Merge bitcoin/bitcoin#17211: Allow fundrawtransaction and walletcreatefundedpsbt to take external inputs

928af61cdb2c4de1c3d10e6fda13bbba5ca0bba9 allow send rpc take external inputs and solving data (Andrew Chow)
e39b5a5e7aa4d015257565ca79dc7b1f7a65e074 Tests for funding with external inputs (Andrew Chow)
38f5642cccf2b6708e58f5e2af5ecdcf752e61ec allow fundtx rpcs to work with external inputs (Andrew Chow)
d5cfb864ae16da62399bc97ab1ed54d32cf0cce9 Allow Coin Selection be able to take external inputs (Andrew Chow)
a00eb388e8046fe105666445dff6c91e8f8664cb Allow CInputCoin to also be constructed with COutPoint and CTxOut (Andrew Chow)

Pull request description:

  Currently `fundrawtransaction` and `walletcreatefundedpsbt` both do not allow external inputs as the wallet does not have the information necessary to estimate their fees.

  This PR adds an additional argument to both those RPCs which allows the user to specify solving data. This way, the wallet can use that solving data to estimate the size of those inputs. The solving data can be public keys, scripts, or descriptors.

ACKs for top commit:
  prayank23:
    reACK https://github.com/bitcoin/bitcoin/commit/928af61cdb2c4de1c3d10e6fda13bbba5ca0bba9
  meshcollider:
    Re-utACK 928af61cdb2c4de1c3d10e6fda13bbba5ca0bba9
  instagibbs:
    crACK 928af61cdb2c4de1c3d10e6fda13bbba5ca0bba9
  yanmaani:
    utACK 928af61.

Tree-SHA512: bc7a6ef8961a7f4971ea5985d75e2d6dc50c2a90b44c664a1c4b0f1be5c1c97823516358fdaab35771a4701dbefc0862127b1d0d4bfd02b4f20d2befa4434700

3 files changed, 139 insertions, 1 deletions

diff --git a/test/functional/rpc_fundrawtransaction.py b/test/functional/rpc_fundrawtransaction.py
index cda0ae0eeb..3b01506986 100755
--- a/test/functional/rpc_fundrawtransaction.py
+++ b/test/functional/rpc_fundrawtransaction.py
@@ -8,6 +8,7 @@ from decimal import Decimal
 from itertools import product
 
 from test_framework.descriptors import descsum_create
+from test_framework.key import ECKey
 from test_framework.test_framework import BitcoinTestFramework
 from test_framework.util import (
     assert_approx,
@@ -19,6 +20,7 @@ from test_framework.util import (
     count_bytes,
     find_vout_for_address,
 )
+from test_framework.wallet_util import bytes_to_wif
 
 
 def get_unspent(listunspent, amount):
@@ -132,6 +134,7 @@ class RawTransactionsTest(BitcoinTestFramework):
         self.test_subtract_fee_with_presets()
         self.test_transaction_too_large()
         self.test_include_unsafe()
+        self.test_external_inputs()
         self.test_22670()
 
