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/file_util.h"
  31 #include "base/files/file_path.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(
 454       const std::string& email,
 455       const std::string& username_hash,
 456       const base::FilePath& path) {
 457     DCHECK(thread_checker_.CalledOnValidThread());
 458     if (chromeos_user_map_.find(username_hash) != chromeos_user_map_.end()) {
 459       // This user already exists in our mapping.
 460       DVLOG(2) << username_hash << " already initialized.";
 461       return false;
 462     }
 463
 464     DVLOG(2) << "Opening NSS DB " << path.value();
 465     std::string db_name = base::StringPrintf(
 466         "%s %s", kUserNSSDatabaseName, username_hash.c_str());
 467     ScopedPK11Slot public_slot(OpenPersistentNSSDBForPath(db_name, path));
 468     chromeos_user_map_[username_hash] =
 469         new ChromeOSUserData(public_slot.Pass());
 470     return true;
 471   }
 472
 473   bool ShouldInitializeTPMForChromeOSUser(const std::string& username_hash) {
 474     DCHECK(thread_checker_.CalledOnValidThread());
 475     DCHECK(chromeos_user_map_.find(username_hash) != chromeos_user_map_.end());
 476
 477     return !chromeos_user_map_[username_hash]
 478                 ->private_slot_initialization_started();
 479   }
 480
 481   void WillInitializeTPMForChromeOSUser(const std::string& username_hash) {
 482     DCHECK(thread_checker_.CalledOnValidThread());
 483     DCHECK(chromeos_user_map_.find(username_hash) != chromeos_user_map_.end());
 484
 485     chromeos_user_map_[username_hash]
 486         ->set_private_slot_initialization_started();
 487   }
 488
 489   void InitializeTPMForChromeOSUser(const std::string& username_hash,
 490                                     CK_SLOT_ID slot_id) {
 491     DCHECK(thread_checker_.CalledOnValidThread());
 492     DCHECK(chromeos_user_map_.find(username_hash) != chromeos_user_map_.end());
 493     DCHECK(chromeos_user_map_[username_hash]->
 494                private_slot_initialization_started());
 495
 496     if (!chaps_module_)
 497       return;
 498
 499     // Note that a reference is not taken to chaps_module_. This is safe since
 500     // NSSInitSingleton is Leaky, so the reference it holds is never released.
 501     scoped_ptr<TPMModuleAndSlot> tpm_args(new TPMModuleAndSlot(chaps_module_));
 502     TPMModuleAndSlot* tpm_args_ptr = tpm_args.get();
 503     base::WorkerPool::PostTaskAndReply(
 504         FROM_HERE,
 505         base::Bind(&NSSInitSingleton::InitializeTPMTokenOnWorkerThread,
 506                    slot_id,
 507                    tpm_args_ptr),
 508         base::Bind(&NSSInitSingleton::OnInitializedTPMForChromeOSUser,
 509                    base::Unretained(this),  // NSSInitSingleton is leaky
 510                    username_hash,
 511                    base::Passed(&tpm_args)),
 512         true /* task_is_slow */
 513         );
 514   }
 515
 516   void OnInitializedTPMForChromeOSUser(const std::string& username_hash,
 517                                        scoped_ptr<TPMModuleAndSlot> tpm_args) {
 518     DCHECK(thread_checker_.CalledOnValidThread());
 519     DVLOG(2) << "Got tpm slot for " << username_hash << " "
 520              << !!tpm_args->tpm_slot;
 521     chromeos_user_map_[username_hash]->SetPrivateSlot(
 522         tpm_args->tpm_slot.Pass());
 523   }
 524
 525   void InitializePrivateSoftwareSlotForChromeOSUser(
 526       const std::string& username_hash) {
 527     DCHECK(thread_checker_.CalledOnValidThread());
 528     VLOG(1) << "using software private slot for " << username_hash;
