fix: limit the nesting depth in JSONML

Limit the XML nesting depth for CVE-2022-45688 when using the JsonML transform.

src/main/java/org/json/JSONML.java

@@ -27,7 +27,32 @@ public class JSONML {
         XMLTokener x,
         boolean    arrayForm,
         JSONArray  ja,
-        boolean keepStrings
+        boolean keepStrings,
+        int currentNestingDepth
+    ) throws JSONException {
+        return parse(x,arrayForm, ja,
+            keepStrings ? XMLtoJSONMLParserConfiguration.KEEP_STRINGS : XMLtoJSONMLParserConfiguration.ORIGINAL,
+            currentNestingDepth);
+    }
+
+    /**
+     * Parse XML values and store them in a JSONArray.
+     * @param x       The XMLTokener containing the source string.
+     * @param arrayForm true if array form, false if object form.
+     * @param ja      The JSONArray that is containing the current tag or null
+     *     if we are at the outermost level.
+     * @param config  The XML parser configuration:
+     *     XMLtoJSONMLParserConfiguration.ORIGINAL is the default behaviour;
+     *     XMLtoJSONMLParserConfiguration.KEEP_STRINGS means Don't type-convert text nodes and attribute values.
+     * @return A JSONArray if the value is the outermost tag, otherwise null.
+     * @throws JSONException if a parsing error occurs
+     */
+    private static Object parse(
+        XMLTokener x,
+        boolean    arrayForm,
+        JSONArray  ja,
+        XMLtoJSONMLParserConfiguration config,
+        int currentNestingDepth
     ) throws JSONException {
         String     attribute;
         char       c;
@@ -152,7 +177,7 @@ public class JSONML {
                             if (!(token instanceof String)) {
                                 throw x.syntaxError("Missing value");
                             }
-                            newjo.accumulate(attribute, keepStrings ? ((String)token) :XML.stringToValue((String)token));
+                            newjo.accumulate(attribute, config.isKeepStrings() ? ((String)token) :XML.stringToValue((String)token));
                             token = null;
                         } else {
                             newjo.accumulate(attribute, "");
@@ -181,7 +206,12 @@ public class JSONML {
                         if (token != XML.GT) {
                             throw x.syntaxError("Misshaped tag");
                         }
-                        closeTag = (String)parse(x, arrayForm, newja, keepStrings);
+
+                        if (currentNestingDepth == config.getMaxNestingDepth()) {
+                            throw x.syntaxError("Maximum nesting depth of " + config.getMaxNestingDepth() + " reached");
+                        }
+
+                        closeTag = (String)parse(x, arrayForm, newja, config, currentNestingDepth + 1);
                         if (closeTag != null) {
                             if (!closeTag.equals(tagName)) {
                                 throw x.syntaxError("Mismatched '" + tagName +
@@ -203,7 +233,7 @@ public class JSONML {
             } else {
                 if (ja != null) {
                     ja.put(token instanceof String
-                        ? keepStrings ? XML.unescape((String)token) :XML.stringToValue((String)token)
+                        ? (config.isKeepStrings() ? XML.unescape((String)token) : XML.stringToValue((String)token))
                         : token);
                 }
             }
@@ -224,7 +254,7 @@ public class JSONML {
      * @throws JSONException Thrown on error converting to a JSONArray
      */
     public static JSONArray toJSONArray(String string) throws JSONException {
-        return (JSONArray)parse(new XMLTokener(string), true, null, false);
+        return (JSONArray)parse(new XMLTokener(string), true, null, XMLtoJSONMLParserConfiguration.ORIGINAL, 0);
     }
 
 
@@ -235,8 +265,8 @@ public class JSONML {
      * attributes, then the second element will be JSONObject containing the
      * name/value pairs. If the tag contains children, then strings and
      * JSONArrays will represent the child tags.
-     * As opposed to toJSONArray this method does not attempt to convert 
+     * As opposed to toJSONArray this method does not attempt to convert
-     * any text node or attribute value to any type 
+     * any text node or attribute value to any type
      * but just leaves it as a string.
      * Comments, prologs, DTDs, and <pre>{@code &lt;[ [ ]]>}</pre> are ignored.
      * @param string The source string.
@@ -246,7 +276,7 @@ public class JSONML {
      * @throws JSONException Thrown on error converting to a JSONArray
      */
     public static JSONArray toJSONArray(String string, boolean keepStrings) throws JSONException {
-        return (JSONArray)parse(new XMLTokener(string), true, null, keepStrings);
+        return (JSONArray)parse(new XMLTokener(string), true, null, keepStrings, 0);
     }
 
