There are a couple of places you can look at overriding default
implementations in order to support your custom authentication
scheme. In OSEC, you can provide a custom UserService implementation
by marking it primary and adding it to the /WEB-INF/applicationContext-
security.xml (
http://stackoverflow.com/questions/1998447/cant-i-use-
annotation-to-indicate-a-bean-is-a-primary-bean).
You can also provide custom implementations of Spring Security beans
by modifying the same xml file noted above. (http://
static.springsource.org/spring-security/site/docs/3.1.x/reference/
springsecurity-single.html).
For both approaches, you can need to make sure the classes are in the
classpath at runtime. This can be done by adding a jar to /WEB-INF/
lib or the class files to the correct package directory in /WEB-INF/
classes.
-Matt