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Stable release v32.1bitcoin/bitcoin · f0de87f04062 ↗3,020 source files · 47.5 MB stored on the server440 file guides

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bitcoin / bitcoinstable

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bitcoin / src / script / signingprovider.cpp

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501
502std::optional<std::vector<std::tuple<int, std::vector<unsigned char>, int>>> InferTaprootTree(const TaprootSpendData& spenddata, const XOnlyPubKey& output)
503{
504    // Verify that the output matches the assumed Merkle root and internal key.
505    auto tweak = spenddata.internal_key.CreateTapTweak(spenddata.merkle_root.IsNull() ? nullptr : &spenddata.merkle_root);
506    if (!tweak || tweak->first != output) return std::nullopt;
507    // If the Merkle root is 0, the tree is empty, and we're done.
508    std::vector<std::tuple<int, std::vector<unsigned char>, int>> ret;
509    if (spenddata.merkle_root.IsNull()) return ret;
510
511    /** Data structure to represent the nodes of the tree we're going to build. */
512    struct TreeNode {
513        /** Hash of this node, if known; 0 otherwise. */
514        uint256 hash;
515        /** The left and right subtrees (note that their order is irrelevant). */
516        std::unique_ptr<TreeNode> sub[2];
517        /** If this is known to be a leaf node, a pointer to the (script, leaf_ver) pair.
518         *  nullptr otherwise. */
519        const std::pair<std::vector<unsigned char>, int>* leaf = nullptr;
520        /** Whether or not this node has been explored (is known to be a leaf, or known to have children). */
521        bool explored = false;
522        /** Whether or not this node is an inner node (unknown until explored = true). */
523        bool inner;
524        /** Whether or not we have produced output for this subtree. */
525        bool done = false;
526    };
527
528    // Build tree from the provided branches.
529    TreeNode root;
530    root.hash = spenddata.merkle_root;
531    for (const auto& [key, control_blocks] : spenddata.scripts) {
532        const auto& [script, leaf_ver] = key;
533        for (const auto& control : control_blocks) {
534            // Skip script records with nonsensical leaf version.
535            if (leaf_ver < 0 || leaf_ver >= 0x100 || leaf_ver & 1) continue;
536            // Skip script records with invalid control block sizes.
537            if (control.size() < TAPROOT_CONTROL_BASE_SIZE || control.size() > TAPROOT_CONTROL_MAX_SIZE ||
538                ((control.size() - TAPROOT_CONTROL_BASE_SIZE) % TAPROOT_CONTROL_NODE_SIZE) != 0) continue;
539            // Skip script records that don't match the control block.
540            if ((control[0] & TAPROOT_LEAF_MASK) != leaf_ver) continue;
541            // Skip script records that don't match the provided Merkle root.
542            const uint256 leaf_hash = ComputeTapleafHash(leaf_ver, script);
543            const uint256 merkle_root = ComputeTaprootMerkleRoot(control, leaf_hash);
544            if (merkle_root != spenddata.merkle_root) continue;
545
546            TreeNode* node = &root;
547            size_t levels = (control.size() - TAPROOT_CONTROL_BASE_SIZE) / TAPROOT_CONTROL_NODE_SIZE;
548            for (size_t depth = 0; depth < levels; ++depth) {
549                // Can't descend into a node which we already know is a leaf.
550                if (node->explored && !node->inner) return std::nullopt;
551
552                // Extract partner hash from Merkle branch in control block.
553                uint256 hash;
554                std::copy(control.begin() + TAPROOT_CONTROL_BASE_SIZE + (levels - 1 - depth) * TAPROOT_CONTROL_NODE_SIZE,
555                          control.begin() + TAPROOT_CONTROL_BASE_SIZE + (levels - depth) * TAPROOT_CONTROL_NODE_SIZE,
556                          hash.begin());
557
558                if (node->sub[0]) {
559                    // Descend into the existing left or right branch.
560                    bool desc = false;
561                    for (int i = 0; i < 2; ++i) {
562                        if (node->sub[i]->hash == hash || (node->sub[i]->hash.IsNull() && node->sub[1-i]->hash != hash)) {
563                            node->sub[i]->hash = hash;
564                            node = &*node->sub[1-i];
565                            desc = true;
