Add files via upload

internal/handler/agent.go

@@ -539,12 +539,7 @@ func (h *AgentHandler) AgentLoop(c *gin.Context) {
 			c.JSON(http.StatusBadRequest, gin.H{"error": "未找到该 WebShell 连接"})
 			return
 		}
-		remark := conn.Remark
-		if remark == "" {
-			remark = conn.URL
-		}
-		webshellContext := fmt.Sprintf("[WebShell 助手上下文] 当前连接 ID：%s，备注：%s。可用工具（仅在该连接上操作时使用，connection_id 填 \"%s\"）：webshell_exec、webshell_file_list、webshell_file_read、webshell_file_write、record_vulnerability、list_knowledge_risk_types、search_knowledge_base。Skills 包请使用「多代理 / Eino DeepAgent」会话中的内置 `skill` 工具渐进加载。\n\n用户请求：%s",
-			conn.ID, remark, conn.ID, req.Message)
+		webshellContext := BuildWebshellAssistantContext(conn, WebshellSkillHintDefault, req.Message)
 		// WebShell 模式下如果同时指定了角色，追加角色 user_prompt（工具集仍仅限 webshell 专用工具）
 		if req.Role != "" && req.Role != "默认" && h.config.Roles != nil {
 			if role, exists := h.config.Roles[req.Role]; exists && role.Enabled && role.UserPrompt != "" {
@@ -1400,12 +1395,7 @@ func (h *AgentHandler) AgentLoopStream(c *gin.Context) {
 			sendEvent("error", "未找到该 WebShell 连接", nil)
 			return
 		}
-		remark := conn.Remark
-		if remark == "" {
-			remark = conn.URL
-		}
-		webshellContext := fmt.Sprintf("[WebShell 助手上下文] 当前连接 ID：%s，备注：%s。可用工具（仅在该连接上操作时使用，connection_id 填 \"%s\"）：webshell_exec、webshell_file_list、webshell_file_read、webshell_file_write、record_vulnerability、list_knowledge_risk_types、search_knowledge_base。Skills 包请使用「多代理 / Eino DeepAgent」会话中的内置 `skill` 工具渐进加载。\n\n用户请求：%s",
-			conn.ID, remark, conn.ID, req.Message)
+		webshellContext := BuildWebshellAssistantContext(conn, WebshellSkillHintDefault, req.Message)
 		// WebShell 模式下如果同时指定了角色，追加角色 user_prompt（工具集仍仅限 webshell 专用工具）
 		if req.Role != "" && req.Role != "默认" && h.config.Roles != nil {
 			if role, exists := h.config.Roles[req.Role]; exists && role.Enabled && role.UserPrompt != "" {

internal/handler/multi_agent_prepare.go

@@ -73,12 +73,7 @@ func (h *AgentHandler) prepareMultiAgentSession(req *ChatRequest) (*multiAgentPr
 			h.logger.Warn("WebShell AI 助手：未找到连接", zap.String("id", req.WebShellConnectionID), zap.Error(errConn))
 			return nil, fmt.Errorf("未找到该 WebShell 连接")
 		}
-		remark := conn.Remark
-		if remark == "" {
-			remark = conn.URL
-		}
-		webshellContext := fmt.Sprintf("[WebShell 助手上下文] 当前连接 ID：%s，备注：%s。可用工具（仅在该连接上操作时使用，connection_id 填 \"%s\"）：webshell_exec、webshell_file_list、webshell_file_read、webshell_file_write、record_vulnerability、list_knowledge_risk_types、search_knowledge_base。Skills 包请使用 Eino 多代理内置 `skill` 工具。\n\n用户请求：%s",
-			conn.ID, remark, conn.ID, req.Message)
+		webshellContext := BuildWebshellAssistantContext(conn, WebshellSkillHintMultiAgent, req.Message)
 		// WebShell 模式下如果同时指定了角色，追加角色 user_prompt（工具集仍仅限 webshell 专用工具）
 		if req.Role != "" && req.Role != "默认" && h.config != nil && h.config.Roles != nil {
 			if role, exists := h.config.Roles[req.Role]; exists && role.Enabled && role.UserPrompt != "" {

internal/handler/webshell.go

@@ -3,20 +3,302 @@ package handler
 import (
 	"bytes"
 	"database/sql"
+	"encoding/base64"
 	"encoding/json"
 	"io"
 	"net/http"
 	"net/url"
 	"strings"
 	"time"
+	"unicode/utf8"
 