 529     DCHECK(chromeos_user_map_.find(username_hash) != chromeos_user_map_.end());
 530     DCHECK(chromeos_user_map_[username_hash]->
 531                private_slot_initialization_started());
 532
 533     chromeos_user_map_[username_hash]->SetPrivateSlot(
 534         chromeos_user_map_[username_hash]->GetPublicSlot());
 535   }
 536
 537   ScopedPK11Slot GetPublicSlotForChromeOSUser(
 538       const std::string& username_hash) {
 539     DCHECK(thread_checker_.CalledOnValidThread());
 540
 541     if (username_hash.empty()) {
 542       DVLOG(2) << "empty username_hash";
 543       return ScopedPK11Slot();
 544     }
 545
 546     if (chromeos_user_map_.find(username_hash) == chromeos_user_map_.end()) {
 547       LOG(ERROR) << username_hash << " not initialized.";
 548       return ScopedPK11Slot();
 549     }
 550     return chromeos_user_map_[username_hash]->GetPublicSlot();
 551   }
 552
 553   ScopedPK11Slot GetPrivateSlotForChromeOSUser(
 554       const std::string& username_hash,
 555       const base::Callback<void(ScopedPK11Slot)>& callback) {
 556     DCHECK(thread_checker_.CalledOnValidThread());
 557
 558     if (username_hash.empty()) {
 559       DVLOG(2) << "empty username_hash";
 560       if (!callback.is_null()) {
 561         base::MessageLoop::current()->PostTask(
 562             FROM_HERE, base::Bind(callback, base::Passed(ScopedPK11Slot())));
 563       }
 564       return ScopedPK11Slot();
 565     }
 566
 567     DCHECK(chromeos_user_map_.find(username_hash) != chromeos_user_map_.end());
 568
 569     return chromeos_user_map_[username_hash]->GetPrivateSlot(callback);
 570   }
 571
 572   void CloseChromeOSUserForTesting(const std::string& username_hash) {
 573     DCHECK(thread_checker_.CalledOnValidThread());
 574     ChromeOSUserMap::iterator i = chromeos_user_map_.find(username_hash);
 575     DCHECK(i != chromeos_user_map_.end());
 576     delete i->second;
 577     chromeos_user_map_.erase(i);
 578   }
 579
 580   void SetSystemKeySlotForTesting(ScopedPK11Slot slot) {
 581     // Ensure that a previous value of test_system_slot_ is not overwritten.
 582     // Unsetting, i.e. setting a NULL, however is allowed.
 583     DCHECK(!slot || !test_system_slot_);
 584     test_system_slot_ = slot.Pass();
 585     if (test_system_slot_) {
 586       tpm_slot_.reset(PK11_ReferenceSlot(test_system_slot_.get()));
 587       RunAndClearTPMReadyCallbackList();
 588     } else {
 589       tpm_slot_.reset();
 590     }
 591   }
 592 #endif  // defined(OS_CHROMEOS)
 593
 594 #if !defined(OS_CHROMEOS)
 595   PK11SlotInfo* GetPersistentNSSKeySlot() {
 596     // TODO(mattm): Change to DCHECK when callers have been fixed.
 597     if (!thread_checker_.CalledOnValidThread()) {
 598       DVLOG(1) << "Called on wrong thread.\n"
 599                << base::debug::StackTrace().ToString();
 600     }
 601
 602     return PK11_GetInternalKeySlot();
 603   }
 604 #endif
 605
 606 #if defined(OS_CHROMEOS)
 607   void GetSystemNSSKeySlotCallback(
 608       const base::Callback<void(ScopedPK11Slot)>& callback) {
 609     callback.Run(ScopedPK11Slot(PK11_ReferenceSlot(tpm_slot_.get())));
 610   }
 611
 612   ScopedPK11Slot GetSystemNSSKeySlot(
 613       const base::Callback<void(ScopedPK11Slot)>& callback) {
 614     DCHECK(thread_checker_.CalledOnValidThread());
 615     // TODO(mattm): chromeos::TPMTokenloader always calls
 616     // InitializeTPMTokenAndSystemSlot with slot 0.  If the system slot is
 617     // disabled, tpm_slot_ will be the first user's slot instead. Can that be
 618     // detected and return NULL instead?
