src/chromeos/network/client_cert_resolver.cc

   1 // Copyright 2013 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 "chromeos/network/client_cert_resolver.h"
   6
   7 #include <cert.h>
   8 #include <certt.h>  // for (SECCertUsageEnum) certUsageAnyCA
   9 #include <pk11pub.h>
  10
  11 #include <algorithm>
  12 #include <string>
  13
  14 #include "base/bind.h"
  15 #include "base/location.h"
  16 #include "base/logging.h"
  17 #include "base/stl_util.h"
  18 #include "base/task_runner.h"
  19 #include "base/threading/worker_pool.h"
  20 #include "chromeos/cert_loader.h"
  21 #include "chromeos/dbus/dbus_thread_manager.h"
  22 #include "chromeos/dbus/shill_service_client.h"
  23 #include "chromeos/network/managed_network_configuration_handler.h"
  24 #include "chromeos/network/network_state.h"
  25 #include "components/onc/onc_constants.h"
  26 #include "dbus/object_path.h"
  27 #include "net/cert/scoped_nss_types.h"
  28 #include "net/cert/x509_certificate.h"
  29
  30 namespace chromeos {
  31
  32 // Describes a network |network_path| for which a matching certificate |cert_id|
  33 // was found or for which no certificate was found (|cert_id| will be empty).
  34 struct ClientCertResolver::NetworkAndMatchingCert {
  35   NetworkAndMatchingCert(const std::string& network_path,
  36                          client_cert::ConfigType config_type,
  37                          const std::string& cert_id,
  38                          int slot_id)
  39       : service_path(network_path),
  40         cert_config_type(config_type),
  41         pkcs11_id(cert_id),
  42         key_slot_id(slot_id) {}
  43
  44   std::string service_path;
  45   client_cert::ConfigType cert_config_type;
  46
  47   // The id of the matching certificate or empty if no certificate was found.
  48   std::string pkcs11_id;
  49
  50   // The id of the slot containing the certificate and the private key.
  51   int key_slot_id;
  52 };
  53
  54 typedef std::vector<ClientCertResolver::NetworkAndMatchingCert>
  55     NetworkCertMatches;
  56
  57 namespace {
  58
  59 // Returns true if |vector| contains |value|.
  60 template <class T>
  61 bool ContainsValue(const std::vector<T>& vector, const T& value) {
  62   return find(vector.begin(), vector.end(), value) != vector.end();
  63 }
  64
  65 // Returns true if a private key for certificate |cert| is installed.
  66 bool HasPrivateKey(const net::X509Certificate& cert) {
  67   PK11SlotInfo* slot = PK11_KeyForCertExists(cert.os_cert_handle(), NULL, NULL);
  68   if (!slot)
  69     return false;
  70
  71   PK11_FreeSlot(slot);
  72   return true;
  73 }
  74
  75 // Describes a certificate which is issued by |issuer| (encoded as PEM).
  76 struct CertAndIssuer {
  77   CertAndIssuer(const scoped_refptr<net::X509Certificate>& certificate,
  78                 const std::string& issuer)
  79       : cert(certificate),
  80         pem_encoded_issuer(issuer) {}
  81
  82   scoped_refptr<net::X509Certificate> cert;
  83   std::string pem_encoded_issuer;
  84 };
  85
  86 bool CompareCertExpiration(const CertAndIssuer& a,
  87                            const CertAndIssuer& b) {
  88   return (a.cert->valid_expiry() > b.cert->valid_expiry());
  89 }
  90
  91 // Describes a network that is configured with the certificate pattern
  92 // |client_cert_pattern|.
  93 struct NetworkAndCertPattern {
  94   NetworkAndCertPattern(const std::string& network_path,
  95                         const client_cert::ClientCertConfig& client_cert_config)
  96       : service_path(network_path),
  97         cert_config(client_cert_config) {}
  98
  99   std::string service_path;
 100   client_cert::ClientCertConfig cert_config;
 101 };
 102
 103 // A unary predicate that returns true if the given CertAndIssuer matches the
 104 // given certificate pattern.
