Ledger : Remove warning on Segwit inputs and newer Bitcoin application, use ge…

[btchip]

…neric signing for P2SH inputs

[SomberNight]

I think it's worth it to just bump the min supported library version (and enforce it, now that you provide __version__), instead of making the code here more complicated (the logic is already hard to follow in some cases in sign_transaction). I've pushed some commits accordingly.

I have tested this with a Ledger Nano S with bitcoin app version 1.3.7 and 1.4.2, and it ~works.
I have tested spending p2pkh, p2wpkh-p2sh, p2wpkh, p2sh-multisig-2of2, p2wsh-p2sh-multisig-2of2, p2wsh-multisig-2of2 input scripts.

What does not work, and I think only with bitcoin app 1.4.2, is signing a segwit tx with multiple inputs. The device produces incorrect signatures. This should be unrelated from this PR I believe, and is probably a firmware (bitcoin app) bug.
So e.g. with a standard bip84 p2wpkh wallet, creating a 2-input tx fails (as in it will have incorrect signatures):

bitcoin-cli testmempoolaccept \[\"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\"\]
[
  {
    "txid": "3125124cd02281661909dc306a88e3a18ec66c5316ebb138051dc0466e979d32",
    "allowed": false,
    "reject-reason": "64: non-mandatory-script-verify-flag (Signature must be zero for failed CHECK(MULTI)SIG operation)"
  }
]

(but a 1-input tx works)
AFAICT this has already been reported at LedgerHQ/app-bitcoin#154

[SomberNight]

Besides that firmware bug, please take a look at the current state of the PR; and if you think it's ok, I will merge it.

[btchip]

Thanks for the updates and tests. All look fine to me, you can bump the library requirement to 0.1.30 which provides a workaround for the issue you mentioned and merge

[SomberNight]

Thanks. I confirm it's fixed with 0.1.30.