BearSSL (https://www.bearssl.org) is a TLS(SSL) library written by Thomas Pornin that is optimized for lower-memory embedded systems like the ESP8266. It supports a wide variety of modern ciphers and is unique in that it doesn't perform any memory allocations during operation (which is the unfortunate bane of the current axTLS). BearSSL is also absolutely focused on security and by default performs all its security checks on x.509 certificates during the connection phase (but if you want to be insecure and dangerous, that's possible too). While it does support unidirectional SSL buffers, like axTLS, as implemented the ESP8266 wrappers only support bidirectional buffers. These bidirectional buffers avoid deadlocks in protocols which don't have well separated receive and transmit periods. This patch adds several classes which allow connecting to TLS servers using this library in almost the same way as axTLS: BearSSL::WiFiClientSecure - WiFiClient that supports TLS BearSSL::WiFiServerSecure - WiFiServer supporting TLS and client certs It also introduces objects for PEM/DER encoded keys and certificates: BearSSLX509List - x.509 Certificate (list) for general use BearSSLPrivateKey - RSA or EC private key BearSSLPublicKey - RSA or EC public key (i.e. from a public website) Finally, it adds a Certificate Authority store object which lets BearSSL access a set of trusted CA certificates on SPIFFS to allow it to verify the identity of any remote site on the Internet, without requiring RAM except for the single matching certificate. CertStoreSPIFFSBearSSL - Certificate store utility Client certificates are supported for the BearSSL::WiFiClientSecure, and what's more the BearSSL::WiFiServerSecure can also *require* remote clients to have a trusted certificate signed by a specific CA (or yourself with self-signing CAs). Maximum Fragment Length Negotiation probing and usage are supported, but be aware that most sites on the Internet don't support it yet. When available, you can reduce the memory footprint of the SSL client or server dramatically (i.e. down to 2-8KB vs. the ~22KB required for a full 16K receive fragment and 512b send fragment). You can also manually set a smaller fragment size and guarantee at your protocol level all data will fit within it. Examples are included to show the usage of these new features. axTLS has been moved to its own namespace, "axtls". A default "using" clause allows existing apps to run using axTLS without any changes. The BearSSL::WiFi{client,server}Secure implements the axTLS client/server API which lets many end user applications take advantage of BearSSL with few or no changes. The BearSSL static library used presently is stored at https://github.com/earlephilhower/bearssl-esp8266 and can be built using the standard ESP8266 toolchain.
Arduino core for ESP8266 WiFi chip
This project brings support for ESP8266 chip to the Arduino environment. It lets you write sketches using familiar Arduino functions and libraries, and run them directly on ESP8266, no external microcontroller required.
ESP8266 Arduino core comes with libraries to communicate over WiFi using TCP and UDP, set up HTTP, mDNS, SSDP, and DNS servers, do OTA updates, use a file system in flash memory, work with SD cards, servos, SPI and I2C peripherals.
Contents
- Installing options:
- Documentation
- Issues and support
- Contributing
- License and credits
Installing with Boards Manager
Starting with 1.6.4, Arduino allows installation of third-party platform packages using Boards Manager. We have packages available for Windows, Mac OS, and Linux (32 and 64 bit).
- Install the current upstream Arduino IDE at the 1.8 level or later. The current version is at the Arduino website.
- Start Arduino and open Preferences window.
- Enter
http://arduino.esp8266.com/stable/package_esp8266com_index.json
into Additional Board Manager URLs field. You can add multiple URLs, separating them with commas. - Open Boards Manager from Tools > Board menu and install esp8266 platform (and don't forget to select your ESP8266 board from Tools > Board menu after installation).
Latest release 
Boards manager link: http://arduino.esp8266.com/stable/package_esp8266com_index.json
Documentation: https://arduino-esp8266.readthedocs.io/en/2.4.1/
Using git version
- Install Arduino 1.8.2 from the Arduino website.
- Go to Arduino directory
- Clone this repository into hardware/esp8266com/esp8266 directory (or clone it elsewhere and create a symlink)
cd hardware
mkdir esp8266com
cd esp8266com
git clone https://github.com/esp8266/Arduino.git esp8266
- Download binary tools (you need Python 2.7)
cd esp8266/tools
python get.py
- Restart Arduino
Using PlatformIO
PlatformIO is an open source ecosystem for IoT development with cross platform build system, library manager and full support for Espressif (ESP8266) development. It works on the popular host OS: macOS, Windows, Linux 32/64, Linux ARM (like Raspberry Pi, BeagleBone, CubieBoard).
- What is PlatformIO?
- PlatformIO IDE
- PlatformIO Core (command line tool)
- Advanced usage - custom settings, uploading to SPIFFS, Over-the-Air (OTA), staging version
- Integration with Cloud and Standalone IDEs - Cloud9, Codeanywhere, Eclipse Che (Codenvy), Atom, CLion, Eclipse, Emacs, NetBeans, Qt Creator, Sublime Text, VIM, Visual Studio, and VSCode
- Project Examples
Building with make
makeEspArduino is a generic makefile for any ESP8266 Arduino project. Using make instead of the Arduino IDE makes it easier to do automated and production builds.
Documentation
Documentation for latest development version: https://arduino-esp8266.readthedocs.io/en/latest/
Issues and support
ESP8266 Community Forum is a well established community for questions and answers about Arduino for ESP8266.
If you find this forum useful, please consider supporting it with a donation.
If you encounter an issue which you think is a bug in the ESP8266 Arduino Core or the associated libraries, you are welcome to submit it here on Github: https://github.com/esp8266/Arduino/issues.
Please provide as much context as possible:
- ESP8266 Arduino core version which you are using (you can check it in Boards Manager)
- your sketch code; please wrap it into a code block, see Github markdown manual
- when encountering an issue which happens at run time, attach serial output. Wrap it into a code block, just like the code.
- for issues which happen at compile time, enable verbose compiler output in the IDE preferences, and attach that output (also inside a code block)
- ESP8266 development board model
- IDE settings (board choich, flash size)
Contributing
For minor fixes of code and documentation, please go ahead and submit a pull request.
Check out the list of issues which are easy to fix — easy issues for 2.5.0. Working on them is a great way to move the project forward.
Larger changes (rewriting parts of existing code from scratch, adding new functions to the core, adding new libraries) should generally be discussed by opening an issue first.
Feature branches with lots of small commits (especially titled "oops", "fix typo", "forgot to add file", etc.) should be squashed before opening a pull request. At the same time, please refrain from putting multiple unrelated changes into a single pull request.
License and credits
Arduino IDE is developed and maintained by the Arduino team. The IDE is licensed under GPL.
ESP8266 core includes an xtensa gcc toolchain, which is also under GPL.
Esptool written by Christian Klippel is licensed under GPLv2, currently maintained by Ivan Grokhotkov: https://github.com/igrr/esptool-ck.
Espressif SDK included in this build is under Espressif MIT License.
ESP8266 core files are licensed under LGPL.
SPI Flash File System (SPIFFS) written by Peter Andersson is used in this project. It is distributed under MIT license.
umm_malloc memory management library written by Ralph Hempel is used in this project. It is distributed under MIT license.
axTLS library written by Cameron Rich, built from https://github.com/igrr/axtls-8266, is used in this project. It is distributed under BSD license.