 619
 620     base::Closure wrapped_callback;
 621     if (!callback.is_null()) {
 622       wrapped_callback =
 623           base::Bind(&NSSInitSingleton::GetSystemNSSKeySlotCallback,
 624                      base::Unretained(this) /* singleton is leaky */,
 625                      callback);
 626     }
 627     if (IsTPMTokenReady(wrapped_callback))
 628       return ScopedPK11Slot(PK11_ReferenceSlot(tpm_slot_.get()));
 629     return ScopedPK11Slot();
 630   }
 631 #endif
 632
 633 #if defined(USE_NSS)
 634   base::Lock* write_lock() {
 635     return &write_lock_;
 636   }
 637 #endif  // defined(USE_NSS)
 638
 639   // This method is used to force NSS to be initialized without a DB.
 640   // Call this method before NSSInitSingleton() is constructed.
 641   static void ForceNoDBInit() {
 642     force_nodb_init_ = true;
 643   }
 644
 645  private:
 646   friend struct base::DefaultLazyInstanceTraits<NSSInitSingleton>;
 647
 648   NSSInitSingleton()
 649       : tpm_token_enabled_for_nss_(false),
 650         initializing_tpm_token_(false),
 651         chaps_module_(NULL),
 652         root_(NULL) {
 653     base::TimeTicks start_time = base::TimeTicks::Now();
 654
 655     // It's safe to construct on any thread, since LazyInstance will prevent any
 656     // other threads from accessing until the constructor is done.
 657     thread_checker_.DetachFromThread();
 658
 659     DisableAESNIIfNeeded();
 660
 661     EnsureNSPRInit();
 662
 663     // We *must* have NSS >= 3.14.3.
 664     COMPILE_ASSERT(
 665         (NSS_VMAJOR == 3 && NSS_VMINOR == 14 && NSS_VPATCH >= 3) ||
 666         (NSS_VMAJOR == 3 && NSS_VMINOR > 14) ||
 667         (NSS_VMAJOR > 3),
 668         nss_version_check_failed);
 669     // Also check the run-time NSS version.
 670     // NSS_VersionCheck is a >= check, not strict equality.
 671     if (!NSS_VersionCheck("3.14.3")) {
 672       LOG(FATAL) << "NSS_VersionCheck(\"3.14.3\") failed. NSS >= 3.14.3 is "
 673                     "required. Please upgrade to the latest NSS, and if you "
 674                     "still get this error, contact your distribution "
 675                     "maintainer.";
 676     }
 677
 678     SECStatus status = SECFailure;
 679     bool nodb_init = force_nodb_init_;
 680
 681 #if !defined(USE_NSS)
 682     // Use the system certificate store, so initialize NSS without database.
 683     nodb_init = true;
 684 #endif
 685
 686     if (nodb_init) {
 687       status = NSS_NoDB_Init(NULL);
 688       if (status != SECSuccess) {
 689         CrashOnNSSInitFailure();
 690         return;
 691       }
 692 #if defined(OS_IOS)
 693       root_ = InitDefaultRootCerts();
 694 #endif  // defined(OS_IOS)
 695     } else {
 696 #if defined(USE_NSS)
 697       base::FilePath database_dir = GetInitialConfigDirectory();
 698       if (!database_dir.empty()) {
 699         // This duplicates the work which should have been done in
 700         // EarlySetupForNSSInit. However, this function is idempotent so
 701         // there's no harm done.
 702         UseLocalCacheOfNSSDatabaseIfNFS(database_dir);
 703
 704         // Initialize with a persistent database (likely, ~/.pki/nssdb).
 705         // Use "sql:" which can be shared by multiple processes safely.
 706         std::string nss_config_dir =
 707             base::StringPrintf("sql:%s", database_dir.value().c_str());
 708 #if defined(OS_CHROMEOS)
 709         status = NSS_Init(nss_config_dir.c_str());
 710 #else
 711         status = NSS_InitReadWrite(nss_config_dir.c_str());
 712 #endif
 713         if (status != SECSuccess) {
 714           LOG(ERROR) << "Error initializing NSS with a persistent "
 715                         "database (" << nss_config_dir
 716                      << "): " << GetNSSErrorMessage();
 717         }
 718       }
 719       if (status != SECSuccess) {
 720         VLOG(1) << "Initializing NSS without a persistent database.";
 721         status = NSS_NoDB_Init(NULL);
 722         if (status != SECSuccess) {
 723           CrashOnNSSInitFailure();
 724           return;
 725         }
 726       }
 727
 728       PK11_SetPasswordFunc(PKCS11PasswordFunc);
 729
 730       // If we haven't initialized the password for the NSS databases,
 731       // initialize an empty-string password so that we don't need to
 732       // log in.
