burn_key operation gives Burn BLOCK_KEY0 (['BLOCK4']) was not successful (ESPTOOL-986)

[Daphne-HU]

Operating System

Xubuntu 20.04 (under WSL)

Esptool Version

4.7.0

Python Version

3.8.10

Chip Description

esp32-C3-mini-1

Device Description

Chip is on a custom PCB

Hardware Configuration

When relevant i can provide pin configurations

How is Esptool Run

Visual studio code

Full Esptool Command Line that Was Run

espefuse.py --debug burn_key BLOCK_KEY0 flash_encryption_key.bin XTS_AES_128_KEY

Esptool Output

vscode@4d6257b198cd:/workspaces/BCE-Monitor$ espefuse.py --debug burn_key BLOCK_KEY0 flash_encryption_key.bin XTS_AES_128_KEY
espefuse.py v4.7.0
Connecting...
Detecting chip type... ESP32-C3
BLOCK0          (                ) [0 ] read_regs: 00000000 00000000 00000000 00000000 80000000 00000000
MAC_SPI_8M_0    (BLOCK1          ) [1 ] read_regs: <data>
BLOCK_SYS_DATA  (BLOCK2          ) [2 ] read_regs: <data>
BLOCK_USR_DATA  (BLOCK3          ) [3 ] read_regs: 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000
BLOCK_KEY0      (BLOCK4          ) [4 ] read_regs: 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000
BLOCK_KEY1      (BLOCK5          ) [5 ] read_regs: 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000
BLOCK_KEY2      (BLOCK6          ) [6 ] read_regs: 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000
BLOCK_KEY3      (BLOCK7          ) [7 ] read_regs: 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000
BLOCK_KEY4      (BLOCK8          ) [8 ] read_regs: 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000
BLOCK_KEY5      (BLOCK9          ) [9 ] read_regs: 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000
BLOCK_SYS_DATA2 (BLOCK10         ) [10] read_regs: 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000

BLOCK0          (                ) [0 ] err__regs: 00000000 00000000 00000000 00000000 00000000 00000000
EFUSE_RD_RS_ERR0_REG        0x00000000
EFUSE_RD_RS_ERR1_REG        0x00000000

=== Run "burn_key" command ===
Burn keys to blocks:
 - BLOCK_KEY0 -> [<my key>]
        Reversing byte order for AES-XTS hardware peripheral
        'KEY_PURPOSE_0': 'USER' -> 'XTS_AES_128_KEY'.
        Disabling write to 'KEY_PURPOSE_0'.
        Disabling read to key block
        Disabling write to key block


Check all blocks for burn...
idx, BLOCK_NAME,          Conclusion
[00] BLOCK0               is not empty
        (written ): 0x000000008000000000000000000000000000000000000000
        (to write): 0x<key>
        (coding scheme = NONE)
[01] MAC_SPI_8M_0         nothing to burn
[02] BLOCK_SYS_DATA       nothing to burn
[03] BLOCK_USR_DATA       nothing to burn
[04] BLOCK_KEY0           is empty, will burn the new value
[05] BLOCK_KEY1           nothing to burn
[06] BLOCK_KEY2           nothing to burn
[07] BLOCK_KEY3           nothing to burn
[08] BLOCK_KEY4           nothing to burn
[09] BLOCK_KEY5           nothing to burn
[10] BLOCK_SYS_DATA2      nothing to burn
. 
This is an irreversible operation!
Type 'BURN' (all capitals) to continue.
BURN
BLOCK_KEY0      (BLOCK4          ) [4 ] to_write: <my key>
Write data to BLOCK4
Addr 0x60008800, data=0x..
Addr 0x60008804, data=0x..
Addr 0x60008808, data=0x..
Addr 0x6000880c, data=0x..
Addr 0x60008810, data=0x..
Addr 0x60008814, data=0x..
Addr 0x60008818, data=0x..
Addr 0x6000881c, data=0x..
Addr 0x60008820, data=0x..
Addr 0x60008824, data=0x..
Addr 0x60008828, data=0x..
BLOCK_KEY0      (BLOCK4          ) [4 ] read_regs: 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000
BLOCK_KEY0      (BLOCK4          ) [4 ] Expected: <my key>
BLOCK_KEY0      (BLOCK4          ) [4 ] Real    : 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000

