Check for existing token before clearing

Closes gh-12236

config/src/test/java/org/springframework/security/config/annotation/web/configurers/CsrfConfigurerTests.java

@@ -302,6 +302,7 @@ public void logoutWhenCustomCsrfTokenRepositoryThenCsrfTokenIsCleared() throws E
 	public void loginWhenCustomCsrfTokenRepositoryThenCsrfTokenIsCleared() throws Exception {
 		CsrfTokenRepositoryConfig.REPO = mock(CsrfTokenRepository.class);
 		DefaultCsrfToken csrfToken = new DefaultCsrfToken("X-CSRF-TOKEN", "_csrf", "token");
+		given(CsrfTokenRepositoryConfig.REPO.loadToken(any())).willReturn(csrfToken);
 		given(CsrfTokenRepositoryConfig.REPO.loadDeferredToken(any(HttpServletRequest.class),
 				any(HttpServletResponse.class))).willReturn(new TestDeferredCsrfToken(csrfToken));
 		this.spring.register(CsrfTokenRepositoryConfig.class, BasicController.class).autowire();
@@ -312,6 +313,7 @@ public void loginWhenCustomCsrfTokenRepositoryThenCsrfTokenIsCleared() throws Ex
 				.param("password", "password");
 		// @formatter:on
 		this.mvc.perform(loginRequest).andExpect(redirectedUrl("/"));
+		verify(CsrfTokenRepositoryConfig.REPO).loadToken(any(HttpServletRequest.class));
 		verify(CsrfTokenRepositoryConfig.REPO).saveToken(isNull(), any(HttpServletRequest.class),
 				any(HttpServletResponse.class));
 	}
@@ -443,6 +445,7 @@ public void getLoginWhenCsrfTokenRequestAttributeHandlerSetThenRespondsWithNorma
 	public void loginWhenCsrfTokenRequestAttributeHandlerSetAndNormalCsrfTokenThenSuccess() throws Exception {
 		CsrfToken csrfToken = new DefaultCsrfToken("X-CSRF-TOKEN", "_csrf", "token");
 		CsrfTokenRepository csrfTokenRepository = mock(CsrfTokenRepository.class);
+		given(csrfTokenRepository.loadToken(any(HttpServletRequest.class))).willReturn(csrfToken);
 		given(csrfTokenRepository.loadDeferredToken(any(HttpServletRequest.class), any(HttpServletResponse.class)))
 				.willReturn(new TestDeferredCsrfToken(csrfToken));
 		CsrfTokenRequestHandlerConfig.REPO = csrfTokenRepository;
@@ -456,6 +459,7 @@ public void loginWhenCsrfTokenRequestAttributeHandlerSetAndNormalCsrfTokenThenSu
 				.param("password", "password");
 		// @formatter:on
 		this.mvc.perform(loginRequest).andExpect(redirectedUrl("/"));
+		verify(csrfTokenRepository).loadToken(any(HttpServletRequest.class));
 		verify(csrfTokenRepository).saveToken(isNull(), any(HttpServletRequest.class), any(HttpServletResponse.class));
 		verify(csrfTokenRepository, times(2)).loadDeferredToken(any(HttpServletRequest.class),
 				any(HttpServletResponse.class));
@@ -481,6 +485,7 @@ public void getLoginWhenXorCsrfTokenRequestAttributeHandlerSetThenRespondsWithMa
 	public void loginWhenXorCsrfTokenRequestAttributeHandlerSetAndMaskedCsrfTokenThenSuccess() throws Exception {
 		CsrfToken csrfToken = new DefaultCsrfToken("X-CSRF-TOKEN", "_csrf", "token");
 		CsrfTokenRepository csrfTokenRepository = mock(CsrfTokenRepository.class);
+		given(csrfTokenRepository.loadToken(any(HttpServletRequest.class))).willReturn(csrfToken);
 		given(csrfTokenRepository.loadDeferredToken(any(HttpServletRequest.class), any(HttpServletResponse.class)))
 				.willReturn(new TestDeferredCsrfToken(csrfToken));
 		CsrfTokenRequestHandlerConfig.REPO = csrfTokenRepository;
@@ -497,6 +502,7 @@ public void loginWhenXorCsrfTokenRequestAttributeHandlerSetAndMaskedCsrfTokenThe
 				.param("password", "password");
 		// @formatter:on
 		this.mvc.perform(loginRequest).andExpect(redirectedUrl("/"));
+		verify(csrfTokenRepository).loadToken(any(HttpServletRequest.class));
 		verify(csrfTokenRepository).saveToken(isNull(), any(HttpServletRequest.class), any(HttpServletResponse.class));
 		verify(csrfTokenRepository, times(3)).loadDeferredToken(any(HttpServletRequest.class),
 				any(HttpServletResponse.class));

web/src/main/java/org/springframework/security/web/csrf/CsrfAuthenticationStrategy.java

