CTFs and solutions

guess-mode-double-shot/attack.py

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+#!/usr/bin/env python3
+
+from pwn import *
+
+HOST = "130.192.5.212"
+PORT = "6532"
+
+server = remote(HOST, PORT)
+sleepT = 0.5
+# Different IV when CBC therefore different encryption?
+for i in range(128):
+    print('-'*20)
+    print(server.recv(1024))
+    payload = (b'A'*32).hex()
+    server.send(payload)
+    server.send('\n')
+    sleep(sleepT)
+    enc = server.recv(1024).split(b":")[1].split(b'\n')[0].strip()
+    print(f"Encryption1:{enc}")
+    enc = bytes.fromhex(enc.decode('utf-8'))
+    sleep(sleepT)
+    #payload2 =  bytes([d1 ^ e1 for d1, e1 in zip(b'A'*32, enc)])
+    payload2 = (b'A'*32).hex()
+    #print(payload2)
+
+    #payload2= (b'B'*32).hex()
+    server.send(payload2)
+    server.send('\n')
+    sleep(sleepT)
+    enc2 = server.recv(1024).split(b":")[1].split(b'\n')[0].strip()
+    #print(enc)
+    print(f"Encryption2:{enc2}")
+    enc2 = bytes.fromhex(enc2.decode('utf-8'))
+    sleep(sleepT)
+    if(enc==enc2):
+        print("ECB")
+        server.send(b"ECB")
+        server.send("\n")
+    else:
+        print("CBC")
+        server.send(b"CBC")
+        server.send("\n")
+        sleep(sleepT)
+    #print(server.recv(1024))
+    sleep(sleepT)
+
+print(server.recv(1024))