lwm2m with dtls: multiple psk keys?

asked 2018-08-06 14:20:13 +0000

I'm analysing lwm2m sessions with dtls (psk keys) and I would need that wireshark helps me in decoding this scenario:

the client starts handshake with bootstrap server:

I know which is the psk between client and server, so I configure it in Preferences --> Protocol --> DTLS --> Pre-Shared-Key

the handshake is ok,

the bootstrap server provides the DM server psk key in Coap "PUT /0/1 resource #5" packet:

I have to copy the value of this key, remove the ":" characters and configure the new key in Preferences --> Protocol --> DTLS --> Pre-Shared-Key, overwritting the bootstrap key.

  1. is there a way to avoid this annoying procedure?
  2. is there an automatic procedure or a script?

now I'm able to decrypt the communication between client and DM server, but not with bootstrap one.

  1. the text box of Preferences --> Protocol --> DTLS --> Pre-Shared-Key could become a combobox in order to store the last used keys, or automatically fill with the recognized keys (from Coap "PUT /0/n resource #5" packets).

the bootstrap server provides also a second DM server psk key, so I have to change again the psk key to decript the communication between client and DM2, so I lost the decrypted communication between client and DM...

it's quite annoying...

Regards Giuseppe Melis

edit retag flag offensive close merge delete

Comments

Support for multiple DTLS PSK (just like the existing support for multiple RSA DTLS keys) would be useful for me as well.

mfalkvidd gravatar imagemfalkvidd ( 2019-09-19 13:39:04 +0000 )edit