Merge bitcoin/bitcoin#26177: refactor / kernel: Move non-gArgs chainparams functionality to kernel

b3e78dc91d01e364b77aacd9fb9a2f88688ab8a6 refactor: Don't use global chainparams in chainstatemanager method (TheCharlatan)
382b692a503355df7347efd9c128aff465b5583e Split non/kernel chainparams (Carl Dong)
edabbc78a3bc272b2b802e1dbab73d6ed8e31e96 Add factory functions for Main/Test/Sig/Reg chainparams (Carl Dong)
d938098398814f37fed9b018b44716179cfa4b03 Remove UpdateVersionBitsParameters (Carl Dong)
84b85786f0f5cb23cc257a4464ae345e1d372313 Decouple RegTestChainParams from ArgsManager (Carl Dong)
76cd4e7c96242398172989609f1b9a8843c404b4 Decouple SigNetChainParams from ArgsManager (Carl Dong)

Pull request description:

  This pull request is part of the `libbitcoinkernel` project https://github.com/bitcoin/bitcoin/issues/24303 https://github.com/bitcoin/bitcoin/projects/18 and more specifically its "Step 2: Decouple most non-consensus code from libbitcoinkernel". dongcarl is the original author of this patchset, these commits were taken from https://github.com/dongcarl/bitcoin/tree/2022-03-libbitcoinkernel-chainparams-args-only.

  #### Context

  The bitcoin kernel library currently relies on code containing user configurations through the `ArgsManager`. This is not optimal, since as a stand-alone library it should not rely on bitcoind's argument parsing logic. Instead, its interfaces should accept control and options structs that control the kernel library's desired configuration.

  Similar work towards decoupling the `ArgsManager` from the kernel has been done in
  https://github.com/bitcoin/bitcoin/pull/25290, https://github.com/bitcoin/bitcoin/pull/25487, https://github.com/bitcoin/bitcoin/pull/25527 and https://github.com/bitcoin/bitcoin/pull/25862.

  #### Changes

  By moving the `CChainParams` class definition into the kernel and giving it new factory functions `CChainParams::{RegTest,SigNet,Main,TestNet}`it can be constructed without an `ArgsManager` reference, unlike the current factory function `CreateChainParams`.

  The first few commits remove uses of `ArgsManager` within `CChainParams`. Then the `CChainParams` definition is moved to a new file in the `kernel/` subdirectory.

ACKs for top commit:
  MarcoFalke:
    re-ACK b3e78dc91d01e364b77aacd9fb9a2f88688ab8a6 🛁
  ryanofsky:
    Code review ACK b3e78dc91d01e364b77aacd9fb9a2f88688ab8a6. Only changes since last review were recent review suggestions.
  ajtowns:
    ACK b3e78dc91d01e364b77aacd9fb9a2f88688ab8a6

Tree-SHA512: 3835aca1d3e3c75cc3303dd584bab3a77e58f6c678724a5e359fe4b0e17e0763a00931ee6191f516b9fde50496f59cc691f0709c0254206db3863bbf7ab2cacd

2 files changed, 719 insertions, 0 deletions

diff --git a/src/kernel/chainparams.cpp b/src/kernel/chainparams.cpp
new file mode 100644
index 0000000000..e0c4aff6f4
--- /dev/null
+++ b/src/kernel/chainparams.cpp
@@ -0,0 +1,532 @@
+// Copyright (c) 2010 Satoshi Nakamoto
+// Copyright (c) 2009-2021 The Bitcoin Core developers
+// Distributed under the MIT software license, see the accompanying
+// file COPYING or http://www.opensource.org/licenses/mit-license.php.
+
+#include <kernel/chainparams.h>
+
+#include <chainparamsseeds.h>
+#include <consensus/amount.h>
+#include <consensus/merkle.h>
+#include <consensus/params.h>
+#include <hash.h>
+#include <chainparamsbase.h>
+#include <logging.h>
+#include <primitives/block.h>
+#include <primitives/transaction.h>
+#include <script/interpreter.h>
+#include <script/script.h>
+#include <uint256.h>
+#include <util/strencodings.h>
+
+#include <algorithm>
+#include <cassert>
+#include <cstdint>
+#include <cstring>
+#include <type_traits>
+
+static CBlock CreateGenesisBlock(const char* pszTimestamp, const CScript& genesisOutputScript, uint32_t nTime, uint32_t nNonce, uint32_t nBits, int32_t nVersion, const CAmount& genesisReward)
+{
+    CMutableTransaction txNew;
+    txNew.nVersion = 1;
+    txNew.vin.resize(1);
+    txNew.vout.resize(1);
+    txNew.vin[0].scriptSig = CScript() << 486604799 << CScriptNum(4) << std::vector<unsigned char>((const unsigned char*)pszTimestamp, (const unsigned char*)pszTimestamp + strlen(pszTimestamp));
+    txNew.vout[0].nValue = genesisReward;
+    txNew.vout[0].scriptPubKey = genesisOutputScript;
+
+    CBlock genesis;
+    genesis.nTime    = nTime;
+    genesis.nBits    = nBits;
+    genesis.nNonce   = nNonce;
+    genesis.nVersion = nVersion;
+    genesis.vtx.push_back(MakeTransactionRef(std::move(txNew)));
+    genesis.hashPrevBlock.SetNull();
+    genesis.hashMerkleRoot = BlockMerkleRoot(genesis);
+    return genesis;
+}
+
+/**
+ * Build the genesis block. Note that the output of its generation
+ * transaction cannot be spent since it did not originally exist in the
+ * database.
