Add Explicit SessionAuthenticationStrategy Option

SessionAuthenticationFilter requires accessing the HttpSession to do its
job. Previously, there was no way to just disable the
SessionAuthenticationFilter despite the fact that
SessionAuthenticationStrategy is invoked by the authentication filters
directly.

This commit adds an option to disable SessionManagmentFilter in favor of
requiring explicit SessionAuthenticationStrategy invocation already
performed by the authentication filters.

Closes gh-11455

Author: rwinch

Diff for: config/src/main/java/org/springframework/security/config/annotation/web/configurers/SessionManagementConfigurer.java

@@ -135,6 +135,8 @@ public final class SessionManagementConfigurer<H extends HttpSecurityBuilder<H>>
 
 	private AuthenticationFailureHandler sessionAuthenticationFailureHandler;
 
+	private boolean requireExplicitAuthenticationStrategy;
+
 	/**
 	 * Creates a new instance
 	 * @see HttpSecurity#sessionManagement()
@@ -155,6 +157,19 @@ public SessionManagementConfigurer<H> invalidSessionUrl(String invalidSessionUrl
 		return this;
 	}
 
+	/**
+	 * Setting this means that explicit invocation of
+	 * {@link SessionAuthenticationStrategy} is required.
+	 * @param requireExplicitAuthenticationStrategy require explicit invocation of
+	 * {@link SessionAuthenticationStrategy}
+	 * @return the {@link SessionManagementConfigurer} for further customization
+	 */
+	public SessionManagementConfigurer<H> requireExplicitAuthenticationStrategy(
+			boolean requireExplicitAuthenticationStrategy) {
+		this.requireExplicitAuthenticationStrategy = requireExplicitAuthenticationStrategy;
+		return this;
+	}
+
 	/**
 	 * Setting this attribute will inject the provided invalidSessionStrategy into the
 	 * {@link SessionManagementFilter}. When an invalid session ID is submitted, the
@@ -351,6 +366,28 @@ public void init(H http) {
 
 	@Override
 	public void configure(H http) {
+		SessionManagementFilter sessionManagementFilter = createSessionManagementFilter(http);
+		if (sessionManagementFilter != null) {
+			http.addFilter(sessionManagementFilter);
+		}
+		if (isConcurrentSessionControlEnabled()) {
+			ConcurrentSessionFilter concurrentSessionFilter = createConcurrencyFilter(http);
+
+			concurrentSessionFilter = postProcess(concurrentSessionFilter);
+			http.addFilter(concurrentSessionFilter);
+		}
+		if (!this.enableSessionUrlRewriting) {
+			http.addFilter(new DisableEncodeUrlFilter());
+		}
+		if (this.sessionPolicy == SessionCreationPolicy.ALWAYS) {
+			http.addFilter(new ForceEagerSessionCreationFilter());
+		}
+	}
+
+	private SessionManagementFilter createSessionManagementFilter(H http) {
+		if (this.requireExplicitAuthenticationStrategy) {
+			return null;
+		}
 		SecurityContextRepository securityContextRepository = http.getSharedObject(SecurityContextRepository.class);
 		SessionManagementFilter sessionManagementFilter = new SessionManagementFilter(securityContextRepository,
 				getSessionAuthenticationStrategy(http));
@@ -371,20 +408,7 @@ public void configure(H http) {
 			sessionManagementFilter.setTrustResolver(trustResolver);
 		}
 		sessionManagementFilter.setSecurityContextHolderStrategy(getSecurityContextHolderStrategy());
-		sessionManagementFilter = postProcess(sessionManagementFilter);
-		http.addFilter(sessionManagementFilter);
-		if (isConcurrentSessionControlEnabled()) {
-			ConcurrentSessionFilter concurrentSessionFilter = createConcurrencyFilter(http);
-
-			concurrentSessionFilter = postProcess(concurrentSessionFilter);
-			http.addFilter(concurrentSessionFilter);
-		}
-		if (!this.enableSessionUrlRewriting) {
-			http.addFilter(new DisableEncodeUrlFilter());
-		}
-		if (this.sessionPolicy == SessionCreationPolicy.ALWAYS) {
-			http.addFilter(new ForceEagerSessionCreationFilter());
-		}
+		return postProcess(sessionManagementFilter);
 	}
 
 	private ConcurrentSessionFilter createConcurrencyFilter(H http) {

Diff for: config/src/main/java/org/springframework/security/config/http/HttpConfigurationBuilder.java

