Merge pull request #12882 from vespa-engine/hakonhall/validate-deserialization-of-flag-data

Validate deserialization of flag data

5 files changed, 66 insertions, 6 deletions

diff --git a/vespajlib/src/main/java/com/yahoo/slime/JsonDecoder.java b/vespajlib/src/main/java/com/yahoo/slime/JsonDecoder.java
index f199fefd185..f677ae23a45 100644
--- a/vespajlib/src/main/java/com/yahoo/slime/JsonDecoder.java
+++ b/vespajlib/src/main/java/com/yahoo/slime/JsonDecoder.java
@@ -3,10 +3,8 @@ package com.yahoo.slime;
 
 import com.yahoo.text.Text;
 import com.yahoo.text.Utf8;
-import org.w3c.dom.CharacterData;
 
 import java.io.ByteArrayOutputStream;
-import java.nio.charset.StandardCharsets;
 
 /**
  * A port of the C++ json decoder intended to be fast.
@@ -47,6 +45,17 @@ public class JsonDecoder {
         return slime;
     }
 
+    /** Decode bytes as a UTF-8 JSON into Slime, or throw {@link JsonParseException} on invalid JSON. */
+    public Slime decodeOrThrow(Slime slime, byte[] bytes) {
+        in = new BufferedInput(bytes);
+        next();
+        decodeValue(slimeInserter.adjust(slime));
+        if (in.failed()) {
+            throw new JsonParseException(in);
+        }
+        return slime;
+    }
+
     private void decodeValue(Inserter inserter) {
         skipWhiteSpace();
         switch (c) {
diff --git a/vespajlib/src/main/java/com/yahoo/slime/JsonParseException.java b/vespajlib/src/main/java/com/yahoo/slime/JsonParseException.java
new file mode 100644
index 00000000000..6c42f7d38c1
--- /dev/null
+++ b/vespajlib/src/main/java/com/yahoo/slime/JsonParseException.java
@@ -0,0 +1,23 @@
+// Copyright Verizon Media. Licensed under the terms of the Apache 2.0 license. See LICENSE in the project root.
+package com.yahoo.slime;
+
+/**
+ * @author hakonhall
+ */
+public class JsonParseException extends RuntimeException {
+
+    private static final long serialVersionUID = 1586949558L;
+
+    private final BufferedInput input;
+
+    JsonParseException(BufferedInput input) {
+        super(input.getErrorMessage());
+        this.input = input;
+    }
+
+    public byte[] getOffendingBytes() {
+        // potentially expensive array copy
+        return input.getOffending();
+    }
+
+}
diff --git a/vespajlib/src/main/java/com/yahoo/slime/Slime.java b/vespajlib/src/main/java/com/yahoo/slime/Slime.java
index 8357e3035c0..83934e0c206 100644
--- a/vespajlib/src/main/java/com/yahoo/slime/Slime.java
+++ b/vespajlib/src/main/java/com/yahoo/slime/Slime.java
@@ -159,11 +159,10 @@ public final class Slime {
     }
 
     /**
-     * Tests whether this is equal to Inspector.
+     * Tests whether the two Inspectors are equal.
      *
-     * Since equality of two Inspectors is subtle, {@link Object#equals(Object)} is not used.
+     * <p>Since equality of two Inspectors is subtle, {@link Object#equals(Object)} is not used.</p>
      *
-     * @param that inspector.
      * @return true if they are equal.
      */
     public boolean equalTo(Slime that) {
diff --git a/vespajlib/src/main/java/com/yahoo/slime/SlimeUtils.java b/vespajlib/src/main/java/com/yahoo/slime/SlimeUtils.java
index 4d0b3a8ff2e..2ed7331a60c 100644
--- a/vespajlib/src/main/java/com/yahoo/slime/SlimeUtils.java
+++ b/vespajlib/src/main/java/com/yahoo/slime/SlimeUtils.java
@@ -104,6 +104,17 @@ public class SlimeUtils {
         return jsonToSlime(json.getBytes(StandardCharsets.UTF_8));
     }
 
+    /** Throws {@link JsonParseException} on invalid JSON. */
+    public static Slime jsonToSlimeOrThrow(String json) {
+        return jsonToSlimeOrThrow(json.getBytes(StandardCharsets.UTF_8));
+    }
+
+    public static Slime jsonToSlimeOrThrow(byte[] json) {
+        Slime slime = new Slime();
+        new JsonDecoder().decodeOrThrow(slime, json);
+        return slime;
+    }
+
     public static Optional<String> optionalString(Inspector inspector) {
         return Optional.of(inspector.asString()).filter(s -> !s.isEmpty());
     }
diff --git a/vespajlib/src/main/java/com/yahoo/text/JSON.java b/vespajlib/src/main/java/com/yahoo/text/JSON.java
index cfff16c9aba..11e5be9328e 100644
--- a/vespajlib/src/main/java/com/yahoo/text/JSON.java
+++ b/vespajlib/src/main/java/com/yahoo/text/JSON.java
@@ -1,10 +1,13 @@
 // Copyright 2017 Yahoo Holdings. Licensed under the terms of the Apache 2.0 license. See LICENSE in the project root.
 package com.yahoo.text;
 
+import com.yahoo.slime.Slime;
+import com.yahoo.slime.SlimeUtils;
+
 import java.util.Map;
 
 /**
- * Static methods for working with the map textual format which is parsed by {@link MapParser}
+ * Static methods for working with JSON.
  *
  * @author bratseth
  */
@@ -56,4 +59,19 @@ public final class JSON {
         return b != null ? b.toString() : s;
     }
 
+    /**
+     * Test whether two JSON strings are equal, e.g. the order of fields in an object is irrelevant.
+     *
+     * <p>When comparing two numbers of the two JSON strings, the result is only guaranteed to be
+     * correct if (a) both are integers (without fraction and exponent) and each fits in a long, or
+     * (b) both are non-integers, are syntactically identical, and fits in a double.</p>
+     *
+     * @throws RuntimeException on invalid JSON
+     */
+    public static boolean equals(String left, String right) {
+        Slime leftSlime = SlimeUtils.jsonToSlimeOrThrow(left);
+        Slime rightSlime = SlimeUtils.jsonToSlimeOrThrow(right);
+        return leftSlime.equalTo(rightSlime);
+    }
+
 }