     def test_change_position(self):
@@ -983,6 +986,56 @@ class RawTransactionsTest(BitcoinTestFramework):
         wallet.sendmany("", outputs)
         self.generate(self.nodes[0], 10)
         assert_raises_rpc_error(-4, "Transaction too large", recipient.fundrawtransaction, rawtx)
+        self.nodes[0].unloadwallet("large")
+
+    def test_external_inputs(self):
+        self.log.info("Test funding with external inputs")
+
+        eckey = ECKey()
+        eckey.generate()
+        privkey = bytes_to_wif(eckey.get_bytes())
+
+        self.nodes[2].createwallet("extfund")
+        wallet = self.nodes[2].get_wallet_rpc("extfund")
+
+        # Make a weird but signable script. sh(pkh()) descriptor accomplishes this
+        desc = descsum_create("sh(pkh({}))".format(privkey))
+        if self.options.descriptors:
+            res = self.nodes[0].importdescriptors([{"desc": desc, "timestamp": "now"}])
+        else:
+            res = self.nodes[0].importmulti([{"desc": desc, "timestamp": "now"}])
+        assert res[0]["success"]
+        addr = self.nodes[0].deriveaddresses(desc)[0]
+        addr_info = self.nodes[0].getaddressinfo(addr)
+
+        self.nodes[0].sendtoaddress(addr, 10)
+        self.nodes[0].sendtoaddress(wallet.getnewaddress(), 10)
+        self.nodes[0].generate(6)
+        ext_utxo = self.nodes[0].listunspent(addresses=[addr])[0]
+
+        # An external input without solving data should result in an error
+        raw_tx = wallet.createrawtransaction([ext_utxo], {self.nodes[0].getnewaddress(): 15})
+        assert_raises_rpc_error(-4, "Insufficient funds", wallet.fundrawtransaction, raw_tx)
+
+        # Error conditions
+        assert_raises_rpc_error(-5, "'not a pubkey' is not hex", wallet.fundrawtransaction, raw_tx, {"solving_data": {"pubkeys":["not a pubkey"]}})
+        assert_raises_rpc_error(-5, "'01234567890a0b0c0d0e0f' is not a valid public key", wallet.fundrawtransaction, raw_tx, {"solving_data": {"pubkeys":["01234567890a0b0c0d0e0f"]}})
+        assert_raises_rpc_error(-5, "'not a script' is not hex", wallet.fundrawtransaction, raw_tx, {"solving_data": {"scripts":["not a script"]}})
+        assert_raises_rpc_error(-8, "Unable to parse descriptor 'not a descriptor'", wallet.fundrawtransaction, raw_tx, {"solving_data": {"descriptors":["not a descriptor"]}})
+
+        # But funding should work when the solving data is provided
+        funded_tx = wallet.fundrawtransaction(raw_tx, {"solving_data": {"pubkeys": [addr_info['pubkey']], "scripts": [addr_info["embedded"]["scriptPubKey"]]}})
+        signed_tx = wallet.signrawtransactionwithwallet(funded_tx['hex'])
+        assert not signed_tx['complete']
+        signed_tx = self.nodes[0].signrawtransactionwithwallet(signed_tx['hex'])
+        assert signed_tx['complete']
+
+        funded_tx = wallet.fundrawtransaction(raw_tx, {"solving_data": {"descriptors": [desc]}})
+        signed_tx = wallet.signrawtransactionwithwallet(funded_tx['hex'])
+        assert not signed_tx['complete']
+        signed_tx = self.nodes[0].signrawtransactionwithwallet(signed_tx['hex'])
+        assert signed_tx['complete']
+        self.nodes[2].unloadwallet("extfund")
 
     def test_include_unsafe(self):
         self.log.info("Test fundrawtxn with unsafe inputs")
@@ -1017,6 +1070,7 @@ class RawTransactionsTest(BitcoinTestFramework):
         assert all((txin["txid"], txin["vout"]) in inputs for txin in tx_dec["vin"])
         signedtx = wallet.signrawtransactionwithwallet(fundedtx['hex'])
         assert wallet.testmempoolaccept([signedtx['hex']])[0]["allowed"]
+        self.nodes[0].unloadwallet("unsafe")
 
     def test_22670(self):
         # In issue #22670, it was observed that ApproximateBestSubset may
diff --git a/test/functional/rpc_psbt.py b/test/functional/rpc_psbt.py
index f330bbf1c3..6b5b2c6a0f 100755
--- a/test/functional/rpc_psbt.py
+++ b/test/functional/rpc_psbt.py
@@ -8,6 +8,8 @@
 from decimal import Decimal
 from itertools import product
 
+from test_framework.descriptors import descsum_create
+from test_framework.key import ECKey
 from test_framework.test_framework import BitcoinTestFramework
 from test_framework.util import (
     assert_approx,
@@ -16,6 +18,7 @@ from test_framework.util import (
     assert_raises_rpc_error,
     find_output,
 )
+from test_framework.wallet_util import bytes_to_wif
 
 import json
 import os
@@ -608,5 +611,42 @@ class PSBTTest(BitcoinTestFramework):
 
