mirror of
https://github.com/espressif/esp-idf.git
synced 2024-10-05 20:47:46 -04:00
95 lines
4.5 KiB
ReStructuredText
95 lines
4.5 KiB
ReStructuredText
ESP-TLS
|
|
=======
|
|
|
|
Overview
|
|
--------
|
|
|
|
The ESP-TLS component provides a simplified API interface for accessing the commonly used TLS functionality.
|
|
It supports common scenarios like CA certification validation, SNI, ALPN negotiation, non-blocking connection among others.
|
|
All the configuration can be specified in the ``esp_tls_cfg_t`` data structure. Once done, TLS communication can be conducted using the following APIs:
|
|
|
|
* :cpp:func:`esp_tls_conn_new`: for opening a new TLS connection.
|
|
* :cpp:func:`esp_tls_conn_read`: for reading from the connection.
|
|
* :cpp:func:`esp_tls_conn_write`: for writing into the connection.
|
|
* :cpp:func:`esp_tls_conn_delete`: for freeing up the connection.
|
|
|
|
Any application layer protocol like HTTP1, HTTP2 etc can be executed on top of this layer.
|
|
|
|
Application Example
|
|
-------------------
|
|
|
|
Simple HTTPS example that uses ESP-TLS to establish a secure socket connection: :example:`protocols/https_request`.
|
|
|
|
Tree structure for ESP-TLS component
|
|
-------------------------------------
|
|
.. highlight:: none
|
|
|
|
::
|
|
|
|
├── esp_tls.c
|
|
├── esp_tls.h
|
|
├── esp_tls_mbedtls.c
|
|
├── esp_tls_wolfssl.c
|
|
└── private_include
|
|
├── esp_tls_mbedtls.h
|
|
└── esp_tls_wolfssl.h
|
|
|
|
The ESP-TLS component has a file :component_file:`esp-tls/esp_tls.h` which contain the public API headers for the component. Internally ESP-TLS component uses one
|
|
of the two SSL/TLS Libraries between mbedtls and wolfssl for its operation. API specific to mbedtls are present in :component_file:`esp-tls/private_include/esp_tls_mbedtls.h` and API
|
|
specific to wolfssl are present in :component_file:`esp-tls/private_include/esp_tls_wolfssl.h`.
|
|
|
|
Underlying SSL/TLS Library Options
|
|
----------------------------------
|
|
The ESP-TLS component has an option to use mbedtls or wolfssl as their underlying SSL/TLS library. By default only mbedtls is available and is
|
|
used, wolfssl SSL/TLS library is available publicly at https://github.com/espressif/esp-wolfssl. The repository provides wolfssl component in binary format, it
|
|
also provides few examples which are useful for understanding the API. Please refer the repository README.md for
|
|
information on licensing and other options. Please see below option for using wolfssl in your project.
|
|
|
|
.. note:: `As the library options are internal to ESP-TLS, switching the libries will not change ESP-TLS specific code for a project.`
|
|
|
|
How to use wolfssl with ESP-IDF
|
|
-------------------------------
|
|
There are two ways to use wolfssl in your project
|
|
|
|
1) Directly add wolfssl as a component in your project with following three commands.::
|
|
|
|
(First change directory (cd) to your project directory)
|
|
mkdir components
|
|
cd components
|
|
git clone https://github.com/espressif/esp-wolfssl.git
|
|
|
|
2) Add wolfssl as an extra component in your project.
|
|
|
|
* Download wolfssl with::
|
|
|
|
git clone https://github.com/espressif/esp-wolfssl.git
|
|
|
|
* Include esp-wolfssl in ESP-IDF with setting EXTRA_COMPONENT_DIRS in CMakeLists.txt/Makefile of your project as done in `wolfssl/examples <https://github.com/espressif/esp-wolfssl/tree/master/examples>`_. For reference see Optional Project variables in :doc:`build-system.</api-guides/build-system>`
|
|
|
|
After above steps, you will have option to choose wolfssl as underlying SSL/TLS library in configuration menu of your project as follows::
|
|
|
|
idf.py/make menuconfig -> ESP-TLS -> choose SSL/TLS Library -> mbedtls/wolfssl
|
|
|
|
Comparison between mbedtls and wolfssl
|
|
--------------------------------------
|
|
The following table shows a typical comparison between wolfssl and mbedtls when :example:`protocols/https_request` example `(which has server authentication)` was run with both
|
|
SSL/TLS libraries and with all respective configurations set to default.
|
|
`(mbedtls IN_CONTENT length and OUT_CONTENT length were set to 16384 bytes and 4096 bytes respectively)`
|
|
|
|
+---------------------+------------+-----------+
|
|
| Property | Wolfssl | Mbedtls |
|
|
+=====================+============+===========+
|
|
| Total Heap Consumed | ~19 Kb | ~37 Kb |
|
|
+---------------------+------------+-----------+
|
|
| Task Stack Used | ~2.2 Kb | ~3.6 Kb |
|
|
+---------------------+------------+-----------+
|
|
| Bin size | ~858 Kb | ~736 Kb |
|
|
+---------------------+------------+-----------+
|
|
|
|
.. note:: `These values are subject to change with change in configuration options and version of respective libraries`.
|
|
|
|
API Reference
|
|
-------------
|
|
|
|
.. include-build-file:: inc/esp_tls.inc
|