Data Encoding and Hash Challenges Thomas Shaw Single system basic crypto CTF challenge. Single user account with automatic root login to a desktop system. Automatic installation of handy_cli_utilities, hash_tools, hashcat and john the ripper. ctf crypto-ctf easy system 172.16.0.12 13 6 6 6 6 3 true 6 6 999 true false hash_flags hash_flags hash_flags hash_flags hash_flags For this challenge you will need to wrap the hashed word within the braces in the format 'flag{}' before submitting to Hacktivity. Some inputs to the hash functions have been salted, when submitting the flag please omit the salt within your 'flag{}' string. Examples: Input asdf to md5 [challenger@localhost ~]$ echo "asdf" | md5sum 2b00042f7481c7b056c4b410d28f33cf - Input asdf with an appended random salt of 1234 to md5sum(asdf1234) [challenger@localhost ~]$ echo "asdf1234" | md5sum 622d1280547ccb5b88e05a6540665ca0 - Input asdf with a prepended random salt of 1234 to md5sum(1234asdf) [challenger@localhost ~]$ echo "1234asdf" | md5sum 885ac5cfada75f388bd79f3615d3f9c8 - The expected flag for all of the above is: flag{asdf} Hint: This challenge applied a weak numerical salt to the string before it was fed into the hash function (between 000-999). A flag has been encoded with a simple encoding method that you may be able to reverse to reveal the flag. challenger tiaspbiqe2r true Welcome! This scenario involves solving a series of crypto / encoding / hash based challenges to find flags. The challenges can be found in the /home/challenger/challenges/ directory. The password for the challenger account is: tiaspbiqe2r Tools provided that you may find useful: hashcat, john the ripper `sudo john` `hashcat` Any flags you find whilst solving challenges should be submitted to Hacktivity to claim your points. Good luck and have fun! instructions.txt challenges cipher challenges/challenge_01 simple_encoding hint challenges/challenge_01 challenges cipher challenges/challenge_02 simple_encoding hints challenges/challenge_02 challenges/challenge_03 challenges cipher challenges/challenge_04 challenges/challenge_05 challenges hash challenges/challenge_06 hash_instructions hint challenges/challenge_06 challenges hash challenges/challenge_07 hash_instructions hint challenges/challenge_07 challenges hash challenges/challenge_08 hash_instructions hint challenges/challenge_08 challenges hash challenges/challenge_09 hash_instructions hash_instructions hint challenges/challenge_09 challenges hash challenges/challenge_10 hash_instructions hash_instructions hash_instructions hint challenges/challenge_10 accounts true /home/challenger/instructions.txt accounts true accounts IP_addresses