+ *
+ * CBlock(hash=000000000019d6, ver=1, hashPrevBlock=00000000000000, hashMerkleRoot=4a5e1e, nTime=1231006505, nBits=1d00ffff, nNonce=2083236893, vtx=1)
+ *   CTransaction(hash=4a5e1e, ver=1, vin.size=1, vout.size=1, nLockTime=0)
+ *     CTxIn(COutPoint(000000, -1), coinbase 04ffff001d0104455468652054696d65732030332f4a616e2f32303039204368616e63656c6c6f72206f6e206272696e6b206f66207365636f6e64206261696c6f757420666f722062616e6b73)
+ *     CTxOut(nValue=50.00000000, scriptPubKey=0x5F1DF16B2B704C8A578D0B)
+ *   vMerkleTree: 4a5e1e
+ */
+static CBlock CreateGenesisBlock(uint32_t nTime, uint32_t nNonce, uint32_t nBits, int32_t nVersion, const CAmount& genesisReward)
+{
+    const char* pszTimestamp = "The Times 03/Jan/2009 Chancellor on brink of second bailout for banks";
+    const CScript genesisOutputScript = CScript() << ParseHex("04678afdb0fe5548271967f1a67130b7105cd6a828e03909a67962e0ea1f61deb649f6bc3f4cef38c4f35504e51ec112de5c384df7ba0b8d578a4c702b6bf11d5f") << OP_CHECKSIG;
+    return CreateGenesisBlock(pszTimestamp, genesisOutputScript, nTime, nNonce, nBits, nVersion, genesisReward);
+}
+
+/**
+ * Main network on which people trade goods and services.
+ */
+class CMainParams : public CChainParams {
+public:
+    CMainParams() {
+        strNetworkID = CBaseChainParams::MAIN;
+        consensus.signet_blocks = false;
+        consensus.signet_challenge.clear();
+        consensus.nSubsidyHalvingInterval = 210000;
+        consensus.script_flag_exceptions.emplace( // BIP16 exception
+            uint256S("0x00000000000002dc756eebf4f49723ed8d30cc28a5f108eb94b1ba88ac4f9c22"), SCRIPT_VERIFY_NONE);
+        consensus.script_flag_exceptions.emplace( // Taproot exception
+            uint256S("0x0000000000000000000f14c35b2d841e986ab5441de8c585d5ffe55ea1e395ad"), SCRIPT_VERIFY_P2SH | SCRIPT_VERIFY_WITNESS);
+        consensus.BIP34Height = 227931;
+        consensus.BIP34Hash = uint256S("0x000000000000024b89b42a942fe0d9fea3bb44ab7bd1b19115dd6a759c0808b8");
+        consensus.BIP65Height = 388381; // 000000000000000004c2b624ed5d7756c508d90fd0da2c7c679febfa6c4735f0
+        consensus.BIP66Height = 363725; // 00000000000000000379eaa19dce8c9b722d46ae6a57c2f1a988119488b50931
+        consensus.CSVHeight = 419328; // 000000000000000004a1b34462cb8aeebd5799177f7a29cf28f2d1961716b5b5
+        consensus.SegwitHeight = 481824; // 0000000000000000001c8018d9cb3b742ef25114f27563e3fc4a1902167f9893
+        consensus.MinBIP9WarningHeight = 483840; // segwit activation height + miner confirmation window
+        consensus.powLimit = uint256S("00000000ffffffffffffffffffffffffffffffffffffffffffffffffffffffff");
+        consensus.nPowTargetTimespan = 14 * 24 * 60 * 60; // two weeks
+        consensus.nPowTargetSpacing = 10 * 60;
+        consensus.fPowAllowMinDifficultyBlocks = false;
+        consensus.fPowNoRetargeting = false;
+        consensus.nRuleChangeActivationThreshold = 1815; // 90% of 2016
+        consensus.nMinerConfirmationWindow = 2016; // nPowTargetTimespan / nPowTargetSpacing
+        consensus.vDeployments[Consensus::DEPLOYMENT_TESTDUMMY].bit = 28;
+        consensus.vDeployments[Consensus::DEPLOYMENT_TESTDUMMY].nStartTime = Consensus::BIP9Deployment::NEVER_ACTIVE;
+        consensus.vDeployments[Consensus::DEPLOYMENT_TESTDUMMY].nTimeout = Consensus::BIP9Deployment::NO_TIMEOUT;
+        consensus.vDeployments[Consensus::DEPLOYMENT_TESTDUMMY].min_activation_height = 0; // No activation delay
+
+        // Deployment of Taproot (BIPs 340-342)
+        consensus.vDeployments[Consensus::DEPLOYMENT_TAPROOT].bit = 2;
+        consensus.vDeployments[Consensus::DEPLOYMENT_TAPROOT].nStartTime = 1619222400; // April 24th, 2021
+        consensus.vDeployments[Consensus::DEPLOYMENT_TAPROOT].nTimeout = 1628640000; // August 11th, 2021
+        consensus.vDeployments[Consensus::DEPLOYMENT_TAPROOT].min_activation_height = 709632; // Approximately November 12th, 2021
+
+        consensus.nMinimumChainWork = uint256S("0x00000000000000000000000000000000000000003404ba0801921119f903495e");
+        consensus.defaultAssumeValid = uint256S("0x00000000000000000009c97098b5295f7e5f183ac811fb5d1534040adb93cabd"); // 751565
+
+        /**
+         * The message start string is designed to be unlikely to occur in normal data.
+         * The characters are rarely used upper ASCII, not valid as UTF-8, and produce
+         * a large 32-bit integer with any alignment.
