OSX/libsecurity_codesigning/lib/xpcengine.cpp

   1 /*
   2  * Copyright (c) 2011-2016 Apple Inc. All Rights Reserved.
   3  *
   4  * @APPLE_LICENSE_HEADER_START@
   5  *
   6  * This file contains Original Code and/or Modifications of Original Code
   7  * as defined in and that are subject to the Apple Public Source License
   8  * Version 2.0 (the 'License'). You may not use this file except in
   9  * compliance with the License. Please obtain a copy of the License at
  10  * http://www.opensource.apple.com/apsl/ and read it before using this
  11  * file.
  12  *
  13  * The Original Code and all software distributed under the License are
  14  * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
  15  * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
  16  * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
  17  * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
  18  * Please see the License for the specific language governing rights and
  19  * limitations under the License.
  20  *
  21  * @APPLE_LICENSE_HEADER_END@
  22  */
  23 #include "xpcengine.h"
  24 #include <xpc/connection.h>
  25 #include <syslog.h>
  26 #include <CoreFoundation/CoreFoundation.h>
  27 #include <security_utilities/cfutilities.h>
  28 #include <security_utilities/logging.h>
  29 #include <security_utilities/cfmunge.h>
  30
  31 #include <map>
  32
  33 namespace Security {
  34 namespace CodeSigning {
  35
  36
  37 static void doProgress(xpc_object_t msg);
  38
  39
  40 static const char serviceName[] = "com.apple.security.syspolicy";
  41
  42
  43 static dispatch_once_t dispatchInit;            // one-time init marker
  44 static xpc_connection_t service;                        // connection to spd
  45 static dispatch_queue_t queue;                          // dispatch queue for service
  46
  47 static map<uint64_t, SecAssessmentFeedback> *feedbackBlocks;
  48
  49 static void init()
  50 {
  51         dispatch_once(&dispatchInit, ^void(void) {
  52                 feedbackBlocks = new map<uint64_t, SecAssessmentFeedback>;
  53                 const char *name = serviceName;
  54                 if (const char *env = getenv("SYSPOLICYNAME"))
  55                         name = env;
  56                 queue = dispatch_queue_create("spd-client", DISPATCH_QUEUE_SERIAL);
  57                 service = xpc_connection_create_mach_service(name, queue, XPC_CONNECTION_MACH_SERVICE_PRIVILEGED);
  58                 xpc_connection_set_event_handler(service, ^(xpc_object_t msg) {
  59                         if (xpc_get_type(msg) == XPC_TYPE_DICTIONARY) {
  60                                 const char *function = xpc_dictionary_get_string(msg, "function");
  61                                 if (strcmp(function, "progress") == 0) {
  62                                         try {
  63                                                 doProgress(msg);
  64                                         } catch (...) {
  65                                                 Syslog::error("Discarding progress handler exception");
  66                                         }
  67                                 }
  68                         }
  69                 });
  70                 xpc_connection_resume(service);
  71         });
  72 }
  73
  74
  75 //
  76 // Your standard XPC client-side machinery
  77 //
  78 class Message {
  79 public:
  80         xpc_object_t obj;
  81
  82         Message(const char *function)
  83         {
  84                 init();
  85                 obj = xpc_dictionary_create(NULL, NULL, 0);
  86                 xpc_dictionary_set_string(obj, "function", function);
  87         }
  88         ~Message()
  89         {
  90                 if (obj)
  91                         xpc_release(obj);
  92         }
  93         operator xpc_object_t () { return obj; }
  94
  95         void send()
  96         {
  97                 xpc_object_t reply = xpc_connection_send_message_with_reply_sync(service, obj);
  98                 xpc_release(obj);
  99                 obj = NULL;
 100                 xpc_type_t type = xpc_get_type(reply);
 101                 if (type == XPC_TYPE_DICTIONARY) {
 102                         obj = reply;
 103                         if (int64_t error = xpc_dictionary_get_int64(obj, "error"))
 104                                 MacOSError::throwMe((int)error);
 105                 } else if (type == XPC_TYPE_ERROR) {
 106                         const char *s = xpc_copy_description(reply);
 107                         printf("Error returned: %s\n", s);
 108             Syslog::notice("code signing internal problem: unexpected error from xpc: %s", s);
 109                         free((char*)s);
 110             MacOSError::throwMe(errSecCSInternalError);
 111                 } else {
 112                         const char *s = xpc_copy_description(reply);
 113                         printf("Unexpected type of return object: %s\n", s);
