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 #if defined(OS_CHROMEOS)
  22 #include <dlfcn.h>
  23 #endif
  24
  25 #include <map>
  26 #include <vector>
  27
  28 #include "base/base_paths.h"
  29 #include "base/bind.h"
  30 #include "base/cpu.h"
  31 #include "base/debug/alias.h"
  32 #include "base/debug/stack_trace.h"
  33 #include "base/environment.h"
  34 #include "base/files/file_path.h"
  35 #include "base/files/file_util.h"
  36 #include "base/lazy_instance.h"
  37 #include "base/logging.h"
  38 #include "base/memory/scoped_ptr.h"
  39 #include "base/message_loop/message_loop.h"
  40 #include "base/native_library.h"
  41 #include "base/path_service.h"
  42 #include "base/stl_util.h"
  43 #include "base/strings/stringprintf.h"
  44 #include "base/threading/thread_checker.h"
  45 #include "base/threading/thread_restrictions.h"
  46 #include "base/threading/worker_pool.h"
  47 #include "build/build_config.h"
  48
  49 // USE_NSS_CERTS means NSS is used for certificates and platform integration.
  50 // This requires additional support to manage the platform certificate and key
  51 // stores.
  52 #if defined(USE_NSS_CERTS)
  53 #include "base/synchronization/lock.h"
  54 #include "crypto/nss_crypto_module_delegate.h"
  55 #endif  // defined(USE_NSS_CERTS)
  56
  57 namespace crypto {
  58
  59 namespace {
  60
  61 #if defined(OS_CHROMEOS)
  62 const char kUserNSSDatabaseName[] = "UserNSSDB";
  63
  64 // Constants for loading the Chrome OS TPM-backed PKCS #11 library.
  65 const char kChapsModuleName[] = "Chaps";
  66 const char kChapsPath[] = "libchaps.so";
  67
  68 // Fake certificate authority database used for testing.
  69 static const base::FilePath::CharType kReadOnlyCertDB[] =
  70     FILE_PATH_LITERAL("/etc/fake_root_ca/nssdb");
  71 #endif  // defined(OS_CHROMEOS)
  72
  73 std::string GetNSSErrorMessage() {
  74   std::string result;
  75   if (PR_GetErrorTextLength()) {
  76     scoped_ptr<char[]> error_text(new char[PR_GetErrorTextLength() + 1]);
  77     PRInt32 copied = PR_GetErrorText(error_text.get());
  78     result = std::string(error_text.get(), copied);
  79   } else {
  80     result = base::StringPrintf("NSS error code: %d", PR_GetError());
  81   }
  82   return result;
  83 }
  84
  85 #if defined(USE_NSS_CERTS)
  86 #if !defined(OS_CHROMEOS)
  87 base::FilePath GetDefaultConfigDirectory() {
  88   base::FilePath dir;
  89   PathService::Get(base::DIR_HOME, &dir);
  90   if (dir.empty()) {
  91     LOG(ERROR) << "Failed to get home directory.";
  92     return dir;
  93   }
  94   dir = dir.AppendASCII(".pki").AppendASCII("nssdb");
  95   if (!base::CreateDirectory(dir)) {
  96     LOG(ERROR) << "Failed to create " << dir.value() << " directory.";
  97     dir.clear();
  98   }
  99   DVLOG(2) << "DefaultConfigDirectory: " << dir.value();
 100   return dir;
 101 }
 102 #endif  // !defined(IS_CHROMEOS)
 103
 104 // On non-Chrome OS platforms, return the default config directory. On Chrome OS
 105 // test images, return a read-only directory with fake root CA certs (which are
 106 // used by the local Google Accounts server mock we use when testing our login
 107 // code). On Chrome OS non-test images (where the read-only directory doesn't
 108 // exist), return an empty path.
 109 base::FilePath GetInitialConfigDirectory() {
 110 #if defined(OS_CHROMEOS)
 111   base::FilePath database_dir = base::FilePath(kReadOnlyCertDB);
 112   if (!base::PathExists(database_dir))
 113     database_dir.clear();
 114   return database_dir;
 115 #else
 116   return GetDefaultConfigDirectory();
 117 #endif  // defined(OS_CHROMEOS)
 118 }
 119
 120 // This callback for NSS forwards all requests to a caller-specified
 121 // CryptoModuleBlockingPasswordDelegate object.
 122 char* PKCS11PasswordFunc(PK11SlotInfo* slot, PRBool retry, void* arg) {
 123   crypto::CryptoModuleBlockingPasswordDelegate* delegate =
 124       reinterpret_cast<crypto::CryptoModuleBlockingPasswordDelegate*>(arg);
 125   if (delegate) {
 126     bool cancelled = false;
 127     std::string password = delegate->RequestPassword(PK11_GetTokenName(slot),
 128                                                      retry != PR_FALSE,
 129                                                      &cancelled);
 130     if (cancelled)
 131       return NULL;
 132     char* result = PORT_Strdup(password.c_str());
 133     password.replace(0, password.size(), password.size(), 0);
 134     return result;
 135   }
 136   DLOG(ERROR) << "PK11 password requested with NULL arg";
 137   return NULL;
 138 }
 139
 140 // NSS creates a local cache of the sqlite database if it detects that the
 141 // filesystem the database is on is much slower than the local disk.  The
 142 // detection doesn't work with the latest versions of sqlite, such as 3.6.22
 143 // (NSS bug https://bugzilla.mozilla.org/show_bug.cgi?id=578561).  So we set
 144 // the NSS environment variable NSS_SDB_USE_CACHE to "yes" to override NSS's
 145 // detection when database_dir is on NFS.  See http://crbug.com/48585.
 146 //
 147 // TODO(wtc): port this function to other USE_NSS_CERTS platforms.  It is
 148 // defined only for OS_LINUX and OS_OPENBSD simply because the statfs structure
 149 // is OS-specific.
 150 //
 151 // Because this function sets an environment variable it must be run before we
 152 // go multi-threaded.
