TLS1.2 DHE-RSA服务器密钥交换签名生成

Question

this answer 与我要寻找的非常接近。它说

Some bytes are added before the concatenation of t and x, so as to obtain the following structure:
00 01 FF FF ... FF 00 t x

我想知道如何精确生成t的方式。 预先感谢。