New policy protobuf protocol.

chrome/browser/policy/cloud_policy_cache.cc

+// Copyright (c) 2011 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/policy/cloud_policy_cache.h"
+
+#include <limits>
+
+#include "base/file_util.h"
+#include "base/logging.h"
+#include "base/task.h"
+#include "base/values.h"
+#include "chrome/browser/browser_thread.h"
+#include "chrome/browser/policy/proto/cloud_policy.pb.h"
+#include "chrome/browser/policy/proto/device_management_backend.pb.h"
+#include "chrome/browser/policy/proto/device_management_constants.h"
+#include "chrome/browser/policy/proto/device_management_local.pb.h"
+
+using google::protobuf::RepeatedField;
+using google::protobuf::RepeatedPtrField;
+
+// This CloudPolicyCache currently supports two protocols for the interaction
+// with DMServer: the old "DevicePolicy" format, which is being used in the
+// CrOS Pilot Program and will be deprecated afterwards, and the new
+// "CloudPolicy" format, which will be used exclusively after the public launch
+// of ChromeOS.
+
+namespace policy {
+
+// Decodes a CloudPolicySettings object into two maps with mandatory and
+// recommended settings, respectively. The implementation is generated code
+// in policy/cloud_policy_generated.cc.
+void DecodePolicy(const em::CloudPolicySettings& policy,
+                  ConfigurationPolicyProvider::PolicyMapType* mandatory,
+                  ConfigurationPolicyProvider::PolicyMapType* recommended);
+
+// Saves policy information to a file.
+class PersistPolicyTask : public Task {
+ public:
+  PersistPolicyTask(const FilePath& path,
+                    const em::CloudPolicyResponse* cloud_policy_response,
+                    const em::DevicePolicyResponse* device_policy_response,
+                    const bool is_unmanaged)
+      : path_(path),
+        cloud_policy_response_(cloud_policy_response),
+        device_policy_response_(device_policy_response),
+        is_unmanaged_(is_unmanaged) {}
+
+ private:
+  // Task override.
+  virtual void Run();
+
+  const FilePath path_;
+  scoped_ptr<const em::CloudPolicyResponse> cloud_policy_response_;
+  scoped_ptr<const em::DevicePolicyResponse> device_policy_response_;
+  const bool is_unmanaged_;
+};
+
+void PersistPolicyTask::Run() {
+  DCHECK(BrowserThread::CurrentlyOn(BrowserThread::FILE));
+  std::string data;
+  em::CachedCloudPolicyResponse cached_policy;
+  if (cloud_policy_response_.get()) {
+    cached_policy.mutable_cloud_policy()->CopyFrom(*cloud_policy_response_);
+  } else if (device_policy_response_.get()) {
+    cached_policy.mutable_device_policy()->CopyFrom(*device_policy_response_);
+    cached_policy.set_timestamp(base::Time::NowFromSystemTime().ToTimeT());
+  }
+  if (is_unmanaged_) {
+    cached_policy.set_unmanaged(true);
+    cached_policy.set_timestamp(base::Time::NowFromSystemTime().ToTimeT());
+  }
+  if (!cached_policy.SerializeToString(&data)) {
+    LOG(WARNING) << "Failed to serialize policy data";
+    return;
+  }
+
+  int size = data.size();
+  if (file_util::WriteFile(path_, data.c_str(), size) != size) {
+    LOG(WARNING) << "Failed to write " << path_.value();
+    return;
+  }
+}
+
+CloudPolicyCache::CloudPolicyCache(
+    const FilePath& backing_file_path)
+    : backing_file_path_(backing_file_path),
+      device_policy_(new DictionaryValue),
+      fresh_policy_(false),
+      is_unmanaged_(false),
+      has_device_policy_(false) {
+}
+
+CloudPolicyCache::~CloudPolicyCache() {}
+
+void CloudPolicyCache::LoadPolicyFromFile() {
+  // TODO(jkummerow): This method is doing file IO during browser startup. In
+  // the long run it would be better to delay this until the FILE thread exists.
+  if (!file_util::PathExists(backing_file_path_) || fresh_policy_) {
+    return;
+  }
+
+  // Read the protobuf from the file.
