c3

c3/sol.py

@@ -0,0 +1,19 @@
+#!/home/maxime/.pyvenv/bin/python3
+from pwn import *
+
+lookup1 = "\n \"#()*+/1:=[]abcdefghijklmnopqrstuvwxyz"
+lookup2 = "ABCDEFGHIJKLMNOPQRSTabcdefghijklmnopqrst"
+
+with open("ciphertext", 'r') as f:
+    ciphertext = f.read()
+
+out = ""
+prev = 0
+for char in ciphertext:
+    pos = lookup2.index(char)
+    out += lookup1[(pos+prev)%40]
+    prev = (pos+prev)%40
+
+print(out)
+
+