 733       PK11SlotInfo* slot = PK11_GetInternalKeySlot();
 734       if (slot) {
 735         // PK11_InitPin may write to the keyDB, but no other thread can use NSS
 736         // yet, so we don't need to lock.
 737         if (PK11_NeedUserInit(slot))
 738           PK11_InitPin(slot, NULL, NULL);
 739         PK11_FreeSlot(slot);
 740       }
 741
 742       root_ = InitDefaultRootCerts();
 743 #endif  // defined(USE_NSS)
 744     }
 745
 746     // Disable MD5 certificate signatures. (They are disabled by default in
 747     // NSS 3.14.)
 748     NSS_SetAlgorithmPolicy(SEC_OID_MD5, 0, NSS_USE_ALG_IN_CERT_SIGNATURE);
 749     NSS_SetAlgorithmPolicy(SEC_OID_PKCS1_MD5_WITH_RSA_ENCRYPTION,
 750                            0, NSS_USE_ALG_IN_CERT_SIGNATURE);
 751
 752     // The UMA bit is conditionally set for this histogram in
 753     // components/startup_metric_utils.cc .
 754     LOCAL_HISTOGRAM_CUSTOM_TIMES("Startup.SlowStartupNSSInit",
 755                                  base::TimeTicks::Now() - start_time,
 756                                  base::TimeDelta::FromMilliseconds(10),
 757                                  base::TimeDelta::FromHours(1),
 758                                  50);
 759   }
 760
 761   // NOTE(willchan): We don't actually execute this code since we leak NSS to
 762   // prevent non-joinable threads from using NSS after it's already been shut
 763   // down.
 764   ~NSSInitSingleton() {
 765 #if defined(OS_CHROMEOS)
 766     STLDeleteValues(&chromeos_user_map_);
 767 #endif
 768     tpm_slot_.reset();
 769     if (root_) {
 770       SECMOD_UnloadUserModule(root_);
 771       SECMOD_DestroyModule(root_);
 772       root_ = NULL;
 773     }
 774     if (chaps_module_) {
 775       SECMOD_UnloadUserModule(chaps_module_);
 776       SECMOD_DestroyModule(chaps_module_);
 777       chaps_module_ = NULL;
 778     }
 779
 780     SECStatus status = NSS_Shutdown();
 781     if (status != SECSuccess) {
 782       // We VLOG(1) because this failure is relatively harmless (leaking, but
 783       // we're shutting down anyway).
 784       VLOG(1) << "NSS_Shutdown failed; see http://crbug.com/4609";
 785     }
 786   }
 787
 788 #if defined(USE_NSS) || defined(OS_IOS)
 789   // Load nss's built-in root certs.
 790   SECMODModule* InitDefaultRootCerts() {
 791     SECMODModule* root = LoadModule("Root Certs", "libnssckbi.so", NULL);
 792     if (root)
 793       return root;
 794
 795     // Aw, snap.  Can't find/load root cert shared library.
 796     // This will make it hard to talk to anybody via https.
 797     // TODO(mattm): Re-add the NOTREACHED here when crbug.com/310972 is fixed.
 798     return NULL;
 799   }
 800
 801   // Load the given module for this NSS session.
 802   static SECMODModule* LoadModule(const char* name,
 803                                   const char* library_path,
 804                                   const char* params) {
 805     std::string modparams = base::StringPrintf(
 806         "name=\"%s\" library=\"%s\" %s",
 807         name, library_path, params ? params : "");
 808
 809     // Shouldn't need to const_cast here, but SECMOD doesn't properly
 810     // declare input string arguments as const.  Bug
 811     // https://bugzilla.mozilla.org/show_bug.cgi?id=642546 was filed
 812     // on NSS codebase to address this.
