为什么我不能崩溃的程序，即使我正在遵循的代码，从书的“黑客-剥削的艺术”

I am following codes from book "Hacking-The art of exploitation". The source code defined in the book are come along with the CD that the author has provided. I simply compile the pre-written code.According to the book if I provide right password it should grant me access, and if I give a large string with wrong password it should also grant me access but it is denying me.The source does are as following:I am following codes from book "Hacking-The art