OpenAPI/Swagger routes loader and request/response validator (#150)

Author: maximthomas

openig-core/pom.xml

@@ -14,7 +14,7 @@
 
   Copyright 2010-2011 ApexIdentity Inc.
   Portions Copyright 2011-2016 ForgeRock AS.
-  Portions copyright 2025 3A Systems LLC.
+  Portions copyright 2025-2026 3A Systems LLC.
 -->
 <project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
   <modelVersion>4.0.0</modelVersion>
@@ -161,6 +161,13 @@
 		<groupId>commons-io</groupId>
 		<artifactId>commons-io</artifactId>
 	</dependency>
+    <dependency>
+      <groupId>com.atlassian.oai</groupId>
+      <artifactId>swagger-request-validator-core</artifactId>
+      <version>2.46.0</version>
+    </dependency>
+
+    <!-- test dependencies -->
     <dependency>
       <groupId>org.glassfish.grizzly</groupId>
       <artifactId>grizzly-http-server</artifactId>

openig-core/src/main/java/org/forgerock/openig/alias/CoreClassAliasResolver.java

@@ -36,6 +36,7 @@
 import org.forgerock.openig.filter.HeaderFilter;
 import org.forgerock.openig.filter.HttpBasicAuthFilter;
 import org.forgerock.openig.filter.LocationHeaderFilter;
+import org.forgerock.openig.filter.OpenApiValidationFilter;
 import org.forgerock.openig.filter.PasswordReplayFilterHeaplet;
 import org.forgerock.openig.filter.ScriptableFilter;
 import org.forgerock.openig.filter.SqlAttributesFilter;
@@ -101,6 +102,7 @@ public class CoreClassAliasResolver implements ClassAliasResolver {
         ALIASES.put("KeyStore", KeyStoreHeaplet.class);
         ALIASES.put("LocationHeaderFilter", LocationHeaderFilter.class);
         ALIASES.put("MappedThrottlingPolicy", MappedThrottlingPolicyHeaplet.class);
+        ALIASES.put("OpenApiValidationFilter", OpenApiValidationFilter.class);
         ALIASES.put("PasswordReplayFilter", PasswordReplayFilterHeaplet.class);
         ALIASES.put("Router", RouterHandler.class);
         ALIASES.put("RouterHandler", RouterHandler.class);

openig-core/src/main/java/org/forgerock/openig/el/Functions.java

@@ -13,6 +13,7 @@
  *
  * Copyright 2010-2011 ApexIdentity Inc.
  * Portions Copyright 2011-2016 ForgeRock AS.
+ * Portions Copyright 2026 3A Systems LLC.
  */
 
 package org.forgerock.openig.el;
@@ -33,6 +34,7 @@
 import java.util.regex.Pattern;
 import java.util.regex.PatternSyntaxException;
 
+import org.apache.commons.lang3.StringEscapeUtils;
 import org.forgerock.http.util.Uris;
 import org.forgerock.openig.util.StringUtil;
 import org.forgerock.util.encode.Base64;
@@ -441,4 +443,14 @@ public static String fileToUrl(File file) {
         }
     }
 
+    /**
+     * Escapes the characters in a {@code String} using JSON string rules.
+     *
+     * @param value the string to escape, may be null
+     * @return a JSON escaped string
+     */
+    public static String escapeJson(String value) {
+        return StringEscapeUtils.escapeJson(value);
+    }
+
 }

openig-core/src/main/java/org/forgerock/openig/filter/OpenApiValidationFilter.java

