import base64
import subprocess

# Открываем закрытый ключ DH
with open("dhkeyA.pem", "rb") as key_file:
    key_data = key_file.read()

# Открываем открытый ключ DH
with open("dhpubB.pem", "rb") as peerkey_file:
    peerkey_data = peerkey_file.read()

pkeyutl_command = ["openssl", "pkeyutl", "-derive", "-inkey", "dhkeyA.pem", "-peerkey", "dhpubB.pem", "-out", "secretShared.bin"]
subprocess.run(pkeyutl_command, input=key_data, check=True)

def shared_key_reader():
    # Считываем общий секрет
    with open("secretShared.bin", "rb") as shared_file:
        shared_secret = shared_file.read().hex()

        return shared_secret

print(shared_key_reader())