Merge branch 'dev' of http://git.int.zerotier.com/ZeroTier/ZeroTierOne into dev

2 files changed, 150 insertions, 273 deletions

diff --git a/service/SoftwareUpdater.cpp b/service/SoftwareUpdater.cpp
index 0f5b4fca..017e4f00 100644
--- a/service/SoftwareUpdater.cpp
+++ b/service/SoftwareUpdater.cpp
@@ -21,6 +21,20 @@
 #include <string.h>
 #include <stdint.h>
 
+#ifdef __WINDOWS__
+#include <WinSock2.h>
+#include <Windows.h>
+#include <ShlObj.h>
+#include <netioapi.h>
+#include <iphlpapi.h>
+#else
+#include <sys/types.h>
+#include <sys/socket.h>
+#include <sys/wait.h>
+#include <unistd.h>
+#include <ifaddrs.h>
+#endif
+
 #include "SoftwareUpdater.hpp"
 
 #include "../version.h"
@@ -42,225 +56,36 @@
 
 namespace ZeroTier {
 
-#if 0
-#ifdef ZT_AUTO_UPDATE
-#define ZT_AUTO_UPDATE_MAX_HTTP_RESPONSE_SIZE (1024 * 1024 * 64)
-#define ZT_AUTO_UPDATE_CHECK_PERIOD 21600000
-class BackgroundSoftwareUpdateChecker
-{
-public:
-	bool isValidSigningIdentity(const Identity &id)
-	{
-		return (
-			/* 0001 - 0004 : obsolete, used in old versions */
-		  /* 0005 */   (id == Identity("ba57ea350e:0:9d4be6d7f86c5660d5ee1951a3d759aa6e12a84fc0c0b74639500f1dbc1a8c566622e7d1c531967ebceb1e9d1761342f88324a8ba520c93c35f92f35080fa23f"))
-		  /* 0006 */ ||(id == Identity("5067b21b83:0:8af477730f5055c48135b84bed6720a35bca4c0e34be4060a4c636288b1ec22217eb22709d610c66ed464c643130c51411bbb0294eef12fbe8ecc1a1e2c63a7a"))
-		  /* 0007 */ ||(id == Identity("4f5e97a8f1:0:57880d056d7baeb04bbc057d6f16e6cb41388570e87f01492fce882485f65a798648595610a3ad49885604e7fb1db2dd3c2c534b75e42c3c0b110ad07b4bb138"))
-		  /* 0008 */ ||(id == Identity("580bbb8e15:0:ad5ef31155bebc6bc413991992387e083fed26d699997ef76e7c947781edd47d1997161fa56ba337b1a2b44b129fd7c7197ce5185382f06011bc88d1363b4ddd"))
-		);
-	}
-
-	void doUpdateCheck()
-	{
-		std::string url(OneService::autoUpdateUrl());
-		if ((url.length() <= 7)||(url.substr(0,7) != "http://"))
-			return;
-
-		std::string httpHost;
-		std::string httpPath;
-		{
-			std::size_t slashIdx = url.substr(7).find_first_of('/');
-			if (slashIdx == std::string::npos) {
-				httpHost = url.substr(7);
-				httpPath = "/";
-			} else {
-				httpHost = url.substr(7,slashIdx);
-				httpPath = url.substr(slashIdx + 7);
-			}
-		}
-		if (httpHost.length() == 0)
-			return;
-
-		std::vector<InetAddress> ips(OSUtils::resolve(httpHost.c_str()));
-		for(std::vector<InetAddress>::iterator ip(ips.begin());ip!=ips.end();++ip) {
-			if (!ip->port())
-				ip->setPort(80);
-			std::string nfoPath = httpPath + "LATEST.nfo";
-			std::map<std::string,std::string> requestHeaders,responseHeaders;
-			std::string body;
-			requestHeaders["Host"] = httpHost;
-			unsigned int scode = Http::GET(ZT_AUTO_UPDATE_MAX_HTTP_RESPONSE_SIZE,60000,reinterpret_cast<const struct sockaddr *>(&(*ip)),nfoPath.c_str(),requestHeaders,responseHeaders,body);
-			//fprintf(stderr,"UPDATE %s %s %u %lu\n",ip->toString().c_str(),nfoPath.c_str(),scode,body.length());
-			if ((scode == 200)&&(body.length() > 0)) {
-				/* NFO fields:
-				 *
-				 * file=<filename>
-				 * signedBy=<signing identity>
-				 * ed25519=<ed25519 ECC signature of archive in hex>
-				 * vMajor=<major version>
-				 * vMinor=<minor version>
-				 * vRevision=<revision> */
-				Dictionary<4096> nfo(body.c_str());
-				char tmp[2048];
-
-				if (nfo.get("vMajor",tmp,sizeof(tmp)) <= 0) return;
-				const unsigned int vMajor = Utils::strToUInt(tmp);
-				if (nfo.get("vMinor",tmp,sizeof(tmp)) <= 0) return;
