├── .github └── workflows │ ├── build.yml │ └── greetings.yml ├── .gitignore ├── DebugMacros.h ├── Extra ├── Contributors.txt ├── Test-REST-API-calendar.jpg ├── chart.jpg ├── output.jpg ├── redirection.png ├── redirection.svg └── spreadsheet.jpg ├── GoogleDocs.ino ├── GoogleScript.gs ├── HTTPSRedirect.cpp ├── HTTPSRedirect.h ├── HTTPSRedirect.ino ├── LICENSE ├── README.md ├── config.cpp ├── keywords.txt ├── library.json └── library.properties /.github/workflows/build.yml: -------------------------------------------------------------------------------- 1 | # Ref: https://github.com/arduino/arduino-cli-example/blob/master/.github/workflows/test.yaml 2 | 3 | name: build 4 | 5 | # Controls when the workflow will run 6 | on: 7 | # Triggers the workflow on push or pull request events but only for the main branch 8 | push: 9 | branches: [ main ] 10 | pull_request: 11 | branches: [ main ] 12 | 13 | # Allows you to run this workflow manually from the Actions tab 14 | workflow_dispatch: 15 | 16 | # A workflow run is made up of one or more jobs that can run sequentially or in parallel 17 | jobs: 18 | 19 | # This workflow contains a single job called "build" 20 | build: 21 | # Here we tell GitHub that the jobs must be determined 22 | # dynamically depending on a matrix configuration. 23 | strategy: 24 | matrix: 25 | # The matrix will produce one job for each configuration 26 | # parameter of type `arduino-platform`, in this case a 27 | # total of 2. 28 | arduino-platform: ["esp8266:esp8266"] 29 | # This is usually optional but we need to statically define the 30 | # FQBN of the boards we want to test for each platform. In the 31 | # future the CLI might automatically detect and download the core 32 | # needed to compile against a certain FQBN, at that point the 33 | # following `include` section will be useless. 34 | include: 35 | #- arduino-platform: "arduino:avr" 36 | # fqbn: "arduino:avr:unowifi" 37 | - arduino-platform: "esp8266:esp8266" 38 | fqbn: "esp8266:esp8266:generic:xtal=160,baud=57600" 39 | 40 | 41 | # The type of runner that the job will run on 42 | runs-on: windows-latest 43 | 44 | # Environment variables 45 | env: 46 | ARDUINO_BOARD_MANAGER_ADDITIONAL_URLS: https://arduino.esp8266.com/stable/package_esp8266com_index.json 47 | 48 | # Steps represent a sequence of tasks that will be executed as part of the job 49 | steps: 50 | - run: echo "🎉 The job was automatically triggered by a ${{ github.event_name }} event." 51 | - run: echo "🐧 This job is now running on a ${{ runner.os }} server hosted by GitHub!" 52 | - run: echo "🔎 The name of your branch is ${{ github.ref }} and your repository is ${{ github.repository }}." 53 | 54 | # First of all, we clone the repo using the `checkout` action. 55 | # Checks-out your repository under $GITHUB_WORKSPACE, so your job can access it 56 | - name: Checkout 57 | uses: actions/checkout@v2 58 | #- uses: actions/setup-python@v1 59 | # with: 60 | # python-version: '3.x' 61 | - run: echo "💡 The ${{ github.repository }} repository has been cloned to the runner." 62 | 63 | # We use the `arduino/setup-arduino-cli` action to install and 64 | # configure the Arduino CLI on the system. 65 | - name: Setup Arduino CLI 66 | uses: arduino/setup-arduino-cli@v1 67 | 68 | # We then install the platform, which one will be determined 69 | # dynamically by the build matrix. 70 | - name: Install platform 71 | run: | 72 | arduino-cli config init --additional-urls ${{ env.ARDUINO_BOARD_MANAGER_ADDITIONAL_URLS}} 73 | arduino-cli core update-index 74 | arduino-cli core install ${{ matrix.arduino-platform }} 75 | arduino-cli lib install "WiFiManager" 76 | echo "Current workspace: ${{ github.workspace }}" 77 | ls ${{ github.workspace }} 78 | 79 | # Finally, we compile the sketch, using the FQBN that was set 80 | # in the build matrix. 81 | - name: Compile Sketch 82 | run: arduino-cli compile --fqbn ${{ matrix.fqbn }} GoogleDocs 83 | 84 | - run: echo "🍏 This job's status is ${{ job.status }}." 85 | 86 | # Runs a single command using the runners shell 87 | #- name: pre-install 88 | # run: bash ./actions_install.sh 89 | 90 | # Runs a set of commands using the runners shell 91 | #- name: test 92 | # run: | 93 | # echo Add other actions to build, 94 | # python3 build_platform.py uno leonardo mega2560 zero esp8266 esp32 pico_rp2040 95 | 96 | 97 | -------------------------------------------------------------------------------- /.github/workflows/greetings.yml: -------------------------------------------------------------------------------- 1 | name: Greetings 2 | 3 | on: [pull_request, issues] 4 | 5 | jobs: 6 | greeting: 7 | runs-on: ubuntu-latest 8 | steps: 9 | - uses: actions/first-interaction@v1 10 | with: 11 | repo-token: ${{ secrets.GITHUB_TOKEN }} 12 | issue-message: 'Welcome to HTTPSRedirect! Please provide enough info to debug the issue.' 13 | pr-message: 'Welcome to HTTPSRedirect! Please stick to coding style and good programming practices.' 14 | 15 | -------------------------------------------------------------------------------- /.gitignore: -------------------------------------------------------------------------------- 1 | .vscode/ 2 | -------------------------------------------------------------------------------- /DebugMacros.h: -------------------------------------------------------------------------------- 1 | // Variadic macros used to print information in de-bugging mode 2 | // from LarryD, Arduino forum 3 | 4 | #pragma once 5 | // un-comment this line to print the debugging statements 6 | //#define DEBUG 7 | 8 | #ifdef DEBUG 9 | #define DPRINT(...) Serial.print(__VA_ARGS__) 10 | #define DPRINTLN(...) Serial.println(__VA_ARGS__) 11 | #else 12 | // define blank line 13 | #define DPRINT(...) 14 | #define DPRINTLN(...) 15 | #endif 16 | 17 | -------------------------------------------------------------------------------- /Extra/Contributors.txt: -------------------------------------------------------------------------------- 1 | Thank you to the following people for the generous contributions: 2 | 3 | 1. Bhavesh 4 | 2. David Truyens 5 | 3. Dash Electronics, Israel 6 | -------------------------------------------------------------------------------- /Extra/Test-REST-API-calendar.jpg: -------------------------------------------------------------------------------- https://raw.githubusercontent.com/electronicsguy/HTTPSRedirect/0415a49b42df3b5cdd176e10aad6d262d09e167f/Extra/Test-REST-API-calendar.jpg -------------------------------------------------------------------------------- /Extra/chart.jpg: -------------------------------------------------------------------------------- https://raw.githubusercontent.com/electronicsguy/HTTPSRedirect/0415a49b42df3b5cdd176e10aad6d262d09e167f/Extra/chart.jpg -------------------------------------------------------------------------------- /Extra/output.jpg: -------------------------------------------------------------------------------- https://raw.githubusercontent.com/electronicsguy/HTTPSRedirect/0415a49b42df3b5cdd176e10aad6d262d09e167f/Extra/output.jpg -------------------------------------------------------------------------------- /Extra/redirection.png: -------------------------------------------------------------------------------- https://raw.githubusercontent.com/electronicsguy/HTTPSRedirect/0415a49b42df3b5cdd176e10aad6d262d09e167f/Extra/redirection.png -------------------------------------------------------------------------------- /Extra/redirection.svg: -------------------------------------------------------------------------------- 1 | 2 | 3 | Follow-redirect logic:GETGET... GETPOSTGET... GETFinalResponse(endpoint) -------------------------------------------------------------------------------- /Extra/spreadsheet.jpg: -------------------------------------------------------------------------------- https://raw.githubusercontent.com/electronicsguy/HTTPSRedirect/0415a49b42df3b5cdd176e10aad6d262d09e167f/Extra/spreadsheet.jpg -------------------------------------------------------------------------------- /GoogleDocs.ino: -------------------------------------------------------------------------------- 1 | /* HTTPS on ESP8266 with follow redirects, chunked encoding support 2 | * Version 3.0 3 | * Author: Sujay Phadke 4 | * Github: @electronicsguy 5 | * Copyright (C) 2018 Sujay Phadke 6 | * All rights reserved. 