@@ -0,0 +1,273 @@
+/*
+ * The contents of this file are subject to the terms of the Common Development and
+ * Distribution License (the License). You may not use this file except in compliance with the
+ * License.
+ *
+ * You can obtain a copy of the License at legal/CDDLv1.0.txt. See the License for the
+ * specific language governing permission and limitations under the License.
+ *
+ * When distributing Covered Software, include this CDDL Header Notice in each file and include
+ * the License file at legal/CDDLv1.0.txt. If applicable, add the following below the CDDL
+ * Header, with the fields enclosed by brackets [] replaced by your own identifying
+ * information: "Portions copyright [year] [name of copyright owner]".
+ *
+ * Copyright 2026 3A Systems LLC.
+ */
+
+package org.forgerock.openig.filter;
+
+import com.atlassian.oai.validator.OpenApiInteractionValidator;
+import com.atlassian.oai.validator.model.SimpleRequest;
+import com.atlassian.oai.validator.model.SimpleResponse;
+import com.atlassian.oai.validator.report.ValidationReport;
+import org.apache.http.NameValuePair;
+import org.apache.http.client.utils.URLEncodedUtils;
+import org.forgerock.http.Filter;
+import org.forgerock.http.Handler;
+import org.forgerock.http.protocol.Request;
+import org.forgerock.http.protocol.Response;
+import org.forgerock.http.protocol.Status;
+import org.forgerock.json.JsonValue;
+import org.forgerock.openig.heap.GenericHeaplet;
+import org.forgerock.openig.heap.HeapException;
+import org.forgerock.services.context.AttributesContext;
+import org.forgerock.services.context.Context;
+import org.forgerock.util.promise.NeverThrowsException;
+import org.forgerock.util.promise.Promise;
+import org.forgerock.util.promise.Promises;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+import java.io.IOException;
+import java.nio.charset.StandardCharsets;
+import java.util.List;
+import java.util.Map;
+import java.util.concurrent.ExecutionException;
+import java.util.stream.Collectors;
+
+import static org.forgerock.openig.util.JsonValues.optionalHeapObject;
+
+/**
+ * Validates HTTP requests and responses against an
+ * OpenAPI (Swagger 2.x / OpenAPI 3.x) specification
+ *
+ * <h2>Request validation</h2>
+ * <p>If the request fails validation the filter stops processing and delegates to
+ * {@code requestValidationErrorHandler} instead of forwarding the request downstream.
+ * The default {@code requestValidationErrorHandler} returns {@code 400 Bad Request}.</p>
+ *
+ * <h2>Response validation</h2>
+ * <p>After the downstream handler returns a response, the filter validates it against the spec.
+ * Behaviour depends on {@code failOnResponseViolation}:
+ * <ul>
+ *   <li>{@code true} – delegate to {@code responseValidationErrorHandler}.  The default returns
+ *       {@code 503 Service Unavailable}</li>
+ *   <li>{@code false} (default) – log a warning and pass the original response through.</li>
+ * </ul>
+ * </p>
+ *
+ * <h2>Heap configuration</h2>
+ * <pre>{@code
+ * {
+ *   "name": "myValidator",
+ *   "type": "OpenApiValidationFilter",
+ *   "config": {
+ *     "specFile": "/path/to/openapi.yaml",
+ *     "failOnResponseViolation": false,
+ *     "requestValidationErrorHandler": "403BadRequest",
+ *     "responseValidationErrorHandler": "503ServiceUnavailable"
+ *   }
+ * }
+ * }</pre>
+ */
+public class OpenApiValidationFilter implements Filter {
+
+    /**
+     * Key under which the {@link ValidationReport} is stored in the
+     * {@link AttributesContext} before delegating to an error handler.
+     */
+    public static final String ATTR_OPENAPI_VALIDATION_REPORT = "openApiValidationReport";
+
+    private static final Logger logger = LoggerFactory.getLogger(OpenApiValidationFilter.class);
+
+    private final OpenApiInteractionValidator validator;
+
+    private final boolean failOnResponseViolation;
+
+    private final Handler requestValidationErrorHandler;
+
+    private final Handler responseValidationErrorHandler;
+
+    /**
+     * Creates a filter backed by a pre-built {@link OpenApiInteractionValidator}.
+     *
+     * @param spec                    The OpenAPI / Swagger specification to use in the validator
+     * @param failOnResponseViolation if {@code true}, a response validation failure results in
+     *                               a {@code 503} error; if {@code false}, it is only logged
+     * @param requestValidationErrorHandler       handler invoked on request validation failure
+     * @param responseValidationErrorHandler       handler invoked on response validation failure when
+     *                                {@code failOnResponseViolation} is {@code true}
+     */
+    private OpenApiValidationFilter(String spec, boolean failOnResponseViolation,
+                                    Handler requestValidationErrorHandler, Handler responseValidationErrorHandler) {
+        this(OpenApiInteractionValidator.createForInlineApiSpecification(spec).build(), failOnResponseViolation,
+                requestValidationErrorHandler, responseValidationErrorHandler);
+    }
+
+    OpenApiValidationFilter(OpenApiInteractionValidator validator, boolean failOnResponseViolation) {
+        this(validator, failOnResponseViolation,
+                defaultRequestValidationErrorHandler(), defaultResponseValidationErrorHandler());
+    }
+
+    OpenApiValidationFilter(OpenApiInteractionValidator validator, boolean failOnResponseViolation,
+                            Handler requestValidationErrorHandler, Handler responseValidationErrorHandler) {
+        this.validator = validator;
+        this.failOnResponseViolation = failOnResponseViolation;
+        this.requestValidationErrorHandler = requestValidationErrorHandler;
+        this.responseValidationErrorHandler = responseValidationErrorHandler;
+    }
+
+    @Override
+    public Promise<Response, NeverThrowsException> filter(Context context, Request request, Handler next) {
+
+        final SimpleRequest validatorRequest;
+        try {
+            validatorRequest = validatorRequestOf(request);
+        } catch (IOException e) {
+            logger.error("exception while reading the request", e);
+            return Promises.newResultPromise(new Response(Status.INTERNAL_SERVER_ERROR));
+        }
+
+        final ValidationReport requestReport = validator.validateRequest(validatorRequest);
+        if (requestReport.hasErrors()) {
+
+            logger.info("Request validation failed for {} {}: {}",
