// the find
Azure/azure-iot-pal-esp32
Adaptation layer for the Azure IoT Hub SDK for ESP32
A PAL (platform abstraction layer) that once let the Azure IoT Hub C SDK run on ESP32. Microsoft retired it in 2018 and handed ownership to Espressif. The README's first line tells you to go elsewhere, yet the repo kept accumulating stars and forks for years after that.
- The TLS I/O layer (tlsio_openssl_compact.c) is a clean, minimal OpenSSL wrapper that avoids pulling in the full mbedTLS stack — worth reading if you're porting TLS to a constrained device
- Has actual unit tests for the TLS layer in sdk_tests/, which is rare for embedded PAL code of this vintage
- The socket_async abstraction is small enough to understand in an afternoon and port to other RTOS targets
- Officially dead since July 2018 — the README says so in the first line. Do not use this; go to the Espressif fork instead
- Last push was 2023 but the content hasn't meaningfully changed; the commits are probably dependency bumps or security file updates, not real maintenance
- The sdk submodule pins a specific Azure IoT C SDK version from ~2017-2018 era — you'd be on an ancient SDK with known CVEs if you somehow got this running
- Connection string is hardcoded in sample source (static const char* connectionString = "") with no mention of secure storage or NVS — bad practice that beginners will copy