Merge #16528: Native Descriptor Wallets using DescriptorScriptPubKeyMan

223588b1bbc63dc57098bbd0baa48635e0cc0b82 Add a --descriptors option to various tests (Andrew Chow)
869f7ab30aeb4d7fbd563c535b55467a8a0430cf tests: Add RPCOverloadWrapper which overloads some disabled RPCs (Andrew Chow)
cf060628590fab87d73f278e744d70ef2d5d81db Correctly check for default wallet (Andrew Chow)
886e0d75f5fea2421190aa4812777d89f68962cc Implement CWallet::IsSpentKey for non-LegacySPKMans (Andrew Chow)
3c19fdd2a2fd5394fcfa75b2ba84ab2277cbdabf Return error when no ScriptPubKeyMan is available for specified type (Andrew Chow)
388ba94231f2f10a0be751c562cdd4650510a90a Change wallet_encryption.py to use signmessage instead of dumpprivkey (Andrew Chow)
1346e14831489f9c8f53a08f9dfed61d55d53c6f Functional tests for descriptor wallets (Andrew Chow)
f193ea889ddb53d9a5c47647966681d525e38368 add importdescriptors RPC and tests for native descriptor wallets (Hugo Nguyen)
ce24a944940019185efebcc5d85eac458ed26016 Add IsLegacy to CWallet so that the GUI knows whether to show watchonly (Andrew Chow)
1cb42b22b11c27e64462afc25a94b2fc50bfa113 Generate new descriptors when encrypting (Andrew Chow)
82ae02b1656819f4bd5023b8955447e1d4ea8692 Be able to create new wallets with DescriptorScriptPubKeyMans as backing (Andrew Chow)
b713baa75a62335ab9c0eed9ef76a95bfec30668 Implement GetMetadata in DescriptorScriptPubKeyMan (Andrew Chow)
8b9603bd0b443e2f7984eb72bf2e21cf02af0bcb Change GetMetadata to use unique_ptr<CKeyMetadata> (Andrew Chow)
72a9540df96ffdb94f039b9c14eaacdc7d961196 Implement FillPSBT in DescriptorScriptPubKeyMan (Andrew Chow)
84b4978c02102171775c77a45f6ec198930f0a88 Implement SignMessage for descriptor wallets (Andrew Chow)
bde7c9fa38775a81d53ac0484fa9c98076a0c7d1 Implement SignTransaction in DescriptorScriptPubKeyMan (Andrew Chow)
d50c8ddd4190f20bf0debd410348b73408ec3143 Implement GetSolvingProvider for DescriptorScriptPubKeyMan (Andrew Chow)
f1ca5feb4ad668a3e1ae543d0addd5f483f1a88f Implement GetKeypoolOldestTime and only display it if greater than 0 (Andrew Chow)
586b57a9a6b4b12a78f792785b63a5a1743bce0c Implement ReturnDestination in DescriptorScriptPubKeyMan (Andrew Chow)
f866957979c23cefd41efa9dae9e53b9177818dc Implement GetReservedDestination in DescriptorScriptPubKeyMan (Andrew Chow)
a775f7c7fd0b9094fcbeee6ba92206d5bbb19164 Implement Unlock and Encrypt in DescriptorScriptPubKeyMan (Andrew Chow)
bfdd0734869a22217c15858d7a76d0dacc2ebc86 Implement GetNewDestination for DescriptorScriptPubKeyMan (Andrew Chow)
58c7651821b0eeff0a99dc61d78d2e9e07986580 Implement TopUp in DescriptorScriptPubKeyMan (Andrew Chow)
e014886a342508f7c8d80323eee9a5f314eaf94c Implement SetupGeneration for DescriptorScriptPubKeyMan (Andrew Chow)
46dfb99768e7d03a3cf552812d5b41ceaebc06be Implement writing descriptorkeys, descriptorckeys, and descriptors to wallet file (Andrew Chow)
4cb9b69be031e1dc65d8964794781b347fd948f5 Implement several simple functions in DescriptorScriptPubKeyMan (Andrew Chow)
d1ec3e4f19487b4b100f80ad02eac063c571777d Add IsSingleType to Descriptors (Andrew Chow)
953feb3d2724f5398dd48990c4957a19313d2c8c Implement loading of keys for DescriptorScriptPubKeyMan (Andrew Chow)
2363e9fcaa41b68bf11153f591b95f2d41ff9a1a Load the descriptor cache from the wallet file (Andrew Chow)
46c46aebb7943e1e2e96755e94dc6c197920bf75 Implement GetID for DescriptorScriptPubKeyMan (Andrew Chow)
ec2f9e1178c8e38c0a5ca063fe81adac8f916348 Implement IsHDEnabled in DescriptorScriptPubKeyMan (Andrew Chow)
741122d4c1a62ced3e96d16d67f4eeb3a6522d99 Implement MarkUnusedAddresses in DescriptorScriptPubKeyMan (Andrew Chow)
2db7ca765c8fb2c71dd6f7c4f29ad70e68ff1720 Implement IsMine for DescriptorScriptPubKeyMan (Andrew Chow)
db7177af8c159abbcc209f2caafcd45d54c181c5 Add LoadDescriptorScriptPubKeyMan and SetActiveScriptPubKeyMan to CWallet (Andrew Chow)
78f8a92910d34247fa5d04368338c598d9908267 Implement SetType in DescriptorScriptPubKeyMan (Andrew Chow)
834de0300cde57ca3f662fb7aa5b1bdaed68bc8f Store WalletDescriptor in DescriptorScriptPubKeyMan (Andrew Chow)
d8132669e10c1db9ae0c2ea0d3f822d7d2f01345 Add a lock cs_desc_man for DescriptorScriptPubKeyMan (Andrew Chow)
3194a7f88ac1a32997b390b4f188c4b6a4af04a5 Introduce WalletDescriptor class (Andrew Chow)
6b13cd3fa854dfaeb9e269bff3d67cacc0e5b5dc Create LegacyScriptPubKeyMan when not a descriptor wallet (Andrew Chow)
aeac157c9dc141546b45e06ba9c2e641ad86083f Return nullptr from GetLegacyScriptPubKeyMan if descriptor wallet (Andrew Chow)
96accc73f067c7c95946e9932645dd821ef67f63 Add WALLET_FLAG_DESCRIPTORS (Andrew Chow)
6b8119af53ee2fdb4c4b5b24b4e650c0dc3bd27c Introduce DescriptorScriptPubKeyMan as a dummy class (Andrew Chow)
06620302c713cae65ee8e4ff9302e4c88e2a1285 Introduce SetType function to tell ScriptPubKeyMans the type and internal-ness of it (Andrew Chow)

