I have a private key that was generated by running:

openssl req -new -sha384 -x509 -days 63524 -subj "/C=CA/ST=State/L=City/O=Org/CN=Org-CA" -extensions v3_ca -keyout Org-CA.key -out Org-CA.pem -passout pass:pass1234

I need to use this private key and certificate to sign client CSRs. I used to use OpenSSL to do this, but I need to do this in C# instead.

I've found examples of what I want to do online, but those examples are using bouncy castle and an un-encrypted private key.

The key file looks like this:

-----BEGIN ENCRYPTED PRIVATE KEY-----
....
-----END ENCRYPTED PRIVATE KEY-----

And I'm trying to load it by doing this:

var privatekey = File.ReadAllBytes(@"Org-CA.key");
var rsaKeyParameters = PrivateKeyFactory.DecryptKey("pass1234".ToArray(), privatekey);

But thats not working. I get an error saying Wrong number of elements in sequence (Parameter 'seq')'

Is this how I'm supposed to be decrypting and loading the private key?