There were 100+ RC1 issues and 60+ RC2 issues fixed in Spring Security 4.1.
Here is the list of improvements:
LogoutSuccessHandler
(s) via LogoutConfigurer
InvalidSessionStrategy
via SessionManagementConfigurer
Filter
at a specific location in the chain using HttpSecurity.addFilterAt
ForwardAuthenticationFailureHandler
& ForwardAuthenticationSuccessHandler
Authentication.getPrincipal()
object (i.e. handling immutable custom User
domain objects)
SCryptPasswordEncoder
BytesEncryptor
implementation for BouncyCastle using AES/CBC/PKCS5Padding and AES/GCM/NoPadding algorithms
UserDetailsService
bean name
GrantedAuthority
using SecurityMockMvcResultMatchers.withAuthorities