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
from cryptography.fernet import Fernet

def make_keys(contract_name):
    #(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
    )

    path = 'contract_keys\\' + contract_name + '\\'

    os.mkdir(path)
    
    with open(path + '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(path + 'privatekey.key','wb') as f:
        f.write(pem)
    
    
    symmetric_key = Fernet.generate_key()

    with open(path + 'symmetric.key','wb') as f:
        f.write(symmetric_key)
    
def get_keys(contract_name):
    path = 'contract_keys\\' + contract_name  + '\\publickey.key'

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

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

    with open(path, 'rb') as f:
        return f.read()

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

    with open(path, "rb") as key_file:
        private_key = serialization.load_pem_private_key(
            key_file.read(),
            password=None,
            backend=default_backend()
        )
    return private_key


def get_plain_key(contract_name):
    path = 'contract_keys\\' + contract_name  + '\\publickey.key'
    with open(path, 'rt') as f:
        return f.read().split('-----')[2].strip().replace('\n', '')