+         */
+        pchMessageStart[0] = 0xf9;
+        pchMessageStart[1] = 0xbe;
+        pchMessageStart[2] = 0xb4;
+        pchMessageStart[3] = 0xd9;
+        nDefaultPort = 8333;
+        nPruneAfterHeight = 100000;
+        m_assumed_blockchain_size = 496;
+        m_assumed_chain_state_size = 6;
+
+        genesis = CreateGenesisBlock(1231006505, 2083236893, 0x1d00ffff, 1, 50 * COIN);
+        consensus.hashGenesisBlock = genesis.GetHash();
+        assert(consensus.hashGenesisBlock == uint256S("0x000000000019d6689c085ae165831e934ff763ae46a2a6c172b3f1b60a8ce26f"));
+        assert(genesis.hashMerkleRoot == uint256S("0x4a5e1e4baab89f3a32518a88c31bc87f618f76673e2cc77ab2127b7afdeda33b"));
+
+        // Note that of those which support the service bits prefix, most only support a subset of
+        // possible options.
+        // This is fine at runtime as we'll fall back to using them as an addrfetch if they don't support the
+        // service bits we want, but we should get them updated to support all service bits wanted by any
+        // release ASAP to avoid it where possible.
+        vSeeds.emplace_back("seed.bitcoin.sipa.be."); // Pieter Wuille, only supports x1, x5, x9, and xd
+        vSeeds.emplace_back("dnsseed.bluematt.me."); // Matt Corallo, only supports x9
+        vSeeds.emplace_back("dnsseed.bitcoin.dashjr.org."); // Luke Dashjr
+        vSeeds.emplace_back("seed.bitcoinstats.com."); // Christian Decker, supports x1 - xf
+        vSeeds.emplace_back("seed.bitcoin.jonasschnelli.ch."); // Jonas Schnelli, only supports x1, x5, x9, and xd
+        vSeeds.emplace_back("seed.btc.petertodd.org."); // Peter Todd, only supports x1, x5, x9, and xd
+        vSeeds.emplace_back("seed.bitcoin.sprovoost.nl."); // Sjors Provoost
+        vSeeds.emplace_back("dnsseed.emzy.de."); // Stephan Oeste
+        vSeeds.emplace_back("seed.bitcoin.wiz.biz."); // Jason Maurice
+
+        base58Prefixes[PUBKEY_ADDRESS] = std::vector<unsigned char>(1,0);
+        base58Prefixes[SCRIPT_ADDRESS] = std::vector<unsigned char>(1,5);
+        base58Prefixes[SECRET_KEY] =     std::vector<unsigned char>(1,128);
+        base58Prefixes[EXT_PUBLIC_KEY] = {0x04, 0x88, 0xB2, 0x1E};
+        base58Prefixes[EXT_SECRET_KEY] = {0x04, 0x88, 0xAD, 0xE4};
+
+        bech32_hrp = "bc";
+
+        vFixedSeeds = std::vector<uint8_t>(std::begin(chainparams_seed_main), std::end(chainparams_seed_main));
+
+        fDefaultConsistencyChecks = false;
+        fRequireStandard = true;
+        m_is_test_chain = false;
+        m_is_mockable_chain = false;
+
+        checkpointData = {
+            {
+                { 11111, uint256S("0x0000000069e244f73d78e8fd29ba2fd2ed618bd6fa2ee92559f542fdb26e7c1d")},
+                { 33333, uint256S("0x000000002dd5588a74784eaa7ab0507a18ad16a236e7b1ce69f00d7ddfb5d0a6")},
+                { 74000, uint256S("0x0000000000573993a3c9e41ce34471c079dcf5f52a0e824a81e7f953b8661a20")},
+                {105000, uint256S("0x00000000000291ce28027faea320c8d2b054b2e0fe44a773f3eefb151d6bdc97")},
+                {134444, uint256S("0x00000000000005b12ffd4cd315cd34ffd4a594f430ac814c91184a0d42d2b0fe")},
+                {168000, uint256S("0x000000000000099e61ea72015e79632f216fe6cb33d7899acb35b75c8303b763")},
+                {193000, uint256S("0x000000000000059f452a5f7340de6682a977387c17010ff6e6c3bd83ca8b1317")},
+                {210000, uint256S("0x000000000000048b95347e83192f69cf0366076336c639f9b7228e9ba171342e")},
+                {216116, uint256S("0x00000000000001b4f4b433e81ee46494af945cf96014816a4e2370f11b23df4e")},
+                {225430, uint256S("0x00000000000001c108384350f74090433e7fcf79a606b8e797f065b130575932")},
+                {250000, uint256S("0x000000000000003887df1f29024b06fc2200b55f8af8f35453d7be294df2d214")},
+                {279000, uint256S("0x0000000000000001ae8c72a0b0c301f67e3afca10e819efa9041e458e9bd7e40")},
+                {295000, uint256S("0x00000000000000004d9b4ef50f0f9d686fd69db2e03af35a100370c64632a983")},
+            }
+        };
+
+        m_assumeutxo_data = MapAssumeutxo{
+         // TODO to be specified in a future patch.
+        };
+
+        chainTxData = ChainTxData{
+            // Data from RPC: getchaintxstats 4096 00000000000000000009c97098b5295f7e5f183ac811fb5d1534040adb93cabd
+            .nTime    = 1661697692,
+            .nTxCount = 760120522,
+            .dTxRate  = 2.925802860942233,
+        };
+    }
+};
+
+/**
+ * Testnet (v3): public test network which is reset from time to time.
