Utils code for generating RSA license key system with pem using signatures

cryptography_public_encryption.py

import os
import sys
from datetime import datetime
from cryptography.hazmat.primitives import hashes
from cryptography.hazmat.primitives.asymmetric import rsa, padding
from cryptography.exceptions import InvalidSignature
from cryptography.hazmat.primitives import serialization


def get_private_key():
    with open("keys/private_key.pem", "rb") as key_file:
        private_key = serialization.load_pem_private_key(
            key_file.read(),
            password=None,
        )
    return private_key


def get_public_key():
    with open("keys/public_key.pem", "rb") as key_file:
        public_key = serialization.load_pem_public_key(
            key_file.read(),
        )
    return public_key


def generate_key_pair():
    key_size = 2048
    private_key = rsa.generate_private_key(
        public_exponent=65537,  # Do not change
        key_size=key_size,
    )
    public_key = private_key.public_key()
    pem_public_key = public_key.public_bytes(
        encoding=serialization.Encoding.PEM,
        format=serialization.PublicFormat.SubjectPublicKeyInfo,
    )

    pem_private_key = private_key.private_bytes(
        encoding=serialization.Encoding.PEM,
        format=serialization.PrivateFormat.PKCS8,
        encryption_algorithm=serialization.NoEncryption(),
    )
    print(pem_public_key.decode())
    print(pem_private_key.decode())


def sign(message, private_key):
    return private_key.sign(
        message,
        padding.PSS(
            mgf=padding.MGF1(hashes.SHA256()), salt_length=padding.PSS.MAX_LENGTH
        ),
        hashes.SHA256(),
    )


def verify(signature, message):
    public_key = get_public_key()
    try:
        signature_bytes = bytes.fromhex(signature)
        public_key.verify(
            signature_bytes,
            message.encode(),
            padding.PSS(
                mgf=padding.MGF1(hashes.SHA256()), salt_length=padding.PSS.MAX_LENGTH
            ),
            hashes.SHA256(),
        )
        return True
    except:
        return False


def generate_da_keys(n):
    keys = []
    for i in range(n):
        key_number = str(i).encode()
        timestamp = datetime.now().strftime("%Y-%m-%d %H:%M:%S.%f").encode()
        seed = str(hash(datetime.now())).encode()
        random_bytes = os.urandom(16).hex().encode()
        message = (
            b"MuseAI Key number "
            + key_number
            + b" generated at "
            + timestamp
            + b" with seed "
            + seed
            + b" random "
            + random_bytes
        )

        signature = sign(message, get_private_key())

        keys.append((message, signature.hex()))
    for k in keys:
        print(k[0].decode())
        print(k[1])