 153 void UseLocalCacheOfNSSDatabaseIfNFS(const base::FilePath& database_dir) {
 154   bool db_on_nfs = false;
 155 #if defined(OS_LINUX)
 156   base::FileSystemType fs_type = base::FILE_SYSTEM_UNKNOWN;
 157   if (base::GetFileSystemType(database_dir, &fs_type))
 158     db_on_nfs = (fs_type == base::FILE_SYSTEM_NFS);
 159 #elif defined(OS_OPENBSD)
 160   struct statfs buf;
 161   if (statfs(database_dir.value().c_str(), &buf) == 0)
 162     db_on_nfs = (strcmp(buf.f_fstypename, MOUNT_NFS) == 0);
 163 #else
 164   NOTIMPLEMENTED();
 165 #endif
 166
 167   if (db_on_nfs) {
 168     scoped_ptr<base::Environment> env(base::Environment::Create());
 169     static const char kUseCacheEnvVar[] = "NSS_SDB_USE_CACHE";
 170     if (!env->HasVar(kUseCacheEnvVar))
 171       env->SetVar(kUseCacheEnvVar, "yes");
 172   }
 173 }
 174
 175 #endif  // defined(USE_NSS_CERTS)
 176
 177 // A singleton to initialize/deinitialize NSPR.
 178 // Separate from the NSS singleton because we initialize NSPR on the UI thread.
 179 // Now that we're leaking the singleton, we could merge back with the NSS
 180 // singleton.
 181 class NSPRInitSingleton {
 182  private:
 183   friend struct base::DefaultLazyInstanceTraits<NSPRInitSingleton>;
 184
 185   NSPRInitSingleton() {
 186     PR_Init(PR_USER_THREAD, PR_PRIORITY_NORMAL, 0);
 187   }
 188
 189   // NOTE(willchan): We don't actually execute this code since we leak NSS to
 190   // prevent non-joinable threads from using NSS after it's already been shut
 191   // down.
 192   ~NSPRInitSingleton() {
 193     PL_ArenaFinish();
 194     PRStatus prstatus = PR_Cleanup();
 195     if (prstatus != PR_SUCCESS)
 196       LOG(ERROR) << "PR_Cleanup failed; was NSPR initialized on wrong thread?";
 197   }
 198 };
 199
 200 base::LazyInstance<NSPRInitSingleton>::Leaky
 201     g_nspr_singleton = LAZY_INSTANCE_INITIALIZER;
 202
 203 // Force a crash with error info on NSS_NoDB_Init failure.
 204 void CrashOnNSSInitFailure() {
 205   int nss_error = PR_GetError();
 206   int os_error = PR_GetOSError();
 207   base::debug::Alias(&nss_error);
 208   base::debug::Alias(&os_error);
 209   LOG(ERROR) << "Error initializing NSS without a persistent database: "
 210              << GetNSSErrorMessage();
 211   LOG(FATAL) << "nss_error=" << nss_error << ", os_error=" << os_error;
 212 }
 213
 214 #if defined(OS_CHROMEOS)
 215 class ChromeOSUserData {
 216  public:
 217   explicit ChromeOSUserData(ScopedPK11Slot public_slot)
 218       : public_slot_(public_slot.Pass()),
 219         private_slot_initialization_started_(false) {}
 220   ~ChromeOSUserData() {
 221     if (public_slot_) {
 222       SECStatus status = SECMOD_CloseUserDB(public_slot_.get());
 223       if (status != SECSuccess)
 224         PLOG(ERROR) << "SECMOD_CloseUserDB failed: " << PORT_GetError();
 225     }
 226   }
 227
 228   ScopedPK11Slot GetPublicSlot() {
 229     return ScopedPK11Slot(
 230         public_slot_ ? PK11_ReferenceSlot(public_slot_.get()) : NULL);
 231   }
 232
 233   ScopedPK11Slot GetPrivateSlot(
 234       const base::Callback<void(ScopedPK11Slot)>& callback) {
 235     if (private_slot_)
 236       return ScopedPK11Slot(PK11_ReferenceSlot(private_slot_.get()));
 237     if (!callback.is_null())
 238       tpm_ready_callback_list_.push_back(callback);
 239     return ScopedPK11Slot();
 240   }
 241
 242   void SetPrivateSlot(ScopedPK11Slot private_slot) {
 243     DCHECK(!private_slot_);
 244     private_slot_ = private_slot.Pass();
 245
 246     SlotReadyCallbackList callback_list;
 247     callback_list.swap(tpm_ready_callback_list_);
 248     for (SlotReadyCallbackList::iterator i = callback_list.begin();
 249          i != callback_list.end();
 250          ++i) {
 251       (*i).Run(ScopedPK11Slot(PK11_ReferenceSlot(private_slot_.get())));
 252     }
 253   }
 254
 255   bool private_slot_initialization_started() const {
 256       return private_slot_initialization_started_;
 257   }
 258
 259   void set_private_slot_initialization_started() {
 260       private_slot_initialization_started_ = true;
 261   }
 262
 263  private:
 264   ScopedPK11Slot public_slot_;
 265   ScopedPK11Slot private_slot_;
 266
 267   bool private_slot_initialization_started_;
 268
 269   typedef std::vector<base::Callback<void(ScopedPK11Slot)> >
 270       SlotReadyCallbackList;
 271   SlotReadyCallbackList tpm_ready_callback_list_;
 272 };
 273
 274 class ScopedChapsLoadFixup {
 275   public:
 276     ScopedChapsLoadFixup();
 277     ~ScopedChapsLoadFixup();
 278
 279   private:
 280 #if defined(COMPONENT_BUILD)
 281     void *chaps_handle_;
 282 #endif
 283 };
 284
 285 #if defined(COMPONENT_BUILD)
 286
 287 ScopedChapsLoadFixup::ScopedChapsLoadFixup() {
 288   // HACK: libchaps links the system protobuf and there are symbol conflicts
 289   // with the bundled copy. Load chaps with RTLD_DEEPBIND to workaround.
 290   chaps_handle_ = dlopen(kChapsPath, RTLD_LOCAL | RTLD_NOW | RTLD_DEEPBIND);
 291 }
 292
 293 ScopedChapsLoadFixup::~ScopedChapsLoadFixup() {
 294   // LoadModule() will have taken a 2nd reference.
