Add a method to classify what permission class an extension is in, with unit

tests.

BUG=12140

Review URL: http://codereview.chromium.org/164335

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@23229 0039d316-1c4b-4281-b951-d872f2087c98

3 files changed, 110 insertions, 0 deletions

diff --git a/chrome/common/extensions/extension.cc b/chrome/common/extensions/extension.cc
index 637be5e..0ed6bf5 100644
--- a/chrome/common/extensions/extension.cc
+++ b/chrome/common/extensions/extension.cc
@@ -952,6 +952,25 @@ std::set<FilePath> Extension::GetBrowserImages() {
   return image_paths;
 }
 
+Extension::PermissionClass Extension::GetPermissionClass() {
+  // Native code can do anything. Highest class.
+  if (!plugins_.empty())
+    return PERMISSION_CLASS_FULL;
+
+  // Access to other sites means the extension can steal cookies (login data)
+  // from those sites.
+  // TODO(mpcomplete): should we only classify for host access outside the
+  // extension's origin? how?
+  if (!host_permissions_.empty() || !content_scripts_.empty())
+    return PERMISSION_CLASS_HIGH;
+
+  // Extension can access history data, bookmarks, other personal info.
+  if (!api_permissions_.empty())
+    return PERMISSION_CLASS_MEDIUM;
+
+  return PERMISSION_CLASS_LOW;
+}
+
 bool Extension::GetBackgroundPageReady() {
   return background_page_ready_ || background_url().is_empty();
 }
diff --git a/chrome/common/extensions/extension.h b/chrome/common/extensions/extension.h
index 7969e96..1452014 100644
--- a/chrome/common/extensions/extension.h
+++ b/chrome/common/extensions/extension.h
@@ -62,6 +62,15 @@ class Extension {
   static const char* kPermissionNames[];
   static const size_t kNumPermissions;
 
+  // A classification of how dangerous an extension can be, based on what it has
+  // access to.
+  enum PermissionClass {
+    PERMISSION_CLASS_LOW = 0,  // green
+    PERMISSION_CLASS_MEDIUM,  // yellow
+    PERMISSION_CLASS_HIGH,  // orange
+    PERMISSION_CLASS_FULL,  // red
+  };
+
   // An NPAPI plugin included in the extension.
   struct PluginInfo {
     FilePath path;  // Path to the plugin.
@@ -205,6 +214,8 @@ class Extension {
   // the browser might load (like themes and page action icons).
   std::set<FilePath> GetBrowserImages();
 
+  PermissionClass GetPermissionClass();
+
 
   // Runtime data:
   // Put dynamic data about the state of a running extension below.
diff --git a/chrome/common/extensions/extension_unittest.cc b/chrome/common/extensions/extension_unittest.cc
index 6eba35a..a0eed4e 100644
--- a/chrome/common/extensions/extension_unittest.cc
+++ b/chrome/common/extensions/extension_unittest.cc
@@ -21,6 +21,14 @@ namespace errors = extension_manifest_errors;
 class ExtensionTest : public testing::Test {
 };
 