 	"cyberstrike-ai/internal/database"
 
 	"github.com/gin-gonic/gin"
 	"github.com/google/uuid"
 	"go.uber.org/zap"
+	"golang.org/x/text/encoding/simplifiedchinese"
+	"golang.org/x/text/transform"
 )
 
+// webshellSupportedEncodings 允许的 WebShell 响应编码取值（小写，含空串代表 auto）
+// 仅暴露目前最常见的几种，其他需求可后续扩展（如 Big5、Shift_JIS 等）。
+var webshellSupportedEncodings = map[string]struct{}{
+	"":        {}, // 未配置，按 auto 处理
+	"auto":    {},
+	"utf-8":   {},
+	"utf8":    {},
+	"gbk":     {},
+	"gb18030": {},
+}
+
+// normalizeWebshellEncoding 归一化编码标识：统一为小写，未知值回退为 auto，供持久化使用
+func normalizeWebshellEncoding(enc string) string {
+	enc = strings.ToLower(strings.TrimSpace(enc))
+	if _, ok := webshellSupportedEncodings[enc]; !ok {
+		return "auto"
+	}
+	if enc == "" {
+		return "auto"
+	}
+	if enc == "utf8" {
+		return "utf-8"
+	}
+	return enc
+}
+
+// decodeWebshellOutput 把 WebShell 返回的字节按指定编码转换为合法 UTF-8 字符串。
+// 约定：
+//   - "" / "auto"：若已是合法 UTF-8 原样返回，否则依次尝试 GB18030（GBK 超集）解码。
+//   - "utf-8" / "utf8"：原样返回，非法字节交由 JSON 层按 U+FFFD 处理（保持原有行为）。
+//   - "gbk" / "gb18030"：强制按对应编码解码；失败则回退原始字节。
+//
+// 该函数对空输入直接返回空串，避免不必要的转换。
+func decodeWebshellOutput(raw []byte, encoding string) string {
+	if len(raw) == 0 {
+		return ""
+	}
+	enc := normalizeWebshellEncoding(encoding)
+	switch enc {
+	case "utf-8":
+		return string(raw)
+	case "gbk":
+		if out, _, err := transform.Bytes(simplifiedchinese.GBK.NewDecoder(), raw); err == nil {
+			return string(out)
+		}
+		return string(raw)
+	case "gb18030":
+		if out, _, err := transform.Bytes(simplifiedchinese.GB18030.NewDecoder(), raw); err == nil {
+			return string(out)
+		}
+		return string(raw)
+	default: // auto
+		if utf8.Valid(raw) {
+			return string(raw)
+		}
+		// GB18030 是 GBK 的超集，覆盖范围最广，auto 模式统一用它兜底
+		if out, _, err := transform.Bytes(simplifiedchinese.GB18030.NewDecoder(), raw); err == nil {
+			return string(out)
+		}
+		return string(raw)
+	}
+}
+
+// webshellSupportedOS 允许的 WebShell 目标操作系统（小写，空串代表 auto）
+var webshellSupportedOS = map[string]struct{}{
+	"":        {},
+	"auto":    {},
+	"linux":   {},
+	"windows": {},
+}
+
+// normalizeWebshellOS 归一化 OS 标识，未知值回退为 auto，供持久化使用
+func normalizeWebshellOS(osTag string) string {
+	osTag = strings.ToLower(strings.TrimSpace(osTag))
+	if _, ok := webshellSupportedOS[osTag]; !ok {
+		return "auto"
+	}
+	if osTag == "" {
+		return "auto"
+	}
+	return osTag
+}
+
+// resolveWebshellOS 根据连接的 os 与 shellType 推断最终目标 OS（仅返回 "linux" 或 "windows"）。
+// 规则：
+//   - 显式 linux / windows：按用户选择。
+//   - auto 或未知：asp/aspx → windows，其他 → linux。保持历史行为，平滑向后兼容。
+func resolveWebshellOS(osTag, shellType string) string {
+	osTag = strings.ToLower(strings.TrimSpace(osTag))
+	switch osTag {
+	case "linux":
+		return "linux"
+	case "windows":
+		return "windows"
+	}
+	t := strings.ToLower(strings.TrimSpace(shellType))
+	if t == "asp" || t == "aspx" {
+		return "windows"
+	}
+	return "linux"
+}
+
+// quoteCmdPath 把路径按 Windows cmd.exe 规则转义。
