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A cikin sawun Ninja Masana'antu: yadda aka yi kutse a PLC a Kwanakin Hack Mai Kyau 9

A cikin sawun Ninja Masana'antu: yadda aka yi kutse a PLC a Kwanakin Hack Mai Kyau 9

A PHDays 9 na ƙarshe mun gudanar da gasar haƙƙin masana'antar sarrafa iskar gas - gasar Ninja masana'antu. Akwai tsayayye guda uku akan rukunin yanar gizon tare da sigogin tsaro daban-daban (Babu Tsaro, Tsaro mara ƙarfi, Babban Tsaro), suna yin koyi da tsarin masana'antu iri ɗaya: an jefa iska ƙarƙashin matsin lamba a cikin balloon (sannan kuma a sake shi).

Duk da ma'auni na aminci daban-daban, kayan aikin kayan aiki na tsaye ya kasance iri ɗaya: Siemens Simatic PLC S7-300 series; maɓallin deflation na gaggawa da na'urar auna matsi (wanda aka haɗa zuwa PLC dijital bayanai (DI)); bawuloli masu aiki don hauhawar farashin kaya da lalata iska (wanda aka haɗa da abubuwan dijital na PLC (DO)) - duba hoton da ke ƙasa.

A cikin sawun Ninja Masana'antu: yadda aka yi kutse a PLC a Kwanakin Hack Mai Kyau 9

PLC, dangane da karatun matsa lamba kuma daidai da shirinta, ya yanke shawarar yankewa ko kunna ƙwallon (buɗe da rufe bawuloli masu dacewa). Koyaya, duk tashoshi suna da yanayin kulawa da hannu, wanda ya ba da damar sarrafa jihohin bawuloli ba tare da wani hani ba.

Matsakaicin sun bambanta a cikin sarƙaƙƙiyar ba da damar wannan yanayin: a wurin da ba shi da kariya ya fi sauƙi don yin hakan, kuma a Babban Tsaro ya fi wahala daidai.

An magance biyar daga cikin matsalolin shida a cikin kwanaki biyu; Mahalarta wuri na farko ya sami maki 233 (ya shafe mako guda yana shirye-shiryen gasar). Masu nasara uku: Na sanya - a1exdandy, II - Rubikoid, III - Ze.

Duk da haka, a lokacin PHDays, babu daya daga cikin mahalarta da ya iya shawo kan dukkan matakan uku, don haka mun yanke shawarar yin gasa ta kan layi kuma mun buga aiki mafi wahala a farkon Yuni. Masu shiga dole ne su kammala aikin a cikin wata guda, su nemo tuta, kuma su bayyana bayani dalla-dalla da kuma hanya mai ban sha'awa.

A ƙasa da yanke mun buga nazarin mafi kyawun mafita ga aikin daga waɗanda aka aika a cikin wata, Alexey Kovrizhnykh (a1exdandy) daga Kamfanin Tsaro na Digital, wanda ya dauki matsayi na XNUMX a gasar a lokacin PHDays. A ƙasa muna gabatar da rubutunsa tare da sharhinmu.

Binciken farko

Don haka, aikin yana ƙunshe da faifai tare da fayiloli masu zuwa:

  • toshe_upload_traffic.pcapng
  • DB100.bin
  • nuni.txt

Fayil na hints.txt ya ƙunshi mahimman bayanai da alamu don warware aikin. Ga abinda ke cikinsa:

  1. Petrovich ya gaya mani jiya cewa zaku iya loda tubalan daga PlcSim zuwa Step7.
  2. An yi amfani da Siemens Simatic S7-300 series PLC a wurin tsayawa.
  3. PlcSim kwaikwayo ne na PLC wanda ke ba ku damar gudanar da gyara shirye-shirye don Siemens S7 PLCs.

