cscg24-rev2

commit 8c74e2304e7757526b96238c7e4e0ee9f39e6011
Author: Louis Burda <quent.burda@gmail.com>
Date:   Sat, 30 Mar 2024 16:03:39 +0100

Add solve

Diffstat:
A
chall/intro-rev-2.zip
 | 
0

A
solve/Dockerfile
 | 
18
++++++++++++++++++
A
solve/flag.txt
 | 
1
+
A
solve/passwd
 | 
1
+
A
solve/rev2
 | 
0

A
solve/solve.py
 | 
5
+++++

6 files changed, 25 insertions(+), 0 deletions(-)
diff --git a/chall/intro-rev-2.zip b/chall/intro-rev-2.zip
Binary files differ.
diff --git a/solve/Dockerfile b/solve/Dockerfile
@@ -0,0 +1,18 @@
+# run via docker compose :)
+
+FROM ubuntu:22.04
+
+RUN apt-get update
+
+RUN apt-get -y install socat 
+
+RUN useradd -d /home/ctf/ -m -p ctf -s /bin/bash ctf
+RUN echo "ctf:ctf" | chpasswd
+
+WORKDIR /home/ctf
+
+COPY rev2 .
+COPY flag.txt .
+
+USER ctf
+CMD socat -ddd TCP4-LISTEN:1024,fork,reuseaddr exec:./rev2,pty,echo=0,raw,iexten=0
diff --git a/solve/flag.txt b/solve/flag.txt
@@ -0,0 +1 @@
+CSCG{y0u_just_r3versed_a_st4tic_transformation!}
diff --git a/solve/passwd b/solve/passwd
@@ -0,0 +1 @@
+yay_st4tic_transf0rmation
diff --git a/solve/rev2 b/solve/rev2
Binary files differ.
diff --git a/solve/solve.py b/solve/solve.py
@@ -0,0 +1,5 @@
+enc = bytes.fromhex("02ea02e8fcfdbdfdf2ece8fdfbeaf7fcefb9fbf6eafdf2f8f700")
+dec = []
+for c in enc:
+    dec.append((c + 0x77) % 0x100)
+print(bytes(dec))