 105 struct MatchCertWithPattern {
 106   explicit MatchCertWithPattern(const CertificatePattern& cert_pattern)
 107       : pattern(cert_pattern) {}
 108
 109   bool operator()(const CertAndIssuer& cert_and_issuer) {
 110     if (!pattern.issuer().Empty() &&
 111         !client_cert::CertPrincipalMatches(pattern.issuer(),
 112                                            cert_and_issuer.cert->issuer())) {
 113       return false;
 114     }
 115     if (!pattern.subject().Empty() &&
 116         !client_cert::CertPrincipalMatches(pattern.subject(),
 117                                            cert_and_issuer.cert->subject())) {
 118       return false;
 119     }
 120
 121     const std::vector<std::string>& issuer_ca_pems = pattern.issuer_ca_pems();
 122     if (!issuer_ca_pems.empty() &&
 123         !ContainsValue(issuer_ca_pems, cert_and_issuer.pem_encoded_issuer)) {
 124       return false;
 125     }
 126     return true;
 127   }
 128
 129   const CertificatePattern pattern;
 130 };
 131
 132 std::vector<CertAndIssuer> CreateSortedCertAndIssuerList(
 133     const net::CertificateList& certs) {
 134   // Filter all client certs and determines each certificate's issuer, which is
 135   // required for the pattern matching.
 136   std::vector<CertAndIssuer> client_certs;
 137   for (net::CertificateList::const_iterator it = certs.begin();
 138        it != certs.end(); ++it) {
 139     const net::X509Certificate& cert = **it;
 140     if (cert.valid_expiry().is_null() || cert.HasExpired() ||
 141         !HasPrivateKey(cert) ||
 142         !CertLoader::IsCertificateHardwareBacked(&cert)) {
 143       continue;
 144     }
 145     net::ScopedCERTCertificate issuer_handle(
 146         CERT_FindCertIssuer(cert.os_cert_handle(), PR_Now(), certUsageAnyCA));
 147     if (!issuer_handle) {
 148       LOG(ERROR) << "Couldn't find an issuer.";
 149       continue;
 150     }
 151     scoped_refptr<net::X509Certificate> issuer =
 152         net::X509Certificate::CreateFromHandle(
 153             issuer_handle.get(),
 154             net::X509Certificate::OSCertHandles() /* no intermediate certs */);
 155     if (!issuer.get()) {
 156       LOG(ERROR) << "Couldn't create issuer cert.";
 157       continue;
 158     }
 159     std::string pem_encoded_issuer;
 160     if (!net::X509Certificate::GetPEMEncoded(issuer->os_cert_handle(),
 161                                              &pem_encoded_issuer)) {
 162       LOG(ERROR) << "Couldn't PEM-encode certificate.";
 163       continue;
 164     }
 165     client_certs.push_back(CertAndIssuer(*it, pem_encoded_issuer));
 166   }
 167
 168   std::sort(client_certs.begin(), client_certs.end(), &CompareCertExpiration);
 169   return client_certs;
 170 }
 171
 172 // Searches for matches between |networks| and |certs| and writes matches to
 173 // |matches|. Because this calls NSS functions and is potentially slow, it must
 174 // be run on a worker thread.
 175 void FindCertificateMatches(const net::CertificateList& certs,
 176                             std::vector<NetworkAndCertPattern>* networks,
 177                             NetworkCertMatches* matches) {
 178   std::vector<CertAndIssuer> client_certs(CreateSortedCertAndIssuerList(certs));
 179
 180   for (std::vector<NetworkAndCertPattern>::const_iterator it =
 181            networks->begin();
 182        it != networks->end(); ++it) {
 183     std::vector<CertAndIssuer>::iterator cert_it =
 184         std::find_if(client_certs.begin(),
 185                      client_certs.end(),
 186                      MatchCertWithPattern(it->cert_config.pattern));
 187     std::string pkcs11_id;
 188     int slot_id = -1;
 189     if (cert_it == client_certs.end()) {
 190       VLOG(1) << "Couldn't find a matching client cert for network "
 191               << it->service_path;
 192       // Leave |pkcs11_id| empty to indicate that no cert was found for this
 193       // network.
 194     } else {
 195       pkcs11_id =
 196           CertLoader::GetPkcs11IdAndSlotForCert(*cert_it->cert, &slot_id);
 197       if (pkcs11_id.empty()) {
 198         LOG(ERROR) << "Couldn't determine PKCS#11 ID.";
 199         // So far this error is not expected to happen. We can just continue, in
 200         // the worst case the user can remove the problematic cert.