Fayil ɗin DB100.bin ya bayyana yana ɗauke da toshe bayanan DB100 PLC: 00000000: 0100 0102 6e02 0401 0206 0100 0101 0102 ....n......... 00000010: 1002 0501. 0202 2002 . ......... 0501: 0206 0100 0102 00000020 0102 7702 0401 0206a0100 ..w............. 0103: 0102 0 02 00000030 0501 0202 ................. 1602: 0501 0206 0100 0104 0102 00000040 7502a0401 0206 u............... 0100 0105..........0102. 0: 02 0501 00000050 0202 1602 0501 0206 0100 .........&..... 0106: 0102c3402 4 00000060 0401 0206 0100 0107 0102 L.........2602. .. 0501 0202 00000070 4 02 0501a0206 0100 0108 0102 ................ 3302: 0401 3 00000080 0206a 0100 0109 0102 0 ........ 02a0501: 0202 1602b 00000090 0501 0206 0100 010 0102 ......".....F... 3702b0401: 0206 7 000000c 0 0100 010 0102 .. 2202c0501: 0202d 4602 0501a000000 0 0206 0100 010 0102 ................ 3302d0401: 0206 0100e 3 000000d0 010 0102 .m. . ..... 0: 02 0501 0202 1602 0501 0206 000000 0 ......%......... 0100: 010 0102 6 02 0401 0206 0100 010 ......&. 000000: 0 0102 1102c0501 0202 2302 0501 ....L......

Kamar yadda sunan ke nunawa, fayil ɗin block_upload_traffic.pcapng yana ƙunshe da juji na toshe hanyoyin lodawa zuwa PLC.

Yana da kyau a lura cewa wannan juji na zirga-zirga a wurin gasar yayin taron ya ɗan ɗan fi wahalar samu. Don yin wannan, ya zama dole don fahimtar rubutun daga fayil ɗin aikin don TeslaSCADA2. Daga gare ta za a iya fahimtar inda juji ɓoyayyen ta amfani da RC4 yake da kuma abin da maɓalli da ake buƙatar amfani da shi don warware shi. Za a iya samun jujjuya bayanan toshewar akan rukunin yanar gizon ta amfani da abokin ciniki na yarjejeniya na S7. Don wannan na yi amfani da abokin ciniki na demo daga fakitin Snap7.

Ciro tubalan sarrafa sigina daga juji na zirga-zirga

Duban abubuwan da ke cikin juji, za ku iya fahimtar cewa ya ƙunshi tubalan sarrafa sigina OB1, FC1, FC2 da FC3:

A cikin sawun Ninja Masana'antu: yadda aka yi kutse a PLC a Kwanakin Hack Mai Kyau 9

Dole ne a cire waɗannan tubalan. Ana iya yin wannan, alal misali, tare da rubutun mai zuwa, tun da a baya canza zirga-zirga daga tsarin pcapng zuwa 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 = ''

Bayan bincika sakamakon tubalan, za ku lura cewa koyaushe suna farawa da bytes 70 70 (pp). Yanzu kuna buƙatar koyon yadda ake yin nazarin su. Alamar aikin tana nuna cewa kuna buƙatar amfani da PlcSim don wannan.

Samun umarnin mutum-mai karantawa daga tubalan

Da farko, bari mu yi ƙoƙarin shirya S7-PlcSim ta hanyar loda tubalan da yawa tare da maimaita umarnin (= Q 0.0) a ciki ta amfani da software na Simatic Manager, da adana PLC da aka samu a cikin kwaikwayi zuwa fayil ɗin example.plc. Ta hanyar kallon abubuwan da ke cikin fayil ɗin, zaku iya tantance farkon tubalan da aka sauke ta sa hannun 70 70, wanda muka gano a baya. Kafin tubalan, a fili, an rubuta girman toshe a matsayin ƙimar ƙaramin-byte 4-endian.

A cikin sawun Ninja Masana'antu: yadda aka yi kutse a PLC a Kwanakin Hack Mai Kyau 9

Bayan mun sami bayanai game da tsarin fayilolin plc, shirin mai zuwa ya bayyana don karanta shirye-shiryen PLC S7:

  1. Yin amfani da Manajan Simatic, muna ƙirƙirar tsarin toshe a cikin S7-PlcSim kama da wanda muka karɓa daga juji. Girman toshe dole ne su dace (ana samun wannan ta hanyar cika tubalan tare da adadin umarnin da ake buƙata) da masu gano su (OB1, FC1, FC2, FC3).
  2. Ajiye PLC zuwa fayil.
  3. Muna maye gurbin abubuwan da ke cikin tubalan a cikin fayil ɗin da aka samu tare da tubalan daga juji na zirga-zirga. An ƙaddara farkon tubalan ta hanyar sa hannu.
  4. Muna loda fayil ɗin da aka samo a cikin S7-PlcSim kuma duba abubuwan da ke cikin tubalan a cikin Simatic Manager.

