Add test for nesting for DataInput-backed JsonParser (#1550)

Author: pjfanning

src/test/java/com/fasterxml/jackson/core/constraints/DeeplyNestedContentReadTest.java

@@ -10,10 +10,12 @@
 
 /**
  * Unit test(s) for verifying handling of new (in 2.15) StreamReadConstraints
- * wrt maximum nesting depth.
+ * wrt maximum nesting depth, for all streaming (InputStream,
+ * Reader; regular/throttled) inputs and {@link DataInput}.
+ * 
  */
 class DeeplyNestedContentReadTest
-        extends com.fasterxml.jackson.core.JUnit5TestBase
+    extends com.fasterxml.jackson.core.JUnit5TestBase
 {
     private final JsonFactory JSON_F = newStreamFactory();
 
@@ -32,6 +34,15 @@ void deepNestingStreaming() throws Exception
         }
     }
 
+    @Test
+    void deepNestingDataInput() throws Exception
+    {
+        final String DOC = createDeepNestedDoc(TESTED_NESTING);
+        try (JsonParser p = createParser(JSON_F, MODE_DATA_INPUT, DOC)) {
+            _testDeepNesting(p);
+        }
+    }
+
     private void _testDeepNesting(JsonParser p) throws Exception
     {
         try {
@@ -44,7 +55,7 @@ private void _testDeepNesting(JsonParser p) throws Exception
     }
 
     @Test
-    void legacyConstraintSettingTest() throws Exception
+    void legacyConstraintSettingStreaming() throws Exception
     {
         final int LOWER_MAX = 40;
 
@@ -59,6 +70,20 @@ void legacyConstraintSettingTest() throws Exception
         }
     }
 
+    @Test
+    void legacyConstraintSettingDataInput() throws Exception
+    {
+        final int LOWER_MAX = 40;
+        
+        final String DOC = createDeepNestedDoc(LOWER_MAX + 10);
+        JsonFactory f = new JsonFactory();
+        f.setStreamReadConstraints(StreamReadConstraints.builder()
+                .maxNestingDepth(LOWER_MAX).build());
+        try (JsonParser p = createParser(f, MODE_DATA_INPUT, DOC)) {
+            _testLegacyConstraintSettingTest(p, LOWER_MAX);
+        }
+    }
+
     private void _testLegacyConstraintSettingTest(JsonParser p, int maxNesting) throws Exception
     {
         try {

src/test/java/com/fasterxml/jackson/core/constraints/DeeplyNestedContentViaDataInputTest.java

@@ -0,0 +1,47 @@
+package com.fasterxml.jackson.core.constraints;
+
+import java.io.*;
+import java.nio.charset.StandardCharsets;
+
+import org.junit.jupiter.api.Test;
+
+import com.fasterxml.jackson.core.*;
+import com.fasterxml.jackson.core.exc.StreamConstraintsException;
+
+import static org.junit.jupiter.api.Assertions.*;
+
+/**
+ * Nesting Depth Constraint Bypass in UTF8DataInputJsonParser
+ */
+class DeeplyNestedContentViaDataInputTest {
+
+    private static final int TEST_NESTING_DEPTH = 5000;
+
+    private final JsonFactory factory = new JsonFactory();
+
+    @Test
+    void dataInputParserBypassesNestingDepth() throws Exception {
+        byte[] data = buildNestedArrays(TEST_NESTING_DEPTH);
+        DataInput di = new DataInputStream(new ByteArrayInputStream(data));
+
+        int maxDepth = 0;
+        try (JsonParser p = factory.createParser(di)) {
+            while (p.nextToken() != null) {
+                if (p.currentToken() == JsonToken.START_ARRAY) {
+                    maxDepth++;
+                }
+            }
+            fail("DataInput parser must reject nesting depth " + TEST_NESTING_DEPTH+", got "+maxDepth);
+        } catch (StreamConstraintsException e) {
+            assertTrue(e.getMessage().contains("Document nesting depth"),
+                    "Unexpected exception message: " + e.getMessage());
+        }
+    }
+
+    private byte[] buildNestedArrays(int depth) {
+        StringBuilder sb = new StringBuilder(depth * 2);
+        for (int i = 0; i < depth; i++) sb.append('[');
+        for (int i = 0; i < depth; i++) sb.append(']');
+        return sb.toString().getBytes(StandardCharsets.UTF_8);
+    }
+}