 
@@ -257,8 +287,8 @@ public class JSONML {
      * attributes, then the second element will be JSONObject containing the
      * name/value pairs. If the tag contains children, then strings and
      * JSONArrays will represent the child content and tags.
-     * As opposed to toJSONArray this method does not attempt to convert 
+     * As opposed to toJSONArray this method does not attempt to convert
-     * any text node or attribute value to any type 
+     * any text node or attribute value to any type
      * but just leaves it as a string.
      * Comments, prologs, DTDs, and <pre>{@code &lt;[ [ ]]>}</pre> are ignored.
      * @param x An XMLTokener.
@@ -268,7 +298,7 @@ public class JSONML {
      * @throws JSONException Thrown on error converting to a JSONArray
      */
     public static JSONArray toJSONArray(XMLTokener x, boolean keepStrings) throws JSONException {
-        return (JSONArray)parse(x, true, null, keepStrings);
+        return (JSONArray)parse(x, true, null, keepStrings, 0);
     }
 
 
@@ -285,7 +315,7 @@ public class JSONML {
      * @throws JSONException Thrown on error converting to a JSONArray
      */
     public static JSONArray toJSONArray(XMLTokener x) throws JSONException {
-        return (JSONArray)parse(x, true, null, false);
+        return (JSONArray)parse(x, true, null, false, 0);
     }
 
 
@@ -303,10 +333,10 @@ public class JSONML {
      * @throws JSONException Thrown on error converting to a JSONObject
      */
     public static JSONObject toJSONObject(String string) throws JSONException {
-        return (JSONObject)parse(new XMLTokener(string), false, null, false);
+        return (JSONObject)parse(new XMLTokener(string), false, null, false, 0);
     }
-    
+
-    
+
     /**
      * Convert a well-formed (but not necessarily valid) XML string into a
      * JSONObject using the JsonML transform. Each XML tag is represented as
@@ -323,10 +353,32 @@ public class JSONML {
      * @throws JSONException Thrown on error converting to a JSONObject
      */
     public static JSONObject toJSONObject(String string, boolean keepStrings) throws JSONException {
-        return (JSONObject)parse(new XMLTokener(string), false, null, keepStrings);
+        return (JSONObject)parse(new XMLTokener(string), false, null, keepStrings, 0);
     }
 
-    
+
+    /**
+     * Convert a well-formed (but not necessarily valid) XML string into a
+     * JSONObject using the JsonML transform. Each XML tag is represented as
+     * a JSONObject with a "tagName" property. If the tag has attributes, then
+     * the attributes will be in the JSONObject as properties. If the tag
+     * contains children, the object will have a "childNodes" property which
+     * will be an array of strings and JsonML JSONObjects.
+
+     * Comments, prologs, DTDs, and <pre>{@code &lt;[ [ ]]>}</pre> are ignored.
+     * @param string The XML source text.
+     * @param config  The XML parser configuration:
+     *     XMLtoJSONMLParserConfiguration.ORIGINAL is the default behaviour;
+     *     XMLtoJSONMLParserConfiguration.KEEP_STRINGS means values will not be coerced into boolean
+     *       or numeric values and will instead be left as strings
+     * @return A JSONObject containing the structured data from the XML string.
+     * @throws JSONException Thrown on error converting to a JSONObject
+     */
+    public static JSONObject toJSONObject(String string, XMLtoJSONMLParserConfiguration config) throws JSONException {
+        return (JSONObject)parse(new XMLTokener(string), false, null, config, 0);
+    }
+
+
     /**
      * Convert a well-formed (but not necessarily valid) XML string into a
      * JSONObject using the JsonML transform. Each XML tag is represented as
@@ -341,7 +393,7 @@ public class JSONML {
      * @throws JSONException Thrown on error converting to a JSONObject
      */
     public static JSONObject toJSONObject(XMLTokener x) throws JSONException {
-           return (JSONObject)parse(x, false, null, false);
+           return (JSONObject)parse(x, false, null, false, 0);
     }
 
