components/policy/core/common/policy_loader_ios.mm

   1 // Copyright 2014 The Chromium Authors. All rights reserved.
   2 // Use of this source code is governed by a BSD-style license that can be
   3 // found in the LICENSE file.
   4
   5 #include "components/policy/core/common/policy_loader_ios.h"
   6
   7 #import <Foundation/Foundation.h>
   8 #import <UIKit/UIKit.h>
   9
  10 #include "base/bind.h"
  11 #include "base/location.h"
  12 #include "base/logging.h"
  13 #include "base/mac/scoped_nsobject.h"
  14 #include "base/metrics/histogram.h"
  15 #include "base/sequenced_task_runner.h"
  16 #include "components/policy/core/common/mac_util.h"
  17 #include "components/policy/core/common/policy_bundle.h"
  18 #include "components/policy/core/common/policy_map.h"
  19 #include "components/policy/core/common/policy_namespace.h"
  20 #include "policy/policy_constants.h"
  21
  22 // This policy loader loads a managed app configuration from the NSUserDefaults.
  23 // For example code from Apple see:
  24 // https://developer.apple.com/library/ios/samplecode/sc2279/Introduction/Intro.html
  25 // For an introduction to the API see session 301 from WWDC 2013,
  26 // "Extending Your Apps for Enterprise and Education Use":
  27 // https://developer.apple.com/videos/wwdc/2013/?id=301
  28
  29 namespace {
  30
  31 // Key in the NSUserDefaults that contains the managed app configuration.
  32 NSString* const kConfigurationKey = @"com.apple.configuration.managed";
  33
  34 // Key in the managed app configuration that contains the Chrome policy.
  35 NSString* const kChromePolicyKey = @"ChromePolicy";
  36
  37 // Key in the managed app configuration that contains the encoded Chrome policy.
  38 // This is a serialized Property List, encoded in base 64.
  39 NSString* const kEncodedChromePolicyKey = @"EncodedChromePolicy";
  40
  41 }  // namespace
  42
  43 // Helper that observes notifications for NSUserDefaults and triggers an update
  44 // at the loader on the right thread.
  45 @interface PolicyNotificationObserver : NSObject {
  46   base::Closure callback_;
  47   scoped_refptr<base::SequencedTaskRunner> taskRunner_;
  48 }
  49
  50 // Designated initializer. |callback| will be posted to |taskRunner| whenever
  51 // the NSUserDefaults change.
  52 - (id)initWithCallback:(const base::Closure&)callback
  53             taskRunner:(scoped_refptr<base::SequencedTaskRunner>)taskRunner;
  54
  55 // Invoked when the NSUserDefaults change.
  56 - (void)userDefaultsChanged:(NSNotification*)notification;
  57
  58 - (void)dealloc;
  59
  60 @end
  61
  62 @implementation PolicyNotificationObserver
  63
  64 - (id)initWithCallback:(const base::Closure&)callback
  65             taskRunner:(scoped_refptr<base::SequencedTaskRunner>)taskRunner {
  66   if ((self = [super init])) {
  67     callback_ = callback;
  68     taskRunner_ = taskRunner;
  69     [[NSNotificationCenter defaultCenter]
  70         addObserver:self
  71            selector:@selector(userDefaultsChanged:)
  72                name:NSUserDefaultsDidChangeNotification
  73              object:nil];
  74   }
  75   return self;
  76 }
  77
  78 - (void)userDefaultsChanged:(NSNotification*)notification {
  79   // This may be invoked on any thread. Post the |callback_| to the loader's
  80   // |taskRunner_| to make sure it Reloads() on the right thread.
