Merge #958: Some minor dynafed improvements

14a42a0 Add two missing dynafed fields to getblockchaininfo (Steven Roose) fe03729 dynafed: Support changing mainnet dynafed activation (Steven Roose) ce7a93d dynafed: Only verify proposed parameters if they differ from current (Steven Roose) Pull request description: - support blocksigners specifying their own activation to make coordination a bit more flexible - don't force fedpeg script to change in order to change the block signing script Tree-SHA512: 8dd66440261f910b083f7ed461e1930c9380350e3648f6aca44726c39dcca3bb7e62c36d36ae56c2717827fbaee2b9046c6ce0b05441c1d8d1b54f3c284bc4d7
ElementsProject · Mar 2, 2021 · 3b8e407 · 3b8e407
2 parents a993a7c + 14a42a0
commit 3b8e407
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Showing 4 changed files with 58 additions and 40 deletions.
diff --git a/src/chainparams.cpp b/src/chainparams.cpp
@@ -860,9 +860,10 @@ class CLiquidV1Params : public CChainParams {
         consensus.vDeployments[Consensus::DEPLOYMENT_TESTDUMMY].nStartTime = 0;
         consensus.vDeployments[Consensus::DEPLOYMENT_TESTDUMMY].nTimeout = Consensus::BIP9Deployment::NO_TIMEOUT;
 
-        // Not active yet.
+        // Activated from block 1,000,000.
         consensus.vDeployments[Consensus::DEPLOYMENT_DYNA_FED].bit = 25;
-        consensus.vDeployments[Consensus::DEPLOYMENT_DYNA_FED].nStartTime = 1000000;
+        // Allow blocksigners to delay activation.
+        consensus.vDeployments[Consensus::DEPLOYMENT_DYNA_FED].nStartTime = gArgs.GetArg("-con_dyna_deploy_start", 1000000);
         consensus.vDeployments[Consensus::DEPLOYMENT_DYNA_FED].nTimeout = Consensus::BIP9Deployment::NO_TIMEOUT;
 
 

diff --git a/src/rpc/blockchain.cpp b/src/rpc/blockchain.cpp
@@ -1464,6 +1464,8 @@ UniValue getblockchaininfo(const JSONRPCRequest& request)
             obj.pushKV("current_signblock_asm", ScriptToAsmStr(entry.m_signblockscript));
             obj.pushKV("current_signblock_hex", HexStr(entry.m_signblockscript));
             obj.pushKV("max_block_witness", (uint64_t)entry.m_signblock_witness_limit);
+            obj.pushKV("current_fedpeg_program", HexStr(entry.m_fedpeg_program));
+            obj.pushKV("current_fedpeg_script", HexStr(entry.m_fedpegscript));
             UniValue arr(UniValue::VARR);
             for (const auto& extension : entry.m_extension_space) {
                 arr.push_back(HexStr(extension));

diff --git a/src/validation.cpp b/src/validation.cpp
@@ -3502,49 +3502,62 @@ static bool ContextualCheckDynaFedHeader(const CBlockHeader& block, CValidationS
         return state.Invalid(false, REJECT_INVALID, "invalid-dyna-fed", "dynamic block header's current parameters do not match expected");
     }
 
-    // Lastly, enforce rules on proposals.
-    const DynaFedParamEntry& proposed = dynafed_params.m_proposed;
-    if (!proposed.IsNull()) {
-
-        // signblockscript proposals *must* be segwit versions
-        int block_version = 0;
-        std::vector<unsigned char> block_program;
-        if (!proposed.m_signblockscript.IsWitnessProgram(block_version, block_program)) {
-            return state.Invalid(false, REJECT_INVALID, "invalid-dyna-fed", "proposed signblockscript must be native segwit scriptPubkey");
-        }
-
-        int fedpeg_version = 0;
-        std::vector<unsigned char> fedpeg_program;
-        if (!proposed.m_fedpeg_program.IsWitnessProgram(fedpeg_version, fedpeg_program)) {
-            return state.Invalid(false, REJECT_INVALID, "invalid-dyna-fed", "proposed fedpegs program must be native segwit scriptPubkey");
-        }
-
-        // for v0, fedpegscript's scriptPubKey must match. v1+ is unencumbered.
-        if (fedpeg_version == 0) {
-            uint256 fedpeg_program;
-            CSHA256().Write(proposed.m_fedpegscript.data(), proposed.m_fedpegscript.size()).Finalize(fedpeg_program.begin());
-            CScript computed_program = CScript() << OP_0 << ToByteVector(fedpeg_program);
-            if (computed_program != proposed.m_fedpeg_program) {
-                return state.Invalid(false, REJECT_INVALID, "invalid-dyna-fed", "proposed v0 segwit fedpegscript must match proposed fedpeg witness program");
+    // Lastly, enforce rules on proposals if they make changes.
+    if (!dynafed_params.m_proposed.IsNull()) {
+        // Compare the new proposed parameters with the current full parameters.
+        const DynaFedParamEntry current = ComputeNextBlockFullCurrentParameters(pindexPrev, params.GetConsensus());
+        const DynaFedParamEntry& proposed = dynafed_params.m_proposed;
+
+        if (proposed.m_signblockscript != current.m_signblockscript) {
+            // signblockscript proposals *must* be segwit versions
+            int block_version = 0;
+            std::vector<unsigned char> block_program;
+            if (!proposed.m_signblockscript.IsWitnessProgram(block_version, block_program)) {
+                return state.Invalid(false, REJECT_INVALID, "invalid-dyna-fed",
+                    "proposed signblockscript must be native segwit scriptPubkey"
+                );
             }
+        }
 
