crypto/nss_util.cc

   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 "crypto/nss_util.h"
   6 #include "crypto/nss_util_internal.h"
   7
   8 #include <nss.h>
   9 #include <pk11pub.h>
  10 #include <plarena.h>
  11 #include <prerror.h>
  12 #include <prinit.h>
  13 #include <prtime.h>
  14 #include <secmod.h>
  15
  16 #if defined(OS_OPENBSD)
  17 #include <sys/mount.h>
  18 #include <sys/param.h>
  19 #endif
  20
  21 #include <map>
  22 #include <vector>
  23
  24 #include "base/base_paths.h"
  25 #include "base/bind.h"
  26 #include "base/cpu.h"
  27 #include "base/debug/alias.h"
  28 #include "base/debug/stack_trace.h"
  29 #include "base/environment.h"
  30 #include "base/files/file_path.h"
  31 #include "base/files/file_util.h"
  32 #include "base/lazy_instance.h"
  33 #include "base/logging.h"
  34 #include "base/memory/scoped_ptr.h"
  35 #include "base/message_loop/message_loop.h"
  36 #include "base/metrics/histogram.h"
  37 #include "base/native_library.h"
  38 #include "base/path_service.h"
  39 #include "base/stl_util.h"
  40 #include "base/strings/stringprintf.h"
  41 #include "base/threading/thread_checker.h"
  42 #include "base/threading/thread_restrictions.h"
  43 #include "base/threading/worker_pool.h"
  44 #include "build/build_config.h"
  45
  46 // USE_NSS means we use NSS for everything crypto-related.  If USE_NSS is not
  47 // defined, such as on Mac and Windows, we use NSS for SSL only -- we don't
  48 // use NSS for crypto or certificate verification, and we don't use the NSS
  49 // certificate and key databases.
  50 #if defined(USE_NSS)
  51 #include "base/synchronization/lock.h"
  52 #include "crypto/nss_crypto_module_delegate.h"
  53 #endif  // defined(USE_NSS)
  54
  55 namespace crypto {
  56
  57 namespace {
  58
  59 #if defined(OS_CHROMEOS)
  60 const char kUserNSSDatabaseName[] = "UserNSSDB";
  61
  62 // Constants for loading the Chrome OS TPM-backed PKCS #11 library.
  63 const char kChapsModuleName[] = "Chaps";
  64 const char kChapsPath[] = "libchaps.so";
  65
  66 // Fake certificate authority database used for testing.
  67 static const base::FilePath::CharType kReadOnlyCertDB[] =
  68     FILE_PATH_LITERAL("/etc/fake_root_ca/nssdb");
  69 #endif  // defined(OS_CHROMEOS)
  70
  71 std::string GetNSSErrorMessage() {
  72   std::string result;
  73   if (PR_GetErrorTextLength()) {
  74     scoped_ptr<char[]> error_text(new char[PR_GetErrorTextLength() + 1]);
  75     PRInt32 copied = PR_GetErrorText(error_text.get());
  76     result = std::string(error_text.get(), copied);
  77   } else {
  78     result = base::StringPrintf("NSS error code: %d", PR_GetError());
  79   }
  80   return result;
  81 }
  82
  83 #if defined(USE_NSS)
  84 #if !defined(OS_CHROMEOS)
  85 base::FilePath GetDefaultConfigDirectory() {
  86   base::FilePath dir;
  87   PathService::Get(base::DIR_HOME, &dir);
  88   if (dir.empty()) {
  89     LOG(ERROR) << "Failed to get home directory.";
  90     return dir;
  91   }
  92   dir = dir.AppendASCII(".pki").AppendASCII("nssdb");
  93   if (!base::CreateDirectory(dir)) {
  94     LOG(ERROR) << "Failed to create " << dir.value() << " directory.";
  95     dir.clear();
  96   }
  97   DVLOG(2) << "DefaultConfigDirectory: " << dir.value();
  98   return dir;
  99 }
 100 #endif  // !defined(IS_CHROMEOS)
 101
 102 // On non-Chrome OS platforms, return the default config directory. On Chrome OS
 103 // test images, return a read-only directory with fake root CA certs (which are
 104 // used by the local Google Accounts server mock we use when testing our login
 105 // code). On Chrome OS non-test images (where the read-only directory doesn't
 106 // exist), return an empty path.
 107 base::FilePath GetInitialConfigDirectory() {
 108 #if defined(OS_CHROMEOS)
 109   base::FilePath database_dir = base::FilePath(kReadOnlyCertDB);
 110   if (!base::PathExists(database_dir))
 111     database_dir.clear();
 112   return database_dir;
 113 #else
 114   return GetDefaultConfigDirectory();
 115 #endif  // defined(OS_CHROMEOS)
 116 }
 117
 118 // This callback for NSS forwards all requests to a caller-specified
 119 // CryptoModuleBlockingPasswordDelegate object.
 120 char* PKCS11PasswordFunc(PK11SlotInfo* slot, PRBool retry, void* arg) {
 121   crypto::CryptoModuleBlockingPasswordDelegate* delegate =
 122       reinterpret_cast<crypto::CryptoModuleBlockingPasswordDelegate*>(arg);
 123   if (delegate) {
 124     bool cancelled = false;
 125     std::string password = delegate->RequestPassword(PK11_GetTokenName(slot),
 126                                                      retry != PR_FALSE,
 127                                                      &cancelled);
 128     if (cancelled)
 129       return NULL;
 130     char* result = PORT_Strdup(password.c_str());
 131     password.replace(0, password.size(), password.size(), 0);
 132     return result;
 133   }
 134   DLOG(ERROR) << "PK11 password requested with NULL arg";
 135   return NULL;
 136 }
 137
 138 // NSS creates a local cache of the sqlite database if it detects that the
 139 // filesystem the database is on is much slower than the local disk.  The
 140 // detection doesn't work with the latest versions of sqlite, such as 3.6.22
 141 // (NSS bug https://bugzilla.mozilla.org/show_bug.cgi?id=578561).  So we set
 142 // the NSS environment variable NSS_SDB_USE_CACHE to "yes" to override NSS's
 143 // detection when database_dir is on NFS.  See http://crbug.com/48585.
