diff --git a/doc/descriptors.md b/doc/descriptors.md index 3b94ec03e4a..5e8e4a24b08 100644 --- a/doc/descriptors.md +++ b/doc/descriptors.md @@ -63,6 +63,7 @@ Output descriptors currently support: - `wsh(sortedmulti(1,xpub661MyMwAqRbcFW31YEwpkMuc5THy2PSt5bDMsktWQcFF8syAmRUapSCGu8ED9W6oDMSgv6Zz8idoc4a6mr8BDzTJY47LJhkJ8UB7WEGuduB/1/0/*,xpub69H7F5d8KSRgmmdJg2KhpAK8SR3DjMwAdkxj3ZuxV27CprR9LgpeyGmXUbC6wb7ERfvrnKZjXoUmmDznezpbZb7ap6r1D3tgFxHmwMkQTPH/0/0/*))` describes a set of *1-of-2* P2WSH multisig outputs where one multisig key is the *1/0/`i`* child of the first specified xpub and the other multisig key is the *0/0/`i`* child of the second specified xpub, and `i` is any number in a configurable range (`0-1000` by default). The order of public keys in the resulting witnessScripts is determined by the lexicographic order of the public keys at that index. - `tr(c6047f9441ed7d6d3045406e95c07cd85c778e4b8cef3ca7abac09b95c709ee5,{pk(fff97bd5755eeea420453a14355235d382f6472f8568a18b2f057a1460297556),pk(e493dbf1c10d80f3581e4904930b1404cc6c13900ee0758474fa94abe8c4cd13)})` describes a P2TR output with the `c6...` x-only pubkey as internal key, and two script paths. - `tr(c6047f9441ed7d6d3045406e95c07cd85c778e4b8cef3ca7abac09b95c709ee5,sortedmulti_a(2,2f8bde4d1a07209355b4a7250a5c5128e88b84bddc619ab7cba8d569b240efe4,5cbdf0646e5db4eaa398f365f2ea7a0e3d419b7e0330e39ce92bddedcac4f9bc))` describes a P2TR output with the `c6...` x-only pubkey as internal key, and a single `multi_a` script that needs 2 signatures with 2 specified x-only keys, which will be sorted lexicographically. +- `wsh(sortedmulti(2,[6f53d49c/44h/1h/0h]tpubDDjsCRDQ9YzyaAq9rspCfq8RZFrWoBpYnLxK6sS2hS2yukqSczgcYiur8Scx4Hd5AZatxTuzMtJQJhchufv1FRFanLqUP7JHwusSSpfcEp2/0/*,[e6807791/44h/1h/0h]tpubDDAfvogaaAxaFJ6c15ht7Tq6ZmiqFYfrSmZsHu7tHXBgnjMZSHAeHSwhvjARNA6Qybon4ksPksjRbPDVp7yXA1KjTjSd5x18KHqbppnXP1s/0/*,[367c9cfa/44h/1h/0h]tpubDDtPnSgWYk8dDnaDwnof4ehcnjuL5VoUt1eW2MoAed1grPHuXPDnkX1fWMvXfcz3NqFxPbhqNZ3QBdYjLz2hABeM9Z2oqMR1Gt2HHYDoCgh/0/*))#av0kxgw0` describes a *2-of-3* multisig. For brevity, the internal "change" descriptor accompanying the above external "receiving" descriptor is not included here, but it typically differs only in the xpub derivation steps, ending in `/1/*` for change addresses. ## Reference @@ -167,9 +168,9 @@ The basic steps are: the participant's signer wallet. Avoid reusing this wallet for any purpose other than signing transactions from the corresponding multisig we are about to create. Hint: extract the wallet's xpubs using `listdescriptors` and pick the one from the `pkh` descriptor since it's least likely to be accidentally reused (legacy addresses) - 2. Create a watch-only descriptor wallet (blank, private keys disabled). Now the multisig is created by importing the two descriptors: + 2. Create a watch-only descriptor wallet (blank, private keys disabled). Now the multisig is created by importing the external and internal descriptors: `wsh(sortedmulti(,XPUB1/0/*,XPUB2/0/*,…,XPUBN/0/*))` and `wsh(sortedmulti(,XPUB1/1/*,XPUB2/1/*,…,XPUBN/1/*))` - (one descriptor w/ `0` for receiving addresses and another w/ `1` for change). Every participant does this + (one descriptor w/ `0` for receiving addresses and another w/ `1` for change). Every participant does this. All key origin information (master key fingerprint and all derivation steps) should be included with xpubs for proper support of hardware devices / external signers 3. A receiving address is generated for the multisig. As a check to ensure step 2 was done correctly, every participant should verify they get the same addresses 4. Funds are sent to the resulting address diff --git