-				const unsigned int vMinor = Utils::strToUInt(tmp);
-				if (nfo.get("vRevision",tmp,sizeof(tmp)) <= 0) return;
-				const unsigned int vRevision = Utils::strToUInt(tmp);
-				if (Utils::compareVersion(vMajor,vMinor,vRevision,ZEROTIER_ONE_VERSION_MAJOR,ZEROTIER_ONE_VERSION_MINOR,ZEROTIER_ONE_VERSION_REVISION) <= 0) {
-					//fprintf(stderr,"UPDATE %u.%u.%u is not newer than our version\n",vMajor,vMinor,vRevision);
-					return;
-				}
-
-				if (nfo.get("signedBy",tmp,sizeof(tmp)) <= 0) return;
-				Identity signedBy;
-				if ((!signedBy.fromString(tmp))||(!isValidSigningIdentity(signedBy))) {
-					//fprintf(stderr,"UPDATE invalid signedBy or not authorized signing identity.\n");
-					return;
-				}
-
-				if (nfo.get("file",tmp,sizeof(tmp)) <= 0) return;
-				std::string filePath(tmp);
-				if ((!filePath.length())||(filePath.find("..") != std::string::npos))
-					return;
-				filePath = httpPath + filePath;
-
-				std::string fileData;
-				if (Http::GET(ZT_AUTO_UPDATE_MAX_HTTP_RESPONSE_SIZE,60000,reinterpret_cast<const struct sockaddr *>(&(*ip)),filePath.c_str(),requestHeaders,responseHeaders,fileData) != 200) {
-					//fprintf(stderr,"UPDATE GET %s failed\n",filePath.c_str());
-					return;
-				}
-
-				if (nfo.get("ed25519",tmp,sizeof(tmp)) <= 0) return;
-				std::string ed25519(Utils::unhex(tmp));
-				if ((ed25519.length() == 0)||(!signedBy.verify(fileData.data(),(unsigned int)fileData.length(),ed25519.data(),(unsigned int)ed25519.length()))) {
-					//fprintf(stderr,"UPDATE %s failed signature check!\n",filePath.c_str());
-					return;
-				}
-
-				/* --------------------------------------------------------------- */
-				/* We made it! Begin OS-specific installation code. */
-
-#ifdef __APPLE__
-				/* OSX version is in the form of a MacOSX .pkg file, so we will
-				 * launch installer (normally in /usr/sbin) to install it. It will
-				 * then turn around and shut down the service, update files, and
-				 * relaunch. */
-				{
-					char bashp[128],pkgp[128];
-					Utils::snprintf(bashp,sizeof(bashp),"/tmp/ZeroTierOne-update-%u.%u.%u.sh",vMajor,vMinor,vRevision);
-					Utils::snprintf(pkgp,sizeof(pkgp),"/tmp/ZeroTierOne-update-%u.%u.%u.pkg",vMajor,vMinor,vRevision);
-					FILE *pkg = fopen(pkgp,"w");
-					if ((!pkg)||(fwrite(fileData.data(),fileData.length(),1,pkg) != 1)) {
-						fclose(pkg);
-						unlink(bashp);
-						unlink(pkgp);
-						fprintf(stderr,"UPDATE error writing %s\n",pkgp);
-						return;
-					}
-					fclose(pkg);
-					FILE *bash = fopen(bashp,"w");
-					if (!bash) {
-						fclose(pkg);
-						unlink(bashp);
-						unlink(pkgp);
-						fprintf(stderr,"UPDATE error writing %s\n",bashp);
-						return;
-					}
-					fprintf(bash,
-						"#!/bin/bash\n"
-						"export PATH=/bin:/usr/bin:/usr/sbin:/sbin:/usr/local/bin:/usr/local/sbin\n"
-						"sleep 1\n"
-						"installer -pkg \"%s\" -target /\n"
-						"sleep 1\n"
-						"rm -f \"%s\" \"%s\"\n"
-						"exit 0\n",
-						pkgp,
-						pkgp,
-						bashp);
-					fclose(bash);
-					long pid = (long)vfork();
-					if (pid == 0) {
-						setsid(); // detach from parent so that shell isn't killed when parent is killed
-						signal(SIGHUP,SIG_IGN);
-						signal(SIGTERM,SIG_IGN);
-						signal(SIGQUIT,SIG_IGN);
-						execl("/bin/bash","/bin/bash",bashp,(char *)0);
-						exit(0);
-					}
-				}
-#endif // __APPLE__
-
-#ifdef __WINDOWS__
-				/* Windows version comes in the form of .MSI package that
