saving in place

pkg/contracts/key_manager.go

@@ -0,0 +1,57 @@
+package contracts
+
+import (
+	"crypto/ecdsa"
+	"encoding/hex"
+	"fmt"
+	"os"
+
+	"github.com/ethereum/go-ethereum/crypto"
+)
+
+type KeyManager struct {
+	privateKey *ecdsa.PrivateKey
+}
+
+// NewKeyManager creates a new key manager from environment
+func NewKeyManager() (*KeyManager, error) {
+	privateKeyStr := os.Getenv("PRIVATE_KEY")
+	if privateKeyStr == "" {
+		return nil, fmt.Errorf("PRIVATE_KEY environment variable not set")
+	}
+
+	// Remove 0x prefix if present
+	if len(privateKeyStr) > 2 && privateKeyStr[:2] == "0x" {
+		privateKeyStr = privateKeyStr[2:]
+	}
+
+	privateKeyBytes, err := hex.DecodeString(privateKeyStr)
+	if err != nil {
+		return nil, fmt.Errorf("invalid private key: %v", err)
+	}
+
+	privateKey, err := crypto.ToECDSA(privateKeyBytes)
+	if err != nil {
+		return nil, fmt.Errorf("invalid private key format: %v", err)
+	}
+
+	return &KeyManager{
+		privateKey: privateKey,
+	}, nil
+}
+
+// GetPrivateKey returns the private key
+func (km *KeyManager) GetPrivateKey() (*ecdsa.PrivateKey, error) {
+	if km.privateKey == nil {
+		return nil, fmt.Errorf("private key not initialized")
+	}
+	return km.privateKey, nil
+}
+
+// GetAddress returns the Ethereum address
+func (km *KeyManager) GetAddress() string {
+	if km.privateKey == nil {
+		return ""
+	}
+	return crypto.PubkeyToAddress(km.privateKey.PublicKey).Hex()
+}