@@ -103,6 +103,8 @@ class HttpConfigurationBuilder {
 
 	private static final String OPT_CHANGE_SESSION_ID = "changeSessionId";
 
+	private static final String ATT_AUTHENTICATION_STRATEGY_EXPLICIT_INVOCATION = "authentication-strategy-explicit-invocation";
+
 	private static final String ATT_INVALID_SESSION_URL = "invalid-session-url";
 
 	private static final String ATT_SESSION_AUTH_STRATEGY_REF = "session-authentication-strategy-ref";
@@ -538,7 +540,11 @@ else if (StringUtils.hasText(invalidSessionStrategyRef)) {
 			sessionMgmtFilter.addPropertyReference("invalidSessionStrategy", invalidSessionStrategyRef);
 		}
 		sessionMgmtFilter.addConstructorArgReference(sessionAuthStratRef);
-		this.sfpf = (RootBeanDefinition) sessionMgmtFilter.getBeanDefinition();
+		boolean registerSessionMgmtFilter = (sessionMgmtElt == null
+				|| !"true".equals(sessionMgmtElt.getAttribute(ATT_AUTHENTICATION_STRATEGY_EXPLICIT_INVOCATION)));
+		if (registerSessionMgmtFilter) {
+			this.sfpf = (RootBeanDefinition) sessionMgmtFilter.getBeanDefinition();
+		}
 		this.sessionStrategyRef = new RuntimeBeanReference(sessionAuthStratRef);
 	}
 

Diff for: config/src/main/resources/org/springframework/security/config/spring-security-5.8.rnc

@@ -917,6 +917,9 @@ session-management =
 	## Session-management related functionality is implemented by the addition of a SessionManagementFilter to the filter stack.
 	element session-management {session-management.attlist, concurrency-control?}
 
+session-management.attlist &=
+	## Specifies that SessionAuthenticationStrategy must be explicitly invoked. Default false (i.e. SessionManagementFilter will implicitly invoke SessionAuthenticationStrategy).
+	attribute authentication-strategy-explicit-invocation {xsd:boolean}?
 session-management.attlist &=
 	## Indicates how session fixation protection will be applied when a user authenticates. If set to "none", no protection will be applied. "newSession" will create a new empty session, with only Spring Security-related attributes migrated. "migrateSession" will create a new session and copy all session attributes to the new session. In Servlet 3.1 (Java EE 7) and newer containers, specifying "changeSessionId" will keep the existing session and use the container-supplied session fixation protection (HttpServletRequest#changeSessionId()). Defaults to "changeSessionId" in Servlet 3.1 and newer containers, "migrateSession" in older containers. Throws an exception if "changeSessionId" is used in older containers.
 	attribute session-fixation-protection {"none" | "newSession" | "migrateSession" | "changeSessionId" }?

Diff for: config/src/main/resources/org/springframework/security/config/spring-security-5.8.xsd

@@ -2662,6 +2662,13 @@
   </xs:attributeGroup>
 
   <xs:attributeGroup name="session-management.attlist">
+      <xs:attribute name="authentication-strategy-explicit-invocation" type="xs:boolean">
+         <xs:annotation>
+            <xs:documentation>Specifies that SessionAuthenticationStrategy must be explicitly invoked. Default false
+                (i.e. SessionManagementFilter will implicitly invoke SessionAuthenticationStrategy).
+                </xs:documentation>
+         </xs:annotation>
+      </xs:attribute>
       <xs:attribute name="session-fixation-protection">
          <xs:annotation>
             <xs:documentation>Indicates how session fixation protection will be applied when a user authenticates. If

Diff for: docs/modules/ROOT/pages/servlet/appendix/namespace/http.adoc

@@ -2243,6 +2243,10 @@ Session-management related functionality is implemented by the addition of a `Se
 === <session-management> Attributes
 
 
+[[nsa-session-management-authentication-strategy-explicit-invocation]]
+* **authentication-strategy-explicit-invocation**
+Setting this attribute to true will mean that `SessionManagementFilter` will not be injected and explicit invocation of SessionAuthenticationStrategy is required.
+
 [[nsa-session-management-invalid-session-url]]
 * **invalid-session-url**
 Setting this attribute will inject the `SessionManagementFilter` with a `SimpleRedirectInvalidSessionStrategy` configured with the attribute value.