added few ctfs

cscg25/crypto/shadows-of-neon-city/exploit.py

@@ -0,0 +1,24 @@
+from pwn import remote
+import re
+from base64 import b64decode
+from sympy import factorint
+from Crypto.Util.number import bytes_to_long, inverse, long_to_bytes
+
+with remote("d7c40d8ec4e734fe7ac812f9-1338-shadows-of-neon-city.challenge.cscg.live", "1337", ssl=True) as conn:
+    data = conn.recvuntil(b":\n").decode("utf-8")
+    print(data)
+    matches = re.findall(r'(\w+)\s*=\s*([\w/=+]+)', data)
+    locals().update({key: value if not value.isdigit() else int(value) for key, value in matches})
+    cipher = bytes_to_long(b64decode(cipher))
+    p,q = factorint(n).keys()
+
+    n = p * q
+    phi_n = (p-1) * (q-1)
+    d = inverse(e, phi_n) 
+
+    plain_int = pow(cipher, d, n)
+
+    plaintext = long_to_bytes(plain_int) 
+
+    conn.sendline(plaintext)
+    conn.interactive()