+                    request.getMethod(), request.getUri(), requestReport);
+            return requestValidationErrorHandler.handle(injectReportToContext(context, requestReport), request);
+        }
+
+        return next.handle(context, request).then(response -> {
+            final com.atlassian.oai.validator.model.Response validatorResponse;
+            try {
+                validatorResponse = validatorResponseOf(response);
+            } catch (IOException e) {
+                logger.error("exception while reading the response", e);
+                return new Response(Status.INTERNAL_SERVER_ERROR);
+            }
+
+            ValidationReport responseValidationReport
+                    = validator.validateResponse(validatorRequest.getPath(), validatorRequest.getMethod(), validatorResponse);
+            if(responseValidationReport.hasErrors()) {
+                logger.warn("upstream response does not match specification: {}", responseValidationReport);
+                if(failOnResponseViolation) {
+                    try {
+                        return responseValidationErrorHandler.handle(
+                                injectReportToContext(context, responseValidationReport), request)
+                                .get();
+                    } catch (InterruptedException | ExecutionException e) {
+                        logger.error("exception while handling the response", e);
+                        return new Response(Status.INTERNAL_SERVER_ERROR);
+                    }
+                }
+            }
+            return response;
+        });
+    }
+
+    private static Context injectReportToContext(final Context parent, final ValidationReport report) {
+        Context context = parent;
+        if(!parent.containsContext(AttributesContext.class)) {
+            context = new AttributesContext(parent);
+        }
+        context.asContext(AttributesContext.class).getAttributes().put(ATTR_OPENAPI_VALIDATION_REPORT, report.getMessages());
+        return context;
+    }
+
+    private static Response buildErrorResponse(final Status status, final String body) {
+        final Response response = new Response(status);
+        response.getHeaders().put("Content-Type", "text/plain; charset=UTF-8");
+        response.setEntity(body);
+        return response;
+    }
+
+    private static SimpleRequest validatorRequestOf(final Request request) throws IOException {
+        SimpleRequest.Builder builder = new SimpleRequest.Builder(request.getMethod(), request.getUri().getPath());
+        if(request.getEntity().getBytes().length > 0) {
+            builder.withBody(request.getEntity().getBytes());
+        }
+
+        if (request.getHeaders() != null) {
+            request.getHeaders().asMapOfHeaders().forEach((key, value) -> builder.withHeader(key, value.getValues()));
+            if(request.getEntity().getBytes().length > 0
+                    && request.getHeaders().keySet().stream().noneMatch(k -> k.equalsIgnoreCase("Content-Type"))) {
+                builder.withHeader("Content-Type", "application/json");
+            }
+        }
+
+        List<NameValuePair> params = URLEncodedUtils.parse(request.getUri().asURI(), StandardCharsets.UTF_8);
+
+        Map<String, List<String>> paramsMap = params.stream()
+                .collect(Collectors.groupingBy(
+                        NameValuePair::getName,
+                        Collectors.mapping(NameValuePair::getValue, Collectors.toList())
+                ));
+        paramsMap.forEach(builder::withQueryParam);
+
+        return builder.build();
+    }
+
+    private static SimpleResponse validatorResponseOf(final Response response) throws IOException {
+        final SimpleResponse.Builder builder = new SimpleResponse.Builder(response.getStatus().getCode());
+        if(response.getEntity().getBytes().length > 0) {
+            builder.withBody(response.getEntity().getBytes());
+        }
+
+        if (response.getHeaders() != null) {
+            response.getHeaders().asMapOfHeaders().forEach((key, value) -> builder.withHeader(key, value.getValues()));
+            if(response.getEntity().getBytes().length > 0
+                    && response.getHeaders().keySet().stream().noneMatch(k -> k.equalsIgnoreCase("Content-Type"))) {
+                builder.withHeader("Content-Type", "application/json");
+            }
+        }
+        return builder.build();
+    }
+
+    public static Handler defaultRequestValidationErrorHandler() {
+        return (context, request) ->
+                Promises.newResultPromise(buildErrorResponse(Status.BAD_REQUEST,
+                        "Request validation failed: " + context.asContext(AttributesContext.class)
+                                .getAttributes().get(ATTR_OPENAPI_VALIDATION_REPORT).toString()));
+    }
+
+    public static Handler defaultResponseValidationErrorHandler() {
+        return (context, request) ->
+                Promises.newResultPromise(buildErrorResponse(Status.SERVICE_UNAVAILABLE,
+                        "Response validation failed: " + context.asContext(AttributesContext.class)
+                                .getAttributes().get(ATTR_OPENAPI_VALIDATION_REPORT).toString()));
+    }
+
+    public static class Heaplet extends GenericHeaplet {
+
+        @Override
+        public Object create() throws HeapException {
+
+            JsonValue evaluatedConfig = config.as(evaluatedWithHeapProperties());
+            final String openApiSpec = evaluatedConfig.get("spec").required().asString();
+
+            final boolean failOnResponseViolation =
+                    evaluatedConfig.get("failOnResponseViolation").defaultTo(false).asBoolean();
+
+            Handler requestValidationErrorHandler = config.get("requestValidationErrorHandler")
+                    .as(optionalHeapObject(heap, Handler.class));
+            requestValidationErrorHandler = requestValidationErrorHandler == null ? defaultRequestValidationErrorHandler() : requestValidationErrorHandler;
+
+            Handler responseValidationErrorHandler = config.get("responseValidationErrorHandler")
+                    .as(optionalHeapObject(heap, Handler.class));
+            responseValidationErrorHandler = responseValidationErrorHandler == null ? defaultResponseValidationErrorHandler() : responseValidationErrorHandler;
+
+            return new OpenApiValidationFilter(openApiSpec, failOnResponseViolation,
+                    requestValidationErrorHandler, responseValidationErrorHandler);
+
+        }
+    }
+}

