STM32: ethernet w5500 with plain (HTTP) and SSL (HTTPS)
OPEnS is with a quiet amount of resources, allows standard Arduino Ethernet to use secure connections.
Software Apps and online services
STM32F1
STM32F4
| STM32 | w5500 |
|---|---|
| PA4 | CS |
| PA5 | SCK |
| PA6 | MISO |
| PA7 | MOSI |
| 3.3v (better with external 200mha) | VCC |
| GND | GND |
Retrieve certificate
To use an SSL, we need the server certificate, but in this case, SSLClient uses a trick given by BearSSL implementation. This minimal x509 verification engine allows using of Trust Anchors.
I add a simple online generator that you can find here.
You must only write the site’s address (httpbin.org) in the first input box, click Generate code, copy the code, and put it inside a file called trust_anchors.h and put it inside the sketch folder.