 
@@ -361,7 +413,29 @@ public class JSONML {
      * @throws JSONException Thrown on error converting to a JSONObject
      */
     public static JSONObject toJSONObject(XMLTokener x, boolean keepStrings) throws JSONException {
-           return (JSONObject)parse(x, false, null, keepStrings);
+           return (JSONObject)parse(x, false, null, keepStrings, 0);
+    }
+
+
+    /**
+     * Convert a well-formed (but not necessarily valid) XML string into a
+     * JSONObject using the JsonML transform. Each XML tag is represented as
+     * a JSONObject with a "tagName" property. If the tag has attributes, then
+     * the attributes will be in the JSONObject as properties. If the tag
+     * contains children, the object will have a "childNodes" property which
+     * will be an array of strings and JsonML JSONObjects.
+
+     * Comments, prologs, DTDs, and <pre>{@code &lt;[ [ ]]>}</pre> are ignored.
+     * @param x An XMLTokener of the XML source text.
+     * @param config  The XML parser configuration:
+     *     XMLtoJSONMLParserConfiguration.ORIGINAL is the default behaviour;
+     *     XMLtoJSONMLParserConfiguration.KEEP_STRINGS means values will not be coerced into boolean
+     *       or numeric values and will instead be left as strings
+     * @return A JSONObject containing the structured data from the XML string.
+     * @throws JSONException Thrown on error converting to a JSONObject
+     */
+    public static JSONObject toJSONObject(XMLTokener x, XMLtoJSONMLParserConfiguration config) throws JSONException {
+        return (JSONObject)parse(x, false, null, config, 0);
     }
 
 
@@ -442,6 +516,7 @@ public class JSONML {
         return sb.toString();
     }
 
+
     /**
      * Reverse the JSONML transformation, making an XML text from a JSONObject.
      * The JSONObject must contain a "tagName" property. If it has children,

