move siphash into internal/crypto

Author: nottug

internal/crypto/siphash.go

@@ -0,0 +1,55 @@
+package crypto
+
+type SipHasher struct {
+	v0 uint64
+	v1 uint64
+	v2 uint64
+	v3 uint64
+}
+
+func NewSipHasher(v0, v1, v2, v3 uint64) *SipHasher {
+	hasher := &SipHasher{
+		v0: v0,
+		v1: v1,
+		v2: v2,
+		v3: v3,
+	}
+
+	return hasher
+}
+
+func (h *SipHasher) XorLanes() uint64 {
+	return h.v0 ^ h.v1 ^ h.v2 ^ h.v3
+}
+
+func (h *SipHasher) SipRound() {
+	h.v0 += h.v1
+	h.v1 = h.v1<<13 | h.v1>>51
+	h.v1 ^= h.v0
+	h.v0 = h.v0<<32 | h.v0>>32
+
+	h.v2 += h.v3
+	h.v3 = h.v3<<16 | h.v3>>48
+	h.v3 ^= h.v2
+
+	h.v0 += h.v3
+	h.v3 = h.v3<<21 | h.v3>>43
+	h.v3 ^= h.v0
+
+	h.v2 += h.v1
+	h.v1 = h.v1<<17 | h.v1>>47
+	h.v1 ^= h.v2
+	h.v2 = h.v2<<32 | h.v2>>32
+}
+
+func (h *SipHasher) Hash24(nonce uint64) {
+	h.v3 ^= nonce
+	h.SipRound()
+	h.SipRound()
+	h.v0 ^= nonce
+	h.v2 ^= 0xff
+	h.SipRound()
+	h.SipRound()
+	h.SipRound()
+	h.SipRound()
+}

internal/crypto/siphash_test.go

@@ -0,0 +1,59 @@
+package crypto
+
+import (
+	"testing"
+)
+
+func TestHash24(t *testing.T) {
+	tests := []struct {
+		v0     uint64
+		v1     uint64
+		v2     uint64
+		v3     uint64
+		nonce  uint64
+		result uint64
+	}{
+		{
+			v0:     1,
+			v1:     2,
+			v2:     3,
+			v3:     4,
+			nonce:  10,
+			result: 928382149599306901,
+		},
+		{
+			v0:     1,
+			v1:     2,
+			v2:     3,
+			v3:     4,
+			nonce:  111,
+			result: 10524991083049122233,
+		},
+		{
+			v0:     9,
+			v1:     7,
+			v2:     6,
+			v3:     7,
+			nonce:  12,
+			result: 1305683875471634734,
+		},
+		{
+			v0:     9,
+			v1:     7,
+			v2:     6,
+			v3:     7,
+			nonce:  10,
+			result: 11589833042187638814,
+		},
+	}
+
+	for i, tt := range tests {
+		hasher := NewSipHasher(tt.v0, tt.v1, tt.v2, tt.v3)
+		hasher.Hash24(tt.nonce)
+		result := hasher.XorLanes()
+
+		if result != tt.result {
+			t.Errorf("failed on %d: result mismatch: have %x, want %x", i, result, tt.result)
+		}
+	}
+}

octopus/octopus.go

@@ -90,11 +90,11 @@ func octopus(hash []byte, nonce, datasetSize uint64, lookup func(index uint32) [
 
 	warpID := nonce / powWarpSize
 	for i := 0; i < powWarpSize; i++ {
-		hasher := NewSipHasher(v0, v1, v2, v3)
-		hasher.hash24(warpID*powWarpSize + uint64(i))
+		hasher := crypto.NewSipHasher(v0, v1, v2, v3)
+		hasher.Hash24(warpID*powWarpSize + uint64(i))
 		for j := 0; j < powDataPerThread; j++ {
-			hasher.sipRound()
-			d[(j*powWarpSize + i)] = uint32((hasher.xorLanes() & math.MaxUint32) % powMod)
+			hasher.SipRound()
+			d[(j*powWarpSize + i)] = uint32((hasher.XorLanes() & math.MaxUint32) % powMod)
 		}
 	}
 
@@ -130,8 +130,6 @@ func octopus(hash []byte, nonce, datasetSize uint64, lookup func(index uint32) [
 	}
 
 	halfMix := make([]byte, nodeBytes)
-	compressBytes := make([]byte, 32)
-
 	copy(halfMix, hash)
 	binary.LittleEndian.PutUint64(halfMix[len(hash):], result)
 	halfMix = crypto.Keccak512(halfMix[:len(hash)+8])
@@ -159,9 +157,7 @@ func octopus(hash []byte, nonce, datasetSize uint64, lookup func(index uint32) [
 		}
 	}
 
-	compressWords := convutil.BytesToUint32Array(compressBytes, binary.LittleEndian)
-	// @TODO: compressWords := make([]uint32, 8)
-
+	compressWords := make([]uint32, 8)
 	for i := 0; i < 8; i++ {
 		w := i * 4
 		w2 := (8 + i) * 4
@@ -179,7 +175,7 @@ func octopus(hash []byte, nonce, datasetSize uint64, lookup func(index uint32) [
 		compressWords[i] = reduction*crypto.FnvPrime ^ reduction2
 	}
 
-	compressBytes = convutil.Uint32ArrayToBytes(compressWords, binary.LittleEndian)
+	compressBytes := convutil.Uint32ArrayToBytes(compressWords, binary.LittleEndian)
 	digest := crypto.Keccak256(append(mix[:nodeBytes], compressBytes...))
 
 	return digest