Implement JEXL parser settings

2 files changed, 134 insertions, 4 deletions

diff --git a/src/main/java/org/traccar/config/Keys.java b/src/main/java/org/traccar/config/Keys.java
index 093f4298c..49af7cfab 100644
--- a/src/main/java/org/traccar/config/Keys.java
+++ b/src/main/java/org/traccar/config/Keys.java
@@ -1299,6 +1299,101 @@ public final class Keys {
     public static final ConfigKey<Boolean> PROCESSING_COMPUTED_ATTRIBUTES_DEVICE_ATTRIBUTES = new BooleanConfigKey(
             "processing.computedAttributes.deviceAttributes",
             List.of(KeyType.CONFIG));
+    /**
+     * Enable annotation constructs processing.
+     * When disabled, parsing a script/expression using syntactic annotation constructs (@annotation) will throw a parsing exception.
+     */
+    public static final ConfigKey<Boolean> PROCESSING_COMPUTED_ATTRIBUTES_ANNOTATION = new BooleanConfigKey(
+            "processing.computedAttributes.parser.annotation",
+            List.of(KeyType.CONFIG));
+    /**
+     * Enable array references processing.
+     *  When disabled, parsing a script/expression using 'obj[ ref ]' where ref is not a string or integer literal will throw a parsing exception;
+     */
+    public static final ConfigKey<Boolean> PROCESSING_COMPUTED_ATTRIBUTES_ARRAY_REFERENCES = new BooleanConfigKey(
+            "processing.computedAttributes.parser.arrayReferences",
+            List.of(KeyType.CONFIG));
+    /**
+     * Enable lambda declaration.
+     * When disabled, parsing a script/expression using syntactic lambda constructs (->,function) will throw a parsing exception.
+     */
+    public static final ConfigKey<Boolean> PROCESSING_COMPUTED_ATTRIBUTES_LAMBDA = new BooleanConfigKey(
+            "processing.computedAttributes.parser.lambda",
+            List.of(KeyType.CONFIG));
+    /**
+     * Enable whether redefining local variables is an error.
+     * When disabled, parsing a script/expression using a local variable or parameter syntax will throw a parsing exception.
+     */
+    public static final ConfigKey<Boolean> PROCESSING_COMPUTED_ATTRIBUTES_LEXICAL = new BooleanConfigKey(
+            "processing.computedAttributes.parser.lexical",
+            List.of(KeyType.CONFIG));
+    /**
+     * Enable whether local variables shade global variables outside their scope.
+     */
+    public static final ConfigKey<Boolean> PROCESSING_COMPUTED_ATTRIBUTES_LEXICAL_SHADE = new BooleanConfigKey(
+            "processing.computedAttributes.parser.lexicalShade",
+            List.of(KeyType.CONFIG));
+    /**
+     * Enable local variables declaration.
+     */
+    public static final ConfigKey<Boolean> PROCESSING_COMPUTED_ATTRIBUTES_LOCAL_VARIABLES = new BooleanConfigKey(
+            "processing.computedAttributes.parser.localVariables",
+            List.of(KeyType.CONFIG));
+    /**
+     * Enable loops processing.
+     */
+    public static final ConfigKey<Boolean> PROCESSING_COMPUTED_ATTRIBUTES_LOOPS = new BooleanConfigKey(
+            "processing.computedAttributes.parser.loops",
+            List.of(KeyType.CONFIG));
+    /**
+     * Set whether object method calls are enabled.
+     * When disabled, parsing a script/expression using 'obj.method()' will throw a parsing exception;
+     */
+    public static final ConfigKey<Boolean> PROCESSING_COMPUTED_ATTRIBUTES_METHOD_CALLS = new BooleanConfigKey(
+            "processing.computedAttributes.parser.method_calls",
+            List.of(KeyType.CONFIG));
+    /**
+     * Enable new instances creation.
+     * When disabled, parsing a script/expression using 'new(...)' will throw a parsing exception; using a class as functor will fail.
+     */
+    public static final ConfigKey<Boolean> PROCESSING_COMPUTED_ATTRIBUTES_NEW_INSTANCE_CREATION = new BooleanConfigKey(
+            "processing.computedAttributes.parser.newInstanceCreation",
+            List.of(KeyType.CONFIG));
+    /**
+     * Enable pragma expressions processing.
+     * When disabled, parsing a script/expression using syntactic pragma constructs (#pragma) will throw a parsing exception.
+     */
+    public static final ConfigKey<Boolean> PROCESSING_COMPUTED_ATTRIBUTES_PRAGMA = new BooleanConfigKey(
+            "processing.computedAttributes.parser.pragma",
+            List.of(KeyType.CONFIG));
+    /**
+     * Enable scripts constructs processing.
+     * When disabled, parsing a script using syntactic script constructs (statements, ...) will throw a parsing exception.
+     * Dangerous, as can be used to escalate privileges on the Traccar server.
+     */
+    public static final ConfigKey<Boolean> PROCESSING_COMPUTED_ATTRIBUTES_SCRIPT_CONSTRUCTS = new BooleanConfigKey(
+            "processing.computedAttributes.parser.scriptConstructs",
+            List.of(KeyType.CONFIG));
+    /**
+     * Enable side effect expressions processing.
+     * When disabled, parsing a script/expression using syntactical constructs modifying variables or members will throw a parsing exception.
+     */
+    public static final ConfigKey<Boolean> PROCESSING_COMPUTED_ATTRIBUTES_SIDE_EFFECT = new BooleanConfigKey(
+            "processing.computedAttributes.parser.sideEffect",
+            List.of(KeyType.CONFIG));
+    /**
+     * Set whether side effect expressions on global variables (aka non-local) are enabled.
+     * When disabled, parsing a script/expression using syntactical constructs modifying variables including all potentially ant-ish variables will throw a parsing exception.
+     */
+    public static final ConfigKey<Boolean> PROCESSING_COMPUTED_ATTRIBUTES_SIDE_EFFECT_GLOBAL = new BooleanConfigKey(
+            "processing.computedAttributes.parser.sideEffectGlobal",
+            List.of(KeyType.CONFIG));
+    /**
+     * Enable array/map/set literal expressions processing.
+     */
+    public static final ConfigKey<Boolean> PROCESSING_COMPUTED_ATTRIBUTES_STRUCTURED_LITERAL = new BooleanConfigKey(
+            "processing.computedAttributes.parser.structuredLiteral",
+            List.of(KeyType.CONFIG));
 
