From b563f573de781219d7d3e5a7b591129be20b5ced Mon Sep 17 00:00:00 2001
From: Harald Kuhr <harald.kuhr@gmail.com>
Date: Sat, 21 Nov 2020 20:49:21 +0100
Subject: [PATCH] Better input validation.

---
 .../imageio/plugins/iff/IFFImageMetadata.java | 31 ++++++++++++++-----
 1 file changed, 24 insertions(+), 7 deletions(-)

diff --git a/imageio/imageio-iff/src/main/java/com/twelvemonkeys/imageio/plugins/iff/IFFImageMetadata.java b/imageio/imageio-iff/src/main/java/com/twelvemonkeys/imageio/plugins/iff/IFFImageMetadata.java
index 846c0f15..7ded0a4c 100644
--- a/imageio/imageio-iff/src/main/java/com/twelvemonkeys/imageio/plugins/iff/IFFImageMetadata.java
+++ b/imageio/imageio-iff/src/main/java/com/twelvemonkeys/imageio/plugins/iff/IFFImageMetadata.java
@@ -1,13 +1,16 @@
 package com.twelvemonkeys.imageio.plugins.iff;
 
+import com.twelvemonkeys.imageio.AbstractMetadata;
+
+import javax.imageio.metadata.IIOMetadataNode;
 import java.awt.*;
 import java.awt.image.IndexColorModel;
 import java.nio.charset.StandardCharsets;
 import java.util.List;
 
-import javax.imageio.metadata.IIOMetadataNode;
-
-import com.twelvemonkeys.imageio.AbstractMetadata;
+import static com.twelvemonkeys.imageio.plugins.iff.IFF.*;
+import static com.twelvemonkeys.lang.Validate.isTrue;
+import static com.twelvemonkeys.lang.Validate.notNull;
 
 final class IFFImageMetadata extends AbstractMetadata {
     private final int formType;
@@ -17,13 +20,27 @@ final class IFFImageMetadata extends AbstractMetadata {
     private final List<GenericChunk> meta;
 
     IFFImageMetadata(int formType, BMHDChunk header, IndexColorModel colorMap, CAMGChunk viewPort, List<GenericChunk> meta) {
-        this.formType = formType;
-        this.header = header;
+        this.formType = isTrue(validFormType(formType), formType, "Unknown IFF Form type: %s");
+        this.header = notNull(header, "header");
         this.colorMap = colorMap;
         this.viewPort = viewPort;
         this.meta = meta;
     }
 
+    private boolean validFormType(int formType) {
+        switch (formType) {
+            case TYPE_ACBM:
+            case TYPE_DEEP:
+            case TYPE_ILBM:
+            case TYPE_PBM:
+            case TYPE_RGB8:
+            case TYPE_RGBN:
+                return true;
+            default:
+                return false;
+        }
+    }
+
     @Override
     protected IIOMetadataNode getStandardChromaNode() {
         IIOMetadataNode chroma = new IIOMetadataNode("Chroma");
@@ -128,10 +145,10 @@ final class IFFImageMetadata extends AbstractMetadata {
         // PlanarConfiguration
         IIOMetadataNode planarConfiguration = new IIOMetadataNode("PlanarConfiguration");
         switch (formType) {
-            case IFF.TYPE_PBM:
+            case TYPE_PBM:
                 planarConfiguration.setAttribute("value", "PixelInterleaved");
                 break;
-            case IFF.TYPE_ILBM:
+            case TYPE_ILBM:
                 planarConfiguration.setAttribute("value", "PlaneInterleaved");
                 break;
             default: