Expose signing key from cloud policy stores

chrome/browser/chromeos/policy/device_local_account_policy_store.cc

 // 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.
 
 #include "chrome/browser/chromeos/policy/device_local_account_policy_store.h"
 
 #include <utility>
 
 #include "base/bind.h"
 #include "base/callback.h"
@@ skipping 131 matching lines @@
             ownership_status);
   const em::PolicyData* device_policy_data =
       device_settings_service_->policy_data();
   scoped_refptr<ownership::PublicKey> key =
       device_settings_service_->GetPublicKey();
   if (!key.get() || !key->is_loaded() || !device_policy_data) {
     status_ = CloudPolicyStore::STATUS_BAD_STATE;
     NotifyStoreLoaded();
     return;
   }
+  public_key_ = key->as_string();
 
   std::unique_ptr<UserCloudPolicyValidator> validator(
       UserCloudPolicyValidator::Create(std::move(policy_response),
                                        background_task_runner()));
   validator->ValidateUsername(account_id_, false);
   validator->ValidatePolicyType(dm_protocol::kChromePublicAccountPolicyType);
   // The timestamp is verified when storing a new policy downloaded from the
   // server but not when loading a cached policy from disk.
   // See SessionManagerOperation::ValidateDeviceSettings for the rationale.
   validator->ValidateAgainstCurrentPolicy(
       policy(),
       valid_timestamp_required
           ? CloudPolicyValidatorBase::TIMESTAMP_FULLY_VALIDATED
           : CloudPolicyValidatorBase::TIMESTAMP_NOT_VALIDATED,
       CloudPolicyValidatorBase::DM_TOKEN_NOT_REQUIRED,
       CloudPolicyValidatorBase::DEVICE_ID_NOT_REQUIRED);
 
   // Validate the DMToken to match what device policy has.
   validator->ValidateDMToken(device_policy_data->request_token(),
                              CloudPolicyValidatorBase::DM_TOKEN_REQUIRED);
 
   // Validate the device id to match what device policy has.
   validator->ValidateDeviceId(device_policy_data->device_id(),
                               CloudPolicyValidatorBase::DEVICE_ID_REQUIRED);
 
   validator->ValidatePayload();
   policy::BrowserPolicyConnectorChromeOS* connector =
       g_browser_process->platform_part()->browser_policy_connector_chromeos();
-  validator->ValidateSignature(key->as_string(),
-                               GetPolicyVerificationKey(),
-                               connector->GetEnterpriseDomain(),
-                               false);
+  validator->ValidateSignature(public_key_, GetPolicyVerificationKey(),
+                               connector->GetEnterpriseDomain(), false);
   validator.release()->StartValidation(callback);
 }
 
 }  // namespace policy