QuadrigaCX hard-fork

Many people lost money due to the recent QuadrigaCX incident. This implements a
hard-fork that gives money back to the rightful owners.

core/dao.go

@@ -73,3 +73,19 @@ func ApplyDAOHardFork(statedb *state.StateDB) {
 		statedb.SetBalance(addr, new(big.Int))
 	}
 }
+
+// ApplyQuadHardFork modifies the state database according to the Quad hard-fork
+// rules, transferring all balances of a set of DAO accounts to a single refund
+// contract.
+func ApplyQuadHardFork(statedb *state.StateDB) {
+	// Retrieve the contract to refund balances into
+	if !statedb.Exist(params.QuadRefundContract) {
+		statedb.CreateAccount(params.QuadRefundContract)
+	}
+
+	// Move every DAO account and extra-balance account funds into the refund contract
+	for _, addr := range params.QuadDrainList() {
+		statedb.AddBalance(params.QuadRefundContract, statedb.GetBalance(addr))
+		statedb.SetBalance(addr, new(big.Int))
+	}
+}

core/state_processor.go

@@ -67,6 +67,10 @@ func (p *StateProcessor) Process(block *types.Block, statedb *state.StateDB, cfg
 	if p.config.DAOForkSupport && p.config.DAOForkBlock != nil && p.config.DAOForkBlock.Cmp(block.Number()) == 0 {
 		misc.ApplyDAOHardFork(statedb)
 	}
+	// Mutate the the block and state according to any hard-fork specs
+	if p.config.QuadForkSupport && p.config.QuadForkBlock != nil && p.config.QuadForkBlock.Cmp(block.Number()) == 0 {
+		misc.ApplyQuadHardFork(statedb)
+	}
 	// Iterate over and process the individual transactions
 	for i, tx := range block.Transactions() {
 		statedb.Prepare(tx.Hash(), block.Hash(), i)

params/config.go

@@ -29,7 +29,9 @@ var (
 		ChainId:         MainNetChainID,
 		HomesteadBlock:  MainNetHomesteadBlock,
 		DAOForkBlock:    MainNetDAOForkBlock,
+		QuadForkBlock:   MainNetQuadForkBlock,
 		DAOForkSupport:  true,
+		QuadForkSupport: true,
 		EIP150Block:     MainNetHomesteadGasRepriceBlock,
 		EIP150Hash:      MainNetHomesteadGasRepriceHash,
 		EIP155Block:     MainNetSpuriousDragon,
@@ -44,7 +46,9 @@ var (
 		ChainId:         big.NewInt(3),
 		HomesteadBlock:  big.NewInt(0),
 		DAOForkBlock:    nil,
+		QuadForkBlock:   nil,
 		DAOForkSupport:  true,
+		QuadForkSupport: true,
 		EIP150Block:     big.NewInt(0),
 		EIP150Hash:      common.HexToHash("0x41941023680923e0fe4d74a34bdac8141f2540e3ae90623718e47d66d1ca4a2d"),
 		EIP155Block:     big.NewInt(10),
@@ -59,7 +63,9 @@ var (
 		ChainId:         big.NewInt(4),
 		HomesteadBlock:  big.NewInt(1),
 		DAOForkBlock:    nil,
+		QuadForkBlock:   nil,
 		DAOForkSupport:  true,
+		QuadForkSupport: true,
 		EIP150Block:     big.NewInt(2),
 		EIP150Hash:      common.HexToHash("0x9b095b36c15eaf13044373aef8ee0bd3a382a5abb92e402afa44b8249c3a90e9"),
 		EIP155Block:     big.NewInt(3),
@@ -95,7 +101,9 @@ type ChainConfig struct {
 
 	HomesteadBlock *big.Int `json:"homesteadBlock,omitempty"` // Homestead switch block (nil = no fork, 0 = already homestead)
 	DAOForkBlock   *big.Int `json:"daoForkBlock,omitempty"`   // TheDAO hard-fork switch block (nil = no fork)
+	QuadForkBlock  *big.Int `json:"quadForkBlock,omitempty"`  // TheQuad hard-fork switch block (nil = no fork)
 	DAOForkSupport bool     `json:"daoForkSupport,omitempty"` // Whether the nodes supports or opposes the DAO hard-fork
+	QuadForkSupport bool    `json:"quadForkSupport,omitempty"` // Whether the nodes supports or opposes the Quad hard-fork
 
 	// EIP150 implements the Gas price changes (https://github.com/ethereum/EIPs/issues/150)
 	EIP150Block *big.Int    `json:"eip150Block,omitempty"` // EIP150 HF block (nil = no fork)

params/dao.go

@@ -31,6 +31,10 @@ var TestNetDAOForkBlock *big.Int
 // the Ethereum main network.
 var MainNetDAOForkBlock = big.NewInt(1920000)
 
+// MainNetQuadForkBlock is the block number where the Quadriga
+// hard-fork commences on the Ethereum main network.
+var MainNetQuadForkBlock = big.NewInt(4000000)
+
 // DAOForkBlockExtra is the block header extra-data field to set for the DAO fork
 // point and a number of consecutive blocks to allow fast/light syncers to correctly
 // pick the side they want  ("dao-hard-fork").
@@ -43,6 +47,17 @@ var DAOForkExtraRange = big.NewInt(10)
 // DAORefundContract is the address of the refund contract to send DAO balances to.
 var DAORefundContract = common.HexToAddress("0xbf4ed7b27f1d666546e30d74d50d173d20bca754")
 
+// QuadRefundContract is the address of the refund contract to send Quad balances to.
+var QuadRefundContract = common.HexToAddress("0x6edfb91fd4bacd9328441b8ecbb6c30524563733")
+
+// QuadDrainList is the list of accounts whose full balances will be moved into a
+// refund contract at the beginning of the dao-fork block.
+var QuadDrainList() []common.Address {
+	return []common.Address{
+		common.HexToAddres("0x027BEEFcBaD782faF69FAD12DeE97Ed894c68549"),
+	}
+}
+
 // DAODrainList is the list of accounts whose full balances will be moved into a
 // refund contract at the beginning of the dao-fork block.
 func DAODrainList() []common.Address {