+static Value* ValueFromJSON(const std::string& json_string) {
+  std::string error;
+  JSONStringValueSerializer content_scripts(json_string);
+  Value* result = content_scripts.Deserialize(&error);
+  DCHECK(result) << error;
+  return result;
+}
+
 TEST(ExtensionTest, InitFromValueInvalid) {
 #if defined(OS_WIN)
   FilePath path(FILE_PATH_LITERAL("c:\\foo"));
@@ -455,3 +463,75 @@ TEST(ExtensionTest, MimeTypeSniffing) {
               GURL("http://www.example.com/foo.crx"), "", &result));
   EXPECT_EQ("application/octet-stream", result);
 }
+
+TEST(ExtensionTest, PermissionClass) {
+#if defined(OS_WIN)
+  FilePath path(FILE_PATH_LITERAL("C:\\foo"));
+#elif defined(OS_POSIX)
+  FilePath path(FILE_PATH_LITERAL("/foo"));
+#endif
+  Extension::ResetGeneratedIdCounter();
+
+  Extension extension(path);
+  std::string error;
+  DictionaryValue bare_manifest;
+  scoped_ptr<DictionaryValue> manifest;
+
+  // Start with a minimalist extension.
+  bare_manifest.SetString(keys::kVersion, "1.0.0.0");
+  bare_manifest.SetString(keys::kName, "my extension");
+  EXPECT_TRUE(extension.InitFromValue(bare_manifest, false, &error));
+  EXPECT_EQ(Extension::PERMISSION_CLASS_LOW, extension.GetPermissionClass());
+
+  // Toolstrips don't affect the permission class.
+  manifest.reset(static_cast<DictionaryValue*>(bare_manifest.DeepCopy()));
+  manifest->Set(keys::kToolstrips, ValueFromJSON(
+      "[\"toolstrip.html\", \"toolstrip2.html\"]"));
+  EXPECT_TRUE(extension.InitFromValue(*manifest, false, &error));
+  EXPECT_EQ(Extension::PERMISSION_CLASS_LOW, extension.GetPermissionClass());
+
+  // Requesting API permissions bumps you to medium.
+  manifest.reset(static_cast<DictionaryValue*>(bare_manifest.DeepCopy()));
+  manifest->Set(keys::kPermissions, ValueFromJSON(
+      "[\"tabs\", \"bookmarks\"]"));
+  EXPECT_TRUE(extension.InitFromValue(*manifest, false, &error));
+  EXPECT_EQ(Extension::PERMISSION_CLASS_MEDIUM, extension.GetPermissionClass());
+
+  // Adding a content script bumps you to high.
+  manifest.reset(static_cast<DictionaryValue*>(bare_manifest.DeepCopy()));
+  manifest->Set(keys::kContentScripts, ValueFromJSON(
+      "[{"
+      "  \"matches\": [\"http://*.google.com/*\"],"
+      "  \"js\": [\"script.js\"]"
+      "}]"));
+  EXPECT_TRUE(extension.InitFromValue(*manifest, false, &error));
+  EXPECT_EQ(Extension::PERMISSION_CLASS_HIGH, extension.GetPermissionClass());
+
+  // ... or asking for a host permission.
+  manifest.reset(static_cast<DictionaryValue*>(bare_manifest.DeepCopy()));
+  manifest->Set(keys::kPermissions, ValueFromJSON(
+      "[\"tabs\", \"http://google.com/*\"]"));
+  EXPECT_TRUE(extension.InitFromValue(*manifest, false, &error));
+  EXPECT_EQ(Extension::PERMISSION_CLASS_HIGH, extension.GetPermissionClass());
+
+  // Using native code (NPAPI) is automatically the max class.
+  manifest.reset(static_cast<DictionaryValue*>(bare_manifest.DeepCopy()));
+  manifest->Set(keys::kPlugins, ValueFromJSON(
+      "[{\"path\": \"harddrive_exploder.dll\"}]"));
+  EXPECT_TRUE(extension.InitFromValue(*manifest, false, &error));
+  EXPECT_EQ(Extension::PERMISSION_CLASS_FULL, extension.GetPermissionClass());
+
+  // Using everything at once should obviously be the max class as well.
+  manifest.reset(static_cast<DictionaryValue*>(bare_manifest.DeepCopy()));
+  manifest->Set(keys::kPlugins, ValueFromJSON(
+      "[{\"path\": \"harddrive_exploder.dll\"}]"));
+  manifest->Set(keys::kPermissions, ValueFromJSON(
+      "[\"tabs\", \"http://google.com/*\"]"));
+  manifest->Set(keys::kContentScripts, ValueFromJSON(
+      "[{"
+      "  \"matches\": [\"http://*.google.com/*\"],"
+      "  \"js\": [\"script.js\"]"
+      "}]"));
+  EXPECT_TRUE(extension.InitFromValue(*manifest, false, &error));
+  EXPECT_EQ(Extension::PERMISSION_CLASS_FULL, extension.GetPermissionClass());
+}