src/session.cpp

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  23
  24
  25 //
  26 // session - authentication session domains
  27 //
  28 // A Session is defined by a mach_init bootstrap dictionary. These dictionaries are
  29 // hierarchical and inherited, so they work well for characterization of processes
  30 // that "belong" together. (Of course, if your mach_init is broken, you're in bad shape.)
  31 //
  32 // Sessions are multi-threaded objects.
  33 //
  34 #include "session.h"
  35 #include "connection.h"
  36 #include "database.h"
  37 #include "server.h"
  38
  39
  40 //
  41 // The static session map
  42 //
  43 PortMap<Session> Session::mSessions;
  44
  45
  46 //
  47 // Create a Session object from initial parameters (create)
  48 //
  49 Session::Session(Bootstrap bootstrap, Port servicePort, SessionAttributeBits attrs)
  50     : mBootstrap(bootstrap), mServicePort(servicePort),
  51           mAttributes(attrs), mSecurityAgent(NULL), mAuthHost(NULL)
  52 {
  53     secdebug("SSsession", "%p CREATED: handle=0x%lx bootstrap=%d service=%d attrs=0x%lx",
  54         this, handle(), mBootstrap.port(), mServicePort.port(), mAttributes);
  55 }
  56
  57
  58 //
  59 // Destroy a Session
  60 //
  61 Session::~Session()
  62 {
  63     secdebug("SSsession", "%p DESTROYED: handle=0x%lx bootstrap=%d",
  64         this, handle(), mBootstrap.port());
  65 }
  66
  67
  68 //
  69 // Locate a session object by service port or (Session API) identifier
  70 //
  71 Session &Session::find(Port servicePort)
  72 {
  73     StLock<Mutex> _(mSessions);
  74         PortMap<Session>::const_iterator it = mSessions.find(servicePort);
  75         assert(it != mSessions.end());
  76         return *it->second;
  77 }
  78
  79 Session &Session::find(SecuritySessionId id)
  80 {
  81     switch (id) {
  82     case callerSecuritySession:
  83         return Server::session();
  84     default:
  85         return HandleObject::find<Session>(id, CSSMERR_CSSM_INVALID_ADDIN_HANDLE);
  86     }
  87 }
  88
  89
  90 //
  91 // Act on a death notification for a session's (sub)bootstrap port.
  92 // We may not destroy the Session outright here (due to processes that use it),
  93 // but we do clear out its accumulated wealth.
  94 //
  95 void Session::destroy(Port servPort)
  96 {
  97     // remove session from session map
  98     StLock<Mutex> _(mSessions);
  99     PortMap<Session>::iterator it = mSessions.find(servPort);
 100     assert(it != mSessions.end());
 101         RefPointer<Session> session = it->second;
 102     mSessions.erase(it);
 103         session->kill();
 104 }
 105
 106 void Session::kill()
 107 {
 108     StLock<Mutex> _(*this);
 109
 110         // release authorization host objects
 111         {
 112                 StLock<Mutex> _(mAuthHostLock);
 113                 mSecurityAgent = NULL;
 114                 mAuthHost = NULL;
 115         }
 116
 117     // invalidate shared credentials
 118     {
 119         StLock<Mutex> _(mCredsLock);
 120
 121         IFDEBUG(if (!mSessionCreds.empty())
 122             secdebug("SSauth", "session %p clearing %d shared credentials",
 123                 this, int(mSessionCreds.size())));
 124         for (CredentialSet::iterator it = mSessionCreds.begin(); it != mSessionCreds.end(); it++)
 125             (*it)->invalidate();
 126     }
 127
 128         // base kill processing
 129         PerSession::kill();
 130 }
 131
 132
 133 //
 134 // On system sleep, call sleepProcessing on all DbCommons of all Sessions
 135 //
 136 void Session::processSystemSleep()
 137 {
 138         StLock<Mutex> _(mSessions);
 139         for (PortMap<Session>::const_iterator it = mSessions.begin(); it != mSessions.end(); it++)
