SEC-3109: DelegatingSecurityContextExecutor fails with same Thread

Previously DelegatingSecurityContextRunnable and DelegatingSecurityContextCallable
would not setup the SecurityContext if it was on the same thread as it was created.
This was intended to fix SEC-3031 but simply caused more problems.

This commit changes the strategy to keep track of the previous SecurityContext
and restore it (or clear it out if it was originally empty).

core/src/main/java/org/springframework/security/concurrent/DelegatingSecurityContextCallable.java

@@ -25,10 +25,8 @@ import org.springframework.util.Assert;
  * then removing the {@link SecurityContext} after the delegate has completed.
  * </p>
  * <p>
- * By default the {@link SecurityContext} is only setup if {@link #call()} is
- * invoked on a separate {@link Thread} than the
- * {@link DelegatingSecurityContextCallable} was created on. This can be
- * overridden by setting {@link #setEnableOnOriginalThread(boolean)} to true.
+ * If there is a {@link SecurityContext} that already exists, it will be
+ * restored after the {@link #call()} method is invoked.
  * </p>
  *
  * @author Rob Winch
@@ -38,63 +36,60 @@ public final class DelegatingSecurityContextCallable<V> implements Callable<V> {
 
     private final Callable<V> delegate;
 
-    private final SecurityContext securityContext;
 
-    private final Thread originalThread;
+    /**
+     * The {@link SecurityContext} that the delegate {@link Callable} will be
+     * ran as.
+     */
+    private final SecurityContext delegateSecurityContext;
 
-    private boolean enableOnOriginalThread;
+    /**
+     * The {@link SecurityContext} that was on the {@link SecurityContextHolder}
+     * prior to being set to the delegateSecurityContext.
+     */
+    private SecurityContext originalSecurityContext;
 
     /**
-     * Creates a new {@link DelegatingSecurityContextCallable} with a specific {@link SecurityContext}.
-     * @param delegate the delegate {@link DelegatingSecurityContextCallable} to run with the specified
-     * {@link SecurityContext}. Cannot be null.
-     * @param securityContext the {@link SecurityContext} to establish for the delegate {@link Callable}. Cannot be
-     * null.
+     * Creates a new {@link DelegatingSecurityContextCallable} with a specific
+     * {@link SecurityContext}.
+     * @param delegate the delegate {@link DelegatingSecurityContextCallable} to run with
+     * the specified {@link SecurityContext}. Cannot be null.
+     * @param securityContext the {@link SecurityContext} to establish for the delegate
+     * {@link Callable}. Cannot be null.
      */
-    public DelegatingSecurityContextCallable(Callable<V> delegate, SecurityContext securityContext) {
+    public DelegatingSecurityContextCallable(Callable<V> delegate,
+            SecurityContext securityContext) {
         Assert.notNull(delegate, "delegate cannot be null");
         Assert.notNull(securityContext, "securityContext cannot be null");
         this.delegate = delegate;
-        this.securityContext = securityContext;
-        this.originalThread = Thread.currentThread();
+        this.delegateSecurityContext = securityContext;
     }
 
     /**
-     * Creates a new {@link DelegatingSecurityContextCallable} with the {@link SecurityContext} from the
-     * {@link SecurityContextHolder}.
-     * @param delegate the delegate {@link Callable} to run under the current {@link SecurityContext}. Cannot be null.
+     * Creates a new {@link DelegatingSecurityContextCallable} with the
+     * {@link SecurityContext} from the {@link SecurityContextHolder}.
+     * @param delegate the delegate {@link Callable} to run under the current
+     * {@link SecurityContext}. Cannot be null.
      */
     public DelegatingSecurityContextCallable(Callable<V> delegate) {
         this(delegate, SecurityContextHolder.getContext());
     }
 
-    /**
-     * Determines if the SecurityContext should be transfered if {@link #call()}
-     * is invoked on the same {@link Thread} the
-     * {@link DelegatingSecurityContextCallable} was created on.
-     *
-     * @param enableOnOriginalThread
-     *            if false (default), will only transfer the
-     *            {@link SecurityContext} if {@link #call()} is invoked on a
-     *            different {@link Thread} than the
-     *            {@link DelegatingSecurityContextCallable} was created on.
-     *
-     * @since 4.0.2
-     */
-    public void setEnableOnOriginalThread(boolean enableOnOriginalThread) {
-        this.enableOnOriginalThread = enableOnOriginalThread;
-    }
-
     public V call() throws Exception {
-        if(!enableOnOriginalThread && originalThread == Thread.currentThread()) {
-            return delegate.call();
-        }
+        this.originalSecurityContext = SecurityContextHolder.getContext();
+
         try {
-            SecurityContextHolder.setContext(securityContext);
+            SecurityContextHolder.setContext(delegateSecurityContext);
             return delegate.call();
         }
         finally {
-            SecurityContextHolder.clearContext();
+            SecurityContext emptyContext = SecurityContextHolder.createEmptyContext();
+            if(emptyContext.equals(originalSecurityContext)) {
+                SecurityContextHolder.clearContext();
+            } else {
+                SecurityContextHolder.setContext(originalSecurityContext);
+            }
+            this.originalSecurityContext = null;
         }
     }
 

