client_cert_resolver.cc revision 58537e28ecd584eab876aee8be7156509866d23a 
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/stl_util.h"
15#include "base/task_runner.h"
16#include "base/threading/worker_pool.h"
17#include "base/time/time.h"
18#include "chromeos/cert_loader.h"
19#include "chromeos/dbus/dbus_thread_manager.h"
20#include "chromeos/dbus/shill_service_client.h"
21#include "chromeos/network/certificate_pattern.h"
22#include "chromeos/network/client_cert_util.h"
23#include "chromeos/network/favorite_state.h"
24#include "chromeos/network/managed_network_configuration_handler.h"
25#include "chromeos/network/network_state_handler.h"
26#include "chromeos/network/network_ui_data.h"
27#include "chromeos/network/onc/onc_constants.h"
28#include "dbus/object_path.h"
29#include "net/cert/x509_certificate.h"
30
31namespace chromeos {
32
33// Describes a network |network_path| for which a matching certificate |cert_id|
34// was found.
35struct ClientCertResolver::NetworkAndMatchingCert {
36  NetworkAndMatchingCert(const std::string& network_path,
37                         client_cert::ConfigType config_type,
38                         const std::string& cert_id)
39      : service_path(network_path),
40        cert_config_type(config_type),
41        pkcs11_id(cert_id) {}
42
43  std::string service_path;
44  client_cert::ConfigType cert_config_type;
45  // The id of the matching certificate.
46  std::string pkcs11_id;
47};
48
49typedef std::vector<ClientCertResolver::NetworkAndMatchingCert>
50    NetworkCertMatches;
51
52namespace {
53
54// Returns true if |vector| contains |value|.
55template <class T>
56bool ContainsValue(const std::vector<T>& vector, const T& value) {
57  return find(vector.begin(), vector.end(), value) != vector.end();
58}
59
60// Returns true if a private key for certificate |cert| is installed.
61bool HasPrivateKey(const net::X509Certificate& cert) {
62  PK11SlotInfo* slot = PK11_KeyForCertExists(cert.os_cert_handle(), NULL, NULL);
63  if (!slot)
64    return false;
65
66  PK11_FreeSlot(slot);
67  return true;
68}
69
70// Describes a certificate which is issued by |issuer| (encoded as PEM).
71struct CertAndIssuer {
72  CertAndIssuer(const scoped_refptr<net::X509Certificate>& certificate,
73                const std::string& issuer)
74      : cert(certificate),
75        pem_encoded_issuer(issuer) {}
76
77  scoped_refptr<net::X509Certificate> cert;
78  std::string pem_encoded_issuer;
79};
80
81bool CompareCertExpiration(const CertAndIssuer& a,
82                           const CertAndIssuer& b) {
83  return (a.cert->valid_expiry() < b.cert->valid_expiry());
84}
85
86// Describes a network that is configured with the certificate pattern
87// |client_cert_pattern|.
88struct NetworkAndCertPattern {
89  NetworkAndCertPattern(const std::string& network_path,
90                        client_cert::ConfigType config_type,
91                        const CertificatePattern& pattern)
92      : service_path(network_path),
93        cert_config_type(config_type),
94        client_cert_pattern(pattern) {}
95  std::string service_path;
96  client_cert::ConfigType cert_config_type;
97  CertificatePattern client_cert_pattern;
98};
99
100// A unary predicate that returns true if the given CertAndIssuer matches the
101// certificate pattern of the NetworkAndCertPattern.
102struct MatchCertWithPattern {
103  MatchCertWithPattern(const NetworkAndCertPattern& pattern)
104      : net_and_pattern(pattern) {}
105
106  bool operator()(const CertAndIssuer& cert_and_issuer) {
107    const CertificatePattern& pattern = net_and_pattern.client_cert_pattern;
108    if (!pattern.issuer().Empty() &&
109        !client_cert::CertPrincipalMatches(pattern.issuer(),
110                                           cert_and_issuer.cert->issuer())) {
111      return false;
112    }
113    if (!pattern.subject().Empty() &&
114        !client_cert::CertPrincipalMatches(pattern.subject(),
115                                           cert_and_issuer.cert->subject())) {
116      return false;
117    }
118
119    const std::vector<std::string>& issuer_ca_pems = pattern.issuer_ca_pems();
120    if (!issuer_ca_pems.empty() &&
121        !ContainsValue(issuer_ca_pems, cert_and_issuer.pem_encoded_issuer)) {
122      return false;
123    }
124    return true;
125  }
126
127  NetworkAndCertPattern net_and_pattern;
128};
129
130// Searches for matches between |networks| and |certs| and writes matches to
131// |matches|. Because this calls NSS functions and is potentially slow, it must
132// be run on a worker thread.