-				 * takes care of everything. */
-				{
-					char tempp[512],batp[512],msip[512],cmdline[512];
-					if (GetTempPathA(sizeof(tempp),tempp) <= 0)
-						return;
-					CreateDirectoryA(tempp,(LPSECURITY_ATTRIBUTES)0);
-					Utils::snprintf(batp,sizeof(batp),"%s\\ZeroTierOne-update-%u.%u.%u.bat",tempp,vMajor,vMinor,vRevision);
-					Utils::snprintf(msip,sizeof(msip),"%s\\ZeroTierOne-update-%u.%u.%u.msi",tempp,vMajor,vMinor,vRevision);
-					FILE *msi = fopen(msip,"wb");
-					if ((!msi)||(fwrite(fileData.data(),(size_t)fileData.length(),1,msi) != 1)) {
-						fclose(msi);
-						return;
-					}
-					fclose(msi);
-					FILE *bat = fopen(batp,"wb");
-					if (!bat)
-						return;
-					fprintf(bat,
-						"TIMEOUT.EXE /T 1 /NOBREAK\r\n"
-						"NET.EXE STOP \"ZeroTierOneService\"\r\n"
-						"TIMEOUT.EXE /T 1 /NOBREAK\r\n"
-						"MSIEXEC.EXE /i \"%s\" /qn\r\n"
-						"TIMEOUT.EXE /T 1 /NOBREAK\r\n"
-						"NET.EXE START \"ZeroTierOneService\"\r\n"
-						"DEL \"%s\"\r\n"
-						"DEL \"%s\"\r\n",
-						msip,
-						msip,
-						batp);
-					fclose(bat);
-					STARTUPINFOA si;
-					PROCESS_INFORMATION pi;
-					memset(&si,0,sizeof(si));
-					memset(&pi,0,sizeof(pi));
-					Utils::snprintf(cmdline,sizeof(cmdline),"CMD.EXE /c \"%s\"",batp);
-					CreateProcessA(NULL,cmdline,NULL,NULL,FALSE,CREATE_NO_WINDOW|CREATE_NEW_PROCESS_GROUP,NULL,NULL,&si,&pi);
-				}
-#endif // __WINDOWS__
-
-				/* --------------------------------------------------------------- */
-
-				return;
-			} // else try to fetch from next IP address
-		}
-	}
-
-	void threadMain()
-		throw()
-	{
-		try {
-			this->doUpdateCheck();
-		} catch ( ... ) {}
-	}
-};
-static BackgroundSoftwareUpdateChecker backgroundSoftwareUpdateChecker;
-#endif // ZT_AUTO_UPDATE
-#endif
-
 SoftwareUpdater::SoftwareUpdater(Node &node,const std::string &homePath) :
 	_node(node),
 	_lastCheckTime(0),
 	_homePath(homePath),
 	_channel(ZT_SOFTWARE_UPDATE_DEFAULT_CHANNEL),
-	_latestBinLength(0),
-	_latestBinValid(false)
+	_latestValid(false),
+	_downloadLength(0)
 {
+	// Check for a cached newer update. If there's a cached update that is not newer or looks bad, delete.
+	try {
+		std::string buf;
+		if (OSUtils::readFile((_homePath + ZT_PATH_SEPARATOR_S ZT_SOFTWARE_UPDATE_META_FILENAME).c_str(),buf)) {
+			nlohmann::json meta = OSUtils::jsonParse(buf);
+			buf = std::string();
+			const unsigned int rvMaj = (unsigned int)OSUtils::jsonInt(meta[ZT_SOFTWARE_UPDATE_JSON_VERSION_MAJOR],0);
+			const unsigned int rvMin = (unsigned int)OSUtils::jsonInt(meta[ZT_SOFTWARE_UPDATE_JSON_VERSION_MINOR],0);
+			const unsigned int rvRev = (unsigned int)OSUtils::jsonInt(meta[ZT_SOFTWARE_UPDATE_JSON_VERSION_REVISION],0);
+			if ((Utils::compareVersion(rvMaj,rvMin,rvRev,ZEROTIER_ONE_VERSION_MAJOR,ZEROTIER_ONE_VERSION_MINOR,ZEROTIER_ONE_VERSION_REVISION) > 0)&&(OSUtils::readFile((_homePath + ZT_PATH_SEPARATOR_S ZT_SOFTWARE_UPDATE_BIN_FILENAME).c_str(),buf))) {
+				if ((uint64_t)buf.length() == OSUtils::jsonInt(meta[ZT_SOFTWARE_UPDATE_JSON_UPDATE_SIZE],0)) {
+					_latestMeta = meta;
+					_latestValid = true;
+					//printf("CACHED UPDATE IS NEWER AND LOOKS GOOD\n");
+				}
+			}
+		}
+	} catch ( ... ) {} // exceptions indicate invalid cached update
+	if (!_latestValid) {
+		OSUtils::rm((_homePath + ZT_PATH_SEPARATOR_S ZT_SOFTWARE_UPDATE_META_FILENAME).c_str());
+		OSUtils::rm((_homePath + ZT_PATH_SEPARATOR_S ZT_SOFTWARE_UPDATE_BIN_FILENAME).c_str());
+	}
 }
 
