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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/sandboxed_unpacker.h"
6 
7 #include <set>
8 
9 #include "base/base64.h"
10 #include "base/bind.h"
11 #include "base/command_line.h"
12 #include "base/files/file_util.h"
13 #include "base/files/file_util_proxy.h"
14 #include "base/files/scoped_file.h"
15 #include "base/json/json_string_value_serializer.h"
16 #include "base/message_loop/message_loop.h"
17 #include "base/metrics/histogram.h"
18 #include "base/numerics/safe_conversions.h"
19 #include "base/path_service.h"
20 #include "base/sequenced_task_runner.h"
21 #include "base/strings/utf_string_conversions.h"
22 #include "base/threading/sequenced_worker_pool.h"
23 #include "chrome/browser/extensions/extension_service.h"
24 #include "chrome/common/chrome_paths.h"
25 #include "chrome/common/chrome_switches.h"
26 #include "chrome/common/chrome_utility_messages.h"
27 #include "chrome/common/extensions/chrome_utility_extensions_messages.h"
28 #include "chrome/common/extensions/extension_file_util.h"
29 #include "chrome/grit/generated_resources.h"
30 #include "components/crx_file/constants.h"
31 #include "components/crx_file/crx_file.h"
32 #include "components/crx_file/id_util.h"
33 #include "content/public/browser/browser_thread.h"
34 #include "content/public/browser/utility_process_host.h"
35 #include "content/public/common/common_param_traits.h"
36 #include "crypto/signature_verifier.h"
37 #include "extensions/common/constants.h"
38 #include "extensions/common/extension.h"
39 #include "extensions/common/extension_l10n_util.h"
40 #include "extensions/common/file_util.h"
41 #include "extensions/common/manifest_constants.h"
42 #include "extensions/common/manifest_handlers/icons_handler.h"
43 #include "third_party/skia/include/core/SkBitmap.h"
44 #include "ui/base/l10n/l10n_util.h"
45 #include "ui/gfx/codec/png_codec.h"
46 
47 using base::ASCIIToUTF16;
48 using content::BrowserThread;
49 using content::UtilityProcessHost;
50 using crx_file::CrxFile;
51 
52 // The following macro makes histograms that record the length of paths
53 // in this file much easier to read.
54 // Windows has a short max path length. If the path length to a
55 // file being unpacked from a CRX exceeds the max length, we might
56 // fail to install. To see if this is happening, see how long the
57 // path to the temp unpack directory is. See crbug.com/69693 .
58 #define PATH_LENGTH_HISTOGRAM(name, path) \
59     UMA_HISTOGRAM_CUSTOM_COUNTS(name, path.value().length(), 0, 500, 100)
60 
61 // Record a rate (kB per second) at which extensions are unpacked.
62 // Range from 1kB/s to 100mB/s.
63 #define UNPACK_RATE_HISTOGRAM(name, rate) \
64     UMA_HISTOGRAM_CUSTOM_COUNTS(name, rate, 1, 100000, 100);
65 
66 namespace extensions {
67 namespace {
68 
RecordSuccessfulUnpackTimeHistograms(const base::FilePath & crx_path,const base::TimeDelta unpack_time)69 void RecordSuccessfulUnpackTimeHistograms(
70     const base::FilePath& crx_path, const base::TimeDelta unpack_time) {
71 
72   const int64 kBytesPerKb = 1024;
73   const int64 kBytesPerMb = 1024 * 1024;
74 
75   UMA_HISTOGRAM_TIMES("Extensions.SandboxUnpackSuccessTime", unpack_time);
76 
77   // To get a sense of how CRX size impacts unpack time, record unpack
78   // time for several increments of CRX size.
79   int64 crx_file_size;
80   if (!base::GetFileSize(crx_path, &crx_file_size)) {
81     UMA_HISTOGRAM_COUNTS("Extensions.SandboxUnpackSuccessCantGetCrxSize", 1);
82     return;
83   }
84 
85   // Cast is safe as long as the number of bytes in the CRX is less than
86   // 2^31 * 2^10.
87   int crx_file_size_kb = static_cast<int>(crx_file_size / kBytesPerKb);
88   UMA_HISTOGRAM_COUNTS(
89       "Extensions.SandboxUnpackSuccessCrxSize", crx_file_size_kb);
90 
91   // We have time in seconds and file size in bytes.  We want the rate bytes are
92   // unpacked in kB/s.
