Prevent object creation when loading YAML files.
When creating a new Yaml instance from SnakeYaml to read in a
configuration file the instance is now configured that no objects are
created automatically.
diff --git a/src/main/java/org/apache/commons/configuration2/YAMLConfiguration.java b/src/main/java/org/apache/commons/configuration2/YAMLConfiguration.java
index 1593d12..2b15d66 100644
--- a/src/main/java/org/apache/commons/configuration2/YAMLConfiguration.java
+++ b/src/main/java/org/apache/commons/configuration2/YAMLConfiguration.java
@@ -18,11 +18,14 @@
package org.apache.commons.configuration2;
import org.apache.commons.configuration2.ex.ConfigurationException;
+import org.apache.commons.configuration2.ex.ConfigurationRuntimeException;
import org.apache.commons.configuration2.io.InputStreamSupport;
import org.apache.commons.configuration2.tree.ImmutableNode;
import org.yaml.snakeyaml.DumperOptions;
import org.yaml.snakeyaml.LoaderOptions;
import org.yaml.snakeyaml.Yaml;
+import org.yaml.snakeyaml.constructor.Constructor;
+import org.yaml.snakeyaml.representer.Representer;
import java.io.IOException;
import java.io.InputStream;
@@ -65,7 +68,7 @@
{
try
{
- final Yaml yaml = new Yaml();
+ final Yaml yaml = createYamlForReading(new LoaderOptions());
final Map<String, Object> map = (Map) yaml.load(in);
load(map);
}
@@ -80,7 +83,7 @@
{
try
{
- final Yaml yaml = new Yaml(options);
+ final Yaml yaml = createYamlForReading(options);
final Map<String, Object> map = (Map) yaml.load(in);
load(map);
}
@@ -117,7 +120,7 @@
{
try
{
- final Yaml yaml = new Yaml();
+ final Yaml yaml = createYamlForReading(new LoaderOptions());
final Map<String, Object> map = (Map) yaml.load(in);
load(map);
}
@@ -132,7 +135,7 @@
{
try
{
- final Yaml yaml = new Yaml(options);
+ final Yaml yaml = createYamlForReading(options);
final Map<String, Object> map = (Map) yaml.load(in);
load(map);
}
@@ -142,4 +145,34 @@
}
}
+ /**
+ * Creates a {@code Yaml} object for reading a Yaml file. The object is
+ * configured with some default settings.
+ *
+ * @param options options for loading the file
+ * @return the {@code Yaml} instance for loading a file
+ */
+ private static Yaml createYamlForReading(LoaderOptions options)
+ {
+ return new Yaml(createClassLoadingDisablingConstructor(), new Representer(), new DumperOptions(), options);
+ }
+
+ /**
+ * Returns a {@code Constructor} object for the YAML parser that prevents
+ * all classes from being loaded. This effectively disables the dynamic
+ * creation of Java objects that are declared in YAML files to be loaded.
+ *
+ * @return the {@code Constructor} preventing object creation
+ */
+ private static Constructor createClassLoadingDisablingConstructor()
+ {
+ return new Constructor()
+ {
+ @Override
+ protected Class<?> getClassForName(String name)
+ {
+ throw new ConfigurationRuntimeException("Class loading is disabled.");
+ }
+ };
+ }
}
diff --git a/src/test/java/org/apache/commons/configuration2/TestYAMLConfiguration.java b/src/test/java/org/apache/commons/configuration2/TestYAMLConfiguration.java
index dbdaea0..0945a30 100644
--- a/src/test/java/org/apache/commons/configuration2/TestYAMLConfiguration.java
+++ b/src/test/java/org/apache/commons/configuration2/TestYAMLConfiguration.java
@@ -17,26 +17,37 @@
package org.apache.commons.configuration2;
-import static org.junit.Assert.assertEquals;
-import static org.junit.Assert.assertTrue;
-
+import java.io.ByteArrayInputStream;
+import java.io.File;
import java.io.FileReader;
import java.io.IOException;
+import java.io.StringReader;
import java.io.StringWriter;
+import java.nio.charset.StandardCharsets;
import java.util.Arrays;
import java.util.List;
import java.util.Map;
import org.apache.commons.configuration2.ex.ConfigurationException;
import org.junit.Before;
+import org.junit.Rule;
import org.junit.Test;
+import org.junit.rules.TemporaryFolder;
import org.yaml.snakeyaml.Yaml;
+import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.assertFalse;
+import static org.junit.Assert.assertTrue;
+import static org.junit.Assert.fail;
+
/**
* Unit test for {@link YAMLConfiguration}
*/
public class TestYAMLConfiguration
{
+ @Rule
+ public TemporaryFolder temporaryFolder = new TemporaryFolder();
+
/** The files that we test with. */
private final String testYaml =
ConfigurationAssert.getTestFile("test.yaml").getAbsolutePath();
@@ -134,4 +145,40 @@
yamlConfiguration = new YAMLConfiguration(c);
assertEquals("bar", yamlConfiguration.getString("foo"));
}
+
+ @Test
+ public void testObjectCreationFromReader()
+ {
+ final File createdFile = new File(temporaryFolder.getRoot(), "data.txt");
+ final String yaml = "!!java.io.FileOutputStream [" + createdFile.getAbsolutePath() + "]";
+
+ try
+ {
+ yamlConfiguration.read(new StringReader(yaml));
+ fail("Loading configuration did not cause an exception!");
+ }
+ catch (ConfigurationException e)
+ {
+ //expected
+ }
+ assertFalse("Java object was created", createdFile.exists());
+ }
+
+ @Test
+ public void testObjectCreationFromStream()
+ {
+ final File createdFile = new File(temporaryFolder.getRoot(), "data.txt");
+ final String yaml = "!!java.io.FileOutputStream [" + createdFile.getAbsolutePath() + "]";
+
+ try
+ {
+ yamlConfiguration.read(new ByteArrayInputStream(yaml.getBytes(StandardCharsets.UTF_8)));
+ fail("Loading configuration did not cause an exception!");
+ }
+ catch (ConfigurationException e)
+ {
+ //expected
+ }
+ assertFalse("Java object was created", createdFile.exists());
+ }
}