 SoftwareUpdater::~SoftwareUpdater()
@@ -286,8 +111,9 @@ void SoftwareUpdater::setUpdateDistribution(bool distribute)
 							uint8_t sha512[ZT_SHA512_DIGEST_LEN];
 							SHA512::hash(sha512,d.bin.data(),(unsigned int)d.bin.length());
 							if (!memcmp(sha512,metaHash.data(),ZT_SHA512_DIGEST_LEN)) { // double check that hash in JSON is correct
+								d.meta[ZT_SOFTWARE_UPDATE_JSON_UPDATE_SIZE] = d.bin.length(); // override with correct value -- setting this in meta json is optional
 								_dist[Array<uint8_t,16>(sha512)] = d;
-								printf("update-dist.d: %s\n",u->c_str());
+								//printf("update-dist.d: %s\n",u->c_str());
 							}
 						}
 					} catch ( ... ) {} // ignore bad meta JSON, etc.
@@ -351,19 +177,24 @@ void SoftwareUpdater::handleSoftwareUpdateUserMessage(uint64_t origin,const void
 							if ((len <= ZT_SOFTWARE_UPDATE_MAX_SIZE)&&(hash.length() >= 16)) {
 								if (_latestMeta != req) {
 									_latestMeta = req;
-									_latestBin = "";
-									memcpy(_latestBinHashPrefix.data,hash.data(),16);
-									_latestBinLength = len;
-									_latestBinValid = false;
-									printf("<< LATEST\n%s\n",OSUtils::jsonDump(req).c_str());
+									_latestValid = false;
+
+									OSUtils::rm((_homePath + ZT_PATH_SEPARATOR_S ZT_SOFTWARE_UPDATE_META_FILENAME).c_str());
+									OSUtils::rm((_homePath + ZT_PATH_SEPARATOR_S ZT_SOFTWARE_UPDATE_BIN_FILENAME).c_str());
+
+									_download = std::string();
+									memcpy(_downloadHashPrefix.data,hash.data(),16);
+									_downloadLength = len;
 								}
 
