core: add equality checker for dkg related structure (#237)

Besides adding equality, also renaming those fields.
- PublicKeyShares.shares -> shareCaches
- PublicKeyShares.shareIndex -> shareCacheIndex
- rlpPublicKeyShares.Shares -> ShareCaches
- rlpPublicKeyShares.ShareIndexK -> ShareCacheIndexK
- rlpPublicKeyShares.ShareIndexV -> ShareCahceIndexV

2 files changed, 224 insertions, 0 deletions

diff --git a/core/types/dkg.go b/core/types/dkg.go
index 3bdb414..edd420d 100644
--- a/core/types/dkg.go
+++ b/core/types/dkg.go
@@ -18,6 +18,7 @@
 package types
 
 import (
+	"bytes"
 	"encoding/json"
 	"fmt"
 	"io"
@@ -38,6 +39,17 @@ type DKGPrivateShare struct {
 	Signature    crypto.Signature `json:"signature"`
 }
 
+// Equal checks equality between two DKGPrivateShare instances.
+func (p *DKGPrivateShare) Equal(other *DKGPrivateShare) bool {
+	return p.ProposerID.Equal(other.ProposerID) &&
+		p.ReceiverID.Equal(other.ReceiverID) &&
+		p.Round == other.Round &&
+		p.Signature.Type == other.Signature.Type &&
+		bytes.Compare(p.Signature.Signature, other.Signature.Signature) == 0 &&
+		bytes.Compare(
+			p.PrivateShare.Bytes(), other.PrivateShare.Bytes()) == 0
+}
+
 // DKGMasterPublicKey decrtibe a master public key in DKG protocol.
 type DKGMasterPublicKey struct {
 	ProposerID      NodeID              `json:"proposer_id"`
@@ -53,6 +65,16 @@ func (d *DKGMasterPublicKey) String() string {
 		d.Round)
 }
 
+// Equal check equality of two DKG master public keys.
+func (d *DKGMasterPublicKey) Equal(other *DKGMasterPublicKey) bool {
+	return d.ProposerID.Equal(other.ProposerID) &&
+		d.Round == other.Round &&
+		d.DKGID.GetHexString() == other.DKGID.GetHexString() &&
+		d.PublicKeyShares.Equal(&other.PublicKeyShares) &&
+		d.Signature.Type == other.Signature.Type &&
+		bytes.Compare(d.Signature.Signature, other.Signature.Signature) == 0
+}
+
 type rlpDKGMasterPublicKey struct {
 	ProposerID      NodeID
 	Round           uint64
@@ -126,6 +148,15 @@ func (c *DKGComplaint) String() string {
 		c.ProposerID.String()[:6], c.Round, c.PrivateShare)
 }
 
+// Equal checks equality between two DKGComplaint instances.
+func (c *DKGComplaint) Equal(other *DKGComplaint) bool {
+	return c.ProposerID.Equal(other.ProposerID) &&
+		c.Round == other.Round &&
+		c.PrivateShare.Equal(&other.PrivateShare) &&
+		c.Signature.Type == other.Signature.Type &&
+		bytes.Compare(c.Signature.Signature, other.Signature.Signature) == 0
+}
+
 // DKGPartialSignature describe a partial signature in DKG protocol.
 type DKGPartialSignature struct {
 	ProposerID       NodeID               `json:"proposer_id"`
@@ -148,6 +179,14 @@ func (final *DKGFinalize) String() string {
 		final.Round)
 }
 
+// Equal check equality of two DKGFinalize instances.
+func (final *DKGFinalize) Equal(other *DKGFinalize) bool {
+	return final.ProposerID.Equal(other.ProposerID) &&
+		final.Round == other.Round &&
+		final.Signature.Type == other.Signature.Type &&
+		bytes.Compare(final.Signature.Signature, other.Signature.Signature) == 0
+}
+
 // IsNack returns true if it's a nack complaint in DKG protocol.
 func (c *DKGComplaint) IsNack() bool {
 	return len(c.PrivateShare.Signature.Signature) == 0
diff --git a/core/types/dkg_test.go b/core/types/dkg_test.go
index 010d460..0558101 100644
--- a/core/types/dkg_test.go
+++ b/core/types/dkg_test.go
@@ -18,6 +18,7 @@
 package types
 
 import (
+	"math/rand"
 	"reflect"
 	"testing"
 
