aboutsummaryrefslogtreecommitdiffstats
path: root/pow/dagger/dagger.go
blob: 9ac00044335d7f167088324ee2a051063f282ddb (plain) (blame)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
package dagger

import (
    "hash"
    "math/big"
    "math/rand"
    "time"

    "github.com/ethereum/go-ethereum/ethutil"
    "github.com/ethereum/go-ethereum/logger"
    "github.com/obscuren/sha3"
)

var powlogger = logger.NewLogger("POW")

type Dagger struct {
    hash *big.Int
    xn   *big.Int
}

var Found bool

func (dag *Dagger) Find(obj *big.Int, resChan chan int64) {
    r := rand.New(rand.NewSource(time.Now().UnixNano()))

    for i := 0; i < 1000; i++ {
        rnd := r.Int63()

        res := dag.Eval(big.NewInt(rnd))
        powlogger.Infof("rnd %v\nres %v\nobj %v\n", rnd, res, obj)
        if res.Cmp(obj) < 0 {
            // Post back result on the channel
            resChan <- rnd
            // Notify other threads we've found a valid nonce
            Found = true
        }

        // Break out if found
        if Found {
            break
        }
    }

    resChan <- 0
}

func (dag *Dagger) Search(hash, diff *big.Int) *big.Int {
    // TODO fix multi threading. Somehow it results in the wrong nonce
    amountOfRoutines := 1

    dag.hash = hash

    obj := ethutil.BigPow(2, 256)
    obj = obj.Div(obj, diff)

    Found = false
    resChan := make(chan int64, 3)
    var res int64

    for k := 0; k < amountOfRoutines; k++ {
        go dag.Find(obj, resChan)

        // Wait for each go routine to finish
    }
    for k := 0; k < amountOfRoutines; k++ {
        // Get the result from the channel. 0 = quit
        if r := <-resChan; r != 0 {
            res = r
        }
    }

    return big.NewInt(res)
}

func (dag *Dagger) Verify(hash, diff, nonce *big.Int) bool {
    dag.hash = hash

    obj := ethutil.BigPow(2, 256)
    obj = obj.Div(obj, diff)

    return dag.Eval(nonce).Cmp(obj) < 0
}

func DaggerVerify(hash, diff, nonce *big.Int) bool {
    dagger := &Dagger{}
    dagger.hash = hash

    obj := ethutil.BigPow(2, 256)
    obj = obj.Div(obj, diff)

    return dagger.Eval(nonce).Cmp(obj) < 0
}

func (dag *Dagger) Node(L uint64, i uint64) *big.Int {
    if L == i {
        return dag.hash
    }

    var m *big.Int
    if L == 9 {
        m = big.NewInt(16)
    } else {
        m = big.NewInt(3)
    }

    sha := sha3.NewKeccak256()
    sha.Reset()
    d := sha3.NewKeccak256()
    b := new(big.Int)
    ret := new(big.Int)

    for k := 0; k < int(m.Uint64()); k++ {
        d.Reset()
        d.Write(dag.hash.Bytes())
        d.Write(dag.xn.Bytes())
        d.Write(big.NewInt(int64(L)).Bytes())
        d.Write(big.NewInt(int64(i)).Bytes())
        d.Write(big.NewInt(int64(k)).Bytes())

        b.SetBytes(Sum(d))
        pk := b.Uint64() & ((1 << ((L - 1) * 3)) - 1)
        sha.Write(dag.Node(L-1, pk).Bytes())
    }

    ret.SetBytes(Sum(sha))

    return ret
}

func Sum(sha hash.Hash) []byte {
    //in := make([]byte, 32)
    return sha.Sum(nil)
}

func (dag *Dagger) Eval(N *big.Int) *big.Int {
    pow := ethutil.BigPow(2, 26)
    dag.xn = pow.Div(N, pow)

    sha := sha3.NewKeccak256()
    sha.Reset()
    ret := new(big.Int)

    for k := 0; k < 4; k++ {
        d := sha3.NewKeccak256()
        b := new(big.Int)

        d.Reset()
        d.Write(dag.hash.Bytes())
        d.Write(dag.xn.Bytes())
        d.Write(N.Bytes())
        d.Write(big.NewInt(int64(k)).Bytes())

        b.SetBytes(Sum(d))
        pk := (b.Uint64() & 0x1ffffff)

        sha.Write(dag.Node(9, pk).Bytes())
    }

    return ret.SetBytes(Sum(sha))
}