src/main/java/org/json/XMLtoJSONMLParserConfiguration.java

@@ -0,0 +1,128 @@
+package org.json;
+/*
+Public Domain.
+*/
+
+/**
+ * Configuration object for the XML to JSONML parser. The configuration is immutable.
+ */
+@SuppressWarnings({""})
+public class XMLtoJSONMLParserConfiguration {
+    /**
+     * Used to indicate there's no defined limit to the maximum nesting depth when parsing a XML
+     * document to JSONML.
+     */
+    public static final int UNDEFINED_MAXIMUM_NESTING_DEPTH = -1;
+
+    /**
+     * The default maximum nesting depth when parsing a XML document to JSONML.
+     */
+    public static final int DEFAULT_MAXIMUM_NESTING_DEPTH = 512;
+
+    /** Original Configuration of the XML to JSONML Parser. */
+    public static final XMLtoJSONMLParserConfiguration ORIGINAL
+        = new XMLtoJSONMLParserConfiguration();
+    /** Original configuration of the XML to JSONML Parser except that values are kept as strings. */
+    public static final XMLtoJSONMLParserConfiguration KEEP_STRINGS
+        = new XMLtoJSONMLParserConfiguration().withKeepStrings(true);
+
+    /**
+     * When parsing the XML into JSONML, specifies if values should be kept as strings (<code>true</code>), or if
+     * they should try to be guessed into JSON values (numeric, boolean, string)
+     */
+    private boolean keepStrings;
+
+    /**
+     * The maximum nesting depth when parsing a XML document to JSONML.
+     */
+    private int maxNestingDepth = DEFAULT_MAXIMUM_NESTING_DEPTH;
+
+    /**
+     * Default parser configuration. Does not keep strings (tries to implicitly convert values).
+     */
+    public XMLtoJSONMLParserConfiguration() {
+        this.keepStrings = false;
+    }
+
+    /**
+     * Configure the parser string processing and use the default CDATA Tag Name as "content".
+     * @param keepStrings <code>true</code> to parse all values as string.
+     *      <code>false</code> to try and convert XML string values into a JSON value.
+     * @param maxNestingDepth <code>int</code> to limit the nesting depth
+     */
+    public XMLtoJSONMLParserConfiguration(final boolean keepStrings, final int maxNestingDepth) {
+        this.keepStrings = keepStrings;
+        this.maxNestingDepth = maxNestingDepth;
+    }
+
+    /**
+     * Provides a new instance of the same configuration.
+     */
+    @Override
+    protected XMLtoJSONMLParserConfiguration clone() {
+        // future modifications to this method should always ensure a "deep"
+        // clone in the case of collections. i.e. if a Map is added as a configuration
+        // item, a new map instance should be created and if possible each value in the
+        // map should be cloned as well. If the values of the map are known to also
+        // be immutable, then a shallow clone of the map is acceptable.
+        return new XMLtoJSONMLParserConfiguration(
+                this.keepStrings,
+                this.maxNestingDepth
+        );
+    }
+
+    /**
+     * When parsing the XML into JSONML, specifies if values should be kept as strings (<code>true</code>), or if
+     * they should try to be guessed into JSON values (numeric, boolean, string)
+     *
+     * @return The <code>keepStrings</code> configuration value.
+     */
+    public boolean isKeepStrings() {
+        return this.keepStrings;
+    }
+
+    /**
+     * When parsing the XML into JSONML, specifies if values should be kept as strings (<code>true</code>), or if
+     * they should try to be guessed into JSON values (numeric, boolean, string)
+     *
+     * @param newVal
+     *      new value to use for the <code>keepStrings</code> configuration option.
+     *
+     * @return The existing configuration will not be modified. A new configuration is returned.
+     */
+    public XMLtoJSONMLParserConfiguration withKeepStrings(final boolean newVal) {
+        XMLtoJSONMLParserConfiguration newConfig = this.clone();
+        newConfig.keepStrings = newVal;
+        return newConfig;
+    }
+
+    /**
+     * The maximum nesting depth that the parser will descend before throwing an exception
+     * when parsing the XML into JSONML.
+     * @return the maximum nesting depth set for this configuration
+     */
+    public int getMaxNestingDepth() {
+        return maxNestingDepth;
+    }
+
+    /**
+     * Defines the maximum nesting depth that the parser will descend before throwing an exception
+     * when parsing the XML into JSONML. The default max nesting depth is 512, which means the parser
+     * will throw a JsonException if the maximum depth is reached.
+     * Using any negative value as a parameter is equivalent to setting no limit to the nesting depth,
+     * which means the parses will go as deep as the maximum call stack size allows.
+     * @param maxNestingDepth the maximum nesting depth allowed to the XML parser
+     * @return The existing configuration will not be modified. A new configuration is returned.
+     */
+    public XMLtoJSONMLParserConfiguration withMaxNestingDepth(int maxNestingDepth) {
+        XMLtoJSONMLParserConfiguration newConfig = this.clone();
+
+        if (maxNestingDepth > UNDEFINED_MAXIMUM_NESTING_DEPTH) {
+            newConfig.maxNestingDepth = maxNestingDepth;
+        } else {
+            newConfig.maxNestingDepth = UNDEFINED_MAXIMUM_NESTING_DEPTH;
+        }
+
+        return newConfig;
+    }
+}

src/test/java/org/json/junit/JSONMLTest.java

@@ -11,19 +11,19 @@ import org.junit.Test;
 
 /**
  * Tests for org.json.JSONML.java
- * 
+ *
  * Certain inputs are expected to result in exceptions. These tests are
  * executed first. JSONML provides an API to:
- *     Convert an XML string into a JSONArray or a JSONObject. 
+ *     Convert an XML string into a JSONArray or a JSONObject.
  *     Convert a JSONArray or JSONObject into an XML string.
  * Both fromstring and tostring operations operations should be symmetrical
- * within the limits of JSONML. 
+ * within the limits of JSONML.
  * It should be possible to perform the following operations, which should
  * result in the original string being recovered, within the limits of the
  * underlying classes:
  *  Convert a string -> JSONArray -> string -> JSONObject -> string
  *  Convert a string -> JSONObject -> string -> JSONArray -> string
- * 
+ *
  */
 public class JSONMLTest {
 
@@ -56,7 +56,7 @@ public class JSONMLTest {
 
     /**
      * Attempts to call JSONML.toString() with a null JSONArray.
-     * Expects a NullPointerException. 
+     * Expects a NullPointerException.
      */
     @Test(expected=NullPointerException.class)
     public void nullJSONXMLException() {
@@ -69,7 +69,7 @@ public class JSONMLTest {
 
