securityd/src/pcscmonitor.cpp

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  23
  24
  25 //
  26 // pcscmonitor - use PCSC to monitor smartcard reader/card state for securityd
  27 //
  28 // PCSCMonitor is the "glue" between PCSC and the securityd objects representing
  29 // smartcard-related things. Its job is to manage the daemon and translate real-world
  30 // events (such as card and device insertions) into the securityd object web.
  31 //
  32 #include "pcscmonitor.h"
  33 #include <security_utilities/logging.h>
  34
  35 //
  36 // Construct a PCSCMonitor.
  37 // We strongly assume there's only one of us around here.
  38 //
  39 // Note that this constructor may well run before the server loop has started.
  40 // Don't call anything here that requires an active server loop (like Server::active()).
  41 // In fact, you should push all the hard work into a timer, so as not to hold up the
  42 // general startup process.
  43 //
  44 PCSCMonitor::PCSCMonitor(Server &server, const char* pathToCache, ServiceLevel level)
  45         : Listener(kNotificationDomainPCSC, SecurityServer::kNotificationAllEvents),
  46       server(server),
  47           mServiceLevel(level),
  48       MachServer::Timer(true),
  49           mCachePath(pathToCache),
  50           mTokenCache(NULL)
  51 {
  52         // do all the smartcard-related work once the event loop has started
  53         server.setTimer(this, Time::now());             // ASAP
  54 }
  55
  56 PCSCMonitor::Watcher::Watcher(Server &server, TokenCache &tokenCache, ReaderMap& readers)
  57   : mServer(server), mTokenCache(tokenCache), mReaders(readers)
  58 {}
  59
  60 //
  61 // Poll PCSC for smartcard status.
  62 // We are enumerating all readers on each call.
  63 //
  64 void PCSCMonitor::Watcher::action()
  65 {
  66     // Associate this watching thread with the server, so that it is possible to call
  67     // Server::active() from inside code called from this thread.
  68     mServer.associateThread();
  69
  70     try {
  71         // open PCSC session
  72         mSession.open();
  73
  74         // Array of states, userData() points to associated Reader instance,
  75         // name points to string held by Reader::name attribute.
  76         vector<PCSC::ReaderState> states;
  77
  78         for (;;) {
  79             // enumerate all current readers.
  80             vector<string> names;
  81             mSession.listReaders(names);
  82             secdebug("pcsc", "%ld reader(s) in system", names.size());
  83
  84             // Update PCSC states array with new/removed readers.
  85             for (vector<PCSC::ReaderState>::iterator stateIt = states.begin(); stateIt != states.end(); ) {
  86                 Reader *reader = stateIt->userData<Reader>();
  87                 vector<string>::iterator nameIt = find(names.begin(), names.end(), reader->name());
  88                 if (nameIt == names.end()) {
  89                     // Reader was removed from the system.
  90                     if (Reader *reader = stateIt->userData<Reader>()) {
  91                         secdebug("pcsc", "removing reader %s", stateIt->name());
  92                         Syslog::notice("Token reader %s removed from system", stateIt->name());
  93                         reader->kill();                                         // prepare to die
  94                         mReaders.erase(reader->name());         // remove from reader map
  95                         stateIt = states.erase(stateIt);
  96                     }
  97                 } else {
  98                     // This reader is already tracked, copy its signalled state into the last known state.
  99                     stateIt->lastKnown(stateIt->state());
 100                     names.erase(nameIt);
 101                     stateIt++;
 102                 }
 103             }
 104
 105             // Add states for remaining (newly appeared) reader names.
 106             for (vector<string>::iterator it = names.begin(); it != names.end(); ++it) {
 107                 PCSC::ReaderState state;
 108                 state.clearPod();
 109                 state.set(it->c_str());
 110                 states.push_back(state);
 111             }
 112
 113             // Now ask PCSC for status changes, and wait for them.
 114             mSession.statusChange(states, INFINITE);
 115
 116             // Go through the states and notify changed readers.
