commit fb7fe28f7f7e948d6ce4c8e9b1ba9c3999c819ac
author Greg Kerr <kerrnel@chromium.org> Thu Jul 21 22:17:00 2016
committer chrome-bot <chrome-bot@chromium.org> Tue Jul 26 02:12:01 2016
tree 385f333de9c877b006f09a28a86992d56ebc65e1
parent 87bf7257b9f003a166b2853f83fcbe9f30dc8c1e

Add code to query the version of a component.

This code allows consumers to query the version of a component by name.

BUG=chromium:630421
TEST=emerge imageloader, and run with test components on device.

Change-Id: I25fb85f4a3ae6eacacb86407d6b6fcf08e3f94a9
Reviewed-on: https://chromium-review.googlesource.com/362990
Commit-Ready: Greg Kerr <kerrnel@chromium.org>
Tested-by: Greg Kerr <kerrnel@chromium.org>
Reviewed-by: Ricky Zhou <rickyz@chromium.org>

imageloader.cc

diff --git a/imageloader.cc b/imageloader.cc
index c96cf8a..1e70ae8 100644
--- a/imageloader.cc
+++ b/imageloader.cc
@@ -520,13 +520,45 @@
 
 std::string ImageLoader::GetComponentVersion(const std::string& name,
                                              ::DBus::Error& err) {
-  if (reg.find(name) != reg.end()) {
-    LOG(INFO) << "Found entry (" << name << ", " << reg[name].first << ", "
-              << reg[name].second.value() << ")";
-    return reg[name].first;
+  base::FilePath component_path = base::FilePath(kComponentsPath).Append(name);
+  if (!base::PathExists(component_path)) {
+    LOG(ERROR) << "Component does not exist.";
+    return kBadResult;
   }
-  LOG(ERROR) << "Entry not found : " << name;
-  return kBadResult;
+
+  std::string current_version_hint;
+  base::FilePath version_hint_path = component_path.Append(name);
+  if (!base::ReadFileToStringWithMaxSize(
+          version_hint_path, &current_version_hint, kMaximumFilesize)) {
+    return kBadResult;
+  }
+
+  // The version can be security sensitive (i.e. which flash player does Chrome
+  // load), so check the signed manfiest as the final answer.
+  std::string manifest_contents;
+  if (!base::ReadFileToStringWithMaxSize(component_path.Append(kManifestName),
+                                         &manifest_contents,
+                                         kMaximumFilesize)) {
+    return kBadResult;
+  }
+
+  // Read in the manifest signature.
+  std::string manifest_sig;
+  base::FilePath manifest_sig_path =
+      component_path.Append(kManifestSignatureName);
+  if (!base::ReadFileToStringWithMaxSize(manifest_sig_path, &manifest_sig,
+                                         kMaximumFilesize)) {
+    return kBadResult;
+  }
+
+  Manifest manifest;
+  if (!VerifyAndParseManifest(manifest_contents, manifest_sig, &manifest)) {
+    LOG(ERROR) << "Could not verify and parse the manifest.";
+    return kBadResult;
+  }
+
+  return manifest.version == current_version_hint ? manifest.version
+                                                  : kBadResult;
 }
 
 std::string ImageLoader::LoadComponent(const std::string& name,