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
  32 namespace Security {
  33 namespace CodeSigning {
  34
  35
  36 static void doProgress(xpc_object_t msg);
  37
  38
  39 static const char serviceName[] = "com.apple.security.syspolicy";
  40
  41
  42 static dispatch_once_t dispatchInit;            // one-time init marker
  43 static xpc_connection_t service;                        // connection to spd
  44 static dispatch_queue_t queue;                          // dispatch queue for service
  45
  46 static void init()
  47 {
  48         dispatch_once(&dispatchInit, ^void(void) {
  49                 const char *name = serviceName;
  50                 if (const char *env = getenv("SYSPOLICYNAME"))
  51                         name = env;
  52                 queue = dispatch_queue_create("spd-client", 0);
  53                 service = xpc_connection_create_mach_service(name, queue, XPC_CONNECTION_MACH_SERVICE_PRIVILEGED);
  54                 xpc_connection_set_event_handler(service, ^(xpc_object_t msg) {
  55                         if (xpc_get_type(msg) == XPC_TYPE_DICTIONARY) {
  56                                 const char *function = xpc_dictionary_get_string(msg, "function");
  57                                 if (!strcmp(function, "progress")) {
  58                                         doProgress(msg);
  59                                 }
  60                         }
  61                 });
  62                 xpc_connection_resume(service);
  63         });
  64 }
  65
  66
  67 //
  68 // Your standard XPC client-side machinery
  69 //
  70 class Message {
  71 public:
  72         xpc_object_t obj;
  73
  74         Message(const char *function)
  75         {
  76                 init();
  77                 obj = xpc_dictionary_create(NULL, NULL, 0);
  78                 xpc_dictionary_set_string(obj, "function", function);
  79         }
  80         ~Message()
  81         {
  82                 if (obj)
  83                         xpc_release(obj);
  84         }
  85         operator xpc_object_t () { return obj; }
  86
  87         void send()
  88         {
  89                 xpc_object_t reply = xpc_connection_send_message_with_reply_sync(service, obj);
  90                 xpc_release(obj);
  91                 obj = NULL;
  92                 xpc_type_t type = xpc_get_type(reply);
  93                 if (type == XPC_TYPE_DICTIONARY) {
  94                         obj = reply;
  95                         if (int64_t error = xpc_dictionary_get_int64(obj, "error"))
  96                                 MacOSError::throwMe((int)error);
  97                 } else if (type == XPC_TYPE_ERROR) {
  98                         const char *s = xpc_copy_description(reply);
  99                         printf("Error returned: %s\n", s);
 100             Syslog::notice("code signing internal problem: unexpected error from xpc: %s", s);
 101                         free((char*)s);
 102             MacOSError::throwMe(errSecCSInternalError);
 103                 } else {
 104                         const char *s = xpc_copy_description(reply);
 105                         printf("Unexpected type of return object: %s\n", s);
 106                         free((char*)s);
 107                 }
 108         }
 109 };
 110
 111
 112
 113 static void copyCFDictionary(const void *key, const void *value, void *ctx)
 114 {
 115         CFMutableDictionaryRef target = CFMutableDictionaryRef(ctx);
 116         if (CFGetTypeID(value) == CFURLGetTypeID()) {
 117                 CFRef<CFStringRef> path = CFURLCopyFileSystemPath(CFURLRef(value), kCFURLPOSIXPathStyle);
 118                 CFDictionaryAddValue(target, key, path);