     /**
      * Attempts to call JSONML.toString() with a null JSONArray.
-     * Expects a JSONException. 
+     * Expects a JSONException.
      */
     @Test
     public void emptyJSONXMLException() {
@@ -125,7 +125,7 @@ public class JSONMLTest {
             "[\"addresses\","+
                 "{\"xsi:noNamespaceSchemaLocation\":\"test.xsd\","+
                     "\"xmlns:xsi\":\"http://www.w3.org/2001/XMLSchema-instance\"},"+
-                // this array has no name 
+                // this array has no name
                 "["+
                     "[\"name\"],"+
                     "[\"nocontent\"],"+
@@ -180,7 +180,7 @@ public class JSONMLTest {
     }
 
     /**
-     * Attempts to transform a malformed XML document 
+     * Attempts to transform a malformed XML document
      * (element tag has a frontslash) to a JSONArray.\
      * Expects a JSONException
      */
@@ -191,7 +191,7 @@ public class JSONMLTest {
          * In this case, the XML is invalid because the 'name' element
          * contains an invalid frontslash.
          */
-        String xmlStr = 
+        String xmlStr =
             "<?xml version=\"1.0\" encoding=\"UTF-8\"?>\n"+
             "<addresses xmlns:xsi=\"http://www.w3.org/2001/XMLSchema-instance\""+
             "   xsi:noNamespaceSchemaLocation='test.xsd'>\n"+
@@ -216,7 +216,7 @@ public class JSONMLTest {
      */
     @Test
     public void invalidBangInTagException() {
-        String xmlStr = 
+        String xmlStr =
             "<?xml version=\"1.0\" encoding=\"UTF-8\"?>\n"+
             "<addresses xmlns:xsi=\"http://www.w3.org/2001/XMLSchema-instance\""+
             "   xsi:noNamespaceSchemaLocation='test.xsd'>\n"+
@@ -246,7 +246,7 @@ public class JSONMLTest {
          * In this case, the XML is invalid because an element
          * starts with '!' and has no closing tag
          */
-        String xmlStr = 
+        String xmlStr =
             "<?xml version=\"1.0\" encoding=\"UTF-8\"?>\n"+
             "<addresses xmlns:xsi=\"http://www.w3.org/2001/XMLSchema-instance\""+
             "   xsi:noNamespaceSchemaLocation='test.xsd'>\n"+
@@ -276,7 +276,7 @@ public class JSONMLTest {
          * In this case, the XML is invalid because an element
          * has no closing '>'.
          */
-        String xmlStr = 
+        String xmlStr =
             "<?xml version=\"1.0\" encoding=\"UTF-8\"?>\n"+
             "<addresses xmlns:xsi=\"http://www.w3.org/2001/XMLSchema-instance\""+
             "   xsi:noNamespaceSchemaLocation='test.xsd'>\n"+
@@ -306,7 +306,7 @@ public class JSONMLTest {
          * In this case, the XML is invalid because an element
          * has no name after the closing tag '</'.
          */
-        String xmlStr = 
+        String xmlStr =
             "<?xml version=\"1.0\" encoding=\"UTF-8\"?>\n"+
             "<addresses xmlns:xsi=\"http://www.w3.org/2001/XMLSchema-instance\""+
             "   xsi:noNamespaceSchemaLocation='test.xsd'>\n"+
@@ -336,7 +336,7 @@ public class JSONMLTest {
          * In this case, the XML is invalid because an element
          * has '>' after the closing tag '</' and name.
          */
-        String xmlStr = 
+        String xmlStr =
             "<?xml version=\"1.0\" encoding=\"UTF-8\"?>\n"+
             "<addresses xmlns:xsi=\"http://www.w3.org/2001/XMLSchema-instance\""+
             "   xsi:noNamespaceSchemaLocation=\"test.xsd\">\n"+
@@ -364,9 +364,9 @@ public class JSONMLTest {
         /**
          * xmlStr contains XML text which is transformed into a JSONArray.
          * In this case, the XML is invalid because an element
-         * does not have a complete CDATA string. 
+         * does not have a complete CDATA string.
          */
-        String xmlStr = 
+        String xmlStr =
             "<?xml version=\"1.0\" encoding=\"UTF-8\"?>\n"+
             "<addresses xmlns:xsi=\"http://www.w3.org/2001/XMLSchema-instance\""+
             "   xsi:noNamespaceSchemaLocation='test.xsd'>\n"+
@@ -388,7 +388,7 @@ public class JSONMLTest {
     /**
      * Convert an XML document into a JSONArray, then use JSONML.toString()
      * to convert it into a string. This string is then converted back into
-     * a JSONArray. Both JSONArrays are compared against a control to 
+     * a JSONArray. Both JSONArrays are compared against a control to
      * confirm the contents.
      */
     @Test
@@ -405,7 +405,7 @@ public class JSONMLTest {
          * which is used to create a final JSONArray, which is also compared
          * against the expected JSONArray.
          */
-        String xmlStr = 
+        String xmlStr =
             "<?xml version=\"1.0\" encoding=\"UTF-8\"?>\n"+
             "<addresses xmlns:xsi=\"http://www.w3.org/2001/XMLSchema-instance\""+
                  "xsi:noNamespaceSchemaLocation='test.xsd'>\n"+
@@ -414,7 +414,7 @@ public class JSONMLTest {
                      "<nocontent/>>\n"+
                  "</address>\n"+
             "</addresses>";
-        String expectedStr = 
+        String expectedStr =
             "[\"addresses\","+
                 "{\"xsi:noNamespaceSchemaLocation\":\"test.xsd\","+
                     "\"xmlns:xsi\":\"http://www.w3.org/2001/XMLSchema-instance\"},"+
@@ -434,12 +434,12 @@ public class JSONMLTest {
     }
 
