OSX/authd/process.c

   1 /* Copyright (c) 2012-2013 Apple Inc. All Rights Reserved. */
   2
   3 #include "process.h"
   4 #include "server.h"
   5 #include "session.h"
   6 #include "debugging.h"
   7 #include "authd_private.h"
   8 #include "authtoken.h"
   9 #include "authutilities.h"
  10 #include "ccaudit.h"
  11
  12 #include <Security/SecCode.h>
  13 #include <Security/SecRequirement.h>
  14
  15 AUTHD_DEFINE_LOG
  16
  17 struct _process_s {
  18     __AUTH_BASE_STRUCT_HEADER__;
  19
  20     audit_info_s auditInfo;
  21
  22     session_t session;
  23
  24     CFMutableBagRef authTokens;
  25     dispatch_queue_t dispatch_queue;
  26
  27     CFMutableSetRef connections;
  28
  29     char code_url[PATH_MAX+1];
  30     char * code_identifier;
  31     CFDataRef code_requirement_data;
  32     SecRequirementRef code_requirement;
  33     CFDictionaryRef code_entitlements;
  34
  35     mach_port_t bootstrap;
  36
  37     bool appStoreSigned;
  38         bool firstPartySigned;
  39 };
  40
  41 static void
  42 _unregister_auth_tokens(const void *value, void *context)
  43 {
  44     auth_token_t auth = (auth_token_t)value;
  45     process_t proc = (process_t)context;
  46
  47     CFIndex count = auth_token_remove_process(auth, proc);
  48     if ((count == 0)  && auth_token_check_state(auth, auth_token_state_registered)) {
  49         server_unregister_auth_token(auth);
  50     }
  51 }
  52
  53 static void
  54 _destroy_zombie_tokens(process_t proc)
  55 {
  56     os_log_debug(AUTHD_LOG, "destroy zombies, %ld auth tokens", CFBagGetCount(proc->authTokens));
  57     _cf_bag_iterate(proc->authTokens, ^bool(CFTypeRef value) {
  58         auth_token_t auth = (auth_token_t)value;
  59         os_log_debug(AUTHD_LOG, "process:, creator=%i, zombie=%i, process_cout=%ld", auth_token_is_creator(auth, proc), auth_token_check_state(auth, auth_token_state_zombie), auth_token_get_process_count(auth));
  60         if (auth_token_is_creator(auth, proc) && auth_token_check_state(auth, auth_token_state_zombie) && (auth_token_get_process_count(auth) == 1)) {
  61             CFBagRemoveValue(proc->authTokens, auth);
  62         }
  63         return true;
  64     });
  65 }
  66
  67 static void
  68 _process_finalize(CFTypeRef value)
  69 {
  70     process_t proc = (process_t)value;
  71
  72     os_log_debug(AUTHD_LOG, "process deallocated");
  73
  74     dispatch_barrier_sync(proc->dispatch_queue, ^{
  75         CFBagApplyFunction(proc->authTokens, _unregister_auth_tokens, proc);
  76     });
  77
  78     session_remove_process(proc->session, proc);
  79
  80     dispatch_release(proc->dispatch_queue);
  81     CFReleaseNull(proc->authTokens);
  82     CFReleaseNull(proc->connections);
  83     CFReleaseNull(proc->session);
  84     CFReleaseNull(proc->code_requirement);
  85     CFReleaseNull(proc->code_requirement_data);
  86     CFReleaseNull(proc->code_entitlements);
  87     free_safe(proc->code_identifier);
  88     if (proc->bootstrap != MACH_PORT_NULL) {
  89         mach_port_deallocate(mach_task_self(), proc->bootstrap);
  90                 proc->bootstrap = MACH_PORT_NULL;
  91     }
  92 }
  93
  94 AUTH_TYPE_INSTANCE(process,
  95                    .init = NULL,
  96                    .copy = NULL,
  97                    .finalize = _process_finalize,
  98                    .equal = NULL,
  99                    .hash = NULL,
 100                    .copyFormattingDesc = NULL,
 101                    .copyDebugDesc = NULL
 102                    );
 103
 104 static CFTypeID process_get_type_id() {
 105     static CFTypeID type_id = _kCFRuntimeNotATypeID;
