From 057daed8cdadd1cfdb5080e8418797542eb62978 Mon Sep 17 00:00:00 2001
From: Christian Stein <sormuras@gmail.com>
Date: Tue, 20 Jan 2026 13:36:06 +0100
Subject: [PATCH] 8375433: jar should validate module names

---
 .../classes/sun/tools/jar/Validator.java      | 24 ++++++++++++++++++-
 .../sun/tools/jar/resources/jar.properties    |  4 ++++
 2 files changed, 27 insertions(+), 1 deletion(-)

diff --git a/src/jdk.jartool/share/classes/sun/tools/jar/Validator.java b/src/jdk.jartool/share/classes/sun/tools/jar/Validator.java
index be694eeb1bc..9b9e6a8892b 100644
--- a/src/jdk.jartool/share/classes/sun/tools/jar/Validator.java
+++ b/src/jdk.jartool/share/classes/sun/tools/jar/Validator.java
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2017, 2025, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2017, 2026, Oracle and/or its affiliates. All rights reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
@@ -47,6 +47,8 @@ import java.util.function.Function;
 import java.util.function.IntSupplier;
 import java.util.regex.Pattern;
 import java.util.stream.Collectors;
+import java.util.jar.Attributes;
+import java.util.jar.Manifest;
 import java.util.zip.ZipEntry;
 import java.util.zip.ZipFile;
 import java.util.zip.ZipInputStream;
@@ -272,6 +274,26 @@ final class Validator {
                         errorAndInvalid(formatMsg("error.validator.metainf.wrong.position", firstName));
                     }
                 }
+                // Check for a valid and consistent automatic module name
+                try (InputStream jis = zf.getInputStream(zf.getEntry(entryName))) {
+                    Manifest manifest = new Manifest(jis);
+                    Attributes global = manifest.getMainAttributes();
+                    String name = global.getValue("Automatic-Module-Name");
+                    if (name != null) {
+                        try {
+                            ModuleDescriptor.newAutomaticModule(name);
+                        } catch (IllegalArgumentException e) {
+                            errorAndInvalid(formatMsg("error.validator.manifest.invalid.automatic.module.name", name));
+                        }
+                        if (md != null) {
+                            if (!name.equals(md.name())) {
+                                errorAndInvalid(formatMsg("error.validator.manifest.inconsistent.automatic.module.name", name, md.name()));
+                            }
+                        }
+                    }
+                } catch (IOException e) {
+                    errorAndInvalid(e.getMessage());
+                }
             }
         }
 
diff --git a/src/jdk.jartool/share/classes/sun/tools/jar/resources/jar.properties b/src/jdk.jartool/share/classes/sun/tools/jar/resources/jar.properties
index c80377e20c1..62adaa3351e 100644
--- a/src/jdk.jartool/share/classes/sun/tools/jar/resources/jar.properties
+++ b/src/jdk.jartool/share/classes/sun/tools/jar/resources/jar.properties
@@ -138,6 +138,10 @@ error.validator.metainf.wrong.position=\
         expected entry META-INF/ to be at position 0, but found: {0}
 error.validator.manifest.wrong.position=\
         expected entry META-INF/MANIFEST.MF to be at position 0 or 1, but found it at position: {0}
+error.validator.manifest.invalid.automatic.module.name=\
+        invalid module name of Automatic-Module-Name entry in manifest: {0}
+error.validator.manifest.inconsistent.automatic.module.name=\
+        expected module name is: {1} - but found Automatic-Module-Name entry in manifest: {0}
 warn.validator.identical.entry=\
         Warning: entry {0} contains a class that\n\
         is identical to an entry already in the jar