 295   if (chaps_handle_)
 296     dlclose(chaps_handle_);
 297 }
 298
 299 #else
 300
 301 ScopedChapsLoadFixup::ScopedChapsLoadFixup() {}
 302 ScopedChapsLoadFixup::~ScopedChapsLoadFixup() {}
 303
 304 #endif  // defined(COMPONENT_BUILD)
 305 #endif  // defined(OS_CHROMEOS)
 306
 307 class NSSInitSingleton {
 308  public:
 309 #if defined(OS_CHROMEOS)
 310   // Used with PostTaskAndReply to pass handles to worker thread and back.
 311   struct TPMModuleAndSlot {
 312     explicit TPMModuleAndSlot(SECMODModule* init_chaps_module)
 313         : chaps_module(init_chaps_module) {}
 314     SECMODModule* chaps_module;
 315     crypto::ScopedPK11Slot tpm_slot;
 316   };
 317
 318   ScopedPK11Slot OpenPersistentNSSDBForPath(const std::string& db_name,
 319                                             const base::FilePath& path) {
 320     DCHECK(thread_checker_.CalledOnValidThread());
 321     // NSS is allowed to do IO on the current thread since dispatching
 322     // to a dedicated thread would still have the affect of blocking
 323     // the current thread, due to NSS's internal locking requirements
 324     base::ThreadRestrictions::ScopedAllowIO allow_io;
 325
 326     base::FilePath nssdb_path = path.AppendASCII(".pki").AppendASCII("nssdb");
 327     if (!base::CreateDirectory(nssdb_path)) {
 328       LOG(ERROR) << "Failed to create " << nssdb_path.value() << " directory.";
 329       return ScopedPK11Slot();
 330     }
 331     return OpenSoftwareNSSDB(nssdb_path, db_name);
 332   }
 333
 334   void EnableTPMTokenForNSS() {
 335     DCHECK(thread_checker_.CalledOnValidThread());
 336
 337     // If this gets set, then we'll use the TPM for certs with
 338     // private keys, otherwise we'll fall back to the software
 339     // implementation.
 340     tpm_token_enabled_for_nss_ = true;
 341   }
 342
 343   bool IsTPMTokenEnabledForNSS() {
 344     DCHECK(thread_checker_.CalledOnValidThread());
 345     return tpm_token_enabled_for_nss_;
 346   }
 347
 348   void InitializeTPMTokenAndSystemSlot(
 349       int system_slot_id,
 350       const base::Callback<void(bool)>& callback) {
 351     DCHECK(thread_checker_.CalledOnValidThread());
 352     // Should not be called while there is already an initialization in
 353     // progress.
 354     DCHECK(!initializing_tpm_token_);
 355     // If EnableTPMTokenForNSS hasn't been called, return false.
 356     if (!tpm_token_enabled_for_nss_) {
 357       base::MessageLoop::current()->PostTask(FROM_HERE,
 358                                              base::Bind(callback, false));
 359       return;
 360     }
 361
 362     // If everything is already initialized, then return true.
 363     // Note that only |tpm_slot_| is checked, since |chaps_module_| could be
 364     // NULL in tests while |tpm_slot_| has been set to the test DB.
 365     if (tpm_slot_) {
 366       base::MessageLoop::current()->PostTask(FROM_HERE,
 367                                              base::Bind(callback, true));
 368       return;
 369     }
 370
 371     // Note that a reference is not taken to chaps_module_. This is safe since
 372     // NSSInitSingleton is Leaky, so the reference it holds is never released.
 373     scoped_ptr<TPMModuleAndSlot> tpm_args(new TPMModuleAndSlot(chaps_module_));
 374     TPMModuleAndSlot* tpm_args_ptr = tpm_args.get();
 375     if (base::WorkerPool::PostTaskAndReply(
 376             FROM_HERE,
 377             base::Bind(&NSSInitSingleton::InitializeTPMTokenOnWorkerThread,
 378                        system_slot_id,
 379                        tpm_args_ptr),
 380             base::Bind(&NSSInitSingleton::OnInitializedTPMTokenAndSystemSlot,
 381                        base::Unretained(this),  // NSSInitSingleton is leaky
 382                        callback,
 383                        base::Passed(&tpm_args)),
 384             true /* task_is_slow */
 385             )) {
 386       initializing_tpm_token_ = true;
 387     } else {
 388       base::MessageLoop::current()->PostTask(FROM_HERE,
 389                                              base::Bind(callback, false));
 390     }
 391   }
 392
 393   static void InitializeTPMTokenOnWorkerThread(CK_SLOT_ID token_slot_id,
 394                                                TPMModuleAndSlot* tpm_args) {
 395     // This tries to load the Chaps module so NSS can talk to the hardware
 396     // TPM.
 397     if (!tpm_args->chaps_module) {
 398       ScopedChapsLoadFixup chaps_loader;
 399
 400       DVLOG(3) << "Loading chaps...";
 401       tpm_args->chaps_module = LoadModule(
 402           kChapsModuleName,
 403           kChapsPath,
 404           // For more details on these parameters, see:
 405           // https://developer.mozilla.org/en/PKCS11_Module_Specs
 406           // slotFlags=[PublicCerts] -- Certificates and public keys can be
 407           //   read from this slot without requiring a call to C_Login.
 408           // askpw=only -- Only authenticate to the token when necessary.
 409           "NSS=\"slotParams=(0={slotFlags=[PublicCerts] askpw=only})\"");
 410     }
 411     if (tpm_args->chaps_module) {
 412       tpm_args->tpm_slot =
 413           GetTPMSlotForIdOnWorkerThread(tpm_args->chaps_module, token_slot_id);
 414     }
 415   }
 416
 417   void OnInitializedTPMTokenAndSystemSlot(
 418       const base::Callback<void(bool)>& callback,
 419       scoped_ptr<TPMModuleAndSlot> tpm_args) {
 420     DCHECK(thread_checker_.CalledOnValidThread());
 421     DVLOG(2) << "Loaded chaps: " << !!tpm_args->chaps_module
 422              << ", got tpm slot: " << !!tpm_args->tpm_slot;
 423
 424     chaps_module_ = tpm_args->chaps_module;
 425     tpm_slot_ = tpm_args->tpm_slot.Pass();
 426     if (!chaps_module_ && test_system_slot_) {
 427       // chromeos_unittests try to test the TPM initialization process. If we
 428       // have a test DB open, pretend that it is the TPM slot.