7 | * 8 | * Example Arduino program 9 | */ 10 | 11 | #include 12 | #include "HTTPSRedirect.h" 13 | #include "DebugMacros.h" 14 | 15 | extern const char* ssid; 16 | extern const char* password; 17 | extern const char* host; 18 | extern const char *GScriptId; 19 | 20 | const int httpsPort = 443; 21 | 22 | // echo | openssl s_client -connect script.google.com:443 |& openssl x509 -fingerprint -noout 23 | const char* fingerprint = ""; 24 | //const uint8_t fingerprint[20] = {}; 25 | 26 | // Write to Google Spreadsheet 27 | String url = String("/macros/s/") + GScriptId + "/exec?value=Hello"; 28 | // Fetch Google Calendar events for 1 week ahead 29 | String url2 = String("/macros/s/") + GScriptId + "/exec?cal"; 30 | // Read from Google Spreadsheet 31 | String url3 = String("/macros/s/") + GScriptId + "/exec?read"; 32 | 33 | String payload_prefix = "{\"command\": \"appendRow\", \ 34 | \"sheet_name\": \"Sheet1\", \ 35 | \"values\": \""; 36 | String payload_suffix = "\"}"; 37 | String payload = ""; 38 | 39 | HTTPSRedirect* client = nullptr; 40 | // used to store the values of free stack and heap 41 | // before the HTTPSRedirect object is instantiated 42 | // so that they can be written to Google sheets 43 | // upon instantiation 44 | unsigned int free_heap_before = 0; 45 | unsigned int free_stack_before = 0; 46 | 47 | void setup() { 48 | Serial.begin(115200); 49 | Serial.flush(); 50 | 51 | free_heap_before = ESP.getFreeHeap(); 52 | free_stack_before = ESP.getFreeContStack(); 53 | Serial.printf("Free heap: %u\n", free_heap_before); 54 | Serial.printf("Free stack: %u\n", free_stack_before); 55 | 56 | Serial.println(); 57 | Serial.print("Connecting to wifi: "); 58 | Serial.println(ssid); 59 | // flush() is needed to print the above (connecting...) message reliably, 60 | // in case the wireless connection doesn't go through 61 | Serial.flush(); 62 | 63 | WiFi.begin(ssid, password); 64 | while (WiFi.status() != WL_CONNECTED) { 65 | delay(500); 66 | Serial.print("."); 67 | } 68 | Serial.println(""); 69 | Serial.println("WiFi connected"); 70 | Serial.println("IP address: "); 71 | Serial.println(WiFi.localIP()); 72 | 73 | // Use HTTPSRedirect class to create a new TLS connection 74 | client = new HTTPSRedirect(httpsPort); 75 | client->setInsecure(); 76 | client->setPrintResponseBody(true); 77 | client->setContentTypeHeader("application/json"); 78 | 79 | Serial.print("Connecting to "); 80 | Serial.println(host); 81 | 82 | // Try to connect for a maximum of 5 times 83 | bool flag = false; 84 | for (int i=0; i<5; i++){ 85 | int retval = client->connect(host, httpsPort); 86 | if (retval == 1) { 87 | flag = true; 88 | break; 89 | } 90 | else 91 | Serial.println("Connection failed. Retrying..."); 92 | } 93 | 94 | if (!flag){ 95 | Serial.print("Could not connect to server: "); 96 | Serial.println(host); 97 | Serial.println("Exiting..."); 98 | return; 99 | } 100 | 101 | /* 102 | if (client->setFingerprint(fingerprint)) { 103 | Serial.println("Certificate match."); 104 | } else { 105 | Serial.println("Certificate mis-match"); 106 | } 107 | */ 108 | 109 | // Send memory data to Google Sheets 110 | payload = payload_prefix + free_heap_before + "," + free_stack_before + payload_suffix; 111 | client->POST(url2, host, payload, false); 112 | payload = payload_prefix + ESP.getFreeHeap() + "," + ESP.getFreeContStack() + payload_suffix; 113 | client->POST(url2, host, payload, false); 114 | 115 | // Note: setup() must finish within approx. 1s, or the the watchdog timer 116 | // will reset the chip. Hence don't put too many requests in setup() 117 | // ref: https://github.com/esp8266/Arduino/issues/34 118 | 119 | Serial.println("\nGET: Write into cell 'A1'"); 120 | Serial.println("========================="); 121 | 122 | // fetch spreadsheet data 123 | client->GET(url, host); 124 | 125 | // Send memory data to Google Sheets 126 | payload = payload_prefix + ESP.getFreeHeap() + "," + ESP.getFreeContStack() + payload_suffix; 127 | client->POST(url2, host, payload, false); 128 | 129 | Serial.println("\nGET: Fetch Google Calendar Data:"); 130 | Serial.println("================================"); 131 | 132 | // fetch spreadsheet data 133 | client->GET(url2, host); 134 | 135 | // Send memory data to Google Sheets 136 | payload = payload_prefix + ESP.getFreeHeap() + "," + ESP.getFreeContStack() + payload_suffix; 137 | client->POST(url2, host, payload, false); 138 | 139 | Serial.println("\nSeries of GET and POST requests"); 140 | Serial.println("==============================="); 141 | 142 | Serial.printf("Free heap: %u\n", ESP.getFreeHeap()); 143 | Serial.printf("Free stack: %u\n", ESP.getFreeContStack()); 144 | 145 | // delete HTTPSRedirect object 146 | delete client; 147 | client = nullptr; 148 | } 149 | 150 | void loop() { 151 | static int error_count = 0; 152 | static int connect_count = 0; 153 | const unsigned int MAX_CONNECT = 20; 154 | static bool flag = false; 155 | //Serial.printf("Free heap: %u\n", ESP.getFreeHeap()); 156 | //Serial.printf("Free stack: %u\n", ESP.getFreeContStack()); 157 | 158 | if (!flag){ 159 | free_heap_before = ESP.getFreeHeap(); 160 | free_stack_before = ESP.getFreeContStack(); 161 | client = new HTTPSRedirect(httpsPort); 162 | client->setInsecure(); 163 | flag = true; 164 | client->setPrintResponseBody(true); 165 | client->setContentTypeHeader("application/json"); 166 | } 167 | 168 | if (client != nullptr){ 169 | if (!client->connected()){ 170 | client->connect(host, httpsPort); 171 | payload = payload_prefix + free_heap_before + "," + free_stack_before + payload_suffix; 172 | client->POST(url2, host, payload, false); 173 | } 174 | } 175 | else{ 176 | DPRINTLN("Error creating client object!"); 177 | error_count = 5; 178 | } 179 | 180 | if (connect_count > MAX_CONNECT){ 181 | //error_count = 5; 182 | connect_count = 0; 183 | flag = false; 184 | delete client; 185 | return; 186 | } 187 | 188 | Serial.println("GET Data from cell 'A1':"); 189 | if (client->GET(url3, host)){ 190 | ++connect_count; 191 | } 192 | else{ 193 | ++error_count; 194 | DPRINT("Error-count while connecting: "); 195 | DPRINTLN(error_count); 196 | } 197 | 198 | Serial.println("POST append memory data to spreadsheet:"); 199 | payload = payload_prefix + ESP.getFreeHeap() + "," + ESP.getFreeContStack() + payload_suffix; 200 | if(client->POST(url2, host, payload)){ 201 | ; 202 | } 203 | else{ 204 | ++error_count; 205 | DPRINT("Error-count while connecting: "); 206 | DPRINTLN(error_count); 207 | } 208 | 209 | /* 210 | if (!