 140                 it->second->allReferences(&DbCommon::sleepProcessing);
 141 }
 142
 143
 144 //
 145 // On "lockAll", call sleepProcessing on all DbCommons of this session (only)
 146 //
 147 void Session::processLockAll()
 148 {
 149         allReferences(&DbCommon::lockProcessing);
 150 }
 151
 152
 153 //
 154 // The root session inherits the startup bootstrap and service port
 155 //
 156 RootSession::RootSession(Server &server, SessionAttributeBits attrs)
 157     : Session(Bootstrap(), server.primaryServicePort(),
 158                 sessionIsRoot | sessionWasInitialized | attrs)
 159 {
 160         parent(server);         // the Server is our parent
 161         ref();                          // eternalize
 162
 163     // self-install (no thread safety issues here)
 164         mSessions[mServicePort] = this;
 165 }
 166
 167 uid_t RootSession::originatorUid() const
 168 {
 169         return 0;       // it's root, obviously
 170 }
 171
 172 CFDataRef RootSession::copyUserPrefs()
 173 {
 174         return NULL;
 175 }
 176
 177 //
 178 // Dynamic sessions use the given bootstrap and re-register in it
 179 //
 180 DynamicSession::DynamicSession(TaskPort taskPort)
 181         : ReceivePort(Server::active().bootstrapName(), taskPort.bootstrap()),
 182           Session(taskPort.bootstrap(), *this),
 183           mOriginatorTask(taskPort), mHaveOriginatorUid(false)
 184 {
 185         // link to Server as the global nexus in the object mesh
 186         parent(Server::active());
 187
 188         // tell the server to listen to our port
 189         Server::active().add(*this);
 190
 191         // register for port notifications
 192     Server::active().notifyIfDead(bootstrapPort());     //@@@??? still needed?
 193         Server::active().notifyIfUnused(*this);
 194
 195         // self-register
 196         StLock<Mutex> _(mSessions);
 197         assert(!mSessions[*this]);  // can't be registered already (we just made it)
 198         mSessions[*this] = this;
 199
 200         secdebug("SSsession", "%p dynamic session originator=%d (pid=%d)",
 201                 this, mOriginatorTask.port(), taskPort.pid());
 202 }
 203
 204 DynamicSession::~DynamicSession()
 205 {
 206         // remove our service port from the server
 207         Server::active().remove(*this);
 208 }
 209
 210
 211 void DynamicSession::kill()
 212 {
 213         StLock<Mutex> _(*this);
 214         mBootstrap.destroy();           // release our bootstrap port
 215         Session::kill();                        // continue with parent kill
 216 }
 217
 218
 219 //
 220 // Set up a DynamicSession.
 221 // This call must be made from a process within the session, and it must be the first
 222 // such process to make the call.
 223 //
 224 void DynamicSession::setupAttributes(SessionCreationFlags flags, SessionAttributeBits attrs)
 225 {
 226         StLock<Mutex> _(*this);
 227     secdebug("SSsession", "%p setup flags=0x%lx attrs=0x%lx", this, flags, attrs);
 228     if (attrs & ~settableAttributes)
 229         MacOSError::throwMe(errSessionInvalidAttributes);
 230         checkOriginator();
 231     if (attribute(sessionWasInitialized))
 232         MacOSError::throwMe(errSessionAuthorizationDenied);
 233     setAttributes(attrs | sessionWasInitialized);
 234 }
 235
 236
 237 //
 238 // Check whether the calling process is the session originator.
 239 // If it's not, throw.
 240 //
 241 void DynamicSession::checkOriginator()
 242 {
 243         if (mOriginatorTask != Server::process().taskPort())
 244                 MacOSError::throwMe(errSessionAuthorizationDenied);
 245 }
 246
 247
 248 //
 249 // The "originator uid" is a uid value that can be provided by the session originator
 250 // and retrieved by anyone. Securityd places no semantic meaning on this value.