133void FindCertificateMatches(const net::CertificateList& certs,
134                            std::vector<NetworkAndCertPattern>* networks,
135                            NetworkCertMatches* matches) {
136  // Filter all client certs and determines each certificate's issuer, which is
137  // required for the pattern matching.
138  std::vector<CertAndIssuer> client_certs;
139  for (net::CertificateList::const_iterator it = certs.begin();
140       it != certs.end(); ++it) {
141    const net::X509Certificate& cert = **it;
142    if (cert.valid_expiry().is_null() || cert.HasExpired() ||
143        !HasPrivateKey(cert)) {
144      continue;
145    }
146    scoped_refptr<net::X509Certificate> issuer =
147        net::X509Certificate::CreateFromHandle(
148            CERT_FindCertIssuer(
149                cert.os_cert_handle(), PR_Now(), certUsageAnyCA),
150            net::X509Certificate::OSCertHandles());
151    if (!issuer) {
152      LOG(ERROR) << "Couldn't find cert issuer.";
153      continue;
154    }
155    std::string pem_encoded_issuer;
156    if (!net::X509Certificate::GetPEMEncoded(issuer->os_cert_handle(),
157                                             &pem_encoded_issuer)) {
158      LOG(ERROR) << "Couldn't PEM-encode certificate.";
159      continue;
160    }
161    client_certs.push_back(CertAndIssuer(*it, pem_encoded_issuer));
162  }
163
164  std::sort(client_certs.begin(), client_certs.end(), &CompareCertExpiration);
165
166  for (std::vector<NetworkAndCertPattern>::const_iterator it =
167           networks->begin();
168       it != networks->end(); ++it) {
169    std::vector<CertAndIssuer>::iterator cert_it = std::find_if(
170        client_certs.begin(), client_certs.end(), MatchCertWithPattern(*it));
171    if (cert_it == client_certs.end()) {
172      LOG(WARNING) << "Couldn't find a matching client cert for network "
173                   << it->service_path;
174      continue;
175    }
176    std::string pkcs11_id = CertLoader::GetPkcs11IdForCert(*cert_it->cert);
177    if (pkcs11_id.empty()) {
178      LOG(ERROR) << "Couldn't determine PKCS#11 ID.";
179      continue;
180    }
181    matches->push_back(ClientCertResolver::NetworkAndMatchingCert(
182        it->service_path, it->cert_config_type, pkcs11_id));
183  }
184}
185
186// Determines the type of the CertificatePattern configuration, i.e. is it a
187// pattern within an EAP, IPsec or OpenVPN configuration.
188client_cert::ConfigType OncToClientCertConfigurationType(
189    const base::DictionaryValue& network_config) {
190  using namespace ::chromeos::onc;
191
192  const base::DictionaryValue* wifi = NULL;
193  network_config.GetDictionaryWithoutPathExpansion(network_config::kWiFi,
194                                                   &wifi);
195  if (wifi) {
196    const base::DictionaryValue* eap = NULL;
197    wifi->GetDictionaryWithoutPathExpansion(wifi::kEAP, &eap);
198    if (!eap)
199      return client_cert::CONFIG_TYPE_NONE;
200    return client_cert::CONFIG_TYPE_EAP;
201  }
202
203  const base::DictionaryValue* vpn = NULL;
204  network_config.GetDictionaryWithoutPathExpansion(network_config::kVPN, &vpn);
205  if (vpn) {
206    const base::DictionaryValue* openvpn = NULL;
207    vpn->GetDictionaryWithoutPathExpansion(vpn::kOpenVPN, &openvpn);
208    if (openvpn)
209      return client_cert::CONFIG_TYPE_OPENVPN;
210
211    const base::DictionaryValue* ipsec = NULL;
212    vpn->GetDictionaryWithoutPathExpansion(vpn::kIPsec, &ipsec);
213    if (ipsec)
214      return client_cert::CONFIG_TYPE_IPSEC;
215
216    return client_cert::CONFIG_TYPE_NONE;
217  }
218
219  const base::DictionaryValue* ethernet = NULL;
220  network_config.GetDictionaryWithoutPathExpansion(network_config::kEthernet,
221                                                   &ethernet);
222  if (ethernet) {
