write-ups-challenges-2020-2021/scheming-schemer/third/README.md
2022-11-24 18:03:20 +01:00

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== Title ==
The Scheming Schemer 3
== Description ==
Just like the previous 2:
<TODO>
== Flag ==
IGCTF{GoodJob!YouFoundThemAll!}
== Files ==
Participants should receive the calculator-app.rkt file.
== Deployment ==
Something something telnet/netcat
== Solution/Writeup ==
The code now allows an arbitrary expression in the first position, so we can create a lambda that will be executed by the interpreter.
Example input to print the solution:
((lambda ()
(call-with-input-file
"flag.txt"
(lambda (input-port)
(let loop ((x (read-char input-port)))
(if (not (eof-object? x))
(begin
(display x)
(loop (read-char input-port)))))))))