+// 使用双引号包裹，内部双引号转义为 ""（cmd 接受的写法）。
+func quoteCmdPath(p string) string {
+	if p == "" {
+		return "\".\""
+	}
+	return "\"" + strings.ReplaceAll(p, "\"", "\"\"") + "\""
+}
+
+// quotePsSingle 把字符串按 PowerShell 单引号字符串规则转义（内部 ' → ''）。
+// 供 PowerShell 脚本参数使用，全脚本只用单引号，外层 cmd 再用双引号包裹即可安全传递。
+func quotePsSingle(s string) string {
+	return "'" + strings.ReplaceAll(s, "'", "''") + "'"
+}
+
+// quoteShellSinglePosix 把路径按 POSIX sh 单引号规则转义（内部 ' → '\''）
+func quoteShellSinglePosix(p string) string {
+	if p == "" {
+		return "."
+	}
+	return "'" + strings.ReplaceAll(p, "'", "'\\''") + "'"
+}
+
+// quoteWebshellPath 按目标 OS 选择转义方案：Linux 用 POSIX 单引号，Windows 用 cmd 双引号
+func quoteWebshellPath(path, osTag string) string {
+	if resolveWebshellOS(osTag, "") == "windows" {
+		return quoteCmdPath(path)
+	}
+	return quoteShellSinglePosix(path)
+}
+
+// buildWindowsPowerShellWrite 构造 Windows 端把 base64 内容一次性写入目标路径的 cmd 命令。
+// 外层走 cmd.exe 的 powershell 调用，PowerShell 脚本里只用单引号字符串，避免嵌套引号陷阱。
+func buildWindowsPowerShellWrite(path, b64 string) string {
+	script := "$b=[Convert]::FromBase64String(" + quotePsSingle(b64) + ");" +
+		"[IO.File]::WriteAllBytes(" + quotePsSingle(path) + ",$b)"
+	return "powershell -NoProfile -NonInteractive -Command \"" + script + "\""
+}
+
+// buildWindowsPowerShellAppend 构造 Windows 端把 base64 内容追加写入目标路径的 cmd 命令（用于分块上传）
+func buildWindowsPowerShellAppend(path, b64 string) string {
+	script := "$b=[Convert]::FromBase64String(" + quotePsSingle(b64) + ");" +
+		"$f=[IO.File]::Open(" + quotePsSingle(path) + ",[IO.FileMode]::Append,[IO.FileAccess]::Write,[IO.FileShare]::None);" +
+		"try{$f.Write($b,0,$b.Length)}finally{$f.Close()}"
+	return "powershell -NoProfile -NonInteractive -Command \"" + script + "\""
+}
+
+// fileCommandInput 封装 buildFileCommand 的输入，避免长参数列表
+type fileCommandInput struct {
+	Action     string
+	Path       string
+	TargetPath string
+	Content    string
+	ChunkIndex int
+	OS         string
+	ShellType  string
+}
+
+// buildFileCommand 根据目标 OS 与文件操作类型生成具体的远端命令字符串。
+// 同一份实现供 HTTP 入口（FileOp）与 MCP 入口（FileOpWithConnection）共用，避免双份维护。
+// 返回值第二位是用户可见的业务错误（如 "path is required"）。
+func (h *WebShellHandler) buildFileCommand(in fileCommandInput) (string, error) {
+	targetOS := resolveWebshellOS(in.OS, in.ShellType)
+	action := strings.ToLower(strings.TrimSpace(in.Action))
+	path := strings.TrimSpace(in.Path)
+
+	switch action {
+	case "list":
+		p := path
+		if p == "" {
+			p = "."
+		}
+		if targetOS == "windows" {
+			return "dir /a " + quoteCmdPath(p), nil
+		}
+		return "ls -la " + quoteShellSinglePosix(p), nil
+
+	case "read":
+		if path == "" {
+			return "", errFileOpPathRequired
+		}
+		if targetOS == "windows" {
+			return "type " + quoteCmdPath(path), nil
+		}
+		return "cat " + quoteShellSinglePosix(path), nil
+
+	case "delete":
+		if path == "" {
+			return "", errFileOpPathRequired
+		}
+		if targetOS == "windows" {