Pull request description:

  Introducing the wallet of the glorious future (again): native descriptor wallets. With native descriptor wallets, addresses are generated from descriptors. Instead of generating keys and deriving addresses from keys, addresses come from the scriptPubKeys produced by a descriptor. Native descriptor wallets will be optional for now and can only be created by using `createwallet`.

  Descriptor wallets will store descriptors, master keys from the descriptor, and descriptor cache entries. Keys are derived from descriptors on the fly. In order to allow choosing different address types, 6 descriptors are needed for normal use. There is a pair of primary and change descriptors for each of the 3 address types. With the default keypool size of 1000, each descriptor has 1000 scriptPubKeys and descriptor cache entries pregenerated. This has a side effect of making wallets large since 6000 pubkeys are written to the wallet by default, instead of the current 2000. scriptPubKeys are kept only in memory and are generated every time a descriptor is loaded. By default, we use the standard BIP 44, 49, 84 derivation paths with an external and internal derivation chain for each.

  Descriptors can also be imported with a new `importdescriptors` RPC.

  Native descriptor wallets use the `ScriptPubKeyMan` interface introduced in #16341 to add a `DescriptorScriptPubKeyMan`. This defines a different IsMine which uses the simpler model of "does this scriptPubKey exist in this wallet". Furthermore, `DescriptorScriptPubKeyMan` does not have watchonly, so with native descriptor wallets, it is not possible to have a wallet with both watchonly and non-watchonly things. Rather a wallet with `disable_private_keys` needs to be used for watchonly things.

