There are some APIs from ESP8266 lib ESP missing like:

ESP.getSketchSize()
ESP.getFreeSketchSpace()
ESP.getSketchMD5()

Most interested in getSketchMD5. Working to implement these, but new to esp32 and need to understand the IDF more, so if anyone has hints, these are appreciate. Trying to understand how partitions work, since i think ill have to hash the current working partition, similar to how the esp8266 does it.