Validate hash_sha256 checksum on .crx update.

extensions/browser/sandboxed_unpacker.h

Index: extensions/browser/sandboxed_unpacker.h
diff --git a/extensions/browser/sandboxed_unpacker.h b/extensions/browser/sandboxed_unpacker.h
index 60a5bbdd4aa0b517857e283c22c11b4bcc92bb2a..315f444959f992484b5c4107a06fdb0a422c96c0 100644
--- a/extensions/browser/sandboxed_unpacker.h
+++ b/extensions/browser/sandboxed_unpacker.h
@@ -12,6 +12,8 @@
 #include "base/memory/ref_counted.h"
 #include "base/time/time.h"
 #include "content/public/browser/utility_process_host_client.h"
+#include "crypto/secure_hash.h"

[asargent_no_longer_on_chrome, 2015/02/03 00:42:55]

nit: I think you can just add a forward declare below and move the #include to
the .cc file. (Similar to how we do for base::DictionaryValue,
base::SequencedTaskRunner, etc.)

+#include "extensions/browser/crx_file_info.h"
 #include "extensions/common/manifest.h"
 
 class SkBitmap;
@@ -79,7 +81,7 @@ class SandboxedUnpacker : public content::UtilityProcessHostClient {
   // |client| with the result. If |run_out_of_process| is provided, unpacking
   // is done in a sandboxed subprocess. Otherwise, it is done in-process.
   SandboxedUnpacker(
-      const base::FilePath& crx_path,
+      const CRXFileInfo& file,
       Manifest::Location location,
       int creation_flags,
       const base::FilePath& extensions_dir,
@@ -126,6 +128,7 @@ class SandboxedUnpacker : public content::UtilityProcessHostClient {
     CRX_SIGNATURE_INVALID,
     CRX_SIGNATURE_VERIFICATION_INITIALIZATION_FAILED,
     CRX_SIGNATURE_VERIFICATION_FAILED,
+    CRX_HASH_VERIFICATION_FAILED,
 
     // SandboxedUnpacker::RewriteManifestFile()
     ERROR_SERIALIZING_MANIFEST_JSON,
@@ -160,6 +163,11 @@ class SandboxedUnpacker : public content::UtilityProcessHostClient {
   // Return true on success.
   virtual bool CreateTempDirectory();
 
+  // Finalizes hash calculation and checks the result against the expected
+  // package hash. In case of mismatch, depending on the command-line option,
+  // we will either fail installation, or just update histograms.
+  bool FinalizeHash(scoped_ptr<crypto::SecureHash>& hash);
+
   // Validates the signature of the extension and extract the key to
   // |public_key_|. Returns true if the signature validates, false otherwise.
   //
@@ -202,6 +210,12 @@ class SandboxedUnpacker : public content::UtilityProcessHostClient {
   // The path to the CRX to unpack.
   base::FilePath crx_path_;
 
+  // The package hash that was reported from the Web Store.
+  std::string package_hash_;
+
+  // Whether we need to check the .crx hash sum.
+  bool check_crx_hash_;
+
   // Our client.
   scoped_refptr<SandboxedUnpackerClient> client_;