 144 //
 145 // TODO(wtc): port this function to other USE_NSS platforms.  It is defined
 146 // only for OS_LINUX and OS_OPENBSD simply because the statfs structure
 147 // is OS-specific.
 148 //
 149 // Because this function sets an environment variable it must be run before we
 150 // go multi-threaded.
 151 void UseLocalCacheOfNSSDatabaseIfNFS(const base::FilePath& database_dir) {
 152   bool db_on_nfs = false;
 153 #if defined(OS_LINUX)
 154   base::FileSystemType fs_type = base::FILE_SYSTEM_UNKNOWN;
 155   if (base::GetFileSystemType(database_dir, &fs_type))
 156     db_on_nfs = (fs_type == base::FILE_SYSTEM_NFS);
 157 #elif defined(OS_OPENBSD)
 158   struct statfs buf;
 159   if (statfs(database_dir.value().c_str(), &buf) == 0)
 160     db_on_nfs = (strcmp(buf.f_fstypename, MOUNT_NFS) == 0);
 161 #else
 162   NOTIMPLEMENTED();
 163 #endif
 164
 165   if (db_on_nfs) {
 166     scoped_ptr<base::Environment> env(base::Environment::Create());
 167     static const char kUseCacheEnvVar[] = "NSS_SDB_USE_CACHE";
 168     if (!env->HasVar(kUseCacheEnvVar))
 169       env->SetVar(kUseCacheEnvVar, "yes");
 170   }
 171 }
 172
 173 #endif  // defined(USE_NSS)
 174
 175 // A singleton to initialize/deinitialize NSPR.
 176 // Separate from the NSS singleton because we initialize NSPR on the UI thread.
 177 // Now that we're leaking the singleton, we could merge back with the NSS
 178 // singleton.
 179 class NSPRInitSingleton {
 180  private:
 181   friend struct base::DefaultLazyInstanceTraits<NSPRInitSingleton>;
 182
 183   NSPRInitSingleton() {
 184     PR_Init(PR_USER_THREAD, PR_PRIORITY_NORMAL, 0);
 185   }
 186
 187   // NOTE(willchan): We don't actually execute this code since we leak NSS to
 188   // prevent non-joinable threads from using NSS after it's already been shut
 189   // down.
 190   ~NSPRInitSingleton() {
 191     PL_ArenaFinish();
 192     PRStatus prstatus = PR_Cleanup();
 193     if (prstatus != PR_SUCCESS)
 194       LOG(ERROR) << "PR_Cleanup failed; was NSPR initialized on wrong thread?";
 195   }
 196 };
 197
 198 base::LazyInstance<NSPRInitSingleton>::Leaky
 199     g_nspr_singleton = LAZY_INSTANCE_INITIALIZER;
 200
 201 // Force a crash with error info on NSS_NoDB_Init failure.
 202 void CrashOnNSSInitFailure() {
 203   int nss_error = PR_GetError();
 204   int os_error = PR_GetOSError();
 205   base::debug::Alias(&nss_error);
 206   base::debug::Alias(&os_error);
 207   LOG(ERROR) << "Error initializing NSS without a persistent database: "
 208              << GetNSSErrorMessage();
 209   LOG(FATAL) << "nss_error=" << nss_error << ", os_error=" << os_error;
 210 }
 211
 212 #if defined(OS_CHROMEOS)
 213 class ChromeOSUserData {
 214  public:
 215   explicit ChromeOSUserData(ScopedPK11Slot public_slot)
 216       : public_slot_(public_slot.Pass()),
 217         private_slot_initialization_started_(false) {}
 218   ~ChromeOSUserData() {
 219     if (public_slot_) {
 220       SECStatus status = SECMOD_CloseUserDB(public_slot_.get());
 221       if (status != SECSuccess)
 222         PLOG(ERROR) << "SECMOD_CloseUserDB failed: " << PORT_GetError();
 223     }
 224   }
 225
 226   ScopedPK11Slot GetPublicSlot() {
 227     return ScopedPK11Slot(
 228         public_slot_ ? PK11_ReferenceSlot(public_slot_.get()) : NULL);
 229   }
 230
 231   ScopedPK11Slot GetPrivateSlot(
 232       const base::Callback<void(ScopedPK11Slot)>& callback) {
 233     if (private_slot_)
 234       return ScopedPK11Slot(PK11_ReferenceSlot(private_slot_.get()));
 235     if (!callback.is_null())
 236       tpm_ready_callback_list_.push_back(callback);
 237     return ScopedPK11Slot();
 238   }
 239
 240   void SetPrivateSlot(ScopedPK11Slot private_slot) {
 241     DCHECK(!private_slot_);
 242     private_slot_ = private_slot.Pass();
 243
 244     SlotReadyCallbackList callback_list;
 245     callback_list.swap(tpm_ready_callback_list_);
 246     for (SlotReadyCallbackList::iterator i = callback_list.begin();
 247          i != callback_list.end();
 248          ++i) {
 249       (*i).Run(ScopedPK11Slot(PK11_ReferenceSlot(private_slot_.get())));
 250     }
 251   }
 252
 253   bool private_slot_initialization_started() const {
 254       return private_slot_initialization_started_;
 255   }
 256
 257   void set_private_slot_initialization_started() {
 258       private_slot_initialization_started_ = true;
 259   }
 260
 261  private:
 262   ScopedPK11Slot public_slot_;
 263   ScopedPK11Slot private_slot_;
 264
 265   bool private_slot_initialization_started_;
 266
 267   typedef std::vector<base::Callback<void(ScopedPK11Slot)> >
 268       SlotReadyCallbackList;
 269   SlotReadyCallbackList tpm_ready_callback_list_;
 270 };
 271 #endif  // defined(OS_CHROMEOS)
 272
 273 class NSSInitSingleton {
 274  public:
 275 #if defined(OS_CHROMEOS)
 276   // Used with PostTaskAndReply to pass handles to worker thread and back.
