[sync] Automatic bootstrapping of Sync on Win 8 from cached credentials

chrome/browser/sync/credential_cache_win.h

Index: chrome/browser/sync/credential_cache_win.h
diff --git a/chrome/browser/sync/credential_cache_win.h b/chrome/browser/sync/credential_cache_win.h
new file mode 100644
index 0000000000000000000000000000000000000000..f9c984e538646b7810c8f887315629f3ced5bf94
--- /dev/null
+++ b/chrome/browser/sync/credential_cache_win.h
@@ -0,0 +1,121 @@
+// Copyright (c) 2012 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#ifndef CHROME_BROWSER_SYNC_CREDENTIAL_CACHE_WIN_H_
+#define CHROME_BROWSER_SYNC_CREDENTIAL_CACHE_WIN_H_
+#pragma once
+
+
+#include "base/basictypes.h"
+#include "base/file_path.h"
+#include "base/memory/ref_counted.h"
+
+#include <string>

[Andrew T Wilson (Slow), 2012/06/26 23:26:13]

std includes go above project-specific includes.

[Raghu Simha, 2012/07/19 06:57:07]

Done.

+
+namespace base {
+class StringValue;
+class Value;
+}
+
+namespace csync {
+
+// Encapsulates the fields that are required in order to automatically start up
+// sync. Used on Windows 8 after the user has manually signed in to Desktop
+// or Metro, to auto-start sync on the alternate Metro or Desktop profile.
+// RefCounted so that when SyncBackendHost or SigninManager want to persist sync
+// credentials to file, they can pass in a CredentialCache object to one of the
+// Persist* helper functions defined below, and not have to worry about
+// cleaning up the object.

[Roger Tawa OOO till Jul 10th, 2012/06/27 21:23:28]

I'm not sure why you need this class.  why can't you simply use a
base::DictionaryValue?  Also, I don't see why this needs to be refcounted.

[Raghu Simha, 2012/07/19 06:57:07]

The design has changed pretty significantly. Please take a look at the new
implementation.

+class CredentialCache : public base::RefCounted<CredentialCache>{

[Roger Tawa OOO till Jul 10th, 2012/06/27 21:23:28]

space before {

+ public:
+  // Instantiates a CredentialCache object with credentials that will be
+  // persisted in |profile_dir| by one of the Persist* methods.
+  CredentialCache(const std::string& authenticated_username,
+                  const std::string& sid,
+                  const std::string& lsid,
+                  const std::string& encryption_bootstrap_token,
+                  const FilePath& profile_dir);
+
+  // Instantiates an empty CredentialCache object that will be populated by
+  // LoadCredentialsFromAlternateProfile with credentials from the alternate
+  // profile directory of |profile_dir|.
+  explicit CredentialCache(const FilePath& profile_dir);
+
+  // Returns true if |profile_dir| is the "Default" folder in Chrome's default
+  // user data directory, and false otherwise.
+  static bool IsDefaultProfileDir(const FilePath& profile_dir);
+
+  // Encrypts and base 64 encodes |plaintext|, converts the result to a

[Roger Tawa OOO till Jul 10th, 2012/06/27 21:23:28]

|plaintext| not right.  Document that the caller now owns the StringValue.

[Raghu Simha, 2012/07/19 06:57:07]

Done.

+  // StringValue, and returns the result.
+  static base::StringValue* PackCredential(const std::string& clear_text);
+
+  // Extracts a string from the Value |packed|, base 64 decodes and decrypts it,
+  // and writes the result to |unpacked|.
+  static void UnpackCredential(const base::Value* packed,

[Roger Tawa OOO till Jul 10th, 2012/06/27 21:23:28]

use a const ref?

[Raghu Simha, 2012/07/19 06:57:07]

Done.

+                               std::string* unpacked);
+
+  // Persists auth tokens to the sync credential cache in |profile_dir_|. Called
+  // by SigninManager after a successful signin. Must be run on the FILE
+  // BrowserThread, and only for the "Default" profile. Takes over ownership of

[Andrew T Wilson (Slow), 2012/06/26 23:26:13]

Nobody owns a refcounted ptr, so it's not true that it takes over ownership.

[Raghu Simha, 2012/07/19 06:57:07]

This method has been removed.

+  // |credentials|.
+  static void PersistAuthTokens(scoped_refptr<CredentialCache> credentials);
+
+  // Persists the encryption bootstrap token to the sync credential cache in
+  // |profile_dir_|. Called  by SyncBackendHost after successfully starting sync
+  // for encrypted datatypes. Must be run on the FILE BrowserThread, and only
+  // for the "Default" profile. Takes over ownership of |credentials|.

[Andrew T Wilson (Slow), 2012/06/26 23:26:13]

Nobody owns a refcounted object, so this doesn't take over ownership.

[Raghu Simha, 2012/07/19 06:57:07]

This method has been removed.

+  static void PersistEncryptionBootstrapToken(
+      scoped_refptr<CredentialCache> credentials);
+
+  // Reads sign in auth tokens and the encryption bootstrap token from the sync
+  // credential cache in the alternate profile directory on Windows 8.
+  // Called by ProfileSyncService while trying to automatically and silently
+  // start sync from cached credentials. Must be run on the FILE BrowserThread,
+  // and only for the "Default" profile.
+  static void LoadCredentialsFromAlternateProfile(
+      scoped_refptr<CredentialCache> credentials);
+
+  // Member accessors.
+  std::string authenticated_username() const { return authenticated_username_; }
+  std::string sid() const { return sid_; }
+  std::string lsid() const { return lsid_; }
+  std::string encryption_bootstrap_token() const {
+    return encryption_bootstrap_token_;
+  }

[Roger Tawa OOO till Jul 10th, 2012/06/27 21:23:28]

i would return const ref return values for all these methods.

[Raghu Simha, 2012/07/19 06:57:07]

These methods have been removed.

+
+ protected:
+  // Ensures that file operations are running on the FILE BrowserThread. Virtual
+  // so that it can be mocked by unit tests.
+  virtual bool RunningOnCorrectThread() const;

[Roger Tawa OOO till Jul 10th, 2012/06/27 21:23:28]

I think the name of this function should say "file thread"

[Raghu Simha, 2012/07/19 06:57:07]

This method has been removed.

+
+  // Ensures that |profile_dir_| is the default profile directory, since we do
+  // not cache credentials in non-default directories. Virtual so that it can
+  // be mocked by unit tests.
+  virtual bool RunningInCorrectProfileDir() const;

[Roger Tawa OOO till Jul 10th, 2012/06/27 21:23:28]

I think the name of this function should say "default profile".

[Raghu Simha, 2012/07/19 06:57:07]

This method has been removed.

+
+  // Returns the path to the sync credentials file in the default Desktop
+  // profile directory if we are running in Metro mode, and vice versa. Virtual
+  // so that it can be mocked by unit tests.
+  virtual FilePath GetCredentialPathInAlternateProfile() const;
+
+ private:
+  // RefCounted implementation.
+  friend class base::RefCounted<CredentialCache>;
+  virtual ~CredentialCache();
+
+  // Credential fields.
+  std::string authenticated_username_;
+  std::string sid_;
+  std::string lsid_;
+  std::string encryption_bootstrap_token_;
+
+  // The profile directory in which the credential cache exists.
+  FilePath profile_dir_;
+
+  DISALLOW_COPY_AND_ASSIGN(CredentialCache);
+};
+
+}  // namespace csync
+
+#endif  // CHROME_BROWSER_SYNC_CREDENTIAL_CACHE_WIN_H_