-            // fedpegscript proposals *must not* start with OP_DEPTH
-            // This forbids the first Liquid watchman script which is a hack.
-            // Use miniscript, which doesn't even have OP_DEPTH.
-            // We don't encumber future segwit versions as opcodes may change.
-            if (!proposed.m_fedpegscript.empty() &&
-                    proposed.m_fedpegscript.front() == OP_DEPTH) {
-                return state.Invalid(false, REJECT_INVALID, "invalid-dyna-fed", "Proposed fedpegscript starts with OP_DEPTH, which is illegal");
+        if (proposed.m_fedpeg_program != current.m_fedpeg_program || proposed.m_fedpegscript != current.m_fedpegscript) {
+            int fedpeg_version = 0;
+            std::vector<unsigned char> fedpeg_program;
+            if (!proposed.m_fedpeg_program.IsWitnessProgram(fedpeg_version, fedpeg_program)) {
+                return state.Invalid(false, REJECT_INVALID, "invalid-dyna-fed", "proposed fedpegs program must be native segwit scriptPubkey");
+            }
+
+            // for v0, fedpegscript's scriptPubKey must match. v1+ is unencumbered.
+            if (fedpeg_version == 0) {
+                uint256 fedpeg_program;
+                CSHA256().Write(proposed.m_fedpegscript.data(), proposed.m_fedpegscript.size()).Finalize(fedpeg_program.begin());
+                CScript computed_program = CScript() << OP_0 << ToByteVector(fedpeg_program);
+                if (computed_program != proposed.m_fedpeg_program) {
+                    return state.Invalid(false, REJECT_INVALID, "invalid-dyna-fed",
+                        "proposed v0 segwit fedpegscript must match proposed fedpeg witness program"
+                    );
+                }
+
+                // fedpegscript proposals *must not* start with OP_DEPTH
+                // This forbids the first Liquid watchman script which is a hack.
+                // Use miniscript, which doesn't even have OP_DEPTH.
+                // We don't encumber future segwit versions as opcodes may change.
+                if (!proposed.m_fedpegscript.empty() && proposed.m_fedpegscript.front() == OP_DEPTH) {
+                    return state.Invalid(false, REJECT_INVALID, "invalid-dyna-fed", "Proposed fedpegscript starts with OP_DEPTH, which is illegal");
+                }
             }
         }
 
-        // When enforcing PAK, extension_space must give non-empty PAK list when
-        // the vector itself is non-empty. Otherwise this means there were "junk"
-        // entries
-        if (params.GetEnforcePak()) {
-            if (!proposed.m_extension_space.empty() &&
-                    CreatePAKListFromExtensionSpace(proposed.m_extension_space).IsReject()) {
-                return state.Invalid(false, REJECT_INVALID, "invalid-dyna-fed", "Extension space is not list of valid PAK entries");
+        if (proposed.m_extension_space != current.m_extension_space) {
+            // When enforcing PAK, extension_space must give non-empty PAK list when
+            // the vector itself is non-empty. Otherwise this means there were "junk"
+            // entries
+            if (params.GetEnforcePak()) {
+                if (!proposed.m_extension_space.empty() &&
+                        CreatePAKListFromExtensionSpace(proposed.m_extension_space).IsReject()) {
+                    return state.Invalid(false, REJECT_INVALID, "invalid-dyna-fed",
+                        "Extension space is not list of valid PAK entries"
+                    );
+                }
             }
         }
     }

diff --git a/test/functional/feature_dynafed.py b/test/functional/feature_dynafed.py
@@ -66,6 +66,8 @@ def set_test_params(self):
         self.extra_args = [["-con_dyna_deploy_start=1000", "-enforce_pak=1", "-con_parent_chain_signblockscript=51", "-peginconfirmationdepth=1", "-parentscriptprefix=75", "-parent_bech32_hrp=ert"] for i in range(self.num_nodes)]
         # second node will not mine transactions
         self.extra_args[1].append("-blocksonly=1")
+        # Make sure nothing breaks if peers have a different activation.
+        self.extra_args[1][0] = "-con_dyna_deploy_start=937"
 
     def skip_test_if_missing_module(self):
         self.skip_if_no_wallet()