMP4
      OPN   DB   101
      L     P#DBX 0.0
      LAR1  
      L     #TEMP11
      +AR1  
      LAR2  #TEMP9
      L     B [AR2,P#0.0]
      T     B [AR1,P#0.0]
      L     #TEMP4
      LAR1  
      JU    M006
M008: +AR1  P#1.0
      L     B [AR1,P#0.0]
      T     #TEMP3
      +AR1  P#1.0
      L     B [AR1,P#0.0]
      JL    M009
      JU    M00b
      JU    M00a
      JU    M00c
M009: JU    M005
M00b: L     #TEMP3
      T     #TEMP0
      JU    M006
M00a: L     #TEMP3
      T     #TEMP1
      JU    M006
M00c: L     #TEMP3
      T     #TEMP2
      JU    M006
M00e: +AR1  P#1.0
      L     B [AR1,P#0.0]
      T     #TEMP7
      L     P#M 100.0
      LAR2  
      L     #TEMP7
      L     C#8
      *I    
      +AR2  
      TAR2  #TEMP9
      +AR1  P#1.0
      L     B [AR1,P#0.0]
      T     #TEMP8
      L     P#M 100.0
      LAR2  
      L     #TEMP8
      L     C#8
      *I    
      +AR2  
      TAR2  #TEMP10
      TAR1  #TEMP4
      LAR1  #TEMP9
      LAR2  #TEMP10
      L     B [AR1,P#0.0]
      L     B [AR2,P#0.0]
      AW    
      INVI  
      T     #TEMP12
      L     B [AR1,P#0.0]
      L     B [AR2,P#0.0]
      OW    
      L     #TEMP12
      AW    
      T     B [AR1,P#0.0]
      L     DW#16#0
      T     #TEMP0
      L     MB   101
      T     #TEMP1
      L     MB   102
      T     #TEMP2
      L     #TEMP4
      LAR1  
      JU    M006
M011: +AR1  P#1.0
      L     B [AR1,P#0.0]
      T     #TEMP7
      L     P#M 100.0
      LAR2  
      L     #TEMP7
      L     C#8
      *I    
      +AR2  
      TAR2  #TEMP9
      +AR1  P#1.0
      L     B [AR1,P#0.0]
      T     #TEMP8
      L     P#M 100.0
      LAR2  
      L     #TEMP8
      L     C#8
      *I    
      +AR2  
      TAR2  #TEMP10
      TAR1  #TEMP4
      LAR1  #TEMP9
      LAR2  #TEMP10
      L     B [AR1,P#0.0]
      L     B [AR2,P#0.0]
      -I    
      T     B [AR1,P#0.0]
      L     DW#16#0
      T     #TEMP0
      L     MB   101
      T     #TEMP1
      L     MB   102
      T     #TEMP2
      L     #TEMP4
      LAR1  
      JU    M006
M012: L     #TEMP15
      INC   1
      T     #TEMP15
      +AR1  P#1.0
      L     B [AR1,P#0.0]
      T     #TEMP7
      L     P#M 100.0
      LAR2  
      L     #TEMP7
      L     C#8
      *I    
      +AR2  
      TAR2  #TEMP9
      +AR1  P#1.0
      L     B [AR1,P#0.0]
      T     #TEMP8
      L     P#M 100.0
      LAR2  
      L     #TEMP8
      L     C#8
      *I    
      +AR2  
      TAR2  #TEMP10
      TAR1  #TEMP4
      LAR1  #TEMP9
      LAR2  #TEMP10
      L     B [AR1,P#0.0]
      L     B [AR2,P#0.0]
      ==I   
      JCN   M013
      JU    M014
M013: L     P#DBX 0.0
      LAR1  
      T     #TEMP4
      L     B#16#0
      T     #TEMP6
      JU    M006
M014: L     #TEMP4
      LAR1  
      L     #TEMP13
      L     L#1
      +I    
      T     #TEMP13
      JU    M006
M006: L     #TEMP0
      T     MB   100
      L     #TEMP1
      T     MB   101
      L     #TEMP2
      T     MB   102
      +AR1  P#1.0
      L     #TEMP6
      +     1
      T     #TEMP6
      JU    M005
M010: L     P#DBX 0.0
      LAR1  
      L     0
      T     #TEMP6
      TAR1  #TEMP4
M005: TAR1  #TEMP4
      CLR   
      =     #TEMP16
      L     #TEMP13
      L     L#20
      ==I   
      S     #TEMP16
      L     #TEMP15
      ==I   
      A     #TEMP16
      JC    M017
      L     #TEMP13
      L     L#20
      <I    
      S     #TEMP16
      L     #TEMP15
      ==I   
      A     #TEMP16
      JC    M018
      JU    M019
M017: SET   
      =     #TEMP14
      JU    M016
M018: CLR   
      =     #TEMP14
      JU    M016
M019: CLR   
      O     #TEMP14
      =     #RET_VAL
      JU    M015
M016: CLR   
      O     #TEMP14
      =     #RET_VAL