 201         continue;
 202       }
 203     }
 204     matches->push_back(ClientCertResolver::NetworkAndMatchingCert(
 205         it->service_path, it->cert_config.location, pkcs11_id, slot_id));
 206   }
 207 }
 208
 209 void LogError(const std::string& service_path,
 210               const std::string& dbus_error_name,
 211               const std::string& dbus_error_message) {
 212   network_handler::ShillErrorCallbackFunction(
 213       "ClientCertResolver.SetProperties failed",
 214       service_path,
 215       network_handler::ErrorCallback(),
 216       dbus_error_name,
 217       dbus_error_message);
 218 }
 219
 220 bool ClientCertificatesLoaded() {
 221   if (!CertLoader::Get()->certificates_loaded()) {
 222     VLOG(1) << "Certificates not loaded yet.";
 223     return false;
 224   }
 225   return true;
 226 }
 227
 228 }  // namespace
 229
 230 ClientCertResolver::ClientCertResolver()
 231     : resolve_task_running_(false),
 232       network_properties_changed_(false),
 233       network_state_handler_(NULL),
 234       managed_network_config_handler_(NULL),
 235       weak_ptr_factory_(this) {
 236 }
 237
 238 ClientCertResolver::~ClientCertResolver() {
 239   if (network_state_handler_)
 240     network_state_handler_->RemoveObserver(this, FROM_HERE);
 241   if (CertLoader::IsInitialized())
 242     CertLoader::Get()->RemoveObserver(this);
 243   if (managed_network_config_handler_)
 244     managed_network_config_handler_->RemoveObserver(this);
 245 }
 246
 247 void ClientCertResolver::Init(
 248     NetworkStateHandler* network_state_handler,
 249     ManagedNetworkConfigurationHandler* managed_network_config_handler) {
 250   DCHECK(network_state_handler);
 251   network_state_handler_ = network_state_handler;
 252   network_state_handler_->AddObserver(this, FROM_HERE);
 253
 254   DCHECK(managed_network_config_handler);
 255   managed_network_config_handler_ = managed_network_config_handler;
 256   managed_network_config_handler_->AddObserver(this);
 257
 258   CertLoader::Get()->AddObserver(this);
 259 }
 260
 261 void ClientCertResolver::SetSlowTaskRunnerForTest(
 262     const scoped_refptr<base::TaskRunner>& task_runner) {
 263   slow_task_runner_for_test_ = task_runner;
 264 }
 265
 266 void ClientCertResolver::AddObserver(Observer* observer) {
 267   observers_.AddObserver(observer);
 268 }
 269
 270 void ClientCertResolver::RemoveObserver(Observer* observer) {
 271   observers_.RemoveObserver(observer);
 272 }
 273
 274 bool ClientCertResolver::IsAnyResolveTaskRunning() const {
 275   return resolve_task_running_;
 276 }
 277
 278 // static
 279 bool ClientCertResolver::ResolveCertificatePatternSync(
 280     const client_cert::ConfigType client_cert_type,
 281     const CertificatePattern& pattern,
 282     base::DictionaryValue* shill_properties) {
 283   // Prepare and sort the list of known client certs.
 284   std::vector<CertAndIssuer> client_certs(
 285       CreateSortedCertAndIssuerList(CertLoader::Get()->cert_list()));
 286
 287   // Search for a certificate matching the pattern.
 288   std::vector<CertAndIssuer>::iterator cert_it = std::find_if(
 289       client_certs.begin(), client_certs.end(), MatchCertWithPattern(pattern));
 290
 291   if (cert_it == client_certs.end()) {
 292     VLOG(1) << "Couldn't find a matching client cert";
 293     client_cert::SetEmptyShillProperties(client_cert_type, shill_properties);
 294     return false;
 295   }
 296
 297   int slot_id = -1;
 298   std::string pkcs11_id =
 299       CertLoader::GetPkcs11IdAndSlotForCert(*cert_it->cert, &slot_id);
 300   if (pkcs11_id.empty()) {
 301     LOG(ERROR) << "Couldn't determine PKCS#11 ID.";
 302     // So far this error is not expected to happen. We can just continue, in
 303     // the worst case the user can remove the problematic cert.