  A `--descriptor` option was added to some tests (`wallet_basic.py`, `wallet_encryption.py`, `wallet_keypool.py`, `wallet_keypool_topup.py`, and `wallet_labels.py`) to allow for these tests to use descriptor wallets. Additionally, several RPCs are disabled for descriptor wallets (`importprivkey`, `importpubkey`, `importaddress`, `importmulti`, `addmultisigaddress`, `dumpprivkey`, `dumpwallet`, `importwallet`, and `sethdseed`).

ACKs for top commit:
  Sjors:
    utACK 223588b1bbc63dc57098bbd0baa48635e0cc0b82 (rebased, nits addressed)
  jonatack:
    Code review re-ACK 223588b1bbc63dc57098bbd0baa48635e0cc0b82.
  fjahr:
    re-ACK 223588b1bbc63dc57098bbd0baa48635e0cc0b82
  instagibbs:
    light re-ACK 223588b
  meshcollider:
    Code review ACK 223588b1bbc63dc57098bbd0baa48635e0cc0b82

Tree-SHA512: 59bc52aeddbb769ed5f420d5d240d8137847ac821b588eb616b34461253510c1717d6a70bab8765631738747336ae06f45ba39603ccd17f483843e5ed9a90986

1 files changed, 294 insertions, 0 deletions

diff --git a/src/wallet/rpcdump.cpp b/src/wallet/rpcdump.cpp
index 86e4e06673..128de52b58 100644
--- a/src/wallet/rpcdump.cpp
+++ b/src/wallet/rpcdump.cpp
@@ -1458,3 +1458,297 @@ UniValue importmulti(const JSONRPCRequest& mainRequest)
 
