'Initialize this PKCS#1 PSS signature scheme object.
:Parameters:
key : an RSA key object
If a private half is given, both signature and verification are possible.
If a public half is given, only verification is possible.
mgfunc : callable
A mask generation function that accepts two parameters: a string to
use as seed, and the lenth of the mask to generate, in bytes.
saltLen : int
Length of the salt, in bytes.'

def __init__(self, key, mgfunc, saltLen):

    self._key = key
    self._saltLen = saltLen
    self._mgfunc = mgfunc
