DFU MCUmgr Base64 encoder/decoder

[thanosPr]

Hello,

I have successfully update my NRF52840 device over serial using mcumgr cli.

I am trying to implement mcumgr protocol into another microcontroller (esp32) in order to update nrf52840 over WiFi.

My problem is that i am not able to reproduce the same result using base64 enconding/decoding.

I attach a debug overview between nrf52480 and mcumgr cli. I am aware of smp protocol (smp header + payload)

Reset Command:

Tx Request: 02 00 00 01 00 00 8a 05  a0 

Tx Base64 Encoding:

Start Initial Frame: 06 09

Body: 41 41 73 43 41 41 41 42  41 41 43 4b 42 61 41 31  51 77 3d 3d

End Frame: 0a

I have used base64 online encoder/decoder and also implement my own to validate with no luck regarding the mcumgr output result.

One of base64 calculators: https://base64.guru/converter/decode/hex

Hex: 02 00 00 01 00 00 8a 05

MyBase64: AgAAAQAAigU=   MCUmgrBase64: AAsCAAABAACKBaA1

Could you please help me how this "body packet" is produced?

[thanosPr]

The issue comes from "missing" bytes in body frame. Packet length (two bytes) and CRC16 (two bytes) does not exist in log data.

Let me be more specific regarding the above debug overview:

Tx Request:

Start Frame: 06 09

Body: (00 0b) 02 00 00 01 00 00 8a 05  a0 (35 43)

00 0b = 11 bytes length

35 43 = CRC16

End Frame: 0A

Base64 Request:  AAsCAAABAACKBaA1Qw==

Problem solved.