Backport NoSchemaIntrospectionCustomRule from graphql@15.2.0

This rule is adapted from graphql/graphql-js#2600
and should be replaced once using graphql >=15.2.0.

Co-authored by: dzucconi <mail@damonzucconi.com>

.env.example

@@ -14,7 +14,7 @@ DIFFUSION_API_BASE=https://diffusion-staging.artsy.net/api
 DIFFUSION_TOKEN=REPLACE
 EMBEDLY_ENDPOINT=https://i.embed.ly/1/display
 EMBEDLY_KEY=REPLACE
-ENABLE_APOLLO=true
+ENABLE_APOLLO=false
 ENABLE_CONSIGNMENTS_STITCHING=true
 ENABLE_QUERY_TRACING=false
 ENABLE_REQUEST_LOGGING=true
@@ -37,6 +37,7 @@ GRAVITY_SECRET=REPLACE
 HMAC_SECRET=https://www.youtube.com/watch?v=F5bAa6gFvLs
 IMPULSE_API_BASE=https://impulse-staging.artsy.net/api
 IMPULSE_APPLICATION_ID=REPLACE
+INTROSPECT_TOKEN=replaceme
 KAWS_API_BASE=https://kaws-staging.artsy.net
 MEMCACHED_URL=localhost:11211
 NODE_ENV=development

src/config.ts

@@ -56,6 +56,7 @@ const {
   HMAC_SECRET,
   IMPULSE_API_BASE,
   IMPULSE_APPLICATION_ID,
+  INTROSPECT_TOKEN,
   IP_BLACKLIST,
   LOG_QUERY_DETAILS_THRESHOLD,
   MEMCACHED_MAX_POOL,
@@ -186,6 +187,7 @@ export default {
   HMAC_SECRET: HMAC_SECRET as string,
   IMPULSE_API_BASE,
   IMPULSE_APPLICATION_ID,
+  INTROSPECT_TOKEN,
   IP_BLACKLIST: IP_BLACKLIST || "",
   LOG_QUERY_DETAILS_THRESHOLD,
   MEMCACHED_MAX_POOL: Number(MEMCACHED_MAX_POOL) || 10,

src/index.ts

@@ -33,6 +33,7 @@ import { ErrorExtension } from "./extensions/errorExtension"
 import { LoggingExtension } from "./extensions/loggingExtension"
 import { principalFieldDirectiveExtension } from "./extensions/principalFieldDirectiveExtension"
 import { principalFieldDirectiveValidation } from "validations/principalFieldDirectiveValidation"
+import { NoSchemaIntrospectionCustomRule } from "validations/noSchemaIntrospectionCustomRule"
 import * as Sentry from "@sentry/node"
 
 const {
@@ -44,6 +45,7 @@ const {
   RESOLVER_TIMEOUT_MS,
   SENTRY_PRIVATE_DSN,
   ENABLE_APOLLO,
+  INTROSPECT_TOKEN,
 } = config
 
 const enableSentry = !!SENTRY_PRIVATE_DSN
@@ -220,7 +222,17 @@ function startApp(appSchema, path: string) {
           userAgent,
         }
 
-        const validationRules = [principalFieldDirectiveValidation]
+        const validationRules = [
+          principalFieldDirectiveValidation,
+
+          // require Authorization header for introspection (in production if configured)
+          ...(PRODUCTION_ENV &&
+          INTROSPECT_TOKEN &&
+          req.headers["authorization"] !== `Bearer ${INTROSPECT_TOKEN}`
+            ? [NoSchemaIntrospectionCustomRule]
+            : []),
+        ]
+
         if (QUERY_DEPTH_LIMIT)
           validationRules.push(depthLimit(QUERY_DEPTH_LIMIT))
 

src/validations/noSchemaIntrospectionCustomRule.ts

@@ -0,0 +1,41 @@
+import {
+  ASTVisitor,
+  GraphQLError,
+  FieldNode,
+  ValidationContext,
+  getNamedType,
+  isIntrospectionType,
+} from "graphql"
+
+// Adapted from https://github.com/graphql/graphql-js/pull/2600.
+// TODO: replace once using graphql >=15.2.0
+
+/**
+ * Prohibit introspection queries
+ *
+ * A GraphQL document is only valid if all fields selected are not fields that
+ * return an introspection type.
+ *
+ * Note: This rule is optional and is not part of the Validation section of the
+ * GraphQL Specification. This rule effectively disables introspection, which
+ * does not reflect best practices and should only be done if absolutely necessary.
+ */
+export const NoSchemaIntrospectionCustomRule = (
+  context: ValidationContext
+): ASTVisitor => {
+  return {
+    Field(node: FieldNode) {
+      const contextType = context.getType()
+      if (!contextType) return
+      const type = getNamedType(contextType)
+      if (type && isIntrospectionType(type)) {
+        context.reportError(
+          new GraphQLError(
+            `GraphQL introspection has been disabled, but the requested query contained the field "${node.name.value}".`,
+            node
+          )
+        )
+      }
+    },
+  }
+}

src/validations/principalFieldDirectiveValidation.ts

@@ -1,6 +1,6 @@
-import { GraphQLError, BREAK } from "graphql"
+import { GraphQLError, BREAK, ASTVisitor } from "graphql"
 
-export const principalFieldDirectiveValidation = (context) => {
+export const principalFieldDirectiveValidation = (context): ASTVisitor => {
   let directivesSeen = 0
   return {
     Directive(node) {