graphql-java · dondonz · Mar 19, 2024 · Mar 18, 2024 · Mar 18, 2024 · Mar 18, 2024
diff --git a/src/main/java/graphql/execution/AsyncExecutionStrategy.java b/src/main/java/graphql/execution/AsyncExecutionStrategy.java
@@ -5,8 +5,10 @@
 import graphql.execution.instrumentation.ExecutionStrategyInstrumentationContext;
 import graphql.execution.instrumentation.Instrumentation;
 import graphql.execution.instrumentation.parameters.InstrumentationExecutionStrategyParameters;
+import graphql.introspection.Introspection;
 
 import java.util.List;
+import java.util.Optional;
 import java.util.concurrent.CompletableFuture;
 import java.util.function.BiConsumer;
 
@@ -44,6 +46,12 @@ public CompletableFuture<ExecutionResult> execute(ExecutionContext executionCont
 
         MergedSelectionSet fields = parameters.getFields();
         List<String> fieldNames = fields.getKeys();
+
+        Optional<ExecutionResult> isNotSensible = Introspection.isIntrospectionSensible(fields, executionContext);
+        if (isNotSensible.isPresent()) {
+            return CompletableFuture.completedFuture(isNotSensible.get());
+        }
+
         Async.CombinedBuilder<FieldValueInfo> futures = Async.ofExpectedSize(fields.size());
         for (String fieldName : fieldNames) {
             MergedField currentField = fields.getSubField(fieldName);

diff --git a/src/main/java/graphql/execution/AsyncSerialExecutionStrategy.java b/src/main/java/graphql/execution/AsyncSerialExecutionStrategy.java
@@ -6,8 +6,10 @@
 import graphql.execution.instrumentation.Instrumentation;
 import graphql.execution.instrumentation.InstrumentationContext;
 import graphql.execution.instrumentation.parameters.InstrumentationExecutionStrategyParameters;
+import graphql.introspection.Introspection;
 
 import java.util.List;
+import java.util.Optional;
 import java.util.concurrent.CompletableFuture;
 
 import static graphql.execution.instrumentation.SimpleInstrumentationContext.nonNullCtx;
@@ -39,6 +41,13 @@ public CompletableFuture<ExecutionResult> execute(ExecutionContext executionCont
         MergedSelectionSet fields = parameters.getFields();
         ImmutableList<String> fieldNames = ImmutableList.copyOf(fields.keySet());
 
+        // this is highly unlikely since Mutations cant do introspection BUT in theory someone could make the query strategy this code
+        // so belts and braces
+        Optional<ExecutionResult> isNotSensible = Introspection.isIntrospectionSensible(fields, executionContext);
+        if (isNotSensible.isPresent()) {
+            return CompletableFuture.completedFuture(isNotSensible.get());
+        }
+
         CompletableFuture<List<ExecutionResult>> resultsFuture = Async.eachSequentially(fieldNames, (fieldName, index, prevResults) -> {
             MergedField currentField = fields.getSubField(fieldName);
             ResultPath fieldPath = parameters.getPath().segment(mkNameForPath(currentField));