+ */
+class CTestNetParams : public CChainParams {
+public:
+    CTestNetParams() {
+        strNetworkID = CBaseChainParams::TESTNET;
+        consensus.signet_blocks = false;
+        consensus.signet_challenge.clear();
+        consensus.nSubsidyHalvingInterval = 210000;
+        consensus.script_flag_exceptions.emplace( // BIP16 exception
+            uint256S("0x00000000dd30457c001f4095d208cc1296b0eed002427aa599874af7a432b105"), SCRIPT_VERIFY_NONE);
+        consensus.BIP34Height = 21111;
+        consensus.BIP34Hash = uint256S("0x0000000023b3a96d3484e5abb3755c413e7d41500f8e2a5c3f0dd01299cd8ef8");
+        consensus.BIP65Height = 581885; // 00000000007f6655f22f98e72ed80d8b06dc761d5da09df0fa1dc4be4f861eb6
+        consensus.BIP66Height = 330776; // 000000002104c8c45e99a8853285a3b592602a3ccde2b832481da85e9e4ba182
+        consensus.CSVHeight = 770112; // 00000000025e930139bac5c6c31a403776da130831ab85be56578f3fa75369bb
+        consensus.SegwitHeight = 834624; // 00000000002b980fcd729daaa248fd9316a5200e9b367f4ff2c42453e84201ca
+        consensus.MinBIP9WarningHeight = 836640; // segwit activation height + miner confirmation window
+        consensus.powLimit = uint256S("00000000ffffffffffffffffffffffffffffffffffffffffffffffffffffffff");
+        consensus.nPowTargetTimespan = 14 * 24 * 60 * 60; // two weeks
+        consensus.nPowTargetSpacing = 10 * 60;
+        consensus.fPowAllowMinDifficultyBlocks = true;
+        consensus.fPowNoRetargeting = false;
+        consensus.nRuleChangeActivationThreshold = 1512; // 75% for testchains
+        consensus.nMinerConfirmationWindow = 2016; // nPowTargetTimespan / nPowTargetSpacing
+        consensus.vDeployments[Consensus::DEPLOYMENT_TESTDUMMY].bit = 28;
+        consensus.vDeployments[Consensus::DEPLOYMENT_TESTDUMMY].nStartTime = Consensus::BIP9Deployment::NEVER_ACTIVE;
+        consensus.vDeployments[Consensus::DEPLOYMENT_TESTDUMMY].nTimeout = Consensus::BIP9Deployment::NO_TIMEOUT;
+        consensus.vDeployments[Consensus::DEPLOYMENT_TESTDUMMY].min_activation_height = 0; // No activation delay
+
+        // Deployment of Taproot (BIPs 340-342)
+        consensus.vDeployments[Consensus::DEPLOYMENT_TAPROOT].bit = 2;
+        consensus.vDeployments[Consensus::DEPLOYMENT_TAPROOT].nStartTime = 1619222400; // April 24th, 2021
+        consensus.vDeployments[Consensus::DEPLOYMENT_TAPROOT].nTimeout = 1628640000; // August 11th, 2021
+        consensus.vDeployments[Consensus::DEPLOYMENT_TAPROOT].min_activation_height = 0; // No activation delay
+
+        consensus.nMinimumChainWork = uint256S("0x00000000000000000000000000000000000000000000076f6e7cbd0beade5d20");
+        consensus.defaultAssumeValid = uint256S("0x0000000000000004877fa2d36316398528de4f347df2f8a96f76613a298ce060"); // 2344474
+
+        pchMessageStart[0] = 0x0b;
+        pchMessageStart[1] = 0x11;
+        pchMessageStart[2] = 0x09;
+        pchMessageStart[3] = 0x07;
+        nDefaultPort = 18333;
+        nPruneAfterHeight = 1000;
+        m_assumed_blockchain_size = 42;
+        m_assumed_chain_state_size = 2;
+
+        genesis = CreateGenesisBlock(1296688602, 414098458, 0x1d00ffff, 1, 50 * COIN);
+        consensus.hashGenesisBlock = genesis.GetHash();
+        assert(consensus.hashGenesisBlock == uint256S("0x000000000933ea01ad0ee984209779baaec3ced90fa3f408719526f8d77f4943"));
+        assert(genesis.hashMerkleRoot == uint256S("0x4a5e1e4baab89f3a32518a88c31bc87f618f76673e2cc77ab2127b7afdeda33b"));
+
+        vFixedSeeds.clear();
+        vSeeds.clear();
+        // nodes with support for servicebits filtering should be at the top
+        vSeeds.emplace_back("testnet-seed.bitcoin.jonasschnelli.ch.");
+        vSeeds.emplace_back("seed.tbtc.petertodd.org.");
+        vSeeds.emplace_back("seed.testnet.bitcoin.sprovoost.nl.");
+        vSeeds.emplace_back("testnet-seed.bluematt.me."); // Just a static list of stable node(s), only supports x9
+
+        base58Prefixes[PUBKEY_ADDRESS] = std::vector<unsigned char>(1,111);
+        base58Prefixes[SCRIPT_ADDRESS] = std::vector<unsigned char>(1,196);
+        base58Prefixes[SECRET_KEY] =     std::vector<unsigned char>(1,239);
+        base58Prefixes[EXT_PUBLIC_KEY] = {0x04, 0x35, 0x87, 0xCF};
+        base58Prefixes[EXT_SECRET_KEY] = {0x04, 0x35, 0x83, 0x94};
+
+        bech32_hrp = "tb";
+
+        vFixedSeeds = std::vector<uint8_t>(std::begin(chainparams_seed_test), std::end(chainparams_seed_test));
+
+        fDefaultConsistencyChecks = false;
+        fRequireStandard = false;
+        m_is_test_chain = true;
+        m_is_mockable_chain = false;
+
+        checkpointData = {
+            {
+                {546, uint256S("000000002a936ca763904c3c35fce2f3556c559c0214345d31b1bcebf76acb70")},
+            }
+        };
+
+        m_assumeutxo_data = MapAssumeutxo{
+            // TODO to be specified in a future patch.
