Writeup: FlareOn 2021: 003 - antioch

$ docker load -i antioch.tar

$ docker run -v /var/run/docker.sock:/var/run/docker.sock mrhavens/dedockify a1
FROM antioch:latest
ADD file:fae1674275a5cc9b0c04ef177df65aebeaf796b0ba7c94ac2bd35120306411d4 in /
CMD ["/AntiochOS"]

$ unar antioch.tar
$ cd ./antioch/
find ./ -type f -name *.tar -exec tar -xf {} \;

remnux@remnux:~/RE$ docker run -i antioch /AntiochOS
AntiochOS, version 1.32 (build 1975)
Type help for help
> approach
Approach the Gorge of Eternal Peril!
What is your name? Sir Lancelot
What is your quest? To seek the Holy Grail
What is your favorite color? Blue
Right. Off you go. #18

> approach
Approach the Gorge of Eternal Peril!
What is your name? Sir Gallahad
What is your quest? To seek the Holy Grail!
What is your favorite color? Yellow
Right. Off you go. #30

#!/usr/bin/env python3

from pprint import pprint

known_crc32 = [0x0B59395A9,0x1BB5AB29,0x0E,0x5EFDD04B,0x3F8468C8,0x12,0x0ECED85D0,0x82D23D48,0x2,0x0D8549214,0x472EE5,0x1D,0x2C2F024D,0x0C9A060AA,0x0C,0x18A5232,0x24D235,0x0D,0x72B88A33,0x81576613,0x14,0x674404E2,0x5169E129,0x0B,0x307A73B5,0x0E560E13E,0x1C,0x13468704,0x2358E4A9,0x15,0x94F6471B,0x0D6341A53,0x5,0x0EDA1CF75,0x0BAFA91E5,0x18,0x0BBAC124D,0x0A697641D,0x19,0x0F707E4C3,0x0EF185643,0x7,0x0D702596F,0x79C28915,0x0A,0x86A10848,0x59108FDC,0x1,0x0D640531C,0x0EF3DE1E8,0x13,0x7B665DB3,0x0A3A903B0,0x3,0x0AB1321CC,0x0EEEDEAD7,0x4,0x4F6066D8,0x9C8A3D07,0x11,0x256047CA,0x4085BE9E,0x9,0x3FC91ED3,0x379549C9,0x8,0x0A424AFE4,0x0EF871347,0x1B,0x550901DA,0x1FCEC6B,0x10,0x10A29E2D,0x0E76056AA,0x16,0x56CBC85F,0x356F1A68,0x0F,0x80DFE3A6,0x9D0AB536,0x1E,0x0E657D4E1,0x0B4E9FD30,0x17,0x2BA1E1D4,0x0BE66D918,0x1A,0x7D33089B,0x67C1F585,0x6,]

import zlib

known_crc32_length = len(known_crc32)/3
print(f"{known_crc32_length}")

names = [ "Dragon of Angnor", "Roger the Shrubber", "Dinky", "Dennis the Peasant", "Sir Ector", "A Famous Historian", "Tim the Enchanter", "Sir Gawain", "Trojan Rabbit", "Sir Robin", "Green Knight", "Sir Bedevere", "Squire Concorde", "Sir Not-Appearing-in-this-Film", "Legendary Black Beast of Argh", "Sir Gallahad", "Lady of the Lake", "Zoot", "Miss Islington", "Chicken of Bristol", "Rabbit of Caerbannog", "Black Knight", "Prince Herbert", "Brother Maynard", "King Arthur", "Sir Bors", "Squire Patsy", "Bridge Keeper", "Inspector End Of Film", "Sir Lancelot"] 

tuples = []

for name in names:
    crc32_value = zlib.crc32((name+'\n').encode('ascii')) & 0xffffffff
    for i in range(0,int(known_crc32_length)):
        if crc32_value == known_crc32[i*3]:
            tuples.append((name, known_crc32[i*3+2]))
            break

sorted_by_second = sorted(tuples, key=lambda tup: tup[1])
pprint(sorted_by_second)

[('Miss Islington', 1),
 ('Sir Bors', 2),
 ('Tim the Enchanter', 3),
 ('Dragon of Angnor', 4),
 ('Brother Maynard', 5),
 ('Sir Bedevere', 6),
 ('Sir Robin', 7),
 ('Zoot', 8),
 ('Squire Concorde', 9),
 ('Green Knight', 10),
 ('Trojan Rabbit', 11),
 ('Chicken of Bristol', 12),
 ('Roger the Shrubber', 13),
 ('Bridge Keeper', 14),
 ('Sir Gawain', 15),
 ('Legendary Black Beast of Argh', 16),
 ('A Famous Historian', 17),
 ('Sir Lancelot', 18),
 ('Lady of the Lake', 19),
 ('Rabbit of Caerbannog', 20),
 ('Sir Not-Appearing-in-this-Film', 21),
 ('Prince Herbert', 22),
 ('King Arthur', 23),
 ('Inspector End Of Film', 24),
 ('Sir Ector', 25),
 ('Squire Patsy', 26),
 ('Dennis the Peasant', 27),
 ('Dinky', 28),
 ('Black Knight', 29),
 ('Sir Gallahad', 30)]

rm -rf ./repacked

names=(
    'Islington'
    'Bors'
    'Enchanter'
    'Dragon'
    'Brother'
    'Bedevere'
    'Robin'
    'Zoot'
    'Squire'
    'Green'
    'Trojan'
    'Chicken'
    'Shrubber'
    'Bridge'
    'Gawain'
    'Legendary'
    'Famous'
    'Lancelot'
    'Lady'
    'Rabbit'
    'Not-Appearing-in-this-Film'
    'Herbert'
    'Arthur'
    'Inspector'
    'Ector'
    'Squire'
    'Dennis'
    'Dinky'
    'Black'
    'Gallahad'
)

for name in ${names[*]}
do
    printf "NAME %s\n" $name
    layer=$(grep -r $name ./antioch)
    path=${layer:0:75}layer.tar
    printf "%s\n" $path
    unar -f -D -o ./repacked $path
    #sleep 2
    #exit
done

unar -f -D -o ./repacked ./antioch/7016b68f19aed3bb67ac4bf310defd3f7e0f7dd3ce544177c506d795f0b2acf3/layer.tar