BitBoxSwiss / bitbox02-firmware

Firmware code of the BitBox02 hardware wallet
https://bitbox.swiss/bitbox02
Apache License 2.0
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bitcoin: allow multisig at arbitrary keypaths #1223

Closed benma closed 3 weeks ago

benma commented 3 weeks ago

Before, we would restrict the account-level keypaths for multisig to be:

Since the keypath is verified by the user and the coin network is confirmed for every receive/send, ransom and isolation bypass attacks are mitigated sufficiently, and we can lift this restriction. Note that for wallet policies (of which multisig is a subset of), arbitrary keypaths are already allowed.

When exporting an xpub, we furthermore warned about "unusual" keypaths. In addition to the above keypaths, we also allow exporting the xpub at m/45' without warning, as this path is used by Unchained for their vaults.