dsp-blockchain/create_keys.py

import rsa
import os
#from cryptography.fernet import Fernet
# create the symmetric key only for the JSON file - we are going to only encrypt the keys 
#key = Fernet.generate_key()

# write the symmetric key to a file
#k = open('symmetric.key','wb')
#k.write(key)
#k.close()

# create the pub & private keys for the parties

from cryptography.hazmat.backends import default_backend
from cryptography.hazmat.primitives.asymmetric import rsa
from cryptography.hazmat.primitives import serialization

def make_keys(company):
    #(pubkey,privkey)=rsa.newkeys(2048)
    private_key = rsa.generate_private_key(
        public_exponent=65537,
        key_size=2048,
        backend=default_backend()
        )
    public_key = private_key.public_key()

    pem = public_key.public_bytes(
        encoding=serialization.Encoding.PEM,
        format=serialization.PublicFormat.SubjectPublicKeyInfo
    )

    with open('companies\\' + company + '_publickey.key','wb') as f:
        f.write(pem)

    pem = private_key.private_bytes(
        encoding=serialization.Encoding.PEM,
        format=serialization.PrivateFormat.PKCS8,
        encryption_algorithm=serialization.NoEncryption()
    )

    with open('companies\\' + company + '_privatekey.key','wb') as f:
        f.write(pem)    
    
def get_keys(company):
    path = 'companies\\' + company + '_publickey.key'
    if not os.path.exists(path):
        make_keys(company)

    with open(path, 'rb') as f:
        public_key = serialization.load_pem_public_key(
            f.read(),
            backend=default_backend()
            )
        return public_key