     return response;
 }
+
+static UniValue ProcessDescriptorImport(CWallet * const pwallet, const UniValue& data, const int64_t timestamp) EXCLUSIVE_LOCKS_REQUIRED(pwallet->cs_wallet)
+{
+    UniValue warnings(UniValue::VARR);
+    UniValue result(UniValue::VOBJ);
+
+    try {
+        if (!data.exists("desc")) {
+            throw JSONRPCError(RPC_INVALID_PARAMETER, "Descriptor not found.");
+        }
+
+        const std::string& descriptor = data["desc"].get_str();
+        const bool active = data.exists("active") ? data["active"].get_bool() : false;
+        const bool internal = data.exists("internal") ? data["internal"].get_bool() : false;
+        const std::string& label = data.exists("label") ? data["label"].get_str() : "";
+
+        // Parse descriptor string
+        FlatSigningProvider keys;
+        std::string error;
+        auto parsed_desc = Parse(descriptor, keys, error, /* require_checksum = */ true);
+        if (!parsed_desc) {
+            throw JSONRPCError(RPC_INVALID_ADDRESS_OR_KEY, error);
+        }
+
+        // Range check
+        int64_t range_start = 0, range_end = 1, next_index = 0;
+        if (!parsed_desc->IsRange() && data.exists("range")) {
+            throw JSONRPCError(RPC_INVALID_PARAMETER, "Range should not be specified for an un-ranged descriptor");
+        } else if (parsed_desc->IsRange()) {
+            if (data.exists("range")) {
+                auto range = ParseDescriptorRange(data["range"]);
+                range_start = range.first;
+                range_end = range.second + 1; // Specified range end is inclusive, but we need range end as exclusive
+            } else {
+                warnings.push_back("Range not given, using default keypool range");
+                range_start = 0;
+                range_end = gArgs.GetArg("-keypool", DEFAULT_KEYPOOL_SIZE);
+            }
+            next_index = range_start;
+
+            if (data.exists("next_index")) {
+                next_index = data["next_index"].get_int64();
+                // bound checks
+                if (next_index < range_start || next_index >= range_end) {
+                    throw JSONRPCError(RPC_INVALID_PARAMETER, "next_index is out of range");
+                }
+            }
+        }
+
+        // Active descriptors must be ranged
+        if (active && !parsed_desc->IsRange()) {
+            throw JSONRPCError(RPC_INVALID_PARAMETER, "Active descriptors must be ranged");
+        }
+
+        // Ranged descriptors should not have a label
+        if (data.exists("range") && data.exists("label")) {
+            throw JSONRPCError(RPC_INVALID_PARAMETER, "Ranged descriptors should not have a label");
+        }
+
+        // Internal addresses should not have a label either
+        if (internal && data.exists("label")) {
+            throw JSONRPCError(RPC_INVALID_PARAMETER, "Internal addresses should not have a label");
+        }
+
+        // Combo descriptor check
+        if (active && !parsed_desc->IsSingleType()) {
+            throw JSONRPCError(RPC_WALLET_ERROR, "Combo descriptors cannot be set to active");
+        }
+
+        // If the wallet disabled private keys, abort if private keys exist
+        if (pwallet->IsWalletFlagSet(WALLET_FLAG_DISABLE_PRIVATE_KEYS) && !keys.keys.empty()) {
+            throw JSONRPCError(RPC_WALLET_ERROR, "Cannot import private keys to a wallet with private keys disabled");
+        }
+
+        // Need to ExpandPrivate to check if private keys are available for all pubkeys
+        FlatSigningProvider expand_keys;
+        std::vector<CScript> scripts;
+        parsed_desc->Expand(0, keys, scripts, expand_keys);
+        parsed_desc->ExpandPrivate(0, keys, expand_keys);
+
+        // Check if all private keys are provided
+        bool have_all_privkeys = !expand_keys.keys.empty();
+        for (const auto& entry : expand_keys.origins) {
+            const CKeyID& key_id = entry.first;
+            CKey key;
+            if (!expand_keys.GetKey(key_id, key)) {
+                have_all_privkeys = false;
+                break;
+            }
+        }
+
+        // If private keys are enabled, check some things.
+        if (!pwallet->IsWalletFlagSet(WALLET_FLAG_DISABLE_PRIVATE_KEYS)) {
+           if (keys.keys.empty()) {
+                throw JSONRPCError(RPC_WALLET_ERROR, "Cannot import descriptor without private keys to a wallet with private keys enabled");
+           }
+           if (!have_all_privkeys) {
+               warnings.push_back("Not all private keys provided. Some wallet functionality may return unexpected errors");
+           }
+        }
+
+        WalletDescriptor w_desc(std::move(parsed_desc), timestamp, range_start, range_end, next_index);
+
+        // Check if the wallet already contains the descriptor
+        auto existing_spk_manager = pwallet->GetDescriptorScriptPubKeyMan(w_desc);
+        if (existing_spk_manager) {
+            LOCK(existing_spk_manager->cs_desc_man);
+            if (range_start > existing_spk_manager->GetWalletDescriptor().range_start) {
+                throw JSONRPCError(RPC_INVALID_PARAMS, strprintf("range_start can only decrease; current range = [%d,%d]", existing_spk_manager->GetWalletDescriptor().range_start, existing_spk_manager->GetWalletDescriptor().range_end));
