Add MethodExpressionAuthorizationManager

Closes gh-11493

core/src/main/java/org/springframework/security/authorization/ExpressionAuthorizationDecision.java

@@ -0,0 +1,46 @@
+/*
+ * Copyright 2002-2021 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.security.authorization;
+
+import org.springframework.expression.Expression;
+
+/**
+ * Represents an {@link AuthorizationDecision} based on a {@link Expression}
+ *
+ * @author Marcus Da Coregio
+ * @since 5.6
+ */
+public class ExpressionAuthorizationDecision extends AuthorizationDecision {
+
+	private final Expression expression;
+
+	public ExpressionAuthorizationDecision(boolean granted, Expression expressionAttribute) {
+		super(granted);
+		this.expression = expressionAttribute;
+	}
+
+	public Expression getExpression() {
+		return this.expression;
+	}
+
+	@Override
+	public String toString() {
+		return getClass().getSimpleName() + " [" + "granted=" + isGranted() + ", expressionAttribute=" + this.expression
+				+ ']';
+	}
+
+}

core/src/main/java/org/springframework/security/authorization/method/MethodExpressionAuthorizationManager.java

@@ -16,6 +16,72 @@
 
 package org.springframework.security.authorization.method;
 
-public class MethodExpressionAuthorizationManager {
+import java.util.function.Supplier;
+
+import org.aopalliance.intercept.MethodInvocation;
+
+import org.springframework.expression.EvaluationContext;
+import org.springframework.expression.Expression;
+import org.springframework.security.access.expression.ExpressionUtils;
+import org.springframework.security.access.expression.SecurityExpressionHandler;
+import org.springframework.security.access.expression.method.DefaultMethodSecurityExpressionHandler;
+import org.springframework.security.authorization.AuthorizationDecision;
+import org.springframework.security.authorization.AuthorizationManager;
+import org.springframework.security.authorization.ExpressionAuthorizationDecision;
+import org.springframework.security.core.Authentication;
+import org.springframework.util.Assert;
+
+/**
+ * An expression-based {@link AuthorizationManager} that determines the access by
+ * evaluating the provided expression against the {@link MethodInvocation}.
+ *
+ * @author Josh Cummings
+ * @since 5.8
+ */
+public final class MethodExpressionAuthorizationManager implements AuthorizationManager<MethodInvocation> {
+
+	private SecurityExpressionHandler<MethodInvocation> expressionHandler = new DefaultMethodSecurityExpressionHandler();
+
+	private Expression expression;
+
+	/**
+	 * Creates an instance.
+	 * @param expressionString the raw expression string to parse
+	 */
+	public MethodExpressionAuthorizationManager(String expressionString) {
+		Assert.hasText(expressionString, "expressionString cannot be empty");
+		this.expression = this.expressionHandler.getExpressionParser().parseExpression(expressionString);
+	}
+
+	/**
+	 * Sets the {@link SecurityExpressionHandler} to be used. The default is
+	 * {@link DefaultMethodSecurityExpressionHandler}.
+	 * @param expressionHandler the {@link SecurityExpressionHandler} to use
+	 */
+	public void setExpressionHandler(SecurityExpressionHandler<MethodInvocation> expressionHandler) {
+		Assert.notNull(expressionHandler, "expressionHandler cannot be null");
+		this.expressionHandler = expressionHandler;
+		this.expression = expressionHandler.getExpressionParser()
+				.parseExpression(this.expression.getExpressionString());
+	}
+
+	/**
+	 * Determines the access by evaluating the provided expression.
+	 * @param authentication the {@link Supplier} of the {@link Authentication} to check
+	 * @param context the {@link MethodInvocation} to check
+	 * @return an {@link ExpressionAuthorizationDecision} based on the evaluated
+	 * expression
+	 */
+	@Override
+	public AuthorizationDecision check(Supplier<Authentication> authentication, MethodInvocation context) {
+		EvaluationContext ctx = this.expressionHandler.createEvaluationContext(authentication, context);
+		boolean granted = ExpressionUtils.evaluateAsBoolean(this.expression, ctx);
+		return new ExpressionAuthorizationDecision(granted, this.expression);
+	}
+
+	@Override
+	public String toString() {
+		return "WebExpressionAuthorizationManager[expression='" + this.expression + "']";
+	}
 
 }

core/src/test/java/org/springframework/security/authorization/method/MethodExpressionAuthorizationManagerTests.java