         assert_raises_rpc_error(-25, 'Inputs missing or spent', self.nodes[0].walletprocesspsbt, 'cHNidP8BAJoCAAAAAkvEW8NnDtdNtDpsmze+Ht2LH35IJcKv00jKAlUs21RrAwAAAAD/////S8Rbw2cO1020OmybN74e3Ysffkglwq/TSMoCVSzbVGsBAAAAAP7///8CwLYClQAAAAAWABSNJKzjaUb3uOxixsvh1GGE3fW7zQD5ApUAAAAAFgAUKNw0x8HRctAgmvoevm4u1SbN7XIAAAAAAAEAnQIAAAACczMa321tVHuN4GKWKRncycI22aX3uXgwSFUKM2orjRsBAAAAAP7///9zMxrfbW1Ue43gYpYpGdzJwjbZpfe5eDBIVQozaiuNGwAAAAAA/v///wIA+QKVAAAAABl2qRT9zXUVA8Ls5iVqynLHe5/vSe1XyYisQM0ClQAAAAAWABRmWQUcjSjghQ8/uH4Bn/zkakwLtAAAAAAAAQEfQM0ClQAAAAAWABRmWQUcjSjghQ8/uH4Bn/zkakwLtAAAAA==')
 
+        # Test that we can fund psbts with external inputs specified
+        eckey = ECKey()
+        eckey.generate()
+        privkey = bytes_to_wif(eckey.get_bytes())
+
+        # Make a weird but signable script. sh(pkh()) descriptor accomplishes this
+        desc = descsum_create("sh(pkh({}))".format(privkey))
+        if self.options.descriptors:
+            res = self.nodes[0].importdescriptors([{"desc": desc, "timestamp": "now"}])
+        else:
+            res = self.nodes[0].importmulti([{"desc": desc, "timestamp": "now"}])
+        assert res[0]["success"]
+        addr = self.nodes[0].deriveaddresses(desc)[0]
+        addr_info = self.nodes[0].getaddressinfo(addr)
+
+        self.nodes[0].sendtoaddress(addr, 10)
+        self.nodes[0].generate(6)
+        ext_utxo = self.nodes[0].listunspent(addresses=[addr])[0]
+
+        # An external input without solving data should result in an error
+        assert_raises_rpc_error(-4, "Insufficient funds", self.nodes[1].walletcreatefundedpsbt, [ext_utxo], {self.nodes[0].getnewaddress(): 10 + ext_utxo['amount']}, 0, {'add_inputs': True})
+
+        # But funding should work when the solving data is provided
+        psbt = self.nodes[1].walletcreatefundedpsbt([ext_utxo], {self.nodes[0].getnewaddress(): 15}, 0, {'add_inputs': True, "solving_data": {"pubkeys": [addr_info['pubkey']], "scripts": [addr_info["embedded"]["scriptPubKey"]]}})
+        signed = self.nodes[1].walletprocesspsbt(psbt['psbt'])
+        assert not signed['complete']
+        signed = self.nodes[0].walletprocesspsbt(signed['psbt'])
+        assert signed['complete']
+        self.nodes[0].finalizepsbt(signed['psbt'])
+
+        psbt = self.nodes[1].walletcreatefundedpsbt([ext_utxo], {self.nodes[0].getnewaddress(): 15}, 0, {'add_inputs': True, "solving_data":{"descriptors": [desc]}})
+        signed = self.nodes[1].walletprocesspsbt(psbt['psbt'])
+        assert not signed['complete']
+        signed = self.nodes[0].walletprocesspsbt(signed['psbt'])
+        assert signed['complete']
+        self.nodes[0].finalizepsbt(signed['psbt'])
+
 if __name__ == '__main__':
     PSBTTest().main()
diff --git a/test/functional/wallet_send.py b/test/functional/wallet_send.py
index aecdaf821f..7b23235945 100755
--- a/test/functional/wallet_send.py
+++ b/test/functional/wallet_send.py
@@ -9,6 +9,7 @@ from itertools import product
 
 from test_framework.authproxy import JSONRPCException
 from test_framework.descriptors import descsum_create
+from test_framework.key import ECKey
 from test_framework.test_framework import BitcoinTestFramework
 from test_framework.util import (
     assert_equal,
@@ -16,6 +17,7 @@ from test_framework.util import (
     assert_greater_than,
     assert_raises_rpc_error,
 )
+from test_framework.wallet_util import bytes_to_wif
 
