parmas, crypto, core, core/vm: homestead consensus protocol changes

* change gas cost for contract creating txs
* invalidate signature with s value greater than secp256k1 N / 2
* OOG contract creation if not enough gas to store code
* new difficulty adjustment algorithm
* new DELEGATECALL op code

2 files changed, 33 insertions, 2 deletions

diff --git a/params/protocol_params.go b/params/protocol_params.go
index dcc17e05d..71c7035a4 100755
--- a/params/protocol_params.go
+++ b/params/protocol_params.go
@@ -25,9 +25,10 @@ var (
 	MaximumExtraDataSize   = big.NewInt(32)     // Maximum size extra data may be after Genesis.
 	ExpByteGas             = big.NewInt(10)     // Times ceil(log256(exponent)) for the EXP instruction.
 	SloadGas               = big.NewInt(50)     // Multiplied by the number of 32-byte words that are copied (round up) for any *COPY operation and added.
-	CallValueTransferGas   = big.NewInt(9000)   // Paid for CALL when the value transfor is non-zero.
+	CallValueTransferGas   = big.NewInt(9000)   // Paid for CALL when the value transfer is non-zero.
 	CallNewAccountGas      = big.NewInt(25000)  // Paid for CALL when the destination address didn't exist prior.
-	TxGas                  = big.NewInt(21000)  // Per transaction. NOTE: Not payable on data of calls between transactions.
+	TxGas                  = big.NewInt(21000)  // Per transaction not creating a contract. NOTE: Not payable on data of calls between transactions.
+	TxGasContractCreation  = big.NewInt(53000)  // Per transaction that creates a contract. NOTE: Not payable on data of calls between transactions.
 	TxDataZeroGas          = big.NewInt(4)      // Per byte of data attached to a transaction that equals zero. NOTE: Not payable on data of calls between transactions.
 	DifficultyBoundDivisor = big.NewInt(2048)   // The bound divisor of the difficulty, used in the update calculations.
 	QuadCoeffDiv           = big.NewInt(512)    // Divisor for the quadratic particle of the memory cost equation.
diff --git a/params/util.go b/params/util.go
new file mode 100644
index 000000000..6dda7752b
--- /dev/null
+++ b/params/util.go
@@ -0,0 +1,30 @@
+// Copyright 2015 The go-ethereum Authors
+// This file is part of the go-ethereum library.
+//
+// The go-ethereum library is free software: you can redistribute it and/or modify
+// it under the terms of the GNU Lesser General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// The go-ethereum library is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+// GNU Lesser General Public License for more details.
+//
+// You should have received a copy of the GNU Lesser General Public License
+// along with the go-ethereum library. If not, see <http://www.gnu.org/licenses/>.
+
+package params
+
+import "math/big"
+
+// TODO: set exact block number after community consensus is reached.
+var HomesteadBlock *big.Int = big.NewInt(0)
+
+func IsHomestead(blockNumber *big.Int) bool {
+	// for unit tests TODO: flip to true after homestead is live
+	if blockNumber == nil {
+		return false
+	}
+	return blockNumber.Cmp(HomesteadBlock) >= 0
+}