DRILL-8289: Add Threat Hunting Functions (#2634)
diff --git a/contrib/udfs/README.md b/contrib/udfs/README.md
index 6f6799d..f8e47b9 100644
--- a/contrib/udfs/README.md
+++ b/contrib/udfs/README.md
@@ -415,3 +415,14 @@
```
The function returns an empty map if the row is `null`.
+
+# Threat Hunting Functions
+These functions are useful for doing threat hunting with Apache Drill. These were inspired by huntlib.[1]
+
+The functions are:
+* `punctuation_pattern(<string>)`: Extracts the pattern of punctuation in text.
+* `entropy(<string>)`: This function calculates the Shannon Entropy of a given string of text.
+* `entropyPerByte(<string>)`: This function calculates the Shannon Entropy of a given string of text, normed for the string length.
+
+[1]: https://github.com/target/huntlib
+
diff --git a/contrib/udfs/src/main/java/org/apache/drill/exec/udfs/ThreatHuntingFunctions.java b/contrib/udfs/src/main/java/org/apache/drill/exec/udfs/ThreatHuntingFunctions.java
new file mode 100644
index 0000000..782ea53
--- /dev/null
+++ b/contrib/udfs/src/main/java/org/apache/drill/exec/udfs/ThreatHuntingFunctions.java
@@ -0,0 +1,179 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements. See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership. The ASF licenses this file
+ * to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance
+ * with the License. You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package org.apache.drill.exec.udfs;
+
+import io.netty.buffer.DrillBuf;
+import org.apache.drill.exec.expr.DrillSimpleFunc;
+import org.apache.drill.exec.expr.annotations.FunctionTemplate;
+import org.apache.drill.exec.expr.annotations.Output;
+import org.apache.drill.exec.expr.annotations.Param;
+import org.apache.drill.exec.expr.holders.Float8Holder;
+import org.apache.drill.exec.expr.holders.VarCharHolder;
+
+import javax.inject.Inject;
+
+public class ThreatHuntingFunctions {
+ /**
+ * Punctuation pattern is useful for comparing log entries. It extracts all the punctuation and returns
+ * that pattern. Spaces are replaced with an underscore.
+ * <p>
+ * Usage: SELECT punctuation_pattern( string ) FROM...
+ */
+ @FunctionTemplate(names = {"punctuation_pattern", "punctuationPattern"},
+ scope = FunctionTemplate.FunctionScope.SIMPLE,
+ nulls = FunctionTemplate.NullHandling.NULL_IF_NULL)
+ public static class PunctuationPatternFunction implements DrillSimpleFunc {
+
+ @Param
+ VarCharHolder rawInput;
+
+ @Output
+ VarCharHolder out;
+
+ @Inject
+ DrillBuf buffer;
+
+ @Override
+ public void setup() {
+ }
+
+ @Override
+ public void eval() {
+
+ String input = org.apache.drill.exec.expr.fn.impl.StringFunctionHelpers.toStringFromUTF8(rawInput.start, rawInput.end, rawInput.buffer);
+
+ String punctuationPattern = input.replaceAll("[a-zA-Z0-9]", "");
+ punctuationPattern = punctuationPattern.replaceAll(" ", "_");
+
+ out.buffer = buffer;
+ out.start = 0;
+ out.end = punctuationPattern.getBytes(java.nio.charset.StandardCharsets.UTF_8).length;
+ buffer.setBytes(0, punctuationPattern.getBytes());
+ }
+ }
+
+ /**
+ * This function calculates the Shannon Entropy of a given string of text.
+ * See: https://en.wikipedia.org/wiki/Entropy_(information_theory) for full definition.
+ * <p>
+ * Usage:
+ * SELECT entropy(<varchar>) AS entropy FROM...
+ *
+ * Returns a double
+ */
+ @FunctionTemplate(name = "entropy",
+ scope = FunctionTemplate.FunctionScope.SIMPLE,
+ nulls = FunctionTemplate.NullHandling.NULL_IF_NULL)
+ public static class StringEntropyFunction implements DrillSimpleFunc {
+
+ @Param
+ VarCharHolder rawInput1;
+
+ @Output
+ Float8Holder out;
+
+ @Override
+ public void setup() {}
+
+ @Override
+ public void eval() {
+
+ String input = org.apache.drill.exec.expr.fn.impl.StringFunctionHelpers.toStringFromUTF8(rawInput1.start, rawInput1.end, rawInput1.buffer);
+ java.util.Set<Character> chars = new java.util.HashSet();
+
+ for (char ch : input.toCharArray()) {
+ chars.add(ch);
+ }
+
+ java.util.Map<Character, Double> probabilities = new java.util.HashMap();
+ int length = input.length();
+
+ // Get the probabilities
+ for (Character character : chars) {
+ double charCount = org.apache.commons.lang3.StringUtils.countMatches(input, character);
+ double probability = charCount / length;
+ probabilities.put(character, probability);
+ }
+
+ // Now get the entropy
+ double entropy = 0.0;
+ for (Double probability : probabilities.values()) {
+ entropy += (probability * java.lang.Math.log(probability) / java.lang.Math.log(2.0));
+ }
+ out.value = Math.abs(entropy);
+ }
+ }
+
+ /**
+ * This function calculates the Shannon Entropy of a given string of text, normed for the string length.
+ * See: https://en.wikipedia.org/wiki/Entropy_(information_theory) for full definition.