 813     SECMODModule* module = SECMOD_LoadUserModule(
 814         const_cast<char*>(modparams.c_str()), NULL, PR_FALSE);
 815     if (!module) {
 816       LOG(ERROR) << "Error loading " << name << " module into NSS: "
 817                  << GetNSSErrorMessage();
 818       return NULL;
 819     }
 820     if (!module->loaded) {
 821       LOG(ERROR) << "After loading " << name << ", loaded==false: "
 822                  << GetNSSErrorMessage();
 823       SECMOD_DestroyModule(module);
 824       return NULL;
 825     }
 826     return module;
 827   }
 828 #endif
 829
 830   static void DisableAESNIIfNeeded() {
 831     if (NSS_VersionCheck("3.15") && !NSS_VersionCheck("3.15.4")) {
 832       // Some versions of NSS have a bug that causes AVX instructions to be
 833       // used without testing whether XSAVE is enabled by the operating system.
 834       // In order to work around this, we disable AES-NI in NSS when we find
 835       // that |has_avx()| is false (which includes the XSAVE test). See
 836       // https://bugzilla.mozilla.org/show_bug.cgi?id=940794
 837       base::CPU cpu;
 838
 839       if (cpu.has_avx_hardware() && !cpu.has_avx()) {
 840         base::Environment::Create()->SetVar("NSS_DISABLE_HW_AES", "1");
 841       }
 842     }
 843   }
 844
 845   // If this is set to true NSS is forced to be initialized without a DB.
 846   static bool force_nodb_init_;
 847
 848   bool tpm_token_enabled_for_nss_;
 849   bool initializing_tpm_token_;
 850   typedef std::vector<base::Closure> TPMReadyCallbackList;
 851   TPMReadyCallbackList tpm_ready_callback_list_;
 852   SECMODModule* chaps_module_;
 853   crypto::ScopedPK11Slot tpm_slot_;
 854   SECMODModule* root_;
 855 #if defined(OS_CHROMEOS)
 856   typedef std::map<std::string, ChromeOSUserData*> ChromeOSUserMap;
 857   ChromeOSUserMap chromeos_user_map_;
 858   ScopedPK11Slot test_system_slot_;
 859 #endif
 860 #if defined(USE_NSS)
 861   // TODO(davidben): When https://bugzilla.mozilla.org/show_bug.cgi?id=564011
 862   // is fixed, we will no longer need the lock.
 863   base::Lock write_lock_;
 864 #endif  // defined(USE_NSS)
 865
 866   base::ThreadChecker thread_checker_;
 867 };
 868
 869 // static
 870 bool NSSInitSingleton::force_nodb_init_ = false;
 871
 872 base::LazyInstance<NSSInitSingleton>::Leaky
 873     g_nss_singleton = LAZY_INSTANCE_INITIALIZER;
 874 }  // namespace
 875
 876 #if defined(USE_NSS)
 877 ScopedPK11Slot OpenSoftwareNSSDB(const base::FilePath& path,
 878                                  const std::string& description) {
 879   const std::string modspec =
 880       base::StringPrintf("configDir='sql:%s' tokenDescription='%s'",
 881                          path.value().c_str(),
 882                          description.c_str());
 883   PK11SlotInfo* db_slot = SECMOD_OpenUserDB(modspec.c_str());
 884   if (db_slot) {
 885     if (PK11_NeedUserInit(db_slot))
 886       PK11_InitPin(db_slot, NULL, NULL);
 887   } else {
 888     LOG(ERROR) << "Error opening persistent database (" << modspec
 889                << "): " << GetNSSErrorMessage();
 890   }
 891   return ScopedPK11Slot(db_slot);
 892 }
 893
 894 void EarlySetupForNSSInit() {
 895   base::FilePath database_dir = GetInitialConfigDirectory();
 896   if (!database_dir.empty())
 897     UseLocalCacheOfNSSDatabaseIfNFS(database_dir);
 898 }
 899 #endif
 900
 901 void EnsureNSPRInit() {
 902   g_nspr_singleton.Get();
 903 }
 904
 905 void InitNSSSafely() {
 906   // We might fork, but we haven't loaded any security modules.
 907   DisableNSSForkCheck();
 908   // If we're sandboxed, we shouldn't be able to open user security modules,
 909   // but it's more correct to tell NSS to not even try.
 910   // Loading user security modules would have security implications.
 911   ForceNSSNoDBInit();
 912   // Initialize NSS.