     /**
-     * Convert an XML document into a JSONObject. Use JSONML.toString() to 
+     * Convert an XML document into a JSONObject. Use JSONML.toString() to
      * convert it back into a string, and then re-convert it into a JSONObject.
      * Both JSONObjects are compared against a control JSONObject to confirm
      * the contents.
      * <p>
-     * Next convert the XML document into a JSONArray. Use JSONML.toString() to 
+     * Next convert the XML document into a JSONArray. Use JSONML.toString() to
      * convert it back into a string, and then re-convert it into a JSONArray.
      * Both JSONArrays are compared against a control JSONArray to confirm
      * the contents.
@@ -452,23 +452,23 @@ public class JSONMLTest {
         /**
          * xmlStr contains XML text which is transformed into a JSONObject,
          * restored to XML, transformed into a JSONArray, and then restored
-         * to XML again. Both JSONObject and JSONArray should contain the same 
+         * to XML again. Both JSONObject and JSONArray should contain the same
          * information and should produce the same XML, allowing for non-ordered
          * attributes.
-         * 
+         *
          * Transformation to JSONObject:
          *      The elementName is stored as a string where key="tagName"
          *      Attributes are simply stored as key/value pairs
          *      If the element has either content or child elements, they are stored
          *      in a jsonArray with key="childNodes".
-         * 
+         *
          * Transformation to JSONArray:
          *      1st entry = elementname
          *      2nd entry = attributes object (if present)
          *      3rd entry = content (if present)
          *      4th entry = child element JSONArrays (if present)
          */
-        String xmlStr = 
+        String xmlStr =
             "<?xml version=\"1.0\" encoding=\"UTF-8\"?>\n"+
             "<addresses xmlns:xsi=\"http://www.w3.org/2001/XMLSchema-instance\""+
                 "xsi:noNamespaceSchemaLocation='test.xsd'>\n"+
@@ -585,7 +585,7 @@ public class JSONMLTest {
                 "\"tagName\":\"addresses\""+
             "}";
 
-        String expectedJSONArrayStr = 
+        String expectedJSONArrayStr =
             "["+
                 "\"addresses\","+
                 "{"+
@@ -645,12 +645,12 @@ public class JSONMLTest {
         JSONObject finalJsonObject = JSONML.toJSONObject(jsonObjectXmlToStr);
         Util.compareActualVsExpectedJsonObjects(finalJsonObject, expectedJsonObject);
 
-        // create a JSON array from the original string and make sure it 
+        // create a JSON array from the original string and make sure it
         // looks as expected
         JSONArray jsonArray = JSONML.toJSONArray(xmlStr);
         JSONArray expectedJsonArray = new JSONArray(expectedJSONArrayStr);
         Util.compareActualVsExpectedJsonArrays(jsonArray,expectedJsonArray);
-    
+
         // restore the XML, then make another JSONArray and make sure it
         // looks as expected
         String jsonArrayXmlToStr = JSONML.toString(jsonArray);
@@ -668,14 +668,14 @@ public class JSONMLTest {
      * Convert an XML document which contains embedded comments into
      * a JSONArray. Use JSONML.toString() to turn it into a string, then
      * reconvert it into a JSONArray. Compare both JSONArrays to a control
-     * JSONArray to confirm the contents. 
+     * JSONArray to confirm the contents.
      * <p>
      * This test shows how XML comments are handled.
      */
     @Test
     public void commentsInXML() {
 