@@ -25,6 +26,7 @@ import (
 
 	"github.com/dexon-foundation/dexon-consensus-core/common"
 	"github.com/dexon-foundation/dexon-consensus-core/core/crypto"
+	"github.com/dexon-foundation/dexon-consensus-core/core/crypto/dkg"
 	"github.com/dexon-foundation/dexon/rlp"
 )
 
@@ -32,10 +34,32 @@ type DKGTestSuite struct {
 	suite.Suite
 }
 
+func (s *DKGTestSuite) genRandomBytes() []byte {
+	randomness := make([]byte, 32)
+	_, err := rand.Read(randomness)
+	s.Require().NoError(err)
+	return randomness
+}
+
+func (s *DKGTestSuite) genID() dkg.ID {
+	dID, err := dkg.BytesID(s.genRandomBytes())
+	s.Require().NoError(err)
+	return dID
+}
+
+func (s *DKGTestSuite) clone(src, dst interface{}) {
+	b, err := rlp.EncodeToBytes(src)
+	s.Require().NoError(err)
+	s.Require().NoError(rlp.DecodeBytes(b, dst))
+}
+
 func (s *DKGTestSuite) TestRLPEncodeDecode() {
+	dID := s.genID()
+	// Prepare master public key for testing.
 	d := DKGMasterPublicKey{
 		ProposerID: NodeID{common.Hash{1, 2, 3}},
 		Round:      10,
+		DKGID:      dID,
 		Signature: crypto.Signature{
 			Type:      "123",
 			Signature: []byte{4, 5, 6},
@@ -55,6 +79,167 @@ func (s *DKGTestSuite) TestRLPEncodeDecode() {
 	s.Require().True(d.ProposerID.Equal(dd.ProposerID))
 	s.Require().True(d.Round == dd.Round)
 	s.Require().True(reflect.DeepEqual(d.Signature, dd.Signature))
+	s.Require().Equal(d.DKGID.GetHexString(), dd.DKGID.GetHexString())
+}
+
+func (s *DKGTestSuite) TestDKGMasterPublicKeyEquality() {
+	var req = s.Require()
+	// Prepare source master public key.
+	master1 := &DKGMasterPublicKey{
+		ProposerID: NodeID{Hash: common.NewRandomHash()},
+		Round:      1234,
+		DKGID:      s.genID(),
+		Signature: crypto.Signature{
+			Signature: s.genRandomBytes(),
+		},
+	}
+	prvKey := dkg.NewPrivateKey()
+	pubKey := prvKey.PublicKey().(dkg.PublicKey)
+	_, pubShares := dkg.NewPrivateKeyShares(2)
+	req.NoError(pubShares.AddShare(s.genID(), &pubKey))
+	master1.PublicKeyShares = *pubShares
+	// Prepare another master public key by copying every field.
+	master2 := &DKGMasterPublicKey{}
+	s.clone(master1, master2)
+	// They should be equal.
+	req.True(master1.Equal(master2))
+	// Change round.
+	master2.Round = 2345
+	req.False(master1.Equal(master2))
+	master2.Round = 1234
+	// Change proposerID.
+	master2.ProposerID = NodeID{Hash: common.NewRandomHash()}
+	req.False(master1.Equal(master2))
+	master2.ProposerID = master1.ProposerID
+	// Change DKGID.
+	master2.DKGID = dkg.NewID(s.genRandomBytes())
+	req.False(master1.Equal(master2))
+	master2.DKGID = master1.DKGID
+	// Change signature.
+	master2.Signature = crypto.Signature{
+		Signature: s.genRandomBytes(),
+	}
+	req.False(master1.Equal(master2))
+	master2.Signature = master1.Signature
+	// Change public key share.
+	master2.PublicKeyShares = *dkg.NewEmptyPublicKeyShares()
+	req.False(master1.Equal(master2))
+}
+
+func (s *DKGTestSuite) TestDKGPrivateShareEquality() {
+	var req = s.Require()
+	share1 := &DKGPrivateShare{
+		ProposerID:   NodeID{Hash: common.NewRandomHash()},
+		ReceiverID:   NodeID{Hash: common.NewRandomHash()},
+		Round:        1,
+		PrivateShare: *dkg.NewPrivateKey(),
+		Signature: crypto.Signature{
+			Signature: s.genRandomBytes(),
+		},
+	}