 277   struct TPMModuleAndSlot {
 278     explicit TPMModuleAndSlot(SECMODModule* init_chaps_module)
 279         : chaps_module(init_chaps_module) {}
 280     SECMODModule* chaps_module;
 281     crypto::ScopedPK11Slot tpm_slot;
 282   };
 283
 284   ScopedPK11Slot OpenPersistentNSSDBForPath(const std::string& db_name,
 285                                             const base::FilePath& path) {
 286     DCHECK(thread_checker_.CalledOnValidThread());
 287     // NSS is allowed to do IO on the current thread since dispatching
 288     // to a dedicated thread would still have the affect of blocking
 289     // the current thread, due to NSS's internal locking requirements
 290     base::ThreadRestrictions::ScopedAllowIO allow_io;
 291
 292     base::FilePath nssdb_path = path.AppendASCII(".pki").AppendASCII("nssdb");
 293     if (!base::CreateDirectory(nssdb_path)) {
 294       LOG(ERROR) << "Failed to create " << nssdb_path.value() << " directory.";
 295       return ScopedPK11Slot();
 296     }
 297     return OpenSoftwareNSSDB(nssdb_path, db_name);
 298   }
 299
 300   void EnableTPMTokenForNSS() {
 301     DCHECK(thread_checker_.CalledOnValidThread());
 302
 303     // If this gets set, then we'll use the TPM for certs with
 304     // private keys, otherwise we'll fall back to the software
 305     // implementation.
 306     tpm_token_enabled_for_nss_ = true;
 307   }
 308
 309   bool IsTPMTokenEnabledForNSS() {
 310     DCHECK(thread_checker_.CalledOnValidThread());
 311     return tpm_token_enabled_for_nss_;
 312   }
 313
 314   void InitializeTPMTokenAndSystemSlot(
 315       int system_slot_id,
 316       const base::Callback<void(bool)>& callback) {
 317     DCHECK(thread_checker_.CalledOnValidThread());
 318     // Should not be called while there is already an initialization in
 319     // progress.
 320     DCHECK(!initializing_tpm_token_);
 321     // If EnableTPMTokenForNSS hasn't been called, return false.
 322     if (!tpm_token_enabled_for_nss_) {
 323       base::MessageLoop::current()->PostTask(FROM_HERE,
 324                                              base::Bind(callback, false));
 325       return;
 326     }
 327
 328     // If everything is already initialized, then return true.
 329     // Note that only |tpm_slot_| is checked, since |chaps_module_| could be
 330     // NULL in tests while |tpm_slot_| has been set to the test DB.
 331     if (tpm_slot_) {
 332       base::MessageLoop::current()->PostTask(FROM_HERE,
 333                                              base::Bind(callback, true));
 334       return;
 335     }
 336
 337     // Note that a reference is not taken to chaps_module_. This is safe since
 338     // NSSInitSingleton is Leaky, so the reference it holds is never released.
 339     scoped_ptr<TPMModuleAndSlot> tpm_args(new TPMModuleAndSlot(chaps_module_));
 340     TPMModuleAndSlot* tpm_args_ptr = tpm_args.get();
 341     if (base::WorkerPool::PostTaskAndReply(
 342             FROM_HERE,
 343             base::Bind(&NSSInitSingleton::InitializeTPMTokenOnWorkerThread,
 344                        system_slot_id,
 345                        tpm_args_ptr),
 346             base::Bind(&NSSInitSingleton::OnInitializedTPMTokenAndSystemSlot,
 347                        base::Unretained(this),  // NSSInitSingleton is leaky
 348                        callback,
 349                        base::Passed(&tpm_args)),
 350             true /* task_is_slow */
 351             )) {
 352       initializing_tpm_token_ = true;
 353     } else {
 354       base::MessageLoop::current()->PostTask(FROM_HERE,
 355                                              base::Bind(callback, false));
 356     }
 357   }
 358
 359   static void InitializeTPMTokenOnWorkerThread(CK_SLOT_ID token_slot_id,
 360                                                TPMModuleAndSlot* tpm_args) {
 361     // This tries to load the Chaps module so NSS can talk to the hardware
 362     // TPM.
 363     if (!tpm_args->chaps_module) {
 364       DVLOG(3) << "Loading chaps...";
 365       tpm_args->chaps_module = LoadModule(
 366           kChapsModuleName,
 367           kChapsPath,
 368           // For more details on these parameters, see:
 369           // https://developer.mozilla.org/en/PKCS11_Module_Specs
 370           // slotFlags=[PublicCerts] -- Certificates and public keys can be
 371           //   read from this slot without requiring a call to C_Login.
 372           // askpw=only -- Only authenticate to the token when necessary.
 373           "NSS=\"slotParams=(0={slotFlags=[PublicCerts] askpw=only})\"");
 374     }
 375     if (tpm_args->chaps_module) {
 376       tpm_args->tpm_slot =
 377           GetTPMSlotForIdOnWorkerThread(tpm_args->chaps_module, token_slot_id);
 378     }
 379   }
 380
 381   void OnInitializedTPMTokenAndSystemSlot(
 382       const base::Callback<void(bool)>& callback,
 383       scoped_ptr<TPMModuleAndSlot> tpm_args) {
 384     DCHECK(thread_checker_.CalledOnValidThread());
 385     DVLOG(2) << "Loaded chaps: " << !!tpm_args->chaps_module
 386              << ", got tpm slot: " << !!tpm_args->tpm_slot;
 387
 388     chaps_module_ = tpm_args->chaps_module;
 389     tpm_slot_ = tpm_args->tpm_slot.Pass();
 390     if (!chaps_module_ && test_system_slot_) {
 391       // chromeos_unittests try to test the TPM initialization process. If we
 392       // have a test DB open, pretend that it is the TPM slot.
 393       tpm_slot_.reset(PK11_ReferenceSlot(test_system_slot_.get()));
 394     }
 395     initializing_tpm_token_ = false;
 396
 397     if (tpm_slot_)
 398       RunAndClearTPMReadyCallbackList();
 399
 400     callback.Run(!!tpm_slot_);
 401   }
 402
 403   void RunAndClearTPMReadyCallbackList() {
 404     TPMReadyCallbackList callback_list;
 405     callback_list.swap(tpm_ready_callback_list_);
 406     for (TPMReadyCallbackList::iterator i = callback_list.begin();
 407          i != callback_list.end();
 408          ++i) {
 409       i->Run();
 410     }
 411   }
 412
 413   bool IsTPMTokenReady(const base::Closure& callback) {
 414     if (!callback.is_null()) {
 415       // Cannot DCHECK in the general case yet, but since the callback is
 416       // a new addition to the API, DCHECK to make sure at least the new uses
 417       // don't regress.
