161 lines
2.9 KiB
Go
161 lines
2.9 KiB
Go
package dagger
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import (
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"hash"
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"math/big"
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"math/rand"
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"time"
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"github.com/ethereum/go-ethereum/ethutil"
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"github.com/ethereum/go-ethereum/logger"
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"github.com/obscuren/sha3"
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)
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var powlogger = logger.NewLogger("POW")
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type Dagger struct {
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hash *big.Int
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xn *big.Int
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}
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var Found bool
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func (dag *Dagger) Find(obj *big.Int, resChan chan int64) {
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r := rand.New(rand.NewSource(time.Now().UnixNano()))
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for i := 0; i < 1000; i++ {
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rnd := r.Int63()
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res := dag.Eval(big.NewInt(rnd))
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powlogger.Infof("rnd %v\nres %v\nobj %v\n", rnd, res, obj)
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if res.Cmp(obj) < 0 {
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// Post back result on the channel
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resChan <- rnd
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// Notify other threads we've found a valid nonce
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Found = true
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}
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// Break out if found
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if Found {
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break
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}
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}
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resChan <- 0
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}
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func (dag *Dagger) Search(hash, diff *big.Int) *big.Int {
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// TODO fix multi threading. Somehow it results in the wrong nonce
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amountOfRoutines := 1
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dag.hash = hash
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obj := ethutil.BigPow(2, 256)
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obj = obj.Div(obj, diff)
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Found = false
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resChan := make(chan int64, 3)
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var res int64
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for k := 0; k < amountOfRoutines; k++ {
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go dag.Find(obj, resChan)
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// Wait for each go routine to finish
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}
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for k := 0; k < amountOfRoutines; k++ {
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// Get the result from the channel. 0 = quit
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if r := <-resChan; r != 0 {
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res = r
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}
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}
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return big.NewInt(res)
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}
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func (dag *Dagger) Verify(hash, diff, nonce *big.Int) bool {
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dag.hash = hash
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obj := ethutil.BigPow(2, 256)
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obj = obj.Div(obj, diff)
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return dag.Eval(nonce).Cmp(obj) < 0
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}
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func DaggerVerify(hash, diff, nonce *big.Int) bool {
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dagger := &Dagger{}
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dagger.hash = hash
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obj := ethutil.BigPow(2, 256)
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obj = obj.Div(obj, diff)
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return dagger.Eval(nonce).Cmp(obj) < 0
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}
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func (dag *Dagger) Node(L uint64, i uint64) *big.Int {
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if L == i {
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return dag.hash
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}
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var m *big.Int
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if L == 9 {
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m = big.NewInt(16)
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} else {
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m = big.NewInt(3)
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}
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sha := sha3.NewKeccak256()
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sha.Reset()
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d := sha3.NewKeccak256()
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b := new(big.Int)
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ret := new(big.Int)
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for k := 0; k < int(m.Uint64()); k++ {
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d.Reset()
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d.Write(dag.hash.Bytes())
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d.Write(dag.xn.Bytes())
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d.Write(big.NewInt(int64(L)).Bytes())
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d.Write(big.NewInt(int64(i)).Bytes())
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d.Write(big.NewInt(int64(k)).Bytes())
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b.SetBytes(Sum(d))
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pk := b.Uint64() & ((1 << ((L - 1) * 3)) - 1)
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sha.Write(dag.Node(L-1, pk).Bytes())
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}
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ret.SetBytes(Sum(sha))
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return ret
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}
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func Sum(sha hash.Hash) []byte {
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//in := make([]byte, 32)
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return sha.Sum(nil)
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}
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func (dag *Dagger) Eval(N *big.Int) *big.Int {
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pow := ethutil.BigPow(2, 26)
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dag.xn = pow.Div(N, pow)
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sha := sha3.NewKeccak256()
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sha.Reset()
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ret := new(big.Int)
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for k := 0; k < 4; k++ {
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d := sha3.NewKeccak256()
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b := new(big.Int)
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d.Reset()
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d.Write(dag.hash.Bytes())
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d.Write(dag.xn.Bytes())
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d.Write(N.Bytes())
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d.Write(big.NewInt(int64(k)).Bytes())
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b.SetBytes(Sum(d))
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pk := (b.Uint64() & 0x1ffffff)
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sha.Write(dag.Node(9, pk).Bytes())
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}
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return ret.SetBytes(Sum(sha))
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}
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