+            }
+        }
+
+        // Add descriptor to the wallet
+        auto spk_manager = pwallet->AddWalletDescriptor(w_desc, keys, label);
+        if (spk_manager == nullptr) {
+            throw JSONRPCError(RPC_WALLET_ERROR, strprintf("Could not add descriptor '%s'", descriptor));
+        }
+
+        // Set descriptor as active if necessary
+        if (active) {
+            if (!w_desc.descriptor->GetOutputType()) {
+                warnings.push_back("Unknown output type, cannot set descriptor to active.");
+            } else {
+                pwallet->SetActiveScriptPubKeyMan(spk_manager->GetID(), *w_desc.descriptor->GetOutputType(), internal);
+            }
+        }
+
+        result.pushKV("success", UniValue(true));
+    } catch (const UniValue& e) {
+        result.pushKV("success", UniValue(false));
+        result.pushKV("error", e);
+    } catch (...) {
+        result.pushKV("success", UniValue(false));
+
+        result.pushKV("error", JSONRPCError(RPC_MISC_ERROR, "Missing required fields"));
+    }
+    if (warnings.size()) result.pushKV("warnings", warnings);
+    return result;
+}
+
+UniValue importdescriptors(const JSONRPCRequest& main_request) {
+    // Acquire the wallet
+    std::shared_ptr<CWallet> const wallet = GetWalletForJSONRPCRequest(main_request);
+    CWallet* const pwallet = wallet.get();
+    if (!EnsureWalletIsAvailable(pwallet, main_request.fHelp)) {
+        return NullUniValue;
+    }
+
+            RPCHelpMan{"importdescriptors",
+                "\nImport descriptors. This will trigger a rescan of the blockchain based on the earliest timestamp of all descriptors being imported. Requires a new wallet backup.\n"
+            "\nNote: This call can take over an hour to complete if using an early timestamp; during that time, other rpc calls\n"
+            "may report that the imported keys, addresses or scripts exist but related transactions are still missing.\n",
+                {
+                    {"requests", RPCArg::Type::ARR, RPCArg::Optional::NO, "Data to be imported",
+                        {
+                            {"", RPCArg::Type::OBJ, RPCArg::Optional::OMITTED, "",
+                                {
+                                    {"desc", RPCArg::Type::STR, RPCArg::Optional::NO, "Descriptor to import."},
+                                    {"active", RPCArg::Type::BOOL, /* default */ "false", "Set this descriptor to be the active descriptor for the corresponding output type/externality"},
+                                    {"range", RPCArg::Type::RANGE, RPCArg::Optional::OMITTED, "If a ranged descriptor is used, this specifies the end or the range (in the form [begin,end]) to import"},
+                                    {"next_index", RPCArg::Type::NUM, RPCArg::Optional::OMITTED, "If a ranged descriptor is set to active, this specifies the next index to generate addresses from"},
+                                    {"timestamp", RPCArg::Type::NUM, RPCArg::Optional::NO, "Time from which to start rescanning the blockchain for this descriptor, in " + UNIX_EPOCH_TIME + "\n"
+        "                                                              Use the string \"now\" to substitute the current synced blockchain time.\n"
+        "                                                              \"now\" can be specified to bypass scanning, for outputs which are known to never have been used, and\n"
+        "                                                              0 can be specified to scan the entire blockchain. Blocks up to 2 hours before the earliest timestamp\n"
+        "                                                              of all descriptors being imported will be scanned.",
+                                        /* oneline_description */ "", {"timestamp | \"now\"", "integer / string"}
+                                    },
+                                    {"internal", RPCArg::Type::BOOL, /* default */ "false", "Whether matching outputs should be treated as not incoming payments (e.g. change)"},
+                                    {"label", RPCArg::Type::STR, /* default */ "''", "Label to assign to the address, only allowed with internal=false"},
+                                },
+                            },
+                        },
+                        "\"requests\""},
+                },
+                RPCResult{
+                    RPCResult::Type::ARR, "", "Response is an array with the same size as the input that has the execution result",
+                    {
+                        {RPCResult::Type::OBJ, "", "",
+                        {
+                            {RPCResult::Type::BOOL, "success", ""},
+                            {RPCResult::Type::ARR, "warnings", /* optional */ true, "",
+                            {
+                                {RPCResult::Type::STR, "", ""},
+                            }},
+                            {RPCResult::Type::OBJ, "error", /* optional */ true, "",
+                            {
