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SECCON CTF 13 決勝観戦CTF

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TopChallengesScoreboardWriteups

Welcome!
100 pts (167 solves)
Welcome
Beginner

Author:

minaminao

Long Flag
100 pts (152 solves)
Crypto
Beginner

Author:

🍪
100 pts (139 solves)
Web
Beginner

Author:

Beginner's Flag Printer
100 pts (121 solves)
Rev
Beginner

Author:

parseInt
100 pts (89 solves)
Misc
Beginner

Author:

trippple
100 pts (81 solves)
Crypto

Author:

danger of buffer overflow
100 pts (78 solves)
Pwn

Author:

play with memory
100 pts (75 solves)
Pwn

Author:

42
100 pts (40 solves)
Crypto

Author:

Flag Printer
100 pts (38 solves)
Rev

Author:

Can U Keep A Secret?
100 pts (31 solves)
Pwn
Beginner

Author:

cache crasher
100 pts (21 solves)
Pwn

Author:

1linepyjail4b
100 pts (19 solves)
Misc

Author:

csv2json
100 pts (15 solves)
Web

Author:

Customizable EC
100 pts (11 solves)
Crypto

Author:

42*
100 pts (10 solves)
Crypto

Author:

Slow Flag Printer
100 pts (10 solves)
Rev

Author:

dinosaur
100 pts (8 solves)
Web

Author:

Alpaca Wakekko
100 pts (6 solves)
Pwn

Author:

blue-note
100 pts (6 solves)
Web

Author:

Concurrent Flag Printer
100 pts (3 solves)
Rev

Author:

42

100 pts (40 solves)
Crypto

Author:

minaminao

出力からフラグを復元してください🐍

import os
from Crypto.Util.number import getPrime, bytes_to_long

x = bytes_to_long(os.getenv("FLAG").encode())
for _ in range(42):
    x *= getPrime(42)
print(x)

出力:

1147519914005635970823022779519580521609222940350823007699842537827644738629829657046897975782350987748029018405699017377382521676899556171556649128260865812262043303782475632488849236816194782530154901066736272457909268699844626557409460652217501658644287801649083260640392194864370700199619482572398308537257922259125395585581757757644945754520977388691814074631081409677094992839775104691433743609551833747629636402523522392312458111656977789142053773849669780021688811768524291886161405435708715493344047580746854894532523408006689911316576153711061177239836663374119954672786387
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