 304     return false;
 305   }
 306   client_cert::SetShillProperties(
 307       client_cert_type, slot_id, pkcs11_id, shill_properties);
 308   return true;
 309 }
 310
 311 void ClientCertResolver::NetworkListChanged() {
 312   VLOG(2) << "NetworkListChanged.";
 313   if (!ClientCertificatesLoaded())
 314     return;
 315   // Configure only networks that were not configured before.
 316
 317   // We'll drop networks from |resolved_networks_|, which are not known anymore.
 318   std::set<std::string> old_resolved_networks;
 319   old_resolved_networks.swap(resolved_networks_);
 320
 321   NetworkStateHandler::NetworkStateList networks;
 322   network_state_handler_->GetNetworkListByType(
 323       NetworkTypePattern::Default(),
 324       true /* configured_only */,
 325       false /* visible_only */,
 326       0 /* no limit */,
 327       &networks);
 328
 329   NetworkStateHandler::NetworkStateList networks_to_check;
 330   for (NetworkStateHandler::NetworkStateList::const_iterator it =
 331            networks.begin(); it != networks.end(); ++it) {
 332     const std::string& service_path = (*it)->path();
 333     if (ContainsKey(old_resolved_networks, service_path)) {
 334       resolved_networks_.insert(service_path);
 335       continue;
 336     }
 337     networks_to_check.push_back(*it);
 338   }
 339
 340   ResolveNetworks(networks_to_check);
 341 }
 342
 343 void ClientCertResolver::OnCertificatesLoaded(
 344     const net::CertificateList& cert_list,
 345     bool initial_load) {
 346   VLOG(2) << "OnCertificatesLoaded.";
 347   if (!ClientCertificatesLoaded())
 348     return;
 349   // Compare all networks with all certificates.
 350   NetworkStateHandler::NetworkStateList networks;
 351   network_state_handler_->GetNetworkListByType(
 352       NetworkTypePattern::Default(),
 353       true /* configured_only */,
 354       false /* visible_only */,
 355       0 /* no limit */,
 356       &networks);
 357   ResolveNetworks(networks);
 358 }
 359
 360 void ClientCertResolver::PolicyAppliedToNetwork(
 361     const std::string& service_path) {
 362   VLOG(2) << "PolicyAppliedToNetwork " << service_path;
 363   if (!ClientCertificatesLoaded())
 364     return;
 365   // Compare this network with all certificates.
 366   const NetworkState* network =
 367       network_state_handler_->GetNetworkStateFromServicePath(
 368           service_path, true /* configured_only */);
 369   if (!network) {
 370     LOG(ERROR) << "service path '" << service_path << "' unknown.";
 371     return;
 372   }
 373   NetworkStateHandler::NetworkStateList networks;
 374   networks.push_back(network);
 375   ResolveNetworks(networks);
 376 }
 377
 378 void ClientCertResolver::ResolveNetworks(
 379     const NetworkStateHandler::NetworkStateList& networks) {
 380   scoped_ptr<std::vector<NetworkAndCertPattern>> networks_to_resolve(
 381       new std::vector<NetworkAndCertPattern>);
 382
 383   // Filter networks with ClientCertPattern. As ClientCertPatterns can only be
 384   // set by policy, we check there.
 385   for (NetworkStateHandler::NetworkStateList::const_iterator it =
 386            networks.begin(); it != networks.end(); ++it) {
 387     const NetworkState* network = *it;
 388
 389     // In any case, don't check this network again in NetworkListChanged.
 390     resolved_networks_.insert(network->path());
 391
 392     // If this network is not configured, it cannot have a ClientCertPattern.
 393     if (network->profile_path().empty())
 394       continue;
 395
 396     const base::DictionaryValue* policy =
 397         managed_network_config_handler_->FindPolicyByGuidAndProfile(
 398             network->guid(), network->profile_path());
 399
 400     if (!policy) {
 401       VLOG(1) << "The policy for network " << network->path() << " with GUID "
 402               << network->guid() << " is not available yet.";
 403       // Skip this network for now. Once the policy is loaded, PolicyApplied()
 404       // will retry.
 405       continue;
 406     }
 407
 408     VLOG(2) << "Inspecting network " << network->path();
 409     client_cert::ClientCertConfig cert_config;
 410     OncToClientCertConfig(*policy, &cert_config);
 411
 412     // Skip networks that don't have a ClientCertPattern.