Kodena rada panjang sareng sigana pajeulit pikeun anu teu wawuh sareng STL. Teu aya gunana pikeun nganalisis unggal instruksi dina kerangka tulisan ieu; parentah lengkep sareng kamampuan basa STL tiasa dipendakan dina manual anu saluyu: Daptar pernyataan (STL) pikeun S7-300 jeung S7-400 Programming. Di dieu kuring baris nampilkeun kodeu sarua sanggeus ngolah - renaming labél jeung variabel sarta nambahkeun komentar ngajéntrékeun algoritma operasi sarta sababaraha constructs basa STL. Hayu atuh geuwat dicatet yén blok dimaksud ngandung mesin virtual nu executes sababaraha bytecode lokasina di blok DB100, eusi nu urang terang. Parentah mesin virtual diwangun ku 1 bait kode operasi sareng bait argumen, hiji bait pikeun tiap argumen. Sadaya parentah anu dianggap gaduh dua argumen; Kuring nunjuk nilaina dina koméntar salaku X sareng Y.

Kode sanggeus ngolah]

# Инициализация различных переменных
      L     B#16#0
      T     #CHECK_N        # Счетчик успешно пройденных проверок
      T     #COUNTER_N      # Счетчик общего количества проверок
      L     P#DBX 0.0
      T     #POINTER        # Указатель на текущую инструкцию
      CLR   
      =     #PRE_RET_VAL

# Основной цикл работы интерпретатора байт-кода
LOOP: L     #POINTER
      LAR1  
      OPN   DB   100
      L     DBLG
      TAR1  
      <=D                   # Проверка выхода указателя за пределы программы
      JC    FINISH
      L     DW#16#0
      T     #REG0
      L     #TEMP6
      L     W#16#0
      <>I   
      JC    M00d
      L     P#DBX 0.0
      LAR1  

# Конструкция switch - case для обработки различных опкодов
M00d: L     B [AR1,P#0.0]
      T     #OPCODE
      L     W#16#1
      ==I   
      JC    OPCODE_1
      L     #OPCODE
      L     W#16#2
      ==I   
      JC    OPCODE_2
      L     #OPCODE
      L     W#16#3
      ==I   
      JC    OPCODE_3
      L     #OPCODE
      L     W#16#4
      ==I   
      JC    OPCODE_4
      L     #OPCODE
      L     W#16#5
      ==I   
      JC    OPCODE_5
      L     #OPCODE
      L     W#16#6
      ==I   
      JC    OPCODE_6
      JU    OPCODE_OTHER

# Обработчик опкода 01: загрузка значения из DB101[X] в регистр Y
# OP01(X, Y): REG[Y] = DB101[X]
OPCODE_1: +AR1  P#1.0
      L     P#DBX 0.0
      LAR2  
      L     B [AR1,P#0.0]   # Загрузка аргумента X (индекс в DB101)
      L     C#8
      *I    
      +AR2  
      +AR1  P#1.0
      L     B [AR1,P#0.0]   # Загрузка аргумента Y (индекс регистра)
      JL    M003            # Аналог switch - case на основе значения Y
      JU    M001            # для выбора необходимого регистра для записи.
      JU    M002            # Подобные конструкции используются и в других
      JU    M004            # операциях ниже для аналогичных целей
M003: JU    LOOPEND
M001: OPN   DB   101
      L     B [AR2,P#0.0]
      T     #REG0           # Запись значения DB101[X] в REG[0]
      JU    PRE_LOOPEND
M002: OPN   DB   101
      L     B [AR2,P#0.0]
      T     #REG1           # Запись значения DB101[X] в REG[1]
      JU    PRE_LOOPEND
M004: OPN   DB   101
      L     B [AR2,P#0.0]
      T     #REG2           # Запись значения DB101[X] в REG[2]
      JU    PRE_LOOPEND