(client.reConnectFinalEndpoint())){ 211 | ++error_count; 212 | DPRINT("Error-count while connecting: "); 213 | DPRINTLN(error_count); 214 | } 215 | else 216 | error_countunt = 0; 217 | */ 218 | 219 | if (error_count > 3){ 220 | Serial.println("Halting processor..."); 221 | delete client; 222 | client = nullptr; 223 | Serial.printf("Final free heap: %u\n", ESP.getFreeHeap()); 224 | Serial.printf("Final stack: %u\n", ESP.getFreeContStack()); 225 | Serial.flush(); 226 | ESP.deepSleep(0); 227 | } 228 | 229 | // In my testing on a ESP-01, a delay of less than 1500 resulted 230 | // in a crash and reboot after about 50 loop runs. 231 | delay(4000); 232 | 233 | } 234 | -------------------------------------------------------------------------------- /GoogleScript.gs: -------------------------------------------------------------------------------- 1 | // Created by Sujay S. Phadke, 2017 2 | // All Rights Reserved. 3 | // Github: https://github.com/electronicsguy 4 | // 5 | // Read/Write to Google Sheets using REST API. 6 | // Can be used with ESP8266 & other embedded IoT devices. 7 | // 8 | // Use this file with the ESP8266 library HTTPSRedirect 9 | // 10 | // doGet() and doPost() need the spreadsheet ID. Cannot use "active spreadsheet" here since 11 | // the device can operate without the spreadsheet even being open. 12 | // http://stackoverflow.com/questions/4024271/rest-api-best-practices-where-to-put-parameters 13 | // http://trevorfox.com/2015/03/rest-api-with-google-apps-script 14 | 15 | // Similar API docs: 16 | // https://gspread.readthedocs.org/en/latest/ 17 | // https://smartsheet-platform.github.io/api-docs/#versioning-and-changes 18 | // http://search.cpan.org/~jmcnamara/Excel-Writer-XLSX/lib/Excel/Writer/XLSX.pm 19 | 20 | // http://forum.espruino.com/conversations/269510/ 21 | // http://stackoverflow.com/questions/34691425/difference-between-getvalue-and-getdisplayvalue-on-google-app-script 22 | // http://ramblings.mcpher.com/Home/excelquirks/gooscript/optimize 23 | 24 | // Things to remember with getValue() object format: 25 | // 1. Partial dates or times-only will be replaced with a full date + time, probably in the 26 | // year 1989. Like this: Sat Dec 30 1899 08:09:00 GMT-0500 (EST) 27 | // 2. Dollar ($) currency symbol will be absent if cell contains currency. 28 | // This may be locale-dependent. 29 | // 3. Scientific notation will be replaced by decimal numbers like this: 0.0000055 30 | 31 | // Script examples 32 | // https://developers.google.com/adwords/scripts/docs/examples/spreadsheetapp 33 | 34 | var SS = SpreadsheetApp.openById('1j5UX_r9JBG_qLsKYpLnlgqdZgXSkF1VC8L_mt7iAhgI'); 35 | var sheet = SS.getSheetByName('Sheet1'); 36 | var str = ""; 37 | 38 | function onOpen(){ 39 | var ui = SpreadsheetApp.getUi(); 40 | ui.createMenu('ESP8266 Logging') 41 | .addItem('Clear', 'Clear') 42 | .addToUi(); 43 | } 44 | 45 | function Clear(){ 46 | sheet.deleteRows(4, sheet.getLastRow()); 47 | SS.toast('Chart cleared', 'ESP8266 logging', 5); 48 | } 49 | 50 | function doPost(e) { 51 | 52 | var parsedData; 53 | var result = {}; 54 | 55 | try { 56 | parsedData = JSON.parse(e.postData.contents); 57 | } 58 | catch(f){ 59 | return ContentService.createTextOutput("Error in parsing request body: " + f.message); 60 | } 61 | 62 | if (parsedData !== undefined){ 63 | // Common items first 64 | // data format: 0 = display value(literal), 1 = object value 65 | var flag = parsedData.format; 66 | 67 | if (flag === undefined){ 68 | flag = 0; 69 | } 70 | 71 | switch (parsedData.command) { 72 | case "appendRow": 73 | var tmp = SS.getSheetByName(parsedData.sheet_name); 74 | var nextFreeRow = tmp.getLastRow() + 1; 75 | var dataArr = parsedData.values.split(","); 76 | 77 | tmp.appendRow(dataArr); 78 | 79 | str = "Success"; 80 | SpreadsheetApp.flush(); 81 | break; 82 | 83 | 84 | } 85 | 86 | return ContentService.createTextOutput(str); 87 | } // endif (parsedData !== undefined) 88 | 89 | else{ 90 | return ContentService.createTextOutput("Error! Request body empty or in incorrect format."); 91 | } 92 | 93 | 94 | } 95 | 96 | 97 | function doGet(e){ 98 | 99 | var val = e.parameter.value; 100 | var cal = e.parameter.cal; 101 | var read = e.parameter.read; 102 | 103 | if (cal !== undefined){ 104 | return ContentService.createTextOutput(GetEventsOneWeek()); 105 | } 106 | 107 | if (read !== undefined){ 108 | var now = Utilities.formatDate(new Date(), "EST", "yyyy-MM-dd'T'hh:mm a'Z'").slice(11,19); 109 | sheet.getRange('D1').setValue(now); 110 | var count = (sheet.getRange('C1').getValue()) + 1; 111 | sheet.getRange('C1').setValue(count); 112 | return ContentService.createTextOutput(sheet.getRange('A1').getValue()); 113 | } 114 | 115 | if (e.parameter.value === undefined) 116 | return ContentService.createTextOutput("No value passed as argument to script Url."); 117 | 118 | var range = sheet.getRange('A1'); 119 | var retval = range.setValue(val).getValue(); 120 | var now = Utilities.formatDate(new Date(), "EST", "yyyy-MM-dd'T'hh:mm a'Z'").slice(11,19); 121 | sheet.getRange('B1').setValue(now); 122 | sheet.getRange('C1').setValue('0'); 123 | 124 | if (retval == e.parameter.value) 125 | return ContentService.createTextOutput("Successfully wrote: " + e.parameter.value + "\ninto spreadsheet."); 126 | else 127 | return ContentService.createTextOutput("Unable to write into spreadsheet.\nCheck authentication and make sure the cursor is not on cell 'A1'." + retval + ' ' + e.parameter.value); 128 | } 129 | 130 | function GetEventsOneWeek(){ 131 | var Cal = CalendarApp.getCalendarsByName('Test REST API')[0]; 132 | // Need to create 2 separate Date() objects. Cannot do 'OneWeekFromNow = Nowjs' to 133 | // simply get it's value and use that later without modifying 'Now' 134 | // since in JS, an object is automatically passed by reference 135 | var Now = new Date(); 136 | var OneWeekFromNow = new Date(); 137 | OneWeekFromNow.setDate(Now.getDate() + 7); 138 | //Logger.log(Now); 139 | //Logger.log(OneWeekFromNow); 140 | var events = Cal.getEvents(Now, OneWeekFromNow); 141 | //Logger.log(events.length); 142 | var str = '\nEvent Title,\tDescription,\tRecurring?,\tAll-day?,\tFirst Reminder (in minutes before event)\n'; 143 | for (var i = 0; i < events.length; i++){ 144 | str += events[i].getTitle() + ',\t' + events[i].getDescription() + ',\t' + events[i].isRecurringEvent() + ',\t' + events[i].isAllDayEvent() + ',\t' + events[i].getPopupReminders()[0]; 145 | str += '\n'; 146 | } 147 | //Logger.log(str); 148 | return str; 149 | } 150 | -------------------------------------------------------------------------------- /HTTPSRedirect.cpp: -------------------------------------------------------------------------------- 1 | /* HTTPS on ESP8266 with follow redirects, chunked encoding support 2 | * Version 2.1 3 | * Author: Sujay Phadke 4 | * Github: @electronicsguy 5 | * Copyright (C) 2017 Sujay Phadke 6 | * All rights reserved. 