+        };
+
+        chainTxData = ChainTxData{
+            // Data from RPC: getchaintxstats 4096 0000000000000004877fa2d36316398528de4f347df2f8a96f76613a298ce060
+            .nTime    = 1661705221,
+            .nTxCount = 63531852,
+            .dTxRate  = 0.1079119341520164,
+        };
+    }
+};
+
+/**
+ * Signet: test network with an additional consensus parameter (see BIP325).
+ */
+class SigNetParams : public CChainParams {
+public:
+    explicit SigNetParams(const SigNetOptions& options)
+    {
+        std::vector<uint8_t> bin;
+        vSeeds.clear();
+
+        if (!options.challenge) {
+            bin = ParseHex("512103ad5e0edad18cb1f0fc0d28a3d4f1f3e445640337489abb10404f2d1e086be430210359ef5021964fe22d6f8e05b2463c9540ce96883fe3b278760f048f5189f2e6c452ae");
+            vSeeds.emplace_back("seed.signet.bitcoin.sprovoost.nl.");
+
+            // Hardcoded nodes can be removed once there are more DNS seeds
+            vSeeds.emplace_back("178.128.221.177");
+            vSeeds.emplace_back("v7ajjeirttkbnt32wpy3c6w3emwnfr3fkla7hpxcfokr3ysd3kqtzmqd.onion:38333");
+
+            consensus.nMinimumChainWork = uint256S("0x000000000000000000000000000000000000000000000000000001291fc22898");
+            consensus.defaultAssumeValid = uint256S("0x000000d1a0e224fa4679d2fb2187ba55431c284fa1b74cbc8cfda866fd4d2c09"); // 105495
+            m_assumed_blockchain_size = 1;
+            m_assumed_chain_state_size = 0;
+            chainTxData = ChainTxData{
+                // Data from RPC: getchaintxstats 4096 000000d1a0e224fa4679d2fb2187ba55431c284fa1b74cbc8cfda866fd4d2c09
+                .nTime    = 1661702566,
+                .nTxCount = 1903567,
+                .dTxRate  = 0.02336701143027275,
+            };
+        } else {
+            bin = *options.challenge;
+            consensus.nMinimumChainWork = uint256{};
+            consensus.defaultAssumeValid = uint256{};
+            m_assumed_blockchain_size = 0;
+            m_assumed_chain_state_size = 0;
+            chainTxData = ChainTxData{
+                0,
+                0,
+                0,
+            };
+            LogPrintf("Signet with challenge %s\n", HexStr(bin));
+        }
+
+        if (options.seeds) {
+            vSeeds = *options.seeds;
+        }
+
+        strNetworkID = CBaseChainParams::SIGNET;
+        consensus.signet_blocks = true;
+        consensus.signet_challenge.assign(bin.begin(), bin.end());
+        consensus.nSubsidyHalvingInterval = 210000;
+        consensus.BIP34Height = 1;
+        consensus.BIP34Hash = uint256{};
+        consensus.BIP65Height = 1;
+        consensus.BIP66Height = 1;
+        consensus.CSVHeight = 1;
+        consensus.SegwitHeight = 1;
+        consensus.nPowTargetTimespan = 14 * 24 * 60 * 60; // two weeks
+        consensus.nPowTargetSpacing = 10 * 60;
+        consensus.fPowAllowMinDifficultyBlocks = false;
+        consensus.fPowNoRetargeting = false;
+        consensus.nRuleChangeActivationThreshold = 1815; // 90% of 2016
+        consensus.nMinerConfirmationWindow = 2016; // nPowTargetTimespan / nPowTargetSpacing
+        consensus.MinBIP9WarningHeight = 0;
+        consensus.powLimit = uint256S("00000377ae000000000000000000000000000000000000000000000000000000");
+        consensus.vDeployments[Consensus::DEPLOYMENT_TESTDUMMY].bit = 28;
+        consensus.vDeployments[Consensus::DEPLOYMENT_TESTDUMMY].nStartTime = Consensus::BIP9Deployment::NEVER_ACTIVE;
+        consensus.vDeployments[Consensus::DEPLOYMENT_TESTDUMMY].nTimeout = Consensus::BIP9Deployment::NO_TIMEOUT;
+        consensus.vDeployments[Consensus::DEPLOYMENT_TESTDUMMY].min_activation_height = 0; // No activation delay
+
+        // Activation of Taproot (BIPs 340-342)
+        consensus.vDeployments[Consensus::DEPLOYMENT_TAPROOT].bit = 2;
+        consensus.vDeployments[Consensus::DEPLOYMENT_TAPROOT].nStartTime = Consensus::BIP9Deployment::ALWAYS_ACTIVE;
+        consensus.vDeployments[Consensus::DEPLOYMENT_TAPROOT].nTimeout = Consensus::BIP9Deployment::NO_TIMEOUT;
+        consensus.vDeployments[Consensus::DEPLOYMENT_TAPROOT].min_activation_height = 0; // No activation delay
+
+        // message start is defined as the first 4 bytes of the sha256d of the block script
+        HashWriter h{};
+        h << consensus.signet_challenge;
+        uint256 hash = h.GetHash();
+        memcpy(pchMessageStart, hash.begin(), 4);
+
+        nDefaultPort = 38333;
+        nPruneAfterHeight = 1000;
+
+        genesis = CreateGenesisBlock(1598918400, 52613770, 0x1e0377ae, 1, 50 * COIN);
+        consensus.hashGenesisBlock = genesis.GetHash();
+        assert(consensus.hashGenesisBlock == uint256S("0x00000008819873e925422c1ff0f99f7cc9bbb232af63a077a480a3633bee1ef6"));
+        assert(genesis.hashMerkleRoot == uint256S("0x4a5e1e4baab89f3a32518a88c31bc87f618f76673e2cc77ab2127b7afdeda33b"));
+
+        vFixedSeeds.clear();
+
