Updater: Better flow for performing updates; added MD5 validation.

include/updater.h

@@ -1,8 +1,10 @@
 #pragma once
 
+#include "http_client_wrapper.h"
+
 class Updater {
 public:
-	static void run();
-	static bool do_update(int cmd, String url);
-	static void update_spiffs();
+	static void run(uint16_t spiffs_version = 0);
+	static bool do_update(int cmd, String url, String expected_md5);
+	static bool read_line(String* dst, HTTPClientWrapper* http, String expected_key);
 };

src/main.cpp

@@ -136,9 +136,7 @@ void setup() {
 	}
 	
 	#ifdef OTA_UPDATE_URL
-	if (spiffs_version < OTA_VERSION) {
-		Updater::run();
-	}
+	Updater::run(spiffs_version);
 	#endif
 
     INFO("Initialization completed.\n");

src/updater.cpp

@@ -4,7 +4,8 @@
 #include "updater.h"
 #include "http_client_wrapper.h"
 
-void Updater::run() {
+void Updater::run(uint16_t spiffs_version) {
+	bool update_image = true;
 	DEBUG("Updater is running...\n");
 	HTTPClientWrapper* http = new HTTPClientWrapper();
 	DEBUG("Requesting update info...\n");
@@ -13,47 +14,74 @@ void Updater::run() {
 		ERROR("Updater failed requesting %s.\n", OTA_UPDATE_URL);
 		return;
 	}
-	String line = http->readUntil("\n");
-	if (!line.startsWith("VERSION=")) {
-		ERROR("Expected first line to be VERSION.\n");
+
+	String line_str = "";
+	if (!read_line(&line_str, http, "VERSION")) {
 		return;
 	}
-	uint16_t version = line.substring(8).toInt();
+	uint16_t version = line_str.toInt();
 	if (version==0) {
 		ERROR("Could not parse version number.\n");
 		return;
 	}
 	DEBUG("Found version %d. My version is %d.\n", version, OTA_VERSION);
 	if (version <= OTA_VERSION) {
+		if (spiffs_version>0 && spiffs_version < version) {
+			update_image = false;
+			DEBUG("SPIFFS needs an update. Continuing.\n");
+		} else {
+			return;
+		}
+	}
+	
+	String image_path = "";
+	if (!read_line(&image_path, http, "IMAGE_PATH")) {
 		return;
 	}
-	line = http->readUntil("\n");
-	if (!line.startsWith("IMAGE_PATH=")) {
-		ERROR("Expected second line to be IMAGE_PATH.\n");
+	
+	String image_md5 = "";
+	if (!read_line(&image_md5, http, "IMAGE_MD5")) {
 		return;
 	}
-	String image_path = line.substring(11);
-	image_path.trim();
-	line = http->readUntil("\n");
-	if (!line.startsWith("SPIFFS_PATH=")) {
-		ERROR("Expected third line to be SPIFFS_PATH.\n");
+
+	String spiffs_path = "";
+	if (!read_line(&spiffs_path, http, "SPIFFS_PATH")) {
+		return;
+	}
+	
+	String spiffs_md5 = "";
+	if (!read_line(&spiffs_md5, http, "SPIFFS_MD5")) {
 		return;
 	}
-	String spiffs_path = line.substring(12);
-	spiffs_path.trim();
 	
 	http->close();
 	delete http;
 	
-	result = do_update(U_FLASH, image_path);
+	result = true;
+	if (update_image) {
+		result = do_update(U_FLASH, image_path, image_md5);
+	}
 	if (result) {
-		do_update(U_SPIFFS, spiffs_path);
+		do_update(U_SPIFFS, spiffs_path, spiffs_md5);
 	}
 	DEBUG("Done. Rebooting...\n");
 	ESP.restart();
 }
 
-bool Updater::do_update(int command, String url) {
+bool Updater::read_line(String* dst, HTTPClientWrapper* http, String expected_key) {
+	expected_key += "=";
+	String line = http->readUntil("\n");
+	if (!line.startsWith(expected_key)) {
+		ERROR("Expected line start with '%s', but it started with '%s'.\n", expected_key.c_str(), line.c_str());
+		return false;
+	}
+	line = line.substring(expected_key.length());
+	line.trim();
+	dst->concat(line);
+	return true;
+}
+
+bool Updater::do_update(int command, String url, String expected_md5) {
 	HTTPClientWrapper* http = new HTTPClientWrapper();
 	bool result = http->get(url);
 	if (!result) {
@@ -66,10 +94,11 @@ bool Updater::do_update(int command, String url) {
 		ERROR("Update could not be started.\n");
 		return false;
 	}
+	Update.setMD5(expected_md5.c_str());
 	uint8_t buf[512];
 	uint16_t len;
 	while((len = http->read(buf, 512))) {
-		Update.write(buf, 512);
+		Update.write(buf, len);
 	}
 	
 	http->close();
@@ -77,51 +106,9 @@ bool Updater::do_update(int command, String url) {
 	
 	result = Update.end();
 	if (!result) {
-		ERROR("Writing the update failed somewhere. Aborted.\n");
+		const char* error = Update.errorString();
+		ERROR("Writing the update failed. The error was: %s\n", error);
 		return false;
 	}
 	return true;
 }
-
-void Updater::update_spiffs() {
-	HTTPClientWrapper* http = new HTTPClientWrapper();
-	DEBUG("Requesting update info...\n");
-	bool result = http->get(OTA_UPDATE_URL);
-	if (!result) {
-		ERROR("Updater failed requesting %s.\n", OTA_UPDATE_URL);
-		return;
-	}
-	String line = http->readUntil("\n");
-	if (!line.startsWith("VERSION=")) {
-		ERROR("Expected first line to be VERSION.\n");
-		return;
-	}
-	uint16_t version = line.substring(8).toInt();
-	if (version==0) {
-		ERROR("Could not parse version number.\n");
-		return;
-	} else if (version > OTA_VERSION) {
-		DEBUG("Found newer version %d. My version is %d. Starting full update!\n", version, OTA_VERSION);
-		run();
-	} else {
-		DEBUG("Loading SPIFFS image.\n");
-		line = http->readUntil("\n");
-		if (!line.startsWith("IMAGE_PATH=")) {
-			ERROR("Expected second line to be IMAGE_PATH.\n");
-			return;
-		}
-		line = http->readUntil("\n");
-		if (!line.startsWith("SPIFFS_PATH=")) {
-			ERROR("Expected third line to be SPIFFS_PATH.\n");
-			return;
-		}
-		String spiffs_path = line.substring(12);
-		spiffs_path.trim();
-		do_update(U_SPIFFS, spiffs_path);
-		DEBUG("Done. Rebooting...\n");
-		delay(500);
-		ESP.restart();
-	}
-	http->close();
-	delete http;
-}

update.manifest

@@ -1,3 +1,5 @@
 VERSION=1
 IMAGE_PATH=https://files.schle.nz/esmp3/firmware.bin
+IMAGE_MD5=ead8d94ae8a3c9f46e7ee65e2270fd69
 SPIFFS_PATH=https://files.schle.nz/esmp3/spiffs.bin
+SPIFFS_MD5=9f3902e3312863da8326e7fbe9485c9e