Possible fix for SEC-2998: Make it possible for AuthenticationManagerBuilder to expose its UserDetailsService in Spring Boot

AuthenticationManagerConfiguration.java

@Order(Ordered.LOWEST_PRECEDENCE - 100)
	private static class SpringBootAuthenticationConfigurerAdapter
			extends GlobalAuthenticationConfigurerAdapter {

		private final SecurityProperties securityProperties;

		SpringBootAuthenticationConfigurerAdapter(SecurityProperties securityProperties) {
			this.securityProperties = securityProperties;
		}

		@Override
		public void init(AuthenticationManagerBuilder auth) throws Exception {
			DefaultInMemoryUserDetailsManagerConfigurer defaultInMemoryUserDetailsManagerConfigurer =
					new DefaultInMemoryUserDetailsManagerConfigurer(this.securityProperties);
			auth.apply(defaultInMemoryUserDetailsManagerConfigurer);
			auth.userDetailsService(defaultInMemoryUserDetailsManagerConfigurer.getUserDetailsService());
		}

	}