+        base58Prefixes[PUBKEY_ADDRESS] = std::vector<unsigned char>(1,111);
+        base58Prefixes[SCRIPT_ADDRESS] = std::vector<unsigned char>(1,196);
+        base58Prefixes[SECRET_KEY] =     std::vector<unsigned char>(1,239);
+        base58Prefixes[EXT_PUBLIC_KEY] = {0x04, 0x35, 0x87, 0xCF};
+        base58Prefixes[EXT_SECRET_KEY] = {0x04, 0x35, 0x83, 0x94};
+
+        bech32_hrp = "tb";
+
+        fDefaultConsistencyChecks = false;
+        fRequireStandard = true;
+        m_is_test_chain = true;
+        m_is_mockable_chain = false;
+    }
+};
+
+/**
+ * Regression test: intended for private networks only. Has minimal difficulty to ensure that
+ * blocks can be found instantly.
+ */
+class CRegTestParams : public CChainParams
+{
+public:
+    explicit CRegTestParams(const RegTestOptions& opts)
+    {
+        strNetworkID =  CBaseChainParams::REGTEST;
+        consensus.signet_blocks = false;
+        consensus.signet_challenge.clear();
+        consensus.nSubsidyHalvingInterval = 150;
+        consensus.BIP34Height = 1; // Always active unless overridden
+        consensus.BIP34Hash = uint256();
+        consensus.BIP65Height = 1;  // Always active unless overridden
+        consensus.BIP66Height = 1;  // Always active unless overridden
+        consensus.CSVHeight = 1;    // Always active unless overridden
+        consensus.SegwitHeight = 0; // Always active unless overridden
+        consensus.MinBIP9WarningHeight = 0;
+        consensus.powLimit = uint256S("7fffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffff");
+        consensus.nPowTargetTimespan = 14 * 24 * 60 * 60; // two weeks
+        consensus.nPowTargetSpacing = 10 * 60;
+        consensus.fPowAllowMinDifficultyBlocks = true;
+        consensus.fPowNoRetargeting = true;
+        consensus.nRuleChangeActivationThreshold = 108; // 75% for testchains
+        consensus.nMinerConfirmationWindow = 144; // Faster than normal for regtest (144 instead of 2016)
+
+        consensus.vDeployments[Consensus::DEPLOYMENT_TESTDUMMY].bit = 28;
+        consensus.vDeployments[Consensus::DEPLOYMENT_TESTDUMMY].nStartTime = 0;
+        consensus.vDeployments[Consensus::DEPLOYMENT_TESTDUMMY].nTimeout = Consensus::BIP9Deployment::NO_TIMEOUT;
+        consensus.vDeployments[Consensus::DEPLOYMENT_TESTDUMMY].min_activation_height = 0; // No activation delay
+
+        consensus.vDeployments[Consensus::DEPLOYMENT_TAPROOT].bit = 2;
+        consensus.vDeployments[Consensus::DEPLOYMENT_TAPROOT].nStartTime = Consensus::BIP9Deployment::ALWAYS_ACTIVE;
+        consensus.vDeployments[Consensus::DEPLOYMENT_TAPROOT].nTimeout = Consensus::BIP9Deployment::NO_TIMEOUT;
+        consensus.vDeployments[Consensus::DEPLOYMENT_TAPROOT].min_activation_height = 0; // No activation delay
+
+        consensus.nMinimumChainWork = uint256{};
+        consensus.defaultAssumeValid = uint256{};
+
+        pchMessageStart[0] = 0xfa;
+        pchMessageStart[1] = 0xbf;
+        pchMessageStart[2] = 0xb5;
+        pchMessageStart[3] = 0xda;
+        nDefaultPort = 18444;
+        nPruneAfterHeight = opts.fastprune ? 100 : 1000;
+        m_assumed_blockchain_size = 0;
+        m_assumed_chain_state_size = 0;
+
+        for (const auto& [dep, height] : opts.activation_heights) {
+            switch (dep) {
+            case Consensus::BuriedDeployment::DEPLOYMENT_SEGWIT:
+                consensus.SegwitHeight = int{height};
+                break;
+            case Consensus::BuriedDeployment::DEPLOYMENT_HEIGHTINCB:
+                consensus.BIP34Height = int{height};
+                break;
+            case Consensus::BuriedDeployment::DEPLOYMENT_DERSIG:
+                consensus.BIP66Height = int{height};
+                break;
+            case Consensus::BuriedDeployment::DEPLOYMENT_CLTV:
+                consensus.BIP65Height = int{height};
+                break;
+            case Consensus::BuriedDeployment::DEPLOYMENT_CSV:
+                consensus.CSVHeight = int{height};
+                break;
+            }
+        }
+
+        for (const auto& [deployment_pos, version_bits_params] : opts.version_bits_parameters) {
+            consensus.vDeployments[deployment_pos].nStartTime = version_bits_params.start_time;
+            consensus.vDeployments[deployment_pos].nTimeout = version_bits_params.timeout;
+            consensus.vDeployments[deployment_pos].min_activation_height = version_bits_params.min_activation_height;
+        }
+
+        genesis = CreateGenesisBlock(1296688602, 2, 0x207fffff, 1, 50 * COIN);
+        consensus.hashGenesisBlock = genesis.GetHash();
+        assert(consensus.hashGenesisBlock == uint256S("0x0f9188f13cb7b2c71f2a335e3a4fc328bf5beb436012afca590b1a11466e2206"));
+        assert(genesis.hashMerkleRoot == uint256S("0x4a5e1e4baab89f3a32518a88c31bc87f618f76673e2cc77ab2127b7afdeda33b"));
+
+        vFixedSeeds.clear(); //!< Regtest mode doesn't have any fixed seeds.