93   double file_size_kb =
94       static_cast<double>(crx_file_size) / static_cast<double>(kBytesPerKb);
95   int unpack_rate_kb_per_s =
96       static_cast<int>(file_size_kb / unpack_time.InSecondsF());
97   UNPACK_RATE_HISTOGRAM("Extensions.SandboxUnpackRate", unpack_rate_kb_per_s);
98 
99   if (crx_file_size < 50.0 * kBytesPerKb) {
100     UNPACK_RATE_HISTOGRAM(
101         "Extensions.SandboxUnpackRateUnder50kB", unpack_rate_kb_per_s);
102 
103   } else if (crx_file_size < 1 * kBytesPerMb) {
104     UNPACK_RATE_HISTOGRAM(
105         "Extensions.SandboxUnpackRate50kBTo1mB", unpack_rate_kb_per_s);
106 
107   } else if (crx_file_size < 2 * kBytesPerMb) {
108     UNPACK_RATE_HISTOGRAM(
109         "Extensions.SandboxUnpackRate1To2mB", unpack_rate_kb_per_s);
110 
111   } else if (crx_file_size < 5 * kBytesPerMb) {
112     UNPACK_RATE_HISTOGRAM(
113         "Extensions.SandboxUnpackRate2To5mB", unpack_rate_kb_per_s);
114 
115   } else if (crx_file_size < 10 * kBytesPerMb) {
116     UNPACK_RATE_HISTOGRAM(
117         "Extensions.SandboxUnpackRate5To10mB", unpack_rate_kb_per_s);
118 
119   } else {
120     UNPACK_RATE_HISTOGRAM(
121         "Extensions.SandboxUnpackRateOver10mB", unpack_rate_kb_per_s);
122   }
123 }
124 
125 // Work horse for FindWritableTempLocation. Creates a temp file in the folder
126 // and uses NormalizeFilePath to check if the path is junction free.
VerifyJunctionFreeLocation(base::FilePath * temp_dir)127 bool VerifyJunctionFreeLocation(base::FilePath* temp_dir) {
128   if (temp_dir->empty())
129     return false;
130 
131   base::FilePath temp_file;
132   if (!base::CreateTemporaryFileInDir(*temp_dir, &temp_file)) {
133     LOG(ERROR) << temp_dir->value() << " is not writable";
134     return false;
135   }
136   // NormalizeFilePath requires a non-empty file, so write some data.
137   // If you change the exit points of this function please make sure all
138   // exit points delete this temp file!
139   if (base::WriteFile(temp_file, ".", 1) != 1)
140     return false;
141 
142   base::FilePath normalized_temp_file;
143   bool normalized = base::NormalizeFilePath(temp_file, &normalized_temp_file);
144   if (!normalized) {
145     // If |temp_file| contains a link, the sandbox will block al file system
146     // operations, and the install will fail.
147     LOG(ERROR) << temp_dir->value() << " seem to be on remote drive.";
148   } else {
149     *temp_dir = normalized_temp_file.DirName();
150   }
151   // Clean up the temp file.
152   base::DeleteFile(temp_file, false);
153 
154   return normalized;
155 }
156 
157 // This function tries to find a location for unpacking the extension archive
158 // that is writable and does not lie on a shared drive so that the sandboxed
159 // unpacking process can write there. If no such location exists we can not
160 // proceed and should fail.
161 // The result will be written to |temp_dir|. The function will write to this
162 // parameter even if it returns false.
FindWritableTempLocation(const base::FilePath & extensions_dir,base::FilePath * temp_dir)163 bool FindWritableTempLocation(const base::FilePath& extensions_dir,
164                               base::FilePath* temp_dir) {
165 // On ChromeOS, we will only attempt to unpack extension in cryptohome (profile)
166 // directory to provide additional security/privacy and speed up the rest of
167 // the extension install process.
168 #if !defined(OS_CHROMEOS)
169   PathService::Get(base::DIR_TEMP, temp_dir);
170   if (VerifyJunctionFreeLocation(temp_dir))
171     return true;
172 #endif
173 
174   *temp_dir = file_util::GetInstallTempDir(extensions_dir);
175   if (VerifyJunctionFreeLocation(temp_dir))
176     return true;
177   // Neither paths is link free chances are good installation will fail.
178   LOG(ERROR) << "Both the %TEMP% folder and the profile seem to be on "
179              << "remote drives or read-only. Installation can not complete!";
180   return false;
181 }
182 
183 // Read the decoded images back from the file we saved them to.
184 // |extension_path| is the path to the extension we unpacked that wrote the
185 // data. Returns true on success.
ReadImagesFromFile(const base::FilePath & extension_path,DecodedImages * images)186 bool ReadImagesFromFile(const base::FilePath& extension_path,
187                         DecodedImages* images) {
188   base::FilePath path =
189       extension_path.AppendASCII(kDecodedImagesFilename);
190   std::string file_str;
191   if (!base::ReadFileToString(path, &file_str))
192     return false;
193 
194   IPC::Message pickle(file_str.data(), file_str.size());
195   PickleIterator iter(pickle);
196   return IPC::ReadParam(&pickle, &iter, images);
197 }
198 
199 // Read the decoded message catalogs back from the file we saved them to.
200 // |extension_path| is the path to the extension we unpacked that wrote the
201 // data. Returns true on success.
