Can't switch TripleDES to CFB or OFB mode

Question

I'm encrypting some data using TripleDES and three different modes (CBC, CFB and OFB) like this:

using (TripleDES alg = TripleDES.Create())
{
    var param = GetParams();
    alg.KeySize = param.keySize;
    alg.BlockSize = param.blockSize;
    alg.Key = param.sessionKey;
    alg.IV = param.IV;
    alg.Mode = param.mode;

    using (ICryptoTransform encryptor = alg.CreateEncryptor(alg.Key, alg.IV))

The last line throws an exception (Specified cipher mode is not valid for this algorithm.) whenever I use CFB or OFB as the mode.

Is there anything I'm doing wrong?

Answer 1

Basically because it is not supported by .Net Core. See https://github.com/dotnet/runtime/pull/38211

Except if you are working on a legacy code, you should use AES instead of 3DES.