feat: Add error handling for cryptographic operations

ethereum/ethereum.go

@@ -8,6 +8,15 @@ import (
 	"github.com/decred/dcrd/dcrec/secp256k1/v4"
 	"github.com/ethereum/go-ethereum/common"
 	"github.com/ethereum/go-ethereum/crypto"
+	"errors"
+	"fmt"
+)
+
+var (
+	ErrInvalidPrivateKey = errors.New("недопустимый закрытый ключ")
+	ErrInvalidPublicKey  = errors.New("недопустимый открытый ключ")
+	ErrInvalidSignature  = errors.New("недопустимая подпись")
+	ErrInvalidAddress    = errors.New("недопустимый адрес Ethereum")
 )
 
 func PublicKeyToAddress(publicKey []byte) common.Address {
@@ -19,3 +28,52 @@ func PublicKeyToAddress(publicKey []byte) common.Address {
 func AddressFromPrivateKey(privKey *secp256k1.PrivateKey) common.Address {
 	return PublicKeyToAddress(privKey.PubKey().SerializeUncompressed())
 }
+
+func GenerateKey() (*ecdsa.PrivateKey, error) {
+	privateKey, err := crypto.GenerateKey()
+	if err != nil {
+		return nil, fmt.Errorf("не удалось сгенерировать ключ: %w", err)
+	}
+
+	return privateKey, nil
+}
+
+func PublicKeyToAddress(pub *ecdsa.PublicKey) (common.Address, error) {
+	if pub == nil {
+		return common.Address{}, ErrInvalidPublicKey
+	}
+
+	address := crypto.PubkeyToAddress(*pub)
+	return address, nil
+}
+
+func VerifySignature(pubKey *ecdsa.PublicKey, message, signature []byte) error {
+	if pubKey == nil {
+		return ErrInvalidPublicKey
+	}
+
+	if len(signature) != 65 {
+		return ErrInvalidSignature
+	}
+
+	// Checking the signature
+	signatureNoRecoverID := signature[:len(signature)-1]
+	valid := crypto.VerifySignature(
+		crypto.FromECDSAPub(pubKey),
+		message,
+		signatureNoRecoverID,
+	)
+
+	if !valid {
+		return ErrInvalidSignature
+	}
+
+	return nil
+}
+
+func ValidateAddress(address common.Address) error {
+	if address == common.Address{} {
+		return ErrInvalidAddress
+	}
+	return nil
+}