+        vSeeds.clear();
+        vSeeds.emplace_back("dummySeed.invalid.");
+
+        fDefaultConsistencyChecks = true;
+        fRequireStandard = true;
+        m_is_test_chain = true;
+        m_is_mockable_chain = true;
+
+        checkpointData = {
+            {
+                {0, uint256S("0f9188f13cb7b2c71f2a335e3a4fc328bf5beb436012afca590b1a11466e2206")},
+            }
+        };
+
+        m_assumeutxo_data = MapAssumeutxo{
+            {
+                110,
+                {AssumeutxoHash{uint256S("0x1ebbf5850204c0bdb15bf030f47c7fe91d45c44c712697e4509ba67adb01c618")}, 110},
+            },
+            {
+                200,
+                {AssumeutxoHash{uint256S("0x51c8d11d8b5c1de51543c579736e786aa2736206d1e11e627568029ce092cf62")}, 200},
+            },
+        };
+
+        chainTxData = ChainTxData{
+            0,
+            0,
+            0
+        };
+
+        base58Prefixes[PUBKEY_ADDRESS] = std::vector<unsigned char>(1,111);
+        base58Prefixes[SCRIPT_ADDRESS] = std::vector<unsigned char>(1,196);
+        base58Prefixes[SECRET_KEY] =     std::vector<unsigned char>(1,239);
+        base58Prefixes[EXT_PUBLIC_KEY] = {0x04, 0x35, 0x87, 0xCF};
+        base58Prefixes[EXT_SECRET_KEY] = {0x04, 0x35, 0x83, 0x94};
+
+        bech32_hrp = "bcrt";
+    }
+};
+
+std::unique_ptr<const CChainParams> CChainParams::SigNet(const SigNetOptions& options)
+{
+    return std::make_unique<const SigNetParams>(options);
+}
+
+std::unique_ptr<const CChainParams> CChainParams::RegTest(const RegTestOptions& options)
+{
+    return std::make_unique<const CRegTestParams>(options);
+}
+
+std::unique_ptr<const CChainParams> CChainParams::Main()
+{
+    return std::make_unique<const CMainParams>();
+}
+
+std::unique_ptr<const CChainParams> CChainParams::TestNet()
+{
+    return std::make_unique<const CTestNetParams>();
+}
diff --git a/src/kernel/chainparams.h b/src/kernel/chainparams.h
new file mode 100644
index 0000000000..32fe618dbd
--- /dev/null
+++ b/src/kernel/chainparams.h
@@ -0,0 +1,187 @@
+// Copyright (c) 2009-2010 Satoshi Nakamoto
+// Copyright (c) 2009-2021 The Bitcoin Core developers
+// Distributed under the MIT software license, see the accompanying
+// file COPYING or http://www.opensource.org/licenses/mit-license.php.
+
+#ifndef BITCOIN_KERNEL_CHAINPARAMS_H
+#define BITCOIN_KERNEL_CHAINPARAMS_H
+
+#include <consensus/params.h>
+#include <netaddress.h>
+#include <primitives/block.h>
+#include <protocol.h>
+#include <uint256.h>
+#include <util/hash_type.h>
+
+#include <cstdint>
+#include <iterator>
+#include <map>
+#include <memory>
+#include <optional>
+#include <string>
+#include <unordered_map>
+#include <utility>
+#include <vector>
+
+typedef std::map<int, uint256> MapCheckpoints;
+
+struct CCheckpointData {
+    MapCheckpoints mapCheckpoints;
+
+    int GetHeight() const {
+        const auto& final_checkpoint = mapCheckpoints.rbegin();
+        return final_checkpoint->first /* height */;
+    }
+};
+
+struct AssumeutxoHash : public BaseHash<uint256> {
+    explicit AssumeutxoHash(const uint256& hash) : BaseHash(hash) {}
+};
+
+/**
+ * Holds configuration for use during UTXO snapshot load and validation. The contents
+ * here are security critical, since they dictate which UTXO snapshots are recognized
+ * as valid.
+ */
+struct AssumeutxoData {
+    //! The expected hash of the deserialized UTXO set.
+    const AssumeutxoHash hash_serialized;
+
+    //! Used to populate the nChainTx value, which is used during BlockManager::LoadBlockIndex().
+    //!
+    //! We need to hardcode the value here because this is computed cumulatively using block data,
+    //! which we do not necessarily have at the time of snapshot load.
+    const unsigned int nChainTx;
+};
+
+using MapAssumeutxo = std::map<int, const AssumeutxoData>;
+
+/**
+ * Holds various statistics on transactions within a chain. Used to estimate
+ * verification progress during chain sync.
