[scanner] 实现哈希计算策略

[config] 实现配置转换

cmd/start/start.go

@@ -4,6 +4,7 @@ import (
 	"fmt"
 	"os"
 	"sysmonitord/internal/config"
+	"sysmonitord/internal/scanner/hash"
 	"sysmonitord/internal/scanner/process"
 	"sysmonitord/pkg/logger"
 
@@ -28,7 +29,13 @@ var StartCmd = &cobra.Command{
 			zap.String("审计服务器地址", fmt.Sprintf("%s:%d", cfg.Audit.Server, cfg.Audit.Port)),
 		)
 
-		procs, err := process.ScanAllProcesses()
+		hashCfg := &hash.Config{
+			UseFastHash: cfg.Scanner.File.FastHash,
+			Threshold:   cfg.Scanner.File.FastHashSize,
+			ChunkSize:   cfg.Scanner.File.FastHashChunk,
+		}
+
+		procs, err := process.ScanAllProcesses(hashCfg)
 		if err != nil {
 			logger.Log.Error("扫描进程失败", zap.Error(err))
 			os.Exit(1)
@@ -46,6 +53,7 @@ var StartCmd = &cobra.Command{
 				zap.String("name", p.Name),
 				zap.String("path", p.Path),
 				zap.String("cmdline", p.Cmdline),
+				zap.Stringer("data", p),
 			)
 		}
 	},

config.yaml

@@ -13,3 +13,6 @@ scanner:
     exclude_paths:
       - /proc
       - /sys
+    fast_hash: true
+    fast_hash_size: 100MB
+    fast_hash_chunk: 2MB