 106     static dispatch_once_t onceToken;
 107
 108     dispatch_once(&onceToken, ^{
 109         type_id = _CFRuntimeRegisterClass(&_auth_type_process);
 110     });
 111
 112     return type_id;
 113 }
 114
 115 process_t
 116 process_create(const audit_info_s * auditInfo, session_t session)
 117 {
 118     OSStatus status = errSecSuccess;
 119     process_t proc = NULL;
 120     CFDictionaryRef code_info = NULL;
 121     CFURLRef code_url = NULL;
 122     SecCodeRef codeRef = NULL;
 123
 124     require(session != NULL, done);
 125     require(auditInfo != NULL, done);
 126
 127     proc = (process_t)_CFRuntimeCreateInstance(kCFAllocatorDefault, process_get_type_id(), AUTH_CLASS_SIZE(process), NULL);
 128     require(proc != NULL, done);
 129
 130     proc->auditInfo = *auditInfo;
 131
 132     proc->session = (session_t)CFRetain(session);
 133
 134     proc->connections = CFSetCreateMutable(kCFAllocatorDefault, 0, NULL);
 135
 136     proc->authTokens = CFBagCreateMutable(kCFAllocatorDefault, 0, &kCFTypeBagCallBacks);
 137     check(proc->authTokens != NULL);
 138
 139     proc->dispatch_queue = dispatch_queue_create(NULL, DISPATCH_QUEUE_SERIAL);
 140     check(proc->dispatch_queue != NULL);
 141
 142     CFMutableDictionaryRef codeDict = CFDictionaryCreateMutable(kCFAllocatorDefault, 0, &kCFTypeDictionaryKeyCallBacks, &kCFTypeDictionaryValueCallBacks);
 143     CFDataRef auditToken = CFDataCreateWithBytesNoCopy(kCFAllocatorDefault, (UInt8 *)&auditInfo->opaqueToken, sizeof(auditInfo->opaqueToken), kCFAllocatorNull);
 144     if (auditToken) {
 145         CFDictionarySetValue(codeDict, kSecGuestAttributeAudit, auditToken);
 146         CFReleaseNull(auditToken);
 147     } else {
 148         CFReleaseSafe(codeDict);
 149         os_log_error(AUTHD_LOG, "process: PID %d failed to create audit token", proc->auditInfo.pid);
 150         CFReleaseNull(proc);
 151         goto done;
 152     }
 153     status = SecCodeCopyGuestWithAttributes(NULL, codeDict, kSecCSDefaultFlags, &codeRef);
 154     CFReleaseSafe(codeDict);
 155
 156     if (status) {
 157         os_log_error(AUTHD_LOG, "process: PID %d failed to create code ref %d", proc->auditInfo.pid, (int)status);
 158         CFReleaseNull(proc);
 159         goto done;
 160     }
 161
 162     status = SecCodeCopySigningInformation(codeRef, kSecCSRequirementInformation, &code_info);
 163     require_noerr_action(status, done, os_log_debug(AUTHD_LOG, "process: PID %d SecCodeCopySigningInformation failed with %d", proc->auditInfo.pid, (int)status));
 164
 165     CFTypeRef value = NULL;
 166     if (CFDictionaryGetValueIfPresent(code_info, kSecCodeInfoDesignatedRequirement, (const void**)&value)) {
 167         if (CFGetTypeID(value) == SecRequirementGetTypeID()) {
 168             SecRequirementCopyData((SecRequirementRef)value, kSecCSDefaultFlags, &proc->code_requirement_data);
 169             if (proc->code_requirement_data) {
 170                 SecRequirementCreateWithData(proc->code_requirement_data, kSecCSDefaultFlags, &proc->code_requirement);
 171             }
 172         }
 173         value = NULL;
 174     }
 175
 176     if (SecCodeCopyPath(codeRef, kSecCSDefaultFlags, &code_url) == errSecSuccess) {
 177         CFURLGetFileSystemRepresentation(code_url, true, (UInt8*)proc->code_url, sizeof(proc->code_url));
 178     }
 179
 180     if (CFDictionaryGetValueIfPresent(code_info, kSecCodeInfoIdentifier, &value)) {
 181         if (CFGetTypeID(value) == CFStringGetTypeID()) {
 182             proc->code_identifier = _copy_cf_string(value, NULL);
 183         }
 184         value = NULL;
 185     }
 186