-								Buffer<128> gd;
-								gd.append((uint8_t)VERB_GET_DATA);
-								gd.append(_latestBinHashPrefix.data,16);
-								gd.append((uint32_t)_latestBin.length());
-								_node.sendUserMessage(ZT_SOFTWARE_UPDATE_SERVICE,ZT_SOFTWARE_UPDATE_USER_MESSAGE_TYPE,gd.data(),gd.size());
-								printf(">> GET_DATA @%u\n",(unsigned int)_latestBin.length());
+								if ((_downloadLength > 0)&&(_download.length() < _downloadLength)) {
+									Buffer<128> gd;
+									gd.append((uint8_t)VERB_GET_DATA);
+									gd.append(_downloadHashPrefix.data,16);
+									gd.append((uint32_t)_download.length());
+									_node.sendUserMessage(ZT_SOFTWARE_UPDATE_SERVICE,ZT_SOFTWARE_UPDATE_USER_MESSAGE_TYPE,gd.data(),gd.size());
+									//printf(">> GET_DATA @%u\n",(unsigned int)_download.length());
+								}
 							}
 						}
 
@@ -377,36 +208,36 @@ void SoftwareUpdater::handleSoftwareUpdateUserMessage(uint64_t origin,const void
 					idx |= (unsigned long)*(reinterpret_cast<const uint8_t *>(data) + 18) << 16;
 					idx |= (unsigned long)*(reinterpret_cast<const uint8_t *>(data) + 19) << 8;
 					idx |= (unsigned long)*(reinterpret_cast<const uint8_t *>(data) + 20);
-					printf("<< GET_DATA @%u from %.10llx for %s\n",(unsigned int)idx,origin,Utils::hex(reinterpret_cast<const uint8_t *>(data) + 1,16).c_str());
+					//printf("<< GET_DATA @%u from %.10llx for %s\n",(unsigned int)idx,origin,Utils::hex(reinterpret_cast<const uint8_t *>(data) + 1,16).c_str());
 					std::map< Array<uint8_t,16>,_D >::iterator d(_dist.find(Array<uint8_t,16>(reinterpret_cast<const uint8_t *>(data) + 1)));
-					if ((d != _dist.end())&&(idx < d->second.bin.length())) {
+					if ((d != _dist.end())&&(idx < (unsigned long)d->second.bin.length())) {
 						Buffer<ZT_SOFTWARE_UPDATE_CHUNK_SIZE + 128> buf;
 						buf.append((uint8_t)VERB_DATA);
 						buf.append(reinterpret_cast<const uint8_t *>(data) + 1,16);
 						buf.append((uint32_t)idx);
 						buf.append(d->second.bin.data() + idx,std::min((unsigned long)ZT_SOFTWARE_UPDATE_CHUNK_SIZE,(unsigned long)(d->second.bin.length() - idx)));
 						_node.sendUserMessage(origin,ZT_SOFTWARE_UPDATE_USER_MESSAGE_TYPE,buf.data(),buf.size());
-						printf(">> DATA @%u\n",(unsigned int)idx);
+						//printf(">> DATA @%u\n",(unsigned int)idx);
 					}
 				}
 				break;
 