223    const base::DictionaryValue* eap = NULL;
224    ethernet->GetDictionaryWithoutPathExpansion(wifi::kEAP, &eap);
225    if (eap)
226      return client_cert::CONFIG_TYPE_EAP;
227    return client_cert::CONFIG_TYPE_NONE;
228  }
229
230  return client_cert::CONFIG_TYPE_NONE;
231}
232
233void LogError(const std::string& service_path,
234              const std::string& dbus_error_name,
235              const std::string& dbus_error_message) {
236  network_handler::ShillErrorCallbackFunction(
237      "ClientCertResolver.SetProperties failed",
238      service_path,
239      network_handler::ErrorCallback(),
240      dbus_error_name,
241      dbus_error_message);
242}
243
244bool ClientCertificatesLoaded() {
245  if(!CertLoader::Get()->certificates_loaded()) {
246    VLOG(1) << "Certificates not loaded yet.";
247    return false;
248  }
249  if (!CertLoader::Get()->IsHardwareBacked()) {
250    VLOG(1) << "TPM is not available.";
251    return false;
252  }
253  return true;
254}
255
256}  // namespace
257
258ClientCertResolver::ClientCertResolver()
259    : network_state_handler_(NULL),
260      managed_network_config_handler_(NULL),
261      weak_ptr_factory_(this) {
262}
263
264ClientCertResolver::~ClientCertResolver() {
265  if (network_state_handler_)
266    network_state_handler_->RemoveObserver(this, FROM_HERE);
267  if (CertLoader::IsInitialized())
268    CertLoader::Get()->RemoveObserver(this);
269  if (managed_network_config_handler_)
270    managed_network_config_handler_->RemoveObserver(this);
271}
272
273void ClientCertResolver::Init(
274    NetworkStateHandler* network_state_handler,
275    ManagedNetworkConfigurationHandler* managed_network_config_handler) {
276  DCHECK(network_state_handler);
277  network_state_handler_ = network_state_handler;
278  network_state_handler_->AddObserver(this, FROM_HERE);
279
280  DCHECK(managed_network_config_handler);
281  managed_network_config_handler_ = managed_network_config_handler;
282  managed_network_config_handler_->AddObserver(this);
283
284  CertLoader::Get()->AddObserver(this);
285}
286
287void ClientCertResolver::SetSlowTaskRunnerForTest(
288    const scoped_refptr<base::TaskRunner>& task_runner) {
289  slow_task_runner_for_test_ = task_runner;
290}
291
292void ClientCertResolver::NetworkListChanged() {
293  VLOG(2) << "NetworkListChanged.";
294  if (!ClientCertificatesLoaded())
295    return;
296  // Configure only networks that were not configured before.
297
298  // We'll drop networks from |resolved_networks_|, which are not known anymore.
299  std::set<std::string> old_resolved_networks;
300  old_resolved_networks.swap(resolved_networks_);
301
302  FavoriteStateList networks;
303  network_state_handler_->GetFavoriteList(&networks);
304
305  FavoriteStateList networks_to_check;
306  for (FavoriteStateList::const_iterator it = networks.begin();
307       it != networks.end(); ++it) {
308    const std::string& service_path = (*it)->path();
309    if (ContainsKey(old_resolved_networks, service_path)) {
310      resolved_networks_.insert(service_path);
311      continue;
312    }
313    networks_to_check.push_back(*it);
314  }
315
316  ResolveNetworks(networks_to_check);
317}
318
319void ClientCertResolver::OnCertificatesLoaded(
320    const net::CertificateList& cert_list,
321    bool initial_load) {
322  VLOG(2) << "OnCertificatesLoaded.";
323  if (!ClientCertificatesLoaded())
324    return;
325  // Compare all networks with all certificates.
326  FavoriteStateList networks;
327  network_state_handler_->GetFavoriteList(&networks);
328  ResolveNetworks(networks);
329}
330
331void ClientCertResolver::PolicyApplied(const std::string& service_path) {
332  VLOG(2) << "PolicyApplied " << service_path;
333  if (!ClientCertificatesLoaded())
334    return;
335  // Compare this network with all certificates.