 187     if (CFDictionaryGetValueIfPresent(code_info, kSecCodeInfoEntitlementsDict, &value)) {
 188         if (CFGetTypeID(value) == CFDictionaryGetTypeID()) {
 189             proc->code_entitlements = CFDictionaryCreateCopy(kCFAllocatorDefault, value);
 190         }
 191         value = NULL;
 192     }
 193
 194     // This is the clownfish supported way to check for a Mac App Store or B&I signed build
 195         // AppStore apps must have resource envelope 2. Check with spctl -a -t exec -vv <path>
 196     CFStringRef firstPartyRequirement = CFSTR("anchor apple");
 197         CFStringRef appStoreRequirement = CFSTR("anchor apple generic and certificate leaf[field.1.2.840.113635.100.6.1.9] exists");
 198     SecRequirementRef secRequirementRef = NULL;
 199     status = SecRequirementCreateWithString(firstPartyRequirement, kSecCSDefaultFlags, &secRequirementRef);
 200     if (status == errSecSuccess) {
 201         proc->firstPartySigned = process_verify_requirement(proc, codeRef, secRequirementRef);
 202                 CFReleaseNull(secRequirementRef);
 203     }
 204         status = SecRequirementCreateWithString(appStoreRequirement, kSecCSDefaultFlags, &secRequirementRef);
 205         if (status == errSecSuccess) {
 206                 proc->appStoreSigned = process_verify_requirement(proc, codeRef, secRequirementRef);
 207                 CFReleaseSafe(secRequirementRef);
 208         }
 209     os_log_debug(AUTHD_LOG, "process: PID %d created (sid=%i) %{public}s", proc->auditInfo.pid, proc->auditInfo.asid, proc->code_url);
 210
 211 done:
 212     CFReleaseSafe(code_info);
 213     CFReleaseSafe(code_url);
 214     CFReleaseSafe(codeRef);
 215     return proc;
 216 }
 217
 218 const void *
 219 process_get_key(process_t proc)
 220 {
 221     return &proc->auditInfo;
 222 }
 223
 224 uid_t
 225 process_get_uid(process_t proc)
 226 {
 227     assert(proc); // marked non-null
 228     return proc->auditInfo.euid;
 229 }
 230
 231 pid_t
 232 process_get_pid(process_t proc)
 233 {
 234     assert(proc); // marked non-null
 235     return proc->auditInfo.pid;
 236 }
 237
 238 int32_t process_get_generation(process_t proc)
 239 {
 240     assert(proc); // marked non-null
 241     return proc->auditInfo.tid;
 242 }
 243
 244 session_id_t
 245 process_get_session_id(process_t proc)
 246 {
 247     assert(proc); // marked non-null
 248     return proc->auditInfo.asid;
 249 }
 250
 251 session_t
 252 process_get_session(process_t proc)
 253 {
 254     assert(proc); // marked non-null
 255     return proc->session;
 256 }
 257
 258 const audit_info_s *
 259 process_get_audit_info(process_t proc)
 260 {
 261     return &proc->auditInfo;
 262 }
 263
 264 const char *
 265 process_get_code_url(process_t proc)
 266 {
 267     return proc->code_url;
 268 }
 269
 270 void
 271 process_add_auth_token(process_t proc, auth_token_t auth)
 272 {
 273     dispatch_sync(proc->dispatch_queue, ^{
 274         CFBagAddValue(proc->authTokens, auth);
 275         if (CFBagGetCountOfValue(proc->authTokens, auth) == 1) {
 276             auth_token_add_process(auth, proc);
 277         }
 278     });
 279 }
 280
 281 void
 282 process_remove_auth_token(process_t proc, auth_token_t auth, uint32_t flags)
 283 {
 284     dispatch_sync(proc->dispatch_queue, ^{
 285         bool destroy = false;
 286         bool creator = auth_token_is_creator(auth, proc);
 287         CFIndex count = auth_token_get_process_count(auth);
 288
 289         // if we are the last ones associated with this auth token or the caller passed in the kAuthorizationFlagDestroyRights