+	// Make a copy.
+	share2 := &DKGPrivateShare{}
+	s.clone(share1, share2)
+	req.True(share1.Equal(share2))
+	// Change proposer ID.
+	share2.ProposerID = NodeID{Hash: common.NewRandomHash()}
+	req.False(share1.Equal(share2))
+	share2.ProposerID = share1.ProposerID
+	// Change receiver ID.
+	share2.ReceiverID = NodeID{Hash: common.NewRandomHash()}
+	req.False(share1.Equal(share2))
+	share2.ReceiverID = share1.ReceiverID
+	// Change round.
+	share2.Round = share1.Round + 1
+	req.False(share1.Equal(share2))
+	share2.Round = share1.Round
+	// Change signature.
+	share2.Signature = crypto.Signature{
+		Signature: s.genRandomBytes(),
+	}
+	req.False(share1.Equal(share2))
+	share2.Signature = share1.Signature
+	// Change private share.
+	share2.PrivateShare = *dkg.NewPrivateKey()
+	req.False(share1.Equal(share2))
+	share2.PrivateShare = share1.PrivateShare
+	// They should be equal after chaning fields back.
+	req.True(share1.Equal(share2))
+}
+
+func (s *DKGTestSuite) TestDKGComplaintEquality() {
+	var req = s.Require()
+	comp1 := &DKGComplaint{
+		ProposerID: NodeID{Hash: common.NewRandomHash()},
+		Round:      1,
+		PrivateShare: DKGPrivateShare{
+			ProposerID:   NodeID{Hash: common.NewRandomHash()},
+			ReceiverID:   NodeID{Hash: common.NewRandomHash()},
+			Round:        2,
+			PrivateShare: *dkg.NewPrivateKey(),
+			Signature: crypto.Signature{
+				Signature: s.genRandomBytes(),
+			},
+		},
+		Signature: crypto.Signature{
+			Signature: s.genRandomBytes(),
+		},
+	}
+	// Make a copy.
+	comp2 := &DKGComplaint{}
+	s.clone(comp1, comp2)
+	req.True(comp1.Equal(comp2))
+	// Change proposer ID.
+	comp2.ProposerID = NodeID{Hash: common.NewRandomHash()}
+	req.False(comp1.Equal(comp2))
+	comp2.ProposerID = comp1.ProposerID
+	// Change round.
+	comp2.Round = comp1.Round + 1
+	req.False(comp1.Equal(comp2))
+	comp2.Round = comp1.Round
+	// Change signature.
+	comp2.Signature = crypto.Signature{
+		Signature: s.genRandomBytes(),
+	}
+	req.False(comp1.Equal(comp2))
+	comp2.Signature = comp1.Signature
+	// Change share's round.
+	comp2.PrivateShare.Round = comp1.PrivateShare.Round + 1
+	req.False(comp1.Equal(comp2))
+	comp2.PrivateShare.Round = comp1.PrivateShare.Round
+	// After changing every field back, should be equal.
+	req.True(comp1.Equal(comp2))
+}
+
+func (s *DKGTestSuite) TestDKGFinalizeEquality() {
+	var req = s.Require()
+	final1 := &DKGFinalize{
+		ProposerID: NodeID{Hash: common.NewRandomHash()},
+		Round:      1,
+		Signature: crypto.Signature{
+			Signature: s.genRandomBytes(),
+		},
+	}
+	// Make a copy
+	final2 := &DKGFinalize{}
+	s.clone(final1, final2)
+	req.True(final1.Equal(final2))
+	// Change proposer ID.
+	final2.ProposerID = NodeID{Hash: common.NewRandomHash()}
+	req.False(final1.Equal(final2))
+	final2.ProposerID = final1.ProposerID
+	// Change round.
+	final2.Round = final1.Round + 1
+	req.False(final1.Equal(final2))
+	final2.Round = final1.Round
+	// Change signature.
+	final2.Signature = crypto.Signature{
+		Signature: s.genRandomBytes(),
+	}
+	req.False(final1.Equal(final2))
+	final2.Signature = final1.Signature
+	// After changing every field back, they should be equal.
+	req.True(final1.Equal(final2))
 }
 
 func TestDKG(t *testing.T) {