+ * <p>
+ * Usage:
+ * SELECT entropy_per_byte(<varchar>) AS entropy FROM...
+ *
+ * Returns a double
+ */
+ @FunctionTemplate(names = {"entropy_per_byte", "entropyPerByte"},
+ scope = FunctionTemplate.FunctionScope.SIMPLE,
+ nulls = FunctionTemplate.NullHandling.NULL_IF_NULL)
+
+ public static class NormedStringEntropyFunction implements DrillSimpleFunc {
+
+ @Param
+ VarCharHolder rawInput;
+
+ @Output
+ Float8Holder out;
+
+ @Override
+ public void setup() {}
+
+ @Override
+ public void eval() {
+
+ String input = org.apache.drill.exec.expr.fn.impl.StringFunctionHelpers.getStringFromVarCharHolder(rawInput);
+ java.util.Set<Character> chars = new java.util.HashSet();
+
+ for (char ch : input.toCharArray()) {
+ chars.add(ch);
+ }
+
+ java.util.Map<Character, Double> probabilities = new java.util.HashMap();
+ int length = input.length();
+
+ // Get the probabilities
+ for (Character character : chars) {
+ double charCount = org.apache.commons.lang3.StringUtils.countMatches(input, character);
+ double probability = charCount / length;
+ probabilities.put(character, probability);
+ }
+
+ // Now get the entropy
+ double entropy = 0.0;
+ for (Double probability : probabilities.values()) {
+ entropy += (probability * java.lang.Math.log(probability) / java.lang.Math.log(2.0));
+ }
+
+ if (input.length() == 0) {
+ out.value = 0.0;
+ } else {
+ out.value = (Math.abs(entropy) / input.length());
+ }
+ }
+ }
+}
diff --git a/contrib/udfs/src/test/java/org/apache/drill/exec/udfs/TestThreatHuntingFunctions.java b/contrib/udfs/src/test/java/org/apache/drill/exec/udfs/TestThreatHuntingFunctions.java
new file mode 100644
index 0000000..9e8f3d3
--- /dev/null
+++ b/contrib/udfs/src/test/java/org/apache/drill/exec/udfs/TestThreatHuntingFunctions.java
@@ -0,0 +1,107 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements. See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership. The ASF licenses this file
+ * to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance
+ * with the License. You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.apache.drill.exec.udfs;
+
+import org.apache.drill.categories.SqlFunctionTest;
+import org.apache.drill.categories.UnlikelyTest;
+import org.apache.drill.test.ClusterFixture;
+import org.apache.drill.test.ClusterFixtureBuilder;
+import org.apache.drill.test.ClusterTest;
+import org.junit.BeforeClass;
+import org.junit.Test;
+import org.junit.experimental.categories.Category;
+
+@Category({UnlikelyTest.class, SqlFunctionTest.class})
+public class TestThreatHuntingFunctions extends ClusterTest {
+
+ @BeforeClass
+ public static void setup() throws Exception {
+ ClusterFixtureBuilder builder = ClusterFixture.builder(dirTestWatcher);
+ startCluster(builder);
+ }
+
+ @Test
+ public void testPunctuationPattern() throws Exception {
+ String query = "SELECT punctuation_pattern('192.168.1.1 - - [10/Oct/2020:12:32:27 +0000] \"GET /some/web/app?param=test¶m2=another_test\" 200 9987') AS pp FROM (VALUES" +
+ "(1))";
+ testBuilder()
+ .sqlQuery(query)
+ .ordered()
+ .baselineColumns("pp")
+ .baselineValues("..._-_-_[//:::_+]_\"_///?=&=_\"__")
+ .go();
+ }
+
+ @Test
+ public void testEmptyPunctuationPattern() throws Exception {
+ String query = "SELECT punctuation_pattern('') AS pp FROM (VALUES(1))";
+ testBuilder()
+ .sqlQuery(query)
+ .ordered()
+ .baselineColumns("pp")
+ .baselineValues("")
+ .go();
+ }
+
+ @Test
+ public void testEntropyFunction() throws Exception {
+ String query = "SELECT entropy('asdkjflkdsjlefjdc') AS entropy FROM (VALUES(1))";
+ testBuilder()
+ .sqlQuery(query)
+ .ordered()
+ .baselineColumns("entropy")
+ .baselineValues(3.057476076289932)
+ .go();
+ }
+
+ @Test
+ public void testEntropyFunctionWithEmptyString() throws Exception {
+ String query = "SELECT entropy('') AS entropy FROM (VALUES(1))";
+ testBuilder()
+ .sqlQuery(query)
+ .ordered()
+ .baselineColumns("entropy")
+ .baselineValues(0.0)
+ .go();
+ }
+
+ @Test
+ public void testNormedEntropyFunction() throws Exception {
+ String query = "SELECT entropy_per_byte('asdkjflkdsjlefjdc') AS entropy FROM (VALUES(1))";
+ testBuilder()
+ .sqlQuery(query)
+ .ordered()
+ .baselineColumns("entropy")
+ .baselineValues(0.17985153389940778)
+ .go();
+ }
+
+ @Test
+ public void testNormedEntropyFunctionWithEmptyString() throws Exception {
+ String query = "SELECT entropy_per_byte('') AS entropy FROM (VALUES(1))";
+ testBuilder()
+ .sqlQuery(query)
+ .ordered()
+ .baselineColumns("entropy")
+ .baselineValues(0.0)
+ .go();
+ }
+
+}
+