 290         // then we break the link between the process and auth token.  If another process holds a reference
 291         // then kAuthorizationFlagDestroyRights will only break the link and not destroy the auth token
 292         // <rdar://problem/14553640>
 293         if ((count == 1) ||
 294             (flags & kAuthorizationFlagDestroyRights))
 295         {
 296             destroy = true;
 297             goto done;
 298         }
 299
 300         // If we created this token and someone else is holding a reference to it
 301         // don't destroy the link until they have freed the authorization ref
 302         // instead set the zombie state on the auth_token
 303         if (creator) {
 304             if (CFBagGetCountOfValue(proc->authTokens, auth) == 1) {
 305                 auth_token_set_state(auth, auth_token_state_zombie);
 306             } else {
 307                 destroy = true;
 308             }
 309         } else {
 310             destroy = true;
 311         }
 312
 313     done:
 314         if (destroy) {
 315             CFBagRemoveValue(proc->authTokens, auth);
 316             if (!CFBagContainsValue(proc->authTokens, auth)) {
 317                 auth_token_remove_process(auth, proc);
 318
 319                 if ((count == 1) && auth_token_check_state(auth, auth_token_state_registered)) {
 320                     server_unregister_auth_token(auth);
 321                 }
 322             }
 323         }
 324
 325         // destroy all eligible zombies
 326         _destroy_zombie_tokens(proc);
 327     });
 328 }
 329
 330 auth_token_t
 331 process_find_copy_auth_token(process_t proc, const AuthorizationBlob * blob)
 332 {
 333     __block CFTypeRef auth = NULL;
 334     dispatch_sync(proc->dispatch_queue, ^{
 335         _cf_bag_iterate(proc->authTokens, ^bool(CFTypeRef value) {
 336             auth_token_t iter = (auth_token_t)value;
 337             if (memcmp(blob, auth_token_get_blob(iter), sizeof(AuthorizationBlob)) == 0) {
 338                 auth = iter;
 339                 CFRetain(auth);
 340                 return false;
 341             }
 342             return true;
 343         });
 344     });
 345     return (auth_token_t)auth;
 346 }
 347
 348 CFIndex
 349 process_get_auth_token_count(process_t proc)
 350 {
 351     __block CFIndex count = 0;
 352     dispatch_sync(proc->dispatch_queue, ^{
 353         count = CFBagGetCount(proc->authTokens);
 354     });
 355     return count;
 356 }
 357
 358 CFIndex
 359 process_add_connection(process_t proc, connection_t conn)
 360 {
 361     __block CFIndex count = 0;
 362     dispatch_sync(proc->dispatch_queue, ^{
 363         CFSetAddValue(proc->connections, conn);
 364         count = CFSetGetCount(proc->connections);
 365     });
 366     return count;
 367 }
 368
 369 CFIndex
 370 process_remove_connection(process_t proc, connection_t conn)
 371 {
 372     __block CFIndex count = 0;
 373     dispatch_sync(proc->dispatch_queue, ^{
 374         CFSetRemoveValue(proc->connections, conn);
 375         count = CFSetGetCount(proc->connections);
 376     });
 377     return count;
 378 }
 379
 380 CFIndex
 381 process_get_connection_count(process_t proc)
 382 {
 383     __block CFIndex count = 0;
 384     dispatch_sync(proc->dispatch_queue, ^{
 385         count = CFSetGetCount(proc->connections);
 386     });
 387     return count;
 388 }
 389
 390 CFTypeRef
 391 process_copy_entitlement_value(process_t proc, const char * entitlement)
 392 {
 393     CFTypeRef value = NULL;
 394     require(entitlement != NULL, done);
 395
 396     CFStringRef key = CFStringCreateWithCStringNoCopy(kCFAllocatorDefault, entitlement, kCFStringEncodingUTF8, kCFAllocatorNull);
