dsp-blockchain/gui/encyption.py

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

from create_keys import get_keys, get_symmetric_key, get_private_key


def encrypt_data(contract, block_string): 
    symmetric_key = get_symmetric_key(contract)
    pubkey = get_keys(contract)

    chiper = Fernet(symmetric_key)

    data = str(chiper.encrypt(block_string))

    encrypted_key = str(rsa.encrypt(symmetric_key,pubkey))
    return data, encrypted_key


def decrypt_data(name, t):
    print('DATA OF TRANSACTION: ', type(t.data), t.data)
    private_key = get_private_key(name)
    en_key = t.encrypted_key
    print('ENCRYPTED KEY: ', type(en_key), en_key)
    key = rsa.decrypt(en_key, private_key)
    cipher = Fernet(key)
    decrypted_data = cipher.decrypt(t.data)
    print(decrypted_data.decode(), t.data)