 429       tpm_slot_.reset(PK11_ReferenceSlot(test_system_slot_.get()));
 430     }
 431     initializing_tpm_token_ = false;
 432
 433     if (tpm_slot_)
 434       RunAndClearTPMReadyCallbackList();
 435
 436     callback.Run(!!tpm_slot_);
 437   }
 438
 439   void RunAndClearTPMReadyCallbackList() {
 440     TPMReadyCallbackList callback_list;
 441     callback_list.swap(tpm_ready_callback_list_);
 442     for (TPMReadyCallbackList::iterator i = callback_list.begin();
 443          i != callback_list.end();
 444          ++i) {
 445       i->Run();
 446     }
 447   }
 448
 449   bool IsTPMTokenReady(const base::Closure& callback) {
 450     if (!callback.is_null()) {
 451       // Cannot DCHECK in the general case yet, but since the callback is
 452       // a new addition to the API, DCHECK to make sure at least the new uses
 453       // don't regress.
 454       DCHECK(thread_checker_.CalledOnValidThread());
 455     } else if (!thread_checker_.CalledOnValidThread()) {
 456       // TODO(mattm): Change to DCHECK when callers have been fixed.
 457       DVLOG(1) << "Called on wrong thread.\n"
 458                << base::debug::StackTrace().ToString();
 459     }
 460
 461     if (tpm_slot_)
 462       return true;
 463
 464     if (!callback.is_null())
 465       tpm_ready_callback_list_.push_back(callback);
 466
 467     return false;
 468   }
 469
 470   // Note that CK_SLOT_ID is an unsigned long, but cryptohome gives us the slot
 471   // id as an int. This should be safe since this is only used with chaps, which
 472   // we also control.
 473   static crypto::ScopedPK11Slot GetTPMSlotForIdOnWorkerThread(
 474       SECMODModule* chaps_module,
 475       CK_SLOT_ID slot_id) {
 476     DCHECK(chaps_module);
 477
 478     DVLOG(3) << "Poking chaps module.";
 479     SECStatus rv = SECMOD_UpdateSlotList(chaps_module);
 480     if (rv != SECSuccess)
 481       PLOG(ERROR) << "SECMOD_UpdateSlotList failed: " << PORT_GetError();
 482
 483     PK11SlotInfo* slot = SECMOD_LookupSlot(chaps_module->moduleID, slot_id);
 484     if (!slot)
 485       LOG(ERROR) << "TPM slot " << slot_id << " not found.";
 486     return crypto::ScopedPK11Slot(slot);
 487   }
 488
 489   bool InitializeNSSForChromeOSUser(const std::string& username_hash,
 490                                     const base::FilePath& path) {
 491     DCHECK(thread_checker_.CalledOnValidThread());
 492     if (chromeos_user_map_.find(username_hash) != chromeos_user_map_.end()) {
 493       // This user already exists in our mapping.
 494       DVLOG(2) << username_hash << " already initialized.";
 495       return false;
 496     }
 497
 498     DVLOG(2) << "Opening NSS DB " << path.value();
 499     std::string db_name = base::StringPrintf(
 500         "%s %s", kUserNSSDatabaseName, username_hash.c_str());
 501     ScopedPK11Slot public_slot(OpenPersistentNSSDBForPath(db_name, path));
 502     chromeos_user_map_[username_hash] =
 503         new ChromeOSUserData(public_slot.Pass());
 504     return true;
 505   }
 506
 507   bool ShouldInitializeTPMForChromeOSUser(const std::string& username_hash) {
 508     DCHECK(thread_checker_.CalledOnValidThread());
 509     DCHECK(chromeos_user_map_.find(username_hash) != chromeos_user_map_.end());
 510
 511     return !chromeos_user_map_[username_hash]
 512                 ->private_slot_initialization_started();
 513   }
 514
 515   void WillInitializeTPMForChromeOSUser(const std::string& username_hash) {
 516     DCHECK(thread_checker_.CalledOnValidThread());
 517     DCHECK(chromeos_user_map_.find(username_hash) != chromeos_user_map_.end());
 518
 519     chromeos_user_map_[username_hash]
 520         ->set_private_slot_initialization_started();
 521   }
 522
 523   void InitializeTPMForChromeOSUser(const std::string& username_hash,
 524                                     CK_SLOT_ID slot_id) {
 525     DCHECK(thread_checker_.CalledOnValidThread());
 526     DCHECK(chromeos_user_map_.find(username_hash) != chromeos_user_map_.end());
 527     DCHECK(chromeos_user_map_[username_hash]->
 528                private_slot_initialization_started());
 529
 530     if (!chaps_module_)
 531       return;
 532
 533     // Note that a reference is not taken to chaps_module_. This is safe since
 534     // NSSInitSingleton is Leaky, so the reference it holds is never released.