# Обработчик опкода 02: загрузка значения X в регистр Y
# OP02(X, Y): REG[Y] = X
OPCODE_2: +AR1  P#1.0
      L     B [AR1,P#0.0]
      T     #TEMP3
      +AR1  P#1.0
      L     B [AR1,P#0.0]
      JL    M009
      JU    M00b
      JU    M00a
      JU    M00c
M009: JU    LOOPEND
M00b: L     #TEMP3
      T     #REG0
      JU    PRE_LOOPEND
M00a: L     #TEMP3
      T     #REG1
      JU    PRE_LOOPEND
M00c: L     #TEMP3
      T     #REG2
      JU    PRE_LOOPEND

# Опкод 03 не используется в программе, поэтому пропустим его
...

# Обработчик опкода 04: сравнение регистров X и Y
# OP04(X, Y): REG[0] = 0; REG[X] = (REG[X] == REG[Y])
OPCODE_4: +AR1  P#1.0
      L     B [AR1,P#0.0]
      T     #TEMP7          # первый аргумент - X
      L     P#M 100.0
      LAR2  
      L     #TEMP7
      L     C#8
      *I    
      +AR2  
      TAR2  #TEMP9          # REG[X]
      +AR1  P#1.0
      L     B [AR1,P#0.0]
      T     #TEMP8
      L     P#M 100.0
      LAR2  
      L     #TEMP8
      L     C#8
      *I    
      +AR2  
      TAR2  #TEMP10         # REG[Y]
      TAR1  #POINTER
      LAR1  #TEMP9          # REG[X]
      LAR2  #TEMP10         # REG[Y]
      L     B [AR1,P#0.0]
      L     B [AR2,P#0.0]
      AW    
      INVI  
      T     #TEMP12         # ~(REG[Y] & REG[X])
      L     B [AR1,P#0.0]
      L     B [AR2,P#0.0]
      OW    
      L     #TEMP12
      AW                    # (~(REG[Y] & REG[X])) & (REG[Y] | REG[X]) - аналог проверки на равенство
      T     B [AR1,P#0.0]
      L     DW#16#0
      T     #REG0
      L     MB   101
      T     #REG1
      L     MB   102
      T     #REG2
      L     #POINTER
      LAR1  
      JU    PRE_LOOPEND

# Обработчик опкода 05: вычитание регистра Y из X
# OP05(X, Y): REG[0] = 0; REG[X] = REG[X] - REG[Y]
OPCODE_5: +AR1  P#1.0
      L     B [AR1,P#0.0]
      T     #TEMP7
      L     P#M 100.0
      LAR2  
      L     #TEMP7
      L     C#8
      *I    
      +AR2  
      TAR2  #TEMP9          # REG[X]
      +AR1  P#1.0
      L     B [AR1,P#0.0]
      T     #TEMP8
      L     P#M 100.0
      LAR2  
      L     #TEMP8
      L     C#8
      *I    
      +AR2  
      TAR2  #TEMP10         # REG[Y]
      TAR1  #POINTER
      LAR1  #TEMP9
      LAR2  #TEMP10
      L     B [AR1,P#0.0]
      L     B [AR2,P#0.0]
      -I                    # ACCU1 = ACCU2 - ACCU1, REG[X] - REG[Y]
      T     B [AR1,P#0.0]
      L     DW#16#0
      T     #REG0
      L     MB   101
      T     #REG1
      L     MB   102
      T     #REG2
      L     #POINTER
      LAR1  
      JU    PRE_LOOPEND