 114                         free((char*)s);
 115                 }
 116         }
 117 };
 118
 119
 120
 121 static void copyCFDictionary(const void *key, const void *value, void *ctx)
 122 {
 123         CFMutableDictionaryRef target = CFMutableDictionaryRef(ctx);
 124         if (CFGetTypeID(value) == CFURLGetTypeID()) {
 125                 CFRef<CFStringRef> path = CFURLCopyFileSystemPath(CFURLRef(value), kCFURLPOSIXPathStyle);
 126                 CFDictionaryAddValue(target, key, path);
 127         } else if (!CFEqual(key, kSecAssessmentContextKeyFeedback)) {
 128                 CFDictionaryAddValue(target, key, value);
 129         }
 130 }
 131
 132
 133 static bool precheckAccess(CFURLRef path, CFDictionaryRef context)
 134 {
 135         CFTypeRef type = CFDictionaryGetValue(context, kSecAssessmentContextKeyOperation);
 136         if (type == NULL || CFEqual(type, kSecAssessmentOperationTypeExecute)) {
 137                 CFRef<SecStaticCodeRef> code;
 138                 OSStatus rc = SecStaticCodeCreateWithPath(path, kSecCSDefaultFlags, &code.aref());
 139         if (rc == errSecCSBadBundleFormat)  // work around <rdar://problem/26075034>
 140             return false;
 141                 CFRef<CFURLRef> exec;
 142                 MacOSError::check(SecCodeCopyPath(code, kSecCSDefaultFlags, &exec.aref()));
 143                 UnixError::check(::access(cfString(exec).c_str(), R_OK));
 144         } else {
 145                 UnixError::check(access(cfString(path).c_str(), R_OK));
 146         }
 147     return true;
 148 }
 149
 150
 151 void xpcEngineAssess(CFURLRef path, SecAssessmentFlags flags, CFDictionaryRef context, CFMutableDictionaryRef result)
 152 {
 153         precheckAccess(path, context);
 154         Message msg("assess");
 155         xpc_dictionary_set_string(msg, "path", cfString(path).c_str());
 156         xpc_dictionary_set_uint64(msg, "flags", flags);
 157         CFRef<CFMutableDictionaryRef> ctx = makeCFMutableDictionary();
 158         if (context) {
 159                 CFDictionaryApplyFunction(context, copyCFDictionary, ctx);
 160         }
 161
 162         SecAssessmentFeedback feedback = (SecAssessmentFeedback)CFDictionaryGetValue(context, kSecAssessmentContextKeyFeedback);
 163
 164         /* Map the feedback block to a random number for tracking, because we don't want
 165          * to send over a pointer. */
 166         uint64_t __block feedbackId = 0;
 167         if (feedback) {
 168                 dispatch_sync(queue, ^{
 169                         bool added = false;
 170                         while (!added) {
 171                                 /* Simple sequence number would probably be sufficient,
 172                                  * but making the id unpredictable is also cheap enough here. */
 173                                 arc4random_buf(&feedbackId, sizeof(uint64_t));
 174                                 if ((*feedbackBlocks)[feedbackId] == NULL /* extremely certain */) {
 175                                         (*feedbackBlocks)[feedbackId] = feedback;
 176                                         added = true;
 177                                 }
 178                         }
 179                 });
 180                 CFDictionaryAddValue(ctx, kSecAssessmentContextKeyFeedback, CFTempNumber(feedbackId));
 181         }
 182
 183         CFRef<CFDataRef> contextData = makeCFData(CFDictionaryRef(ctx));
 184         xpc_dictionary_set_data(msg, "context", CFDataGetBytePtr(contextData), CFDataGetLength(contextData));
 185
 186         msg.send();
 187
 188         /* Done, feedback block won't be called anymore,
 189          * so remove the feedback mapping from the global map. */
 190         if (feedback) {
 191                 dispatch_sync(queue, ^{
 192                         feedbackBlocks->erase(feedbackId);
 193                 });
 194         }
 195
 196         if (int64_t error = xpc_dictionary_get_int64(msg, "error"))
 197                 MacOSError::throwMe((int)error);
 198
 199         size_t resultLength;
 200         const void *resultData = xpc_dictionary_get_data(msg, "result", &resultLength);
 201         CFRef<CFDictionaryRef> resultDict = makeCFDictionaryFrom(resultData, resultLength);
 202         CFDictionaryApplyFunction(resultDict, copyCFDictionary, result);
 203         CFDictionaryAddValue(result, CFSTR("assessment:remote"), kCFBooleanTrue);
 204 }
 205
 206 static void doProgress(xpc_object_t msg)
 207 {
 208         uint64_t current = xpc_dictionary_get_uint64(msg, "current");
 209         uint64_t total = xpc_dictionary_get_uint64(msg, "total");
 210         uint64_t ref = xpc_dictionary_get_uint64(msg, "ref");
 211         const char *token = xpc_dictionary_get_string(msg, "token");
 212
 213         SecAssessmentFeedback feedback = NULL;
 214
 215         // doProgress is called on the queue, so no dispatch_sync here.