diff --git a/src/main/java/graphql/introspection/GoodFaithIntrospection.java b/src/main/java/graphql/introspection/GoodFaithIntrospection.java
@@ -0,0 +1,124 @@
+package graphql.introspection;
+
+import com.google.common.collect.ImmutableList;
+import com.google.common.collect.ImmutableListMultimap;
+import graphql.ErrorClassification;
+import graphql.ExecutionResult;
+import graphql.GraphQLContext;
+import graphql.GraphQLError;
+import graphql.PublicApi;
+import graphql.execution.ExecutionContext;
+import graphql.language.SourceLocation;
+import graphql.normalized.ExecutableNormalizedField;
+import graphql.normalized.ExecutableNormalizedOperation;
+import graphql.schema.FieldCoordinates;
+
+import java.util.HashMap;
+import java.util.List;
+import java.util.Map;
+import java.util.Optional;
+import java.util.concurrent.atomic.AtomicBoolean;
+
+import static graphql.schema.FieldCoordinates.coordinates;
+
+/**
+ * This {@link graphql.execution.instrumentation.Instrumentation} ensure that a submitted introspection query is done in
+ * good faith.
+ * <p>
+ * There are attack vectors where a crafted introspection query can cause the engine to spend too much time
+ * producing introspection data.  This is especially true on large schemas with lots of types and fields.
+ * <p>
+ * Schemas form a cyclic graph and hence it's possible to send in introspection queries that can reference those cycles
+ * and in large schemas this can be expensive and perhaps a "denial of service".
+ * <p>
+ * This instrumentation only allows one __schema field or one __type field to be present, and it does not allow the `__Type` fields
+ * to form a cycle, i.e., that can only be present once.  This allows the standard and common introspection queries to work
+ * so tooling such as graphiql can work.
+ */
+@PublicApi
+public class GoodFaithIntrospection {
+
+    /**
+     * Placing a boolean value under this key in the per request {@link GraphQLContext} will enable
+     * or disable Good Faith Introspection on that request.
+     */
+    public static final String GOOD_FAITH_INTROSPECTION_DISABLED = "GOOD_FAITH_INTROSPECTION_DISABLED";
+
+    private static final AtomicBoolean ENABLED_STATE = new AtomicBoolean(true);
+
+    /**
+     * @return true if good faith introspection is enabled
+     */
+    public static boolean isEnabledJvmWide() {
+        return ENABLED_STATE.get();
+    }
+
+    /**
+     * This allows you to disable good faith introspection, which is on by default.
+     *
+     * @param flag the desired state
+     *
+     * @return the previous state
+     */
+    public static boolean enabledJvmWide(boolean flag) {
+        return ENABLED_STATE.getAndSet(flag);
+    }
+
+    private static final Map<FieldCoordinates, Integer> ALLOWED_FIELD_INSTANCES = new HashMap<>();
+
+    static {
+        ALLOWED_FIELD_INSTANCES.put(coordinates("Query", "__schema"), 1);
+        ALLOWED_FIELD_INSTANCES.put(coordinates("Query", "__type"), 1);
+        ALLOWED_FIELD_INSTANCES.put(coordinates("__Type", "fields"), 1);
+        ALLOWED_FIELD_INSTANCES.put(coordinates("__Type", "inputFields"), 1);
+        ALLOWED_FIELD_INSTANCES.put(coordinates("__Type", "interfaces"), 1);
+        ALLOWED_FIELD_INSTANCES.put(coordinates("__Type", "possibleTypes"), 1);
+    }
+
+    public static Optional<ExecutionResult> checkIntrospection(ExecutionContext executionContext) {
+        if (isIntrospectionEnabled(executionContext.getGraphQLContext())) {
+            ExecutableNormalizedOperation operation = executionContext.getNormalizedQueryTree().get();
+            ImmutableListMultimap<FieldCoordinates, ExecutableNormalizedField> coordinatesToENFs = operation.getCoordinatesToNormalizedFields();
+            for (Map.Entry<FieldCoordinates, Integer> entry : ALLOWED_FIELD_INSTANCES.entrySet()) {
+                FieldCoordinates coordinates = entry.getKey();
+                Integer allowSize = entry.getValue();
+                ImmutableList<ExecutableNormalizedField> normalizedFields = coordinatesToENFs.get(coordinates);
+                if (normalizedFields.size() > allowSize) {
+                    BadFaithIntrospectionError error = new BadFaithIntrospectionError(coordinates.toString());
+                    return Optional.of(ExecutionResult.newExecutionResult().addError(error).build());
+                }
+            }
+        }
+        return Optional.empty();
+    }
+
+    private static boolean isIntrospectionEnabled(GraphQLContext graphQlContext) {
+        if (!isEnabledJvmWide()) {
+            return false;
+        }
+        return !graphQlContext.getOrDefault(GOOD_FAITH_INTROSPECTION_DISABLED, false);
+    }
+
+    public static class BadFaithIntrospectionError implements GraphQLError {
+        private final String message;
+
+        public BadFaithIntrospectionError(String qualifiedField) {
+            this.message = String.format("This request is not asking for introspection in good faith - %s is present too often!", qualifiedField);
+        }
+
+        @Override
+        public String getMessage() {
+            return message;
+        }
+
+        @Override
+        public ErrorClassification getErrorType() {
+            return ErrorClassification.errorClassification("BadFaithIntrospection");
+        }
+
+        @Override
+        public List<SourceLocation> getLocations() {
+            return null;
+        }
+    }
+}
diff --git a/src/main/java/graphql/introspection/Introspection.java b/src/main/java/graphql/introspection/Introspection.java
@@ -3,9 +3,13 @@
 
