[Sync] Add support for performing a GetKey on startup.

The functionality is behind the --sync-keystore-encryption flag, and the key
is not currently consumed by anything, but this lays the groundwork for testing
the server and client interaction.

We request a key anytime we perform a GetUpdates while the cryptographer
does not have a keystore key. But, it is considered an error to request a key
and not receive one, putting us into a state of backoff.

BUG=129665
TEST=sync_unit_tests, running against python server

Review URL: https://chromiumcodereview.appspot.com/10455012

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@149248 0039d316-1c4b-4281-b951-d872f2087c98

3 files changed, 32 insertions, 1 deletions

diff --git a/sync/util/cryptographer.cc b/sync/util/cryptographer.cc
index 2c0d794..d63166b 100644
--- a/sync/util/cryptographer.cc
+++ b/sync/util/cryptographer.cc
@@ -25,6 +25,7 @@ Cryptographer::Observer::~Observer() {}
 Cryptographer::Cryptographer(Encryptor* encryptor)
     : encryptor_(encryptor),
       default_nigori_(NULL),
+      keystore_nigori_(NULL),
       encrypted_types_(SensitiveTypes()),
       encrypt_everything_(false) {
   DCHECK(encryptor);
@@ -308,6 +309,26 @@ Cryptographer::UpdateResult Cryptographer::Update(
   return Cryptographer::SUCCESS;
 }
 
+bool Cryptographer::SetKeystoreKey(const std::string& keystore_key) {
+  if (keystore_key.empty())
+    return false;
+  KeyParams params = {"localhost", "dummy", keystore_key};
+
+  // AddKey updates the default nigori, so we save the current default and
+  // make sure the keystore_nigori_ gets updated instead.
+  NigoriMap::value_type* old_default = default_nigori_;
+  if (AddKey(params)) {
+    keystore_nigori_ = default_nigori_;
+    default_nigori_ = old_default;
+    return true;
+  }
+  return false;
+}
+
+bool Cryptographer::HasKeystoreKey() {
+  return keystore_nigori_ != NULL;
+}
+
 // Static
 ModelTypeSet Cryptographer::SensitiveTypes() {
   // Both of these have their own encryption schemes, but we include them
diff --git a/sync/util/cryptographer.h b/sync/util/cryptographer.h
index f02875a..d664020 100644
--- a/sync/util/cryptographer.h
+++ b/sync/util/cryptographer.h
@@ -179,6 +179,15 @@ class Cryptographer {
   // stored in the |pending_keys_|.
   UpdateResult Update(const sync_pb::NigoriSpecifics& nigori);
 
+  // Set the keystore-derived nigori from the provided key.
+  // Returns true if we succesfully create the keystore derived nigori from the
+  // provided key, false otherwise.
+  bool SetKeystoreKey(const std::string& keystore_key);
+
+  // Returns true if we currently have a keystore-derived nigori, false
+  // otherwise.
+  bool HasKeystoreKey();
+
   // The set of types that are always encrypted.
   static ModelTypeSet SensitiveTypes();
 
@@ -237,6 +246,7 @@ class Cryptographer {
 
   NigoriMap nigoris_;  // The Nigoris we know about, mapped by key name.
   NigoriMap::value_type* default_nigori_;  // The Nigori used for encryption.
+  NigoriMap::value_type* keystore_nigori_; // Nigori generated from keystore.
 
   scoped_ptr<sync_pb::EncryptedData> pending_keys_;
 
diff --git a/sync/util/get_session_name.cc b/sync/util/get_session_name.cc
index 99a4ce0..8c86c5c 100644
--- a/sync/util/get_session_name.cc
+++ b/sync/util/get_session_name.cc
@@ -43,7 +43,7 @@ std::string GetSessionNameSynchronously() {
 #elif defined(OS_LINUX)
   session_name = base::GetLinuxDistro();
 #elif defined(OS_MACOSX)
-  session_name = internal::GetHardwareModelName();
+//  session_name = internal::GetHardwareModelName();
 #elif defined(OS_WIN)
   session_name = internal::GetComputerName();
 #elif defined(OS_ANDROID)