store validator public keys (#3927)

slasher/db/BUILD.bazel

@@ -8,6 +8,7 @@ go_library(
         "indexed_attestations.go",
         "schema.go",
         "setup_db.go",
+        "validator_id_pubkey.go",
     ],
     importpath = "github.com/prysmaticlabs/prysm/slasher/db",
     visibility = ["//slasher:__subpackages__"],
@@ -29,6 +30,7 @@ go_test(
         "block_header_test.go",
         "indexed_attestations_test.go",
         "setup_db_test.go",
+        "validator_id_pubkey_test.go",
     ],
     embed = [":go_default_library"],
     deps = ["//proto/eth/v1alpha1:go_default_library"],

slasher/db/db.go

@@ -85,6 +85,7 @@ func NewKVStore(dirPath string) (*Store, error) {
 			historicIndexedAttestationsBucket,
 			historicBlockHeadersBucket,
 			indexedAttestationsIndicesBucket,
+			validatorsPublicKeysBucket,
 		)
 	}); err != nil {
 		return nil, err

slasher/db/schema.go

@@ -9,6 +9,7 @@ var (
 	historicIndexedAttestationsBucket = []byte("historic-indexed-attestations-bucket")
 	historicBlockHeadersBucket        = []byte("historic-block-headers-bucket")
 	indexedAttestationsIndicesBucket  = []byte("indexed-attestations-indices-bucket")
+	validatorsPublicKeysBucket        = []byte("validators-public-keys-bucket")
 )
 
 func encodeEpochValidatorID(epoch uint64, validatorID uint64) []byte {

slasher/db/validator_id_pubkey.go

@@ -0,0 +1,44 @@
+package db
+
+import (
+	"github.com/boltdb/bolt"
+	"github.com/pkg/errors"
+	"github.com/prysmaticlabs/prysm/shared/bytesutil"
+)
+
+// ValidatorPubKey accepts validator id and returns the corresponding pubkey.
+// Returns nil if the pubkey for this validator id does not exist.
+func (db *Store) ValidatorPubKey(validatorID uint64) ([]byte, error) {
+	var pk []byte
+	err := db.view(func(tx *bolt.Tx) error {
+		b := tx.Bucket(validatorsPublicKeysBucket)
+		pk = b.Get(bytesutil.Bytes4(validatorID))
+		return nil
+	})
+	return pk, err
+}
+
+// SavePubKey accepts a validator id and its public key  and writes it to disk.
+func (db *Store) SavePubKey(validatorID uint64, pubKey []byte) error {
+	err := db.update(func(tx *bolt.Tx) error {
+		bucket := tx.Bucket(validatorsPublicKeysBucket)
+		key := bytesutil.Bytes4(validatorID)
+		if err := bucket.Put(key, pubKey); err != nil {
+			return errors.Wrap(err, "failed to add validator public key to slasher db.")
+		}
+		return nil
+	})
+	return err
+}
+
+// DeletePubKey deletes a public key of a validator id.
+func (db *Store) DeletePubKey(validatorID uint64) error {
+	return db.update(func(tx *bolt.Tx) error {
+		bucket := tx.Bucket(validatorsPublicKeysBucket)
+		key := bytesutil.Bytes4(validatorID)
+		if err := bucket.Delete(key); err != nil {
+			return errors.Wrap(err, "failed to delete public key from validators public key bucket")
+		}
+		return bucket.Delete(key)
+	})
+}

slasher/db/validator_id_pubkey_test.go

@@ -0,0 +1,105 @@
+package db
+
+import (
+	"bytes"
+	"testing"
+)
+
+type publicKeyTestStruct struct {
+	validatorID uint64
+	pk          []byte
+}
+
+var pkTests []publicKeyTestStruct
+
+func init() {
+	pkTests = []publicKeyTestStruct{
+		{
+			validatorID: 1,
+			pk:          []byte{1, 2, 3},
+		},
+		{
+			validatorID: 2,
+			pk:          []byte{4, 5, 6},
+		},
+		{
+			validatorID: 3,
+			pk:          []byte{7, 8, 9},
+		},
+	}
+}
+
+func TestNilDBValidatorPublicKey(t *testing.T) {
+	db := SetupSlasherDB(t)
+	defer TeardownSlasherDB(t, db)
+
+	validatorID := uint64(1)
+
+	pk, err := db.ValidatorPubKey(validatorID)
+	if err != nil {
+		t.Fatal("nil ValidatorPubKey should not return error")
+	}
+	if pk != nil {
+		t.Fatal("ValidatorPubKey should return nil")
+	}
+
+}
+
+func TestSavePubKey(t *testing.T) {
+	db := SetupSlasherDB(t)
+	defer TeardownSlasherDB(t, db)
+
+	for _, tt := range pkTests {
+		err := db.SavePubKey(tt.validatorID, tt.pk)
+		if err != nil {
+			t.Fatalf("save validator public key failed: %v", err)
+		}
+
+		pk, err := db.ValidatorPubKey(tt.validatorID)
+		if err != nil {
+			t.Fatalf("failed to get validator public key: %v", err)
+		}
+
+		if pk == nil || !bytes.Equal(pk, tt.pk) {
+			t.Fatalf("get should return validator public key: %v", tt.pk)
+		}
+	}
+
+}
+
+func TestDeletePublicKey(t *testing.T) {
+	db := SetupSlasherDB(t)
+	defer TeardownSlasherDB(t, db)
+
+	for _, tt := range pkTests {
+
+		err := db.SavePubKey(tt.validatorID, tt.pk)
+		if err != nil {
+			t.Fatalf("save validator public key failed: %v", err)
+		}
+	}
+
+	for _, tt := range pkTests {
+		pk, err := db.ValidatorPubKey(tt.validatorID)
+		if err != nil {
+			t.Fatalf("failed to get validator public key: %v", err)
+		}
+
+		if pk == nil || !bytes.Equal(pk, tt.pk) {
+			t.Fatalf("get should return validator public key: %v", pk)
+		}
+		err = db.DeletePubKey(tt.validatorID)
+		if err != nil {
+			t.Fatalf("delete validator public key: %v", err)
+		}
+		pk, err = db.ValidatorPubKey(tt.validatorID)
+		if err != nil {
+			t.Fatal(err)
+		}
+		if pk != nil {
+			t.Errorf("Expected validator public key to be deleted, received: %v", pk)
+		}
+
+	}
+
+}