feat: add admin change funcnality to precompiled contract

test/add_admin/add_admin.go

@@ -0,0 +1,71 @@
+package main
+
+import (
+	"context"
+	"log"
+	"math/big"
+
+	"github.com/ethereum/go-ethereum/common"
+	"github.com/ethereum/go-ethereum/core/types"
+	"github.com/ethereum/go-ethereum/crypto"
+	"github.com/ethereum/go-ethereum/ethclient"
+)
+
+// This helper adds a NEW admin to the whitelist precompile.
+// It uses mode = 2 in the precompile:
+//
+//	mode = 2: add new admin (admin only, target address required)
+//
+// The caller must be an existing admin (the hard-coded admin key below).
+// The new admin in this example is node2's miner address, so node2 can also
+// manage the whitelist.
+func main() {
+	// Existing admin private key (same as used in whitelist_tx.go)
+	privHex := "PRIVATE_KEY"
+	priv, err := crypto.HexToECDSA(privHex)
+	if err != nil {
+		log.Fatalf("Failed to parse admin key: %v", err)
+	}
+	adminAddr := crypto.PubkeyToAddress(priv.PublicKey)
+
+	// New admin address to add (example: node2 miner address)
+	newAdmin := common.HexToAddress("0xab52b2c71f61cd9447a932c0cb55d1752571dab8")
+
+	client, err := ethclient.Dial("http://localhost:8545")
+	if err != nil {
+		log.Fatalf("Failed to connect to node: %v", err)
+	}
+	defer client.Close()
+
+	// Prepare input: mode=2, current admin address, new admin address
+	input := []byte{2}
+	input = append(input, adminAddr.Bytes()...)
+	input = append(input, newAdmin.Bytes()...)
+
+	nonce, err := client.PendingNonceAt(context.Background(), adminAddr)
+	if err != nil {
+		log.Fatalf("Failed to get nonce: %v", err)
+	}
+	gasPrice, err := client.SuggestGasPrice(context.Background())
+	if err != nil {
+		log.Fatalf("Failed to get gas price: %v", err)
+	}
+
+	to := common.BytesToAddress([]byte{0x01, 0x00}) // address of whitelist precompile
+	value := big.NewInt(0)
+	var gasLimit uint64 = 100000
+
+	tx := types.NewTransaction(nonce, to, value, gasLimit, gasPrice, input)
+
+	chainID := big.NewInt(1234)
+	signedTx, err := types.SignTx(tx, types.NewEIP155Signer(chainID), priv)
+	if err != nil {
+		log.Fatalf("Failed to sign tx: %v", err)
+	}
+
+	if err := client.SendTransaction(context.Background(), signedTx); err != nil {
+		log.Fatalf("Failed to send tx: %v", err)
+	}
+
+	log.Printf("Add-admin transaction sent: %s (new admin: %s)", signedTx.Hash().Hex(), newAdmin.Hex())
+}