 			case VERB_DATA:
-				if ((len >= 21)&&(!memcmp(_latestBinHashPrefix.data,reinterpret_cast<const uint8_t *>(data) + 1,16))) {
+				if ((len >= 21)&&(_downloadLength > 0)&&(!memcmp(_downloadHashPrefix.data,reinterpret_cast<const uint8_t *>(data) + 1,16))) {
 					unsigned long idx = (unsigned long)*(reinterpret_cast<const uint8_t *>(data) + 17) << 24;
 					idx |= (unsigned long)*(reinterpret_cast<const uint8_t *>(data) + 18) << 16;
 					idx |= (unsigned long)*(reinterpret_cast<const uint8_t *>(data) + 19) << 8;
 					idx |= (unsigned long)*(reinterpret_cast<const uint8_t *>(data) + 20);
-					printf("<< DATA @%u / %u bytes (we now have %u bytes)\n",(unsigned int)idx,(unsigned int)(len - 21),(unsigned int)_latestBin.length());
-					if (idx == _latestBin.length()) {
-						_latestBin.append(reinterpret_cast<const char *>(data) + 21,len - 21);
-						if (_latestBin.length() < _latestBinLength) {
+					//printf("<< DATA @%u / %u bytes (we now have %u bytes)\n",(unsigned int)idx,(unsigned int)(len - 21),(unsigned int)_download.length());
+					if (idx == (unsigned long)_download.length()) {
+						_download.append(reinterpret_cast<const char *>(data) + 21,len - 21);
+						if (_download.length() < _downloadLength) {
 							Buffer<128> gd;
 							gd.append((uint8_t)VERB_GET_DATA);
-							gd.append(_latestBinHashPrefix.data,16);
-							gd.append((uint32_t)_latestBin.length());
+							gd.append(_downloadHashPrefix.data,16);
+							gd.append((uint32_t)_download.length());
 							_node.sendUserMessage(ZT_SOFTWARE_UPDATE_SERVICE,ZT_SOFTWARE_UPDATE_USER_MESSAGE_TYPE,gd.data(),gd.size());
-							printf(">> GET_DATA @%u\n",(unsigned int)_latestBin.length());
+							//printf(">> GET_DATA @%u\n",(unsigned int)_download.length());
 						}
 					}
 				}
@@ -444,47 +275,57 @@ bool SoftwareUpdater::check(const uint64_t now)
 			(int)ZT_VENDOR_ZEROTIER,
 			_channel.c_str());
 		_node.sendUserMessage(ZT_SOFTWARE_UPDATE_SERVICE,ZT_SOFTWARE_UPDATE_USER_MESSAGE_TYPE,tmp,len);
-		printf(">> GET_LATEST\n");
+		//printf(">> GET_LATEST\n");
 	}
 