 import com.google.common.collect.ImmutableSet;
 import graphql.Assert;
+import graphql.ExecutionResult;
 import graphql.GraphQLContext;
 import graphql.Internal;
 import graphql.PublicApi;
+import graphql.execution.ExecutionContext;
+import graphql.execution.MergedField;
+import graphql.execution.MergedSelectionSet;
 import graphql.execution.ValuesResolver;
 import graphql.language.AstPrinter;
 import graphql.schema.FieldCoordinates;
@@ -32,14 +36,17 @@
 import graphql.schema.GraphQLSchema;
 import graphql.schema.GraphQLUnionType;
 import graphql.schema.InputValueWithState;
+import org.jetbrains.annotations.NotNull;
 
 import java.util.ArrayList;
 import java.util.HashSet;
 import java.util.LinkedHashMap;
 import java.util.List;
 import java.util.Locale;
 import java.util.Map;
+import java.util.Optional;
 import java.util.Set;
+import java.util.concurrent.atomic.AtomicBoolean;
 import java.util.function.Function;
 import java.util.stream.Collectors;
 
@@ -58,8 +65,88 @@
 import static graphql.schema.GraphQLTypeUtil.unwrapAllAs;
 import static graphql.schema.GraphQLTypeUtil.unwrapOne;
 
+/**
+ * GraphQl has a unique capability called <a href="https://spec.graphql.org/October2021/#sec-Introspection">Introspection</a> that allow
+ * consumers to inspect the system and discover the fields and types available and makes the system self documented.
+ * <p>
+ * Some security recommendations such as <a href="https://owasp.org/www-chapter-vancouver/assets/presentations/2020-06_GraphQL_Security.pdf">OWASP</a>
+ * recommend that introspection be disabled in production.  The {@link Introspection#enabledJvmWide(boolean)} method can be used to disable
+ * introspection for the whole JVM or you can place {@link Introspection#INTROSPECTION_DISABLED} into the {@link GraphQLContext} of a request
+ * to disable introspection for that request.
+ */
 @PublicApi
 public class Introspection {
+
+
+    /**
+     * Placing a boolean value under this key in the per request {@link GraphQLContext} will enable
+     * or disable Introspection on that request.
+     */
+    public static final String INTROSPECTION_DISABLED = "INTROSPECTION_DISABLED";
+    private static final AtomicBoolean INTROSPECTION_ENABLED_STATE = new AtomicBoolean(true);
+
+    /**
+     * This static method will enable / disable Introspection at a JVM wide level.
+     *
+     * @param enabled the flag indicating the desired enabled state
+     *
+     * @return the previous state of enablement
+     */
+    public static boolean enabledJvmWide(boolean enabled) {
+        return INTROSPECTION_ENABLED_STATE.getAndSet(enabled);
+    }
+
+    /**
+     * @return true if Introspection is enabled at a JVM wide level or false otherwise
+     */
+    public static boolean isEnabledJvmWide() {
+        return INTROSPECTION_ENABLED_STATE.get();
+    }
+
+    /**
+     * This will look in to the field selection set and see if there are introspection fields,
+     * and if there is,it checks if introspection should run, and if not it will return an errored {@link ExecutionResult}
+     * that can be returned to the user.
+     *
+     * @param mergedSelectionSet the fields to be executed
+     * @param executionContext   the execution context in play
+     *
+     * @return an optional error result
+     */
+    public static Optional<ExecutionResult> isIntrospectionSensible(MergedSelectionSet mergedSelectionSet, ExecutionContext executionContext) {
+        GraphQLContext graphQLContext = executionContext.getGraphQLContext();
+        MergedField schemaField = mergedSelectionSet.getSubField(SchemaMetaFieldDef.getName());
+        if (schemaField != null) {
+            if (!isIntrospectionEnabled(graphQLContext)) {
+                return mkDisabledError(schemaField);
+            }
+        }
+        MergedField typeField = mergedSelectionSet.getSubField(TypeMetaFieldDef.getName());
+        if (typeField != null) {
+            if (!isIntrospectionEnabled(graphQLContext)) {
+                return mkDisabledError(typeField);
+            }
+        }
+        if (schemaField != null || typeField != null)
+        {
+            return GoodFaithIntrospection.checkIntrospection(executionContext);
+        }
+        return Optional.empty();
+    }
+
+    @NotNull
+    private static Optional<ExecutionResult> mkDisabledError(MergedField schemaField) {
+        IntrospectionDisabledError error = new IntrospectionDisabledError(schemaField.getSingleField().getSourceLocation());
+        return Optional.of(ExecutionResult.newExecutionResult().addError(error).build());
+    }
+
+    private static boolean isIntrospectionEnabled(GraphQLContext graphQlContext) {
+        if (!isEnabledJvmWide()) {
+            return false;
+        }
+        return !graphQlContext.getOrDefault(INTROSPECTION_DISABLED, false);
+    }
+
     private static final Map<FieldCoordinates, IntrospectionDataFetcher<?>> introspectionDataFetchers = new LinkedHashMap<>();
 
