test, cmd/evm, core, core/vm: illegal code hash implementation

This implements a generic approach to enabling soft forks by allowing
anyone to put in hashes of contracts that should not be interacted from.
This will help "The DAO" in their endevour to stop any whithdrawals from
any DAO contract by convincing the mining community to accept their code
hash.

1 files changed, 21 insertions, 3 deletions

diff --git a/core/state_processor.go b/core/state_processor.go
index 95b3057bb..55c1301eb 100644
--- a/core/state_processor.go
+++ b/core/state_processor.go
@@ -17,8 +17,10 @@
 package core
 
 import (
+	"errors"
 	"math/big"
 
+	"github.com/ethereum/go-ethereum/common"
 	"github.com/ethereum/go-ethereum/core/state"
 	"github.com/ethereum/go-ethereum/core/types"
 	"github.com/ethereum/go-ethereum/core/vm"
@@ -28,8 +30,15 @@ import (
 )
 
 var (
-	big8  = big.NewInt(8)
-	big32 = big.NewInt(32)
+	big8               = big.NewInt(8)
+	big32              = big.NewInt(32)
+	illegalCodeHashErr = errors.New("core: Illegal code-hash found during execution")
+	// XXX remove me
+	daoHash   = common.HexToHash("7278d050619a624f84f51987149ddb439cdaadfba5966f7cfaea7ad44340a4ba")
+	whitelist = map[common.Address]bool{
+		common.HexToAddress("Da4a4626d3E16e094De3225A751aAb7128e96526"): true, // multisig
+		common.HexToAddress("2ba9D006C1D72E67A70b5526Fc6b4b0C0fd6D334"): true, // attack contract
+	}
 )
 
 // StateProcessor is a basic Processor, which takes care of transitioning
@@ -86,11 +95,20 @@ func (p *StateProcessor) Process(block *types.Block, statedb *state.StateDB, cfg
 // ApplyTransactions returns the generated receipts and vm logs during the
 // execution of the state transition phase.
 func ApplyTransaction(config *ChainConfig, bc *BlockChain, gp *GasPool, statedb *state.StateDB, header *types.Header, tx *types.Transaction, usedGas *big.Int, cfg vm.Config) (*types.Receipt, vm.Logs, *big.Int, error) {
-	_, gas, err := ApplyMessage(NewEnv(statedb, config, bc, tx, header, cfg), tx, gp)
+	env := NewEnv(statedb, config, bc, tx, header, cfg)
+	_, gas, err := ApplyMessage(env, tx, gp)
 	if err != nil {
 		return nil, nil, nil, err
 	}
 
+	for _, codeHash := range env.CodeHashes {
+		_, illegalHash := IllegalCodeHashes[codeHash]
+		to := tx.To()
+		if illegalHash && to != nil && !whitelist[*to] {
+			return nil, nil, nil, illegalCodeHashErr
+		}
+	}
+
 	// Update the state with pending changes
 	usedGas.Add(usedGas, gas)
 	receipt := types.NewReceipt(statedb.IntermediateRoot().Bytes(), usedGas)