+                                {RPCResult::Type::ELISION, "", "JSONRPC error"},
+                            }},
+                        }},
+                    }
+                },
+                RPCExamples{
+                    HelpExampleCli("importdescriptors", "'[{ \"desc\": \"<my descriptor>\", \"timestamp\":1455191478, \"internal\": true }, "
+                                          "{ \"desc\": \"<my desccriptor 2>\", \"label\": \"example 2\", \"timestamp\": 1455191480 }]'") +
+                    HelpExampleCli("importdescriptors", "'[{ \"desc\": \"<my descriptor>\", \"timestamp\":1455191478, \"active\": true, \"range\": [0,100], \"label\": \"<my bech32 wallet>\" }]'")
+                },
+            }.Check(main_request);
+
+    //  Make sure wallet is a descriptor wallet
+    if (!pwallet->IsWalletFlagSet(WALLET_FLAG_DESCRIPTORS)) {
+        throw JSONRPCError(RPC_WALLET_ERROR, "importdescriptors is not available for non-descriptor wallets");
+    }
+
+    RPCTypeCheck(main_request.params, {UniValue::VARR, UniValue::VOBJ});
+
+    WalletRescanReserver reserver(*pwallet);
+    if (!reserver.reserve()) {
+        throw JSONRPCError(RPC_WALLET_ERROR, "Wallet is currently rescanning. Abort existing rescan or wait.");
+    }
+
+    const UniValue& requests = main_request.params[0];
+    const int64_t minimum_timestamp = 1;
+    int64_t now = 0;
+    int64_t lowest_timestamp = 0;
+    bool rescan = false;
+    UniValue response(UniValue::VARR);
+    {
+        auto locked_chain = pwallet->chain().lock();
+        LOCK(pwallet->cs_wallet);
+        EnsureWalletIsUnlocked(pwallet);
+
+        CHECK_NONFATAL(pwallet->chain().findBlock(pwallet->GetLastBlockHash(), FoundBlock().time(lowest_timestamp).mtpTime(now)));
+
+        // Get all timestamps and extract the lowest timestamp
+        for (const UniValue& request : requests.getValues()) {
+            // This throws an error if "timestamp" doesn't exist
+            const int64_t timestamp = std::max(GetImportTimestamp(request, now), minimum_timestamp);
+            const UniValue result = ProcessDescriptorImport(pwallet, request, timestamp);
+            response.push_back(result);
+
+            if (lowest_timestamp > timestamp ) {
+                lowest_timestamp = timestamp;
+            }
+
+            // If we know the chain tip, and at least one request was successful then allow rescan
+            if (!rescan && result["success"].get_bool()) {
+                rescan = true;
+            }
+        }
+        pwallet->ConnectScriptPubKeyManNotifiers();
+    }
+
+    // Rescan the blockchain using the lowest timestamp
+    if (rescan) {
+        int64_t scanned_time = pwallet->RescanFromTime(lowest_timestamp, reserver, true /* update */);
+        {
+            auto locked_chain = pwallet->chain().lock();
+            LOCK(pwallet->cs_wallet);
+            pwallet->ReacceptWalletTransactions();
+        }
+
+        if (pwallet->IsAbortingRescan()) {
+            throw JSONRPCError(RPC_MISC_ERROR, "Rescan aborted by user.");
+        }
+
+        if (scanned_time > lowest_timestamp) {
+            std::vector<UniValue> results = response.getValues();
+            response.clear();
+            response.setArray();
+
+            // Compose the response
+            for (unsigned int i = 0; i < requests.size(); ++i) {
+                const UniValue& request = requests.getValues().at(i);
+
+                // If the descriptor timestamp is within the successfully scanned
+                // range, or if the import result already has an error set, let
+                // the result stand unmodified. Otherwise replace the result
+                // with an error message.
+                if (scanned_time <= GetImportTimestamp(request, now) || results.at(i).exists("error")) {
+                    response.push_back(results.at(i));
+                } else {
+                    UniValue result = UniValue(UniValue::VOBJ);
+                    result.pushKV("success", UniValue(false));
+                    result.pushKV(
+                        "error",
+                        JSONRPCError(
+                            RPC_MISC_ERROR,
+                            strprintf("Rescan failed for descriptor with timestamp %d. There was an error reading a "
+                                      "block from time %d, which is after or within %d seconds of key creation, and "
+                                      "could contain transactions pertaining to the desc. As a result, transactions "
+                                      "and coins using this desc may not appear in the wallet. This error could be "
+                                      "caused by pruning or data corruption (see bitcoind log for details) and could "
+                                      "be dealt with by downloading and rescanning the relevant blocks (see -reindex "
+                                      "and -rescan options).",
+                                GetImportTimestamp(request, now), scanned_time - TIMESTAMP_WINDOW - 1, TIMESTAMP_WINDOW)));
+                    response.push_back(std::move(result));
+                }
+            }
+        }
+    }
+
+    return response;
+}