     /**
      * Boolean flag to enable or disable reverse geocoder.
diff --git a/src/main/java/org/traccar/handler/ComputedAttributesHandler.java b/src/main/java/org/traccar/handler/ComputedAttributesHandler.java
index ca6c0fc74..c3f202fa2 100644
--- a/src/main/java/org/traccar/handler/ComputedAttributesHandler.java
+++ b/src/main/java/org/traccar/handler/ComputedAttributesHandler.java
@@ -26,10 +26,8 @@ import java.util.Map;
 import java.util.Set;
 
 import io.netty.channel.ChannelHandler;
-import org.apache.commons.jexl3.JexlBuilder;
-import org.apache.commons.jexl3.JexlEngine;
-import org.apache.commons.jexl3.JexlException;
-import org.apache.commons.jexl3.MapContext;
+import org.apache.commons.jexl3.*;
+import org.apache.commons.jexl3.introspection.JexlSandbox;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 import org.traccar.BaseDataHandler;
@@ -55,14 +53,51 @@ public class ComputedAttributesHandler extends BaseDataHandler {
 
     private final boolean includeDeviceAttributes;
 
+
     @Inject
     public ComputedAttributesHandler(Config config, CacheManager cacheManager) {
         this.cacheManager = cacheManager;
+        boolean enableJEXLAnnotation = config.getBoolean(Keys.PROCESSING_COMPUTED_ATTRIBUTES_ANNOTATION);
+        boolean enableJEXLArrayReferences = config.getBoolean(Keys.PROCESSING_COMPUTED_ATTRIBUTES_ARRAY_REFERENCES);
+        boolean enableJEXLLambdas = config.getBoolean(Keys.PROCESSING_COMPUTED_ATTRIBUTES_LAMBDA);
+        boolean enableJEXLLexical = config.getBoolean(Keys.PROCESSING_COMPUTED_ATTRIBUTES_LEXICAL);
+        boolean enableJEXLLexicalShade = config.getBoolean(Keys.PROCESSING_COMPUTED_ATTRIBUTES_LEXICAL_SHADE);
+        boolean enableJEXLLocalVariables = config.getBoolean(Keys.PROCESSING_COMPUTED_ATTRIBUTES_LOCAL_VARIABLES);
+        boolean enableJEXLLoops = config.getBoolean(Keys.PROCESSING_COMPUTED_ATTRIBUTES_LOOPS);
+        boolean enableJEXLMethodCalls = config.getBoolean(Keys.PROCESSING_COMPUTED_ATTRIBUTES_METHOD_CALLS);
+        boolean enableJEXLNewInstanceCreation = config.getBoolean(Keys.PROCESSING_COMPUTED_ATTRIBUTES_NEW_INSTANCE_CREATION);
+        boolean enableJEXLPragma = config.getBoolean(Keys.PROCESSING_COMPUTED_ATTRIBUTES_PRAGMA);
+        boolean enableJEXLScriptConstructs = config.getBoolean(Keys.PROCESSING_COMPUTED_ATTRIBUTES_SCRIPT_CONSTRUCTS);
+        boolean enableJEXLSideEffect = config.getBoolean(Keys.PROCESSING_COMPUTED_ATTRIBUTES_SIDE_EFFECT);
+        boolean enableJEXLSideEffectGlobal = config.getBoolean(Keys.PROCESSING_COMPUTED_ATTRIBUTES_SIDE_EFFECT_GLOBAL);
+        boolean enableJEXLStructuredLiteral = config.getBoolean(Keys.PROCESSING_COMPUTED_ATTRIBUTES_STRUCTURED_LITERAL);
+        JexlSandbox sandbox = new JexlSandbox(false);
+        sandbox.allow("com.safe.Functions");
+        boolean enableJEXLRegister = true;
+        JexlFeatures features = new JexlFeatures()
+                .annotation(enableJEXLAnnotation)
+                .arrayReferenceExpr(enableJEXLArrayReferences)
+                .lambda(enableJEXLLambdas)
+                .lexical(enableJEXLLexical)
+                .lexicalShade(enableJEXLLexicalShade)
+                .localVar(enableJEXLLocalVariables)
+                .loops(enableJEXLLoops)
+                .methodCall(enableJEXLMethodCalls)
+                .newInstance(enableJEXLNewInstanceCreation)
+                .pragma(enableJEXLPragma)
+                .register(enableJEXLRegister)
+                .script(enableJEXLScriptConstructs)
+                .sideEffect(enableJEXLSideEffect)
+                .sideEffectGlobal(enableJEXLSideEffectGlobal)
+                .structuredLiteral(enableJEXLStructuredLiteral);
         engine = new JexlBuilder()
                 .strict(true)
                 .namespaces(Collections.singletonMap("math", Math.class))
+                .sandbox(sandbox)
+                .features(features)
                 .create();
         includeDeviceAttributes = config.getBoolean(Keys.PROCESSING_COMPUTED_ATTRIBUTES_DEVICE_ATTRIBUTES);
+
     }
 
     private MapContext prepareContext(Position position) {