+			return "del /q /f " + quoteCmdPath(path), nil
+		}
+		return "rm -f " + quoteShellSinglePosix(path), nil
+
+	case "mkdir":
+		if path == "" {
+			return "", errFileOpPathRequired
+		}
+		if targetOS == "windows" {
+			// cmd 的 md 默认会自动创建中间目录（等价于 Linux 的 mkdir -p）
+			return "md " + quoteCmdPath(path), nil
+		}
+		return "mkdir -p " + quoteShellSinglePosix(path), nil
+
+	case "rename":
+		oldPath := path
+		newPath := strings.TrimSpace(in.TargetPath)
+		if oldPath == "" || newPath == "" {
+			return "", errFileOpRenameNeedsBothPaths
+		}
+		if targetOS == "windows" {
+			return "move /y " + quoteCmdPath(oldPath) + " " + quoteCmdPath(newPath), nil
+		}
+		return "mv -f " + quoteShellSinglePosix(oldPath) + " " + quoteShellSinglePosix(newPath), nil
+
+	case "write":
+		if path == "" {
+			return "", errFileOpPathRequired
+		}
+		// 统一策略：先把内容 base64 编码，再用目标平台对应方式解码写回，
+		// 这样既能写入任意二进制/含引号的文本，又避免各家 shell 的转义地狱。
+		b64 := base64.StdEncoding.EncodeToString([]byte(in.Content))
+		if targetOS == "windows" {
+			return buildWindowsPowerShellWrite(path, b64), nil
+		}
+		return "echo '" + b64 + "' | base64 -d > " + quoteShellSinglePosix(path), nil
+
+	case "upload":
+		if path == "" {
+			return "", errFileOpPathRequired
+		}
+		if len(in.Content) > 512*1024 {
+			return "", errFileOpUploadTooLarge
+		}
+		if targetOS == "windows" {
+			return buildWindowsPowerShellWrite(path, in.Content), nil
+		}
+		return "echo '" + in.Content + "' | base64 -d > " + quoteShellSinglePosix(path), nil
+
+	case "upload_chunk":
+		if path == "" {
+			return "", errFileOpPathRequired
+		}
+		if targetOS == "windows" {
+			if in.ChunkIndex == 0 {
+				return buildWindowsPowerShellWrite(path, in.Content), nil
+			}
+			return buildWindowsPowerShellAppend(path, in.Content), nil
+		}
+		redir := ">>"
+		if in.ChunkIndex == 0 {
+			redir = ">"
+		}
+		return "echo '" + in.Content + "' | base64 -d " + redir + " " + quoteShellSinglePosix(path), nil
+	}
+
+	return "", errFileOpUnsupportedAction(action)
+}
+
+// 业务错误常量，便于上层统一返回用户可见提示
+var (
+	errFileOpPathRequired         = simpleError("path is required")
+	errFileOpRenameNeedsBothPaths = simpleError("path and target_path are required for rename")
+	errFileOpUploadTooLarge       = simpleError("upload content too large (max 512KB base64)")
+)
+
+func errFileOpUnsupportedAction(action string) error {
+	return simpleError("unsupported action: " + action)
+}
+
+// simpleError 是不带堆栈的轻量错误类型，供 buildFileCommand 报可预期的参数校验错误
+type simpleError string
+
+func (e simpleError) Error() string { return string(e) }
+
 // WebShellHandler 代理执行 WebShell 命令（类似冰蝎/蚁剑），避免前端跨域并统一构建请求
 type WebShellHandler struct {
 	logger *zap.Logger
@@ -44,6 +326,8 @@ type CreateConnectionRequest struct {
 	Method   string `json:"method"`
 	CmdParam string `json:"cmd_param"`
 	Remark   string `json:"remark"`
+	Encoding string `json:"encoding"`
+	OS       string `json:"os"`
 }
 
