Merge #18267: BIP-325: Signet [consensus]

8258c4c0076bb5f27efdc117a04b27fcd6dd00b2 test: some sanity checks for consensus logic (Anthony Towns)
e47ad375bf17557f805bd206e789b8db78c6338a test: basic signet tests (Karl-Johan Alm)
4c189abdc452f08dfa758564b5381bc78c42d481 test: add small signet fuzzer (practicalswift)
ec9b25d046793be50da1c11ba61d1b4b13b295b0 test: signet network selection tests (Karl-Johan Alm)
3efe298dccb248f25d6b01ab6a80b1cd6c9e1a1e signet: hard-coded parameters for Signet Global Network VI (2020-09-07) (Karl-Johan Alm)
c7898bca4e1ccbc6edafd3b72eaf80df38e3af32 qt: update QT to support signet network (Karl-Johan Alm)
a8de47a1c9033fac3355590f1fe2158a95011bb3 consensus: add signet validation (Karl-Johan Alm)
e8990f121405af8cd539b904ef082439261e6c93 add signet chain and accompanying parameters (Karl-Johan Alm)
404682b7cdb54494e7c98f0ba0cac8b51f379750 add signet basic support (signet.cpp) (Karl-Johan Alm)
a2147d7dadec1febcd9c2b8ebbbf78dce6d0556b validation: move GetWitnessCommitmentIndex to consensus/validation (Karl-Johan Alm)

Pull request description:

  This PR is a part of BIP-325 (https://github.com/bitcoin/bips/blob/master/bip-0325.mediawiki), and is a sub-PR of #16411.

  * Signet consensus (this)
  * Signet RPC tools (pending)
  * Signet utility scripts (contrib/signet) (pending)

ACKs for top commit:
  jonatack:
    re-ACK 8258c4c0076bb5f27efdc117a04b27fcd6dd00b per `git diff dbeea65 8258c4c`, only change since last review is updated `-signet*` config option naming.
  fjahr:
    re-ACK 8258c4c
  laanwj:
    ACK 8258c4c0076bb5f27efdc117a04b27fcd6dd00b2
  MarcoFalke:
    Approach ACK 8258c4c007 🌵

Tree-SHA512: 5d158add96755910837feafa8214e13695b769a6aec3a2da753cf672618bef377fac43b0f4b772a87b25dd9f0c1c9b29f2789785d7a7d47a155cdcf48f7c975d

1 files changed, 11 insertions, 5 deletions

diff --git a/src/chainparamsbase.cpp b/src/chainparamsbase.cpp
index 1825ced640..034e897ca6 100644
--- a/src/chainparamsbase.cpp
+++ b/src/chainparamsbase.cpp
@@ -13,6 +13,7 @@
 
 const std::string CBaseChainParams::MAIN = "main";
 const std::string CBaseChainParams::TESTNET = "test";
+const std::string CBaseChainParams::SIGNET = "signet";
 const std::string CBaseChainParams::REGTEST = "regtest";
 
 void SetupChainParamsBaseOptions(ArgsManager& argsman)
@@ -23,6 +24,9 @@ void SetupChainParamsBaseOptions(ArgsManager& argsman)
     argsman.AddArg("-segwitheight=<n>", "Set the activation height of segwit. -1 to disable. (regtest-only)", ArgsManager::ALLOW_ANY | ArgsManager::DEBUG_ONLY, OptionsCategory::DEBUG_TEST);
     argsman.AddArg("-testnet", "Use the test chain. Equivalent to -chain=test.", ArgsManager::ALLOW_ANY, OptionsCategory::CHAINPARAMS);
     argsman.AddArg("-vbparams=deployment:start:end", "Use given start/end times for specified version bits deployment (regtest-only)", ArgsManager::ALLOW_ANY | ArgsManager::DEBUG_ONLY, OptionsCategory::CHAINPARAMS);
+    argsman.AddArg("-signet", "Use the signet chain. Note that the network is defined by the -signetchallenge parameter", ArgsManager::ALLOW_ANY, OptionsCategory::CHAINPARAMS);
+    argsman.AddArg("-signetchallenge", "Blocks must satisfy the given script to be considered valid (only for signet networks; defaults to the global default signet test network challenge)", ArgsManager::ALLOW_STRING, OptionsCategory::CHAINPARAMS);
+    argsman.AddArg("-signetseednode", "Specify a seed node for the signet network, in the hostname[:port] format, e.g. sig.net:1234 (may be used multiple times to specify multiple seed nodes; defaults to the global default signet test network seed node(s))", ArgsManager::ALLOW_STRING, OptionsCategory::CHAINPARAMS);
 }
 
 static std::unique_ptr<CBaseChainParams> globalChainBaseParams;
@@ -35,14 +39,16 @@ const CBaseChainParams& BaseParams()
 
 std::unique_ptr<CBaseChainParams> CreateBaseChainParams(const std::string& chain)
 {
-    if (chain == CBaseChainParams::MAIN)
+    if (chain == CBaseChainParams::MAIN) {
         return MakeUnique<CBaseChainParams>("", 8332);
-    else if (chain == CBaseChainParams::TESTNET)
+    } else if (chain == CBaseChainParams::TESTNET) {
         return MakeUnique<CBaseChainParams>("testnet3", 18332);
-    else if (chain == CBaseChainParams::REGTEST)
+    } else if (chain == CBaseChainParams::SIGNET) {
+        return MakeUnique<CBaseChainParams>("signet", 38332);
+    } else if (chain == CBaseChainParams::REGTEST) {
         return MakeUnique<CBaseChainParams>("regtest", 18443);
-    else
-        throw std::runtime_error(strprintf("%s: Unknown chain %s.", __func__, chain));
+    }
+    throw std::runtime_error(strprintf("%s: Unknown chain %s.", __func__, chain));
 }
 
 void SelectBaseParams(const std::string& chain)