Lora payload decryption

I have got the below values and I want to know how I can decrypt the bytes part.

bytes:“tgrJ5g4JoNCLmCmzRg==”
hex=“B60AC9E60E09A0D08B9829B346”
nwkkey=“67f39a7b60b807f833a497875467a3c2”
appkey=“c40af93e37530e3c87bb79486e6d8966”

Thank You,

Akarsh.

I would start here and look at the decrypt methods (if you’re familiar with Go):

When I try to decrypt the payload using aes-counter-128 and appSessionKey I dont get the actual plaintext.
Why might be this a problem?

I have found the payload by removing the mac header and MIC.

1 Like

The Link : LoRaWAN 1.0.x packet decoder

I tried and just get a little bit your data . I think your data is reversed by MSB or LSB

The tool is for parsing the received lora packet.
I seperated the MIC and header part from the received packet. I am trying to decrypt the payload part using aes-counter-decrypt, where i am getting gibberish.

I developed a sniffer code in arduino for lora packets. The radiohead library truncates first 4 header bytes, so I was not able to decode it properly. I changed the library code and now its working fine.

Can you tell me library code, which is working fine now. Thanks!

@Akarsh25 @bconway @Anh_Quan_Tong
I am trying to do a similar thing if you can help me please. I want to forward packets from gateway bridge to external MQTT server, and then decrypt messages there, knowing that OTAA is used. If that is possible, how to decrypt the packets and hence the payload? and how to get the nwkSkey and appSkey at the external end while they are not generated from the beginning?