WIP Insomni'hack

insomnihack24/mobile/passphrase_break.py

@@ -0,0 +1,33 @@
+from Crypto.Cipher import AES
+from Crypto.Util.Padding import pad
+import base64
+
+key = b'A'*32  # Unknown 32-byte key
+encrypted_flag = base64.decodebytes(b"uS0D11dq3RM9QimRWfXcewwQdoxYwrZRNUGT205pDfQ=")
+
+def encrypt(plaintext, flag):
+    padded = pad(plaintext + flag, 32)
+    cipher = AES.new(key, AES.MODE_ECB)
+
+    ciphertext = cipher.encrypt(padded)
+    return ciphertext.hex()
+
+
+def bruteforce():
+    flag = ''
+    total = 64 - 1
+    chars = 'abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789_-~!?#%&@{}'
+
+    while True:
+        payload = '1' * (total - len(flag))
+        ciphertext_1 = encrypt((payload+flag).encode())
+
+        for c in chars:
+            ciphertext_2 = encrypt((payload + flag + c).encode())
+            # Comapare the middle blocks ([32:64]) of each encrypted text
+            if ciphertext_2[64:128] == ciphertext_1[64:128]:
+                flag += c
+            print(flag)
+            break
+        
+bruteforce()