ReadMessageCatalogsFromFile(const base::FilePath & extension_path,base::DictionaryValue * catalogs)202 bool ReadMessageCatalogsFromFile(const base::FilePath& extension_path,
203                                  base::DictionaryValue* catalogs) {
204   base::FilePath path = extension_path.AppendASCII(
205       kDecodedMessageCatalogsFilename);
206   std::string file_str;
207   if (!base::ReadFileToString(path, &file_str))
208     return false;
209 
210   IPC::Message pickle(file_str.data(), file_str.size());
211   PickleIterator iter(pickle);
212   return IPC::ReadParam(&pickle, &iter, catalogs);
213 }
214 
215 }  // namespace
216 
SandboxedUnpacker(const base::FilePath & crx_path,Manifest::Location location,int creation_flags,const base::FilePath & extensions_dir,const scoped_refptr<base::SequencedTaskRunner> & unpacker_io_task_runner,SandboxedUnpackerClient * client)217 SandboxedUnpacker::SandboxedUnpacker(
218     const base::FilePath& crx_path,
219     Manifest::Location location,
220     int creation_flags,
221     const base::FilePath& extensions_dir,
222     const scoped_refptr<base::SequencedTaskRunner>& unpacker_io_task_runner,
223     SandboxedUnpackerClient* client)
224     : crx_path_(crx_path),
225       client_(client),
226       extensions_dir_(extensions_dir),
227       got_response_(false),
228       location_(location),
229       creation_flags_(creation_flags),
230       unpacker_io_task_runner_(unpacker_io_task_runner) {
231 }
232 
CreateTempDirectory()233 bool SandboxedUnpacker::CreateTempDirectory() {
234   CHECK(unpacker_io_task_runner_->RunsTasksOnCurrentThread());
235 
236   base::FilePath temp_dir;
237   if (!FindWritableTempLocation(extensions_dir_, &temp_dir)) {
238     ReportFailure(
239         COULD_NOT_GET_TEMP_DIRECTORY,
240         l10n_util::GetStringFUTF16(
241             IDS_EXTENSION_PACKAGE_INSTALL_ERROR,
242             ASCIIToUTF16("COULD_NOT_GET_TEMP_DIRECTORY")));
243     return false;
244   }
245 
246   if (!temp_dir_.CreateUniqueTempDirUnderPath(temp_dir)) {
247     ReportFailure(
248         COULD_NOT_CREATE_TEMP_DIRECTORY,
249         l10n_util::GetStringFUTF16(
250             IDS_EXTENSION_PACKAGE_INSTALL_ERROR,
251             ASCIIToUTF16("COULD_NOT_CREATE_TEMP_DIRECTORY")));
252     return false;
253   }
254 
255   return true;
256 }
257 
Start()258 void SandboxedUnpacker::Start() {
259   // We assume that we are started on the thread that the client wants us to do
260   // file IO on.
261   CHECK(unpacker_io_task_runner_->RunsTasksOnCurrentThread());
262 
263   unpack_start_time_ = base::TimeTicks::Now();
264 
265   PATH_LENGTH_HISTOGRAM("Extensions.SandboxUnpackInitialCrxPathLength",
266                         crx_path_);
267   if (!CreateTempDirectory())
268     return;  // ReportFailure() already called.
269 
270   // Initialize the path that will eventually contain the unpacked extension.
271   extension_root_ = temp_dir_.path().AppendASCII(kTempExtensionName);
272   PATH_LENGTH_HISTOGRAM("Extensions.SandboxUnpackUnpackedCrxPathLength",
273                         extension_root_);
274 
275   // Extract the public key and validate the package.
276   if (!ValidateSignature())
277     return;  // ValidateSignature() already reported the error.
278 
279   // Copy the crx file into our working directory.
280   base::FilePath temp_crx_path = temp_dir_.path().Append(crx_path_.BaseName());
281   PATH_LENGTH_HISTOGRAM("Extensions.SandboxUnpackTempCrxPathLength",
282                         temp_crx_path);
283 
284   if (!base::CopyFile(crx_path_, temp_crx_path)) {
285     // Failed to copy extension file to temporary directory.
286     ReportFailure(
287         FAILED_TO_COPY_EXTENSION_FILE_TO_TEMP_DIRECTORY,
288         l10n_util::GetStringFUTF16(
289             IDS_EXTENSION_PACKAGE_INSTALL_ERROR,
290             ASCIIToUTF16("FAILED_TO_COPY_EXTENSION_FILE_TO_TEMP_DIRECTORY")));
291     return;
292   }
293 
294   // The utility process will have access to the directory passed to
295   // SandboxedUnpacker.  That directory should not contain a symlink or NTFS
296   // reparse point.  When the path is used, following the link/reparse point
297   // will cause file system access outside the sandbox path, and the sandbox
298   // will deny the operation.