 251 //
 252 uid_t DynamicSession::originatorUid() const
 253 {
 254         if (mHaveOriginatorUid)
 255                 return mOriginatorUid;
 256         else
 257                 MacOSError::throwMe(errSessionValueNotSet);
 258 }
 259
 260
 261 void DynamicSession::originatorUid(uid_t uid)
 262 {
 263         checkOriginator();
 264         if (mHaveOriginatorUid)         // must not re-set this
 265                 MacOSError::throwMe(errSessionAuthorizationDenied);
 266         mHaveOriginatorUid = true;
 267         mOriginatorUid = uid;
 268         secdebug("SSsession", "%p session uid set to %d", this, uid);
 269 }
 270
 271
 272 //
 273 // Authorization operations
 274 //
 275 OSStatus Session::authCreate(const AuthItemSet &rights,
 276         const AuthItemSet &environment,
 277         AuthorizationFlags flags,
 278         AuthorizationBlob &newHandle,
 279         const audit_token_t &auditToken)
 280 {
 281         // invoke the authorization computation engine
 282         CredentialSet resultCreds;
 283
 284         // this will acquire the object lock, so we delay acquiring it (@@@ no longer needed)
 285         auto_ptr<AuthorizationToken> auth(new AuthorizationToken(*this, resultCreds, auditToken));
 286
 287     // Make a copy of the mSessionCreds
 288     CredentialSet sessionCreds;
 289     {
 290         StLock<Mutex> _(mCredsLock);
 291         sessionCreds = mSessionCreds;
 292     }
 293
 294         AuthItemSet outRights;
 295         OSStatus result = Server::authority().authorize(rights, environment, flags,
 296         &sessionCreds, &resultCreds, outRights, *auth);
 297         newHandle = auth->handle();
 298
 299     // merge resulting creds into shared pool
 300     if ((flags & kAuthorizationFlagExtendRights) &&
 301         !(flags & kAuthorizationFlagDestroyRights))
 302     {
 303         StLock<Mutex> _(mCredsLock);
 304         mergeCredentials(resultCreds);
 305         auth->mergeCredentials(resultCreds);
 306     }
 307
 308         // Make sure that this isn't done until the auth(AuthorizationToken) is guaranteed to
 309         // not be destroyed anymore since it's destructor asserts it has no processes
 310         Server::process().addAuthorization(auth.get());
 311         auth.release();
 312         return result;
 313 }
 314
 315 void Session::authFree(const AuthorizationBlob &authBlob, AuthorizationFlags flags)
 316 {
 317     AuthorizationToken::Deleter deleter(authBlob);
 318     AuthorizationToken &auth = deleter;
 319         Process &process = Server::process();
 320         process.checkAuthorization(&auth);
 321
 322         if (flags & kAuthorizationFlagDestroyRights) {
 323                 // explicitly invalidate all shared credentials and remove them from the session
 324                 for (CredentialSet::const_iterator it = auth.begin(); it != auth.end(); it++)
 325                         if ((*it)->isShared())
 326                                 (*it)->invalidate();
 327         }
 328
 329         // now get rid of the authorization itself
 330         if (process.removeAuthorization(&auth))
 331         deleter.remove();
 332 }
 333
 334 OSStatus Session::authGetRights(const AuthorizationBlob &authBlob,
 335         const AuthItemSet &rights, const AuthItemSet &environment,
 336         AuthorizationFlags flags,
 337         AuthItemSet &grantedRights)
 338 {
 339     CredentialSet resultCreds;
 340     AuthorizationToken &auth = authorization(authBlob);
 341     CredentialSet effective;
 342     {
 343         StLock<Mutex> _(mCredsLock);
 344         effective        = auth.effectiveCreds();
 345     }
 346         OSStatus result = Server::authority().authorize(rights, environment, flags,
 347         &effective, &resultCreds, grantedRights, auth);
 348
 349         // merge resulting creds into shared pool
 350         if ((flags & kAuthorizationFlagExtendRights) && !(flags & kAuthorizationFlagDestroyRights))
 351     {
 352         StLock<Mutex> _(mCredsLock);