# Обработчик опкода 06: инкремент #CHECK_N при равенстве регистров X и Y
# OP06(X, Y): #CHECK_N += (1 if REG[X] == REG[Y] else 0)
OPCODE_6: L     #COUNTER_N
      INC   1
      T     #COUNTER_N
      +AR1  P#1.0
      L     B [AR1,P#0.0]
      T     #TEMP7          #  REG[X]     
      L     P#M 100.0
      LAR2  
      L     #TEMP7
      L     C#8
      *I    
      +AR2  
      TAR2  #TEMP9          #  REG[X]  
      +AR1  P#1.0
      L     B [AR1,P#0.0]
      T     #TEMP8
      L     P#M 100.0
      LAR2  
      L     #TEMP8
      L     C#8
      *I    
      +AR2  
      TAR2  #TEMP10         # REG[Y]
      TAR1  #POINTER
      LAR1  #TEMP9          # REG[Y]
      LAR2  #TEMP10         # REG[X]
      L     B [AR1,P#0.0]
      L     B [AR2,P#0.0]
      ==I   
      JCN   M013
      JU    M014
M013: L     P#DBX 0.0
      LAR1  
      T     #POINTER
      L     B#16#0
      T     #TEMP6
      JU    PRE_LOOPEND
M014: L     #POINTER
      LAR1  
# Инкремент значения #CHECK_N
      L     #CHECK_N
      L     L#1
      +I    
      T     #CHECK_N
      JU    PRE_LOOPEND

PRE_LOOPEND: L     #REG0
      T     MB   100
      L     #REG1
      T     MB   101
      L     #REG2
      T     MB   102
      +AR1  P#1.0
      L     #TEMP6
      +     1
      T     #TEMP6
      JU    LOOPEND

OPCODE_OTHER: L     P#DBX 0.0
      LAR1  
      L     0
      T     #TEMP6
      TAR1  #POINTER

LOOPEND: TAR1  #POINTER
      CLR   
      =     #TEMP16
      L     #CHECK_N
      L     L#20
      ==I   
      S     #TEMP16
      L     #COUNTER_N
      ==I   
      A     #TEMP16
# Все проверки пройдены, если #CHECK_N == #COUNTER_N == 20
      JC    GOOD
      L     #CHECK_N
      L     L#20
      <I    
      S     #TEMP16
      L     #COUNTER_N
      ==I   
      A     #TEMP16
      JC    FAIL
      JU    M019
GOOD: SET   
      =     #PRE_RET_VAL
      JU    FINISH
FAIL: CLR   
      =     #PRE_RET_VAL
      JU    FINISH
M019: CLR   
      O     #PRE_RET_VAL
      =     #RET_VAL
      JU    LOOP
FINISH: CLR   
      O     #PRE_RET_VAL
      =     #RET_VAL

Saatos gaduh ide ngeunaan paréntah mesin virtual, hayu urang nyerat disassembler leutik pikeun nga-parse bytecode dina blok DB100:

import string
alph = string.ascii_letters + string.digits

with open('DB100.bin', 'rb') as f:
    m = f.read()

pc = 0

while pc < len(m):
    op = m[pc]
    if op == 1:
        print('R{} = DB101[{}]'.format(m[pc + 2], m[pc + 1]))
        pc += 3
    elif op == 2:
        c = chr(m[pc + 1])
        c = c if c in alph else '?'
        print('R{} = {:02x} ({})'.format(m[pc + 2], m[pc + 1], c))
        pc += 3
    elif op == 4:
        print('R0 = 0; R{} = (R{} == R{})'.format(
            m[pc + 1], m[pc + 1], m[pc + 2]))
        pc += 3
    elif op == 5:
        print('R0 = 0; R{} = R{} - R{}'.format(
            m[pc + 1], m[pc + 1], m[pc + 2]))
        pc += 3
    elif op == 6:
        print('CHECK (R{} == R{})n'.format(
            m[pc + 1], m[pc + 2]))
        pc += 3
    else:
        print('unk opcode {}'.format(op))
        break

Hasilna, urang nampi kodeu mesin virtual ieu:

