Can you use BLK3 to store an arbitrary unique id?
Posted: Fri Nov 24, 2017 8:39 pm
I had posted a while ago about a unique id on the ESP32 for use in authenticating commands.
Using espefuse.py I burnt a key to BLK3 like:
$IDF_PATH/components/esptool_py/esptool/espefuse.py --port /dev/ttyUSB0 burn_key BLK3 blk3_key.bin
Note that I used 'burn_key' because it seemed like the best approach but now the key isn't readable, even by the micro:
BLK1 Flash encryption key
= 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 R/W
BLK2 Secure boot key
= 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 R/W
BLK3 Variable Block 3
= 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 -/-
Should I have used 'burn_efuse' instead to avoid READ and WRITE from being cleared?
I'm asking because I only have so many esp-wroom-32 modules here and I'd prefer not to lock myself out of a second one
Using espefuse.py I burnt a key to BLK3 like:
$IDF_PATH/components/esptool_py/esptool/espefuse.py --port /dev/ttyUSB0 burn_key BLK3 blk3_key.bin
Note that I used 'burn_key' because it seemed like the best approach but now the key isn't readable, even by the micro:
BLK1 Flash encryption key
= 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 R/W
BLK2 Secure boot key
= 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 R/W
BLK3 Variable Block 3
= 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 -/-
Should I have used 'burn_efuse' instead to avoid READ and WRITE from being cleared?
I'm asking because I only have so many esp-wroom-32 modules here and I'd prefer not to lock myself out of a second one