 // UpdateConnectionRequest 更新连接请求
@@ -54,6 +338,8 @@ type UpdateConnectionRequest struct {
 	Method   string `json:"method"`
 	CmdParam string `json:"cmd_param"`
 	Remark   string `json:"remark"`
+	Encoding string `json:"encoding"`
+	OS       string `json:"os"`
 }
 
 // ListConnections 列出所有 WebShell 连接（GET /api/webshell/connections）
@@ -109,6 +395,8 @@ func (h *WebShellHandler) CreateConnection(c *gin.Context) {
 		Method:    method,
 		CmdParam:  strings.TrimSpace(req.CmdParam),
 		Remark:    strings.TrimSpace(req.Remark),
+		Encoding:  normalizeWebshellEncoding(req.Encoding),
+		OS:        normalizeWebshellOS(req.OS),
 		CreatedAt: time.Now(),
 	}
 	if err := h.db.CreateWebshellConnection(conn); err != nil {
@@ -159,6 +447,8 @@ func (h *WebShellHandler) UpdateConnection(c *gin.Context) {
 		Method:   method,
 		CmdParam: strings.TrimSpace(req.CmdParam),
 		Remark:   strings.TrimSpace(req.Remark),
+		Encoding: normalizeWebshellEncoding(req.Encoding),
+		OS:       normalizeWebshellOS(req.OS),
 	}
 	if err := h.db.UpdateWebshellConnection(conn); err != nil {
 		if err == sql.ErrNoRows {
@@ -331,6 +621,8 @@ type ExecRequest struct {
 	Type     string `json:"type"`      // php, asp, aspx, jsp, custom
 	Method   string `json:"method"`    // GET 或 POST，空则默认 POST
 	CmdParam string `json:"cmd_param"` // 命令参数名，如 cmd/xxx，空则默认 cmd
+	Encoding string `json:"encoding"`  // 响应编码：auto / utf-8 / gbk / gb18030，空则 auto
+	OS       string `json:"os"`        // 目标操作系统：auto / linux / windows，当前 exec 不用它，保留字段便于未来扩展
 	Command  string `json:"command" binding:"required"`
 }
 
@@ -344,23 +636,27 @@ type ExecResponse struct {
 
 // FileOpRequest 文件操作请求
 type FileOpRequest struct {
-	URL        string `json:"url" binding:"required"`
-	Password   string `json:"password"`
-	Type       string `json:"type"`
-	Method     string `json:"method"`                    // GET 或 POST，空则默认 POST
-	CmdParam   string `json:"cmd_param"`                 // 命令参数名，如 cmd/xxx，空则默认 cmd
-	Action     string `json:"action" binding:"required"` // list, read, delete, write, mkdir, rename, upload, upload_chunk
-	Path       string `json:"path"`
-	TargetPath string `json:"target_path"` // rename 时目标路径
-	Content    string `json:"content"`     // write/upload 时使用
-	ChunkIndex int    `json:"chunk_index"` // upload_chunk 时，0 表示首块
+	URL          string `json:"url" binding:"required"`
+	Password     string `json:"password"`
+	Type         string `json:"type"`
+	Method       string `json:"method"`                    // GET 或 POST，空则默认 POST
+	CmdParam     string `json:"cmd_param"`                 // 命令参数名，如 cmd/xxx，空则默认 cmd
+	Encoding     string `json:"encoding"`                  // 响应编码：auto / utf-8 / gbk / gb18030，空则 auto
+	OS           string `json:"os"`                        // 目标操作系统：auto / linux / windows，空则按 shellType 推断
+	ConnectionID string `json:"connection_id,omitempty"`   // 可选：连接 ID；服务端探活出 OS 后会回写到此连接
+	Action       string `json:"action" binding:"required"` // list, read, delete, write, mkdir, rename, upload, upload_chunk
+	Path         string `json:"path"`
+	TargetPath   string `json:"target_path"` // rename 时目标路径
+	Content      string `json:"content"`     // write/upload 时使用
+	ChunkIndex   int    `json:"chunk_index"` // upload_chunk 时，0 表示首块
 }
 