-	if (_latestBinLength > 0) {
-		if (_latestBin.length() >= _latestBinLength) {
-			if (_latestBinValid) {
-				return true;
-			} else {
-				// This is the very important security validation part that makes sure
-				// this software update doesn't have cooties.
-
-				try {
-					// (1) Check the hash itself to make sure the image is basically okay
-					uint8_t sha512[ZT_SHA512_DIGEST_LEN];
-					SHA512::hash(sha512,_latestBin.data(),(unsigned int)_latestBin.length());
-					if (Utils::hex(sha512,ZT_SHA512_DIGEST_LEN) == OSUtils::jsonString(_latestMeta[ZT_SOFTWARE_UPDATE_JSON_UPDATE_HASH],"~")) {
-						// (2) Check signature by signing authority
-						std::string sig(OSUtils::jsonBinFromHex(_latestMeta[ZT_SOFTWARE_UPDATE_JSON_UPDATE_SIGNATURE]));
-						if (Identity(ZT_SOFTWARE_UPDATE_SIGNING_AUTHORITY).verify(_latestBin.data(),(unsigned int)_latestBin.length(),sig.data(),(unsigned int)sig.length())) {
-							// If we passed both of these, the update is good!
-							_latestBinValid = true;
-							printf("VALID UPDATE\n%s\n",OSUtils::jsonDump(_latestMeta).c_str());
+	if (_latestValid)
+		return true;
+
+	if (_downloadLength > 0) {
+		if (_download.length() >= _downloadLength) {
+			// This is the very important security validation part that makes sure
+			// this software update doesn't have cooties.
+
+			const std::string metaPath(_homePath + ZT_PATH_SEPARATOR_S ZT_SOFTWARE_UPDATE_META_FILENAME);
+			const std::string binPath(_homePath + ZT_PATH_SEPARATOR_S ZT_SOFTWARE_UPDATE_BIN_FILENAME);
+
+			try {
+				// (1) Check the hash itself to make sure the image is basically okay
+				uint8_t sha512[ZT_SHA512_DIGEST_LEN];
+				SHA512::hash(sha512,_download.data(),(unsigned int)_download.length());
+				if (Utils::hex(sha512,ZT_SHA512_DIGEST_LEN) == OSUtils::jsonString(_latestMeta[ZT_SOFTWARE_UPDATE_JSON_UPDATE_HASH],"~")) {
+					// (2) Check signature by signing authority
+					std::string sig(OSUtils::jsonBinFromHex(_latestMeta[ZT_SOFTWARE_UPDATE_JSON_UPDATE_SIGNATURE]));
+					if (Identity(ZT_SOFTWARE_UPDATE_SIGNING_AUTHORITY).verify(_download.data(),(unsigned int)_download.length(),sig.data(),(unsigned int)sig.length())) {
+						// (3) Try to save file, and if so we are good.
+						if (OSUtils::writeFile(metaPath.c_str(),OSUtils::jsonDump(_latestMeta)) && OSUtils::writeFile(binPath.c_str(),_download)) {
+							OSUtils::lockDownFile(metaPath.c_str(),false);
+							OSUtils::lockDownFile(binPath.c_str(),false);
+							_latestValid = true;
+							//printf("VALID UPDATE\n%s\n",OSUtils::jsonDump(_latestMeta).c_str());
+							_download = std::string();
+							_downloadLength = 0;
 							return true;
 						}
 					}
-				} catch ( ... ) {} // any exception equals verification failure
-				printf("INVALID UPDATE (!!!)\n%s\n",OSUtils::jsonDump(_latestMeta).c_str());
-
-				// If we get here, checks failed.
-				_latestMeta = nlohmann::json();
-				_latestBin = "";
-				_latestBinLength = 0;
-				_latestBinValid = false;
-			}
+				}
+			} catch ( ... ) {} // any exception equals verification failure
+
+			// If we get here, checks failed.
+			//printf("INVALID UPDATE (!!!)\n%s\n",OSUtils::jsonDump(_latestMeta).c_str());
+			OSUtils::rm(metaPath.c_str());
+			OSUtils::rm(binPath.c_str());
+			_latestMeta = nlohmann::json();
+			_latestValid = false;
+			_download = std::string();
+			_downloadLength = 0;
 		} else {
 			Buffer<128> gd;
 			gd.append((uint8_t)VERB_GET_DATA);
-			gd.append(_latestBinHashPrefix.data,16);
-			gd.append((uint32_t)_latestBin.length());
+			gd.append(_downloadHashPrefix.data,16);
+			gd.append((uint32_t)_download.length());
 			_node.sendUserMessage(ZT_SOFTWARE_UPDATE_SERVICE,ZT_SOFTWARE_UPDATE_USER_MESSAGE_TYPE,gd.data(),gd.size());
-			printf(">> GET_DATA @%u\n",(unsigned int)_latestBin.length());
+			//printf(">> GET_DATA @%u\n",(unsigned int)_download.length());
 		}
 	}
 
