Function C_Digest 

pub unsafe extern "C" fn C_Digest(
    hSession: CK_SESSION_HANDLE,
    pData: CK_BYTE_PTR,
    ulDataLen: CK_ULONG,
    pDigest: CK_BYTE_PTR,
    pulDigestLen: CK_ULONG_PTR,
) -> CK_RV