7 | * 8 | */ 9 | 10 | #include "HTTPSRedirect.h" 11 | #include "DebugMacros.h" 12 | 13 | HTTPSRedirect::HTTPSRedirect(const int p=443) : _httpsPort(p){ 14 | Init(); 15 | } 16 | 17 | HTTPSRedirect::~HTTPSRedirect(){ 18 | } 19 | 20 | void HTTPSRedirect::Init(void){ 21 | _keepAlive = true; 22 | _printResponseBody = false; 23 | _maxRedirects = 10; 24 | _contentTypeHeader = "application/x-www-form-urlencoded"; 25 | } 26 | 27 | // This is the main function which is similar to the method 28 | // print() from WifiClient or WifiClientSecure 29 | bool HTTPSRedirect::printRedir(void){ 30 | unsigned int httpStatus; 31 | 32 | // Check if connection to host is alive 33 | if (!connected()){ 34 | Serial.println("Error! Not connected to host."); 35 | return false; 36 | } 37 | 38 | // Clear the input stream of any junk data before making the request 39 | while(available()) 40 | read(); 41 | 42 | // Create HTTP/1.1 compliant request string 43 | // HTTP/1.1 complaint request packet must exist 44 | 45 | DPRINTLN(_Request); 46 | 47 | // Make the actual HTTPS request using the method 48 | // print() from the WifiClientSecure class 49 | // Make sure the input stream is cleared (as above) before making the call 50 | print(_Request); 51 | 52 | // Read HTTP Response Status lines 53 | while (connected()) { 54 | 55 | httpStatus = getResponseStatus(); 56 | 57 | // Only some HTTP response codes are checked for 58 | // http://www.restapitutorial.com/httpstatuscodes.html 59 | switch (httpStatus){ 60 | // Success. Fetch final response body 61 | case 200: 62 | case 201: 63 | { 64 | // final header is discarded 65 | fetchHeader(); 66 | 67 | #ifdef EXTRA_FNS 68 | printHeaderFields(); 69 | #endif 70 | 71 | if (_hF.transferEncoding == "chunked") 72 | fetchBodyChunked(); 73 | else 74 | fetchBodyUnChunked(_hF.contentLength); 75 | 76 | return true; 77 | } 78 | break; 79 | 80 | case 301: 81 | case 302: 82 | { 83 | // Get re-direction URL from the 'Location' field in the header 84 | if (getLocationURL()){ 85 | //stop(); // may not be required 86 | 87 | _myResponse.redirected = true; 88 | 89 | // Make a new connection to the re-direction server 90 | if (!connect(_redirHost.c_str(), _httpsPort)) { 91 | Serial.println("Connection to re-directed URL failed!"); 92 | return false; 93 | } 94 | 95 | // Recursive call to the requested URL on the server 96 | return printRedir(); 97 | 98 | } 99 | else{ 100 | Serial.println("Unable to retrieve redirection URL!"); 101 | return false; 102 | 103 | } 104 | } 105 | break; 106 | 107 | default: 108 | Serial.print("Error with request. Response status code: "); 109 | Serial.println(httpStatus); 110 | return false; 111 | break; 112 | } // end of switch 113 | 114 | } // end of while 115 | 116 | return false; 117 | 118 | } 119 | 120 | // Create a HTTP GET request packet 121 | // GET headers must be terminated with a "\r\n\r\n" 122 | // http://stackoverflow.com/questions/6686261/what-at-the-bare-minimum-is-required-for-an-http-request 123 | void HTTPSRedirect::createGetRequest(const String& url, const char* host){ 124 | _Request = String("GET ") + url + " HTTP/1.1\r\n" + 125 | "Host: " + host + "\r\n" + 126 | "User-Agent: ESP8266\r\n" + 127 | (_keepAlive ? "" : "Connection: close\r\n") + 128 | "\r\n\r\n"; 129 | 130 | return; 131 | } 132 | 133 | // Create a HTTP POST request packet 134 | // POST headers must be terminated with a "\r\n\r\n" 135 | // POST requests have 1 single blank like between the end of the header fields and the body payload 136 | void HTTPSRedirect::createPostRequest(const String& url, const char* host, const String& payload){ 137 | // Content-Length is mandatory in POST requests 138 | // Body content will include payload and a newline character 139 | unsigned int len = payload.length() + 1; 140 | 141 | _Request = String("POST ") + url + " HTTP/1.1\r\n" + 142 | "Host: " + host + "\r\n" + 143 | "User-Agent: ESP8266\r\n" + 144 | (_keepAlive ? "" : "Connection: close\r\n") + 145 | "Content-Type: " + _contentTypeHeader + "\r\n" + 146 | "Content-Length: " + len + "\r\n" + 147 | "\r\n" + 148 | payload + 149 | "\r\n\r\n"; 150 | 151 | return; 152 | } 153 | 154 | 155 | bool HTTPSRedirect::getLocationURL(void){ 156 | 157 | bool flag; 158 | 159 | // Keep reading from the input stream till we get to 160 | // the location field in the header 161 | flag = find("Location: "); 162 | 163 | if (flag){ 164 | // Skip URI protocol (http, https, etc. till '//') 165 | // This assumes that the location field will be containing 166 | // a URL of the form: http:/// 167 | readStringUntil('/'); 168 | readStringUntil('/'); 169 | // get hostname 170 | _redirHost = readStringUntil('/'); 171 | // get remaining url 172 | _redirUrl = String('/') + readStringUntil('\n'); 173 | } 174 | else{ 175 | DPRINT("No valid 'Location' field found in header!"); 176 | } 177 | 178 | // Create a GET request for the new location 179 | createGetRequest(_redirUrl, _redirHost.c_str()); 180 | 181 | DPRINT("_redirHost: "); 182 | DPRINTLN(_redirHost); 183 | DPRINT("_redirUrl: "); 184 | DPRINTLN(_redirUrl); 185 | 186 | return flag; 187 | } 188 | 189 | void HTTPSRedirect::fetchHeader(void){ 190 | String line = ""; 191 | int pos = -1; 192 | int pos2 = -1; 193 | int pos3 = -1; 194 | 195 | _hF.transferEncoding = ""; 196 | _hF.contentLength = 0; 197 | 198 | #ifdef EXTRA_FNS 199 | _hF.contentType = ""; 200 | #endif 201 | 202 | while (connected()) { 203 | line = readStringUntil('\n'); 204 | 205 | DPRINTLN(line); 206 | 207 | // HTTP headers are terminated by a CRLF ('\r\n') 208 | // Hence the final line will contain only '\r' 209 | // since we have already till the end ('\n') 210 | if (line == "\r") 211 | break; 212 | 213 | if (pos < 0){ 214 | pos = line.indexOf("Transfer-Encoding: "); 215 | if (!pos) 216 | // get string & remove trailing '\r' character to facilitate string comparisons 217 | _hF.transferEncoding = line.substring(19, line.length()-1); 218 | } 219 | if (pos2 < 0){ 220 | pos2 = line.indexOf("Content-Length: "); 221 | if (!pos2) 222 | _hF.contentLength = line.substring(16).toInt(); 223 | } 224 | #ifdef EXTRA_FNS 225 | if (pos3 < 0){ 226 | pos3 = line.indexOf("Content-Type: "); 227 | if (!pos3) 228 | // get string & remove trailing '\r' character to facilitate string comparisons 229 | _hF.contentType = line.substring(14, line.length()-1); 230 | } 231 | #endif 232 | 233 | } 234 | 235 | return; 236 | } 237 | 238 | void HTTPSRedirect::fetchBodyUnChunked(unsigned len){ 239 | String line; 240 | DPRINTLN("Body:"); 241 | 242 | while ((connected()) && (len > 0)) { 243 | line = readStringUntil('\n'); 244 | len -= line.length(); 245 | // Content length will include all '\n' terminating characters 246 | // Decrement once more to account for the '\n' line ending character 247 | --len; 248 | 249 | if (_printResponseBody) 250 | Serial.println(line); 251 | 252 | _myResponse.body += line; 253 | _myResponse.body += '\n'; 254 | 255 | } 256 | } 257 | 258 | // Ref: http://mihai.ibanescu.net/chunked-encoding-and-python-requests 259 | // http://fssnip.net/2t 260 | void HTTPSRedirect::fetchBodyChunked(void){ 261 | String line; 262 | int chunkSize; 263 | 264 | while (connected()){ 265 | line = readStringUntil('\n'); 266 | 267 | // Skip any empty lines 268 | if (line == "\r") 269 | continue; 270 | 271 | // Chunk sizes are in hexadecimal so convert to integer 272 | chunkSize = (uint32_t) strtol((const char *) line.c_str(), NULL, 16); 273 | DPRINT("Chunk Size: "); 274 | DPRINTLN(chunkSize); 275 | 276 | // Terminating chunk is of size 0 277 | if (chunkSize == 0) 278 | break; 279 | 280 | while (chunkSize > 0){ 281 | line = readStringUntil('\n'); 282 | if (_printResponseBody) 283 | Serial.println(line); 284 | 285 | _myResponse.body += line; 286 | _myResponse.body += '\n'; 287 | 288 | chunkSize -= line.length(); 289 | // The line above includes the '\r' character 290 | // which is not part of chunk size, so account for it 291 | --chunkSize; 292 | } 293 | 294 | // Skip over chunk trailer 295 | 296 | } 297 | 298 | return; 299 | 300 | } 301 | 302 | unsigned int HTTPSRedirect::getResponseStatus(void){ 303 | // Read response status line 304 | // ref: https://www.tutorialspoint.com/http/http_responses.htm 305 | 306 | unsigned int statusCode; 307 | String reasonPhrase; 308 | String line; 309 | 310 | unsigned int pos = -1; 311 | unsigned int pos2 = -1; 312 | 313 | // Skip any empty lines 314 | do{ 315 | line = readStringUntil('\n'); 316 | }while(line.length() == 0); 317 | 318 | pos = line.indexOf("HTTP/1.1 "); 319 | pos2 = line.indexOf(" ", 9); 320 | 321 | if (!pos){ 322 | statusCode = line.substring(9, pos2).toInt(); 323 | reasonPhrase = line.substring(pos2+1, line.length()-1); 324 | } 325 | else{ 326 | DPRINTLN("Error! No valid Status Code found in HTTP Response."); 327 | statusCode = 0; 328 | reasonPhrase = ""; 329 | } 330 | 331 | _myResponse.statusCode = statusCode; 332 | _myResponse.reasonPhrase = reasonPhrase; 333 | 334 | DPRINT("Status code: "); 335 | DPRINTLN(statusCode); 336 | DPRINT("Reason phrase: "); 337 | DPRINTLN(reasonPhrase); 338 | 339 | return statusCode; 340 | } 341 | 342 | bool HTTPSRedirect::GET(const String& url, const char* host){ 343 | return GET(url, host, _printResponseBody); 344 | } 345 | 346 | bool HTTPSRedirect::GET(const String& url, const char* host, const bool& disp){ 347 | bool retval; 348 | bool oldval; 349 | 350 | // set _printResponseBody temporarily to argument passed 351 | oldval = _printResponseBody; 352 | _printResponseBody = disp; 353 | 354 | // redirected Host and Url need to be initialized in case a 355 | // reConnectFinalEndpoint() request is made after an initial request 356 | // which did not have redirection 357 | _redirHost = host; 358 | _redirUrl = url; 359 | 360 | InitResponse(); 361 | 362 | // Create request packet 363 | createGetRequest(url, host); 364 | 365 | // Calll request handler 366 | retval = printRedir(); 367 | 368 | _printResponseBody = oldval; 369 | return retval; 370 | } 371 | 372 | bool HTTPSRedirect::POST(const String& url, const char* host, const String& payload){ 373 | return POST(url, host, payload, _printResponseBody); 374 | } 375 | 376 | bool HTTPSRedirect::POST(const String& url, const char* host, const String& payload, const bool& disp){ 377 | bool retval; 378 | bool oldval; 379 | 380 | // set _printResponseBody temporarily to argument passed 381 | oldval = _printResponseBody; 382 | _printResponseBody = disp; 383 | 384 | // redirected Host and Url need to be initialized in case a 385 | // reConnectFinalEndpoint() request is made after an initial request 386 | // which did not have redirection 387 | _redirHost = host; 388 | _redirUrl = url; 389 | 390 | InitResponse(); 391 | 392 | // Create request packet 393 | createPostRequest(url, host, payload); 394 | 395 | // Call request handler 396 | retval = printRedir(); 397 | 398 | _printResponseBody = oldval; 399 | return retval; 400 | } 401 | 402 | void HTTPSRedirect::InitResponse(void){ 403 | // Init response data 404 | _myResponse.body = ""; 405 | _myResponse.statusCode = 0; 406 | _myResponse.reasonPhrase = ""; 407 | _myResponse.redirected = false; 408 | } 409 | 410 | int HTTPSRedirect::getStatusCode(void){ 411 | return _myResponse.statusCode; 412 | } 413 | 414 | String HTTPSRedirect::getReasonPhrase(void){ 415 | return _myResponse.reasonPhrase; 416 | } 417 | 418 | String HTTPSRedirect::getResponseBody(void){ 419 | return _myResponse.body; 420 | } 421 | 422 | void HTTPSRedirect::setPrintResponseBody(bool disp){ 423 | _printResponseBody = disp; 424 | } 425 | 426 | void HTTPSRedirect::setMaxRedirects(const unsigned int n){ 427 | _maxRedirects = n; // to-do: use this in code above 428 | } 429 | 430 | void HTTPSRedirect::setContentTypeHeader(const char *type){ 431 | _contentTypeHeader = type; 432 | } 433 | 434 | #ifdef OPTIMIZE_SPEED 435 | bool HTTPSRedirect::reConnectFinalEndpoint(void){ 436 | // disconnect if connection already exists 437 | if (connected()) 438 | stop(); 439 | 440 | DPRINT("_redirHost: "); 441 | DPRINTLN(_redirHost); 442 | DPRINT("_redirUrl: "); 443 | DPRINTLN(_redirUrl); 444 | 445 | // Connect to stored final endpoint 446 | if (!connect(_redirHost.c_str(), _httpsPort)) { 447 | DPRINTLN("Connection to final URL failed!"); 448 | return false; 449 | } 450 | 451 | // Valid request packed must already be 452 | // present at this point in the member variable _Request 453 | // from the previous GET() or POST() request 454 | 455 | // Make call to final endpoint 456 | return printRedir(); 457 | } 458 | #endif 459 | 460 | #ifdef EXTRA_FNS 461 | void HTTPSRedirect::fetchBodyRaw(void){ 462 | String line; 463 | 464 | while (connected()){ 465 | line = readStringUntil('\n'); 466 | if (_printResponseBody) 467 | Serial.println(line); 468 | 469 | _myResponse.body += line; 470 | _myResponse.body += '\n'; 471 | } 472 | } 473 | 474 | void HTTPSRedirect::printHeaderFields(void){ 475 | DPRINT("Transfer Encoding: "); 476 | DPRINTLN(_hF.transferEncoding); 477 | DPRINT("Content Length: "); 478 | DPRINTLN(_hF.contentLength); 479 | DPRINT("Content Type: "); 480 | DPRINTLN(_hF.contentType); 481 | } 482 | #endif 483 | 484 | -------------------------------------------------------------------------------- /HTTPSRedirect.h: -------------------------------------------------------------------------------- 1 | /* HTTPS on ESP8266 with follow redirects, chunked encoding support 2 | * Version 2.1 3 | * Author: Sujay Phadke 4 | * Github: @electronicsguy 5 | * Copyright (C) 2017 Sujay Phadke 6 | * All rights reserved. 7 | * 8 | */ 9 | #pragma once 10 | #include 11 | 12 | // Un-comment for extra functionality 13 | //#define EXTRA_FNS 14 | #define OPTIMIZE_SPEED 15 | 16 | class HTTPSRedirect : public WiFiClientSecure { 17 | private: 18 | const int _httpsPort; 19 | bool _keepAlive; 20 | String _redirUrl; 21 | String _redirHost; 22 | unsigned int _maxRedirects; // to-do 23 | const char* _contentTypeHeader; 24 | 25 | struct headerFields{ 26 | String transferEncoding; 27 | unsigned int contentLength; 28 | #ifdef EXTRA_FNS 29 | String contentType; 30 | #endif 31 | }; 32 | 33 | headerFields _hF; 34 | 35 | String _Request; 36 | 37 | struct Response{ 38 | int statusCode; 39 | String reasonPhrase; 40 | bool redirected; 41 | String body; 42 | }; 43 | 44 | Response _myResponse; 45 | bool _printResponseBody; 46 | 47 | void Init(void); 48 | bool printRedir(void); 49 | void fetchHeader(void); 50 | bool getLocationURL(void); 51 | void fetchBodyUnChunked(unsigned); 52 | void fetchBodyChunked(void); 53 | unsigned int getResponseStatus(void); 54 | void InitResponse(void); 55 | void createGetRequest(const String&, const char*); 56 | void createPostRequest(const String&, const char*, const String&); 57 | 58 | #ifdef EXTRA_FNS 59 | void fetchBodyRaw(void); 60 | void printHeaderFields(void); 61 | #endif 62 | 63 | public: 64 | HTTPSRedirect(const int); 65 | ~HTTPSRedirect(); 66 | 67 | bool GET(const String&, const char*); 68 | bool GET(const String&, const char*, const bool&); 69 | bool POST(const String&, const char*, const String&); 70 | bool POST(const String&, const char*, const String&, const bool&); 71 | 72 | int getStatusCode(void); 73 | String getReasonPhrase(void); 74 | String getResponseBody(void); 75 | 76 | void setPrintResponseBody(bool); 77 | void setMaxRedirects(const unsigned int); 78 | 79 | void setContentTypeHeader(const char *); 80 | #ifdef OPTIMIZE_SPEED 81 | bool reConnectFinalEndpoint(void); 82 | #endif 83 | 84 | }; 85 | 86 | -------------------------------------------------------------------------------- /HTTPSRedirect.ino: -------------------------------------------------------------------------------- 1 | // The file exists only to satisfy the requirement of arduino-cli 2 | // https://github.com/arduino/arduino-cli/issues/765 3 | // It needs the main compiled file to have the same name as the repo 4 | 5 | -------------------------------------------------------------------------------- /LICENSE: -------------------------------------------------------------------------------- 1 | GNU AFFERO GENERAL PUBLIC LICENSE 2 | Version 3, 19 November 2007 3 | 4 | Copyright (C) 2007 Free Software Foundation, Inc. 5 | Everyone is permitted to copy and distribute verbatim copies 6 | of this license document, but changing it is not allowed. 