Minimum changes for fixing 1.4.0 follow capabilities. (#980)

chain/info.go

@@ -7,6 +7,8 @@ import (
 	"encoding/hex"
 	"time"
 
+	"github.com/drand/drand/common"
+
 	"github.com/drand/drand/common/scheme"
 
 	"github.com/drand/drand/key"
@@ -53,8 +55,8 @@ func (c *Info) Hash() []byte {
 	_, _ = h.Write(buff)
 	_, _ = h.Write(c.GroupHash)
 
-	// Use it only if ID is not empty. Keep backward compatibility
-	if c.ID != "" {
+	// To keep backward compatibility
+	if !common.IsDefaultBeaconID(c.ID) {
 		_, _ = h.Write([]byte(c.ID))
 	}
 

core/drand_beacon_control.go

@@ -770,7 +770,7 @@ func (bp *BeaconProcess) validateGroupTransition(oldGroup, newGroup *key.Group)
 		return errors.New("control: old and new group have different period - unsupported feature at the moment")
 	}
 
-	if oldGroup.ID != newGroup.ID {
+	if !commonutils.CompareBeaconIDs(oldGroup.ID, newGroup.ID) {
 		bp.log.Errorw("", "setup_reshare", "invalid ID in received group")
 		return errors.New("control: old and new group have different ID - unsupported feature at the moment")
 	}
@@ -1145,7 +1145,7 @@ func (bp *BeaconProcess) StartFollowChain(req *drand.StartFollowRequest, stream
 	if !bytes.Equal(info.Hash(), hash) {
 		return errors.New("invalid chain info hash")
 	}
-	if beaconID != info.ID {
+	if !commonutils.CompareBeaconIDs(beaconID, info.ID) {
 		return errors.New("invalid beacon id on chain info")
 	}
 

core/drand_daemon_helper.go

@@ -20,7 +20,7 @@ func (dd *DrandDaemon) readBeaconID(metadata *protoCommon.Metadata) (string, err
 
 		if isChainHashFound {
 			// check if rcv beacon id on request points to a different id obtained from chain hash
-			if rcvBeaconID != "" && rcvBeaconID != beaconIDByHash {
+			if !common.CompareBeaconIDs(rcvBeaconID, beaconIDByHash) {
 				return "", fmt.Errorf("invalid chain hash")
 			}
 

key/group.go

@@ -116,8 +116,8 @@ func (g *Group) Hash() []byte {
 		_, _ = h.Write(g.PublicKey.Hash())
 	}
 
-	// Use it only if ID is not empty. Keep backward compatibility
-	if g.ID != "" {
+	// To keep backward compatibility
+	if !commonutils.IsDefaultBeaconID(g.ID) {
 		_, _ = h.Write([]byte(g.ID))
 	}
 
@@ -146,7 +146,7 @@ func (g *Group) String() string {
 
 // Equal indicates if two groups are equal
 func (g *Group) Equal(g2 *Group) bool {
-	if g.ID != g2.ID {
+	if !commonutils.CompareBeaconIDs(g.ID, g2.ID) {
 		return false
 	}
 	if g.Threshold != g2.Threshold {