node/admin: check address lengths and fix typo in governance handler

node/pkg/adminrpc/adminserver.go

@@ -604,6 +604,9 @@ func solanaCallToVaa(solanaCall *nodev1.SolanaCall, timestamp time.Time, guardia
 	if err != nil {
 		return nil, fmt.Errorf("failed to decode base58 governance contract address: %w", err)
 	}
+	if len(address) != 32 {
+		return nil, errors.New("invalid governance contract address length (expected 32 bytes)")
+	}
 
 	var governanceContract [32]byte
 	copy(governanceContract[:], address)

sdk/vaa/payloads.go

@@ -4,6 +4,7 @@ import (
 	"bytes"
 	"encoding/binary"
 	"fmt"
+	"math"
 
 	"github.com/ethereum/go-ethereum/common"
 	"github.com/holiman/uint256"
@@ -427,11 +428,31 @@ func (r BodyWormholeRelayerSetDefaultDeliveryProvider) Serialize() []byte {
 	return serializeBridgeGovernanceVaa(WormholeRelayerModuleStr, WormholeRelayerSetDefaultDeliveryProvider, r.ChainID, payload.Bytes())
 }
 
+func allZero(b []byte) bool {
+	for _, v := range b {
+		if v != 0 {
+			return false
+		}
+	}
+	return true
+}
+
 func (r BodyGeneralPurposeGovernanceEvm) Serialize() []byte {
 	payload := &bytes.Buffer{}
-	payload.Write(r.GovernanceContract[:])
-	payload.Write(r.TargetContract[:])
+	if !allZero(r.GovernanceContract[0:12]) {
+		panic("governance contract address must be 0-padded")
+	}
+
+	if !allZero(r.TargetContract[0:12]) {
+		panic("target contract address must be 0-padded")
+	}
+
+	payload.Write(r.GovernanceContract[12:])
+	payload.Write(r.TargetContract[12:])
 	// write payload len as uint16
+	if len(r.Payload) > math.MaxUint16 {
+		panic("payload too long")
+	}
 	MustWrite(payload, binary.BigEndian, uint16(len(r.Payload)))
 	payload.Write(r.Payload)
 	return serializeBridgeGovernanceVaa(GeneralPurposeGovernanceModuleStr, GovernanceAction(1), r.ChainID, payload.Bytes())
@@ -440,7 +461,7 @@ func (r BodyGeneralPurposeGovernanceEvm) Serialize() []byte {
 func (r BodyGeneralPurposeGovernanceSolana) Serialize() []byte {
 	payload := &bytes.Buffer{}
 	payload.Write(r.GovernanceContract[:])
-	// NOTE: unlike in EVM, we don't write the payload here, because we're using
+	// NOTE: unlike in EVM, we don't write the payload length here, because we're using
 	// a custom instruction encoding (there is no standard encoding like evm ABI
 	// encoding), generated by an external tool. That tool length-prefixes all
 	// the relevant dynamic fields.