:link_to_translation:`zh_CN:[中文]`
For ESP-IDF v5.0, Mbed TLS has been updated from v2.x to v3.1.0.
For more details about Mbed TLS's migration from version 2.x to version 3.0 or greater, please refer to the official guide.
- Direct access to fields of structures (
structtypes) declared in public headers is no longer supported. - Appropriate accessor functions (getter/setter) must be used for the same. A temporary workaround would be to use
MBEDTLS_PRIVATEmacro (not recommended). - For more details, refer to the official guide.
- Removed support for TLS 1.0, 1.1, and DTLS 1.0
- Removed support for SSL 3.0
- The functions
mbedtls_*_ret()(related to MD, SHA, RIPEMD, RNG, HMAC modules) was renamed to replace the corresponding functions without_retappended and updated return value. - For more details, refer to the official guide.
Following are some of the important config options deprecated by this update. The configs related to and/or dependent on these have also been deprecated.
MBEDTLS_SSL_PROTO_SSL3: Support for SSL 3.0MBEDTLS_SSL_PROTO_TLS1: Support for TLS 1.0MBEDTLS_SSL_PROTO_TLS1_1: Support for TLS 1.1MBEDTLS_SSL_PROTO_DTLS: Support for DTLS 1.1 (Only DTLS 1.2 is supported now)MBEDTLS_DES_C: Support for 3DES ciphersuitesMBEDTLS_RC4_MODE: Support for RC4-based ciphersuites
Note
This list includes only major options configurable through idf.py menuconfig. For more details on deprecated options, refer to the official guide.
The Diffie-Hellman Key Exchange modes have now been disabled by default due to security risks (see warning text here). Related configs are given below:
MBEDTLS_DHM_C: Support for the Diffie-Hellman-Merkle moduleMBEDTLS_KEY_EXCHANGE_DHE_PSK: Support for Diffie-Hellman PSK (pre-shared-key) TLS authentication modesMBEDTLS_KEY_EXCHANGE_DHE_RSA: Support for cipher suites with the prefixTLS-DHE-RSA-WITH-
Note
During the initial step of the handshake (i.e. client_hello), the server selects a cipher from the list that the client publishes. As the DHE_PSK/DHE_RSA ciphers have now been disabled by the above change, the server would fall back to an alternative cipher; if in a rare case, it does not support any other cipher, the handshake would fail. To retrieve the list of ciphers supported by the server, one must attempt to connect with the server with a specific cipher from the client-side. Few utilities can help do this, e.g. sslscan.
- The
mbedtls/certs.hheader is no longer available in mbedtls 3.1. Most applications can safely remove it from the list of includes.
- The :cpp:func:`esp_crt_bundle_set()` API now requires one additional argument named
bundle_size. The return type of the API has also been changed to :cpp:type:`esp_err_t` fromvoid.
- The :cpp:func:`esp_ds_rsa_sign()` API now requires one less argument. The argument
modeis no longer required.
Names of variables holding different certs in :cpp:type:`httpd_ssl_config_t` structure have been updated.
.. list::
* :cpp:member:`httpd_ssl_config::servercert` variable inherits role of ``cacert_pem`` variable.
* :cpp:member:`httpd_ssl_config::servercert_len` variable inherits role of ``cacert_len`` variable
* :cpp:member:`httpd_ssl_config::cacert_pem` variable inherits role of ``client_verify_cert_pem`` variable
* :cpp:member:`httpd_ssl_config::cacert_len` variable inherits role of ``client_verify_cert_len`` variable
The return type of the :cpp:func:`httpd_ssl_stop` API has been changed to :cpp:type:`esp_err_t` from void.
- The function :cpp:func:`esp_https_ota` now requires pointer to :cpp:type:`esp_https_ota_config_t` as argument instead of pointer to :cpp:type:`esp_http_client_config_t`.
The :cpp:type:`esp_tls_t` has now been made completely private. You cannot access its internal structures directly. Any necessary data that needs to be obtained from the ESP-TLS handle can be done through respective getter/setter functions. If there is a requirement of a specific getter/setter function, please raise an issue on ESP-IDF.
The list of newly added getter/setter function is as as follows:
.. list::
* :cpp:func:`esp_tls_get_ssl_context` - Obtain the ssl context of the underlying ssl stack from the ESP-TLS handle.
Following table summarizes the deprecated functions removed and their alternatives to be used from ESP-IDF v5.0 onwards.
| Deprecated Function | Alternative |
|---|---|
esp_tls_conn_new() |
:cpp:func:`esp_tls_conn_new_sync` |
esp_tls_conn_delete() |
:cpp:func:`esp_tls_conn_destroy` |
- The function :cpp:func:`esp_tls_conn_http_new` has now been termed as deprecated. Please use the alternative function :cpp:func:`esp_tls_conn_http_new_sync` (or its asynchronous :cpp:func:`esp_tls_conn_http_new_async`). Note that the alternatives need an additional parameter :cpp:type:`esp_tls_t`, which has to be initialized using the :cpp:func:`esp_tls_init` function.
http_server.hheader is no longer available inesp_http_server. Please useesp_http_server.hinstead.
- The functions :cpp:func:`esp_http_client_read` and :cpp:func:`esp_http_client_fetch_headers` now return an additional return value
-ESP_ERR_HTTP_EAGAINfor timeout errors - call timed-out before any data was ready.
- The function :cpp:func:`esp_transport_read` now returns
0for a connection timeout and< 0for other errors. Please refer :cpp:enum:`esp_tcp_transport_err_t` for all possible return values.
- :cpp:type:`esp_mqtt_client_config_t` have all fields grouped in sub structs.
Most common configurations are listed below:
- Broker address now is set in :cpp:member:`esp_mqtt_client_config_t::broker::address::uri`
- Security related to broker verification in :cpp:member:`esp_mqtt_client_config_t::broker::verification`
- Client username is set in :cpp:member:`esp_mqtt_client_config_t::credentials::username`
- :cpp:type:`esp_mqtt_client_config_t` no longer supports the
user_contextfield. Please use :cpp:func:`esp_mqtt_client_register_event` instead for registering an event handler; the last argumentevent_handler_argcan be used to pass user context to the handler.
The ESP-IDF component freemodbus has been removed from ESP-IDF and is supported as a separate component. Additional information for the ESP-Modbus component can be found in the separate repository:
The main component folder of the new application shall include the component manager manifest file idf_component.yml as in the example below:
dependencies:
espressif/esp-modbus:
version: "^1.0"
The esp-modbus component can be found in component manager registry. Refer to component manager documentation for more information on how to set up the component manager.
For applications targeting v4.x releases of ESP-IDF that need to use new esp-modbus component, adding the component manager manifest file idf_component.yml will be sufficient to pull in the new component. However, users should also exclude the legacy freemodbus component from the build. This can be achieved using the statement below in the project's CMakeLists.txt:
set(EXCLUDE_COMPONENTS freemodbus)