Why Spring Security InMemoryAuthentication do not authenticate me

I only have the following three classes in my project and a view file. No config files. I have tried to configure spring security on an spring mvc app.

When i run this as java application and access it in browser it asks for password.

i m entering use and password in the respective form fields but it does not authenticate.

I checked logs and found this line

Using default security password: 75a836df-d369-4600-aad2-a50567ebd283

When ii used this it successfully logged me in.

I cant understand this. Can anyone explain this to me? Am I missing something?

package hello;

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.security.config.annotation.authentication.builders.AuthenticationManagerBuilder;
import org.springframework.security.config.annotation.web.configuration.EnableWebSecurity;
import org.springframework.security.config.annotation.web.configuration.WebSecurityConfigurerAdapter;

@EnableWebSecurity
public class SecurityConfig extends WebSecurityConfigurerAdapter {

    @Autowired
    private void configureGlobal(AuthenticationManagerBuilder auth) throws Exception {
        auth.inMemoryAuthentication().withUser("user").password("password").roles("USER");


    }
}

package hello;

import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;

@SpringBootApplication
public class Application {

    public static void main(String[] args) {

        SpringApplication.run(Application.class, args);

    }

}

package hello;

import org.springframework.stereotype.Controller;
import org.springframework.ui.Model;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RequestParam;

@Controller
public class GreetingController {

    @RequestMapping("/greeting")
    private String greeting(@RequestParam(value="name", defaultValue="World", required=false) String name, Model model) {


        model.addAttribute("name", name);

        return "greeting";

    }
}