Bake drand public key into build params

Signed-off-by: Jakub Sztandera <kubuxu@protocol.ai>

build/params_shared.go

@@ -103,3 +103,9 @@ const BlsSignatureCacheSize = 40000
 // Limits
 
 const BlockMessageLimit = 512
+
+var DrandCoeffs = []string{
+	"a2a34cf9a6be2f66b5385caa520364f994ae7dbac08371ffaca575dfb3e04c8e149b32dc78f077322c613a151dc07440",
+	"b0c5baca062191f13099229c9a229a9946204f74fc28baa212745243553ab1f50b581b2086e24374ceb40fe34bd23ca2",
+	"a9c6449cf647e0a0ffaf1e01277e2821213c80310165990daf77610208abfa0ce56c7e40995e26aff3873c624362ca78",
+}

chain/beacon/drand/drand.go

@@ -6,6 +6,7 @@ import (
 	"sync"
 	"time"
 
+	"github.com/filecoin-project/lotus/build"
 	"github.com/filecoin-project/lotus/chain/beacon"
 	"github.com/filecoin-project/lotus/chain/types"
 	"github.com/filecoin-project/specs-actors/actors/abi"
@@ -26,6 +27,16 @@ var drandServers = []string{
 	"drand-test1.nikkolasg.xyz:5001",
 }
 
+var drandPubKey *dkey.DistPublic
+
+func init() {
+	drandPubKey = new(dkey.DistPublic)
+	err := drandPubKey.FromTOML(&dkey.DistPublicTOML{build.DrandCoeffs})
+	if err != nil {
+		panic(err)
+	}
+}
+
 type drandPeer struct {
 	addr string
 	tls  bool
@@ -79,7 +90,11 @@ func NewDrandBeacon(genesisTs, interval uint64) (*DrandBeacon, error) {
 	}
 
 	// TODO: verify these values are what we expect them to be
-	db.pubkey = kgroup.PublicKey
+	if !kgroup.PublicKey.Equal(drandPubKey) {
+		return nil, xerrors.Errorf("public key does not match")
+	}
+	// fmt.Printf("Drand Pubkey:\n%#v\n", kgroup.PublicKey.TOML()) // use to print public key
+	db.pubkey = drandPubKey
 	db.interval = kgroup.Period
 	db.drandGenTime = uint64(kgroup.GenesisTime)
 	db.filRoundTime = interval