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internal/wechat/decrypt/decryptor.go

@@ -0,0 +1,55 @@
+package decrypt
+
+import (
+	"context"
+	"fmt"
+	"io"
+
+	"github.com/sjzar/chatlog/internal/errors"
+	"github.com/sjzar/chatlog/internal/wechat/decrypt/darwin"
+	"github.com/sjzar/chatlog/internal/wechat/decrypt/windows"
+)
+
+// 错误定义
+var (
+	ErrInvalidVersion      = fmt.Errorf("invalid version, must be 3 or 4")
+	ErrUnsupportedPlatform = fmt.Errorf("unsupported platform")
+)
+
+// Decryptor 定义数据库解密的接口
+type Decryptor interface {
+	// Decrypt 解密数据库
+	Decrypt(ctx context.Context, dbfile string, key string, output io.Writer) error
+
+	// Validate 验证密钥是否有效
+	Validate(page1 []byte, key []byte) bool
+
+	// GetPageSize 返回页面大小
+	GetPageSize() int
+
+	// GetReserve 返回保留字节数
+	GetReserve() int
+
+	// GetHMACSize 返回HMAC大小
+	GetHMACSize() int
+
+	// GetVersion 返回解密器版本
+	GetVersion() string
+}
+
+// NewDecryptor 创建一个新的解密器
+func NewDecryptor(platform string, version int) (Decryptor, error) {
+	// 根据平台返回对应的实现
+	switch {
+	case platform == "windows" && version == 3:
+		return windows.NewV3Decryptor(), nil
+	case platform == "windows" && version == 4:
+		return windows.NewV4Decryptor(), nil
+	case platform == "darwin" && version == 3:
+		return darwin.NewV3Decryptor(), nil
+	case platform == "darwin" && version == 4:
+		return darwin.NewV4Decryptor(), nil
+	default:
+		return nil, errors.PlatformUnsupported(platform, version)
+	}
+}