336  const FavoriteState* network =
337      network_state_handler_->GetFavoriteState(service_path);
338  if (!network) {
339    LOG(ERROR) << "service path '" << service_path << "' unknown.";
340    return;
341  }
342  FavoriteStateList networks;
343  networks.push_back(network);
344  ResolveNetworks(networks);
345}
346
347void ClientCertResolver::ResolveNetworks(const FavoriteStateList& networks) {
348  scoped_ptr<std::vector<NetworkAndCertPattern> > networks_with_pattern(
349      new std::vector<NetworkAndCertPattern>);
350
351  // Filter networks with ClientCertPattern. As ClientCertPatterns can only be
352  // set by policy, we check there.
353  for (FavoriteStateList::const_iterator it = networks.begin();
354       it != networks.end(); ++it) {
355    const FavoriteState* network = *it;
356
357    // In any case, don't check this network again in NetworkListChanged.
358    resolved_networks_.insert(network->path());
359
360    // If this network is not managed, it cannot have a ClientCertPattern.
361    if (network->guid().empty())
362      continue;
363
364    if (network->profile_path().empty()) {
365      LOG(ERROR) << "Network " << network->path()
366                 << " has a GUID but not profile path";
367      continue;
368    }
369    const base::DictionaryValue* policy =
370        managed_network_config_handler_->FindPolicyByGuidAndProfile(
371            network->guid(), network->profile_path());
372
373    if (!policy) {
374      VLOG(1) << "The policy for network " << network->path() << " with GUID "
375              << network->guid() << " is not available yet.";
376      // Skip this network for now. Once the policy is loaded, PolicyApplied()
377      // will retry.
378      continue;
379    }
380
381    VLOG(2) << "Inspecting network " << network->path();
382    // TODO(pneubeck): Access the ClientCertPattern without relying on
383    //   NetworkUIData, which also parses other things that we don't need here.
384    // The ONCSource is irrelevant here.
385    scoped_ptr<NetworkUIData> ui_data(
386        NetworkUIData::CreateFromONC(onc::ONC_SOURCE_NONE, *policy));
387
388    // Skip networks that don't have a ClientCertPattern.
389    if (ui_data->certificate_type() != CLIENT_CERT_TYPE_PATTERN)
390      continue;
391
392    client_cert::ConfigType config_type =
393        OncToClientCertConfigurationType(*policy);
394    if (config_type == client_cert::CONFIG_TYPE_NONE) {
395      LOG(ERROR) << "UIData contains a CertificatePattern, but the policy "
396                 << "doesn't. Network: " << network->path();
397      continue;
398    }
399
400    networks_with_pattern->push_back(NetworkAndCertPattern(
401        network->path(), config_type, ui_data->certificate_pattern()));
402  }
403  if (networks_with_pattern->empty())
404    return;
405
406  VLOG(2) << "Start task for resolving client cert patterns.";
407  base::TaskRunner* task_runner = slow_task_runner_for_test_.get();
408  if (!task_runner)
409    task_runner = base::WorkerPool::GetTaskRunner(true /* task is slow */);
410
411  NetworkCertMatches* matches = new NetworkCertMatches;
412  task_runner->PostTaskAndReply(
413      FROM_HERE,
414      base::Bind(&FindCertificateMatches,
415                 CertLoader::Get()->cert_list(),
416                 base::Owned(networks_with_pattern.release()),
417                 matches),
418      base::Bind(&ClientCertResolver::ConfigureCertificates,
419                 weak_ptr_factory_.GetWeakPtr(),
420                 base::Owned(matches)));
421}
422
423void ClientCertResolver::ConfigureCertificates(NetworkCertMatches* matches) {
424  for (NetworkCertMatches::const_iterator it = matches->begin();
425       it != matches->end(); ++it) {
426    VLOG(1) << "Configuring certificate of network " << it->service_path;
427    CertLoader* cert_loader = CertLoader::Get();
428    base::DictionaryValue shill_properties;
429    client_cert::SetShillProperties(it->cert_config_type,
430                                    cert_loader->tpm_token_slot(),
431                                    cert_loader->tpm_user_pin(),
432                                    &it->pkcs11_id,
433                                    &shill_properties);
434    DBusThreadManager::Get()->GetShillServiceClient()->
435        SetProperties(dbus::ObjectPath(it->service_path),
436                        shill_properties,
437                        base::Bind(&base::DoNothing),
438                        base::Bind(&LogError, it->service_path));
439    network_state_handler_->RequestUpdateForNetwork(it->service_path);
440  }
441}
442
443}  // namespace chromeos
444