21 lines
1018 B
Markdown
21 lines
1018 B
Markdown
## Difficulty
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easy - 200/500 punten
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(met een tool als ghidra is dit echt geen werk)
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## How To Solve
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When you decompile the file with something like ghidra (or gdb if you are feeling naughty), you can see that the main
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function passes another function called *app_start* to some GTK functions.
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On closer inspection of this *app_start* function you can see it first checks to see if a keystore file is found and if it
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is it loads that file and tries to check and see if the loaded key is valid with *check_is_key_valid*. If no file was found
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it shows the popup via *build_license_key_popup*, in which it again uses the *check_is_key_valid* function.
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When looking at *check_is_key_valid* you can clearly see the format of the key has to be SHTP-AAAA-BBBB-CCCC.
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Where AAAA and BBBB are hex numbers that have to be larger than 256. On top of that AAAA ^ BBBB has to equal CCCC.
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Now you have enough information to generate your own keys. For example:
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"SHTP-0500-0500-0000"
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## Flag
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IGCTF{Wh0_n33d5_RSA_wh3N_W3_h4v3_XOR}
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