ALL the CTFS of Crypto2025 finally

crypto-asimmetric/RSA-6/chall.py

@@ -0,0 +1,19 @@
+from Cryptodome.Util.number import bytes_to_long, getPrime, inverse
+from secret import flag
+
+p, q = getPrime(512), getPrime(512)
+n = p*q
+e = 65537
+m = bytes_to_long(flag.encode())
+print(pow(m, e, n))
+
+for _ in range(3):
+    req = input()
+    if req[0] == 'e':
+        print(pow(int(req[1:]), e, n))
+    elif req[0] == 'd':
+        phi = (p-1)*(q-1)
+        d = inverse(e, phi)
+        dec = pow(int(req[1:]), d, n)
+        assert dec != m
+        print(dec)