299   base::FilePath link_free_crx_path;
300   if (!base::NormalizeFilePath(temp_crx_path, &link_free_crx_path)) {
301     LOG(ERROR) << "Could not get the normalized path of "
302                << temp_crx_path.value();
303     ReportFailure(
304         COULD_NOT_GET_SANDBOX_FRIENDLY_PATH,
305         l10n_util::GetStringUTF16(IDS_EXTENSION_UNPACK_FAILED));
306     return;
307   }
308   PATH_LENGTH_HISTOGRAM("Extensions.SandboxUnpackLinkFreeCrxPathLength",
309                         link_free_crx_path);
310 
311   BrowserThread::PostTask(
312       BrowserThread::IO, FROM_HERE,
313       base::Bind(
314           &SandboxedUnpacker::StartProcessOnIOThread,
315           this,
316           link_free_crx_path));
317 }
318 
~SandboxedUnpacker()319 SandboxedUnpacker::~SandboxedUnpacker() {
320 }
321 
OnMessageReceived(const IPC::Message & message)322 bool SandboxedUnpacker::OnMessageReceived(const IPC::Message& message) {
323   bool handled = true;
324   IPC_BEGIN_MESSAGE_MAP(SandboxedUnpacker, message)
325     IPC_MESSAGE_HANDLER(ChromeUtilityHostMsg_UnpackExtension_Succeeded,
326                         OnUnpackExtensionSucceeded)
327     IPC_MESSAGE_HANDLER(ChromeUtilityHostMsg_UnpackExtension_Failed,
328                         OnUnpackExtensionFailed)
329     IPC_MESSAGE_UNHANDLED(handled = false)
330   IPC_END_MESSAGE_MAP()
331   return handled;
332 }
333 
OnProcessCrashed(int exit_code)334 void SandboxedUnpacker::OnProcessCrashed(int exit_code) {
335   // Don't report crashes if they happen after we got a response.
336   if (got_response_)
337     return;
338 
339   // Utility process crashed while trying to install.
340   ReportFailure(
341      UTILITY_PROCESS_CRASHED_WHILE_TRYING_TO_INSTALL,
342      l10n_util::GetStringFUTF16(
343          IDS_EXTENSION_PACKAGE_INSTALL_ERROR,
344          ASCIIToUTF16("UTILITY_PROCESS_CRASHED_WHILE_TRYING_TO_INSTALL")) +
345        ASCIIToUTF16(". ") +
346        l10n_util::GetStringUTF16(IDS_EXTENSION_INSTALL_PROCESS_CRASHED));
347 }
348 
StartProcessOnIOThread(const base::FilePath & temp_crx_path)349 void SandboxedUnpacker::StartProcessOnIOThread(
350     const base::FilePath& temp_crx_path) {
351   UtilityProcessHost* host =
352       UtilityProcessHost::Create(this, unpacker_io_task_runner_.get());
353   // Grant the subprocess access to the entire subdir the extension file is
354   // in, so that it can unpack to that dir.
355   host->SetExposedDir(temp_crx_path.DirName());
356   host->Send(
357       new ChromeUtilityMsg_UnpackExtension(
358           temp_crx_path, extension_id_, location_, creation_flags_));
359 }
360 
OnUnpackExtensionSucceeded(const base::DictionaryValue & manifest)361 void SandboxedUnpacker::OnUnpackExtensionSucceeded(
362     const base::DictionaryValue& manifest) {
363   CHECK(unpacker_io_task_runner_->RunsTasksOnCurrentThread());
364   got_response_ = true;
365 
366   scoped_ptr<base::DictionaryValue> final_manifest(
367       RewriteManifestFile(manifest));
368   if (!final_manifest)
369     return;
370 
371   // Create an extension object that refers to the temporary location the
372   // extension was unpacked to. We use this until the extension is finally
373   // installed. For example, the install UI shows images from inside the
374   // extension.
375 
376   // Localize manifest now, so confirm UI gets correct extension name.
377 
378   // TODO(rdevlin.cronin): Continue removing std::string errors and replacing
379   // with base::string16
380   std::string utf8_error;
381   if (!extension_l10n_util::LocalizeExtension(extension_root_,
382                                               final_manifest.get(),
383                                               &utf8_error)) {
384     ReportFailure(
385         COULD_NOT_LOCALIZE_EXTENSION,
386         l10n_util::GetStringFUTF16(
387             IDS_EXTENSION_PACKAGE_ERROR_MESSAGE,
388             base::UTF8ToUTF16(utf8_error)));
389     return;
390   }
391 
392   extension_ = Extension::Create(
393       extension_root_,
394       location_,
395       *final_manifest,
396       Extension::REQUIRE_KEY | creation_flags_,
397       &utf8_error);
398 
399   if (!extension_.get()) {
400     ReportFailure(INVALID_MANIFEST,
401                   ASCIIToUTF16("Manifest is invalid: " + utf8_error));
402     return;
403   }
404 
405   SkBitmap install_icon;
406   if (!RewriteImageFiles(&install_icon))
407     return;
408 
409   if (!RewriteCatalogFiles())
410     return;
411 
412   ReportSuccess(manifest, install_icon);
413 }
414 
OnUnpackExtensionFailed(const base::string16 & error)415 void SandboxedUnpacker::OnUnpackExtensionFailed(const base::string16& error) {
416   CHECK(unpacker_io_task_runner_->RunsTasksOnCurrentThread());
417   got_response_ = true;
418   ReportFailure(
419       UNPACKER_CLIENT_FAILED,
420       l10n_util::GetStringFUTF16(
421            IDS_EXTENSION_PACKAGE_ERROR_MESSAGE,
422            error));
423 }
424 
ValidateSignature()425 bool SandboxedUnpacker::ValidateSignature() {
426   base::ScopedFILE file(base::OpenFile(crx_path_, "rb"));
427 
428   if (!file.get()) {
429     // Could not open crx file for reading.