core/src/main/java/org/springframework/security/concurrent/DelegatingSecurityContextRunnable.java

@@ -22,11 +22,10 @@ import org.springframework.util.Assert;
  * before invoking the delegate {@link Runnable} and then removing the
  * {@link SecurityContext} after the delegate has completed.
  * </p>
+ *
  * <p>
- * By default the {@link SecurityContext} is only setup if {@link #run()} is
- * invoked on a separate {@link Thread} than the
- * {@link DelegatingSecurityContextRunnable} was created on. This can be
- * overridden by setting {@link #setEnableOnOriginalThread(boolean)} to true.
+ * If there is a {@link SecurityContext} that already exists, it will be
+ * restored after the {@link #run()} method is invoked.
  * </p>
  *
  * @author Rob Winch
@@ -36,62 +35,59 @@ public final class DelegatingSecurityContextRunnable implements Runnable {
 
     private final Runnable delegate;
 
-    private final SecurityContext securityContext;
-
-    private final Thread originalThread;
+    /**
+     * The {@link SecurityContext} that the delegate {@link Runnable} will be
+     * ran as.
+     */
+    private final SecurityContext delegateSecurityContext;
 
-    private boolean enableOnOriginalThread;
+    /**
+     * The {@link SecurityContext} that was on the {@link SecurityContextHolder}
+     * prior to being set to the delegateSecurityContext.
+     */
+    private SecurityContext originalSecurityContext;
 
     /**
-     * Creates a new {@link DelegatingSecurityContextRunnable} with a specific {@link SecurityContext}.
-     * @param delegate the delegate {@link Runnable} to run with the specified {@link SecurityContext}. Cannot be null.
-     * @param securityContext the {@link SecurityContext} to establish for the delegate {@link Runnable}. Cannot be
-     * null.
+     * Creates a new {@link DelegatingSecurityContextRunnable} with a specific
+     * {@link SecurityContext}.
+     * @param delegate the delegate {@link Runnable} to run with the specified
+     * {@link SecurityContext}. Cannot be null.
+     * @param securityContext the {@link SecurityContext} to establish for the delegate
+     * {@link Runnable}. Cannot be null.
      */
-    public DelegatingSecurityContextRunnable(Runnable delegate, SecurityContext securityContext) {
+    public DelegatingSecurityContextRunnable(Runnable delegate,
+            SecurityContext securityContext) {
         Assert.notNull(delegate, "delegate cannot be null");
         Assert.notNull(securityContext, "securityContext cannot be null");
         this.delegate = delegate;
-        this.securityContext = securityContext;
-        this.originalThread = Thread.currentThread();
+        this.delegateSecurityContext = securityContext;
     }
 
     /**
-     * Creates a new {@link DelegatingSecurityContextRunnable} with the {@link SecurityContext} from the
-     * {@link SecurityContextHolder}.
-     * @param delegate the delegate {@link Runnable} to run under the current {@link SecurityContext}. Cannot be null.
+     * Creates a new {@link DelegatingSecurityContextRunnable} with the
+     * {@link SecurityContext} from the {@link SecurityContextHolder}.
+     * @param delegate the delegate {@link Runnable} to run under the current
+     * {@link SecurityContext}. Cannot be null.
      */
     public DelegatingSecurityContextRunnable(Runnable delegate) {
         this(delegate, SecurityContextHolder.getContext());
     }
 
