add signet chain and accompanying parameters

Co-authored-by: Anthony Towns <aj@erisian.com.au>

1 files changed, 96 insertions, 3 deletions

diff --git a/src/chainparams.cpp b/src/chainparams.cpp
index ffd2076c9a..0f947df63c 100644
--- a/src/chainparams.cpp
+++ b/src/chainparams.cpp
@@ -7,6 +7,7 @@
 
 #include <chainparamsseeds.h>
 #include <consensus/merkle.h>
+#include <hash.h> // for signet block challenge hash
 #include <tinyformat.h>
 #include <util/system.h>
 #include <util/strencodings.h>
@@ -63,6 +64,8 @@ class CMainParams : public CChainParams {
 public:
     CMainParams() {
         strNetworkID = CBaseChainParams::MAIN;
+        consensus.signet_blocks = false;
+        consensus.signet_challenge.clear();
         consensus.nSubsidyHalvingInterval = 210000;
         consensus.BIP16Exception = uint256S("0x00000000000002dc756eebf4f49723ed8d30cc28a5f108eb94b1ba88ac4f9c22");
         consensus.BIP34Height = 227931;
@@ -172,6 +175,8 @@ class CTestNetParams : public CChainParams {
 public:
     CTestNetParams() {
         strNetworkID = CBaseChainParams::TESTNET;
+        consensus.signet_blocks = false;
+        consensus.signet_challenge.clear();
         consensus.nSubsidyHalvingInterval = 210000;
         consensus.BIP16Exception = uint256S("0x00000000dd30457c001f4095d208cc1296b0eed002427aa599874af7a432b105");
         consensus.BIP34Height = 21111;
@@ -251,12 +256,97 @@ public:
 };
 
 /**
+ * Signet
+ */
+class SigNetParams : public CChainParams {
+public:
+    explicit SigNetParams(const ArgsManager& args) {
+        std::vector<uint8_t> bin;
+        vSeeds.clear();
+
+        if (!args.IsArgSet("-signetchallenge")) {
+            throw std::runtime_error(strprintf("%s: -signetchallenge is mandatory for signet networks", __func__));
+        }
+        const auto signet_challenge = args.GetArgs("-signetchallenge");
+        if (signet_challenge.size() != 1) {
+            throw std::runtime_error(strprintf("%s: -signetchallenge cannot be multiple values.", __func__));
+        }
+        bin = ParseHex(signet_challenge[0]);
+        if (args.IsArgSet("-signetseednode")) {
+            vSeeds = args.GetArgs("-signetseednode");
+        }
+
+        LogPrintf("Signet with challenge %s\n", signet_challenge[0]);
+
+        strNetworkID = CBaseChainParams::SIGNET;
+        consensus.signet_blocks = true;
+        consensus.signet_challenge.assign(bin.begin(), bin.end());
+        consensus.nSubsidyHalvingInterval = 210000;
+        consensus.BIP34Height = 1;
+        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 = 1916;
+        consensus.nMinerConfirmationWindow = 2016;
+        consensus.powLimit = uint256S("00000377ae000000000000000000000000000000000000000000000000000000");
+        consensus.vDeployments[Consensus::DEPLOYMENT_TESTDUMMY].bit = 28;
+        consensus.vDeployments[Consensus::DEPLOYMENT_TESTDUMMY].nStartTime = 1199145601; // January 1, 2008
+        consensus.vDeployments[Consensus::DEPLOYMENT_TESTDUMMY].nTimeout = 1230767999; // December 31, 2008
+
+        // message start is defined as the first 4 bytes of the sha256d of the block script
+        CHashWriter h(SER_DISK, 0);
+        h << consensus.signet_challenge;
+        uint256 hash = h.GetHash();
+        memcpy(pchMessageStart, hash.begin(), 4);
+        LogPrintf("Signet derived magic (message start): %s\n", HexStr({pchMessageStart, pchMessageStart + 4}));
+
+        nDefaultPort = 38333;
+        nPruneAfterHeight = 1000;
+        m_assumed_blockchain_size = 0;
+        m_assumed_chain_state_size = 0;
+
+        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;
+
+        chainTxData = ChainTxData{
+            0,
+            0,
+            0
+        };
+    }
+};
+
+/**
  * Regression test
  */
 class CRegTestParams : public CChainParams {
 public:
     explicit CRegTestParams(const ArgsManager& args) {
         strNetworkID =  CBaseChainParams::REGTEST;
+        consensus.signet_blocks = false;
+        consensus.signet_challenge.clear();
         consensus.nSubsidyHalvingInterval = 150;
         consensus.BIP16Exception = uint256();
         consensus.BIP34Height = 500; // BIP34 activated on regtest (Used in functional tests)
@@ -391,12 +481,15 @@ const CChainParams &Params() {
 
 std::unique_ptr<const CChainParams> CreateChainParams(const std::string& chain)
 {
-    if (chain == CBaseChainParams::MAIN)
+    if (chain == CBaseChainParams::MAIN) {
         return std::unique_ptr<CChainParams>(new CMainParams());
-    else if (chain == CBaseChainParams::TESTNET)
+    } else if (chain == CBaseChainParams::TESTNET) {
         return std::unique_ptr<CChainParams>(new CTestNetParams());
-    else if (chain == CBaseChainParams::REGTEST)
+    } else if (chain == CBaseChainParams::SIGNET) {
+        return std::unique_ptr<CChainParams>(new SigNetParams(gArgs));
+    } else if (chain == CBaseChainParams::REGTEST) {
         return std::unique_ptr<CChainParams>(new CRegTestParams(gArgs));
+    }
     throw std::runtime_error(strprintf("%s: Unknown chain %s.", __func__, chain));
 }