430 #if defined (OS_WIN)
431     // On windows, get the error code.
432     uint32 error_code = ::GetLastError();
433     // TODO(skerner): Use this histogram to understand why so many
434     // windows users hit this error.  crbug.com/69693
435 
436     // Windows errors are unit32s, but all of likely errors are in
437     // [1, 1000].  See winerror.h for the meaning of specific values.
438     // Clip errors outside the expected range to a single extra value.
439     // If there are errors in that extra bucket, we will know to expand
440     // the range.
441     const uint32 kMaxErrorToSend = 1001;
442     error_code = std::min(error_code, kMaxErrorToSend);
443     UMA_HISTOGRAM_ENUMERATION("Extensions.ErrorCodeFromCrxOpen",
444                               error_code, kMaxErrorToSend);
445 #endif
446 
447     ReportFailure(
448         CRX_FILE_NOT_READABLE,
449         l10n_util::GetStringFUTF16(
450             IDS_EXTENSION_PACKAGE_ERROR_CODE,
451             ASCIIToUTF16("CRX_FILE_NOT_READABLE")));
452     return false;
453   }
454 
455   // Read and verify the header.
456   // TODO(erikkay): Yuck.  I'm not a big fan of this kind of code, but it
457   // appears that we don't have any endian/alignment aware serialization
458   // code in the code base.  So for now, this assumes that we're running
459   // on a little endian machine with 4 byte alignment.
460   CrxFile::Header header;
461   size_t len = fread(&header, 1, sizeof(header), file.get());
462   if (len < sizeof(header)) {
463     // Invalid crx header
464     ReportFailure(
465         CRX_HEADER_INVALID,
466         l10n_util::GetStringFUTF16(
467             IDS_EXTENSION_PACKAGE_ERROR_CODE,
468             ASCIIToUTF16("CRX_HEADER_INVALID")));
469     return false;
470   }
471 
472   CrxFile::Error error;
473   scoped_ptr<CrxFile> crx(CrxFile::Parse(header, &error));
474   if (!crx) {
475     switch (error) {
476       case CrxFile::kWrongMagic:
477         ReportFailure(
478             CRX_MAGIC_NUMBER_INVALID,
479             l10n_util::GetStringFUTF16(
480                 IDS_EXTENSION_PACKAGE_ERROR_CODE,
481                 ASCIIToUTF16("CRX_MAGIC_NUMBER_INVALID")));
482         break;
483       case CrxFile::kInvalidVersion:
484         // Bad version numer
485         ReportFailure(
486             CRX_VERSION_NUMBER_INVALID,
487             l10n_util::GetStringFUTF16(
488                 IDS_EXTENSION_PACKAGE_ERROR_CODE,
489                 ASCIIToUTF16("CRX_VERSION_NUMBER_INVALID")));
490         break;
491       case CrxFile::kInvalidKeyTooLarge:
492       case CrxFile::kInvalidSignatureTooLarge:
493         // Excessively large key or signature
494         ReportFailure(
495             CRX_EXCESSIVELY_LARGE_KEY_OR_SIGNATURE,
496             l10n_util::GetStringFUTF16(
497                 IDS_EXTENSION_PACKAGE_ERROR_CODE,
498                 ASCIIToUTF16("CRX_EXCESSIVELY_LARGE_KEY_OR_SIGNATURE")));
499         break;
500       case CrxFile::kInvalidKeyTooSmall:
501         // Key length is zero
502         ReportFailure(
503             CRX_ZERO_KEY_LENGTH,
504             l10n_util::GetStringFUTF16(
505                 IDS_EXTENSION_PACKAGE_ERROR_CODE,
506                 ASCIIToUTF16("CRX_ZERO_KEY_LENGTH")));
507         break;
508       case CrxFile::kInvalidSignatureTooSmall:
509         // Signature length is zero
510         ReportFailure(
511             CRX_ZERO_SIGNATURE_LENGTH,
512             l10n_util::GetStringFUTF16(
513                 IDS_EXTENSION_PACKAGE_ERROR_CODE,
514                 ASCIIToUTF16("CRX_ZERO_SIGNATURE_LENGTH")));
515         break;
516     }
517     return false;
518   }
519 
520   std::vector<uint8> key;
521   key.resize(header.key_size);
522   len = fread(&key.front(), sizeof(uint8), header.key_size, file.get());
523   if (len < header.key_size) {
524     // Invalid public key
525     ReportFailure(
526         CRX_PUBLIC_KEY_INVALID,
527         l10n_util::GetStringFUTF16(
528             IDS_EXTENSION_PACKAGE_ERROR_CODE,
529             ASCIIToUTF16("CRX_PUBLIC_KEY_INVALID")));
530     return false;
531   }
532 
533   std::vector<uint8> signature;
534   signature.resize(header.signature_size);
535   len = fread(&signature.front(), sizeof(uint8), header.signature_size,
536       file.get());
537   if (len < header.signature_size) {
538     // Invalid signature
539     ReportFailure(
540         CRX_SIGNATURE_INVALID,
541         l10n_util::GetStringFUTF16(
542             IDS_EXTENSION_PACKAGE_ERROR_CODE,
543             ASCIIToUTF16("CRX_SIGNATURE_INVALID")));
544     return false;
545   }
546 
547   crypto::SignatureVerifier verifier;
548   if (!verifier.VerifyInit(crx_file::kSignatureAlgorithm,
549                            sizeof(crx_file::kSignatureAlgorithm),
550                            &signature.front(),
551                            signature.size(),
552                            &key.front(),
553                            key.size())) {
554     // Signature verification initialization failed. This is most likely
555     // caused by a public key in the wrong format (should encode algorithm).