openig-core/src/main/java/org/forgerock/openig/handler/router/DirectoryMonitor.java

@@ -12,6 +12,7 @@
  * information: "Portions copyright [year] [name of copyright owner]".
  *
  * Copyright 2014-2016 ForgeRock AS.
+ * Portions copyright 2026 3A Systems LLC
  */
 
 package org.forgerock.openig.handler.router;
@@ -85,7 +86,7 @@ class DirectoryMonitor {
      *         a non-{@literal null} directory (it may or may not exists) to monitor
      */
     public DirectoryMonitor(final File directory) {
-        this(directory, new HashMap<File, Long>());
+        this(directory, new HashMap<>());
     }
 
     /**
@@ -177,15 +178,14 @@ FileChangeSet createFileChangeSet() {
     /**
      * Factory method to be used as a fluent {@link FileFilter} declaration.
      *
-     * @return a filter for {@literal .json} files
+     * @return a filter for {@literal .json and .yaml} files
      */
     private static FileFilter jsonFiles() {
-        return new FileFilter() {
-            @Override
-            public boolean accept(final File path) {
-                return path.isFile() && path.getName().endsWith(".json");
-            }
-        };
+        return path -> path.isFile() && (
+                path.getName().endsWith(".json")
+                        || path.getName().endsWith(".yaml")
+                        || path.getName().endsWith(".yml")
+        );
     }
 
     void store(String routeId, JsonValue routeConfig) throws IOException {