Thank you for your answer.
I do not think I made myself clear enough though. My objective is to decrypt a 802.15.4 packet sniffed and encrypted by a xbee s1 module. Of course, I know the key...
Normally a nonce is used and I don't know what it is. Also, I 'm not sure what Aes (CTR, CCM...) is used.
Someone know all the parameters to encrypt and decrypt a xbee s1 encrypted packet ?