A fatal error occurred: Burn BLOCK_KEY0 (['BLOCK4']) was not successful

More Information

I followed the documentation as noted here, under Using Host Generated Key:
https://docs.espressif.com/projects/esp-idf/en/release-v5.1/esp32c3/security/flash-encryption.html

When I run "espefuse.py summary," it displays what appears to be the basic fabric configuration settings.
Nothing is changed before trying to burn the flash key.

Other Steps to Reproduce

I Have Read the Troubleshooting Guide

• I confirm I have read the troubleshooting guide.

[KonstantinKondrashov]

Hi @Daphne-HU!
The command is correct. If nothing is changed then the problem is likely hardware-related. You can try programming it into a different BLOCK_KEY.
Possible hardware-related issues:

• ESD (Electrostatic Discharge): Ensure proper handling and grounding to prevent damage.
• Weak Power Supply: Verify the power supply's stability and ensure it meets the ESP32-C3's voltage and current requirements.

[Daphne-HU]

I have attempted the suggested solutions, including using different power supplies and PCBs, but the issue persists. I also tried programming a different BLOCK_KEY without success. Could there be other potential causes or solutions to this problem?

on a new device i tried writing with no read and write protect:

vscode@4d6257b198cd:/workspaces/BCE-Monitor$ espefuse.py burn_key --no-write-protect --no-read-protect BLOCK_KEY4 flash_encryption_key.bin XTS_AES_128_KEY
espefuse.py v4.7.0
Connecting...
Detecting chip type... ESP32-C3

=== Run "burn_key" command ===
Sensitive data will be hidden (see --show-sensitive-info)
Burn keys to blocks:

• BLOCK_KEY4 -> [?? ?? ?? ?? ?? ?? ?? ?? ?? ?? ?? ?? ?? ?? ?? ?? ?? ?? ?? ?? ?? ?? ?? ?? ?? ?? ?? ?? ?? ?? ?? ??]
  Reversing byte order for AES-XTS hardware peripheral
  'KEY_PURPOSE_4': 'USER' -> 'XTS_AES_128_KEY'.
  Disabling write to 'KEY_PURPOSE_4'.

Keys will remain writeable (due to --no-write-protect)
Keys will remain readable (due to --no-read-protect)

Check all blocks for burn...
idx, BLOCK_NAME, Conclusion
[00] BLOCK0 is not empty
(written ): 0x000000008000000000000000000000000000000000000000
(to write): 0x000000000000000000000400000000000000000000001000
(coding scheme = NONE)
[08] BLOCK_KEY4 is empty, will burn the new value
.
This is an irreversible operation!
Type 'BURN' (all capitals) to continue.
BURN
Error in BLOCK8, re-burn it again (#0), to fix it. fail_bit=1, num_errors=0
Error in BLOCK8, re-burn it again (#1), to fix it. fail_bit=1, num_errors=0
Error in BLOCK8, re-burn it again (#2), to fix it. fail_bit=1, num_errors=0

A fatal error occurred: Burn BLOCK_KEY4 (['BLOCK8']) was not successful

A bit more than half of the key is written correctly in BOCK8 / BLOCK_KEY4
under in the summary:
Error(s) in BLOCK8 [ERRORS:0 FAIL:1]

BLOCK0 ( ) [0 ] err__regs: 00000000 00000000 00000000 00000000 00000000 00000000
EFUSE_RD_RS_ERR0_REG 0x00000000
EFUSE_RD_RS_ERR1_REG 0x00000008