+ *
+ * See also: CChainParams::TxData, GuessVerificationProgress.
+ */
+struct ChainTxData {
+    int64_t nTime;    //!< UNIX timestamp of last known number of transactions
+    int64_t nTxCount; //!< total number of transactions between genesis and that timestamp
+    double dTxRate;   //!< estimated number of transactions per second after that timestamp
+};
+
+/**
+ * CChainParams defines various tweakable parameters of a given instance of the
+ * Bitcoin system.
+ */
+class CChainParams
+{
+public:
+    enum Base58Type {
+        PUBKEY_ADDRESS,
+        SCRIPT_ADDRESS,
+        SECRET_KEY,
+        EXT_PUBLIC_KEY,
+        EXT_SECRET_KEY,
+
+        MAX_BASE58_TYPES
+    };
+
+    const Consensus::Params& GetConsensus() const { return consensus; }
+    const CMessageHeader::MessageStartChars& MessageStart() const { return pchMessageStart; }
+    uint16_t GetDefaultPort() const { return nDefaultPort; }
+    uint16_t GetDefaultPort(Network net) const
+    {
+        return net == NET_I2P ? I2P_SAM31_PORT : GetDefaultPort();
+    }
+    uint16_t GetDefaultPort(const std::string& addr) const
+    {
+        CNetAddr a;
+        return a.SetSpecial(addr) ? GetDefaultPort(a.GetNetwork()) : GetDefaultPort();
+    }
+
+    const CBlock& GenesisBlock() const { return genesis; }
+    /** Default value for -checkmempool and -checkblockindex argument */
+    bool DefaultConsistencyChecks() const { return fDefaultConsistencyChecks; }
+    /** Policy: Filter transactions that do not match well-defined patterns */
+    bool RequireStandard() const { return fRequireStandard; }
+    /** If this chain is exclusively used for testing */
+    bool IsTestChain() const { return m_is_test_chain; }
+    /** If this chain allows time to be mocked */
+    bool IsMockableChain() const { return m_is_mockable_chain; }
+    uint64_t PruneAfterHeight() const { return nPruneAfterHeight; }
+    /** Minimum free space (in GB) needed for data directory */
+    uint64_t AssumedBlockchainSize() const { return m_assumed_blockchain_size; }
+    /** Minimum free space (in GB) needed for data directory when pruned; Does not include prune target*/
+    uint64_t AssumedChainStateSize() const { return m_assumed_chain_state_size; }
+    /** Whether it is possible to mine blocks on demand (no retargeting) */
+    bool MineBlocksOnDemand() const { return consensus.fPowNoRetargeting; }
+    /** Return the network string */
+    std::string NetworkIDString() const { return strNetworkID; }
+    /** Return the list of hostnames to look up for DNS seeds */
+    const std::vector<std::string>& DNSSeeds() const { return vSeeds; }
+    const std::vector<unsigned char>& Base58Prefix(Base58Type type) const { return base58Prefixes[type]; }
+    const std::string& Bech32HRP() const { return bech32_hrp; }
+    const std::vector<uint8_t>& FixedSeeds() const { return vFixedSeeds; }
+    const CCheckpointData& Checkpoints() const { return checkpointData; }
+
+    //! Get allowed assumeutxo configuration.
+    //! @see ChainstateManager
+    const MapAssumeutxo& Assumeutxo() const { return m_assumeutxo_data; }
+
+    const ChainTxData& TxData() const { return chainTxData; }
+
+    /**
+     * SigNetOptions holds configurations for creating a signet CChainParams.
+     */
+    struct SigNetOptions {
+        std::optional<std::vector<uint8_t>> challenge{};
+        std::optional<std::vector<std::string>> seeds{};
+    };
+
+    /**
+     * VersionBitsParameters holds activation parameters
+     */
+    struct VersionBitsParameters {
+        int64_t start_time;
+        int64_t timeout;
+        int min_activation_height;
+    };
+
+    /**
+     * RegTestOptions holds configurations for creating a regtest CChainParams.
+     */
+    struct RegTestOptions {
+        std::unordered_map<Consensus::DeploymentPos, VersionBitsParameters> version_bits_parameters{};
+        std::unordered_map<Consensus::BuriedDeployment, int> activation_heights{};
+        bool fastprune{false};
+    };
+
+    static std::unique_ptr<const CChainParams> RegTest(const RegTestOptions& options);
+    static std::unique_ptr<const CChainParams> SigNet(const SigNetOptions& options);
+    static std::unique_ptr<const CChainParams> Main();
+    static std::unique_ptr<const CChainParams> TestNet();
+
+protected:
+    CChainParams() {}
+
+    Consensus::Params consensus;
+    CMessageHeader::MessageStartChars pchMessageStart;
+    uint16_t nDefaultPort;
+    uint64_t nPruneAfterHeight;
+    uint64_t m_assumed_blockchain_size;
+    uint64_t m_assumed_chain_state_size;
+    std::vector<std::string> vSeeds;
+    std::vector<unsigned char> base58Prefixes[MAX_BASE58_TYPES];
+    std::string bech32_hrp;
+    std::string strNetworkID;
+    CBlock genesis;
+    std::vector<uint8_t> vFixedSeeds;
+    bool fDefaultConsistencyChecks;
+    bool fRequireStandard;
+    bool m_is_test_chain;
+    bool m_is_mockable_chain;
+    CCheckpointData checkpointData;
+    MapAssumeutxo m_assumeutxo_data;
+    ChainTxData chainTxData;
+};
+
+#endif // BITCOIN_KERNEL_CHAINPARAMS_H