+  std::string data;
+  if (!file_util::ReadFileToString(backing_file_path_, &data)) {
+    LOG(WARNING) << "Failed to read policy data from "
+                 << backing_file_path_.value();
+    return;
+  }
+
+  em::CachedCloudPolicyResponse cached_response;
+  if (!cached_response.ParseFromArray(data.c_str(), data.size())) {
+    LOG(WARNING) << "Failed to parse policy data read from "
+                 << backing_file_path_.value();
+    return;
+  }
+  base::Time timestamp;
+  PolicyMapType mandatory_policy;
+  PolicyMapType recommended_policy;
+  is_unmanaged_ = cached_response.unmanaged();
+  if (is_unmanaged_ || cached_response.has_device_policy())
+    timestamp = base::Time::FromTimeT(cached_response.timestamp());
+  if (cached_response.has_cloud_policy()) {
+    DCHECK(!is_unmanaged_);
+    bool ok = DecodePolicyResponse(cached_response.cloud_policy(),
+                                   &mandatory_policy,
+                                   &recommended_policy,
+                                   &timestamp);
+    if (!ok) {
+      LOG(WARNING) << "Decoding policy data failed.";
+      return;
+    }
+  }
+  if (timestamp > base::Time::NowFromSystemTime()) {
+    LOG(WARNING) << "Rejected policy data from " << backing_file_path_.value()
+                 << ", file is from the future.";
+    return;
+  }
+  // Swap in the new policy information.
+  if (is_unmanaged_) {
+    base::AutoLock lock(lock_);
+    last_policy_refresh_time_ = timestamp;
+    return;
+  } else if (cached_response.has_cloud_policy()) {
+    if (!fresh_policy_) {
+      base::AutoLock lock(lock_);
+      mandatory_policy_.swap(mandatory_policy);
+      recommended_policy_.swap(recommended_policy);
+      last_policy_refresh_time_ = timestamp;
+      has_device_policy_ = false;
+    }
+  } else if (cached_response.has_device_policy()) {
+    scoped_ptr<DictionaryValue> value(
+        DecodeDevicePolicy(cached_response.device_policy()));
+    if (!fresh_policy_) {
+      base::AutoLock lock(lock_);
+      device_policy_.reset(value.release());
+      last_policy_refresh_time_ = timestamp;
+      has_device_policy_ = true;
+    }
+  }
+}
+
+bool CloudPolicyCache::SetPolicy(const em::CloudPolicyResponse& policy) {
+  DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
+  is_unmanaged_ = false;
+  base::Time timestamp;
+  PolicyMapType mandatory_policy;
+  PolicyMapType recommended_policy;
+  bool ok = DecodePolicyResponse(policy, &mandatory_policy, &recommended_policy,
+                                 &timestamp);
+  if (!ok) {
+    // TODO(jkummerow): Signal error to PolicyProvider.
+    return false;
+  }
+  const bool new_policy_differs =
+      !Equals(mandatory_policy, mandatory_policy_) ||
+      !Equals(recommended_policy, recommended_policy_);
+  {
+    base::AutoLock lock(lock_);
+    mandatory_policy_.swap(mandatory_policy);
+    recommended_policy_.swap(recommended_policy);
+    fresh_policy_ = true;
+    last_policy_refresh_time_ = timestamp;
+    has_device_policy_ = false;
+  }
+
+  if (timestamp > base::Time::NowFromSystemTime() +
+                  base::TimeDelta::FromMinutes(1)) {
+    LOG(WARNING) << "Server returned policy with timestamp from the future, "
+                    "not persisting to disk.";
+  } else {
+    em::CloudPolicyResponse* policy_copy = new em::CloudPolicyResponse;
+    policy_copy->CopyFrom(policy);
+    BrowserThread::PostTask(
+        BrowserThread::FILE,
+        FROM_HERE,