 418       DCHECK(thread_checker_.CalledOnValidThread());
 419     } else if (!thread_checker_.CalledOnValidThread()) {
 420       // TODO(mattm): Change to DCHECK when callers have been fixed.
 421       DVLOG(1) << "Called on wrong thread.\n"
 422                << base::debug::StackTrace().ToString();
 423     }
 424
 425     if (tpm_slot_)
 426       return true;
 427
 428     if (!callback.is_null())
 429       tpm_ready_callback_list_.push_back(callback);
 430
 431     return false;
 432   }
 433
 434   // Note that CK_SLOT_ID is an unsigned long, but cryptohome gives us the slot
 435   // id as an int. This should be safe since this is only used with chaps, which
 436   // we also control.
 437   static crypto::ScopedPK11Slot GetTPMSlotForIdOnWorkerThread(
 438       SECMODModule* chaps_module,
 439       CK_SLOT_ID slot_id) {
 440     DCHECK(chaps_module);
 441
 442     DVLOG(3) << "Poking chaps module.";
 443     SECStatus rv = SECMOD_UpdateSlotList(chaps_module);
 444     if (rv != SECSuccess)
 445       PLOG(ERROR) << "SECMOD_UpdateSlotList failed: " << PORT_GetError();
 446
 447     PK11SlotInfo* slot = SECMOD_LookupSlot(chaps_module->moduleID, slot_id);
 448     if (!slot)
 449       LOG(ERROR) << "TPM slot " << slot_id << " not found.";
 450     return crypto::ScopedPK11Slot(slot);
 451   }
 452
 453   bool InitializeNSSForChromeOSUser(const std::string& username_hash,
 454                                     const base::FilePath& path) {
 455     DCHECK(thread_checker_.CalledOnValidThread());
 456     if (chromeos_user_map_.find(username_hash) != chromeos_user_map_.end()) {
 457       // This user already exists in our mapping.
 458       DVLOG(2) << username_hash << " already initialized.";
 459       return false;
 460     }
 461
 462     DVLOG(2) << "Opening NSS DB " << path.value();
 463     std::string db_name = base::StringPrintf(
 464         "%s %s", kUserNSSDatabaseName, username_hash.c_str());
 465     ScopedPK11Slot public_slot(OpenPersistentNSSDBForPath(db_name, path));
 466     chromeos_user_map_[username_hash] =
 467         new ChromeOSUserData(public_slot.Pass());
 468     return true;
 469   }
 470
 471   bool ShouldInitializeTPMForChromeOSUser(const std::string& username_hash) {
 472     DCHECK(thread_checker_.CalledOnValidThread());
 473     DCHECK(chromeos_user_map_.find(username_hash) != chromeos_user_map_.end());
 474
 475     return !chromeos_user_map_[username_hash]
 476                 ->private_slot_initialization_started();
 477   }
 478
 479   void WillInitializeTPMForChromeOSUser(const std::string& username_hash) {
 480     DCHECK(thread_checker_.CalledOnValidThread());
 481     DCHECK(chromeos_user_map_.find(username_hash) != chromeos_user_map_.end());
 482
 483     chromeos_user_map_[username_hash]
 484         ->set_private_slot_initialization_started();
 485   }
 486
 487   void InitializeTPMForChromeOSUser(const std::string& username_hash,
 488                                     CK_SLOT_ID slot_id) {
 489     DCHECK(thread_checker_.CalledOnValidThread());
 490     DCHECK(chromeos_user_map_.find(username_hash) != chromeos_user_map_.end());
 491     DCHECK(chromeos_user_map_[username_hash]->
 492                private_slot_initialization_started());
 493
 494     if (!chaps_module_)
 495       return;
 496
 497     // Note that a reference is not taken to chaps_module_. This is safe since
 498     // NSSInitSingleton is Leaky, so the reference it holds is never released.
 499     scoped_ptr<TPMModuleAndSlot> tpm_args(new TPMModuleAndSlot(chaps_module_));
 500     TPMModuleAndSlot* tpm_args_ptr = tpm_args.get();
 501     base::WorkerPool::PostTaskAndReply(
 502         FROM_HERE,
 503         base::Bind(&NSSInitSingleton::InitializeTPMTokenOnWorkerThread,
 504                    slot_id,
 505                    tpm_args_ptr),
 506         base::Bind(&NSSInitSingleton::OnInitializedTPMForChromeOSUser,
 507                    base::Unretained(this),  // NSSInitSingleton is leaky
 508                    username_hash,
 509                    base::Passed(&tpm_args)),
 510         true /* task_is_slow */
 511         );
 512   }
 513
 514   void OnInitializedTPMForChromeOSUser(const std::string& username_hash,
 515                                        scoped_ptr<TPMModuleAndSlot> tpm_args) {
 516     DCHECK(thread_checker_.CalledOnValidThread());
 517     DVLOG(2) << "Got tpm slot for " << username_hash << " "
 518              << !!tpm_args->tpm_slot;
 519     chromeos_user_map_[username_hash]->SetPrivateSlot(
 520         tpm_args->tpm_slot.Pass());
 521   }
 522
 523   void InitializePrivateSoftwareSlotForChromeOSUser(
 524       const std::string& username_hash) {
 525     DCHECK(thread_checker_.CalledOnValidThread());
 526     VLOG(1) << "using software private slot for " << username_hash;
 527     DCHECK(chromeos_user_map_.find(username_hash) != chromeos_user_map_.end());
 528     DCHECK(chromeos_user_map_[username_hash]->
 529                private_slot_initialization_started());
 530
 531     chromeos_user_map_[username_hash]->SetPrivateSlot(
 532         chromeos_user_map_[username_hash]->GetPublicSlot());
 533   }
 534
 535   ScopedPK11Slot GetPublicSlotForChromeOSUser(
 536       const std::string& username_hash) {
 537     DCHECK(thread_checker_.CalledOnValidThread());
 538
 539     if (username_hash.empty()) {
 540       DVLOG(2) << "empty username_hash";
 541       return ScopedPK11Slot();
 542     }
 543
 544     if (chromeos_user_map_.find(username_hash) == chromeos_user_map_.end()) {
 545       LOG(ERROR) << username_hash << " not initialized.";
 546       return ScopedPK11Slot();
 547     }
 548     return chromeos_user_map_[username_hash]->GetPublicSlot();
 549   }
 550
 551   ScopedPK11Slot GetPrivateSlotForChromeOSUser(
 552       const std::string& username_hash,
 553       const base::Callback<void(ScopedPK11Slot)>& callback) {
 554     DCHECK(thread_checker_.CalledOnValidThread());
 555
 556     if (username_hash.empty()) {
 557       DVLOG(2) << "empty username_hash";
 558       if (!callback.is_null()) {
 559         base::MessageLoop::current()->PostTask(
 560             FROM_HERE, base::Bind(callback, base::Passed(ScopedPK11Slot())));
 561       }
 562       return ScopedPK11Slot();
 563     }
 564
 565     DCHECK(chromeos_user_map_.find(username_hash) != chromeos_user_map_.end());
 566
 567     return chromeos_user_map_[username_hash]->GetPrivateSlot(callback);
 568   }
 569
 570   void CloseChromeOSUserForTesting(const std::string& username_hash) {
 571     DCHECK(thread_checker_.CalledOnValidThread());
 572     ChromeOSUserMap::iterator i = chromeos_user_map_.find(username_hash);
 573     DCHECK(i != chromeos_user_map_.end());
 574     delete i->second;
 575     chromeos_user_map_.erase(i);
 576   }
 577
 578   void SetSystemKeySlotForTesting(ScopedPK11Slot slot) {
 579     // Ensure that a previous value of test_system_slot_ is not overwritten.
