func verify(hash common.Hash, diff *big.Int, nonce uint64) bool {
sha := sha3.NewKeccak256()
n := make([]byte, 8)
binary.PutUvarint(n, nonce)
sha.Write(n)
sha.Write(hash[:])
verification := new(big.Int).Div(common.BigPow(2, 256), diff)
res := common.BigD(sha.Sum(nil))
return res.Cmp(verification) <= 0
}
// New methods using proper ecdsa keys from the stdlib
func ToECDSA(prv []byte) *ecdsa.PrivateKey {
if len(prv) == 0 {
return nil
}
priv := new(ecdsa.PrivateKey)
priv.PublicKey.Curve = secp256k1.S256()
priv.D = common.BigD(prv)
priv.PublicKey.X, priv.PublicKey.Y = secp256k1.S256().ScalarBaseMult(prv)
return priv
}
// Seal closes the envelope by spending the requested amount of time as a proof
// of work on hashing the data.
func (self *Envelope) Seal(pow time.Duration) {
d := make([]byte, 64)
copy(d[:32], self.rlpWithoutNonce())
finish, bestBit := time.Now().Add(pow).UnixNano(), 0
for nonce := uint32(0); time.Now().UnixNano() < finish; {
for i := 0; i < 1024; i++ {
binary.BigEndian.PutUint32(d[60:], nonce)
firstBit := common.FirstBitSet(common.BigD(crypto.Sha3(d)))
if firstBit > bestBit {
self.Nonce, bestBit = nonce, firstBit
}
nonce++
}
}
}
func opMload(instr instruction, pc *uint64, env Environment, contract *Contract, memory *Memory, stack *stack) {
offset := stack.pop()
val := common.BigD(memory.Get(offset.Int64(), 32))
stack.push(val)
}