Add SpringSessionBackedReactiveSessionRegistry

Closes gh-2824

spring-session-core/src/main/java/org/springframework/session/security/SpringSessionBackedReactiveSessionRegistry.java

@@ -0,0 +1,135 @@
+/*
+ * Copyright 2014-2024 the original author or authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      https://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.springframework.session.security;
+
+import reactor.core.publisher.Flux;
+import reactor.core.publisher.Mono;
+
+import org.springframework.security.authentication.AbstractAuthenticationToken;
+import org.springframework.security.core.Authentication;
+import org.springframework.security.core.authority.AuthorityUtils;
+import org.springframework.security.core.context.SecurityContext;
+import org.springframework.security.core.session.ReactiveSessionInformation;
+import org.springframework.security.core.session.ReactiveSessionRegistry;
+import org.springframework.session.ReactiveFindByIndexNameSessionRepository;
+import org.springframework.session.ReactiveSessionRepository;
+import org.springframework.session.Session;
+import org.springframework.util.Assert;
+
+/**
+ * A {@link ReactiveSessionRegistry} that retrieves session information from Spring
+ * Session, rather than maintaining it itself. This allows concurrent session management
+ * with Spring Security in a clustered environment.
+ * <p>
+ * Relies on being able to derive the same String-based representation of the principal
+ * given to {@link #getAllSessions(Object)} as used by Spring Session in order to look up
+ * the user's sessions.
+ * <p>
+ *
+ * @param <S> the {@link Session} type.
+ * @author Marcus da Coregio
+ * @since 3.3
+ */
+public final class SpringSessionBackedReactiveSessionRegistry<S extends Session> implements ReactiveSessionRegistry {
+
+	private static final String SPRING_SECURITY_CONTEXT = "SPRING_SECURITY_CONTEXT";
+
+	private final ReactiveSessionRepository<S> sessionRepository;
+
+	private final ReactiveFindByIndexNameSessionRepository<S> indexedSessionRepository;
+
+	public SpringSessionBackedReactiveSessionRegistry(ReactiveSessionRepository<S> sessionRepository,
+			ReactiveFindByIndexNameSessionRepository<S> indexedSessionRepository) {
+		Assert.notNull(sessionRepository, "sessionRepository cannot be null");
+		Assert.notNull(indexedSessionRepository, "indexedSessionRepository cannot be null");
+		this.sessionRepository = sessionRepository;
+		this.indexedSessionRepository = indexedSessionRepository;
+	}
+
+	@Override
+	public Flux<ReactiveSessionInformation> getAllSessions(Object principal) {
+		Authentication authenticationToken = getAuthenticationToken(principal);
+		return this.indexedSessionRepository.findByPrincipalName(authenticationToken.getName())
+			.flatMapMany((sessionMap) -> Flux.fromIterable(sessionMap.entrySet()))
+			.map((entry) -> new SpringSessionBackedReactiveSessionInformation(entry.getValue()));
+	}
+
+	@Override
+	public Mono<Void> saveSessionInformation(ReactiveSessionInformation information) {
+		return Mono.empty();
+	}
+
+	@Override
+	public Mono<ReactiveSessionInformation> getSessionInformation(String sessionId) {
+		return this.sessionRepository.findById(sessionId).map(SpringSessionBackedReactiveSessionInformation::new);
+	}
+
+	@Override
+	public Mono<ReactiveSessionInformation> removeSessionInformation(String sessionId) {
+		return Mono.empty();
+	}
+
+	@Override
+	public Mono<ReactiveSessionInformation> updateLastAccessTime(String sessionId) {
+		return Mono.empty();
+	}
+
+	private static Authentication getAuthenticationToken(Object principal) {
+		return new AbstractAuthenticationToken(AuthorityUtils.NO_AUTHORITIES) {
+
+			@Override
+			public Object getCredentials() {
+				return null;
+			}
+
+			@Override
+			public Object getPrincipal() {
+				return principal;
+			}
+
+		};
+	}
+
+	class SpringSessionBackedReactiveSessionInformation extends ReactiveSessionInformation {
+
+		SpringSessionBackedReactiveSessionInformation(S session) {
+			super(resolvePrincipalName(session), session.getId(), session.getLastAccessedTime());
+		}
+
+		private static String resolvePrincipalName(Session session) {
+			String principalName = session
+				.getAttribute(ReactiveFindByIndexNameSessionRepository.PRINCIPAL_NAME_INDEX_NAME);
+			if (principalName != null) {
+				return principalName;
+			}
+			SecurityContext securityContext = session.getAttribute(SPRING_SECURITY_CONTEXT);
+			if (securityContext != null && securityContext.getAuthentication() != null) {
+				return securityContext.getAuthentication().getName();
+			}
+			return "";
+		}
+
+		@Override
+		public Mono<Void> invalidate() {
+			return super.invalidate()
+				.then(Mono.defer(() -> SpringSessionBackedReactiveSessionRegistry.this.sessionRepository
+					.deleteById(getSessionId())));
+		}
+
+	}
+
+}