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      1 // Copyright (c) 2012 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 "chrome/browser/extensions/convert_web_app.h"
      6 
      7 #include <cmath>
      8 #include <limits>
      9 #include <string>
     10 #include <vector>
     11 
     12 #include "base/base64.h"
     13 #include "base/files/file_path.h"
     14 #include "base/files/file_util.h"
     15 #include "base/files/scoped_temp_dir.h"
     16 #include "base/json/json_file_value_serializer.h"
     17 #include "base/logging.h"
     18 #include "base/numerics/safe_conversions.h"
     19 #include "base/path_service.h"
     20 #include "base/strings/stringprintf.h"
     21 #include "base/strings/utf_string_conversions.h"
     22 #include "base/time/time.h"
     23 #include "chrome/common/chrome_paths.h"
     24 #include "chrome/common/web_application_info.h"
     25 #include "crypto/sha2.h"
     26 #include "extensions/common/constants.h"
     27 #include "extensions/common/extension.h"
     28 #include "extensions/common/file_util.h"
     29 #include "extensions/common/manifest_constants.h"
     30 #include "third_party/skia/include/core/SkBitmap.h"
     31 #include "ui/gfx/codec/png_codec.h"
     32 #include "url/gurl.h"
     33 
     34 namespace extensions {
     35 
     36 namespace keys = manifest_keys;
     37 
     38 using base::Time;
     39 
     40 namespace {
     41 
     42 const char kIconsDirName[] = "icons";
     43 
     44 // Create the public key for the converted web app.
     45 //
     46 // Web apps are not signed, but the public key for an extension doubles as
     47 // its unique identity, and we need one of those. A web app's unique identity
     48 // is its manifest URL, so we hash that to create a public key. There will be
     49 // no corresponding private key, which means that these extensions cannot be
     50 // auto-updated using ExtensionUpdater.
     51 std::string GenerateKey(const GURL& app_url) {
     52   char raw[crypto::kSHA256Length] = {0};
     53   std::string key;
     54   crypto::SHA256HashString(app_url.spec().c_str(), raw,
     55                            crypto::kSHA256Length);
     56   base::Base64Encode(std::string(raw, crypto::kSHA256Length), &key);
     57   return key;
     58 }
     59 
     60 }  // namespace
     61 
     62 // Generates a version for the converted app using the current date. This isn't
     63 // really needed, but it seems like useful information.
     64 std::string ConvertTimeToExtensionVersion(const Time& create_time) {
     65   Time::Exploded create_time_exploded;
     66   create_time.UTCExplode(&create_time_exploded);
     67 
     68   double micros = static_cast<double>(
     69       (create_time_exploded.millisecond * Time::kMicrosecondsPerMillisecond) +
     70       (create_time_exploded.second * Time::kMicrosecondsPerSecond) +
     71       (create_time_exploded.minute * Time::kMicrosecondsPerMinute) +
     72       (create_time_exploded.hour * Time::kMicrosecondsPerHour));
     73   double day_fraction = micros / Time::kMicrosecondsPerDay;
     74   double stamp = day_fraction * std::numeric_limits<uint16>::max();
     75 
     76   // Ghetto-round, since VC++ doesn't have round().
     77   stamp = stamp >= (floor(stamp) + 0.5) ? (stamp + 1) : stamp;
     78 
     79   return base::StringPrintf("%i.%i.%i.%i",
     80                             create_time_exploded.year,
     81                             create_time_exploded.month,
     82                             create_time_exploded.day_of_month,
     83                             static_cast<uint16>(stamp));
     84 }
     85 
     86 scoped_refptr<Extension> ConvertWebAppToExtension(
     87     const WebApplicationInfo& web_app,
     88     const Time& create_time,
     89     const base::FilePath& extensions_dir) {
     90   base::FilePath install_temp_dir =
     91       file_util::GetInstallTempDir(extensions_dir);
     92   if (install_temp_dir.empty()) {
     93     LOG(ERROR) << "Could not get path to profile temporary directory.";
     94     return NULL;
     95   }
     96 
     97   base::ScopedTempDir temp_dir;
     98   if (!temp_dir.CreateUniqueTempDirUnderPath(install_temp_dir)) {
     99     LOG(ERROR) << "Could not create temporary directory.";
    100     return NULL;
    101   }
    102 
    103   // Create the manifest
    104   scoped_ptr<base::DictionaryValue> root(new base::DictionaryValue);
    105   root->SetString(keys::kPublicKey, GenerateKey(web_app.app_url));
    106   root->SetString(keys::kName, base::UTF16ToUTF8(web_app.title));
    107   root->SetString(keys::kVersion, ConvertTimeToExtensionVersion(create_time));
    108   root->SetString(keys::kDescription, base::UTF16ToUTF8(web_app.description));
    109   root->SetString(keys::kLaunchWebURL, web_app.app_url.spec());
    110 
    111   // Add the icons.
    112   base::DictionaryValue* icons = new base::DictionaryValue();
    113   root->Set(keys::kIcons, icons);
    114   for (size_t i = 0; i < web_app.icons.size(); ++i) {
    115     std::string size = base::StringPrintf("%i", web_app.icons[i].width);
    116     std::string icon_path = base::StringPrintf("%s/%s.png", kIconsDirName,
    117                                                size.c_str());
    118     icons->SetString(size, icon_path);
    119   }
    120 
    121   // Write the manifest.
    122   base::FilePath manifest_path = temp_dir.path().Append(kManifestFilename);
    123   JSONFileValueSerializer serializer(manifest_path);
    124   if (!serializer.Serialize(*root)) {
    125     LOG(ERROR) << "Could not serialize manifest.";
    126     return NULL;
    127   }
    128 
    129   // Write the icon files.
    130   base::FilePath icons_dir = temp_dir.path().AppendASCII(kIconsDirName);
    131   if (!base::CreateDirectory(icons_dir)) {
    132     LOG(ERROR) << "Could not create icons directory.";
    133     return NULL;
    134   }
    135   for (size_t i = 0; i < web_app.icons.size(); ++i) {
    136     // Skip unfetched bitmaps.
    137     if (web_app.icons[i].data.colorType() == kUnknown_SkColorType)
    138       continue;
    139 
    140     base::FilePath icon_file = icons_dir.AppendASCII(
    141         base::StringPrintf("%i.png", web_app.icons[i].width));
    142     std::vector<unsigned char> image_data;
    143     if (!gfx::PNGCodec::EncodeBGRASkBitmap(web_app.icons[i].data,
    144                                            false,
    145                                            &image_data)) {
    146       LOG(ERROR) << "Could not create icon file.";
    147       return NULL;
    148     }
    149 
    150     const char* image_data_ptr = reinterpret_cast<const char*>(&image_data[0]);
    151     int size = base::checked_cast<int>(image_data.size());
    152     if (base::WriteFile(icon_file, image_data_ptr, size) != size) {
    153       LOG(ERROR) << "Could not write icon file.";
    154       return NULL;
    155     }
    156   }
    157 
    158   // Finally, create the extension object to represent the unpacked directory.
    159   std::string error;
    160   scoped_refptr<Extension> extension = Extension::Create(
    161       temp_dir.path(),
    162       Manifest::INTERNAL,
    163       *root,
    164       Extension::FROM_BOOKMARK,
    165       &error);
    166   if (!extension.get()) {
    167     LOG(ERROR) << error;
    168     return NULL;
    169   }
    170 
    171   temp_dir.Take();  // The caller takes ownership of the directory.
    172   return extension;
    173 }
    174 
    175 }  // namespace extensions
    176