 535     scoped_ptr<TPMModuleAndSlot> tpm_args(new TPMModuleAndSlot(chaps_module_));
 536     TPMModuleAndSlot* tpm_args_ptr = tpm_args.get();
 537     base::WorkerPool::PostTaskAndReply(
 538         FROM_HERE,
 539         base::Bind(&NSSInitSingleton::InitializeTPMTokenOnWorkerThread,
 540                    slot_id,
 541                    tpm_args_ptr),
 542         base::Bind(&NSSInitSingleton::OnInitializedTPMForChromeOSUser,
 543                    base::Unretained(this),  // NSSInitSingleton is leaky
 544                    username_hash,
 545                    base::Passed(&tpm_args)),
 546         true /* task_is_slow */
 547         );
 548   }
 549
 550   void OnInitializedTPMForChromeOSUser(const std::string& username_hash,
 551                                        scoped_ptr<TPMModuleAndSlot> tpm_args) {
 552     DCHECK(thread_checker_.CalledOnValidThread());
 553     DVLOG(2) << "Got tpm slot for " << username_hash << " "
 554              << !!tpm_args->tpm_slot;
 555     chromeos_user_map_[username_hash]->SetPrivateSlot(
 556         tpm_args->tpm_slot.Pass());
 557   }
 558
 559   void InitializePrivateSoftwareSlotForChromeOSUser(
 560       const std::string& username_hash) {
 561     DCHECK(thread_checker_.CalledOnValidThread());
 562     VLOG(1) << "using software private slot for " << username_hash;
 563     DCHECK(chromeos_user_map_.find(username_hash) != chromeos_user_map_.end());
 564     DCHECK(chromeos_user_map_[username_hash]->
 565                private_slot_initialization_started());
 566
 567     chromeos_user_map_[username_hash]->SetPrivateSlot(
 568         chromeos_user_map_[username_hash]->GetPublicSlot());
 569   }
 570
 571   ScopedPK11Slot GetPublicSlotForChromeOSUser(
 572       const std::string& username_hash) {
 573     DCHECK(thread_checker_.CalledOnValidThread());
 574
 575     if (username_hash.empty()) {
 576       DVLOG(2) << "empty username_hash";
 577       return ScopedPK11Slot();
 578     }
 579
 580     if (chromeos_user_map_.find(username_hash) == chromeos_user_map_.end()) {
 581       LOG(ERROR) << username_hash << " not initialized.";
 582       return ScopedPK11Slot();
 583     }
 584     return chromeos_user_map_[username_hash]->GetPublicSlot();
 585   }
 586
 587   ScopedPK11Slot GetPrivateSlotForChromeOSUser(
 588       const std::string& username_hash,
 589       const base::Callback<void(ScopedPK11Slot)>& callback) {
 590     DCHECK(thread_checker_.CalledOnValidThread());
 591
 592     if (username_hash.empty()) {
 593       DVLOG(2) << "empty username_hash";
 594       if (!callback.is_null()) {
 595         base::MessageLoop::current()->PostTask(
 596             FROM_HERE, base::Bind(callback, base::Passed(ScopedPK11Slot())));
 597       }
 598       return ScopedPK11Slot();
 599     }
 600
 601     DCHECK(chromeos_user_map_.find(username_hash) != chromeos_user_map_.end());
 602
 603     return chromeos_user_map_[username_hash]->GetPrivateSlot(callback);
 604   }
 605
 606   void CloseChromeOSUserForTesting(const std::string& username_hash) {
 607     DCHECK(thread_checker_.CalledOnValidThread());
 608     ChromeOSUserMap::iterator i = chromeos_user_map_.find(username_hash);
 609     DCHECK(i != chromeos_user_map_.end());
 610     delete i->second;
 611     chromeos_user_map_.erase(i);
 612   }
 613
 614   void SetSystemKeySlotForTesting(ScopedPK11Slot slot) {
 615     // Ensure that a previous value of test_system_slot_ is not overwritten.
 616     // Unsetting, i.e. setting a NULL, however is allowed.
 617     DCHECK(!slot || !test_system_slot_);
 618     test_system_slot_ = slot.Pass();
 619     if (test_system_slot_) {
 620       tpm_slot_.reset(PK11_ReferenceSlot(test_system_slot_.get()));
 621       RunAndClearTPMReadyCallbackList();
 622     } else {
 623       tpm_slot_.reset();
 624     }
 625   }
 626 #endif  // defined(OS_CHROMEOS)
 627
 628 #if !defined(OS_CHROMEOS)
 629   PK11SlotInfo* GetPersistentNSSKeySlot() {
 630     // TODO(mattm): Change to DCHECK when callers have been fixed.
 631     if (!thread_checker_.CalledOnValidThread()) {
 632       DVLOG(1) << "Called on wrong thread.\n"
 633                << base::debug::StackTrace().ToString();
 634     }
 635
 636     return PK11_GetInternalKeySlot();
 637   }
 638 #endif
 639
 640 #if defined(OS_CHROMEOS)
 641   void GetSystemNSSKeySlotCallback(
 642       const base::Callback<void(ScopedPK11Slot)>& callback) {
 643     callback.Run(ScopedPK11Slot(PK11_ReferenceSlot(tpm_slot_.get())));
 644   }
 645
 646   ScopedPK11Slot GetSystemNSSKeySlot(
 647       const base::Callback<void(ScopedPK11Slot)>& callback) {
 648     DCHECK(thread_checker_.CalledOnValidThread());
 649     // TODO(mattm): chromeos::TPMTokenloader always calls
 650     // InitializeTPMTokenAndSystemSlot with slot 0.  If the system slot is
 651     // disabled, tpm_slot_ will be the first user's slot instead. Can that be
 652     // detected and return NULL instead?
 653
 654     base::Closure wrapped_callback;
 655     if (!callback.is_null()) {
 656       wrapped_callback =
 657           base::Bind(&NSSInitSingleton::GetSystemNSSKeySlotCallback,
 658                      base::Unretained(this) /* singleton is leaky */,
 659                      callback);
 660     }
 661     if (IsTPMTokenReady(wrapped_callback))
 662       return ScopedPK11Slot(PK11_ReferenceSlot(tpm_slot_.get()));
 663     return ScopedPK11Slot();
 664   }
 665 #endif
 666
 667 #if defined(USE_NSS_CERTS)
 668   base::Lock* write_lock() {
 669     return &write_lock_;
 670   }
 671 #endif  // defined(USE_NSS_CERTS)
 672
 673   // This method is used to force NSS to be initialized without a DB.
 674   // Call this method before NSSInitSingleton() is constructed.
 675   static void ForceNoDBInit() {
 676     force_nodb_init_ = true;
 677   }
 678
 679  private:
 680   friend struct base::DefaultLazyInstanceTraits<NSSInitSingleton>;
 681
 682   NSSInitSingleton()
 683       : tpm_token_enabled_for_nss_(false),
 684         initializing_tpm_token_(false),
 685         chaps_module_(NULL),
 686         root_(NULL) {
 687     // It's safe to construct on any thread, since LazyInstance will prevent any
 688     // other threads from accessing until the constructor is done.
 689     thread_checker_.DetachFromThread();
 690
 691     DisableAESNIIfNeeded();
 692
 693     EnsureNSPRInit();
 694
 695     // We *must* have NSS >= 3.14.3.
 696     static_assert(
 697         (NSS_VMAJOR == 3 && NSS_VMINOR == 14 && NSS_VPATCH >= 3) ||
 698         (NSS_VMAJOR == 3 && NSS_VMINOR > 14) ||
 699         (NSS_VMAJOR > 3),
 700         "nss version check failed");
 701     // Also check the run-time NSS version.
 702     // NSS_VersionCheck is a >= check, not strict equality.
