Overthewire Bandit Level 8 -> 9
Solution for the Overthewire.org Bandit level 8 -> 9
Level Goal
The password for the next level is stored in the file data.txt and is the only line of text that occurs only once.
Walkthrough
Login to the server using the password obtained from the previous level Bandit level 7 -> 8.
username: bandit8
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ssh bandit8@bandit.labs.overthewire.org -p 2220
For this level we need to search all lines of text in the a file and find the single line that is unique (only occurs once) in the file.
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bandit8@bandit:~$ ls
data.txt
bandit8@bandit:~$ cat data.txt
VkBAEWyIibVkeURZV5mowiGg6i3m7Be0
zdd2ctVveROGeiS2WE3TeLZMeL5jL7iM
sYSokIATVvFUKU4sAHTtMarfjlZWWj5i
ySvsTwlMgnUF0n86Fgmn2TNjkSOlrV72
NLWvtQvL7EaqBNx2x4eznRlQONULlCYZ
LfrBHfAh0pP9bgGAZP4QrVkut3pysAYC
U0NYdD3wHZKpfEg9qGQOLJimAJy6qxhS
flyKxCbHB8uLTaIB5LXqQNuJj3yj00eh
TThRArdF2ZEXMO47TIYkyPPLtvzzLcDf
cIPbot7oYveUPNxDMhv1hiri50CqpkTG
*
*
*
iwE0KTeKQ8PWihqvjUnpu52YZeIO8Pqb
qaWWAOOquC3yHnfJI4zvPWzCBdfHQ8wa
0N65ZPpNGkUJePzFxctCRZRXVrCbUGfm
cR6riSWC0ST7ALZ2i1e47r3gc0QxShGo
TKUtQbeYnEzzYIne7BinoBx2bHFLBXzG
8NtHZnWzCA8HswoJSCU7Ojg8nP3eKpsA
SzwgS2ADSjP6ypOzp2bIvdqNyusRtrHj
5AdqWjoJOEdx5tJmZVBMo0K2e4arD3ZW
gqyF9CW3NNIiGW27AtWVNPqp3i1fxTMY
flyKxCbHB8uLTaIB5LXqQNuJj3yj00eh
w4zUWFGTUrAAh8lNkS8gH3WK2zowBEkA
bandit8@bandit:~$
Printing the contents of the file to the screen we can see there is lot of lines of text and each line is made up of one password.
Using wc -l we can see how many lines are in the file.
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bandit8@bandit:~$ wc -l data.txt
1001 data.txt
1001 lines is too much to check manually.
Before we can eliminate the duplicated lines we need to group them together.
sort command can sort the contents of a file and print to screen.
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bandit8@bandit:~$ sort data.txt
07KC3ukwX7kswl8Le9ebb3H3sOoNTsR2
07KC3ukwX7kswl8Le9ebb3H3sOoNTsR2
07KC3ukwX7kswl8Le9ebb3H3sOoNTsR2
07KC3ukwX7kswl8Le9ebb3H3sOoNTsR2
07KC3ukwX7kswl8Le9ebb3H3sOoNTsR2
07KC3ukwX7kswl8Le9ebb3H3sOoNTsR2
07KC3ukwX7kswl8Le9ebb3H3sOoNTsR2
07KC3ukwX7kswl8Le9ebb3H3sOoNTsR2
07KC3ukwX7kswl8Le9ebb3H3sOoNTsR2
07KC3ukwX7kswl8Le9ebb3H3sOoNTsR2
0efnqHY1ZTNRu4LsDX4D73DsxIQq7RuJ
0efnqHY1ZTNRu4LsDX4D73DsxIQq7RuJ
0efnqHY1ZTNRu4LsDX4D73DsxIQq7RuJ
0efnqHY1ZTNRu4LsDX4D73DsxIQq7RuJ
0efnqHY1ZTNRu4LsDX4D73DsxIQq7RuJ
*
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*
Now we have grouped all duplicated lines we can elimiate the doubles.
uniq command will let us eliminated duplicated lines so we only see single occurences of each line.
We sort the data and pipe that to uniq to remove all the doubles.
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bandit8@bandit:~$ sort data.txt | uniq
07KC3ukwX7kswl8Le9ebb3H3sOoNTsR2
0efnqHY1ZTNRu4LsDX4D73DsxIQq7RuJ
0N65ZPpNGkUJePzFxctCRZRXVrCbUGfm
0Xo6DLyK5izRqEtBA7sW2SRmlAixWYSg
10XitczY5Dz7UMoseKIeFWSzzwQrylfw
1ETSsKgjfQj1cJeFzXLJWzKzza3iWcJa
1T6qw9I32d71cS3TTvwmVp1WsxPFDJ9I
2bFz9F0yRwxGzVCZ4Er04bk00qfUrzWb
2CxmtCkpNL5ZjuoNzAtShkPXf5T43W7s
337o85y4OymIh99WPUtotkb114evfAkC
33xpPQhjt4Q2mqtX4sCVRwH2Zyh82E8R
4SMqyZZztep75cte6xxKpVL49pKUkV8N
5AdqWjoJOEdx5tJmZVBMo0K2e4arD3ZW
5cO8XuoQWrzsyeOWDht8zgUIVWSRDaeC
6PF22p6O8TphCTZot9ApZx8VfGuo8rd5
*
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*
Eventhough we have removed all doubled lines we still have not narrowed down the search to the one line that is entirely unique.
The man page of uniq shows an option for unique lines.
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Excerpt form the man page of uniq
-u, --unique
only print unique lines
Combining the sort and uniq -u we can get the single line of text in data.txt that is entirely unique.
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bandit8@bandit:~$ sort data.txt | uniq -u
UsvVyF##########################