chromeos: Remove SystemSaltGetter::GetSystemSaltSync

Make CryptohomeClient::GetSystemSalt asynchronous

BUG=141009

Review URL: https://codereview.chromium.org/43503003

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@231286 0039d316-1c4b-4281-b951-d872f2087c98

3 files changed, 35 insertions, 31 deletions

diff --git a/chromeos/cryptohome/system_salt_getter.cc b/chromeos/cryptohome/system_salt_getter.cc
index 1fa25a3..2a26db7 100644
--- a/chromeos/cryptohome/system_salt_getter.cc
+++ b/chromeos/cryptohome/system_salt_getter.cc
@@ -27,35 +27,43 @@ SystemSaltGetter::~SystemSaltGetter() {
 
 void SystemSaltGetter::GetSystemSalt(
     const GetSystemSaltCallback& callback) {
+  if (!system_salt_.empty()) {
+    base::MessageLoopProxy::current()->PostTask(
+        FROM_HERE, base::Bind(callback, system_salt_));
+    return;
+  }
+
   DBusThreadManager::Get()->GetCryptohomeClient()->WaitForServiceToBeAvailable(
-      base::Bind(&SystemSaltGetter::GetSystemSaltInternal,
+      base::Bind(&SystemSaltGetter::DidWaitForServiceToBeAvailable,
                  weak_ptr_factory_.GetWeakPtr(),
                  callback));
 }
 
-std::string SystemSaltGetter::GetSystemSaltSync() {
-  LoadSystemSalt();  // no-op if it's already loaded.
-  return system_salt_;
-}
-
-void SystemSaltGetter::GetSystemSaltInternal(
+void SystemSaltGetter::DidWaitForServiceToBeAvailable(
     const GetSystemSaltCallback& callback,
     bool service_is_available) {
-  LOG_IF(ERROR, !service_is_available) << "WaitForServiceToBeAvailable failed.";
-  // TODO(hashimoto): Stop using GetSystemSaltSync(). crbug.com/141009
-  callback.Run(GetSystemSaltSync());
+  if (!service_is_available) {
+    LOG(ERROR) << "WaitForServiceToBeAvailable failed.";
+    callback.Run(std::string());
+    return;
+  }
+  DBusThreadManager::Get()->GetCryptohomeClient()->GetSystemSalt(
+      base::Bind(&SystemSaltGetter::DidGetSystemSalt,
+                 weak_ptr_factory_.GetWeakPtr(),
+                 callback));
 }
 
-void SystemSaltGetter::LoadSystemSalt() {
-  if (!system_salt_.empty())
-    return;
-  std::vector<uint8> salt;
-  DBusThreadManager::Get()->GetCryptohomeClient()->GetSystemSalt(&salt);
-  if (salt.empty() || salt.size() % 2 != 0U) {
+void SystemSaltGetter::DidGetSystemSalt(const GetSystemSaltCallback& callback,
+                                        DBusMethodCallStatus call_status,
+                                        const std::vector<uint8>& system_salt) {
+  if (call_status == DBUS_METHOD_CALL_SUCCESS &&
+      !system_salt.empty() &&
+      system_salt.size() % 2 == 0U)
+    system_salt_ = ConvertRawSaltToHexString(system_salt);
+  else
     LOG(WARNING) << "System salt not available";
-    return;
-  }
-  system_salt_ = ConvertRawSaltToHexString(salt);
+
+  callback.Run(system_salt_);
 }
 
 // static
diff --git a/chromeos/cryptohome/system_salt_getter.h b/chromeos/cryptohome/system_salt_getter.h
index 1e4cf81..ee33133 100644
--- a/chromeos/cryptohome/system_salt_getter.h
+++ b/chromeos/cryptohome/system_salt_getter.h
@@ -12,6 +12,7 @@
 #include "base/callback_forward.h"
 #include "base/memory/weak_ptr.h"
 #include "chromeos/chromeos_export.h"
+#include "chromeos/dbus/dbus_method_call_status.h"
 
 namespace chromeos {
 
@@ -31,26 +32,20 @@ class CHROMEOS_EXPORT SystemSaltGetter {
   static std::string ConvertRawSaltToHexString(const std::vector<uint8>& salt);
 
   // Returns system hash in hex encoded ascii format. Note: this may return
-  // an empty string (e.g. if cryptohome is not running). It is up to the
-  // calling function to try again after a delay if desired.
+  // an empty string (e.g. errors in D-Bus layer)
   void GetSystemSalt(const GetSystemSaltCallback& callback);
 
-  // Synchronous version of GetSystemSalt().
-  // Blocks the UI thread until the Cryptohome service returns the result.
-  // DEPRECATED: DO NOT USE.
-  std::string GetSystemSaltSync();
-
  protected:
   SystemSaltGetter();
   ~SystemSaltGetter();
 
  private:
   // Used to implement GetSystemSalt().
-  void GetSystemSaltInternal(const GetSystemSaltCallback& callback,
-                             bool service_is_available);
-
-  // Loads the system salt from cryptohome and caches it.
-  void LoadSystemSalt();
+  void DidWaitForServiceToBeAvailable(const GetSystemSaltCallback& callback,
+                                      bool service_is_available);
+  void DidGetSystemSalt(const GetSystemSaltCallback& callback,
+                        DBusMethodCallStatus call_status,
+                        const std::vector<uint8>& system_salt);
 
   std::string system_salt_;
 
diff --git a/chromeos/cryptohome/system_salt_getter_unittest.cc b/chromeos/cryptohome/system_salt_getter_unittest.cc
index 84403e4..07883a0 100644
--- a/chromeos/cryptohome/system_salt_getter_unittest.cc
+++ b/chromeos/cryptohome/system_salt_getter_unittest.cc
@@ -55,6 +55,7 @@ TEST_F(SystemSaltGetterTest, GetSystemSalt) {
 
   // Service becomes available.
   fake_cryptohome_client_->SetServiceIsAvailable(true);
+  base::RunLoop().RunUntilIdle();
   const std::string expected_system_salt =
       SystemSaltGetter::ConvertRawSaltToHexString(
           FakeCryptohomeClient::GetStubSystemSalt());