janjongboom / lorawan-fota-signing-tool Goto Github PK

Hi! I've been studying your FUOTA mechanism from the security perspective and first of all thanks for the hard work!

For what I understood, what's sent to the device is the binary update (full binary or diff) plus a manifest, and the manifest contains:

• Signature length + Signature
• manufacturerUUID, deviceClassUUID,
• versionBuffer: derived from a timestamp
• isDiffBuffer: seems to be a bool

Since the versionBuffer field in the manifest is not signed, it makes the FUOTA mechanism susceptible to replay attacks. This is, an attacker that previously sniffed a FUOTA is able to replay it, which can lead into a software downgrade.

Maybe the simplest approach to get around this problem is to use incremental versions and sign the version field as well? Let me know your thoughts, thanks.

I need to create a public/private key pair using Node.js 8. I have installed lorawan-fuota-signing-tool and gave the command "lorawan-fota-signing-tool create-keypair -d example.com -m awesome-2000" to generate keypair. An error occured as in the attachment and no files are generated in the folder .fota-keys. When I try further to generate keypair, error is displayed that overwriting of existing certificates is not possible.

I would also like to confirm if the domain name and device model name are specific or can be given by the user. I have given them as example.com and awesome-2000 currently.

Hi,
I think there is a problem in encode_file.py from line 109 as follows:

    first=1
    for k in range(data_row_count):
      if(templine[k]==1):
        if(first==1):
          for m in range(fragment_size):
            data_rows[i][m] = data_rows[k][m]
          first = 0
        else:
          for m in range(fragment_size):
            data_rows[i][m] = data_rows[i][m] ^ data_rows[k][m]

It may be modified as follows:

    for k in range(data_row_count):
      if(templine[k]==1):
          for m in range(fragment_size):
            data_rows[i][m] = data_rows[i][m] ^ data_rows[k][m]

If you disgree with it, could you tell me the reason.

Could not open first file \root\C:\path\to\update.bin

Looks like the "\root" in front of C: is causing an issue on windows

This failure happens when applying the delta update

Expected ESC but got EF
Positions are, source=0 patch=1 new=0
[WARN][LWUC]: apply_delta_update failed 1_

I've tracked down the issue to bad format of the diff returned by the fota-lorawan-signing-tool.
Looking at the implementation, the diff is in the stdout returned by spawnSync(jdiff.js) and for some reason it's not correct; However, when the jdiff command is run with the outfile option set, the diff in the outfile is correct.

I changed the tool to pass jdiff an outfile, and to get the diff from the file. With this change, delta updates are now working for me.