@@ -33,6 +33,7 @@
  * the next request.
  *
  * @author Rob Winch
+ * @author Steve Riesenberg
  * @since 3.2
  */
 public final class CsrfAuthenticationStrategy implements SessionAuthenticationStrategy {
@@ -65,10 +66,13 @@ public void setRequestHandler(CsrfTokenRequestHandler requestHandler) {
 	@Override
 	public void onAuthentication(Authentication authentication, HttpServletRequest request,
 			HttpServletResponse response) throws SessionAuthenticationException {
-		this.tokenRepository.saveToken(null, request, response);
-		DeferredCsrfToken deferredCsrfToken = this.tokenRepository.loadDeferredToken(request, response);
-		this.requestHandler.handle(request, response, deferredCsrfToken::get);
-		this.logger.debug("Replaced CSRF Token");
+		boolean containsToken = this.tokenRepository.loadToken(request) != null;
+		if (containsToken) {
+			this.tokenRepository.saveToken(null, request, response);
+			DeferredCsrfToken deferredCsrfToken = this.tokenRepository.loadDeferredToken(request, response);
+			this.requestHandler.handle(request, response, deferredCsrfToken::get);
+			this.logger.debug("Replaced CSRF Token");
+		}
 	}
 
 }

web/src/test/java/org/springframework/security/web/csrf/CsrfAuthenticationStrategyTests.java

@@ -36,6 +36,7 @@
 import static org.mockito.BDDMockito.given;
 import static org.mockito.Mockito.mock;
 import static org.mockito.Mockito.never;
+import static org.mockito.Mockito.times;
 import static org.mockito.Mockito.verify;
 import static org.mockito.Mockito.verifyNoMoreInteractions;
 
@@ -82,23 +83,28 @@ public void setRequestHandlerWhenNullThenIllegalStateException() {
 
 	@Test
 	public void onAuthenticationWhenCustomRequestHandlerThenUsed() {
+		given(this.csrfTokenRepository.loadToken(this.request)).willReturn(this.existingToken);
 		given(this.csrfTokenRepository.loadDeferredToken(this.request, this.response))
 				.willReturn(new TestDeferredCsrfToken(this.existingToken, false));
 
 		CsrfTokenRequestHandler requestHandler = mock(CsrfTokenRequestHandler.class);
 		this.strategy.setRequestHandler(requestHandler);
 		this.strategy.onAuthentication(new TestingAuthenticationToken("user", "password", "ROLE_USER"), this.request,
 				this.response);
+		verify(this.csrfTokenRepository).loadToken(this.request);
+		verify(this.csrfTokenRepository).loadDeferredToken(this.request, this.response);
 		verify(requestHandler).handle(eq(this.request), eq(this.response), any());
 		verifyNoMoreInteractions(requestHandler);
 	}
 
 	@Test
 	public void logoutRemovesCsrfTokenAndLoadsNewDeferredCsrfToken() {
+		given(this.csrfTokenRepository.loadToken(this.request)).willReturn(this.existingToken);
 		given(this.csrfTokenRepository.loadDeferredToken(this.request, this.response))
 				.willReturn(new TestDeferredCsrfToken(this.generatedToken, false));
 		this.strategy.onAuthentication(new TestingAuthenticationToken("user", "password", "ROLE_USER"), this.request,
 				this.response);
+		verify(this.csrfTokenRepository).loadToken(this.request);
 		verify(this.csrfTokenRepository).saveToken(null, this.request, this.response);
 		verify(this.csrfTokenRepository).loadDeferredToken(this.request, this.response);
 		// SEC-2404, SEC-2832
@@ -113,6 +119,7 @@ public void logoutRemovesCsrfTokenAndLoadsNewDeferredCsrfToken() {
 	@Test
 	public void delaySavingCsrf() {
 		this.strategy = new CsrfAuthenticationStrategy(new LazyCsrfTokenRepository(this.csrfTokenRepository));
+		given(this.csrfTokenRepository.loadToken(this.request)).willReturn(this.existingToken, (CsrfToken) null);
 		given(this.csrfTokenRepository.generateToken(this.request)).willReturn(this.generatedToken);
 		this.strategy.onAuthentication(new TestingAuthenticationToken("user", "password", "ROLE_USER"), this.request,
 				this.response);
@@ -121,7 +128,7 @@ public void delaySavingCsrf() {
 				any(HttpServletResponse.class));
 		CsrfToken tokenInRequest = (CsrfToken) this.request.getAttribute(CsrfToken.class.getName());
 		tokenInRequest.getToken();
-		verify(this.csrfTokenRepository).loadToken(this.request);
+		verify(this.csrfTokenRepository, times(2)).loadToken(this.request);
 		verify(this.csrfTokenRepository).generateToken(this.request);
 		verify(this.csrfTokenRepository).saveToken(eq(this.generatedToken), any(HttpServletRequest.class),
 				any(HttpServletResponse.class));