 119         } else if (CFEqual(key, kSecAssessmentContextKeyFeedback)) {
 120                 CFDictionaryAddValue(target, key, CFTempNumber(uint64_t(value)));
 121         } else {
 122                 CFDictionaryAddValue(target, key, value);
 123         }
 124 }
 125
 126
 127 static bool precheckAccess(CFURLRef path, CFDictionaryRef context)
 128 {
 129         CFTypeRef type = CFDictionaryGetValue(context, kSecAssessmentContextKeyOperation);
 130         if (type == NULL || CFEqual(type, kSecAssessmentOperationTypeExecute)) {
 131                 CFRef<SecStaticCodeRef> code;
 132                 OSStatus rc = SecStaticCodeCreateWithPath(path, kSecCSDefaultFlags, &code.aref());
 133         if (rc == errSecCSBadBundleFormat)  // work around <rdar://problem/26075034>
 134             return false;
 135                 CFRef<CFURLRef> exec;
 136                 MacOSError::check(SecCodeCopyPath(code, kSecCSDefaultFlags, &exec.aref()));
 137                 UnixError::check(::access(cfString(exec).c_str(), R_OK));
 138         } else {
 139                 UnixError::check(access(cfString(path).c_str(), R_OK));
 140         }
 141     return true;
 142 }
 143
 144
 145 void xpcEngineAssess(CFURLRef path, SecAssessmentFlags flags, CFDictionaryRef context, CFMutableDictionaryRef result)
 146 {
 147         precheckAccess(path, context);
 148         Message msg("assess");
 149         xpc_dictionary_set_string(msg, "path", cfString(path).c_str());
 150         xpc_dictionary_set_int64(msg, "flags", flags);
 151         CFRef<CFMutableDictionaryRef> ctx = makeCFMutableDictionary();
 152         if (context)
 153                 CFDictionaryApplyFunction(context, copyCFDictionary, ctx);
 154         CFRef<CFDataRef> contextData = makeCFData(CFDictionaryRef(ctx));
 155         xpc_dictionary_set_data(msg, "context", CFDataGetBytePtr(contextData), CFDataGetLength(contextData));
 156
 157         msg.send();
 158
 159         if (int64_t error = xpc_dictionary_get_int64(msg, "error"))
 160                 MacOSError::throwMe((int)error);
 161
 162         size_t resultLength;
 163         const void *resultData = xpc_dictionary_get_data(msg, "result", &resultLength);
 164         CFRef<CFDictionaryRef> resultDict = makeCFDictionaryFrom(resultData, resultLength);
 165         CFDictionaryApplyFunction(resultDict, copyCFDictionary, result);
 166         CFDictionaryAddValue(result, CFSTR("assessment:remote"), kCFBooleanTrue);
 167 }
 168
 169 static void doProgress(xpc_object_t msg)
 170 {
 171         uint64_t current = xpc_dictionary_get_uint64(msg, "current");
 172         uint64_t total = xpc_dictionary_get_uint64(msg, "total");
 173         uint64_t ref = xpc_dictionary_get_uint64(msg, "ref");
 174         const char *token = xpc_dictionary_get_string(msg, "token");
 175         SecAssessmentFeedback feedback = SecAssessmentFeedback(ref);
 176         CFTemp<CFDictionaryRef> info("{current=%d,total=%d}", current, total);
 177         Boolean proceed = feedback(kSecAssessmentFeedbackProgress, info);
 178         if (!proceed) {
 179                 xpc_connection_t connection = xpc_dictionary_get_remote_connection(msg);
 180                 xpc_object_t cancelRequest = xpc_dictionary_create(NULL, NULL, 0);
 181                 xpc_dictionary_set_string(cancelRequest, "function", "cancel");
 182                 xpc_dictionary_set_string(cancelRequest, "token", token);
 183                 xpc_connection_send_message(connection, cancelRequest);
 184                 xpc_release(cancelRequest);
 185         }
 186 }
 187
 188
 189 CFDictionaryRef xpcEngineUpdate(CFTypeRef target, SecAssessmentFlags flags, CFDictionaryRef context)
 190 {
 191         Message msg("update");