  81   taskRunner_->PostTask(FROM_HERE, callback_);
  82 }
  83
  84 - (void)dealloc {
  85   [[NSNotificationCenter defaultCenter] removeObserver:self];
  86   [super dealloc];
  87 }
  88
  89 @end
  90
  91 namespace policy {
  92
  93 PolicyLoaderIOS::PolicyLoaderIOS(
  94     scoped_refptr<base::SequencedTaskRunner> task_runner)
  95     : AsyncPolicyLoader(task_runner),
  96       weak_factory_(this) {}
  97
  98 PolicyLoaderIOS::~PolicyLoaderIOS() {
  99   DCHECK(task_runner()->RunsTasksOnCurrentThread());
 100 }
 101
 102 void PolicyLoaderIOS::InitOnBackgroundThread() {
 103   DCHECK(task_runner()->RunsTasksOnCurrentThread());
 104   base::Closure callback = base::Bind(&PolicyLoaderIOS::UserDefaultsChanged,
 105                                       weak_factory_.GetWeakPtr());
 106   notification_observer_.reset(
 107       [[PolicyNotificationObserver alloc] initWithCallback:callback
 108                                                 taskRunner:task_runner()]);
 109 }
 110
 111 scoped_ptr<PolicyBundle> PolicyLoaderIOS::Load() {
 112   scoped_ptr<PolicyBundle> bundle(new PolicyBundle());
 113   NSDictionary* configuration = [[NSUserDefaults standardUserDefaults]
 114       dictionaryForKey:kConfigurationKey];
 115   id chromePolicy = configuration[kChromePolicyKey];
 116   id encodedChromePolicy = configuration[kEncodedChromePolicyKey];
 117
 118   if (chromePolicy && [chromePolicy isKindOfClass:[NSDictionary class]]) {
 119     LoadNSDictionaryToPolicyBundle(chromePolicy, bundle.get());
 120
 121     if (encodedChromePolicy)
 122       NSLog(@"Ignoring EncodedChromePolicy because ChromePolicy is present.");
 123   } else if (encodedChromePolicy &&
 124              [encodedChromePolicy isKindOfClass:[NSString class]]) {
 125     base::scoped_nsobject<NSData> data(
 126         [[NSData alloc] initWithBase64EncodedString:encodedChromePolicy
 127                                             options:0]);
 128     if (!data) {
 129       NSLog(@"Invalid Base64 encoding of EncodedChromePolicy");
 130     } else {
 131       NSError* error = nil;
 132       NSDictionary* properties = [NSPropertyListSerialization
 133           propertyListWithData:data.get()
 134                        options:NSPropertyListImmutable
 135                         format:NULL
 136                          error:&error];
 137       if (error) {
 138         NSLog(@"Invalid property list in EncodedChromePolicy: %@", error);
 139       } else if (!properties) {
 140         NSLog(@"Failed to deserialize a valid Property List");
 141       } else if (![properties isKindOfClass:[NSDictionary class]]) {
 142         NSLog(@"Invalid property list in EncodedChromePolicy: expected an "
 143                "NSDictionary but found %@", [properties class]);
 144       } else {
 145         LoadNSDictionaryToPolicyBundle(properties, bundle.get());
 146       }
 147     }
 148   }
 149
 150   const PolicyNamespace chrome_ns(POLICY_DOMAIN_CHROME, std::string());
 151   size_t count = bundle->Get(chrome_ns).size();
 152   UMA_HISTOGRAM_COUNTS_100("Enterprise.IOSPolicies", count);
 153
 154   return bundle.Pass();
 155 }
 156
 157 base::Time PolicyLoaderIOS::LastModificationTime() {
 158   return last_notification_time_;
 159 }
 160
 161 void PolicyLoaderIOS::UserDefaultsChanged() {
 162   // The base class coalesces multiple Reload() calls into a single Load() if
 163   // the LastModificationTime() has a small delta between Reload() calls.
 164   // This coalesces the multiple notifications sent during startup into a single
 165   // Load() call.
 166   last_notification_time_ = base::Time::Now();
 167   Reload(false);
 168 }
 169
 170 // static
 171 void PolicyLoaderIOS::LoadNSDictionaryToPolicyBundle(NSDictionary* dictionary,
 172                                                      PolicyBundle* bundle) {
 173   // NSDictionary is toll-free bridged to CFDictionaryRef, which is a
 174   // CFPropertyListRef.
 175   scoped_ptr<base::Value> value =
 176       PropertyToValue(static_cast<CFPropertyListRef>(dictionary));
 177   base::DictionaryValue* dict = NULL;
 178   if (value && value->GetAsDictionary(&dict)) {
 179     PolicyMap& map = bundle->Get(PolicyNamespace(POLICY_DOMAIN_CHROME, ""));
 180     map.LoadFrom(dict, POLICY_LEVEL_MANDATORY, POLICY_SCOPE_MACHINE,
 181                  POLICY_SOURCE_PLATFORM);
 182   }
 183 }
 184
 185 }  // namespace policy