development.md

@@ -355,7 +355,9 @@ scanner:
       - /sys/
       - /dev/
       - /tmp/
-    max_file_size: 100MB
+    fast_hash: true
+    fast_hash_size: 100MB
+    fast_hash_chunk: 2MB
     hash_algorithm: sha256
   process:
     scan_interval: 30
@@ -552,6 +554,20 @@ LimitNOFILE=65536
 WantedBy=multi-user.target
 ```
 
+### 5.5 分层抽样哈希策略
+
+针对大文件（默认 >100MB）的哈希计算，为避免I/O阻塞，采用分层抽样算法：
+
+**算法逻辑**：
+1. 读取文件头部 N 字节（默认 1MB）。
+2. 读取文件尾部 N 字节（默认 1MB）。
+3. 获取文件总大小 Size。
+4. 拼接：`Head + Tail + Size`，对拼接后的数据进行 SHA256 运算。
+
+**优势**：
+- **性能**：将 GB 级文件的哈希耗时从秒级降至毫秒级。
+- **安全性**：任何对文件内容的修改，极大概率会触碰到头部（文件头结构）或尾部（数据填充），且锁定文件大小，有效检测篡改行为。
+
 ---
 
 ## 六、数据格式规范

internal/config/config.go

@@ -3,7 +3,9 @@ package config
 import (
 	"fmt"
 	"os"
+	"sysmonitord/pkg/logger"
 
+	"go.uber.org/zap"
 	"gopkg.in/yaml.v3"
 )
 
@@ -25,6 +27,11 @@ type ScannerConfig struct {
 
 type FileScannerConfig struct {
 	ExcludePaths     []string `yaml:"exclude_paths"`
+	FastHash         bool     `yaml:"fast_hash"`
+	FastHashSizeRaw  string   `yaml:"fast_hash_size"`
+	FastHashChunkRaw string   `yaml:"fast_hash_chunk"`
+	FastHashSize     int64
+	FastHashChunk    int64
 }
 
 func LoadConfig(path string) (*Config, error) {
@@ -37,5 +44,23 @@ func LoadConfig(path string) (*Config, error) {
 	if err := yaml.Unmarshal(data, &cfg); err != nil {
 		return nil, fmt.Errorf("无法解析配置文件： %w", err)
 	}
+
+	// 解析 FastHashSize
+	cfg.Scanner.File.FastHashSize, err = ParseSize(cfg.Scanner.File.FastHashSizeRaw)
+	if err != nil {
+		return nil, fmt.Errorf("解析 fast_hash_size 失败: %w", err)
+	}
+
+	// 解析 FastHashChunk
+	cfg.Scanner.File.FastHashChunk, err = ParseSize(cfg.Scanner.File.FastHashChunkRaw)
+	if err != nil {
+		return nil, fmt.Errorf("解析 fast_hash_chunk 失败: %w", err)
+	}
+
+	logger.Log.Debug("配置加载完成",
+		zap.Int64("fast_hash_size", cfg.Scanner.File.FastHashSize),
+		zap.Int64("fast_hash_chunk", cfg.Scanner.File.FastHashChunk),
+	)
+
 	return &cfg, nil
 }

internal/config/utils.go

@@ -0,0 +1,46 @@
+package config
+
+import (
+	"fmt"
+	"regexp"
+	"strconv"
+	"strings"
+)
+
+func ParseSize(sizeStr string) (int64, error) {
+	sizeStr = strings.TrimSpace(sizeStr)
+	if sizeStr == "" {
+		return 0, nil
+	}
+
+	// 正则匹配：数字 + 单位
+	re := regexp.MustCompile(`(?i)^(\d+)\s*([KMGT]?B?)$`)
+	matches := re.FindStringSubmatch(sizeStr)
+	if len(matches) != 3 {
+		return 0, fmt.Errorf("无效的大小格式: %s", sizeStr)
+	}
+
+	value, err := strconv.ParseInt(matches[1], 10, 64)
+	if err != nil {
+		return 0, err
+	}
+
+	unit := strings.ToUpper(matches[2])
+	var multiplier int64 = 1
+	switch unit {
+	case "B", "":
+		multiplier = 1
+	case "KB", "K":
+		multiplier = 1024
+	case "MB", "M":
+		multiplier = 1024 * 1024
+	case "GB", "G":
+		multiplier = 1024 * 1024 * 1024
+	case "TB", "T":
+		multiplier = 1024 * 1024 * 1024 * 1024
+	default:
+		return 0, fmt.Errorf("未知的单位: %s", unit)
+	}
+
+	return value * multiplier, nil
+}

internal/scanner/hash/hash.go

@@ -0,0 +1,92 @@
+package hash
+
+import (
+	"crypto/sha256"
+	"encoding/binary"
+	"encoding/hex"
+	"io"
+	"os"
+	"sysmonitord/pkg/logger"
+
+	"go.uber.org/zap"
+)
+
+type Config struct {
+	UseFastHash bool
+	Threshold   int64
+	ChunkSize   int64
+}
+
+func SHA256(filePath string, cfg *Config) (string, error) {
+	info, err := os.Stat(filePath)
+	if err != nil {
+		logger.Log.Warn("[hash]获取文件信息失败", zap.String("path", filePath), zap.Error(err))
+		return "", err
+	}
+
+	fileSize := info.Size()
+
+	if cfg != nil && cfg.UseFastHash && fileSize > cfg.Threshold {
+		logger.Log.Debug("[hash] 分层哈希...",
+			zap.String("path", filePath),
+			zap.Int64("fileSize", fileSize),
+		)
+		return calculateFastHash(filePath, fileSize, cfg.ChunkSize)
+	}
+
+	return calculateFullHash(filePath)
+}
+
+func calculateFullHash(filePath string) (string, error) {
+	file, err := os.Open(filePath)
+	if err != nil {
+		logger.Log.Warn("[scanner]打开文件失败", zap.String("path", filePath), zap.Error(err))
+		return "", err
+	}
+	defer file.Close()
+
+	hasher := sha256.New()
+	if _, err := io.Copy(hasher, file); err != nil {
+		logger.Log.Error("[scanner]读取文件失败", zap.String("path", filePath), zap.Error(err))
+		return "", err
+	}
+
+	hashBytes := hasher.Sum(nil)
+	hashString := hex.EncodeToString(hashBytes)
+	return hashString, nil
+}
+
+func calculateFastHash(filePath string, fileSize int64, chunkSize int64) (string, error) {
+	file, err := os.Open(filePath)
+	if err != nil {
+		logger.Log.Warn("[scanner]打开文件失败", zap.String("path", filePath), zap.Error(err))
+		return "", err
+	}
+	defer file.Close()
+
+	hasher := sha256.New()
+
+	if _, err := io.CopyN(hasher, file, chunkSize); err != nil {
+		if err != io.EOF {
+			return "", err
+		}
+	}
+
+	tailOffset := fileSize - chunkSize
+	if tailOffset < 0 {
+		tailOffset = 0
+	}
+
+	if _, err := file.Seek(tailOffset, io.SeekStart); err != nil {
+		return "", err
+	}
+
+	if _, err := io.CopyN(hasher, file, chunkSize); err != nil {
+		return "", err
+	}
+
+	if err := binary.Write(hasher, binary.BigEndian, fileSize); err != nil {
+		return "", err
+	}
+	return hex.EncodeToString(hasher.Sum(nil)), nil
+}

internal/scanner/process/process.go

@@ -2,6 +2,8 @@ package process
 
 import (
 	"fmt"
+	"os"
+	"sysmonitord/internal/scanner/hash"
 	"sysmonitord/pkg/logger"
 
 	"github.com/shirou/gopsutil/v3/process"
@@ -13,9 +15,10 @@ type ProcessInfo struct {
 	Name     string `json:"name"`
 	Path     string `json:"path"`
 	Cmdline  string `json:"cmdline"`
+	FileHash string `json:"file_hash"`
 }
 
-func ScanAllProcesses() ([]ProcessInfo, error) {
+func ScanAllProcesses(hashCfg *hash.Config) ([]ProcessInfo, error) {
 	logger.Log.Info("[scan]正在扫描系统中的所有进程...")
 
 	pids, err := process.Pids()
@@ -52,6 +55,18 @@ func ScanAllProcesses() ([]ProcessInfo, error) {
 			Path:    exePath,
 			Cmdline: cmdline,
 		}
+
+		if exePath != "" {
+			if _, err := os.Stat(exePath); err == nil {
+				fileHash, err := hash.SHA256(exePath, hashCfg)
+				if err == nil {
+					info.FileHash = fileHash
+				} else {
+					logger.Log.Warn("[scan]计算文件哈希失败", zap.String("path", exePath), zap.Error(err))
+				}
+			}
+		}
+
 		processList = append(processList, info)
 	}
 
@@ -60,7 +75,5 @@ func ScanAllProcesses() ([]ProcessInfo, error) {
 }
 
 func (p ProcessInfo) String() string {
-	return fmt.Sprintf("%s:%s:%d", p.Name, p.Path, p.PID)
+	return fmt.Sprintf("%s:%s:%s", p.Name, p.Path, p.FileHash)
-
-	// Todo: 哈希计算
 }