-        String xmlStr = 
+        String xmlStr =
             "<?xml version=\"1.0\" encoding=\"UTF-8\"?>\n"+
             "<!-- this is a comment -->\n"+
             "<addresses>\n"+
@@ -734,7 +734,7 @@ public class JSONMLTest {
         final String expectedJsonString = "[\"root\",[\"id\",\"01\"],[\"id\",\"1\"],[\"id\",\"00\"],[\"id\",\"0\"],[\"item\",{\"id\":\"01\"}],[\"title\",\"True\"]]";
         final JSONArray json = JSONML.toJSONArray(originalXml,true);
         assertEquals(expectedJsonString, json.toString());
-        
+
         final String reverseXml = JSONML.toString(json);
         assertEquals(originalXml, reverseXml);
     }
@@ -749,7 +749,7 @@ public class JSONMLTest {
         final String revertedXml = JSONML.toString(jsonArray);
         assertEquals(revertedXml, originalXml);
     }
-    
+
     /**
      * JSON string cannot be reverted to original xml. See test result in
      * comment below.
@@ -770,7 +770,7 @@ public class JSONMLTest {
 // 1. Our XML parser does not handle generic HTML entities, only valid XML entities. Hence &nbsp;
 //     or other HTML specific entities would fail on reversability
 // 2. Our JSON implementation for storing the XML attributes uses the standard unordered map.
-//     This means that <tag attr1="v1" attr2="v2" /> can not be reversed reliably.  
+//     This means that <tag attr1="v1" attr2="v2" /> can not be reversed reliably.
 //
 //    /**
 //     * Test texts taken from jsonml.org. Currently our implementation FAILS this conversion but shouldn't.
@@ -783,13 +783,13 @@ public class JSONMLTest {
 //        final String expectedJsonString = "[\"table\",{\"class\" : \"MyTable\",\"style\" : \"background-color:yellow\"},[\"tr\",[\"td\",{\"class\" : \"MyTD\",\"style\" : \"border:1px solid black\"},\"#550758\"],[\"td\",{\"class\" : \"MyTD\",\"style\" : \"background-color:red\"},\"Example text here\"]],[\"tr\",[\"td\",{\"class\" : \"MyTD\",\"style\" : \"border:1px solid black\"},\"#993101\"],[\"td\",{\"class\" : \"MyTD\",\"style\" : \"background-color:green\"},\"127624015\"]],[\"tr\",[\"td\",{\"class\" : \"MyTD\",\"style\" : \"border:1px solid black\"},\"#E33D87\"],[\"td\",{\"class\" : \"MyTD\",\"style\" : \"background-color:blue\"},\"\u00A0\",[\"span\",{ \"style\" : \"background-color:maroon\" },\"\u00A9\"],\"\u00A0\"]]]";
 //        final JSONArray json = JSONML.toJSONArray(originalXml,true);
 //        final String actualJsonString = json.toString();
-//        
+//
 //        final String reverseXml = JSONML.toString(json);
 //        assertNotEquals(originalXml, reverseXml);
 //
 //        assertNotEquals(expectedJsonString, actualJsonString);
 //    }
-//    
+//
 //    /**
 //     * Test texts taken from jsonml.org but modified to have XML entities only.
 //     */
@@ -799,15 +799,15 @@ public class JSONMLTest {
 //        final String expectedJsonString = "[\"table\",{\"class\" : \"MyTable\",\"style\" : \"background-color:yellow\"},[\"tr\",[\"td\",{\"class\" : \"MyTD\",\"style\" : \"border:1px solid black\"},\"#550758\"],[\"td\",{\"class\" : \"MyTD\",\"style\" : \"background-color:red\"},\"Example text here\"]],[\"tr\",[\"td\",{\"class\" : \"MyTD\",\"style\" : \"border:1px solid black\"},\"#993101\"],[\"td\",{\"class\" : \"MyTD\",\"style\" : \"background-color:green\"},\"127624015\"]],[\"tr\",[\"td\",{\"class\" : \"MyTD\",\"style\" : \"border:1px solid black\"},\"#E33D87\"],[\"td\",{\"class\" : \"MyTD\",\"style\" : \"background-color:blue\"},\"&\",[\"span\",{ \"style\" : \"background-color:maroon\" },\">\"],\"<\"]]]";
 //        final JSONArray jsonML = JSONML.toJSONArray(originalXml,true);