7 | 8 | Preamble 9 | 10 | The GNU Affero General Public License is a free, copyleft license for 11 | software and other kinds of works, specifically designed to ensure 12 | cooperation with the community in the case of network server software. 13 | 14 | The licenses for most software and other practical works are designed 15 | to take away your freedom to share and change the works. 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If not, see . 647 | 648 | Also add information on how to contact you by electronic and paper mail. 649 | 650 | If your software can interact with users remotely through a computer 651 | network, you should also make sure that it provides a way for users to 652 | get its source. For example, if your program is a web application, its 653 | interface could display a "Source" link that leads users to an archive 654 | of the code. There are many ways you could offer source, and different 655 | solutions will be better for different programs; see section 13 for the 656 | specific requirements. 657 | 658 | You should also get your employer (if you work as a programmer) or school, 659 | if any, to sign a "copyright disclaimer" for the program, if necessary. 660 | For more information on this, and how to apply and follow the GNU AGPL, see 661 | . 662 | -------------------------------------------------------------------------------- /README.md: -------------------------------------------------------------------------------- 1 | [![CI](https://github.com/electronicsguy/HTTPSRedirect/actions/workflows/build.yml/badge.svg)](https://github.com/electronicsguy/HTTPSRedirect/actions/workflows/build.yml) 2 | [![License: AGPL v3](https://img.shields.io/badge/License-AGPL%20v3-blue.svg)](https://www.gnu.org/licenses/agpl-3.0) 3 | 4 | # HTTPS Redirect 5 | ## A library for seamless data logging, communication and control for Internet of Things (focus: ESP8266, ESP32) 6 | This library extends the *WiFiClientSecure* library ([Ivan-github](https://github.com/esp8266/Arduino/blob/master/libraries/ESP8266WiFi/src/WiFiClientSecure.h)). 7 | *HTTPSRedirect* uses the header information in the server's reply to a HTTP *GET* or *POST* request, and follows the re-direction URL by making another suitable *GET* request. In many cases, it is this re-directed URL which would present the final data that was required. 8 | 9 | **HTTPSRedirect implements a novel HTTP client with *follow-redirects* which can directly work with many web services (including Google Sheets, Calendar, Drive) without the need for 3rd party services like IFTTT, Temboo, Pushingbox, Thingspeak, Xively, etc.** 10 | 11 | Version 2 of *HTTPSRedirect* has been completely rewritten for increased functionality, seamless library calls and maximizing performance. 12 | 13 | ## Sec. I Major features in Version 2 14 | [enhancements] 15 | * Implements a detailed HTTP Client 16 | * Implements *GET* and *POST* requests according to HTTP/1.1 specificaton 17 | * Handles identity, chunked and raw transfer encoding in the response body 18 | * Generic enough to follow as many number of redirections as required 19 | * Generic enough to connect to any server, not just Google Docs 20 | * Various performance improvements 21 | 22 | [bug fixes] 23 | * Correctly parses HTTP status codes and calculates transfer chunk sizes 24 | 25 | ## Sec. II *HTTPSRedirect* Library API 26 |

27 | 28 | *HTTPSRedirect* is generic enough to be used as a standard HTTP/SSL client, even when the server has no redirection. Redirection logic is explained in the figure above. In case of a server using redirection (ie: 'Location' field in the first response header), the library will automatically follow the target URL(s) till it hits the final endpoint for the final response. 29 | 30 | ### Sec. II(a) *HTTPSRedirect* Initialization: 31 | Initialize a new *HTTPSRedirect* variable or object using either of these constructors: 32 | ```C++ 33 | HTTPSRedirect(void); 34 | HTTPSRedirect(const int& p); 35 | ``` 36 | where *p* denotes the HTTPS port to be used (default is 443). 37 | 38 | After initialization, use the method: 39 | ```C++ 40 | void setPrintResponseBody(bool); 41 | ``` 42 | to decide if you want the endpoint response body to be printed or not on the Serial output. If not printed to Serial output, it can be read using the method `getResponseBody()` described below. 43 | 44 | ### Sec. II(b) *HTTPSRedirect* methods: 45 | A *GET* request can be made by calling the following methods: 46 | 47 | ```C++ 48 | bool GET(const String& url, const char* host); 49 | bool GET(const String& url, const char* host, const bool& disp); 50 | ``` 51 | Arguments: 52 | *host* specifies the target server hostname and *url* specifies the specific URL for that host. 53 | 54 | A *POST* request can be made by calling the following methods: 55 | ```C++ 56 | bool POST(const String& url, const char* host, const String& payload); 57 | bool POST(const String& url, const char* host, const String& payload, const bool& disp); 58 | ``` 59 | Arguments: 60 | *host* specifies the target server hostname and *url* specifies the specific URL for that host. *payload* is a string containing the body of the POST request. 61 | 62 | (Optional) *disp* (boolean) temporarily overrides the value set by `printResponseBody()`. 63 | 64 | In both cases, the return value specifies if the request was made successfully or no. If an error occured, the final HTTP Status code and Reason phrase can be obtained via the methods: 65 | ```C++ 66 | int getStatusCode(void); 67 | String getReasonPhrase(void); 68 | ``` 69 | 70 | If the request was successful, the endpoint response can be obtained as a string using the method: 71 | ```C++ 72 | String getResponseBody(void); 73 | ``` 74 | ## Sec. III Features and Notes: 75 | ### Sec. III(a) Optimize Speed 76 | Most of the string arguments are passed by reference (or char \*) to avoid inefficient calls to the copy constructor. In case of redirection, it is possible that a repeated operation needs to be made, which results in the same request being made to the endpoint everytime. In such cases, a special method is provided to speed up the process: 77 | ```C++ 78 | bool HTTPSRedirect::reConnectFinalEndpoint(void); 79 | ``` 80 | *reConnectFinalEndpoint*, as the name implies, will directly reconnect to the last endpoint stored from previous requests. It'll return the response as per the data provided by the server. Hence, all the steps to compute the endpoint are avoided, speeding up the response rate. You can disable this by commenting out the `#define OPTIMIZE_SPEED` declaration within HTTPSRedirect.h. 81 | 82 | ### Sec. III(b) Extra functions 83 | These methods are not included by default to minimize the memory footprint: 84 | ```C++ 85 | void fetchBodyRaw(void); 86 | void printHeaderFields(void); 87 | ``` 88 | To enable them, uncomment this declaration within HTTPSRedirect.h `#define EXTRA_FNS`. 89 | Note: `fetchBodyRaw()` is still unimplemented. `printHeaderFields()` works in debugging mode (described below) to print some of the relevant header fields. 90 | 91 | ### Sec. III(c) Debugging 92 | *HTTPSRedirect* supports a debugging mode for developers. This prints out extra debugging information to the Serial output when enabled. To enable, uncomment this line within DebugMacros.h: `#define DEBUG`. 