 192         // target can be NULL, a CFURLRef, a SecRequirementRef, or a CFNumberRef
 193         if (target) {
 194                 if (CFGetTypeID(target) == CFNumberGetTypeID())
 195                         xpc_dictionary_set_uint64(msg, "rule", cfNumber<int64_t>(CFNumberRef(target)));
 196                 else if (CFGetTypeID(target) == CFURLGetTypeID()) {
 197                         bool good = precheckAccess(CFURLRef(target), context);
 198             if (!good)      // work around <rdar://problem/26075034>
 199                 return makeCFDictionary(0); // pretend this worked
 200                         xpc_dictionary_set_string(msg, "url", cfString(CFURLRef(target)).c_str());
 201                 } else if (CFGetTypeID(target) == SecRequirementGetTypeID()) {
 202                         CFRef<CFDataRef> data;
 203                         MacOSError::check(SecRequirementCopyData(SecRequirementRef(target), kSecCSDefaultFlags, &data.aref()));
 204                         xpc_dictionary_set_data(msg, "requirement", CFDataGetBytePtr(data), CFDataGetLength(data));
 205                 } else
 206                         MacOSError::throwMe(errSecCSInvalidObjectRef);
 207         }
 208         xpc_dictionary_set_int64(msg, "flags", flags);
 209         CFRef<CFMutableDictionaryRef> ctx = makeCFMutableDictionary();
 210         if (context)
 211                 CFDictionaryApplyFunction(context, copyCFDictionary, ctx);
 212         AuthorizationRef localAuthorization = NULL;
 213         if (CFDictionaryGetValue(ctx, kSecAssessmentUpdateKeyAuthorization) == NULL) {  // no caller-provided authorization
 214                 MacOSError::check(AuthorizationCreate(NULL, NULL, kAuthorizationFlagDefaults, &localAuthorization));
 215                 AuthorizationExternalForm extForm;
 216                 MacOSError::check(AuthorizationMakeExternalForm(localAuthorization, &extForm));
 217                 CFDictionaryAddValue(ctx, kSecAssessmentUpdateKeyAuthorization, CFTempData(&extForm, sizeof(extForm)));
 218         }
 219         CFRef<CFDataRef> contextData = makeCFData(CFDictionaryRef(ctx));
 220         xpc_dictionary_set_data(msg, "context", CFDataGetBytePtr(contextData), CFDataGetLength(contextData));
 221
 222         msg.send();
 223
 224         if (localAuthorization)
 225                 AuthorizationFree(localAuthorization, kAuthorizationFlagDefaults);
 226
 227     if (int64_t error = xpc_dictionary_get_int64(msg, "error"))
 228         MacOSError::throwMe((int)error);
 229
 230         size_t resultLength;
 231         const void *resultData = xpc_dictionary_get_data(msg, "result", &resultLength);
 232         return makeCFDictionaryFrom(resultData, resultLength);
 233 }
 234
 235
 236 bool xpcEngineControl(const char *control)
 237 {
 238         Message msg("control");
 239         xpc_dictionary_set_string(msg, "control", control);
 240         msg.send();
 241         return true;
 242 }
 243
 244
 245 void xpcEngineRecord(CFDictionaryRef info)
 246 {
 247         Message msg("record");
 248         CFRef<CFDataRef> infoData = makeCFData(CFDictionaryRef(info));
 249         xpc_dictionary_set_data(msg, "info", CFDataGetBytePtr(infoData), CFDataGetLength(infoData));
 250
 251         msg.send();
 252 }
 253
 254 void xpcEngineCheckDevID(CFBooleanRef* result)
 255 {
 256     Message msg("check-dev-id");
 257
 258     msg.send();
 259
 260     if (int64_t error = xpc_dictionary_get_int64(msg, "error")) {
 261         MacOSError::throwMe((int)error);
 262     }
 263
 264     *result = xpc_dictionary_get_bool(msg,"result") ? kCFBooleanTrue : kCFBooleanFalse;
 265 }
 266
 267
 268 } // end namespace CodeSigning
 269 } // end namespace Security