 117             for (vector<PCSC::ReaderState>::iterator stateIt = states.begin(); stateIt != states.end(); stateIt++) {
 118                 Reader *reader = stateIt->userData<Reader>();
 119                 if (!reader) {
 120                     reader = new Reader(mTokenCache, *stateIt);
 121                     stateIt->userData<Reader>() = reader;
 122                     stateIt->name(reader->name().c_str());
 123                     mReaders.insert(make_pair(reader->name(), reader));
 124                     Syslog::notice("Token reader %s inserted into system", stateIt->name());
 125                 }
 126
 127                 // if PCSC flags a change, notify the Reader
 128                 if (stateIt->changed()) {
 129                     Syslog::notice("reader %s: state changed %lu -> %lu", stateIt->name(), stateIt->lastKnown(), stateIt->state());
 130                     try {
 131                         reader->update(*stateIt);
 132                     } catch (const exception &e) {
 133                         Syslog::notice("Token in reader %s: %s", stateIt->name(), e.what());
 134                     }
 135                 }
 136             }
 137
 138             //wakeup mach server to process notifications
 139             ClientSession session(Allocator::standard(), Allocator::standard());
 140             session.postNotification(kNotificationDomainPCSC, kNotificationPCSCStateChange, CssmData());
 141         }
 142     } catch (const exception &e) {
 143         Syslog::error("An error '%s' occured while tracking token readers", e.what());
 144     }
 145 }
 146
 147 TokenCache& PCSCMonitor::tokenCache()
 148 {
 149         if (mTokenCache == NULL)
 150                 mTokenCache = new TokenCache(mCachePath.c_str());
 151         return *mTokenCache;
 152 }
 153
 154 //
 155 // Event notifier.
 156 // These events are sent by pcscd for our (sole) benefit.
 157 //
 158 void PCSCMonitor::notifyMe(Notification *message)
 159 {
 160 }
 161
 162 //
 163 // Timer action. Perform the initial PCSC subsystem initialization.
 164 // This runs (shortly) after securityd is fully functional and the
 165 // server loop has started.
 166 //
 167 void PCSCMonitor::action()
 168 {
 169     switch (mServiceLevel) {
 170         case forcedOff:
 171             secdebug("pcsc", "smartcard operation is FORCED OFF");
 172             break;
 173
 174         case externalDaemon:
 175             secdebug("pcsc", "using PCSC");
 176             startSoftTokens();
 177
 178             // Start PCSC reader watching thread.
 179             (new Watcher(server, tokenCache(), mReaders))->run();
 180             break;
 181     }
 182 }
 183
 184
 185 //
 186 // Software token support
 187 //
 188 void PCSCMonitor::startSoftTokens()
 189 {
 190         // scan for new ones
 191         CodeRepository<Bundle> candidates("Security/tokend", ".tokend", "TOKENDAEMONPATH", false);
 192         candidates.update();
 193         for (CodeRepository<Bundle>::iterator it = candidates.begin(); it != candidates.end(); ++it) {
 194                 if (CFTypeRef type = (*it)->infoPlistItem("TokendType"))
 195                         if (CFEqual(type, CFSTR("software")))
 196                                 loadSoftToken(*it);
 197         }
 198 }
 199
 200 void PCSCMonitor::loadSoftToken(Bundle *tokendBundle)
 201 {
 202         try {
 203                 string bundleName = tokendBundle->identifier();
 204
 205                 // prepare a virtual reader, removing any existing one (this would kill a previous tokend)
 206                 assert(mReaders.find(bundleName) == mReaders.end());    // not already present
 207                 RefPointer<Reader> reader = new Reader(tokenCache(), bundleName);
 208
 209                 // now launch the tokend
 210                 RefPointer<TokenDaemon> tokend = new TokenDaemon(tokendBundle,
 211                         reader->name(), reader->pcscState(), reader->cache);
 212
 213                 if (tokend->state() == ServerChild::dead) {     // ah well, this one's no good
 214                         secdebug("pcsc", "softtoken %s tokend launch failed", bundleName.c_str());
 215                         Syslog::notice("Software token %s failed to run", tokendBundle->canonicalPath().c_str());
 216                         return;
 217                 }
 218
 219                 // probe the (single) tokend
 220                 if (!tokend->probe()) {         // non comprende...
 221                         secdebug("pcsc", "softtoken %s probe failed", bundleName.c_str());
 222                         Syslog::notice("Software token %s refused operation", tokendBundle->canonicalPath().c_str());
 223                         return;
 224                 }
 225
 226                 // okay, this seems to work. Set it up
 227                 mReaders.insert(make_pair(reader->name(), reader));
 228                 reader->insertToken(tokend);
 229                 Syslog::notice("Software token %s activated", bundleName.c_str());
 230         } catch (...) {
 231                 secdebug("pcsc", "exception loading softtoken %s - continuing", tokendBundle->identifier().c_str());
 232         }
 233 }