93 | 94 | ### Sec. III(d) SSL Certificates 95 | WiFiClientSecure supports TLS v1.2 and X.509 certificate fingerprint verification for remote servers. In most cases, you could get the remote server fingerprint using online services like [grc](https://www.grc.com/fingerprints.htm). However, in case of Google Docs, this will not work. Google serves HTTP client requests from different servers based on geographical location and time of day. Hence, any fingerprint obtained from say GRC, will be from GRC's client location. You won't get the right fingerprint since it needs to be fetched locally from your location, at this point in time. To get around this problem, you need to run *openssl* locally (on your computer) in Linux, to get the remote server's fingerprint. The command is as follows: (ref: [openssl s_client](http://askubuntu.com/questions/156620/how-to-verify-the-ssl-fingerprint-by-command-line-wget-curl/)) 96 | ```bash 97 | echo | openssl s_client -connect script.google.com:443 |& openssl x509 -fingerprint -noout 98 | ``` 99 | 100 | Windows users can either use it from within a Linux virtual machine or Cygwin. Another alternative is to use pre-compiled binaries of openssl for Windows. These are available at: [gnuwin32-openssl](http://gnuwin32.sourceforge.net/packages/openssl.htm) or [fulgan-openssl](https://indy.fulgan.com/SSL/). Open up *cmd* within Windows, goto the directory containing the binary and run the above command. I've uploaded a Windows batch file(fingerprint.bat) that you can use to automate getting the fingerprint in the future. 101 | 102 | (Note: For both Windows and Mac OS, remove replace the "|&" with just the pipe "|".) 103 | Command syntax explanation here: [grep-pipe-ampersand](http://askubuntu.com/questions/24953/using-grep-with-pipe-and-ampersand-to-filter-errors-from-find) 104 | 105 | This will fetch a fingerprint string. Put this string in the example main file *GoogleDocs.ino* (`const char* fingerprint`). 106 | You can call the method *setFingerprint()* as shown in the example to perform fingerprint verification. However, this is not mandatory. HTTPSRedirect will function correctly even in case of a certificate mismatch (Unless there is some real MiTM attack going on). Also remember that in case of Google's servers, this fingerprint will only be valid from your physical location for a few hours/days. In case you want to use fingerprint verification with Google Docs, you will have to keep generating a new fingerprint every few hours/days. 107 | 108 | Update Dec 2018: With the new version of esp8266 (v2.5.0-beta2) BearSSL is the default and currently I've not been able to verify fingerprints correctly, so it's been disabled. (setInsecure() is used before making requests). This will be updated in the future. 109 | 110 | --- 111 | 112 | # Sec. IV Working Example (Using Google Docs) 113 | ## Sec. IV(a) GoogleDocs.ino Arduino Script 114 | With Google Apps Script, you can publish your Google Scripts on the web. These scripts can access a variety of Google services, 115 | like Gmail, Google Docs, Calendar, Drive, etc. Google requires all access to their services use HTTP over SSL/TLS. Hence the regular *WiFiClient* is not suitable and *WiFiClientSecure* must be used. However, *WiFiClientSecure* does not follow redirects and hence doesn't work directly with Google Docs. 116 | 117 | When you publish your Google scripts, it'll be in the domain: **https://script.google.com/**. When you make a **GET** request to this 118 | URL, the data will be processed by your Google script, as long as you have a *doGet()* function in there. This is what a **GET** request to Google script will look like: 119 | 120 | ``` 121 | GET https://script.google.com/macros/s//exec 122 | ``` 123 | 124 | However, any data returned by *doGet()* is not passed on in the body of the response. This is what the initial response header 125 | looks like: 126 | ```http 127 | Access-Control-Allow-Origin: * 128 | Alt-Svc: quic=":443"; ma=2592000; v="32,31,30,29,28,27,26,25" 129 | Alternate-Protocol: 443:quic 130 | Cache-Control: no-cache, no-store, max-age=0, must-revalidate 131 | Content-Encoding: gzip 132 | Content-Type: text/html; charset=UTF-8 133 | Date: Mon, 25 Apr 2016 22:15:44 GMT 134 | Expires: Mon, 01 Jan 1990 00:00:00 GMT 135 | Location: https://script.googleusercontent.com/macros/echo? 136 | Pragma: no-cache 137 | Transfer-Encoding: chunked 138 | ``` 139 | 140 | The HTTP status code will be **302 Moved Temporarily**. 141 | 142 | Notice the field called **Location** in the response header. Even though we hit the script URL correctly (and passed on any parameters through the **GET** request), we will now need to follow this second link in order to get the return data. The second **GET** request has to be made to the domain: **https://script.googleusercontent.com/**. This URL is of the form: 143 | ```http 144 | https://script.googleusercontent.com 145 | /macros/echo? 146 | lib= 147 | user_content_key= 148 | ``` 149 | The value of *lib* will be the same for a given published script. *user_content_key* will change for every content served up by the doGet() or doPost() within apps script. 150 | 151 | *HTTPSRedirect* follows this URL in a seamless fashion. It'll make both the **GET** requests and return the final data from the server in the response body. 152 | 153 | Please check the **GoogleDocs** Arduino example included above, on how to use this library. The server-side code is in the file **GoogleScript.gs**, that you can use for your own spreadsheet. It also has an image of the test calendar whose entries are fetched by the above example. 154 | 155 | My copy of the spreadsheet can be found at: [spreadsheet](http://bit.ly/1Ql4qrN). 156 | 157 | You can view the contents of cell 'A1', the data rows and the chart here. Any new data from your device will be appended at the end. 158 | 159 | In order to view the return values from Google Docs, you need to open up a serial port terminal program (like CoolTerm) and connect to your IoT device (like ESP8266) from there. An easier option is to use the in-built "Serial Monitor" within Arduino itself. The advantage of this (over say Coolterm) is that it automatically disconnects when you recompile and re-flash, and then automatically reconnects to ESP8266. This saves a lot of effort in manually disconnecting and freeing up the serial port everytime we want to re-flash. 160 | 161 | The Arduino example does the following: 162 | 1. Makes a GET request to the script attached to the Google Spreadsheet, and write a value in the cell 'A1'. 163 | 164 | 2. Make a GET request and fetches entries for the next 1 week from my Google calendar's test calendar. 165 | 166 | 3. Make repeated GET requests to read the cell 'A1' of the spreadsheet. In this way, if you manually type something in the cell (within your own copy of the spreadsheet), you can *chat* with the ESP8266 :smile: 167 | 168 | 4. Makes repeated POST requests and records the current value of the free heap and free stack sizes into the sheet. These are plotted in the chart. 169 | 170 | Following is a representative image of the spreadsheet. (Yours may not look like this if the data has been cleared. To generate a chart similar to this, create your own spreadsheet as explained in the next section, and let the device record around 200 rows of data.) 171 |

172 | 173 | The test calendar that I have in my Google Calendar account looks like this: 174 |

175 | 176 | The data is fetched from my Spreadsheet and Google calendar. This is the Serial output: 177 |

