Introduce Espressif common CONFIG_WOLFSSL_EXAMPLE_NAME, Kconfig

[gojimmypi]

Description

This PR introduces common KConfig and user setting files for the Espressif template app as it is the most basic example and least intrusive to change.

The intent is that all wolfSSL examples in all repos will have common user_settings.h , CMakeLists.txt and KConfig files, with only the sdkconfig.defaults varying. Rather than propose all changes to all examples at once, this PR for only the template example is for simplified code review.

Note that new configuration settings specific to ESP-IDF versions integrating wolfSSL are also included here. There's likely little to no effect on ESP-IDF versions that do not support the new features. As of the date of this PR, many features are only available on my ESP-IDF v5.2.2 fork.

The objective is to not only simplify the configuration of the user_settings.h file by utilizing the menuconfig capabilities, but in doing so will also prevent changes from being needed when using the wolfSSL Managed Component. Recall that making changes, such as to the user_settings.h file, causes the component manager to complain about changes. This forces the user to convert the Managed Component to a regular component, defeating the purpose and value of having a managed component in the first place.

Here's the new idf.py menuconfig as viewed in VisualGDB. Note the dropdown also increases end-user awareness to the other examples available:

Fixes zd#: Not "fixing" but related to 18228.

Testing

How did you test?

Tested only on Espressif targets.

Checklist

• added tests
• updated/added doxygen
• updated appropriate READMEs
• Updated manual and documentation

[douzzer]

Impressive work!

Little stuff: I Found 3 whitespace infractions, and left several question-comments. In particular, I think you left on some debug gates in the user_config.h inadvertently.

[douzzer]

fix hard tabs in the indentation here.

[gojimmypi]

ah yes, interesting. Visual Studio usually converts to spaces at save time. Good catch. Fixed

[douzzer]

more hard tabs to fix.

[gojimmypi]

also fixed

[douzzer]

suggest you either snip out the added space after #undef, or snip out a space afterwards to get the */ to line up.

[gojimmypi]

definitely!

[douzzer]

Is RSA default-disabled just as a space-saving measure, due to the small target?

[gojimmypi]

yes, good question. Having the default for "works on more systems" is desirable, particularly something like the C2 or Arduino Nano with limited memory.

The sdkconfig.defaults can be used to set defaults, as well as sdkconfig.defaults.[target] (see example).

I've been reluctant to include all the sdkconfig.defaults.[target] files in all the examples without a compelling reason, but in the future it might be better to enable RSA by default, and then include a sdkconfig.defaults.esp32c2 file that disables it.

[douzzer]

Does it make sense to enable debug gates in the example config? Maybe so. Just wondering if you considered the overhead.

Edit: There's actually another #define WOLFSSL_ESP32_HW_LOCK_DEBUG below, commented out.

[gojimmypi]

Does it make sense to enable debug gates in the example config? Maybe so.

Maybe, but not much interesting in this template example. I'll review with the other examples & see if any make sense without being too verbose. There's already some informative "always on" messages. See the ESP_LOGI() in the TLS Client Example. I'll definitely be adding more settings to control these from Kconfig / menuconfig.

Another #define WOLFSSL_ESP32_HW_LOCK_DEBUG below, commented out.

Good catch. I've removed the extra one.

[gojimmypi]

Thanks, @douzzer for the code review and attention to detail. I believe I've tidied things up.

[douzzer]

retest this please