from Cryptodome.PublicKey import RSA from Cryptodome.Cipher import AES, PKCS1_OAEP file_in = open("encrypted_data.bin", "rb") private_key = RSA.import_key(open("private.pem").read()) enc_session_key, nonce, tag, ciphertext = \ [ file_in.read(x) for x in (private_key.size_in_bytes(), 16, 16, -1) ] # Decrypt the session key with the private RSA key cipher_rsa = PKCS1_OAEP.new(private_key) session_key = cipher_rsa.decrypt(enc_session_key) # Decrypt the data with the AES session key cipher_aes = AES.new(session_key, AES.MODE_EAX, nonce) data = cipher_aes.decrypt_and_verify(ciphertext, tag) print(data.decode("utf-8"))