PicoCTF - Operation Orchid

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PicoCTF - Operation Orchid

Recon

這一題過於簡單

Exploit - Forensics / Openssl

  1. Find Encryption Flag File(Autopsy) 可以在/root中找到，然後.ash_history的command紀錄中知道加密的password phrase 

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     touch flag.txt
 nano flag.txt 
 apk get nano
 apk --help
 apk add nano
 nano flag.txt 
 openssl
 openssl aes256 -salt -in flag.txt -out flag.txt.enc -k unbreakablepassword1234567
 shred -u flag.txt
 ls -al
 halt

  2. Script

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     $ openssl aes-256-cbc -in flag.txt.enc -d
 enter aes-256-cbc decryption password:
 *** WARNING : deprecated key derivation used.
 Using -iter or -pbkdf2 would be better.
 bad decrypt
 140342062343488:error:06065064:digital envelope routines:EVP_DecryptFinal_ex:bad decrypt:crypto/evp/evp_enc.c:612:
 picoCTF{h4un71ng_p457_5113beab}%