softHSM2 AES Key Type Issue

[blueaxions]

Hello,

I'm testing a softHSM2 setup with the following code on rhel 9.4 system running in FIPS mode:

import pkcs11
from cryptography.hazmat.primitives import serialization
from cryptography.hazmat.primitives.ciphers import Cipher, algorithms, modes

# Initialize PKCS#11 library and connect to SoftHSM
lib = pkcs11.lib("/usr/local/lib/softhsm/libsofthsm2.so") # Adjust path if necessary
token = lib.get_token(token_label='MyToken') # Replace with your token label

with token.open(rw=True, user_pin="your_pin") as session:
    # Generate a symmetric key
    key = session.generate_key(pkcs11.KeyType.AES, 256, label="MySymmetricKey", template={Attribute.SENSITIVE: False, Attribute.EXTRACTABLE: True,}, store=True)

    # Encrypt some data
    data = b"Hello, world!"
    iv = os.urandom(16)
    cipher = Cipher(algorithms.AES(key), modes.CBC(iv))
    encryptor = cipher.encryptor()
    ciphertext = encryptor.update(data) + encryptor.finalize()

    # Decrypt the data
    decryptor = cipher.decryptor()
    plaintext = decryptor.update(ciphertext) + decryptor.finalize()

    print("Plaintext:", plaintext)

When I run the above code, I get the following key type error:

TypeError: memoryview: a bytes-like object is required, not 'SecretKey'

While I understand that the AES Cipher() method doesn't like the key format, I don't know how to convert the key from session.generate_key() method to a format that's acceptable.

Thanks in advance!

Best,
PE