 580     // Unsetting, i.e. setting a NULL, however is allowed.
 581     DCHECK(!slot || !test_system_slot_);
 582     test_system_slot_ = slot.Pass();
 583     if (test_system_slot_) {
 584       tpm_slot_.reset(PK11_ReferenceSlot(test_system_slot_.get()));
 585       RunAndClearTPMReadyCallbackList();
 586     } else {
 587       tpm_slot_.reset();
 588     }
 589   }
 590 #endif  // defined(OS_CHROMEOS)
 591
 592 #if !defined(OS_CHROMEOS)
 593   PK11SlotInfo* GetPersistentNSSKeySlot() {
 594     // TODO(mattm): Change to DCHECK when callers have been fixed.
 595     if (!thread_checker_.CalledOnValidThread()) {
 596       DVLOG(1) << "Called on wrong thread.\n"
 597                << base::debug::StackTrace().ToString();
 598     }
 599
 600     return PK11_GetInternalKeySlot();
 601   }
 602 #endif
 603
 604 #if defined(OS_CHROMEOS)
 605   void GetSystemNSSKeySlotCallback(
 606       const base::Callback<void(ScopedPK11Slot)>& callback) {
 607     callback.Run(ScopedPK11Slot(PK11_ReferenceSlot(tpm_slot_.get())));
 608   }
 609
 610   ScopedPK11Slot GetSystemNSSKeySlot(
 611       const base::Callback<void(ScopedPK11Slot)>& callback) {
 612     DCHECK(thread_checker_.CalledOnValidThread());
 613     // TODO(mattm): chromeos::TPMTokenloader always calls
 614     // InitializeTPMTokenAndSystemSlot with slot 0.  If the system slot is
 615     // disabled, tpm_slot_ will be the first user's slot instead. Can that be
 616     // detected and return NULL instead?
 617
 618     base::Closure wrapped_callback;
 619     if (!callback.is_null()) {
 620       wrapped_callback =
 621           base::Bind(&NSSInitSingleton::GetSystemNSSKeySlotCallback,
 622                      base::Unretained(this) /* singleton is leaky */,
 623                      callback);
 624     }
 625     if (IsTPMTokenReady(wrapped_callback))
 626       return ScopedPK11Slot(PK11_ReferenceSlot(tpm_slot_.get()));
 627     return ScopedPK11Slot();
 628   }
 629 #endif
 630
 631 #if defined(USE_NSS)
 632   base::Lock* write_lock() {
 633     return &write_lock_;
 634   }
 635 #endif  // defined(USE_NSS)
 636
 637   // This method is used to force NSS to be initialized without a DB.
 638   // Call this method before NSSInitSingleton() is constructed.
 639   static void ForceNoDBInit() {
 640     force_nodb_init_ = true;
 641   }
 642
 643  private:
 644   friend struct base::DefaultLazyInstanceTraits<NSSInitSingleton>;
 645
 646   NSSInitSingleton()
 647       : tpm_token_enabled_for_nss_(false),
 648         initializing_tpm_token_(false),
 649         chaps_module_(NULL),
 650         root_(NULL) {
 651     base::TimeTicks start_time = base::TimeTicks::Now();
 652
 653     // It's safe to construct on any thread, since LazyInstance will prevent any
 654     // other threads from accessing until the constructor is done.
 655     thread_checker_.DetachFromThread();
 656
 657     DisableAESNIIfNeeded();
 658
 659     EnsureNSPRInit();
 660
 661     // We *must* have NSS >= 3.14.3.
 662     COMPILE_ASSERT(
 663         (NSS_VMAJOR == 3 && NSS_VMINOR == 14 && NSS_VPATCH >= 3) ||
 664         (NSS_VMAJOR == 3 && NSS_VMINOR > 14) ||
 665         (NSS_VMAJOR > 3),
 666         nss_version_check_failed);
 667     // Also check the run-time NSS version.
 668     // NSS_VersionCheck is a >= check, not strict equality.
 669     if (!NSS_VersionCheck("3.14.3")) {
 670       LOG(FATAL) << "NSS_VersionCheck(\"3.14.3\") failed. NSS >= 3.14.3 is "
 671                     "required. Please upgrade to the latest NSS, and if you "
 672                     "still get this error, contact your distribution "
 673                     "maintainer.";
 674     }
 675
 676     SECStatus status = SECFailure;
 677     bool nodb_init = force_nodb_init_;
 678
 679 #if !defined(USE_NSS)
 680     // Use the system certificate store, so initialize NSS without database.