+        new PersistPolicyTask(backing_file_path_, policy_copy, NULL, false));
+  }
+  return new_policy_differs;
+}
+
+bool CloudPolicyCache::SetDevicePolicy(const em::DevicePolicyResponse& policy) {
+  DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
+  is_unmanaged_ = false;
+  DictionaryValue* value = DecodeDevicePolicy(policy);
+  const bool new_policy_differs = !(value->Equals(device_policy_.get()));
+  base::Time now(base::Time::NowFromSystemTime());
+  {
+    base::AutoLock lock(lock_);
+    device_policy_.reset(value);
+    fresh_policy_ = true;
+    last_policy_refresh_time_ = now;
+    has_device_policy_ = true;
+  }
+
+  em::DevicePolicyResponse* policy_copy = new em::DevicePolicyResponse;
+  policy_copy->CopyFrom(policy);
+  BrowserThread::PostTask(
+      BrowserThread::FILE,
+      FROM_HERE,
+      new PersistPolicyTask(backing_file_path_, NULL, policy_copy, false));
+  return new_policy_differs;
+}
+
+DictionaryValue* CloudPolicyCache::GetDevicePolicy() {
+  DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
+  base::AutoLock lock(lock_);
+  return device_policy_->DeepCopy();
+}
+
+const CloudPolicyCache::PolicyMapType*
+    CloudPolicyCache::GetMandatoryPolicy() const {
+  DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
+  return &mandatory_policy_;
+}
+
+const CloudPolicyCache::PolicyMapType*
+    CloudPolicyCache::GetRecommendedPolicy() const {
+  DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
+  return &recommended_policy_;
+}
+
+void CloudPolicyCache::SetUnmanaged() {
+  DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
+  is_unmanaged_ = true;
+  {
+    base::AutoLock lock(lock_);
+    mandatory_policy_.clear();
+    recommended_policy_.clear();
+    device_policy_.reset(new DictionaryValue);
+    last_policy_refresh_time_ = base::Time::NowFromSystemTime();
+  }
+  BrowserThread::PostTask(
+      BrowserThread::FILE,
+      FROM_HERE,
+      new PersistPolicyTask(backing_file_path_, NULL, NULL, true));
+}
+
+// static
+bool CloudPolicyCache::DecodePolicyResponse(
+    const em::CloudPolicyResponse& policy_response,
+    PolicyMapType* mandatory,
+    PolicyMapType* recommended,
+    base::Time* timestamp) {
+  std::string data = policy_response.signed_response();
+
+  if (!VerifySignature(policy_response.signature(), data,
+                       policy_response.certificate_chain())) {
+    LOG(WARNING) << "Failed to verify signature.";
+    return false;
+  }
+
+  em::SignedCloudPolicyResponse response;
+  if (!response.ParseFromArray(data.c_str(), data.size())) {
+    LOG(WARNING) << "Failed to parse SignedCloudPolicyResponse protobuf.";
+    return false;
+  }
+
+  // TODO(jkummerow): Verify response.device_token(). Needs final specification
+  // which token we're actually sending / expecting to get back.
+
+  // TODO(jkummerow): Store response.device_name(), if we decide to transfer
+  // it from the server to the client.
+
+  DCHECK(timestamp);
+  *timestamp = base::Time::FromTimeT(response.timestamp());
+  DecodePolicy(response.settings(), mandatory, recommended);
+  return true;
+}
+
+// static
+bool CloudPolicyCache::VerifySignature(
+    const std::string& signature,
+    const std::string& data,
+    const RepeatedPtrField<std::string>& certificate_chain) {
+  // TODO(jkummerow): Implement this. Non-trivial because we want to do it
+  // for all platforms -> it's enough work to deserve its own CL.
+  // Don't forget to also verify the hostname of the server against the cert.