556     ReportFailure(
557         CRX_SIGNATURE_VERIFICATION_INITIALIZATION_FAILED,
558         l10n_util::GetStringFUTF16(
559             IDS_EXTENSION_PACKAGE_ERROR_CODE,
560             ASCIIToUTF16("CRX_SIGNATURE_VERIFICATION_INITIALIZATION_FAILED")));
561     return false;
562   }
563 
564   unsigned char buf[1 << 12];
565   while ((len = fread(buf, 1, sizeof(buf), file.get())) > 0)
566     verifier.VerifyUpdate(buf, len);
567 
568   if (!verifier.VerifyFinal()) {
569     // Signature verification failed
570     ReportFailure(
571         CRX_SIGNATURE_VERIFICATION_FAILED,
572         l10n_util::GetStringFUTF16(
573             IDS_EXTENSION_PACKAGE_ERROR_CODE,
574             ASCIIToUTF16("CRX_SIGNATURE_VERIFICATION_FAILED")));
575     return false;
576   }
577 
578   std::string public_key =
579       std::string(reinterpret_cast<char*>(&key.front()), key.size());
580   base::Base64Encode(public_key, &public_key_);
581 
582   extension_id_ = crx_file::id_util::GenerateId(public_key);
583 
584   return true;
585 }
586 
ReportFailure(FailureReason reason,const base::string16 & error)587 void SandboxedUnpacker::ReportFailure(FailureReason reason,
588                                       const base::string16& error) {
589   UMA_HISTOGRAM_ENUMERATION("Extensions.SandboxUnpackFailureReason",
590                             reason, NUM_FAILURE_REASONS);
591   UMA_HISTOGRAM_TIMES("Extensions.SandboxUnpackFailureTime",
592                       base::TimeTicks::Now() - unpack_start_time_);
593   Cleanup();
594   client_->OnUnpackFailure(error);
595 }
596 
ReportSuccess(const base::DictionaryValue & original_manifest,const SkBitmap & install_icon)597 void SandboxedUnpacker::ReportSuccess(
598     const base::DictionaryValue& original_manifest,
599     const SkBitmap& install_icon) {
600   UMA_HISTOGRAM_COUNTS("Extensions.SandboxUnpackSuccess", 1);
601 
602   RecordSuccessfulUnpackTimeHistograms(
603       crx_path_, base::TimeTicks::Now() - unpack_start_time_);
604 
605   // Client takes ownership of temporary directory and extension.
606   client_->OnUnpackSuccess(
607       temp_dir_.Take(), extension_root_, &original_manifest, extension_.get(),
608       install_icon);
609   extension_ = NULL;
610 }
611 
RewriteManifestFile(const base::DictionaryValue & manifest)612 base::DictionaryValue* SandboxedUnpacker::RewriteManifestFile(
613     const base::DictionaryValue& manifest) {
614   // Add the public key extracted earlier to the parsed manifest and overwrite
615   // the original manifest. We do this to ensure the manifest doesn't contain an
616   // exploitable bug that could be used to compromise the browser.
617   scoped_ptr<base::DictionaryValue> final_manifest(manifest.DeepCopy());
618   final_manifest->SetString(manifest_keys::kPublicKey, public_key_);
619 
620   std::string manifest_json;
621   JSONStringValueSerializer serializer(&manifest_json);
622   serializer.set_pretty_print(true);
623   if (!serializer.Serialize(*final_manifest)) {
624     // Error serializing manifest.json.