 413     if (cert_config.client_cert_type != ::onc::client_cert::kPattern)
 414       continue;
 415
 416     networks_to_resolve->push_back(
 417         NetworkAndCertPattern(network->path(), cert_config));
 418   }
 419
 420   if (networks_to_resolve->empty()) {
 421     VLOG(1) << "No networks to resolve.";
 422     NotifyResolveRequestCompleted();
 423     return;
 424   }
 425
 426   if (resolve_task_running_) {
 427     VLOG(1) << "A resolve task is already running. Queue this request.";
 428     for (const NetworkAndCertPattern& network_and_pattern :
 429          *networks_to_resolve) {
 430       queued_networks_to_resolve_.insert(network_and_pattern.service_path);
 431     }
 432     return;
 433   }
 434
 435   VLOG(2) << "Start task for resolving client cert patterns.";
 436   base::TaskRunner* task_runner = slow_task_runner_for_test_.get();
 437   if (!task_runner)
 438     task_runner =
 439         base::WorkerPool::GetTaskRunner(true /* task is slow */).get();
 440
 441   resolve_task_running_ = true;
 442   NetworkCertMatches* matches = new NetworkCertMatches;
 443   task_runner->PostTaskAndReply(
 444       FROM_HERE,
 445       base::Bind(&FindCertificateMatches,
 446                  CertLoader::Get()->cert_list(),
 447                  base::Owned(networks_to_resolve.release()),
 448                  matches),
 449       base::Bind(&ClientCertResolver::ConfigureCertificates,
 450                  weak_ptr_factory_.GetWeakPtr(),
 451                  base::Owned(matches)));
 452 }
 453
 454 void ClientCertResolver::ResolvePendingNetworks() {
 455   NetworkStateHandler::NetworkStateList networks;
 456   network_state_handler_->GetNetworkListByType(NetworkTypePattern::Default(),
 457                                                true /* configured_only */,
 458                                                false /* visible_only */,
 459                                                0 /* no limit */,
 460                                                &networks);
 461
 462   NetworkStateHandler::NetworkStateList networks_to_resolve;
 463   for (const NetworkState* network : networks) {
 464     if (queued_networks_to_resolve_.count(network->path()) > 0)
 465       networks_to_resolve.push_back(network);
 466   }
 467   VLOG(1) << "Resolve pending " << networks_to_resolve.size() << " networks.";
 468   queued_networks_to_resolve_.clear();
 469   ResolveNetworks(networks_to_resolve);
 470 }
 471
 472 void ClientCertResolver::ConfigureCertificates(NetworkCertMatches* matches) {
 473   for (NetworkCertMatches::const_iterator it = matches->begin();
 474        it != matches->end(); ++it) {
 475     VLOG(1) << "Configuring certificate of network " << it->service_path;
 476     base::DictionaryValue shill_properties;
 477     if (it->pkcs11_id.empty()) {
 478       client_cert::SetEmptyShillProperties(it->cert_config_type,
 479                                            &shill_properties);
 480     } else {
 481       client_cert::SetShillProperties(it->cert_config_type,
 482                                       it->key_slot_id,
 483                                       it->pkcs11_id,
 484                                       &shill_properties);
 485     }
 486     network_properties_changed_ = true;
 487     DBusThreadManager::Get()->GetShillServiceClient()->
 488         SetProperties(dbus::ObjectPath(it->service_path),
 489                         shill_properties,
 490                         base::Bind(&base::DoNothing),
 491                         base::Bind(&LogError, it->service_path));
 492     network_state_handler_->RequestUpdateForNetwork(it->service_path);
 493   }
 494   if (queued_networks_to_resolve_.empty())
 495     NotifyResolveRequestCompleted();
 496   else
 497     ResolvePendingNetworks();
 498 }
 499
 500 void ClientCertResolver::NotifyResolveRequestCompleted() {
 501   VLOG(2) << "Notify observers: " << (network_properties_changed_ ? "" : "no ")
 502           << "networks changed.";
 503   resolve_task_running_ = false;
 504   const bool changed = network_properties_changed_;
 505   network_properties_changed_ = false;
 506   FOR_EACH_OBSERVER(Observer, observers_, ResolveRequestCompleted(changed));
 507 }
 508
 509 }  // namespace chromeos