keepkey cosigner in multisig fails to sign

[SomberNight]

On git master 4e60ced.

2-of-2 p2sh-multisig wallet (not segwit)
Cosigners: keepkey and xpub.

Electrum fails to sign the unsigned tx.
Tx is typical 1-in 2-out, with the non-change output being p2pkh, so nothing fancy.

Traceback (most recent call last):
  File "/home/user/wspace/electrum/gui/qt/util.py", line 579, in run
    result = task.task()
  File "/home/user/wspace/electrum/lib/wallet.py", line 1152, in sign_transaction
    k.sign_transaction(tx, password)
  File "/home/user/wspace/electrum/plugins/keepkey/plugin.py", line 59, in sign_transaction
    self.plugin.sign_transaction(self, tx, prev_tx, xpub_path)
  File "/home/user/wspace/electrum/plugins/keepkey/plugin.py", line 222, in sign_transaction
    inputs = self.tx_inputs(tx, True, keystore.is_segwit())
  File "/home/user/wspace/electrum/plugins/keepkey/plugin.py", line 270, in tx_inputs
    m=txin.get('num_sig'),
  File "/usr/local/lib/python3.5/dist-packages/protobuf-3.4.0-py3.5.egg/google/protobuf/internal/python_message.py", line 501, in init
    for val in field_value:
  File "/home/user/wspace/electrum/plugins/keepkey/plugin.py", line 264, in f
    node = self.ckd_public.deserialize(xpub)
  File "/home/user/.local/lib/python3.5/site-packages/keepkeylib/ckd_public.py", line 111, in deserialize
    raise Exception("Checksum failed")
Exception: Checksum failed

Unsigned tx (testnet):

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

$ pip3 show keepkey
Name: keepkey
Version: 4.0.0

Btw @kyuupichan already reported this a few days ago on IRC.

[kyuupichan]

This is a bug in keepkey libraries which can be fixed locally:

keepkey/python-keepkey#18

[nickmonad]

The fix related to the particular function in this issue has been resolved in the latest release of python-keepkey, v4.0.2. Please download and reattempt with the latest version.

There have also been reports of a potential SIGHASH_FORKID issue in the keepkey firmware when signing a multi-sig BCH transaction. I posted information about that issue here: keepkey/keepkey-firmware#35

If an electrum dev is available to take a look at that issue ^ and let us know what you think, we would be appreciative. The information I posted there leads me to believe that this is not an issue with the keepkey firmware, but verification of that would be helpful. Thanks!

[SomberNight]

I've just tested with python-keepkey 4.0.2, and it worked. Thanks.

There have also been reports of a potential SIGHASH_FORKID issue in the keepkey firmware when signing a multi-sig BCH transaction.

I don't know about the BCH issue, sorry. Consider opening an issue in https://github.com/fyookball/electrum

Closing, as the issue here is resolved.