     private static void register(GraphQLFieldsContainer parentType, String fieldName, IntrospectionDataFetcher<?> introspectionDataFetcher) {
@@ -623,6 +710,7 @@ public enum DirectiveLocation {
         return environment.getGraphQLSchema().getType(name);
     };
 
+    // __typename is always available
     public static final IntrospectionDataFetcher<?> TypeNameMetaFieldDefDataFetcher = environment -> simplePrint(environment.getParentType());
 
     @Internal

diff --git a/src/main/java/graphql/introspection/IntrospectionDisabledError.java b/src/main/java/graphql/introspection/IntrospectionDisabledError.java
@@ -0,0 +1,35 @@
+package graphql.introspection;
+
+import graphql.ErrorClassification;
+import graphql.ErrorType;
+import graphql.GraphQLError;
+import graphql.Internal;
+import graphql.language.SourceLocation;
+
+import java.util.Collections;
+import java.util.List;
+
+@Internal
+public class IntrospectionDisabledError implements GraphQLError {
+
+    private final List<SourceLocation> locations;
+
+    public IntrospectionDisabledError(SourceLocation sourceLocation) {
+        locations = sourceLocation == null ? Collections.emptyList() : Collections.singletonList(sourceLocation);
+    }
+
+    @Override
+    public String getMessage() {
+        return "Introspection has been disabled for this request";
+    }
+
+    @Override
+    public List<SourceLocation> getLocations() {
+        return locations;
+    }
+
+    @Override
+    public ErrorClassification getErrorType() {
+        return ErrorClassification.errorClassification("IntrospectionDisabled");
+    }
+}
diff --git a/src/main/java/graphql/schema/visibility/NoIntrospectionGraphqlFieldVisibility.java b/src/main/java/graphql/schema/visibility/NoIntrospectionGraphqlFieldVisibility.java
@@ -12,10 +12,15 @@
  * This field visibility will prevent Introspection queries from being performed.  Technically this puts your
  * system in contravention of <a href="https://spec.graphql.org/October2021/#sec-Introspection">the specification</a>
  * but some production systems want this lock down in place.
+ *
+ * @deprecated This is no longer the best way to prevent Introspection - {@link graphql.introspection.Introspection#enabledJvmWide(boolean)}
+ * can be used instead
  */
 @PublicApi
+@Deprecated // Deprecated since 2024-03-16
 public class NoIntrospectionGraphqlFieldVisibility implements GraphqlFieldVisibility {
 
+    @Deprecated // Deprecated since 2024-03-16
     public static NoIntrospectionGraphqlFieldVisibility NO_INTROSPECTION_FIELD_VISIBILITY = new NoIntrospectionGraphqlFieldVisibility();