Ana iya maye gurbin tubalan, alal misali, tare da lambar mai zuwa:

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 ya ɗauki wata ƙila mafi wahala, amma har yanzu madaidaiciyar hanya. Mun ɗauka cewa mahalarta za su yi amfani da shirin NetToPlcSim don PlcSim ya iya sadarwa ta hanyar sadarwar, loda tubalan zuwa PlcSim ta hanyar Snap7, sannan zazzage waɗannan tubalan azaman aiki daga PlcSim ta amfani da yanayin ci gaba.

Ta hanyar buɗe fayil ɗin da aka samo a cikin S7-PlcSim, zaku iya karanta tubalan da aka sake rubutawa ta amfani da Simatic Manager. Ana yin rikodin manyan ayyukan sarrafa na'ura a cikin toshe FC1. Na musamman bayanin kula shine madaidaicin #TEMP0, wanda idan kun kunna shi yana bayyana don saita ikon PLC zuwa yanayin jagora bisa ƙimar ƙwaƙwalwar bit M2.2 da M2.3. An saita ƙimar #TEMP0 ta aikin FC3.

A cikin sawun Ninja Masana'antu: yadda aka yi kutse a PLC a Kwanakin Hack Mai Kyau 9

Don magance matsalar, kuna buƙatar bincika aikin FC3 kuma ku fahimci abin da ake buƙatar yi domin ya dawo da ma'ana.

An tsara tubalan sarrafa siginar PLC a madaidaicin Tsaron Tsaro a wurin gasar ta irin wannan hanya, amma don saita ƙimar canjin #TEMP0, ya isa ya rubuta layin ninja dina a cikin toshe DB1. Duba darajar a cikin toshe ya kasance mai sauƙi kuma baya buƙatar zurfin ilimin toshe shirye-shiryen harshe. A bayyane yake, a matakin Babban Tsaro, samun ikon sarrafa hannu zai zama da wahala sosai kuma yana da mahimmanci a fahimci rikitattun yaren STL (ɗaya daga cikin hanyoyin tsara S7 PLC).

Juya block FC3

Abubuwan da ke cikin toshe FC3 a cikin wakilcin 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

Lambar tana da tsayi sosai kuma tana iya zama kamar rikitarwa ga wanda bai saba da STL ba. Babu ma'ana cikin nazarin kowane umarni a cikin tsarin wannan labarin; ana iya samun cikakkun bayanai da iyawar harshen STL a cikin jagorar da ta dace: Jerin Bayani (STL) don S7-300 da S7-400 Shirye-shiryen. Anan zan gabatar da lambar guda ɗaya bayan sarrafawa - sake suna da lakabi da masu canji da ƙara sharhi da ke kwatanta aikin algorithm da wasu gine-ginen harshen STL. Bari in lura nan da nan cewa toshewar da ake tambaya yana ƙunshe da injin kama-da-wane da ke aiwatar da wasu bytecode da ke cikin DB100 block, abin da muka sani. Umarnin na'ura mai ma'ana ya ƙunshi 1 byte na lambar aiki da bytes na gardama, byte ɗaya ga kowace hujja. Duk umarnin da aka yi la'akari suna da gardama guda biyu; Na sanya ƙimar su a cikin sharhi kamar X da Y.

Code bayan aiki] 

# 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

Bayan samun ra'ayin umarnin injin kama-da-wane, bari mu rubuta ƙaramin disassembler don rarraba bytecode a cikin toshe 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

Sakamakon haka, muna samun lambar injin kama-da-wane mai zuwa:

Virtual inji code

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)

Kamar yadda kake gani, wannan shirin yana duba kowane hali daga DB101 don daidaito zuwa wani ƙima. Layin ƙarshe don wucewa duk cak shine: n0w u 4r3 7h3 m4573r. Idan an sanya wannan layin a cikin toshe DB101, to ana kunna sarrafa PLC na hannu kuma zai yiwu a fashe ko lalata balloon.


Shi ke nan! Alexey ya nuna babban matakin ilimi wanda ya cancanci ninja na masana'antu :) Mun aika da kyaututtukan da ba za a iya mantawa da su ba ga mai nasara. Godiya mai yawa ga duk mahalarta!

source: www.habr.com

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