625     ReportFailure(
626         ERROR_SERIALIZING_MANIFEST_JSON,
627         l10n_util::GetStringFUTF16(
628             IDS_EXTENSION_PACKAGE_INSTALL_ERROR,
629             ASCIIToUTF16("ERROR_SERIALIZING_MANIFEST_JSON")));
630     return NULL;
631   }
632 
633   base::FilePath manifest_path =
634       extension_root_.Append(kManifestFilename);
635   int size = base::checked_cast<int>(manifest_json.size());
636   if (base::WriteFile(manifest_path, manifest_json.data(), size) != size) {
637     // Error saving manifest.json.
638     ReportFailure(
639         ERROR_SAVING_MANIFEST_JSON,
640         l10n_util::GetStringFUTF16(
641             IDS_EXTENSION_PACKAGE_INSTALL_ERROR,
642             ASCIIToUTF16("ERROR_SAVING_MANIFEST_JSON")));
643     return NULL;
644   }
645 
646   return final_manifest.release();
647 }
648 
RewriteImageFiles(SkBitmap * install_icon)649 bool SandboxedUnpacker::RewriteImageFiles(SkBitmap* install_icon) {
650   DecodedImages images;
651   if (!ReadImagesFromFile(temp_dir_.path(), &images)) {
652     // Couldn't read image data from disk.
653     ReportFailure(
654         COULD_NOT_READ_IMAGE_DATA_FROM_DISK,
655         l10n_util::GetStringFUTF16(
656             IDS_EXTENSION_PACKAGE_INSTALL_ERROR,
657             ASCIIToUTF16("COULD_NOT_READ_IMAGE_DATA_FROM_DISK")));
658     return false;
659   }
660 
661   // Delete any images that may be used by the browser.  We're going to write
662   // out our own versions of the parsed images, and we want to make sure the
663   // originals are gone for good.
664   std::set<base::FilePath> image_paths =
665       extension_file_util::GetBrowserImagePaths(extension_.get());
666   if (image_paths.size() != images.size()) {
667     // Decoded images don't match what's in the manifest.
668     ReportFailure(
669         DECODED_IMAGES_DO_NOT_MATCH_THE_MANIFEST,
670         l10n_util::GetStringFUTF16(
671             IDS_EXTENSION_PACKAGE_INSTALL_ERROR,
672             ASCIIToUTF16("DECODED_IMAGES_DO_NOT_MATCH_THE_MANIFEST")));
673     return false;
674   }
675 
676   for (std::set<base::FilePath>::iterator it = image_paths.begin();
677        it != image_paths.end(); ++it) {
678     base::FilePath path = *it;
679     if (path.IsAbsolute() || path.ReferencesParent()) {
680       // Invalid path for browser image.
681       ReportFailure(
682           INVALID_PATH_FOR_BROWSER_IMAGE,
683           l10n_util::GetStringFUTF16(
684               IDS_EXTENSION_PACKAGE_INSTALL_ERROR,
685               ASCIIToUTF16("INVALID_PATH_FOR_BROWSER_IMAGE")));
686       return false;
687     }
688     if (!base::DeleteFile(extension_root_.Append(path), false)) {
689       // Error removing old image file.
690       ReportFailure(
691           ERROR_REMOVING_OLD_IMAGE_FILE,
692           l10n_util::GetStringFUTF16(
693               IDS_EXTENSION_PACKAGE_INSTALL_ERROR,
694               ASCIIToUTF16("ERROR_REMOVING_OLD_IMAGE_FILE")));
695       return false;
696     }
697   }
698 
699   const std::string& install_icon_path =
700       IconsInfo::GetIcons(extension_.get()).Get(
701           extension_misc::EXTENSION_ICON_LARGE, ExtensionIconSet::MATCH_BIGGER);
702 
703   // Write our parsed images back to disk as well.
704   for (size_t i = 0; i < images.size(); ++i) {
705     if (BrowserThread::GetBlockingPool()->IsShutdownInProgress()) {
706       // Abort package installation if shutdown was initiated, crbug.com/235525
707       ReportFailure(
708           ABORTED_DUE_TO_SHUTDOWN,
709           l10n_util::GetStringFUTF16(
710               IDS_EXTENSION_PACKAGE_INSTALL_ERROR,
711               ASCIIToUTF16("ABORTED_DUE_TO_SHUTDOWN")));
712       return false;
713     }
714 
715     const SkBitmap& image = images[i].a;
716     base::FilePath path_suffix = images[i].b;
717     if (path_suffix.MaybeAsASCII() == install_icon_path)
718       *install_icon = image;
719 
720     if (path_suffix.IsAbsolute() || path_suffix.ReferencesParent()) {
721       // Invalid path for bitmap image.
722       ReportFailure(
723           INVALID_PATH_FOR_BITMAP_IMAGE,
724           l10n_util::GetStringFUTF16(
725               IDS_EXTENSION_PACKAGE_INSTALL_ERROR,
726               ASCIIToUTF16("INVALID_PATH_FOR_BITMAP_IMAGE")));
727       return false;
728     }
729     base::FilePath path = extension_root_.Append(path_suffix);
730 
731     std::vector<unsigned char> image_data;
732     // TODO(mpcomplete): It's lame that we're encoding all images as PNG, even
733     // though they may originally be .jpg, etc.  Figure something out.