+  return true;
+}
+
+// static
+bool CloudPolicyCache::MapEntryEquals(const PolicyMapType::value_type& a,
+                                      const PolicyMapType::value_type& b) {
+  return a.first == b.first && Value::Equals(a.second, b.second);
+}
+
+// static
+bool CloudPolicyCache::Equals(const PolicyMapType& a, const PolicyMapType& b) {
+  return a.size() == b.size() &&
+      std::equal(a.begin(), a.end(), b.begin(), MapEntryEquals);
+}
+
+// static
+Value* CloudPolicyCache::DecodeIntegerValue(google::protobuf::int64 value) {
+  if (value < std::numeric_limits<int>::min() ||
+      value > std::numeric_limits<int>::max()) {
+    LOG(WARNING) << "Integer value " << value
+                 << " out of numeric limits, ignoring.";
+    return NULL;
+  }
+
+  return Value::CreateIntegerValue(static_cast<int>(value));
+}
+
+// static
+Value* CloudPolicyCache::DecodeValue(const em::GenericValue& value) {
+  if (!value.has_value_type())
+    return NULL;
+
+  switch (value.value_type()) {
+    case em::GenericValue::VALUE_TYPE_BOOL:
+      if (value.has_bool_value())
+        return Value::CreateBooleanValue(value.bool_value());
+      return NULL;
+    case em::GenericValue::VALUE_TYPE_INT64:
+      if (value.has_int64_value())
+        return DecodeIntegerValue(value.int64_value());
+      return NULL;
+    case em::GenericValue::VALUE_TYPE_STRING:
+      if (value.has_string_value())
+        return Value::CreateStringValue(value.string_value());
+      return NULL;
+    case em::GenericValue::VALUE_TYPE_DOUBLE:
+      if (value.has_double_value())
+        return Value::CreateDoubleValue(value.double_value());
+      return NULL;
+    case em::GenericValue::VALUE_TYPE_BYTES:
+      if (value.has_bytes_value()) {
+        std::string bytes = value.bytes_value();
+        return BinaryValue::CreateWithCopiedBuffer(bytes.c_str(), bytes.size());
+      }
+      return NULL;
+    case em::GenericValue::VALUE_TYPE_BOOL_ARRAY: {
+      ListValue* list = new ListValue;
+      RepeatedField<bool>::const_iterator i;
+      for (i = value.bool_array().begin(); i != value.bool_array().end(); ++i)
+        list->Append(Value::CreateBooleanValue(*i));
+      return list;
+    }
+    case em::GenericValue::VALUE_TYPE_INT64_ARRAY: {
+      ListValue* list = new ListValue;
+      RepeatedField<google::protobuf::int64>::const_iterator i;
+      for (i = value.int64_array().begin();
+           i != value.int64_array().end(); ++i) {
+        Value* int_value = DecodeIntegerValue(*i);
+        if (int_value)
+          list->Append(int_value);
+      }
+      return list;
+    }
+    case em::GenericValue::VALUE_TYPE_STRING_ARRAY: {
+      ListValue* list = new ListValue;
+      RepeatedPtrField<std::string>::const_iterator i;
+      for (i = value.string_array().begin();
+           i != value.string_array().end(); ++i)
+        list->Append(Value::CreateStringValue(*i));
+      return list;
+    }
+    case em::GenericValue::VALUE_TYPE_DOUBLE_ARRAY: {
+      ListValue* list = new ListValue;
+      RepeatedField<double>::const_iterator i;
+      for (i = value.double_array().begin();
+           i != value.double_array().end(); ++i)
+        list->Append(Value::CreateDoubleValue(*i));
+      return list;
+    }
+    default:
+      NOTREACHED() << "Unhandled value type";
+  }
+
+  return NULL;
+}
+
+// static
+DictionaryValue* CloudPolicyCache::DecodeDevicePolicy(
+    const em::DevicePolicyResponse& policy) {
+  DictionaryValue* result = new DictionaryValue;
+  RepeatedPtrField<em::DevicePolicySetting>::const_iterator setting;
+  for (setting = policy.setting().begin();
+       setting != policy.setting().end();
+       ++setting) {
+    // Wrong policy key? Skip.
+    if (setting->policy_key().compare(kChromeDevicePolicySettingKey) != 0)
+      continue;
+
+    // No policy value? Skip.
+    if (!setting->has_policy_value())
+      continue;
+
+    // Iterate through all the name-value pairs wrapped in |setting|.
+    const em::GenericSetting& policy_value(setting->policy_value());
+    RepeatedPtrField<em::GenericNamedValue>::const_iterator named_value;
+    for (named_value = policy_value.named_value().begin();
+         named_value != policy_value.named_value().end();
+         ++named_value) {
+      if (named_value->has_value()) {
+        Value* decoded_value =
+            CloudPolicyCache::DecodeValue(named_value->value());
+        if (decoded_value)
+          result->Set(named_value->name(), decoded_value);
+      }
+    }
+  }
+  return result;
+}
+
+}  // namespace policy