chromeos/cert_loader.cc

   1 // Copyright (c) 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/cert_loader.h"
   6
   7 #include <algorithm>
   8
   9 #include "base/bind.h"
  10 #include "base/location.h"
  11 #include "base/message_loop/message_loop_proxy.h"
  12 #include "base/strings/string_number_conversions.h"
  13 #include "base/task_runner_util.h"
  14 #include "base/threading/worker_pool.h"
  15 #include "crypto/nss_util.h"
  16 #include "crypto/scoped_nss_types.h"
  17 #include "net/cert/nss_cert_database.h"
  18 #include "net/cert/nss_cert_database_chromeos.h"
  19 #include "net/cert/x509_certificate.h"
  20
  21 namespace chromeos {
  22
  23 static CertLoader* g_cert_loader = NULL;
  24
  25 // static
  26 void CertLoader::Initialize() {
  27   CHECK(!g_cert_loader);
  28   g_cert_loader = new CertLoader();
  29 }
  30
  31 // static
  32 void CertLoader::Shutdown() {
  33   CHECK(g_cert_loader);
  34   delete g_cert_loader;
  35   g_cert_loader = NULL;
  36 }
  37
  38 // static
  39 CertLoader* CertLoader::Get() {
  40   CHECK(g_cert_loader) << "CertLoader::Get() called before Initialize()";
  41   return g_cert_loader;
  42 }
  43
  44 // static
  45 bool CertLoader::IsInitialized() {
  46   return g_cert_loader;
  47 }
  48
  49 CertLoader::CertLoader()
  50     : certificates_loaded_(false),
  51       certificates_update_required_(false),
  52       certificates_update_running_(false),
  53       database_(NULL),
  54       force_hardware_backed_for_test_(false),
  55       cert_list_(new net::CertificateList),
  56       weak_factory_(this) {
  57 }
  58
  59 CertLoader::~CertLoader() {
  60   net::CertDatabase::GetInstance()->RemoveObserver(this);
  61 }
  62
  63 void CertLoader::StartWithNSSDB(net::NSSCertDatabase* database) {
  64   CHECK(!database_);
  65   database_ = database;
  66
  67   // Start observing cert database for changes.
  68   // Observing net::CertDatabase is preferred over observing |database_|
  69   // directly, as |database_| observers receive only events generated directly
  70   // by |database_|, so they may miss a few relevant ones.
  71   // TODO(tbarzic): Once singleton NSSCertDatabase is removed, investigate if
  72   // it would be OK to observe |database_| directly; or change NSSCertDatabase
  73   // to send notification on all relevant changes.
  74   net::CertDatabase::GetInstance()->AddObserver(this);
  75
  76   LoadCertificates();
  77 }
  78
  79 void CertLoader::AddObserver(CertLoader::Observer* observer) {
  80   observers_.AddObserver(observer);
  81 }
  82
  83 void CertLoader::RemoveObserver(CertLoader::Observer* observer) {
  84   observers_.RemoveObserver(observer);
  85 }
  86
  87 bool CertLoader::IsHardwareBacked() const {
  88   if (force_hardware_backed_for_test_)
  89     return true;
  90   if (!database_)
  91     return false;
  92   crypto::ScopedPK11Slot slot(database_->GetPrivateSlot());
  93   if (!slot)
  94     return false;
  95   return PK11_IsHW(slot.get());
  96 }
  97
  98 bool CertLoader::IsCertificateHardwareBacked(
  99     const net::X509Certificate* cert) const {
 100   if (!database_)
 101     return false;
 102   return database_->IsHardwareBacked(cert);
 103 }
 104
 105 bool CertLoader::CertificatesLoading() const {
 106   return database_ && !certificates_loaded_;
 107 }
 108
 109 // static
 110 //
 111 // For background see this discussion on dev-tech-crypto.lists.mozilla.org:
 112 // http://web.archiveorange.com/archive/v/6JJW7E40sypfZGtbkzxX
 113 //
 114 // NOTE: This function relies on the convention that the same PKCS#11 ID
 115 // is shared between a certificate and its associated private and public
 116 // keys.  I tried to implement this with PK11_GetLowLevelKeyIDForCert(),
 117 // but that always returns NULL on Chrome OS for me.
 118 std::string CertLoader::GetPkcs11IdAndSlotForCert(
 119     const net::X509Certificate& cert,
 120     int* slot_id) {
 121   DCHECK(slot_id);
 122
 123   CERTCertificateStr* cert_handle = cert.os_cert_handle();
 124   SECKEYPrivateKey *priv_key =
 125       PK11_FindKeyByAnyCert(cert_handle, NULL /* wincx */);
 126   if (!priv_key)
 127     return std::string();
 128
 129   *slot_id = static_cast<int>(PK11_GetSlotID(priv_key->pkcs11Slot));
 130
 131   // Get the CKA_ID attribute for a key.
 132   SECItem* sec_item = PK11_GetLowLevelKeyIDForPrivateKey(priv_key);
 133   std::string pkcs11_id;
 134   if (sec_item) {
 135     pkcs11_id = base::HexEncode(sec_item->data, sec_item->len);
 136     SECITEM_FreeItem(sec_item, PR_TRUE);
 137   }
 138   SECKEY_DestroyPrivateKey(priv_key);
 139
 140   return pkcs11_id;
 141 }
 142
 143 void CertLoader::LoadCertificates() {
 144   CHECK(thread_checker_.CalledOnValidThread());
 145   VLOG(1) << "LoadCertificates: " << certificates_update_running_;
 146
 147   if (certificates_update_running_) {
 148     certificates_update_required_ = true;
 149     return;
 150   }
 151
 152   certificates_update_running_ = true;
 153   certificates_update_required_ = false;
 154
 155   database_->ListCerts(
 156       base::Bind(&CertLoader::UpdateCertificates, weak_factory_.GetWeakPtr()));
 157 }
 158
 159 void CertLoader::UpdateCertificates(
 160     scoped_ptr<net::CertificateList> cert_list) {
 161   CHECK(thread_checker_.CalledOnValidThread());
 162   DCHECK(certificates_update_running_);
 163   VLOG(1) << "UpdateCertificates: " << cert_list->size();
 164
 165   // Ignore any existing certificates.
 166   cert_list_ = cert_list.Pass();
 167
 168   bool initial_load = !certificates_loaded_;
 169   certificates_loaded_ = true;
 170   NotifyCertificatesLoaded(initial_load);
 171
 172   certificates_update_running_ = false;
 173   if (certificates_update_required_)
 174     LoadCertificates();
 175 }
 176
 177 void CertLoader::NotifyCertificatesLoaded(bool initial_load) {
 178   FOR_EACH_OBSERVER(Observer, observers_,
 179                     OnCertificatesLoaded(*cert_list_, initial_load));
 180 }
 181
 182 void CertLoader::OnCACertChanged(const net::X509Certificate* cert) {
 183   // This is triggered when a CA certificate is modified.
 184   VLOG(1) << "OnCACertChanged";
 185   LoadCertificates();
 186 }
 187
 188 void CertLoader::OnCertAdded(const net::X509Certificate* cert) {
 189   // This is triggered when a client certificate is added.
 190   VLOG(1) << "OnCertAdded";
 191   LoadCertificates();
 192 }
 193
 194 void CertLoader::OnCertRemoved(const net::X509Certificate* cert) {
 195   VLOG(1) << "OnCertRemoved";
 196   LoadCertificates();
 197 }
 198
 199 }  // namespace chromeos