734     // http://code.google.com/p/chromium/issues/detail?id=12459
735     if (!gfx::PNGCodec::EncodeBGRASkBitmap(image, false, &image_data)) {
736       // Error re-encoding theme image.
737       ReportFailure(
738           ERROR_RE_ENCODING_THEME_IMAGE,
739           l10n_util::GetStringFUTF16(
740               IDS_EXTENSION_PACKAGE_INSTALL_ERROR,
741               ASCIIToUTF16("ERROR_RE_ENCODING_THEME_IMAGE")));
742       return false;
743     }
744 
745     // Note: we're overwriting existing files that the utility process wrote,
746     // so we can be sure the directory exists.
747     const char* image_data_ptr = reinterpret_cast<const char*>(&image_data[0]);
748     int size = base::checked_cast<int>(image_data.size());
749     if (base::WriteFile(path, image_data_ptr, size) != size) {
750       // Error saving theme image.
751       ReportFailure(
752           ERROR_SAVING_THEME_IMAGE,
753           l10n_util::GetStringFUTF16(
754               IDS_EXTENSION_PACKAGE_INSTALL_ERROR,
755               ASCIIToUTF16("ERROR_SAVING_THEME_IMAGE")));
756       return false;
757     }
758   }
759 
760   return true;
761 }
762 
RewriteCatalogFiles()763 bool SandboxedUnpacker::RewriteCatalogFiles() {
764   base::DictionaryValue catalogs;
765   if (!ReadMessageCatalogsFromFile(temp_dir_.path(), &catalogs)) {
766     // Could not read catalog data from disk.
767     ReportFailure(
768         COULD_NOT_READ_CATALOG_DATA_FROM_DISK,
769         l10n_util::GetStringFUTF16(
770             IDS_EXTENSION_PACKAGE_INSTALL_ERROR,
771             ASCIIToUTF16("COULD_NOT_READ_CATALOG_DATA_FROM_DISK")));
772     return false;
773   }
774 
775   // Write our parsed catalogs back to disk.
776   for (base::DictionaryValue::Iterator it(catalogs);
777        !it.IsAtEnd(); it.Advance()) {
778     const base::DictionaryValue* catalog = NULL;
779     if (!it.value().GetAsDictionary(&catalog)) {
780       // Invalid catalog data.
781       ReportFailure(
782           INVALID_CATALOG_DATA,
783           l10n_util::GetStringFUTF16(
784               IDS_EXTENSION_PACKAGE_INSTALL_ERROR,
785               ASCIIToUTF16("INVALID_CATALOG_DATA")));
786       return false;
787     }
788 
789     base::FilePath relative_path = base::FilePath::FromUTF8Unsafe(it.key());
790     relative_path = relative_path.Append(kMessagesFilename);
791     if (relative_path.IsAbsolute() || relative_path.ReferencesParent()) {
792       // Invalid path for catalog.
793       ReportFailure(
794           INVALID_PATH_FOR_CATALOG,
795           l10n_util::GetStringFUTF16(
796               IDS_EXTENSION_PACKAGE_INSTALL_ERROR,
797               ASCIIToUTF16("INVALID_PATH_FOR_CATALOG")));
798       return false;
799     }
800     base::FilePath path = extension_root_.Append(relative_path);
801 
802     std::string catalog_json;
803     JSONStringValueSerializer serializer(&catalog_json);
804     serializer.set_pretty_print(true);
805     if (!serializer.Serialize(*catalog)) {
806       // Error serializing catalog.
807       ReportFailure(
808           ERROR_SERIALIZING_CATALOG,
809           l10n_util::GetStringFUTF16(
810               IDS_EXTENSION_PACKAGE_INSTALL_ERROR,
811               ASCIIToUTF16("ERROR_SERIALIZING_CATALOG")));
812       return false;
813     }
814 
815     // Note: we're overwriting existing files that the utility process read,
816     // so we can be sure the directory exists.
817     int size = base::checked_cast<int>(catalog_json.size());
818     if (base::WriteFile(path, catalog_json.c_str(), size) != size) {
819       // Error saving catalog.
820       ReportFailure(
821           ERROR_SAVING_CATALOG,
822           l10n_util::GetStringFUTF16(
823               IDS_EXTENSION_PACKAGE_INSTALL_ERROR,
824               ASCIIToUTF16("ERROR_SAVING_CATALOG")));
825       return false;
826     }
827   }
828 
829   return true;
830 }
831 
Cleanup()832 void SandboxedUnpacker::Cleanup() {
833   DCHECK(unpacker_io_task_runner_->RunsTasksOnCurrentThread());
834   if (!temp_dir_.Delete()) {
835     LOG(WARNING) << "Can not delete temp directory at "
836                  << temp_dir_.path().value();
837   }
838 }
839 
840 }  // namespace extensions
841