 353         mergeCredentials(resultCreds);
 354         auth.mergeCredentials(resultCreds);
 355         }
 356
 357         secdebug("SSauth", "Authorization %p copyRights asked for %d got %d",
 358                 &authorization(authBlob), int(rights.size()), int(grantedRights.size()));
 359         return result;
 360 }
 361
 362 OSStatus Session::authGetInfo(const AuthorizationBlob &authBlob,
 363         const char *tag,
 364         AuthItemSet &contextInfo)
 365 {
 366         AuthorizationToken &auth = authorization(authBlob);
 367         secdebug("SSauth", "Authorization %p get-info", &auth);
 368         contextInfo = auth.infoSet(tag);
 369     return noErr;
 370 }
 371
 372 OSStatus Session::authExternalize(const AuthorizationBlob &authBlob,
 373         AuthorizationExternalForm &extForm)
 374 {
 375         const AuthorizationToken &auth = authorization(authBlob);
 376         StLock<Mutex> _(*this);
 377         if (auth.mayExternalize(Server::process())) {
 378                 memset(&extForm, 0, sizeof(extForm));
 379         AuthorizationExternalBlob &extBlob =
 380             reinterpret_cast<AuthorizationExternalBlob &>(extForm);
 381         extBlob.blob = auth.handle();
 382         extBlob.session = bootstrapPort();
 383                 secdebug("SSauth", "Authorization %p externalized", &auth);
 384                 return noErr;
 385         } else
 386                 return errAuthorizationExternalizeNotAllowed;
 387 }
 388
 389 OSStatus Session::authInternalize(const AuthorizationExternalForm &extForm,
 390         AuthorizationBlob &authBlob)
 391 {
 392         // interpret the external form
 393     const AuthorizationExternalBlob &extBlob =
 394         reinterpret_cast<const AuthorizationExternalBlob &>(extForm);
 395
 396     // locate source authorization
 397     AuthorizationToken &sourceAuth = AuthorizationToken::find(extBlob.blob);
 398
 399         // check for permission and do it
 400         if (sourceAuth.mayInternalize(Server::process(), true)) {
 401                 StLock<Mutex> _(*this);
 402                 authBlob = extBlob.blob;
 403         Server::process().addAuthorization(&sourceAuth);
 404         secdebug("SSauth", "Authorization %p internalized", &sourceAuth);
 405                 return noErr;
 406         } else
 407                 return errAuthorizationInternalizeNotAllowed;
 408 }
 409
 410
 411 //
 412 // The default session setup operation always fails.
 413 // Subclasses can override this to support session setup calls.
 414 //
 415 void Session::setupAttributes(SessionCreationFlags flags, SessionAttributeBits attrs)
 416 {
 417         MacOSError::throwMe(errSessionAuthorizationDenied);
 418 }
 419
 420
 421 //
 422 // Authorization database I/O
 423 //
 424 OSStatus Session::authorizationdbGet(AuthorizationString inRightName, CFDictionaryRef *rightDict)
 425 {
 426         string rightName(inRightName);
 427         return Server::authority().getRule(rightName, rightDict);
 428 }
 429
 430
 431 OSStatus Session::authorizationdbSet(const AuthorizationBlob &authBlob, AuthorizationString inRightName, CFDictionaryRef rightDict)
 432 {
 433         CredentialSet resultCreds;
 434     AuthorizationToken &auth = authorization(authBlob);
 435     CredentialSet effective;
 436
 437     {
 438         StLock<Mutex> _(mCredsLock);
 439         effective        = auth.effectiveCreds();
 440     }
 441
 442         OSStatus result = Server::authority().setRule(inRightName, rightDict, &effective, &resultCreds, auth);
 443
 444     {
 445         StLock<Mutex> _(mCredsLock);
 446         mergeCredentials(resultCreds);
 447         auth.mergeCredentials(resultCreds);
 448         }
 449
 450         secdebug("SSauth", "Authorization %p authorizationdbSet %s (result=%ld)",
 451                 &authorization(authBlob), inRightName, result);
 452         return result;
 453 }
 454
 455
 456 OSStatus Session::authorizationdbRemove(const AuthorizationBlob &authBlob, AuthorizationString inRightName)