 681     nodb_init = true;
 682 #endif
 683
 684     if (nodb_init) {
 685       status = NSS_NoDB_Init(NULL);
 686       if (status != SECSuccess) {
 687         CrashOnNSSInitFailure();
 688         return;
 689       }
 690 #if defined(OS_IOS)
 691       root_ = InitDefaultRootCerts();
 692 #endif  // defined(OS_IOS)
 693     } else {
 694 #if defined(USE_NSS)
 695       base::FilePath database_dir = GetInitialConfigDirectory();
 696       if (!database_dir.empty()) {
 697         // This duplicates the work which should have been done in
 698         // EarlySetupForNSSInit. However, this function is idempotent so
 699         // there's no harm done.
 700         UseLocalCacheOfNSSDatabaseIfNFS(database_dir);
 701
 702         // Initialize with a persistent database (likely, ~/.pki/nssdb).
 703         // Use "sql:" which can be shared by multiple processes safely.
 704         std::string nss_config_dir =
 705             base::StringPrintf("sql:%s", database_dir.value().c_str());
 706 #if defined(OS_CHROMEOS)
 707         status = NSS_Init(nss_config_dir.c_str());
 708 #else
 709         status = NSS_InitReadWrite(nss_config_dir.c_str());
 710 #endif
 711         if (status != SECSuccess) {
 712           LOG(ERROR) << "Error initializing NSS with a persistent "
 713                         "database (" << nss_config_dir
 714                      << "): " << GetNSSErrorMessage();
 715         }
 716       }
 717       if (status != SECSuccess) {
 718         VLOG(1) << "Initializing NSS without a persistent database.";
 719         status = NSS_NoDB_Init(NULL);
 720         if (status != SECSuccess) {
 721           CrashOnNSSInitFailure();
 722           return;
 723         }
 724       }
 725
 726       PK11_SetPasswordFunc(PKCS11PasswordFunc);
 727
 728       // If we haven't initialized the password for the NSS databases,
 729       // initialize an empty-string password so that we don't need to
 730       // log in.
 731       PK11SlotInfo* slot = PK11_GetInternalKeySlot();
 732       if (slot) {
 733         // PK11_InitPin may write to the keyDB, but no other thread can use NSS
 734         // yet, so we don't need to lock.
 735         if (PK11_NeedUserInit(slot))
 736           PK11_InitPin(slot, NULL, NULL);
 737         PK11_FreeSlot(slot);
 738       }
 739
 740       root_ = InitDefaultRootCerts();
 741 #endif  // defined(USE_NSS)
 742     }
 743
 744     // Disable MD5 certificate signatures. (They are disabled by default in
 745     // NSS 3.14.)
 746     NSS_SetAlgorithmPolicy(SEC_OID_MD5, 0, NSS_USE_ALG_IN_CERT_SIGNATURE);
 747     NSS_SetAlgorithmPolicy(SEC_OID_PKCS1_MD5_WITH_RSA_ENCRYPTION,
 748                            0, NSS_USE_ALG_IN_CERT_SIGNATURE);
 749
 750     // The UMA bit is conditionally set for this histogram in
 751     // components/startup_metric_utils.cc .
 752     LOCAL_HISTOGRAM_CUSTOM_TIMES("Startup.SlowStartupNSSInit",
 753                                  base::TimeTicks::Now() - start_time,
 754                                  base::TimeDelta::FromMilliseconds(10),
 755                                  base::TimeDelta::FromHours(1),
 756                                  50);
 757   }
 758
 759   // NOTE(willchan): We don't actually execute this code since we leak NSS to
 760   // prevent non-joinable threads from using NSS after it's already been shut
 761   // down.
 762   ~NSSInitSingleton() {
 763 #if defined(OS_CHROMEOS)
 764     STLDeleteValues(&chromeos_user_map_);
 765 #endif
 766     tpm_slot_.reset();
 767     if (root_) {
 768       SECMOD_UnloadUserModule(root_);
 769       SECMOD_DestroyModule(root_);
 770       root_ = NULL;
 771     }
 772     if (chaps_module_) {
 773       SECMOD_UnloadUserModule(chaps_module_);
 774       SECMOD_DestroyModule(chaps_module_);
 775       chaps_module_ = NULL;
 776     }
 777
 778     SECStatus status = NSS_Shutdown();
 779     if (status != SECSuccess) {
 780       // We VLOG(1) because this failure is relatively harmless (leaking, but
 781       // we're shutting down anyway).
 782       VLOG(1) << "NSS_Shutdown failed; see http://crbug.com/4609";
 783     }
 784   }
 785
 786 #if defined(USE_NSS) || defined(OS_IOS)
 787   // Load nss's built-in root certs.
 788   SECMODModule* InitDefaultRootCerts() {
 789     SECMODModule* root = LoadModule("Root Certs", "libnssckbi.so", NULL);
 790     if (root)
 791       return root;
 792
 793     // Aw, snap.  Can't find/load root cert shared library.
 794     // This will make it hard to talk to anybody via https.
 795     // TODO(mattm): Re-add the NOTREACHED here when crbug.com/310972 is fixed.
 796     return NULL;
 797   }
 798
 799   // Load the given module for this NSS session.
 800   static SECMODModule* LoadModule(const char* name,
 801                                   const char* library_path,
 802                                   const char* params) {
 803     std::string modparams = base::StringPrintf(
 804         "name=\"%s\" library=\"%s\" %s",
 805         name, library_path, params ? params : "");
 806
 807     // Shouldn't need to const_cast here, but SECMOD doesn't properly
 808     // declare input string arguments as const.  Bug
 809     // https://bugzilla.mozilla.org/show_bug.cgi?id=642546 was filed
 810     // on NSS codebase to address this.
