Merge #14477: Add ability to convert solvability info to descriptor

109699dd33 Add release notes (Pieter Wuille)
b65326b562 Add matching descriptors to scantxoutset output + tests (Pieter Wuille)
16203d5df7 Add descriptors to listunspent and getaddressinfo + tests (Pieter Wuille)
9b2a25b13f Add tests for InferDescriptor and Descriptor::IsSolvable (Pieter Wuille)
225bf3e3b0 Add Descriptor::IsSolvable() to distinguish addr/raw from others (Pieter Wuille)
4d78bd93b5 Add support for inferring descriptors from scripts (Pieter Wuille)

Pull request description:

  This PR adds functionality to convert a script to a descriptor, given a `SigningProvider` with the relevant information about public keys and redeemscripts/witnessscripts.

  The feature is exposed in `listunspent`, `getaddressinfo`, and `scantxoutset` whenever these calls are applied to solvable outputs/addresses.

  This is not very useful on its own, though when we add RPCs to import descriptors, or sign PSBTs using descriptors, these strings become a compact and standalone way of conveying everything necessary to sign an output (excluding private keys).

  Unit tests and rudimentary RPC tests are included (more relevant tests can be added once RPCs support descriptors).

  Fixes #14503.

Tree-SHA512: cb36b84a3e0200375b7e06a98c7e750cfaf95cf5de132cad59f7ec3cbd201f739427de0dc108f515be7aca203652089fbf5f24ed283d4553bddf23a3224ab31f

2 files changed, 64 insertions, 0 deletions

diff --git a/test/functional/rpc_scantxoutset.py b/test/functional/rpc_scantxoutset.py
index 881b839a4e..11b4db6ec5 100755
--- a/test/functional/rpc_scantxoutset.py
+++ b/test/functional/rpc_scantxoutset.py
@@ -10,6 +10,9 @@ from decimal import Decimal
 import shutil
 import os
 
+def descriptors(out):
+    return sorted(u['desc'] for u in out['unspents'])
+
 class ScantxoutsetTest(BitcoinTestFramework):
     def set_test_params(self):
         self.num_nodes = 1
@@ -93,5 +96,10 @@ class ScantxoutsetTest(BitcoinTestFramework):
         assert_equal(self.nodes[0].scantxoutset("start", [ {"desc": "combo(tpubD6NzVbkrYhZ4WaWSyoBvQwbpLkojyoTZPRsgXELWz3Popb3qkjcJyJUGLnL4qHHoQvao8ESaAstxYSnhyswJ76uZPStJRJCTKvosUCJZL5B/1/1/*)", "range": 1499}])['total_amount'], Decimal("12.288"))
         assert_equal(self.nodes[0].scantxoutset("start", [ {"desc": "combo(tpubD6NzVbkrYhZ4WaWSyoBvQwbpLkojyoTZPRsgXELWz3Popb3qkjcJyJUGLnL4qHHoQvao8ESaAstxYSnhyswJ76uZPStJRJCTKvosUCJZL5B/1/1/*)", "range": 1500}])['total_amount'], Decimal("28.672"))
 
+        # Test the reported descriptors for a few matches
+        assert_equal(descriptors(self.nodes[0].scantxoutset("start", [ {"desc": "combo(tprv8ZgxMBicQKsPd7Uf69XL1XwhmjHopUGep8GuEiJDZmbQz6o58LninorQAfcKZWARbtRtfnLcJ5MQ2AtHcQJCCRUcMRvmDUjyEmNUWwx8UbK/0h/0'/*)", "range": 1499}])), ["pkh([0c5f9a1e/0'/0'/0]026dbd8b2315f296d36e6b6920b1579ca75569464875c7ebe869b536a7d9503c8c)", "pkh([0c5f9a1e/0'/0'/1]033e6f25d76c00bedb3a8993c7d5739ee806397f0529b1b31dda31ef890f19a60c)"])
+        assert_equal(descriptors(self.nodes[0].scantxoutset("start", [ "combo(tprv8ZgxMBicQKsPd7Uf69XL1XwhmjHopUGep8GuEiJDZmbQz6o58LninorQAfcKZWARbtRtfnLcJ5MQ2AtHcQJCCRUcMRvmDUjyEmNUWwx8UbK/1/1/0)"])), ["pkh([0c5f9a1e/1/1/0]03e1c5b6e650966971d7e71ef2674f80222752740fc1dfd63bbbd220d2da9bd0fb)"])
+        assert_equal(descriptors(self.nodes[0].scantxoutset("start", [ {"desc": "combo(tpubD6NzVbkrYhZ4WaWSyoBvQwbpLkojyoTZPRsgXELWz3Popb3qkjcJyJUGLnL4qHHoQvao8ESaAstxYSnhyswJ76uZPStJRJCTKvosUCJZL5B/1/1/*)", "range": 1500}])), ['pkh([0c5f9a1e/1/1/0]03e1c5b6e650966971d7e71ef2674f80222752740fc1dfd63bbbd220d2da9bd0fb)', 'pkh([0c5f9a1e/1/1/1500]03832901c250025da2aebae2bfb38d5c703a57ab66ad477f9c578bfbcd78abca6f)', 'pkh([0c5f9a1e/1/1/1]030d820fc9e8211c4169be8530efbc632775d8286167afd178caaf1089b77daba7)'])
+
 if __name__ == '__main__':
     ScantxoutsetTest().main()
diff --git a/test/functional/wallet_address_types.py b/test/functional/wallet_address_types.py
index 0f75045c9d..bafa556aad 100755
--- a/test/functional/wallet_address_types.py
+++ b/test/functional/wallet_address_types.py
@@ -99,6 +99,8 @@ class AddressTypeTest(BitcoinTestFramework):
         """Run sanity checks on an address."""
         info = self.nodes[node].getaddressinfo(address)
         assert(self.nodes[node].validateaddress(address)['isvalid'])
+        assert_equal(info.get('solvable'), True)
+
         if not multisig and typ == 'legacy':
             # P2PKH
             assert(not info['isscript'])
@@ -146,6 +148,47 @@ class AddressTypeTest(BitcoinTestFramework):
             # Unknown type
             assert(False)
 