178 | 179 | --- 180 | 181 | ## Sec. IV(b) Steps to get it working 182 | You need to be familiar with using Arduino IDE in general and how to use the IDE to create a project and flash the ESP8266. Refer this to link for guidance: [programming-esp8266-arduino](https://create.arduino.cc/projecthub/Metavix/programming-the-esp8266-with-the-arduino-ide-601c16) 183 | 184 | I tested the code on an ESP8266 model ESP-01 and ESP-01E. It should work on the other higher flash memeory versions as well (like ESP-12). 185 | 186 | ### Client side 187 | 1. Download the project files. Create a new project called 'GoogleDocs' within Arduino and load all the relevant files above. 188 | 2. Set the correct configuration parameters in the IDE: Board type: 'generic ESP8266', Flash size, Upload speed etc. based on your board. 189 | 3. In GoogleDocs.ino, set the following: (a) Your wifi SSID and password (b) Terminal UART speed in the line `Serial.begin(115200);`. 190 | 4. Compile and flash it onto the board. If all goes well and it is able to connect through your router to Google Docs, you should see the correct output in the terminal. Note: Some people have reported that it fails to connect randomly. This may be a problem with your router, DNS or firewall settings. In that case, please switch to another router/wireless access point. 191 | 5. As it stands, it will work *as-is with my copy* of the Spreadsheet and Google calendar. It will write to it and read from it. But you won't be able to modify it yourself. In order to create a copy of the sheet for yourself so that you can modify it, follow the steps for server side as described below. 192 | 193 | ### Server side 194 | You need to be familiar with the basics of Javascript (on which Google-script is based) as well as the basics of using Google Apps Script editor to publish your own scripts. Refer to the guide here: [apps-script-tutorial](https://developers.google.com/apps-script/articles). 195 | 196 | The spreadsheet (copyable) is here: [sample-spreadsheet](http://bit.ly/2og5Ldt). Create a copy of it in order to edit the contents. What you type in cell 'A1' will be reflected in the device Serial output. 197 | 198 | You could also create your own calendar entries. Just make sure they repeat per week and change the calendar name appropriately in the `function GetEventsOneWeek()` within GoogleScript.gs. 199 | 200 | The key steps for creating your own copy of the Spreadsheet and activating the script: 201 | 1. Create a new Google Spreadsheet in your account. 202 | 2. Goto Tools->Script editor... and copy all the code from *GoogleScript.gs* into the editor. 203 | 3. You can goto the menu item "ESP8266 Logging -> Clear" to clear all the row contents from the sheet. 204 | 4. Get your *spreadsheet-id*. If you look at the URL in the browser tab where the spreadsheet is open, it'll be of the form: 205 | `https://docs.google.com/spreadsheets/d//edit#gid=0`. The *\* is your *spreadsheet-id*. Put this value in *GoogleScript.gs* in the relevant line. 206 | 5. Publish your script by deploying it as a web app. The permissions should be set to "Execute the app as: Me (your email)" and "who has access to the app: Anyone, even anonymous". Once you publish your script, the script editor popup will say: "This project is now deployed as a web app.". It'll also display the URL for the webapp. Grab the string of random characters between "/macros/s/" and /"exec". 207 | 208 | Example: If your URL looks like this: `https://script.google.com/macros/s/XXXYYY/exec`, then "XXXYYY" is your **GScriptId**. Put this value in GoogleDocs.ino for it to hit your script instead of mine. 209 | 210 | **Important Note:** You need to re-publish your web-app (with a new version number) **every time** any change any made to your script. Google Apps script serves requests only with a published version of your script, not necessarily the *latest* one. This is an unfortunate Google Apps Script limitation. However, your *GScriptId* will remain the same. 211 | 212 | 6. Once these steps are completed, re-flash your ESP82666 with the new spreadsheet-id code. It should then read and write to your copy of the spreadsheet. 213 | 214 | --- 215 | Note: HTTPSRedirect is free for personal, non-commercial use only. In case of use for profit or more than 10 devices per person, please contact the author for purchasing a licence. 216 | 217 | I hope you enjoy using this library. Please try it out for yourself. Your comments and suggestions are most welcome. 218 | If you like my work and would like to buy me some :coffee: :beer:, you can send your contributions here: 219 |

220 | 221 | Users in India can donate using UPI to my wallet: electronicsguy@icici 222 | ![UPI_QR_code](https://github.com/electronicsguy/HTTPSRedirect/blob/main/Extra/upi.jpg) 223 | -------------------------------------------------------------------------------- /config.cpp: -------------------------------------------------------------------------------- 1 | // HTTPSRedirect Configuration file 2 | // Fill in your Wifi network credentials 3 | #ifndef HTTPSREDIRECT_CONFIG 4 | #define HTTPSREDIRECT_CONFIG 5 | const char* ssid = ""; 6 | const char* password = ""; 7 | 8 | const char* host = "script.google.com"; 9 | // Replace this with your own Google Sheets 10 | // script-id to make server side changes 11 | const char *GScriptId = "AKfycbzYw5G-oxvnwHpAJfDsS0PWNrO0KTBMiCW78lHUcEO6ZnFHvSw"; 12 | 13 | #endif -------------------------------------------------------------------------------- /keywords.txt: -------------------------------------------------------------------------------- 1 | ####################################### 2 | # Syntax Coloring Map For HTTPSRedirect 3 | ####################################### 4 | 5 | ####################################### 6 | # Datatypes (KEYWORD1) 7 | ####################################### 8 | 9 | HTTPSRedirect KEYWORD1 10 | 11 | ####################################### 12 | # Methods and Functions (KEYWORD2) 13 | ####################################### 14 | 15 | GET KEYWORD2 16 | POST KEYWORD2 17 | getStatusCode KEYWORD2 18 | getReasonPhrase KEYWORD2 19 | getResponseBody KEYWORD2 20 | setPrintResponseBody KEYWORD2 21 | setMaxRedirects KEYWORD2 22 | setContentTypeHeader KEYWORD2 23 | reConnectFinalEndpoint KEYWORD2 24 | 25 | 26 | ####################################### 27 | # Constants (LITERAL1) 28 | ####################################### 29 | -------------------------------------------------------------------------------- /library.json: -------------------------------------------------------------------------------- 1 | { 2 | "name": "HTTPSRedirect", 3 | "description": "HTTPS on ESP8266 with follow redirects, chunked encoding support", 4 | "keywords": "esp8266, http, redirects", 5 | "authors": 6 | { 7 | "name": "Sujay Phadke" 8 | }, 9 | "repository": 10 | { 11 | "type": "git", 12 | "url": "https://github.com/electronicsguy/HTTPSRedirect.git" 13 | }, 14 | "version": "2.1", 15 | "frameworks": [ 16 | "arduino", 17 | ], 18 | "platforms": "*" 19 | } 20 | -------------------------------------------------------------------------------- /library.properties: -------------------------------------------------------------------------------- 1 | name=HTTPSRedirect 2 | version=2.1 3 | author=electronicsguy 4 | maintainer=electronicsguy 5 | sentence=HTTPS with follow-redirects 6 | paragraph=HTTPS on ESP8266 with follow redirects, chunked encoding support 7 | category=Communication 8 | url=https://github.com/electronicsguy/HTTPSRedirect 9 | architectures=esp8266 10 | 11 | --------------------------------------------------------------------------------