a/test/functional/wallet_multisig_descriptor_psbt.py b/test/functional/wallet_multisig_descriptor_psbt.py index 68bf45f7e34..145912025f0 100755 --- a/test/functional/wallet_multisig_descriptor_psbt.py +++ b/test/functional/wallet_multisig_descriptor_psbt.py @@ -7,7 +7,6 @@ This is meant to be documentation as much as functional tests, so it is kept as simple and readable as possible. """ -from test_framework.address import base58_to_byte from test_framework.test_framework import BitcoinTestFramework from test_framework.util import ( assert_approx, @@ -30,10 +29,12 @@ class WalletMultisigDescriptorPSBTTest(BitcoinTestFramework): self.skip_if_no_sqlite() @staticmethod - def _get_xpub(wallet): + def _get_xpub(wallet, internal): """Extract the wallet's xpubs using `listdescriptors` and pick the one from the `pkh` descriptor since it's least likely to be accidentally reused (legacy addresses).""" - descriptor = next(filter(lambda d: d["desc"].startswith("pkh"), wallet.listdescriptors()["descriptors"])) - return descriptor["desc"].split("]")[-1].split("/")[0] + pkh_descriptor = next(filter(lambda d: d["desc"].startswith("pkh(") and d["internal"] == internal, wallet.listdescriptors()["descriptors"])) + # Keep all key origin information (master key fingerprint and all derivation steps) for proper support of hardware devices + # See section 'Key origin identification' in 'doc/descriptors.md' for more details... + return pkh_descriptor["desc"].split("pkh(")[1].split(")")[0] @staticmethod def _check_psbt(psbt, to, value, multisig): @@ -47,19 +48,13 @@ class WalletMultisigDescriptorPSBTTest(BitcoinTestFramework): amount += vout["value"] assert_approx(amount, float(value), vspan=0.001) - def participants_create_multisigs(self, xpubs): + def participants_create_multisigs(self, external_xpubs, internal_xpubs): """The multisig is created by importing the following descriptors. The resulting wallet is watch-only and every participant can do this.""" - # some simple validation - assert_equal(len(xpubs), self.N) - # a sanity-check/assertion, this will throw if the base58 checksum of any of the provided xpubs are invalid - for xpub in xpubs: - base58_to_byte(xpub) - for i, node in enumerate(self.nodes): node.createwallet(wallet_name=f"{self.name}_{i}", blank=True, descriptors=True, disable_private_keys=True) multisig = node.get_wallet_rpc(f"{self.name}_{i}") - external = multisig.getdescriptorinfo(f"wsh(sortedmulti({self.M},{f'/0/*,'.join(xpubs)}/0/*))") - internal = multisig.getdescriptorinfo(f"wsh(sortedmulti({self.M},{f'/1/*,'.join(xpubs)}/1/*))") + external = multisig.getdescriptorinfo(f"wsh(sortedmulti({self.M},{f','.join(external_xpubs)}))") + internal = multisig.getdescriptorinfo(f"wsh(sortedmulti({self.M},{f','.join(internal_xpubs)}))") result = multisig.importdescriptors([ { # receiving addresses (internal: False) "desc": external["descriptor"], @@ -93,10 +88,10 @@ class WalletMultisigDescriptorPSBTTest(BitcoinTestFramework): } self.log.info("Generate and exchange xpubs...") - xpubs = [self._get_xpub(signer) for signer in participants["signers"]] + external_xpubs, internal_xpubs = [[self._get_xpub(signer, internal) for signer in participants["signers"]] for internal in [False, True]] self.log.info("Every participant imports the following descriptors to create the watch-only multisig...") - participants["multisigs"] = list(self.participants_create_multisigs(xpubs)) + participants["multisigs"] = list(self.participants_create_multisigs(external_xpubs, internal_xpubs)) self.log.info("Check that every participant's multisig generates the same addresses...") for _ in range(10): # we check that the first 10 generated addresses are the same for all participant's multisigs