+    def test_desc(self, node, address, multisig, typ, utxo):
+        """Run sanity checks on a descriptor reported by getaddressinfo."""
+        info = self.nodes[node].getaddressinfo(address)
+        assert('desc' in info)
+        assert_equal(info['desc'], utxo['desc'])
+        assert(self.nodes[node].validateaddress(address)['isvalid'])
+
+        # Use a ridiculously roundabout way to find the key origin info through
+        # the PSBT logic. However, this does test consistency between the PSBT reported
+        # fingerprints/paths and the descriptor logic.
+        psbt = self.nodes[node].createpsbt([{'txid':utxo['txid'], 'vout':utxo['vout']}],[{address:0.00010000}])
+        psbt = self.nodes[node].walletprocesspsbt(psbt, False, "ALL", True)
+        decode = self.nodes[node].decodepsbt(psbt['psbt'])
+        key_descs = {}
+        for deriv in decode['inputs'][0]['bip32_derivs']:
+            assert_equal(len(deriv['master_fingerprint']), 8)
+            assert_equal(deriv['path'][0], 'm')
+            key_descs[deriv['pubkey']] = '[' + deriv['master_fingerprint'] + deriv['path'][1:] + ']' + deriv['pubkey']
+
+        if not multisig and typ == 'legacy':
+            # P2PKH
+            assert_equal(info['desc'], "pkh(%s)" % key_descs[info['pubkey']])
+        elif not multisig and typ == 'p2sh-segwit':
+            # P2SH-P2WPKH
+            assert_equal(info['desc'], "sh(wpkh(%s))" % key_descs[info['pubkey']])
+        elif not multisig and typ == 'bech32':
+            # P2WPKH
+            assert_equal(info['desc'], "wpkh(%s)" % key_descs[info['pubkey']])
+        elif typ == 'legacy':
+            # P2SH-multisig
+            assert_equal(info['desc'], "sh(multi(2,%s,%s))" % (key_descs[info['pubkeys'][0]], key_descs[info['pubkeys'][1]]))
+        elif typ == 'p2sh-segwit':
+            # P2SH-P2WSH-multisig
+            assert_equal(info['desc'], "sh(wsh(multi(2,%s,%s)))" % (key_descs[info['embedded']['pubkeys'][0]], key_descs[info['embedded']['pubkeys'][1]]))
+        elif typ == 'bech32':
+            # P2WSH-multisig
+            assert_equal(info['desc'], "wsh(multi(2,%s,%s))" % (key_descs[info['pubkeys'][0]], key_descs[info['pubkeys'][1]]))
+        else:
+            # Unknown type
+            assert(False)
+
     def test_change_output_type(self, node_sender, destinations, expected_type):
         txid = self.nodes[node_sender].sendmany(dummy="", amounts=dict.fromkeys(destinations, 0.001))
         raw_tx = self.nodes[node_sender].getrawtransaction(txid)
@@ -198,6 +241,7 @@ class AddressTypeTest(BitcoinTestFramework):
             self.log.debug("Old balances are {}".format(old_balances))
             to_send = (old_balances[from_node] / 101).quantize(Decimal("0.00000001"))
             sends = {}
+            addresses = {}
 
             self.log.debug("Prepare sends")
             for n, to_node in enumerate(range(from_node, from_node + 4)):
@@ -228,6 +272,7 @@ class AddressTypeTest(BitcoinTestFramework):
 
                 # Output entry
                 sends[address] = to_send * 10 * (1 + n)
+                addresses[to_node] = (address, typ)
 
             self.log.debug("Sending: {}".format(sends))
             self.nodes[from_node].sendmany("", sends)
@@ -244,6 +289,17 @@ class AddressTypeTest(BitcoinTestFramework):
             self.nodes[5].generate(1)
             sync_blocks(self.nodes)
 
+            # Verify that the receiving wallet contains a UTXO with the expected address, and expected descriptor
+            for n, to_node in enumerate(range(from_node, from_node + 4)):
+                to_node %= 4
+                found = False
+                for utxo in self.nodes[to_node].listunspent():
+                    if utxo['address'] == addresses[to_node][0]:
+                        found = True
+                        self.test_desc(to_node, addresses[to_node][0], multisig, addresses[to_node][1], utxo)
+                        break
+                assert found
+
             new_balances = self.get_balances()
             self.log.debug("Check new balances: {}".format(new_balances))
             # We don't know what fee was set, so we can only check bounds on the balance of the sending node