 457 {
 458         CredentialSet resultCreds;
 459     AuthorizationToken &auth = authorization(authBlob);
 460     CredentialSet effective;
 461
 462     {
 463         StLock<Mutex> _(mCredsLock);
 464         effective        = auth.effectiveCreds();
 465     }
 466
 467         OSStatus result = Server::authority().removeRule(inRightName, &effective, &resultCreds, auth);
 468
 469     {
 470         StLock<Mutex> _(mCredsLock);
 471         mergeCredentials(resultCreds);
 472         auth.mergeCredentials(resultCreds);
 473         }
 474
 475         secdebug("SSauth", "Authorization %p authorizationdbRemove %s (result=%ld)",
 476                 &authorization(authBlob), inRightName, result);
 477         return result;
 478 }
 479
 480
 481 //
 482 // Merge a set of credentials into the shared-session credential pool
 483 //
 484 // must hold mCredsLock
 485 void Session::mergeCredentials(CredentialSet &creds)
 486 {
 487     secdebug("SSsession", "%p merge creds @%p", this, &creds);
 488         for (CredentialSet::const_iterator it = creds.begin(); it != creds.end(); it++)
 489                 if (((*it)->isShared() && (*it)->isValid())) {
 490                         CredentialSet::iterator old = mSessionCreds.find(*it);
 491                         if (old == mSessionCreds.end()) {
 492                                 mSessionCreds.insert(*it);
 493             } else {
 494                 // replace "new" with "old" in input set to retain synchronization
 495                                 (*old)->merge(**it);
 496                 creds.erase(it);
 497                 creds.insert(*old);
 498             }
 499                 }
 500 }
 501
 502
 503 //
 504 // Locate an AuthorizationToken given a blob
 505 //
 506 AuthorizationToken &Session::authorization(const AuthorizationBlob &blob)
 507 {
 508     AuthorizationToken &auth = AuthorizationToken::find(blob);
 509         Server::process().checkAuthorization(&auth);
 510         return auth;
 511 }
 512
 513 RefPointer<AuthHostInstance>
 514 Session::authhost(const AuthHostType hostType, const bool restart)
 515 {
 516         StLock<Mutex> _(mAuthHostLock);
 517
 518         if (hostType == privilegedAuthHost)
 519         {
 520                 if (restart || !mAuthHost || (mAuthHost->state() != Security::UnixPlusPlus::Child::alive))
 521                 {
 522                         if (mAuthHost)
 523                                 PerSession::kill(*mAuthHost);
 524                         mAuthHost = new AuthHostInstance(*this, hostType);
 525                 }
 526                 return mAuthHost;
 527         }
 528         else /* if (hostType == securityAgent) */
 529         {
 530                 if (restart || !mSecurityAgent || (mSecurityAgent->state() != Security::UnixPlusPlus::Child::alive))
 531                 {
 532                         if (mSecurityAgent)
 533                                 PerSession::kill(*mSecurityAgent);
 534                         mSecurityAgent = new AuthHostInstance(*this, hostType);
 535                 }
 536                 return mSecurityAgent;
 537         }
 538 }
 539
 540 void DynamicSession::setUserPrefs(CFDataRef userPrefsDict)
 541 {
 542         checkOriginator();
 543         StLock<Mutex> _(*this);
 544         mSessionAgentPrefs = userPrefsDict;
 545 }
 546
 547 CFDataRef DynamicSession::copyUserPrefs()
 548 {
 549         StLock<Mutex> _(*this);
 550         if (mSessionAgentPrefs)
 551                 CFRetain(mSessionAgentPrefs);
 552         return mSessionAgentPrefs;
 553 }
 554
 555
 556 //
 557 // Debug dumping
 558 //
 559 #if defined(DEBUGDUMP)
 560
 561 void Session::dumpNode()
 562 {
 563         PerSession::dumpNode();
 564         Debug::dump(" boot=%d service=%d attrs=0x%lx authhost=%p securityagent=%p",
 565                 mBootstrap.port(), mServicePort.port(), mAttributes, mAuthHost, mSecurityAgent);
 566 }
 567
 568 #endif //DEBUGDUMP