[🚀] add crypto pkg

pkg/crypto/aes.go

@@ -0,0 +1,71 @@
+package crypto
+
+import (
+	"crypto/aes"
+	"crypto/cipher"
+	"crypto/rand"
+	"crypto/sha256"
+	"fmt"
+	"io"
+)
+
+// AESEncryptor AES-GCM加密器
+type AESEncryptor struct {
+	key []byte
+}
+
+// NewAESEncryptor 创建AES加密器
+func NewAESEncryptor(key string) (*AESEncryptor, error) {
+	// 使用SHA256生成32字节密钥
+	hash := sha256.Sum256([]byte(key))
+	return &AESEncryptor{key: hash[:]}, nil
+}
+
+func (e *AESEncryptor) Encrypt(plaintext []byte) ([]byte, error) {
+	block, err := aes.NewCipher(e.key)
+	if err != nil {
+		return nil, fmt.Errorf("创建cipher失败: %w", err)
+	}
+
+	gcm, err := cipher.NewGCM(block)
+	if err != nil {
+		return nil, fmt.Errorf("创建GCM失败: %w", err)
+	}
+
+	nonce := make([]byte, gcm.NonceSize())
+	if _, err := io.ReadFull(rand.Reader, nonce); err != nil {
+		return nil, fmt.Errorf("生成nonce失败: %w", err)
+	}
+
+	ciphertext := gcm.Seal(nonce, nonce, plaintext, nil)
+	return ciphertext, nil
+}
+
+func (e *AESEncryptor) Decrypt(ciphertext []byte) ([]byte, error) {
+	block, err := aes.NewCipher(e.key)
+	if err != nil {
+		return nil, fmt.Errorf("创建cipher失败: %w", err)
+	}
+
+	gcm, err := cipher.NewGCM(block)
+	if err != nil {
+		return nil, fmt.Errorf("创建GCM失败: %w", err)
+	}
+
+	nonceSize := gcm.NonceSize()
+	if len(ciphertext) < nonceSize {
+		return nil, fmt.Errorf("密文长度不足")
+	}
+
+	nonce, ciphertext := ciphertext[:nonceSize], ciphertext[nonceSize:]
+	plaintext, err := gcm.Open(nil, nonce, ciphertext, nil)
+	if err != nil {
+		return nil, fmt.Errorf("解密失败: %w", err)
+	}
+
+	return plaintext, nil
+}
+
+func (e *AESEncryptor) Name() string {
+	return "AES-GCM-256"
+}