Python: Asymmetric Encryption and Decryption

# package used in this gist: pyca/cryptography
# Step 1: Generating a key
from cryptography.hazmat.backends import default_backend
from cryptography.hazmat.primitives.asymmetric import rsa
private_key = rsa.generate_private_key(
        public_exponent=65537,
        key_size=2048,
        backend=default_backend()
    )
public_key = private_key.public_key()


# Step 2: Storing the keys
from cryptography.hazmat.primitives import serialization
pem = private_key.private_bytes(
        encoding=serialization.Encoding.PEM,
        format=serialization.PrivateFormat.PKCS8,
        encryption_algorithm=serialization.NoEncryption()
    )
with open('private_key.pem', 'wb') as f:
    f.write(pem)

pem = public_key.public_bytes(
        encoding=serialization.Encoding.PEM,
        format=serialization.PublicFormat.SubjectPublicKeyInfo
    )
with open('public_key.pem', 'wb') as f:
    f.write(pem)


# Step 3: Reading the keys back in (for demonstration purposes)
from cryptography.hazmat.backends import default_backend
from cryptography.hazmat.primitives import serialization
with open("private_key.pem", "rb") as key_file:
        private_key = serialization.load_pem_private_key(
            key_file.read(),
            password=None,
            backend=default_backend()
        )
with open("public_key.pem", "rb") as key_file:
        public_key = serialization.load_pem_public_key(
            key_file.read(),
            backend=default_backend()
        )


# Step 4: Encrypting and decrypting
from cryptography.hazmat.primitives import hashes
from cryptography.hazmat.primitives.asymmetric import padding

message = b'encrypt me!'
encrypted = public_key.encrypt(
        message,
        padding.OAEP(
            mgf=padding.MGF1(algorithm=hashes.SHA256()),
            algorithm=hashes.SHA256(),
            label=None
        )
    )
original_message = private_key.decrypt(
        encrypted,
        padding.OAEP(
            mgf=padding.MGF1(algorithm=hashes.SHA256()),
            algorithm=hashes.SHA256(),
            label=None
        )
    )

# Checking the results
print(original_message)
# Result: b'encrypt me!'
print(message == original_message)
# Result: True