 216         try {
 217                 feedback = feedbackBlocks->at(ref);
 218         } catch (std::out_of_range) {
 219                 // Indicates that syspolicyd gave us something it shouldn't have.
 220                 Syslog::error("no feedback block registered with ID %lld", ref);
 221                 MacOSError::throwMe(errSecCSInternalError);
 222         }
 223
 224         CFTemp<CFDictionaryRef> info("{current=%d,total=%d}", current, total);
 225         Boolean proceed = feedback(kSecAssessmentFeedbackProgress, info);
 226         if (!proceed) {
 227                 xpc_connection_t connection = xpc_dictionary_get_remote_connection(msg);
 228                 xpc_object_t cancelRequest = xpc_dictionary_create(NULL, NULL, 0);
 229                 xpc_dictionary_set_string(cancelRequest, "function", "cancel");
 230                 xpc_dictionary_set_string(cancelRequest, "token", token);
 231                 xpc_connection_send_message(connection, cancelRequest);
 232                 xpc_release(cancelRequest);
 233         }
 234 }
 235
 236
 237 CFDictionaryRef xpcEngineUpdate(CFTypeRef target, SecAssessmentFlags flags, CFDictionaryRef context)
 238 {
 239         Message msg("update");
 240         // target can be NULL, a CFURLRef, a SecRequirementRef, or a CFNumberRef
 241         if (target) {
 242                 if (CFGetTypeID(target) == CFNumberGetTypeID())
 243                         xpc_dictionary_set_uint64(msg, "rule", cfNumber<int64_t>(CFNumberRef(target)));
 244                 else if (CFGetTypeID(target) == CFURLGetTypeID()) {
 245                         bool good = precheckAccess(CFURLRef(target), context);
 246             if (!good)      // work around <rdar://problem/26075034>
 247                 return makeCFDictionary(0); // pretend this worked
 248                         xpc_dictionary_set_string(msg, "url", cfString(CFURLRef(target)).c_str());
 249                 } else if (CFGetTypeID(target) == SecRequirementGetTypeID()) {
 250                         CFRef<CFDataRef> data;
 251                         MacOSError::check(SecRequirementCopyData(SecRequirementRef(target), kSecCSDefaultFlags, &data.aref()));
 252                         xpc_dictionary_set_data(msg, "requirement", CFDataGetBytePtr(data), CFDataGetLength(data));
 253                 } else
 254                         MacOSError::throwMe(errSecCSInvalidObjectRef);
 255         }
 256         xpc_dictionary_set_uint64(msg, "flags", flags);
 257         CFRef<CFMutableDictionaryRef> ctx = makeCFMutableDictionary();
 258         if (context)
 259                 CFDictionaryApplyFunction(context, copyCFDictionary, ctx);
 260         AuthorizationRef localAuthorization = NULL;
 261         if (CFDictionaryGetValue(ctx, kSecAssessmentUpdateKeyAuthorization) == NULL) {  // no caller-provided authorization
 262                 MacOSError::check(AuthorizationCreate(NULL, NULL, kAuthorizationFlagDefaults, &localAuthorization));
 263                 AuthorizationExternalForm extForm;
 264                 MacOSError::check(AuthorizationMakeExternalForm(localAuthorization, &extForm));
 265                 CFDictionaryAddValue(ctx, kSecAssessmentUpdateKeyAuthorization, CFTempData(&extForm, sizeof(extForm)));
 266         }
 267         CFRef<CFDataRef> contextData = makeCFData(CFDictionaryRef(ctx));
 268         xpc_dictionary_set_data(msg, "context", CFDataGetBytePtr(contextData), CFDataGetLength(contextData));
 269
 270         msg.send();
 271
 272         if (localAuthorization) {
 273                 AuthorizationFree(localAuthorization, kAuthorizationFlagDefaults);
 274         }
 275
 276         if (int64_t error = xpc_dictionary_get_int64(msg, "error")) {
