added default.nix and various ctf examples

examples/cryptohack-ecboracle.py

@@ -0,0 +1,46 @@
+import requests
+
+from imp.constants import PRINTABLE
+from imp.attacks import paddingoracle
+
+from Crypto.Util.Padding import pad
+
+import string
+
+NIBBLESET = [n.to_bytes() for n in range(256)]
+
+HOST = 'https://aes.cryptohack.org'
+ENDPOINT = '/ecb_oracle/encrypt/{0}/'
+URI = HOST + ENDPOINT
+
+CHARSET = [c.encode() for c in string.printable]
+# CHARSET = NIBBLESET # OVERRIDE
+
+FLAG_LEN = 26  # flag length, calculated by hand
+SPACER = b'\x0f' # arbitrary spacing character
+
+BLOCK_BYTES = 16
+BLOCK_NIBBLES = 32 # measured in nibbles
+
+
+def mkreq(hextext: str) -> dict[str, str]:
+    resp = requests.get(URI.format(hextext))
+    if resp.status_code != 200:
+        raise Exception(f'[!] resp failed! {resp} : {resp.text}')
+    return resp.json()
+
+def encrypt(b: bytes) -> bytes:
+    resp = mkreq(b.hex())
+    return bytes.fromhex(resp['ciphertext'])
+
+def main() -> None:
+    paddingoracle.crack(encrypt, pad, CHARSET, 16, batch_size=20, debug=True)
+
+               
+
+if __name__ == '__main__':
+    try:
+        main()
+    except (KeyboardInterrupt, EOFError):
+        print('\n[!] Interrupt')
+

examples/local-ecboracle.py

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+import string
+
+from imp.attacks import paddingoracle
+
+from Crypto.Cipher import AES
+from Crypto.Util.Padding import pad
+
+CHARSET = [c.encode() for c in string.printable]
+
+KEY = b'you wont get me!'
+FLAG = b'imbaud{omg_you_catched_me}'
+CIPHER = AES.new(KEY, AES.MODE_ECB)
+
+def encrypt(b: bytes, debug=False) -> bytes:
+    padded = pad(b + FLAG, 16)
+    if debug:
+        print(padded)
+    # print(padded)
+    return CIPHER.encrypt(padded)
+
+def main() -> None:
+    paddingoracle.crack(encrypt, pad, CHARSET, 16, batch_size=50, debug=True)
+
+if __name__ == '__main__':
+    try:
+        main()
+    except (KeyboardInterrupt, EOFError):
+        print('\n[!] Interrupt')