 913   EnsureNSSInit();
 914 }
 915
 916 void EnsureNSSInit() {
 917   // Initializing SSL causes us to do blocking IO.
 918   // Temporarily allow it until we fix
 919   //   http://code.google.com/p/chromium/issues/detail?id=59847
 920   base::ThreadRestrictions::ScopedAllowIO allow_io;
 921   g_nss_singleton.Get();
 922 }
 923
 924 void ForceNSSNoDBInit() {
 925   NSSInitSingleton::ForceNoDBInit();
 926 }
 927
 928 void DisableNSSForkCheck() {
 929   scoped_ptr<base::Environment> env(base::Environment::Create());
 930   env->SetVar("NSS_STRICT_NOFORK", "DISABLED");
 931 }
 932
 933 void LoadNSSLibraries() {
 934   // Some NSS libraries are linked dynamically so load them here.
 935 #if defined(USE_NSS)
 936   // Try to search for multiple directories to load the libraries.
 937   std::vector<base::FilePath> paths;
 938
 939   // Use relative path to Search PATH for the library files.
 940   paths.push_back(base::FilePath());
 941
 942   // For Debian derivatives NSS libraries are located here.
 943   paths.push_back(base::FilePath("/usr/lib/nss"));
 944
 945   // Ubuntu 11.10 (Oneiric) and Debian Wheezy place the libraries here.
 946 #if defined(ARCH_CPU_X86_64)
 947   paths.push_back(base::FilePath("/usr/lib/x86_64-linux-gnu/nss"));
 948 #elif defined(ARCH_CPU_X86)
 949   paths.push_back(base::FilePath("/usr/lib/i386-linux-gnu/nss"));
 950 #elif defined(ARCH_CPU_ARMEL)
 951 #if defined(__ARM_PCS_VFP)
 952   paths.push_back(base::FilePath("/usr/lib/arm-linux-gnueabihf/nss"));
 953 #else
 954   paths.push_back(base::FilePath("/usr/lib/arm-linux-gnueabi/nss"));
 955 #endif  // defined(__ARM_PCS_VFP)
 956 #elif defined(ARCH_CPU_MIPSEL)
 957   paths.push_back(base::FilePath("/usr/lib/mipsel-linux-gnu/nss"));
 958 #endif  // defined(ARCH_CPU_X86_64)
 959
 960   // A list of library files to load.
 961   std::vector<std::string> libs;
 962   libs.push_back("libsoftokn3.so");
 963   libs.push_back("libfreebl3.so");
 964
 965   // For each combination of library file and path, check for existence and
 966   // then load.
 967   size_t loaded = 0;
 968   for (size_t i = 0; i < libs.size(); ++i) {
 969     for (size_t j = 0; j < paths.size(); ++j) {
 970       base::FilePath path = paths[j].Append(libs[i]);
 971       base::NativeLibrary lib = base::LoadNativeLibrary(path, NULL);
 972       if (lib) {
 973         ++loaded;
 974         break;
 975       }
 976     }
 977   }
 978
 979   if (loaded == libs.size()) {
 980     VLOG(3) << "NSS libraries loaded.";
 981   } else {
 982     LOG(ERROR) << "Failed to load NSS libraries.";
 983   }
 984 #endif  // defined(USE_NSS)
 985 }
 986
 987 bool CheckNSSVersion(const char* version) {
 988   return !!NSS_VersionCheck(version);
 989 }
 990
 991 #if defined(USE_NSS)
 992 base::Lock* GetNSSWriteLock() {
 993   return g_nss_singleton.Get().write_lock();
 994 }
 995
 996 AutoNSSWriteLock::AutoNSSWriteLock() : lock_(GetNSSWriteLock()) {
 997   // May be NULL if the lock is not needed in our version of NSS.