 //        final String actualJsonString = jsonML.toString();
-//        
+//
 //        final String reverseXml = JSONML.toString(jsonML);
 //        // currently not equal because the hashing of the attribute objects makes the attribute
-//        // order not happen the same way twice 
+//        // order not happen the same way twice
 //        assertEquals(originalXml, reverseXml);
 //
 //        assertEquals(expectedJsonString, actualJsonString);
 //    }
-    
+
     @Test (timeout = 6000)
     public void testIssue484InfinteLoop1() {
         try {
@@ -819,11 +819,11 @@ public class JSONMLTest {
                     ex.getMessage());
         }
     }
-    
+
     @Test (timeout = 6000)
     public void testIssue484InfinteLoop2() {
         try {
-            String input = "??*\n" + 
+            String input = "??*\n" +
                     "??|?CglR??`??>?w??PIlr??D?$?-?o??O?*??{OD?Y??`2a????NM?bq?:O?>S$?J?B.gUK?m\b??zE???!v]?
???
???c??????h???s???g???`?qbi??:Zl?)?}1^??k?0??:$V?$?Ovs(}J??????2;gQ?
???Tg?K?`?h%c?hmGA?<!C*?9?~?t?)??,zA???S}?Q??.q?j????]";
          JSONML.toJSONObject(input);
             fail("Exception expected for invalid JSON.");
@@ -833,4 +833,64 @@ public class JSONMLTest {
                     ex.getMessage());
         }
     }
+
+    @Test
+    public void testMaxNestingDepthOf42IsRespected() {
+        final String wayTooLongMalformedXML = new String(new char[6000]).replace("\0", "<a>");
+
+        final int maxNestingDepth = 42;
+
+        try {
+            JSONML.toJSONObject(wayTooLongMalformedXML, XMLtoJSONMLParserConfiguration.ORIGINAL.withMaxNestingDepth(maxNestingDepth));
+
+            fail("Expecting a JSONException");
+        } catch (JSONException e) {
+            assertTrue("Wrong throwable thrown: not expecting message <" + e.getMessage() + ">",
+                e.getMessage().startsWith("Maximum nesting depth of " + maxNestingDepth));
+        }
+    }
+
+    @Test
+    public void testMaxNestingDepthIsRespectedWithValidXML() {
+        final String perfectlyFineXML = "<Test>\n" +
+            "  <employee>\n" +
+            "    <name>sonoo</name>\n" +
+            "    <salary>56000</salary>\n" +
+            "    <married>true</married>\n" +
+            "  </employee>\n" +
+            "</Test>\n";
+
+        final int maxNestingDepth = 1;
+
+        try {
+            JSONML.toJSONObject(perfectlyFineXML, XMLtoJSONMLParserConfiguration.ORIGINAL.withMaxNestingDepth(maxNestingDepth));
+
+            fail("Expecting a JSONException");
+        } catch (JSONException e) {
+            assertTrue("Wrong throwable thrown: not expecting message <" + e.getMessage() + ">",
+                e.getMessage().startsWith("Maximum nesting depth of " + maxNestingDepth));
+        }
+    }
+
+    @Test
+    public void testMaxNestingDepthWithValidFittingXML() {
+        final String perfectlyFineXML = "<Test>\n" +
+            "  <employee>\n" +
+            "    <name>sonoo</name>\n" +
+            "    <salary>56000</salary>\n" +
+            "    <married>true</married>\n" +
+            "  </employee>\n" +
+            "</Test>\n";
+
+        final int maxNestingDepth = 3;
+
+        try {
+            JSONML.toJSONObject(perfectlyFineXML, XMLtoJSONMLParserConfiguration.ORIGINAL.withMaxNestingDepth(maxNestingDepth));
+        } catch (JSONException e) {
+            e.printStackTrace();
+            fail("XML document should be parsed as its maximum depth fits the maxNestingDepth " +
+                "parameter of the XMLtoJSONMLParserConfiguration used");
+        }
+    }
+
 }