 class WalletSendTest(BitcoinTestFramework):
     def set_test_params(self):
@@ -35,7 +37,7 @@ class WalletSendTest(BitcoinTestFramework):
                   conf_target=None, estimate_mode=None, fee_rate=None, add_to_wallet=None, psbt=None,
                   inputs=None, add_inputs=None, include_unsafe=None, change_address=None, change_position=None, change_type=None,
                   include_watching=None, locktime=None, lock_unspents=None, replaceable=None, subtract_fee_from_outputs=None,
-                  expect_error=None):
+                  expect_error=None, solving_data=None):
         assert (amount is None) != (data is None)
 
         from_balance_before = from_wallet.getbalances()["mine"]["trusted"]
@@ -94,6 +96,8 @@ class WalletSendTest(BitcoinTestFramework):
             options["replaceable"] = replaceable
         if subtract_fee_from_outputs is not None:
             options["subtract_fee_from_outputs"] = subtract_fee_from_outputs
+        if solving_data is not None:
+            options["solving_data"] = solving_data
 
         if len(options.keys()) == 0:
             options = None
@@ -476,6 +480,46 @@ class WalletSendTest(BitcoinTestFramework):
         res = self.test_send(from_wallet=w5, to_wallet=w0, amount=1, include_unsafe=True)
         assert res["complete"]
 
+        self.log.info("External outputs")
+        eckey = ECKey()
+        eckey.generate()
+        privkey = bytes_to_wif(eckey.get_bytes())
+
+        self.nodes[1].createwallet("extsend")
+        ext_wallet = self.nodes[1].get_wallet_rpc("extsend")
+        self.nodes[1].createwallet("extfund")
+        ext_fund = self.nodes[1].get_wallet_rpc("extfund")
+
+        # Make a weird but signable script. sh(pkh()) descriptor accomplishes this
+        desc = descsum_create("sh(pkh({}))".format(privkey))
+        if self.options.descriptors:
+            res = ext_fund.importdescriptors([{"desc": desc, "timestamp": "now"}])
+        else:
+            res = ext_fund.importmulti([{"desc": desc, "timestamp": "now"}])
+        assert res[0]["success"]
+        addr = self.nodes[0].deriveaddresses(desc)[0]
+        addr_info = ext_fund.getaddressinfo(addr)
+
+        self.nodes[0].sendtoaddress(addr, 10)
+        self.nodes[0].sendtoaddress(ext_wallet.getnewaddress(), 10)
+        self.nodes[0].generate(6)
+        ext_utxo = ext_fund.listunspent(addresses=[addr])[0]
+
+        # An external input without solving data should result in an error
+        self.test_send(from_wallet=ext_wallet, to_wallet=self.nodes[0], amount=15, inputs=[ext_utxo], add_inputs=True, psbt=True, include_watching=True, expect_error=(-4, "Insufficient funds"))
+
+        # But funding should work when the solving data is provided
+        res = self.test_send(from_wallet=ext_wallet, to_wallet=self.nodes[0], amount=15, inputs=[ext_utxo], add_inputs=True, psbt=True, include_watching=True, solving_data={"pubkeys": [addr_info['pubkey']], "scripts": [addr_info["embedded"]["scriptPubKey"]]})
+        signed = ext_wallet.walletprocesspsbt(res["psbt"])
+        signed = ext_fund.walletprocesspsbt(res["psbt"])
+        assert signed["complete"]
+        self.nodes[0].finalizepsbt(signed["psbt"])
+
+        res = self.test_send(from_wallet=ext_wallet, to_wallet=self.nodes[0], amount=15, inputs=[ext_utxo], add_inputs=True, psbt=True, include_watching=True, solving_data={"descriptors": [desc]})
+        signed = ext_wallet.walletprocesspsbt(res["psbt"])
+        signed = ext_fund.walletprocesspsbt(res["psbt"])
+        assert signed["complete"]
+        self.nodes[0].finalizepsbt(signed["psbt"])
 
 if __name__ == '__main__':
     WalletSendTest().main()