Support signet as parent chain

signed has simpler signed blocks but no CT or any other extra feature

Author: jtimon

src/chainparams.cpp

@@ -6,7 +6,7 @@
 #include "chainparams.h"
 #include "consensus/merkle.h"
 #include "issuance.h"
-
+#include "primitives/bitcoin/block.h"
 #include "tinyformat.h"
 #include "util.h"
 #include "utilstrencodings.h"
@@ -131,6 +131,9 @@ class CCustomParams : public CChainParams {
         consensus.pegin_min_depth = GetArg("-peginconfirmationdepth", DEFAULT_PEGIN_CONFIRMATION_DEPTH);
         consensus.mandatory_coinbase_destination = StrHexToScriptWithDefault(GetArg("-con_mandatorycoinbase", ""), CScript()); // Blank script allows any coinbase destination
         consensus.parent_chain_signblockscript = StrHexToScriptWithDefault(GetArg("-con_parent_chain_signblockscript", ""), CScript());
+        consensus.parent_is_signet = GetBoolArg("-con_parent_is_signet", false);
+        g_solution_blocks = consensus.parent_is_signet;
+        g_solution_block_len = GetArg("-con_parent_signet_siglen", 77);
         consensus.parent_pegged_asset.SetHex(GetArg("-con_parent_pegged_asset", "0x00"));
 
         // bitcoin regtest is the parent chain by default

src/consensus/params.h

@@ -74,8 +74,10 @@ struct Params {
     CScript signblockscript;
     bool has_parent_chain;
     CScript parent_chain_signblockscript;
+    bool parent_is_signet;
     CAsset parent_pegged_asset;
-    bool ParentChainHasPow() const { return parent_chain_signblockscript == CScript();}
+    bool ParentChainHasPow() const { return parent_chain_signblockscript == CScript(); }
+    bool ParentChainIsBitcoinLike() const { return parent_is_signet || ParentChainHasPow(); }
 };
 } // namespace Consensus
 

src/init.cpp

@@ -519,6 +519,8 @@ std::string HelpMessage(HelpMessageMode mode)
         strUsage += HelpMessageOpt("-parentpubkeyprefix", strprintf(_("The byte prefix, in decimal, of the parent chain's base58 pubkey address. (default: %d)"), 111));
         strUsage += HelpMessageOpt("-parentscriptprefix", strprintf(_("The byte prefix, in decimal, of the parent chain's base58 script address. (default: %d)"), 196));
         strUsage += HelpMessageOpt("-con_parent_chain_signblockscript", _("Whether parent chain uses pow or signed blocks. If the parent chain uses signed blocks, the challenge (scriptPubKey) script. If not, an empty string. (default: empty script [ie parent uses pow])"));
+        strUsage += HelpMessageOpt("-con_parent_is_signet", _("If parent chain uses signed blocks, whether it is an elements based chain or one based on signet (default: false)"));
+        strUsage += HelpMessageOpt("-con_parent_signet_siglen", _("If parent chain uses signed blocks based on signet, The length of the signature must be exactly this long (padded to this length, if shorter). All block headers in this network are of length 80 + this value. (default: 77)"));
         strUsage += HelpMessageOpt("-con_parent_pegged_asset=<hex>", _("Asset ID (hex) for pegged asset for when parent chain has CA. (default: 0x00)"));
     }
     strUsage += HelpMessageOpt("-validatepegin", strprintf(_("Validate peg-in claims. An RPC connection will be attempted to the trusted bitcoind using the `mainchain*` settings below. All functionaries must run this enabled. (default: %u)"), DEFAULT_VALIDATE_PEGIN));

src/rpc/blockchain.cpp

@@ -1112,6 +1112,8 @@ UniValue getsidechaininfo(const JSONRPCRequest& request)
             "  \"min_peg_diff\" : \"xxxx\",        (string) The minimum difficulty parent chain header target. Peg-in headers that have less work will be rejected as an anti-Dos measure.\n"
             "  \"parent_blockhash\" : \"xxxx\",    (string) The parent genesis blockhash as source of pegged-in funds.\n"
             "  \"parent_chain_has_pow\": \"xxxx\", (boolean) Whether parent chain has pow or signed blocks.\n"
+            "  \"parent_chain_is_signet\": \"xxxx\", (boolean) If parent chain uses signed blocks, whether it is an elements based chain or one based on signet.\n"
+            "  \"parent_chain_signet_siglen\": \"xxxx\", (numeric) If parent chain uses signed blocks based on signet, The length of the signature must be exactly this long (padded to this length, if shorter). All block headers in this network are of length 80 + this value.\n"
             "  \"parent_chain_signblockscript_asm\": \"xxxx\", (string) If the parent chain has signed blocks, its signblockscript in ASM.\n"
             "  \"parent_chain_signblockscript_hex\": \"xxxx\", (string) If the parent chain has signed blocks, its signblockscript in hex.\n"
             "  \"parent_pegged_asset\": \"xxxx\",  (boolean) If the parent chain has Confidential Assets, the asset id of the pegged asset in that chain.\n"
@@ -1133,6 +1135,10 @@ UniValue getsidechaininfo(const JSONRPCRequest& request)
     obj.push_back(Pair("parent_blockhash", parent_blockhash.GetHex()));
     obj.push_back(Pair("parent_chain_has_pow", consensus.ParentChainHasPow()));
     if (!consensus.ParentChainHasPow()) {
+        obj.push_back(Pair("parent_chain_is_signet", consensus.parent_is_signet));
+        if (consensus.parent_is_signet) {
+            obj.push_back(Pair("parent_chain_signet_siglen", (uint64_t)g_solution_block_len));
+        }
         obj.push_back(Pair("parent_chain_signblockscript_asm", ScriptToAsmStr(consensus.parent_chain_signblockscript)));
         obj.push_back(Pair("parent_chain_signblockscript_hex", HexStr(consensus.parent_chain_signblockscript)));
         obj.push_back(Pair("parent_pegged_asset", HexStr(consensus.parent_pegged_asset)));

src/validation.cpp

@@ -2533,7 +2533,7 @@ bool IsValidPeginWitness(const CScriptWitness& pegin_witness, const COutPoint& p
     uint256 tx_hash;
     int num_txs;
     // Get txout proof
-    if (Params().GetConsensus().ParentChainHasPow()) {
+    if (Params().GetConsensus().ParentChainIsBitcoinLike()) {
 
         Sidechain::Bitcoin::CMerkleBlock merkle_block_pow;
         if (!GetBlockAndTxFromMerkleBlock(block_hash, tx_hash, merkle_block_pow, stack[5])) {

src/wallet/rpcwallet.cpp

@@ -3716,7 +3716,7 @@ static UniValue createrawpegin(const JSONRPCRequest& request, T_tx_ref& txBTCRef
 UniValue createrawpegin(const JSONRPCRequest& request)
 {
     UniValue ret(UniValue::VOBJ);
-    if (Params().GetConsensus().ParentChainHasPow()) {
+    if (Params().GetConsensus().ParentChainIsBitcoinLike()) {
         Sidechain::Bitcoin::CTransactionRef txBTCRef;
         Sidechain::Bitcoin::CTransaction tx_aux;
         Sidechain::Bitcoin::CMerkleBlock merkleBlock;