This component is built on top of esp_http_server. The HTTPS server takes advantage of hooks and function overrides in the regular HTTP server to provide encryption using OpenSSL.
All documentation for esp_http_server applies also to a server you create this way.
The following API of esp_http_server should not be used with esp_https_server, as they are used internally to handle secure sessions and to maintain internal state:
- "send", "receive" and "pending" function overrides - secure socket handling
- :cpp
httpd_sess_set_send_override - :cpp
httpd_sess_set_recv_override - :cpp
httpd_sess_set_pending_override
- :cpp
- "transport context" - both global and session
- :cpp
httpd_sess_get_transport_ctx- returns SSL used for the session - :cpp
httpd_sess_set_transport_ctx - :cpp
httpd_get_global_transport_ctx- returns the shared SSL context - :c
httpd_config_t.global_transport_ctx - :c
httpd_config_t.global_transport_ctx_free_fn - :c
httpd_config_t.open_fn- used to set up secure sockets
- :cpp
Everything else can be used without limitations.
Please see the example protocols/https_server to learn how to set up a secure server.
Basically all you need is to generate a certificate, embed it in the firmware, and provide its pointers and lengths to the start function via the init struct.
The server can be started with or without SSL by changing a flag in the init struct - :chttpd_ssl_config.transport_mode. This could be used e.g. for testing or in trusted environments where you prefer speed over security.
The initial session setup can take about two seconds, or more with slower clock speeds or more verbose logging. Subsequent requests through the open secure socket are much faster (down to under 100 ms).