dsp-blockchain/create_keys.py

import os
import rsa

from cryptography.hazmat.backends import default_backend
#from cryptography.hazmat.primitives.asymmetric import rsa
from cryptography.hazmat.primitives import serialization
from cryptography.fernet import Fernet

def make_keys(contract_name):

    # create pubkey and private key for new contract
    (public_key,private_key)=rsa.newkeys(2048)

    # save them in contract folder
    path = f'contract_keys\\{contract_name}\\'
    os.makedirs(path, exist_ok=True)
    
    # write pubkey
    with open(path + 'publickey.key','wb') as f:
        f.write(public_key.save_pkcs1('PEM'))

    # write private key
    with open(path + 'privatekey.key','wb') as f:
        f.write(private_key.save_pkcs1('PEM'))    
    
    # create semmetric key
    symmetric_key = Fernet.generate_key()
    with open(path + 'symmetric.key','wb') as f:
        f.write(symmetric_key)

# retrieve public key
def get_keys(contract_name):
    path = 'contract_keys\\' + contract_name  + '\\publickey.key'

    # retreive public key form path
    with open(path, 'rb') as f:
        return rsa.PublicKey.load_pkcs1(f.read())

# retrieve symmetric key
def get_symmetric_key(contract_name):
    path = 'contract_keys\\' + contract_name  + '\\symmetric.key'

    # read semmetric key from file
    with open(path, 'rb') as f:
        return f.read()

# get private key
def get_private_key(contract_name):
    path = 'contract_keys\\' + contract_name  + '\\privatekey.key'

    # read private key from file
    with open(path, 'rb') as f:
        return rsa.PrivateKey.load_pkcs1(f.read())

# get key in plain text (only public key)
def get_plain_key(contract_name):
    path = 'contract_keys\\' + contract_name  + '\\publickey.key'

    # read file and remove unnecessary suf 
    with open(path, 'rt') as f:
        return f.read().split('-----')[2].strip().replace('\n', '')