As part of rooting a device, I need to generate a 2048-bit RSASSA-PSS signature using SHA256 as the hash and MGF1-SHA256 as the mask function, for an update file I created. I can choose any key; but in case I need to, a 256-bit key is given to me. [namely, 49db67e9a6f198be22b03e84dedd69b834ba67d42e017d2f1ef08f0203010001]
However, I have no clue what those terms mean (e.g. mask function???). I have found a specification sheet online, that details how these encryption algorithms work. Would I have to follow all the steps in that file one by one, or has this algorithm already been programmed somewhere, in a way that I can provide the file and the key, and it can give me the 256-byte hash?
Is this an okay question to ask on the crypto site, or would I have to ask it elsewhere?