@@ -493,7 +334,32 @@ bool SoftwareUpdater::check(const uint64_t now)
 
 void SoftwareUpdater::apply()
 {
-	if ((_latestBin.length() > 0)&&(_latestBinValid)) {
+	std::string updatePath(_homePath + ZT_PATH_SEPARATOR_S ZT_SOFTWARE_UPDATE_BIN_FILENAME);
+	if ((_latestMeta.is_object())&&(_latestValid)&&(OSUtils::fileExists(updatePath.c_str(),false))) {
+#ifdef __WINDOWS__
+		std::string cmdArgs(OSUtils::jsonString(_latestMeta[ZT_SOFTWARE_UPDATE_JSON_UPDATE_EXEC_ARGS],""));
+		if (cmdArgs.length() > 0) {
+			updatePath.push_back(' ');
+			updatePath.append(cmdArgs);
+		}
+		STARTUPINFOA si;
+		PROCESS_INFORMATION pi;
+		memset(&si,0,sizeof(si));
+		memset(&pi,0,sizeof(pi));
+		CreateProcessA(NULL,updatePath.c_str(),NULL,NULL,FALSE,CREATE_NO_WINDOW|CREATE_NEW_PROCESS_GROUP,NULL,NULL,&si,&pi);
+#else
+		char *argv[256];
+		unsigned long ac = 0;
+		argv[ac++] = const_cast<char *>(updatePath.c_str());
+		std::vector<std::string> argsSplit(OSUtils::split(OSUtils::jsonString(_latestMeta[ZT_SOFTWARE_UPDATE_JSON_UPDATE_EXEC_ARGS],"").c_str()," ","\\","\""));
+		for(std::vector<std::string>::iterator a(argsSplit.begin());a!=argsSplit.end();++a) {
+			argv[ac] = const_cast<char *>(a->c_str());
+			if (++ac == 255) break;
+		}
+		argv[ac] = (char *)0;
+		chmod(updatePath.c_str(),0700);
+		execv(updatePath.c_str(),argv);
+#endif
 	}
 }
 
diff --git a/service/SoftwareUpdater.hpp b/service/SoftwareUpdater.hpp
index b9cabf23..26e44f86 100644
--- a/service/SoftwareUpdater.hpp
+++ b/service/SoftwareUpdater.hpp
@@ -69,6 +69,16 @@
  */
 #define ZT_SOFTWARE_UPDATE_DEFAULT_CHANNEL "release"
 
+/**
+ * Filename for latest update's meta JSON
+ */
+#define ZT_SOFTWARE_UPDATE_META_FILENAME "latest-update.json"
+
+/**
+ * Filename for latest update's binary image
+ */
+#define ZT_SOFTWARE_UPDATE_BIN_FILENAME "latest-update.exe"
+
 #define ZT_SOFTWARE_UPDATE_JSON_VERSION_MAJOR "versionMajor"
 #define ZT_SOFTWARE_UPDATE_JSON_VERSION_MINOR "versionMinor"
 #define ZT_SOFTWARE_UPDATE_JSON_VERSION_REVISION "versionRev"
@@ -188,10 +198,11 @@ private:
 	std::map< Array<uint8_t,16>,_D > _dist; // key is first 16 bytes of hash
 
 	nlohmann::json _latestMeta;
-	std::string _latestBin;
-	Array<uint8_t,16> _latestBinHashPrefix;
-	unsigned long _latestBinLength;
-	bool _latestBinValid;
+	bool _latestValid;
+
+	std::string _download;
+	Array<uint8_t,16> _downloadHashPrefix;
+	unsigned long _downloadLength;
 };
 
 } // namespace ZeroTier