566                            break;
567                        }
568                    }
569                    if (!desc) return std::nullopt; // This probably requires a hash collision to hit.
570                } else {
571                    // We're in an unexplored node. Create subtrees and descend.
572                    node->explored = true;
573                    node->inner = true;
574                    node->sub[0] = std::make_unique<TreeNode>();
575                    node->sub[1] = std::make_unique<TreeNode>();
576                    node->sub[1]->hash = hash;
577                    node = &*node->sub[0];
578                }
579            }
580            // Cannot turn a known inner node into a leaf.
581            if (node->sub[0]) return std::nullopt;
582            node->explored = true;
583            node->inner = false;
584            node->leaf = &key;
585            node->hash = leaf_hash;
586        }
587    }
588
589    // Recursive processing to turn the tree into flattened output. Use an explicit stack here to avoid
590    // overflowing the call stack (the tree may be 128 levels deep).
591    std::vector<TreeNode*> stack{&root};
592    while (!stack.empty()) {
593        TreeNode& node = *stack.back();
594        if (!node.explored) {
595            // Unexplored node, which means the tree is incomplete.
596            return std::nullopt;
597        } else if (!node.inner) {
598            // Leaf node; produce output.
599            ret.emplace_back(stack.size() - 1, node.leaf->first, node.leaf->second);
600            node.done = true;
601            stack.pop_back();
602        } else if (node.sub[0]->done && !node.sub[1]->done && !node.sub[1]->explored && !node.sub[1]->hash.IsNull() &&
603                   ComputeTapbranchHash(node.sub[1]->hash, node.sub[1]->hash) == node.hash) {
604            // Whenever there are nodes with two identical subtrees under it, we run into a problem:
605            // the control blocks for the leaves underneath those will be identical as well, and thus
606            // they will all be matched to the same path in the tree. The result is that at the location
607            // where the duplicate occurred, the left child will contain a normal tree that can be explored
608            // and processed, but the right one will remain unexplored.
609            //
610            // This situation can be detected, by encountering an inner node with unexplored right subtree
611            // with known hash, and H_TapBranch(hash, hash) is equal to the parent node (this node)'s hash.
612            //
613            // To deal with this, simply process the left tree a second time (set its done flag to false;
614            // noting that the done flag of its children have already been set to false after processing
615            // those). To avoid ending up in an infinite loop, set the done flag of the right (unexplored)
616            // subtree to true.
617            node.sub[0]->done = false;
618            node.sub[1]->done = true;
619        } else if (node.sub[0]->done && node.sub[1]->done) {
620            // An internal node which we're finished with.
621            node.sub[0]->done = false;
622            node.sub[1]->done = false;
623            node.done = true;
624            stack.pop_back();
625        } else if (!node.sub[0]->done) {
626            // An internal node whose left branch hasn't been processed yet. Do so first.
627            stack.push_back(&*node.sub[0]);
628        } else if (!node.sub[1]->done) {
629            // An internal node whose right branch hasn't been processed yet. Do so first.
630            stack.push_back(&*node.sub[1]);
631        }
632    }
633
634    return ret;
635}
636
637std::vector<std::tuple<uint8_t, uint8_t, std::vector<unsigned char>>> TaprootBuilder::GetTreeTuples() const
638{
639    assert(IsComplete());
640    std::vector<std::tuple<uint8_t, uint8_t, std::vector<unsigned char>>> tuples;
641    if (m_branch.size()) {
642        const auto& leaves = m_branch[0]->leaves;
643        for (const auto& leaf : leaves) {
644            assert(leaf.merkle_branch.size() <= TAPROOT_CONTROL_MAX_NODE_COUNT);
645            uint8_t depth = (uint8_t)leaf.merkle_branch.size();
646            uint8_t leaf_ver = (uint8_t)leaf.leaf_version;
647            tuples.emplace_back(depth, leaf_ver, leaf.script);
648        }
649    }
650    return tuples;
651}
652