-    /**
-     * Determines if the SecurityContext should be transfered if {@link #call()}
-     * is invoked on the same {@link Thread} the
-     * {@link DelegatingSecurityContextCallable} was created on.
-     *
-     * @param enableOnOriginalThread
-     *            if false (default), will only transfer the
-     *            {@link SecurityContext} if {@link #call()} is invoked on a
-     *            different {@link Thread} than the
-     *            {@link DelegatingSecurityContextCallable} was created on.
-     * @since 4.0.2
-     */
-    public void setEnableOnOriginalThread(boolean enableOnOriginalThread) {
-        this.enableOnOriginalThread = enableOnOriginalThread;
-    }
-
     public void run() {
-        if(!enableOnOriginalThread && originalThread == Thread.currentThread()) {
-            delegate.run();
-            return;
-        }
+        this.originalSecurityContext = SecurityContextHolder.getContext();
+
         try {
-            SecurityContextHolder.setContext(securityContext);
+            SecurityContextHolder.setContext(delegateSecurityContext);
             delegate.run();
         }
         finally {
-            SecurityContextHolder.clearContext();
+            SecurityContext emptyContext = SecurityContextHolder.createEmptyContext();
+            if(emptyContext.equals(originalSecurityContext)) {
+                SecurityContextHolder.clearContext();
+            } else {
+                SecurityContextHolder.setContext(originalSecurityContext);
+            }
+            this.originalSecurityContext = null;
         }
     }
 

core/src/test/java/org/springframework/security/concurrent/DelegatingSecurityContextCallableTests.java

@@ -50,9 +50,12 @@ public class DelegatingSecurityContextCallableTests {
 
     private ExecutorService executor;
 
+    private SecurityContext originalSecurityContext;
+
     @Before
     @SuppressWarnings("serial")
     public void setUp() throws Exception {
+        originalSecurityContext = SecurityContextHolder.createEmptyContext();
         when(delegate.call()).thenAnswer(new Returns(callableResult) {
             @Override
             public Object answer(InvocationOnMock invocation) throws Throwable {
@@ -111,17 +114,10 @@ public class DelegatingSecurityContextCallableTests {
     // SEC-3031
     @Test
     public void callOnSameThread() throws Exception {
+        originalSecurityContext = securityContext;
+        SecurityContextHolder.setContext(originalSecurityContext);
         callable = new DelegatingSecurityContextCallable<Object>(delegate,
                 securityContext);
-        securityContext = SecurityContextHolder.createEmptyContext();
-        assertWrapped(callable.call());
-    }
-
-    @Test
-    public void callOnSameThreadExplicitlyEnabled() throws Exception {
-        DelegatingSecurityContextCallable<Object> callable = new DelegatingSecurityContextCallable<Object>(delegate,
-                securityContext);
-        callable.setEnableOnOriginalThread(true);
         assertWrapped(callable.call());
     }
 
@@ -170,6 +166,6 @@ public class DelegatingSecurityContextCallableTests {
     private void assertWrapped(Object callableResult) throws Exception {
         verify(delegate).call();
         assertThat(SecurityContextHolder.getContext()).isEqualTo(
-                SecurityContextHolder.createEmptyContext());
+                originalSecurityContext);
     }
 }

core/src/test/java/org/springframework/security/concurrent/DelegatingSecurityContextRunnableTests.java

@@ -51,8 +51,11 @@ public class DelegatingSecurityContextRunnableTests {
 
     private ExecutorService executor;
 
+    private SecurityContext originalSecurityContext;
+
     @Before
     public void setUp() throws Exception {
+        originalSecurityContext = SecurityContextHolder.createEmptyContext();
         doAnswer(new Answer<Object>() {
             public Object answer(InvocationOnMock invocation) throws Throwable {
                 assertThat(SecurityContextHolder.getContext()).isEqualTo(securityContext);
@@ -110,19 +113,11 @@ public class DelegatingSecurityContextRunnableTests {
     // SEC-3031
     @Test
     public void callOnSameThread() throws Exception {
+        originalSecurityContext = securityContext;
+        SecurityContextHolder.setContext(originalSecurityContext);
         executor = synchronousExecutor();
         runnable = new DelegatingSecurityContextRunnable(delegate,
                 securityContext);
-        securityContext = SecurityContextHolder.createEmptyContext();
-        assertWrapped(runnable);
-    }
-
-    @Test
-    public void callOnSameThreadExplicitlyEnabled() throws Exception {
-        executor = synchronousExecutor();
-        DelegatingSecurityContextRunnable runnable = new DelegatingSecurityContextRunnable(delegate,
-                securityContext);
-        runnable.setEnableOnOriginalThread(true);
         assertWrapped(runnable);
     }
 
@@ -167,7 +162,7 @@ public class DelegatingSecurityContextRunnableTests {
         submit.get();
         verify(delegate).run();
         assertThat(SecurityContextHolder.getContext()).isEqualTo(
-                SecurityContextHolder.createEmptyContext());
+                originalSecurityContext);
     }
 
     private static ExecutorService synchronousExecutor() {