fix: Prevent signing from wrong key in multisig (#12446)

crypto/keyring/output_test.go

@@ -20,7 +20,7 @@ func TestBech32KeysOutput(t *testing.T) {
 	k, err := NewMultiRecord("multisig", multisigPk)
 	require.NotNil(t, k)
 	require.NoError(t, err)
-	pubKey, err := k.GetPubKey()
+	pubKey, err := k.GetMultisigPubKey()
 	require.NoError(t, err)
 	accAddr := sdk.AccAddress(pubKey.Address())
 	expectedOutput, err := NewKeyOutput(k.Name, k.GetType(), accAddr, multisigPk)

crypto/keyring/record.go

@@ -5,6 +5,7 @@ import (
 
 	codectypes "github.com/cosmos/cosmos-sdk/codec/types"
 	"github.com/cosmos/cosmos-sdk/crypto/hd"
+	"github.com/cosmos/cosmos-sdk/crypto/keys/multisig"
 	cryptotypes "github.com/cosmos/cosmos-sdk/crypto/types"
 	"github.com/cosmos/cosmos-sdk/types"
 )
@@ -59,6 +60,16 @@ func NewMultiRecord(name string, pk cryptotypes.PubKey) (*Record, error) {
 	return newRecord(name, pk, recordMultiItem)
 }
 
+// GetMultisigPubKey fetches a public key of the multi type record
+func (k *Record) GetMultisigPubKey() (*multisig.LegacyAminoPubKey, error) {
+	pk, ok := k.PubKey.GetCachedValue().(*multisig.LegacyAminoPubKey)
+	if !ok {
+		return nil, errors.New("unable to cast any to multisig.LegacyAminoPubKey")
+	}
+
+	return pk, nil
+}
+
 // GetPubKey fetches a public key of the record
 func (k *Record) GetPubKey() (cryptotypes.PubKey, error) {
 	pk, ok := k.PubKey.GetCachedValue().(cryptotypes.PubKey)

crypto/keyring/record_test.go

@@ -10,6 +10,8 @@ import (
 	codectypes "github.com/cosmos/cosmos-sdk/codec/types"
 	"github.com/cosmos/cosmos-sdk/crypto/hd"
 	"github.com/cosmos/cosmos-sdk/crypto/keys/ed25519"
+	"github.com/cosmos/cosmos-sdk/crypto/keys/multisig"
+	"github.com/cosmos/cosmos-sdk/crypto/keys/secp256k1"
 
 	cryptotypes "github.com/cosmos/cosmos-sdk/crypto/types"
 )
@@ -17,10 +19,11 @@ import (
 type RecordTestSuite struct {
 	suite.Suite
 
-	appName string
-	cdc     codec.Codec
-	priv    cryptotypes.PrivKey
-	pub     cryptotypes.PubKey
+	appName  string
+	cdc      codec.Codec
+	priv     cryptotypes.PrivKey
+	pub      cryptotypes.PubKey
+	multiPub *multisig.LegacyAminoPubKey
 }
 
 func (s *RecordTestSuite) SetupSuite() {
@@ -28,6 +31,14 @@ func (s *RecordTestSuite) SetupSuite() {
 	s.cdc = getCodec()
 	s.priv = cryptotypes.PrivKey(ed25519.GenPrivKey())
 	s.pub = s.priv.PubKey()
+
+	multiKey := secp256k1.GenPrivKeyFromSecret([]byte("myMultiKey"))
+	pk := multisig.NewLegacyAminoPubKey(
+		1,
+		[]cryptotypes.PubKey{multiKey.PubKey()},
+	)
+	s.multiPub = pk
+
 }
 
 func (s *RecordTestSuite) TestOfflineRecordMarshaling() {
@@ -47,6 +58,32 @@ func (s *RecordTestSuite) TestOfflineRecordMarshaling() {
 	s.Require().True(s.pub.Equals(pk2))
 }
 
+func (s *RecordTestSuite) TestMultiRecordMarshaling() {
+	dir := s.T().TempDir()
+	mockIn := strings.NewReader("")
+
+	kb, err := New(s.appName, BackendTest, dir, mockIn, s.cdc)
+	s.Require().NoError(err)
+
+	k, err := NewMultiRecord("testrecord", s.multiPub)
+	s.Require().NoError(err)
+
+	ks, ok := kb.(keystore)
+	s.Require().True(ok)
+
+	bz, err := ks.cdc.Marshal(k)
+	s.Require().NoError(err)
+
+	k2, err := ks.protoUnmarshalRecord(bz)
+	s.Require().NoError(err)
+	s.Require().Equal(k.Name, k2.Name)
+	s.Require().True(k.PubKey.Equal(k2.PubKey))
+
+	pub2, err := k2.GetMultisigPubKey()
+	s.Require().NoError(err)
+	s.Require().True(s.multiPub.Equals(pub2))
+}
+
 func (s *RecordTestSuite) TestLocalRecordMarshaling() {
 	dir := s.T().TempDir()
 	mockIn := strings.NewReader("")