 811     SECMODModule* module = SECMOD_LoadUserModule(
 812         const_cast<char*>(modparams.c_str()), NULL, PR_FALSE);
 813     if (!module) {
 814       LOG(ERROR) << "Error loading " << name << " module into NSS: "
 815                  << GetNSSErrorMessage();
 816       return NULL;
 817     }
 818     if (!module->loaded) {
 819       LOG(ERROR) << "After loading " << name << ", loaded==false: "
 820                  << GetNSSErrorMessage();
 821       SECMOD_DestroyModule(module);
 822       return NULL;
 823     }
 824     return module;
 825   }
 826 #endif
 827
 828   static void DisableAESNIIfNeeded() {
 829     if (NSS_VersionCheck("3.15") && !NSS_VersionCheck("3.15.4")) {
 830       // Some versions of NSS have a bug that causes AVX instructions to be
 831       // used without testing whether XSAVE is enabled by the operating system.
 832       // In order to work around this, we disable AES-NI in NSS when we find
 833       // that |has_avx()| is false (which includes the XSAVE test). See
 834       // https://bugzilla.mozilla.org/show_bug.cgi?id=940794
 835       base::CPU cpu;
 836
 837       if (cpu.has_avx_hardware() && !cpu.has_avx()) {
 838         scoped_ptr<base::Environment> env(base::Environment::Create());
 839         env->SetVar("NSS_DISABLE_HW_AES", "1");
 840       }
 841     }
 842   }
 843
 844   // If this is set to true NSS is forced to be initialized without a DB.
 845   static bool force_nodb_init_;
 846
 847   bool tpm_token_enabled_for_nss_;
 848   bool initializing_tpm_token_;
 849   typedef std::vector<base::Closure> TPMReadyCallbackList;
 850   TPMReadyCallbackList tpm_ready_callback_list_;
 851   SECMODModule* chaps_module_;
 852   crypto::ScopedPK11Slot tpm_slot_;
 853   SECMODModule* root_;
 854 #if defined(OS_CHROMEOS)
 855   typedef std::map<std::string, ChromeOSUserData*> ChromeOSUserMap;
 856   ChromeOSUserMap chromeos_user_map_;
 857   ScopedPK11Slot test_system_slot_;
 858 #endif
 859 #if defined(USE_NSS)
 860   // TODO(davidben): When https://bugzilla.mozilla.org/show_bug.cgi?id=564011
 861   // is fixed, we will no longer need the lock.
 862   base::Lock write_lock_;
 863 #endif  // defined(USE_NSS)
 864
 865   base::ThreadChecker thread_checker_;
 866 };
 867
 868 // static
 869 bool NSSInitSingleton::force_nodb_init_ = false;
 870
 871 base::LazyInstance<NSSInitSingleton>::Leaky
 872     g_nss_singleton = LAZY_INSTANCE_INITIALIZER;
 873 }  // namespace
 874
 875 #if defined(USE_NSS)
 876 ScopedPK11Slot OpenSoftwareNSSDB(const base::FilePath& path,
 877                                  const std::string& description) {
 878   const std::string modspec =
 879       base::StringPrintf("configDir='sql:%s' tokenDescription='%s'",
 880                          path.value().c_str(),
 881                          description.c_str());
 882   PK11SlotInfo* db_slot = SECMOD_OpenUserDB(modspec.c_str());
 883   if (db_slot) {
 884     if (PK11_NeedUserInit(db_slot))
 885       PK11_InitPin(db_slot, NULL, NULL);
 886   } else {
 887     LOG(ERROR) << "Error opening persistent database (" << modspec
 888                << "): " << GetNSSErrorMessage();
 889   }
 890   return ScopedPK11Slot(db_slot);
 891 }
 892
 893 void EarlySetupForNSSInit() {
 894   base::FilePath database_dir = GetInitialConfigDirectory();
 895   if (!database_dir.empty())
 896     UseLocalCacheOfNSSDatabaseIfNFS(database_dir);
 897 }
 898 #endif
 899
 900 void EnsureNSPRInit() {
 901   g_nspr_singleton.Get();
 902 }
 903
 904 void InitNSSSafely() {
 905   // We might fork, but we haven't loaded any security modules.
 906   DisableNSSForkCheck();
 907   // If we're sandboxed, we shouldn't be able to open user security modules,
 908   // but it's more correct to tell NSS to not even try.
 909   // Loading user security modules would have security implications.
 910   ForceNSSNoDBInit();
 911   // Initialize NSS.
 912   EnsureNSSInit();
 913 }
 914
 915 void EnsureNSSInit() {
 916   // Initializing SSL causes us to do blocking IO.
 917   // Temporarily allow it until we fix
 918   //   http://code.google.com/p/chromium/issues/detail?id=59847
 919   base::ThreadRestrictions::ScopedAllowIO allow_io;
 920   g_nss_singleton.Get();
 921 }
 922
 923 void ForceNSSNoDBInit() {
 924   NSSInitSingleton::ForceNoDBInit();
 925 }
 926
 927 void DisableNSSForkCheck() {
 928   scoped_ptr<base::Environment> env(base::Environment::Create());
 929   env->SetVar("NSS_STRICT_NOFORK", "DISABLED");
 930 }
 931
 932 void LoadNSSLibraries() {
 933   // Some NSS libraries are linked dynamically so load them here.
 934 #if defined(USE_NSS)
 935   // Try to search for multiple directories to load the libraries.
 936   std::vector<base::FilePath> paths;
 937
 938   // Use relative path to Search PATH for the library files.
 939   paths.push_back(base::FilePath());
 940
 941   // For Debian derivatives NSS libraries are located here.
 942   paths.push_back(base::FilePath("/usr/lib/nss"));
 943
 944   // Ubuntu 11.10 (Oneiric) and Debian Wheezy place the libraries here.
 945 #if defined(ARCH_CPU_X86_64)
 946   paths.push_back(base::FilePath("/usr/lib/x86_64-linux-gnu/nss"));
 947 #elif defined(ARCH_CPU_X86)
 948   paths.push_back(base::FilePath("/usr/lib/i386-linux-gnu/nss"));
 949 #elif defined(ARCH_CPU_ARMEL)
 950 #if defined(__ARM_PCS_VFP)
 951   paths.push_back(base::FilePath("/usr/lib/arm-linux-gnueabihf/nss"));
 952 #else
 953   paths.push_back(base::FilePath("/usr/lib/arm-linux-gnueabi/nss"));
 954 #endif  // defined(__ARM_PCS_VFP)
 955 #elif defined(ARCH_CPU_MIPSEL)
 956   paths.push_back(base::FilePath("/usr/lib/mipsel-linux-gnu/nss"));
 957 #endif  // defined(ARCH_CPU_X86_64)
 958
 959   // A list of library files to load.