 998   if (lock_)
 999     lock_->Acquire();
1000 }
1001
1002 AutoNSSWriteLock::~AutoNSSWriteLock() {
1003   if (lock_) {
1004     lock_->AssertAcquired();
1005     lock_->Release();
1006   }
1007 }
1008
1009 AutoSECMODListReadLock::AutoSECMODListReadLock()
1010       : lock_(SECMOD_GetDefaultModuleListLock()) {
1011     SECMOD_GetReadLock(lock_);
1012   }
1013
1014 AutoSECMODListReadLock::~AutoSECMODListReadLock() {
1015   SECMOD_ReleaseReadLock(lock_);
1016 }
1017 #endif  // defined(USE_NSS)
1018
1019 #if defined(OS_CHROMEOS)
1020 ScopedPK11Slot GetSystemNSSKeySlot(
1021     const base::Callback<void(ScopedPK11Slot)>& callback) {
1022   return g_nss_singleton.Get().GetSystemNSSKeySlot(callback);
1023 }
1024
1025 void SetSystemKeySlotForTesting(ScopedPK11Slot slot) {
1026   g_nss_singleton.Get().SetSystemKeySlotForTesting(slot.Pass());
1027 }
1028
1029 void EnableTPMTokenForNSS() {
1030   g_nss_singleton.Get().EnableTPMTokenForNSS();
1031 }
1032
1033 bool IsTPMTokenEnabledForNSS() {
1034   return g_nss_singleton.Get().IsTPMTokenEnabledForNSS();
1035 }
1036
1037 bool IsTPMTokenReady(const base::Closure& callback) {
1038   return g_nss_singleton.Get().IsTPMTokenReady(callback);
1039 }
1040
1041 void InitializeTPMTokenAndSystemSlot(
1042     int token_slot_id,
1043     const base::Callback<void(bool)>& callback) {
1044   g_nss_singleton.Get().InitializeTPMTokenAndSystemSlot(token_slot_id,
1045                                                         callback);
1046 }
1047
1048 bool InitializeNSSForChromeOSUser(
1049     const std::string& email,
1050     const std::string& username_hash,
1051     const base::FilePath& path) {
1052   return g_nss_singleton.Get().InitializeNSSForChromeOSUser(
1053       email, username_hash, path);
1054 }
1055
1056 bool ShouldInitializeTPMForChromeOSUser(const std::string& username_hash) {
1057   return g_nss_singleton.Get().ShouldInitializeTPMForChromeOSUser(
1058       username_hash);
1059 }
1060
1061 void WillInitializeTPMForChromeOSUser(const std::string& username_hash) {
1062   g_nss_singleton.Get().WillInitializeTPMForChromeOSUser(username_hash);
1063 }
1064
1065 void InitializeTPMForChromeOSUser(
1066     const std::string& username_hash,
1067     CK_SLOT_ID slot_id) {
1068   g_nss_singleton.Get().InitializeTPMForChromeOSUser(username_hash, slot_id);
1069 }
1070
1071 void InitializePrivateSoftwareSlotForChromeOSUser(
1072     const std::string& username_hash) {
1073   g_nss_singleton.Get().InitializePrivateSoftwareSlotForChromeOSUser(
1074       username_hash);
1075 }
1076
1077 ScopedPK11Slot GetPublicSlotForChromeOSUser(const std::string& username_hash) {
1078   return g_nss_singleton.Get().GetPublicSlotForChromeOSUser(username_hash);
1079 }
1080
1081 ScopedPK11Slot GetPrivateSlotForChromeOSUser(
1082     const std::string& username_hash,
1083     const base::Callback<void(ScopedPK11Slot)>& callback) {
1084   return g_nss_singleton.Get().GetPrivateSlotForChromeOSUser(username_hash,
1085                                                              callback);
1086 }
1087
1088 void CloseChromeOSUserForTesting(const std::string& username_hash) {
1089   g_nss_singleton.Get().CloseChromeOSUserForTesting(username_hash);
1090 }
1091 #endif  // defined(OS_CHROMEOS)
1092
1093 base::Time PRTimeToBaseTime(PRTime prtime) {
1094   return base::Time::FromInternalValue(
1095       prtime + base::Time::UnixEpoch().ToInternalValue());
1096 }
1097
1098 PRTime BaseTimeToPRTime(base::Time time) {
1099   return time.ToInternalValue() - base::Time::UnixEpoch().ToInternalValue();
1100 }
1101
1102 #if !defined(OS_CHROMEOS)
1103 PK11SlotInfo* GetPersistentNSSKeySlot() {
1104   return g_nss_singleton.Get().GetPersistentNSSKeySlot();
1105 }
1106 #endif
1107
1108 }  // namespace crypto