 703     if (!NSS_VersionCheck("3.14.3")) {
 704       LOG(FATAL) << "NSS_VersionCheck(\"3.14.3\") failed. NSS >= 3.14.3 is "
 705                     "required. Please upgrade to the latest NSS, and if you "
 706                     "still get this error, contact your distribution "
 707                     "maintainer.";
 708     }
 709
 710     SECStatus status = SECFailure;
 711     bool nodb_init = force_nodb_init_;
 712
 713 #if !defined(USE_NSS_CERTS)
 714     // Use the system certificate store, so initialize NSS without database.
 715     nodb_init = true;
 716 #endif
 717
 718     if (nodb_init) {
 719       status = NSS_NoDB_Init(NULL);
 720       if (status != SECSuccess) {
 721         CrashOnNSSInitFailure();
 722         return;
 723       }
 724 #if defined(OS_IOS)
 725       root_ = InitDefaultRootCerts();
 726 #endif  // defined(OS_IOS)
 727     } else {
 728 #if defined(USE_NSS_CERTS)
 729       base::FilePath database_dir = GetInitialConfigDirectory();
 730       if (!database_dir.empty()) {
 731         // This duplicates the work which should have been done in
 732         // EarlySetupForNSSInit. However, this function is idempotent so
 733         // there's no harm done.
 734         UseLocalCacheOfNSSDatabaseIfNFS(database_dir);
 735
 736         // Initialize with a persistent database (likely, ~/.pki/nssdb).
 737         // Use "sql:" which can be shared by multiple processes safely.
 738         std::string nss_config_dir =
 739             base::StringPrintf("sql:%s", database_dir.value().c_str());
 740 #if defined(OS_CHROMEOS)
 741         status = NSS_Init(nss_config_dir.c_str());
 742 #else
 743         status = NSS_InitReadWrite(nss_config_dir.c_str());
 744 #endif
 745         if (status != SECSuccess) {
 746           LOG(ERROR) << "Error initializing NSS with a persistent "
 747                         "database (" << nss_config_dir
 748                      << "): " << GetNSSErrorMessage();
 749         }
 750       }
 751       if (status != SECSuccess) {
 752         VLOG(1) << "Initializing NSS without a persistent database.";
 753         status = NSS_NoDB_Init(NULL);
 754         if (status != SECSuccess) {
 755           CrashOnNSSInitFailure();
 756           return;
 757         }
 758       }
 759
 760       PK11_SetPasswordFunc(PKCS11PasswordFunc);
 761
 762       // If we haven't initialized the password for the NSS databases,
 763       // initialize an empty-string password so that we don't need to
 764       // log in.
 765       PK11SlotInfo* slot = PK11_GetInternalKeySlot();
 766       if (slot) {
 767         // PK11_InitPin may write to the keyDB, but no other thread can use NSS
 768         // yet, so we don't need to lock.
 769         if (PK11_NeedUserInit(slot))
 770           PK11_InitPin(slot, NULL, NULL);
 771         PK11_FreeSlot(slot);
 772       }
 773
 774       root_ = InitDefaultRootCerts();
 775 #endif  // defined(USE_NSS_CERTS)
 776     }
 777
 778     // Disable MD5 certificate signatures. (They are disabled by default in
 779     // NSS 3.14.)
 780     NSS_SetAlgorithmPolicy(SEC_OID_MD5, 0, NSS_USE_ALG_IN_CERT_SIGNATURE);
 781     NSS_SetAlgorithmPolicy(SEC_OID_PKCS1_MD5_WITH_RSA_ENCRYPTION,
 782                            0, NSS_USE_ALG_IN_CERT_SIGNATURE);
 783   }
 784
 785   // NOTE(willchan): We don't actually execute this code since we leak NSS to
 786   // prevent non-joinable threads from using NSS after it's already been shut
 787   // down.
 788   ~NSSInitSingleton() {
 789 #if defined(OS_CHROMEOS)
 790     STLDeleteValues(&chromeos_user_map_);
 791 #endif
 792     tpm_slot_.reset();
 793     if (root_) {
 794       SECMOD_UnloadUserModule(root_);
 795       SECMOD_DestroyModule(root_);
 796       root_ = NULL;
 797     }
 798     if (chaps_module_) {
 799       SECMOD_UnloadUserModule(chaps_module_);
 800       SECMOD_DestroyModule(chaps_module_);
 801       chaps_module_ = NULL;
 802     }
 803
 804     SECStatus status = NSS_Shutdown();
 805     if (status != SECSuccess) {
 806       // We VLOG(1) because this failure is relatively harmless (leaking, but
 807       // we're shutting down anyway).
 808       VLOG(1) << "NSS_Shutdown failed; see http://crbug.com/4609";
 809     }
 810   }
 811
 812 #if defined(USE_NSS_CERTS) || defined(OS_IOS)
 813   // Load nss's built-in root certs.
 814   SECMODModule* InitDefaultRootCerts() {
 815     SECMODModule* root = LoadModule("Root Certs", "libnssckbi.so", NULL);
 816     if (root)
 817       return root;
 818
 819     // Aw, snap.  Can't find/load root cert shared library.
 820     // This will make it hard to talk to anybody via https.
 821     // TODO(mattm): Re-add the NOTREACHED here when crbug.com/310972 is fixed.
 822     return NULL;
 823   }
 824
 825   // Load the given module for this NSS session.
 826   static SECMODModule* LoadModule(const char* name,
 827                                   const char* library_path,
 828                                   const char* params) {
 829     std::string modparams = base::StringPrintf(
 830         "name=\"%s\" library=\"%s\" %s",
 831         name, library_path, params ? params : "");
 832
 833     // Shouldn't need to const_cast here, but SECMOD doesn't properly
 834     // declare input string arguments as const.  Bug
 835     // https://bugzilla.mozilla.org/show_bug.cgi?id=642546 was filed
 836     // on NSS codebase to address this.