@@ -0,0 +1,104 @@
+/*
+ * Copyright 2002-2022 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.security.authorization.method;
+
+import org.junit.jupiter.api.Test;
+import org.junit.platform.commons.util.ReflectionUtils;
+
+import org.springframework.expression.Expression;
+import org.springframework.expression.ExpressionParser;
+import org.springframework.security.access.annotation.BusinessService;
+import org.springframework.security.access.expression.method.DefaultMethodSecurityExpressionHandler;
+import org.springframework.security.authentication.TestAuthentication;
+import org.springframework.security.authorization.AuthorizationDecision;
+import org.springframework.security.util.SimpleMethodInvocation;
+
+import static org.assertj.core.api.Assertions.assertThat;
+import static org.assertj.core.api.Assertions.assertThatIllegalArgumentException;
+import static org.mockito.BDDMockito.given;
+import static org.mockito.Mockito.mock;
+import static org.mockito.Mockito.verify;
+
+class MethodExpressionAuthorizationManagerTests {
+
+	@Test
+	void instantiateWhenExpressionStringNullThenIllegalArgumentException() {
+		assertThatIllegalArgumentException().isThrownBy(() -> new MethodExpressionAuthorizationManager(null))
+				.withMessage("expressionString cannot be empty");
+	}
+
+	@Test
+	void instantiateWhenExpressionStringEmptyThenIllegalArgumentException() {
+		assertThatIllegalArgumentException().isThrownBy(() -> new MethodExpressionAuthorizationManager(""))
+				.withMessage("expressionString cannot be empty");
+	}
+
+	@Test
+	void instantiateWhenExpressionStringBlankThenIllegalArgumentException() {
+		assertThatIllegalArgumentException().isThrownBy(() -> new MethodExpressionAuthorizationManager(" "))
+				.withMessage("expressionString cannot be empty");
+	}
+
+	@Test
+	void instantiateWhenExpressionHandlerNotSetThenDefaultUsed() {
+		MethodExpressionAuthorizationManager manager = new MethodExpressionAuthorizationManager("hasRole('ADMIN')");
+		assertThat(manager).extracting("expressionHandler").isInstanceOf(DefaultMethodSecurityExpressionHandler.class);
+	}
+
+	@Test
+	void setExpressionHandlerWhenNullThenIllegalArgumentException() {
+		MethodExpressionAuthorizationManager manager = new MethodExpressionAuthorizationManager("hasRole('ADMIN')");
+		assertThatIllegalArgumentException().isThrownBy(() -> manager.setExpressionHandler(null))
+				.withMessage("expressionHandler cannot be null");
+	}
+
+	@Test
+	void setExpressionHandlerWhenNotNullThenVerifyExpressionHandler() {
+		String expressionString = "hasRole('ADMIN')";
+		MethodExpressionAuthorizationManager manager = new MethodExpressionAuthorizationManager(expressionString);
+		DefaultMethodSecurityExpressionHandler expressionHandler = new DefaultMethodSecurityExpressionHandler();
+		ExpressionParser mockExpressionParser = mock(ExpressionParser.class);
+		Expression mockExpression = mock(Expression.class);
+		given(mockExpressionParser.parseExpression(expressionString)).willReturn(mockExpression);
+		expressionHandler.setExpressionParser(mockExpressionParser);
+		manager.setExpressionHandler(expressionHandler);
+		assertThat(manager).extracting("expressionHandler").isEqualTo(expressionHandler);
+		assertThat(manager).extracting("expression").isEqualTo(mockExpression);
+		verify(mockExpressionParser).parseExpression(expressionString);
+	}
+
+	@Test
+	void checkWhenExpressionHasRoleAdminConfiguredAndRoleAdminThenGrantedDecision() {
+		MethodExpressionAuthorizationManager manager = new MethodExpressionAuthorizationManager("hasRole('ADMIN')");
+		AuthorizationDecision decision = manager.check(TestAuthentication::authenticatedAdmin,
+				new SimpleMethodInvocation(new Object(),
+						ReflectionUtils.getRequiredMethod(BusinessService.class, "someAdminMethod")));
+		assertThat(decision).isNotNull();
+		assertThat(decision.isGranted()).isTrue();
+	}
+
+	@Test
+	void checkWhenExpressionHasRoleAdminConfiguredAndRoleUserThenDeniedDecision() {
+		MethodExpressionAuthorizationManager manager = new MethodExpressionAuthorizationManager("hasRole('ADMIN')");
+		AuthorizationDecision decision = manager.check(TestAuthentication::authenticatedUser,
+				new SimpleMethodInvocation(new Object(),
+						ReflectionUtils.getRequiredMethod(BusinessService.class, "someAdminMethod")));
+		assertThat(decision).isNotNull();
+		assertThat(decision.isGranted()).isFalse();
+	}
+
+}