Add code to launch applications with elevated priviledges on Mac from the old updater.

src/ProcessUtils.cpp

@@ -77,6 +77,101 @@ void ProcessUtils::runElevatedLinux(const std::string& executable,
 void ProcessUtils::runElevatedMac(const std::string& executable,
 						const std::list<std::string>& args)
 {
+	OSStatus status;
+	AuthorizationRef authorizationRef;
+	
+	status = AuthorizationCreate(
+			NULL,
+			kAuthorizationEmptyEnvironment,
+			kAuthorizationFlagDefaults,
+			&authorizationRef);
+
+	AuthorizationItem right = { kAuthorizationRightExecute, 0, NULL, 0 };
+	AuthorizationRights rights = { 1, &right };
+	
+	AuthorizationFlags flags = kAuthorizationFlagDefaults |
+			kAuthorizationFlagInteractionAllowed |
+			kAuthorizationFlagPreAuthorize |
+			kAuthorizationFlagExtendRights;
+
+	if (status == errAuthorizationSuccess)
+	{
+		status = AuthorizationCopyRights(authorizationRef, &rights, NULL, 
+				flags, NULL);
+
+		if (status == errAuthorizationSuccess)
+		{
+			char** args;
+			args = (char**) malloc(sizeof(char*) * arguments.count() + 1);
+		
+			int i;
+			for (i = 0; i < arguments.size(); i++)
+			{
+				args[i] = strdup(arguments[i].c_str());
+			}
+			args[i] = NULL;
+
+			FILE* pipe = NULL;
+
+			char* tool = strdup(executable.c_str());
+			
+			status = AuthorizationExecuteWithPrivileges(authorizationRef, tool,
+					kAuthorizationFlagDefaults, args, &pipe);
+
+			if (status == errAuthorizationSuccess)
+			{
+				// AuthorizationExecuteWithPrivileges does not provide a way to get the process ID
+				// of the child process.
+				//
+				// Discussions on Apple development forums suggest two approaches for working around this,
+				//
+				// - Modify the child process to sent its process ID back to the parent via
+				//   the pipe passed to AuthorizationExecuteWithPrivileges.
+				//
+				// - Use the generic Unix wait() call.
+				//
+				// This code uses wait(), which is simpler, but suffers from the problem that wait() waits
+				// for any child process, not necessarily the specific process launched
+				// by AuthorizationExecuteWithPrivileges.
+				//
+				// Apple's documentation (see 'Authorization Services Programming Guide') suggests
+				// installing files in an installer as a legitimate use for 
+				// AuthorizationExecuteWithPrivileges but in general strongly recommends
+				// not using this call and discusses a number of other alternatives
+				// for performing privileged operations,
+				// which we could consider in future.
+
+				int childStatus;
+				pid_t childPid = wait(&childStatus);
+
+				if (childStatus != 0)
+				{
+					LOG(Error,"elevated process failed with status " + intToStr(childStatus) + " pid "
+					          + intToStr(childPid));
+				}
+				else
+				{
+					LOG(Info,"elevated process succeded with pid " + intToStr(childPid));
+				}
+			}
+			else
+			{
+				LOG(Error,"failed to launch elevated process " + intToStr(status));
+			}
+			
+			// If we want to know more information about what has happened:
+			// http://developer.apple.com/mac/library/documentation/Security/Reference/authorization_ref/Reference/reference.html#//apple_ref/doc/uid/TP30000826-CH4g-CJBEABHG
+			free(tool);
+			for (i = 0; i < arguments.count(); i++)
+			{
+				free(args[i]);
+			}
+		}
+		else
+		{
+			LOG(Error,"failed to get rights to launch elevated process. status: " + intToStr(status));
+		}
+	}
 }
 #endif