 837     SECMODModule* module = SECMOD_LoadUserModule(
 838         const_cast<char*>(modparams.c_str()), NULL, PR_FALSE);
 839     if (!module) {
 840       LOG(ERROR) << "Error loading " << name << " module into NSS: "
 841                  << GetNSSErrorMessage();
 842       return NULL;
 843     }
 844     if (!module->loaded) {
 845       LOG(ERROR) << "After loading " << name << ", loaded==false: "
 846                  << GetNSSErrorMessage();
 847       SECMOD_DestroyModule(module);
 848       return NULL;
 849     }
 850     return module;
 851   }
 852 #endif
 853
 854   static void DisableAESNIIfNeeded() {
 855     if (NSS_VersionCheck("3.15") && !NSS_VersionCheck("3.15.4")) {
 856       // Some versions of NSS have a bug that causes AVX instructions to be
 857       // used without testing whether XSAVE is enabled by the operating system.
 858       // In order to work around this, we disable AES-NI in NSS when we find
 859       // that |has_avx()| is false (which includes the XSAVE test). See
 860       // https://bugzilla.mozilla.org/show_bug.cgi?id=940794
 861       base::CPU cpu;
 862
 863       if (cpu.has_avx_hardware() && !cpu.has_avx()) {
 864         scoped_ptr<base::Environment> env(base::Environment::Create());
 865         env->SetVar("NSS_DISABLE_HW_AES", "1");
 866       }
 867     }
 868   }
 869
 870   // If this is set to true NSS is forced to be initialized without a DB.
 871   static bool force_nodb_init_;
 872
 873   bool tpm_token_enabled_for_nss_;
 874   bool initializing_tpm_token_;
 875   typedef std::vector<base::Closure> TPMReadyCallbackList;
 876   TPMReadyCallbackList tpm_ready_callback_list_;
 877   SECMODModule* chaps_module_;
 878   crypto::ScopedPK11Slot tpm_slot_;
 879   SECMODModule* root_;
 880 #if defined(OS_CHROMEOS)
 881   typedef std::map<std::string, ChromeOSUserData*> ChromeOSUserMap;
 882   ChromeOSUserMap chromeos_user_map_;
 883   ScopedPK11Slot test_system_slot_;
 884 #endif
 885 #if defined(USE_NSS_CERTS)
 886   // TODO(davidben): When https://bugzilla.mozilla.org/show_bug.cgi?id=564011
 887   // is fixed, we will no longer need the lock.
 888   base::Lock write_lock_;
 889 #endif  // defined(USE_NSS_CERTS)
 890
 891   base::ThreadChecker thread_checker_;
 892 };
 893
 894 // static
 895 bool NSSInitSingleton::force_nodb_init_ = false;
 896
 897 base::LazyInstance<NSSInitSingleton>::Leaky
 898     g_nss_singleton = LAZY_INSTANCE_INITIALIZER;
 899 }  // namespace
 900
 901 #if defined(USE_NSS_CERTS)
 902 ScopedPK11Slot OpenSoftwareNSSDB(const base::FilePath& path,
 903                                  const std::string& description) {
 904   const std::string modspec =
 905       base::StringPrintf("configDir='sql:%s' tokenDescription='%s'",
 906                          path.value().c_str(),
 907                          description.c_str());
 908   PK11SlotInfo* db_slot = SECMOD_OpenUserDB(modspec.c_str());
 909   if (db_slot) {
 910     if (PK11_NeedUserInit(db_slot))
 911       PK11_InitPin(db_slot, NULL, NULL);
 912   } else {
 913     LOG(ERROR) << "Error opening persistent database (" << modspec
 914                << "): " << GetNSSErrorMessage();
 915   }
 916   return ScopedPK11Slot(db_slot);
 917 }
 918
 919 void EarlySetupForNSSInit() {
 920   base::FilePath database_dir = GetInitialConfigDirectory();
 921   if (!database_dir.empty())
 922     UseLocalCacheOfNSSDatabaseIfNFS(database_dir);
 923 }
 924 #endif
 925
 926 void EnsureNSPRInit() {
 927   g_nspr_singleton.Get();
 928 }
 929
 930 void InitNSSSafely() {
 931   // We might fork, but we haven't loaded any security modules.
 932   DisableNSSForkCheck();
 933   // If we're sandboxed, we shouldn't be able to open user security modules,
 934   // but it's more correct to tell NSS to not even try.
 935   // Loading user security modules would have security implications.
 936   ForceNSSNoDBInit();
 937   // Initialize NSS.
 938   EnsureNSSInit();
 939 }
 940
 941 void EnsureNSSInit() {
 942   // Initializing SSL causes us to do blocking IO.
 943   // Temporarily allow it until we fix
 944   //   http://code.google.com/p/chromium/issues/detail?id=59847
 945   base::ThreadRestrictions::ScopedAllowIO allow_io;
 946   g_nss_singleton.Get();
 947 }
 948
 949 void ForceNSSNoDBInit() {
 950   NSSInitSingleton::ForceNoDBInit();
 951 }
 952
 953 void DisableNSSForkCheck() {
 954   scoped_ptr<base::Environment> env(base::Environment::Create());
 955   env->SetVar("NSS_STRICT_NOFORK", "DISABLED");
 956 }
 957
 958 void LoadNSSLibraries() {
 959   // Some NSS libraries are linked dynamically so load them here.
 960 #if defined(USE_NSS_CERTS)
 961   // Try to search for multiple directories to load the libraries.
 962   std::vector<base::FilePath> paths;
 963
 964   // Use relative path to Search PATH for the library files.
 965   paths.push_back(base::FilePath());
 966
 967   // For Debian derivatives NSS libraries are located here.
 968   paths.push_back(base::FilePath("/usr/lib/nss"));
 969
 970   // Ubuntu 11.10 (Oneiric) and Debian Wheezy place the libraries here.
 971 #if defined(ARCH_CPU_X86_64)
 972   paths.push_back(base::FilePath("/usr/lib/x86_64-linux-gnu/nss"));
 973 #elif defined(ARCH_CPU_X86)
 974   paths.push_back(base::FilePath("/usr/lib/i386-linux-gnu/nss"));
 975 #elif defined(ARCH_CPU_ARMEL)
 976 #if defined(__ARM_PCS_VFP)
 977   paths.push_back(base::FilePath("/usr/lib/arm-linux-gnueabihf/nss"));
 978 #else
 979   paths.push_back(base::FilePath("/usr/lib/arm-linux-gnueabi/nss"));
 980 #endif  // defined(__ARM_PCS_VFP)
 981 #elif defined(ARCH_CPU_MIPSEL)
 982   paths.push_back(base::FilePath("/usr/lib/mipsel-linux-gnu/nss"));
 983 #endif  // defined(ARCH_CPU_X86_64)
 984
 985   // A list of library files to load.