 277                 MacOSError::throwMe((int)error);
 278         }
 279
 280         size_t resultLength;
 281         const void *resultData = xpc_dictionary_get_data(msg, "result", &resultLength);
 282         return makeCFDictionaryFrom(resultData, resultLength);
 283 }
 284
 285
 286 bool xpcEngineControl(const char *control)
 287 {
 288         Message msg("control");
 289         xpc_dictionary_set_string(msg, "control", control);
 290         msg.send();
 291         return true;
 292 }
 293
 294
 295 void xpcEngineRecord(CFDictionaryRef info)
 296 {
 297         Message msg("record");
 298         CFRef<CFDataRef> infoData = makeCFData(CFDictionaryRef(info));
 299         xpc_dictionary_set_data(msg, "info", CFDataGetBytePtr(infoData), CFDataGetLength(infoData));
 300
 301         msg.send();
 302 }
 303
 304 void xpcEngineCheckDevID(CFBooleanRef* result)
 305 {
 306     Message msg("check-dev-id");
 307
 308     msg.send();
 309
 310     if (int64_t error = xpc_dictionary_get_int64(msg, "error")) {
 311         MacOSError::throwMe((int)error);
 312     }
 313
 314     *result = xpc_dictionary_get_bool(msg,"result") ? kCFBooleanTrue : kCFBooleanFalse;
 315 }
 316
 317 void xpcEngineCheckNotarized(CFBooleanRef* result)
 318 {
 319         Message msg("check-notarized");
 320
 321         msg.send();
 322
 323         if (int64_t error = xpc_dictionary_get_int64(msg, "error")) {
 324                 MacOSError::throwMe((int)error);
 325         }
 326
 327         *result = xpc_dictionary_get_bool(msg,"result") ? kCFBooleanTrue : kCFBooleanFalse;
 328 }
 329
 330 void xpcEngineTicketRegister(CFDataRef ticketData)
 331 {
 332         Message msg("ticket-register");
 333         xpc_dictionary_set_data(msg, "ticketData", CFDataGetBytePtr(ticketData), CFDataGetLength(ticketData));
 334
 335         msg.send();
 336
 337         if (int64_t error = xpc_dictionary_get_int64(msg, "error")) {
 338                 MacOSError::throwMe((int)error);
 339         }
 340 }
 341
 342 void xpcEngineTicketLookup(CFDataRef hashData, SecCSDigestAlgorithm hashType, SecAssessmentTicketFlags flags, double *date)
 343 {
 344         Message msg("ticket-lookup");
 345         xpc_dictionary_set_data(msg, "hashData", CFDataGetBytePtr(hashData), CFDataGetLength(hashData));
 346         xpc_dictionary_set_uint64(msg, "hashType", hashType);
 347         xpc_dictionary_set_uint64(msg, "flags", flags);
 348
 349         msg.send();
 350
 351         if (int64_t error = xpc_dictionary_get_int64(msg, "error")) {
 352                 MacOSError::throwMe((int)error);
 353         }
 354
 355         double local_date = xpc_dictionary_get_double(msg, "date");
 356         if (date && !isnan(local_date)) {
 357                 *date = local_date;
 358         }
 359 }
 360
 361 void xpcEngineLegacyCheck(CFDataRef hashData, SecCSDigestAlgorithm hashType, CFStringRef teamID)
 362 {
 363         Message msg("legacy-check");
 364         xpc_dictionary_set_data(msg, "hashData", CFDataGetBytePtr(hashData), CFDataGetLength(hashData));
 365         xpc_dictionary_set_uint64(msg, "hashType", hashType);
 366
 367         // There may not be a team id, so just leave it off if there isn't since xpc_dictionary_set_string
 368         // will return a NULL if the value isn't provided.
 369         if (teamID) {
 370                 xpc_dictionary_set_string(msg, "teamID", CFStringGetCStringPtr(teamID, kCFStringEncodingUTF8));
 371         }
 372
 373         msg.send();
 374
 375         if (int64_t error = xpc_dictionary_get_int64(msg, "error")) {
 376                 MacOSError::throwMe((int)error);
 377         }
 378 }
 379
 380 } // end namespace CodeSigning
 381 } // end namespace Security