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440 guided files · 2,580 pending. Guides cover key sections, not every line.

cmake/bitcoin-build-config.h.in src/consensus/amount.h src/consensus/consensus.h src/primitives/block.h src/primitives/transaction.h src/crypto/sha256.h src/util/moneystr.h src/clientversion.h src/uint256.h src/script/script.h src/policy/policy.h CMakeLists.txt README.md COPYING src/consensus/tx_check.cpp src/consensus/tx_verify.cpp src/consensus/merkle.cpp src/pow.cpp src/validation.cpp src/script/interpreter.cpp src/script/solver.cpp src/script/sign.cpp src/key_io.cpp src/net.cpp src/net_processing.cpp src/netaddress.cpp src/protocol.h src/wallet/wallet.cpp src/wallet/spend.cpp

← Previous 250 linesCode page 3

src/wallet/receive.cpp

src/wallet/coinselection.cpp

src/consensus/validation.h

src/primitives/transaction.cpp

src/script/descriptor.cpp

src/bitcoin-cli.cpp

src/rpc/blockchain.cpp

src/rpc/rawtransaction.cpp

src/init.cpp

src/crypto/sha256.cpp

src/consensus/merkle.h

src/consensus/tx_check.h

src/consensus/tx_verify.h

src/policy/feerate.h

src/policy/feerate.cpp

src/primitives/transaction_identifier.h

src/chainparamsbase.h

src/chainparamsbase.cpp

src/util/moneystr.cpp

src/crypto/ripemd160.h

src/crypto/sha1.h

src/crypto/sha512.h

src/crypto/hmac_sha256.h

src/crypto/hmac_sha512.h

src/crypto/hmac_sha256.cpp

src/crypto/hmac_sha512.cpp

src/crypto/hkdf_sha256_32.h

src/crypto/hkdf_sha256_32.cpp

src/support/cleanse.h

src/support/cleanse.cpp

src/crypto/siphash.cpp

src/crypto/muhash.h

src/crypto/chacha20.h

src/crypto/poly1305.h

src/crypto/chacha20poly1305.h

src/crypto/chacha20poly1305.cpp

src/util/chaintype.cpp

src/util/obfuscation.h

src/util/byte_units.h

src/util/overflow.h

src/blockencodings.cpp

src/net_permissions.cpp

src/policy/packages.cpp

src/policy/rbf.cpp

src/policy/truc_policy.cpp

src/policy/ephemeral_policy.cpp

src/policy/settings.cpp

src/policy/policy.cpp

src/node/transaction.cpp

src/node/coin.cpp

src/rpc/client.cpp

src/rpc/external_signer.cpp

src/rpc/request.cpp

src/rpc/server_util.cpp

src/rpc/fees.cpp

src/rpc/output_script.cpp

src/rpc/rawtransaction_util.cpp

src/rpc/rawtransaction_util.h

src/rpc/register.h

src/rpc/request.h

src/rpc/server_util.h

src/rpc/protocol.h

src/rpc/server.h

src/rpc/signmessage.cpp

src/rpc/txoutproof.cpp

src/rpc/util.cpp

src/rpc/util.h

src/wallet/rpc/addresses.cpp

src/wallet/rpc/backup.cpp

src/wallet/rpc/coins.cpp

src/wallet/rpc/encrypt.cpp

src/wallet/rpc/signmessage.cpp

src/wallet/rpc/util.cpp

src/wallet/rpc/util.h

src/wallet/coincontrol.cpp

src/wallet/coincontrol.h

src/wallet/context.cpp

src/wallet/context.h

src/wallet/crypter.cpp

src/wallet/crypter.h

src/wallet/db.cpp

src/wallet/export.cpp

src/wallet/external_signer_scriptpubkeyman.cpp

src/wallet/rpc/spend.cpp

src/wallet/rpc/transactions.cpp

src/wallet/rpc/wallet.cpp

src/wallet/feebumper.cpp

src/wallet/feebumper.h

src/index/base.h

src/index/base.cpp

src/index/txindex.h

src/index/txindex.cpp

src/index/txindex_key.h

src/index/txospenderindex.h

src/index/txospenderindex.cpp

src/index/blockfilterindex.h

src/index/blockfilterindex.cpp

src/index/coinstatsindex.h

src/index/coinstatsindex.cpp

src/index/db_key.h

src/index/disktxpos.h

src/kernel/chain.cpp

src/kernel/chain.h

src/kernel/checks.cpp

src/kernel/checks.h

src/kernel/context.cpp

src/kernel/context.h

src/kernel/cs_main.cpp

src/kernel/cs_main.h

src/kernel/disconnected_transactions.cpp

src/kernel/disconnected_transactions.h

src/kernel/mempool_removal_reason.cpp

src/kernel/mempool_removal_reason.h

src/kernel/coinstats.cpp

src/kernel/coinstats.h

src/kernel/chainparams.cpp

src/kernel/chainparams.h

src/wallet/sqlite.cpp

src/wallet/sqlite.h

src/wallet/transaction.cpp

src/wallet/transaction.h

src/wallet/dump.cpp

src/wallet/dump.h

src/wallet/init.cpp

src/wallet/walletutil.cpp

src/wallet/walletutil.h

src/wallet/wallettool.cpp

src/wallet/wallettool.h

src/wallet/export.h

src/wallet/migrate.cpp

src/wallet/migrate.h

src/wallet/db.h

src/wallet/walletdb.cpp

src/wallet/interfaces.cpp

src/wallet/scriptpubkeyman.cpp

src/wallet/scriptpubkeyman.h

src/kernel/bitcoinkernel.cpp

src/kernel/bitcoinkernel.h

src/kernel/bitcoinkernel_wrapper.h

src/node/chainstate.cpp

src/node/chainstate.h