 986   std::vector<std::string> libs;
 987   libs.push_back("libsoftokn3.so");
 988   libs.push_back("libfreebl3.so");
 989
 990   // For each combination of library file and path, check for existence and
 991   // then load.
 992   size_t loaded = 0;
 993   for (size_t i = 0; i < libs.size(); ++i) {
 994     for (size_t j = 0; j < paths.size(); ++j) {
 995       base::FilePath path = paths[j].Append(libs[i]);
 996       base::NativeLibrary lib = base::LoadNativeLibrary(path, NULL);
 997       if (lib) {
 998         ++loaded;
 999         break;
1000       }
1001     }
1002   }
1003
1004   if (loaded == libs.size()) {
1005     VLOG(3) << "NSS libraries loaded.";
1006   } else {
1007     LOG(ERROR) << "Failed to load NSS libraries.";
1008   }
1009 #endif  // defined(USE_NSS_CERTS)
1010 }
1011
1012 bool CheckNSSVersion(const char* version) {
1013   return !!NSS_VersionCheck(version);
1014 }
1015
1016 #if defined(USE_NSS_CERTS)
1017 base::Lock* GetNSSWriteLock() {
1018   return g_nss_singleton.Get().write_lock();
1019 }
1020
1021 AutoNSSWriteLock::AutoNSSWriteLock() : lock_(GetNSSWriteLock()) {
1022   // May be NULL if the lock is not needed in our version of NSS.
1023   if (lock_)
1024     lock_->Acquire();
1025 }
1026
1027 AutoNSSWriteLock::~AutoNSSWriteLock() {
1028   if (lock_) {
1029     lock_->AssertAcquired();
1030     lock_->Release();
1031   }
1032 }
1033
1034 AutoSECMODListReadLock::AutoSECMODListReadLock()
1035       : lock_(SECMOD_GetDefaultModuleListLock()) {
1036     SECMOD_GetReadLock(lock_);
1037   }
1038
1039 AutoSECMODListReadLock::~AutoSECMODListReadLock() {
1040   SECMOD_ReleaseReadLock(lock_);
1041 }
1042 #endif  // defined(USE_NSS_CERTS)
1043
1044 #if defined(OS_CHROMEOS)
1045 ScopedPK11Slot GetSystemNSSKeySlot(
1046     const base::Callback<void(ScopedPK11Slot)>& callback) {
1047   return g_nss_singleton.Get().GetSystemNSSKeySlot(callback);
1048 }
1049
1050 void SetSystemKeySlotForTesting(ScopedPK11Slot slot) {
1051   g_nss_singleton.Get().SetSystemKeySlotForTesting(slot.Pass());
1052 }
1053
1054 void EnableTPMTokenForNSS() {
1055   g_nss_singleton.Get().EnableTPMTokenForNSS();
1056 }
1057
1058 bool IsTPMTokenEnabledForNSS() {
1059   return g_nss_singleton.Get().IsTPMTokenEnabledForNSS();
1060 }
1061
1062 bool IsTPMTokenReady(const base::Closure& callback) {
1063   return g_nss_singleton.Get().IsTPMTokenReady(callback);
1064 }
1065
1066 void InitializeTPMTokenAndSystemSlot(
1067     int token_slot_id,
1068     const base::Callback<void(bool)>& callback) {
1069   g_nss_singleton.Get().InitializeTPMTokenAndSystemSlot(token_slot_id,
1070                                                         callback);
1071 }
1072
1073 bool InitializeNSSForChromeOSUser(const std::string& username_hash,
1074                                   const base::FilePath& path) {
1075   return g_nss_singleton.Get().InitializeNSSForChromeOSUser(username_hash,
1076                                                             path);
1077 }
1078
1079 bool ShouldInitializeTPMForChromeOSUser(const std::string& username_hash) {
1080   return g_nss_singleton.Get().ShouldInitializeTPMForChromeOSUser(
1081       username_hash);
1082 }
1083
1084 void WillInitializeTPMForChromeOSUser(const std::string& username_hash) {
1085   g_nss_singleton.Get().WillInitializeTPMForChromeOSUser(username_hash);
1086 }
1087
1088 void InitializeTPMForChromeOSUser(
1089     const std::string& username_hash,
1090     CK_SLOT_ID slot_id) {
1091   g_nss_singleton.Get().InitializeTPMForChromeOSUser(username_hash, slot_id);
1092 }
1093
1094 void InitializePrivateSoftwareSlotForChromeOSUser(
1095     const std::string& username_hash) {
1096   g_nss_singleton.Get().InitializePrivateSoftwareSlotForChromeOSUser(
1097       username_hash);
1098 }
1099
1100 ScopedPK11Slot GetPublicSlotForChromeOSUser(const std::string& username_hash) {
1101   return g_nss_singleton.Get().GetPublicSlotForChromeOSUser(username_hash);
1102 }
1103
1104 ScopedPK11Slot GetPrivateSlotForChromeOSUser(
1105     const std::string& username_hash,
1106     const base::Callback<void(ScopedPK11Slot)>& callback) {
1107   return g_nss_singleton.Get().GetPrivateSlotForChromeOSUser(username_hash,
1108                                                              callback);
1109 }
1110
1111 void CloseChromeOSUserForTesting(const std::string& username_hash) {
1112   g_nss_singleton.Get().CloseChromeOSUserForTesting(username_hash);
1113 }
1114 #endif  // defined(OS_CHROMEOS)
1115
1116 base::Time PRTimeToBaseTime(PRTime prtime) {
1117   return base::Time::FromInternalValue(
1118       prtime + base::Time::UnixEpoch().ToInternalValue());
1119 }
1120
1121 PRTime BaseTimeToPRTime(base::Time time) {
1122   return time.ToInternalValue() - base::Time::UnixEpoch().ToInternalValue();
1123 }
1124
1125 #if !defined(OS_CHROMEOS)
1126 PK11SlotInfo* GetPersistentNSSKeySlot() {
1127   return g_nss_singleton.Get().GetPersistentNSSKeySlot();
1128 }
1129 #endif
1130
1131 }  // namespace crypto