 960   std::vector<std::string> libs;
 961   libs.push_back("libsoftokn3.so");
 962   libs.push_back("libfreebl3.so");
 963
 964   // For each combination of library file and path, check for existence and
 965   // then load.
 966   size_t loaded = 0;
 967   for (size_t i = 0; i < libs.size(); ++i) {
 968     for (size_t j = 0; j < paths.size(); ++j) {
 969       base::FilePath path = paths[j].Append(libs[i]);
 970       base::NativeLibrary lib = base::LoadNativeLibrary(path, NULL);
 971       if (lib) {
 972         ++loaded;
 973         break;
 974       }
 975     }
 976   }
 977
 978   if (loaded == libs.size()) {
 979     VLOG(3) << "NSS libraries loaded.";
 980   } else {
 981     LOG(ERROR) << "Failed to load NSS libraries.";
 982   }
 983 #endif  // defined(USE_NSS)
 984 }
 985
 986 bool CheckNSSVersion(const char* version) {
 987   return !!NSS_VersionCheck(version);
 988 }
 989
 990 #if defined(USE_NSS)
 991 base::Lock* GetNSSWriteLock() {
 992   return g_nss_singleton.Get().write_lock();
 993 }
 994
 995 AutoNSSWriteLock::AutoNSSWriteLock() : lock_(GetNSSWriteLock()) {
 996   // May be NULL if the lock is not needed in our version of NSS.
 997   if (lock_)
 998     lock_->Acquire();
 999 }
1000
1001 AutoNSSWriteLock::~AutoNSSWriteLock() {
1002   if (lock_) {
1003     lock_->AssertAcquired();
1004     lock_->Release();
1005   }
1006 }
1007
1008 AutoSECMODListReadLock::AutoSECMODListReadLock()
1009       : lock_(SECMOD_GetDefaultModuleListLock()) {
1010     SECMOD_GetReadLock(lock_);
1011   }
1012
1013 AutoSECMODListReadLock::~AutoSECMODListReadLock() {
1014   SECMOD_ReleaseReadLock(lock_);
1015 }
1016 #endif  // defined(USE_NSS)
1017
1018 #if defined(OS_CHROMEOS)
1019 ScopedPK11Slot GetSystemNSSKeySlot(
1020     const base::Callback<void(ScopedPK11Slot)>& callback) {
1021   return g_nss_singleton.Get().GetSystemNSSKeySlot(callback);
1022 }
1023
1024 void SetSystemKeySlotForTesting(ScopedPK11Slot slot) {
1025   g_nss_singleton.Get().SetSystemKeySlotForTesting(slot.Pass());
1026 }
1027
1028 void EnableTPMTokenForNSS() {
1029   g_nss_singleton.Get().EnableTPMTokenForNSS();
1030 }
1031
1032 bool IsTPMTokenEnabledForNSS() {
1033   return g_nss_singleton.Get().IsTPMTokenEnabledForNSS();
1034 }
1035
1036 bool IsTPMTokenReady(const base::Closure& callback) {
1037   return g_nss_singleton.Get().IsTPMTokenReady(callback);
1038 }
1039
1040 void InitializeTPMTokenAndSystemSlot(
1041     int token_slot_id,
1042     const base::Callback<void(bool)>& callback) {
1043   g_nss_singleton.Get().InitializeTPMTokenAndSystemSlot(token_slot_id,
1044                                                         callback);
1045 }
1046
1047 bool InitializeNSSForChromeOSUser(const std::string& username_hash,
1048                                   const base::FilePath& path) {
1049   return g_nss_singleton.Get().InitializeNSSForChromeOSUser(username_hash,
1050                                                             path);
1051 }
1052
1053 bool ShouldInitializeTPMForChromeOSUser(const std::string& username_hash) {
1054   return g_nss_singleton.Get().ShouldInitializeTPMForChromeOSUser(
1055       username_hash);
1056 }
1057
1058 void WillInitializeTPMForChromeOSUser(const std::string& username_hash) {
1059   g_nss_singleton.Get().WillInitializeTPMForChromeOSUser(username_hash);
1060 }
1061
1062 void InitializeTPMForChromeOSUser(
1063     const std::string& username_hash,
1064     CK_SLOT_ID slot_id) {
1065   g_nss_singleton.Get().InitializeTPMForChromeOSUser(username_hash, slot_id);
1066 }
1067
1068 void InitializePrivateSoftwareSlotForChromeOSUser(
1069     const std::string& username_hash) {
1070   g_nss_singleton.Get().InitializePrivateSoftwareSlotForChromeOSUser(
1071       username_hash);
1072 }
1073
1074 ScopedPK11Slot GetPublicSlotForChromeOSUser(const std::string& username_hash) {
1075   return g_nss_singleton.Get().GetPublicSlotForChromeOSUser(username_hash);
1076 }
1077
1078 ScopedPK11Slot GetPrivateSlotForChromeOSUser(
1079     const std::string& username_hash,
1080     const base::Callback<void(ScopedPK11Slot)>& callback) {
1081   return g_nss_singleton.Get().GetPrivateSlotForChromeOSUser(username_hash,
1082                                                              callback);
1083 }
1084
1085 void CloseChromeOSUserForTesting(const std::string& username_hash) {
1086   g_nss_singleton.Get().CloseChromeOSUserForTesting(username_hash);
1087 }
1088 #endif  // defined(OS_CHROMEOS)
1089
1090 base::Time PRTimeToBaseTime(PRTime prtime) {
1091   return base::Time::FromInternalValue(
1092       prtime + base::Time::UnixEpoch().ToInternalValue());
1093 }
1094
1095 PRTime BaseTimeToPRTime(base::Time time) {
1096   return time.ToInternalValue() - base::Time::UnixEpoch().ToInternalValue();
1097 }
1098
1099 #if !defined(OS_CHROMEOS)
1100 PK11SlotInfo* GetPersistentNSSKeySlot() {
1101   return g_nss_singleton.Get().GetPersistentNSSKeySlot();
1102 }
1103 #endif
1104
1105 }  // namespace crypto