Kode mesin virtual

R1 = DB101[0]
R2 = 6e (n)
R0 = 0; R1 = (R1 == R2)
CHECK (R1 == R0)

R1 = DB101[1]
R2 = 10 (?)
R0 = 0; R1 = R1 - R2
R2 = 20 (?)
R0 = 0; R1 = R1 - R2
CHECK (R1 == R0)

R1 = DB101[2]
R2 = 77 (w)
R0 = 0; R1 = (R1 == R2)
CHECK (R1 == R0)

R1 = DB101[3]
R2 = 0a (?)
R0 = 0; R1 = R1 - R2
R2 = 16 (?)
R0 = 0; R1 = R1 - R2
CHECK (R1 == R0)

R1 = DB101[4]
R2 = 75 (u)
R0 = 0; R1 = (R1 == R2)
CHECK (R1 == R0)

R1 = DB101[5]
R2 = 0a (?)
R0 = 0; R1 = R1 - R2
R2 = 16 (?)
R0 = 0; R1 = R1 - R2
CHECK (R1 == R0)

R1 = DB101[6]
R2 = 34 (4)
R0 = 0; R1 = (R1 == R2)
CHECK (R1 == R0)

R1 = DB101[7]
R2 = 26 (?)
R0 = 0; R1 = R1 - R2
R2 = 4c (L)
R0 = 0; R1 = R1 - R2
CHECK (R1 == R0)

R1 = DB101[8]
R2 = 33 (3)
R0 = 0; R1 = (R1 == R2)
CHECK (R1 == R0)

R1 = DB101[9]
R2 = 0a (?)
R0 = 0; R1 = R1 - R2
R2 = 16 (?)
R0 = 0; R1 = R1 - R2
CHECK (R1 == R0)

R1 = DB101[10]
R2 = 37 (7)
R0 = 0; R1 = (R1 == R2)
CHECK (R1 == R0)

R1 = DB101[11]
R2 = 22 (?)
R0 = 0; R1 = R1 - R2
R2 = 46 (F)
R0 = 0; R1 = R1 - R2
CHECK (R1 == R0)

R1 = DB101[12]
R2 = 33 (3)
R0 = 0; R1 = (R1 == R2)
CHECK (R1 == R0)

R1 = DB101[13]
R2 = 0a (?)
R0 = 0; R1 = R1 - R2
R2 = 16 (?)
R0 = 0; R1 = R1 - R2
CHECK (R1 == R0)

R1 = DB101[14]
R2 = 6d (m)
R0 = 0; R1 = (R1 == R2)
CHECK (R1 == R0)

R1 = DB101[15]
R2 = 11 (?)
R0 = 0; R1 = R1 - R2
R2 = 23 (?)
R0 = 0; R1 = R1 - R2
CHECK (R1 == R0)

R1 = DB101[16]
R2 = 35 (5)
R0 = 0; R1 = (R1 == R2)
CHECK (R1 == R0)

R1 = DB101[17]
R2 = 12 (?)
R0 = 0; R1 = R1 - R2
R2 = 25 (?)
R0 = 0; R1 = R1 - R2
CHECK (R1 == R0)

R1 = DB101[18]
R2 = 33 (3)
R0 = 0; R1 = (R1 == R2)
CHECK (R1 == R0)

R1 = DB101[19]
R2 = 26 (?)
R0 = 0; R1 = R1 - R2
R2 = 4c (L)
R0 = 0; R1 = R1 - R2
CHECK (R1 == R0)

Sakumaha anjeun tiasa tingali, program ieu ngan ukur mariksa unggal karakter tina DB101 pikeun sami sareng nilai anu tangtu. Garis ahir pikeun lulus sadaya cék nyaéta: n0w u 4r3 7h3 m4573r. Upami jalur ieu disimpen dina blok DB101, maka kontrol PLC manual diaktipkeun sareng bakal tiasa ngabeledug atanapi kempis balon.


Éta hungkul! Alexey nunjukkeun tingkat tinggi pangaweruh pantes hiji ninja industri :) Urang dikirim hadiah memorable ka juara. Hatur nuhun ka sadaya pamilon!

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