 397     if (proc->code_entitlements && key && (CFDictionaryGetValueIfPresent(proc->code_entitlements, key, &value))) {
 398         CFRetainSafe(value);
 399     }
 400     CFReleaseSafe(key);
 401
 402 done:
 403     return value;
 404 }
 405
 406 bool
 407 process_has_entitlement(process_t proc, const char * entitlement)
 408 {
 409     bool entitled = false;
 410     require(entitlement != NULL, done);
 411
 412     CFStringRef key = CFStringCreateWithCStringNoCopy(kCFAllocatorDefault, entitlement, kCFStringEncodingUTF8, kCFAllocatorNull);
 413     CFTypeRef value = NULL;
 414     if (proc->code_entitlements && key && (CFDictionaryGetValueIfPresent(proc->code_entitlements, key, &value))) {
 415         if (CFGetTypeID(value) == CFBooleanGetTypeID()) {
 416             entitled = CFBooleanGetValue(value);
 417         }
 418     }
 419     CFReleaseSafe(key);
 420
 421 done:
 422     return entitled;
 423 }
 424
 425 bool
 426 process_has_entitlement_for_right(process_t proc, const char * right)
 427 {
 428     bool entitled = false;
 429     require(right != NULL, done);
 430
 431     CFTypeRef rights = NULL;
 432     if (proc->code_entitlements && CFDictionaryGetValueIfPresent(proc->code_entitlements, CFSTR("com.apple.private.AuthorizationServices"), &rights)) {
 433         if (CFGetTypeID(rights) == CFArrayGetTypeID()) {
 434             CFStringRef key = CFStringCreateWithCStringNoCopy(kCFAllocatorDefault, right, kCFStringEncodingUTF8, kCFAllocatorNull);
 435             require(key != NULL, done);
 436
 437             CFIndex count = CFArrayGetCount(rights);
 438             for (CFIndex i = 0; i < count; i++) {
 439                 if (CFEqual(CFArrayGetValueAtIndex(rights, i), key)) {
 440                     entitled = true;
 441                     break;
 442                 }
 443             }
 444             CFReleaseSafe(key);
 445         }
 446     }
 447
 448 done:
 449     return entitled;
 450 }
 451
 452 const char *
 453 process_get_identifier(process_t proc)
 454 {
 455     return proc->code_identifier;
 456 }
 457
 458 CFDataRef
 459 process_get_requirement_data(process_t proc)
 460 {
 461     return proc->code_requirement_data;
 462 }
 463
 464 SecRequirementRef
 465 process_get_requirement(process_t proc)
 466 {
 467     return proc->code_requirement;
 468 }
 469
 470 bool process_verify_requirement(process_t proc, SecCodeRef codeRef, SecRequirementRef requirment)
 471 {
 472     OSStatus status = SecCodeCheckValidity(codeRef, kSecCSDefaultFlags, requirment);
 473     if (status != errSecSuccess) {
 474         os_log_debug(AUTHD_LOG, "process: PID %d code requirement check failed (%d)", proc->auditInfo.pid, (int)status);
 475     }
 476     return (status == errSecSuccess);
 477 }
 478
 479 // Returns true if the process was signed by B&I or the Mac App Store
 480 bool process_apple_signed(process_t proc) {
 481     return (proc->firstPartySigned || proc->appStoreSigned);
 482 }
 483
 484 // Returns true if the process was signed by B&I
 485 bool process_firstparty_signed(process_t proc) {
 486         return proc->firstPartySigned;
 487 }
 488
 489 mach_port_t process_get_bootstrap(process_t proc)
 490 {
 491     return proc->bootstrap;
 492 }
 493
 494 bool process_set_bootstrap(process_t proc, mach_port_t bootstrap)
 495 {
 496     if (bootstrap != MACH_PORT_NULL) {
 497         if (proc->bootstrap != MACH_PORT_NULL) {
 498             mach_port_deallocate(mach_task_self(), proc->bootstrap);
 499         }
 500         proc->bootstrap = bootstrap;
 501         return true;
 502     }
 503     return false;
 504 }
 505