ecdsaKeyGen.py

import os
from cryptography.hazmat.backends import default_backend
from cryptography.hazmat.primitives.asymmetric import ec
from cryptography.hazmat.primitives import serialization


def generate_key_pair():
    private_key = ec.generate_private_key(ec.SECP256R1(), default_backend())
    public_key = private_key.public_key()
    return private_key, public_key

def save_key_to_pem_file(key, file_name):
    with open(file_name, 'wb') as f:
        if isinstance(key, ec.EllipticCurvePrivateKey):
            pem_key = key.private_bytes(
                encoding=serialization.Encoding.PEM,
                format=serialization.PrivateFormat.PKCS8,
                encryption_algorithm=serialization.NoEncryption()
            )
        elif isinstance(key, ec.EllipticCurvePublicKey):
            pem_key = key.public_bytes(
                encoding=serialization.Encoding.PEM,
                format=serialization.PublicFormat.SubjectPublicKeyInfo
            )
        else:
            raise ValueError("Invalid key type")
        f.write(pem_key)


def main():
    private_key_file = 'private_key.pem'
    public_key_file = 'public_key.pem'

    # check if the key files already exist
    if not os.path.exists(private_key_file):
        private_key, public_key = generate_key_pair()

        # Save the keys to PEM format files
        save_key_to_pem_file(private_key, private_key_file)
        save_key_to_pem_file(public_key, public_key_file)

        print("Private key saved to private_key.pem")
        print("Public key saved to public_key.pem")
    else:
        print("Private key file already exists, skipping key generation.")


if __name__ == "__main__":
    main()