src/node/blockstorage.cpp

src/node/blockstorage.h

src/node/mempool_persist.cpp

src/node/mempool_persist.h

src/node/utxo_snapshot.cpp

src/node/utxo_snapshot.h

src/node/kernel_notifications.cpp

src/node/kernel_notifications.h

src/node/blockmanager_args.cpp

src/kernel/blockmanager_opts.h

src/util/expected.cpp

src/policy/settings.h

src/util/types.h

src/kernel/messagestartchars.h

src/kernel/warning.h

src/util/exception.h

src/common/license_info.h

src/node/coins_view_args.h

src/node/database_args.h

src/util/batchpriority.h

src/util/ui_change_type.h

src/node/coins_view_args.cpp

src/node/peerman_args.h

src/util/serfloat.h

src/node/blockmanager_args.h

src/node/database_args.cpp

src/util/overloaded.h

src/interfaces/types.h

src/node/chainstatemanager_args.h

src/node/minisketchwrapper.h

src/util/macros.h

src/util/syserror.h

src/common/run_command.h

src/util/bytevectorhash.cpp

src/node/mempool_persist_args.cpp

src/util/exec.h

src/util/rbf.h

src/crypto/hex_base.h

src/node/mempool_persist_args.h

src/interfaces/echo.h

src/util/any.h

src/util/batchpriority.cpp

src/util/threadnames.h

src/node/coin.h

src/node/mempool_args.h

src/util/asmap.h

src/util/bytevectorhash.h

src/node/context.cpp

src/util/insert.h

src/util/readwritefile.h

src/node/peerman_args.cpp

src/node/interface_ui.cpp

src/interfaces/handler.h

src/node/mining_args.h

src/util/hasher.cpp

src/common/init.h

src/kernel/mempool_limits.h

src/common/system.h

src/crypto/sha3.h

src/util/threadinterrupt.cpp

src/node/protocol_version.h

src/util/exception.cpp

src/common/messages.h

src/node/connection_types.cpp

src/util/bip32.h

src/common/license_info.cpp

src/util/stdmutex.h

src/common/run_command.cpp

src/util/check.cpp

src/util/golombrice.h

src/node/types.h

src/node/timeoffsets.h

src/util/readwritefile.cpp

src/util/fastrange.h

src/util/signalinterrupt.h

src/util/task_runner.h

src/util/syserror.cpp

src/common/interfaces.cpp

src/common/types.h

src/util/threadinterrupt.h

src/kernel/chainstatemanager_opts.h

src/node/psbt.h

src/policy/ephemeral_policy.h

src/util/trace.h

src/common/url.cpp

src/kernel/mempool_options.h

src/util/serfloat.cpp

src/kernel/notifications_interface.h

src/node/timeoffsets.cpp

src/node/warnings.cpp

src/util/hash_type.h

src/crypto/hex_base.cpp

src/node/eviction.h

src/util/tokenbucket.h

src/crypto/aes.h

src/common/pcp.h

src/util/feefrac.cpp

src/node/transaction.h

src/util/threadnames.cpp

src/common/signmessage.h

src/util/exec.cpp

src/util/signalinterrupt.cpp

src/clientversion.cpp

src/common/signmessage.cpp

src/compat/assumptions.h

src/compat/byteswap.h

src/deploymentinfo.cpp

src/deploymentinfo.h

src/deploymentstatus.cpp

src/deploymentstatus.h

src/dummywallet.cpp

src/external_signer.h

src/init/bitcoin-gui.cpp

src/init/bitcoin-node.cpp

src/init/bitcoin-qt.cpp

src/init/bitcoin-wallet.cpp

src/init/bitcoind.cpp

src/init/common.h

src/interfaces/init.h

src/interfaces/ipc.h

src/key_io.h

src/logging/categories.h

src/logging/timer.h

src/mapport.h

src/musig.h

src/net_permissions.h

src/netgroup.h

src/netmessagemaker.h

src/node/chainstatemanager_args.cpp

src/node/connection_types.h

src/node/context.h

src/node/interface_ui.h

src/node/mempool_args.cpp

src/node/mining_args.cpp

src/node/minisketchwrapper.cpp

src/node/txreconciliation.h

src/policy/fees/estimator_args.cpp

src/policy/fees/estimator_args.h

src/policy/fees/estimator_man.cpp

src/policy/fees/estimator_man.h

src/policy/packages.h

src/policy/rbf.h

src/policy/truc_policy.h

src/pow.h

src/primitives/block.cpp

src/randomenv.h

src/rest.h

src/script/keyorigin.h

src/script/parsing.cpp

src/script/parsing.h

src/script/script_error.h

src/script/sigcache.cpp

src/script/sigcache.h

src/script/solver.h

src/script/verify_flags.h

src/semaphore_grant.h

src/signet.h

src/span.h

src/support/allocators/secure.h

src/support/allocators/zeroafterfree.h

src/util/tokenpipe.cpp

src/util/translation.h

src/util/vector.h

src/versionbits.h

src/versionbits_impl.h

src/wallet/external_signer_scriptpubkeyman.h

src/wallet/fees.h

src/wallet/load.h

src/wallet/receive.h

src/wallet/rpc/wallet.h

src/wallet/types.h

src/walletinitinterface.h

src/zmq/zmqabstractnotifier.cpp

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