 // FileOpResponse 文件操作响应
 type FileOpResponse struct {
-	OK     bool   `json:"ok"`
-	Output string `json:"output"`
-	Error  string `json:"error,omitempty"`
+	OK         bool   `json:"ok"`
+	Output     string `json:"output"`
+	Error      string `json:"error,omitempty"`
+	DetectedOS string `json:"detected_os,omitempty"` // 仅在 auto 模式且探活成功时返回，前端应更新本地缓存
 }
 
 func (h *WebShellHandler) Exec(c *gin.Context) {
@@ -415,7 +711,7 @@ func (h *WebShellHandler) Exec(c *gin.Context) {
 	if readErr != nil {
 		h.logger.Warn("webshell exec read body", zap.Error(readErr))
 	}
-	output := string(out)
+	output := decodeWebshellOutput(out, req.Encoding)
 	httpCode := resp.StatusCode
 
 	c.JSON(http.StatusOK, ExecResponse{
@@ -474,83 +770,32 @@ func (h *WebShellHandler) FileOp(c *gin.Context) {
 		return
 	}
 
-	// 通过执行系统命令实现文件操作（与通用一句话兼容）
-	var command string
-	shellType := strings.ToLower(strings.TrimSpace(req.Type))
-	switch req.Action {
-	case "list":
-		path := strings.TrimSpace(req.Path)
-		if path == "" {
-			path = "."
+	// 若 OS 未显式配置，先发一次探活命令，识别出真实 OS 再构造文件操作命令。
+	// 这解决了 "Windows + PHP + OS=auto" 场景下旧 fallback 错发 `ls -la` 导致目录列不出来的问题。
+	osTag := req.OS
+	detectedOS := ""
+	if normalizeWebshellOS(osTag) == "auto" {
+		if probed := probeWebshellOSViaExec(h.newHTTPExecFn(req.URL, req.Password, req.Type, req.Method, req.CmdParam, req.Encoding)); probed != "" {
+			osTag = probed
+			detectedOS = probed
+			// 若前端带了 connection_id，顺带把探活结果持久化到该连接，后续刷新零成本
+			if cid := strings.TrimSpace(req.ConnectionID); cid != "" {
+				h.persistDetectedOS(cid, probed)
+			}
 		}
-		if shellType == "asp" || shellType == "aspx" {
-			command = "dir " + h.escapePath(path)
-		} else {
-			command = "ls -la " + h.escapePath(path)
-		}
-	case "read":
-		if shellType == "asp" || shellType == "aspx" {
-			command = "type " + h.escapePath(strings.TrimSpace(req.Path))
-		} else {
-			command = "cat " + h.escapePath(strings.TrimSpace(req.Path))
-		}
-	case "delete":
-		if shellType == "asp" || shellType == "aspx" {
-			command = "del " + h.escapePath(strings.TrimSpace(req.Path))
-		} else {
-			command = "rm -f " + h.escapePath(strings.TrimSpace(req.Path))
-		}
-	case "write":
-		path := h.escapePath(strings.TrimSpace(req.Path))
-		command = "echo " + h.escapeForEcho(req.Content) + " > " + path
-	case "mkdir":
-		path := strings.TrimSpace(req.Path)
-		if path == "" {
-			c.JSON(http.StatusBadRequest, FileOpResponse{OK: false, Error: "path is required for mkdir"})
-			return
-		}
-		if shellType == "asp" || shellType == "aspx" {
-			command = "md " + h.escapePath(path)
-		} else {
-			command = "mkdir -p " + h.escapePath(path)
-		}
-	case "rename":
-		oldPath := strings.TrimSpace(req.Path)
-		newPath := strings.TrimSpace(req.TargetPath)
-		if oldPath == "" || newPath == "" {
-			c.JSON(http.StatusBadRequest, FileOpResponse{OK: false, Error: "path and target_path are required for rename"})
-			return
-		}
-		if shellType == "asp" || shellType == "aspx" {
-			command = "move /y " + h.escapePath(oldPath) + " " + h.escapePath(newPath)
-		} else {
-			command = "mv " + h.escapePath(oldPath) + " " + h.escapePath(newPath)
-		}
-	case "upload":
-		path := strings.TrimSpace(req.Path)
-		if path == "" {
-			c.JSON(http.StatusBadRequest, FileOpResponse{OK: false, Error: "path is required for upload"})
-			return
-		}
-		if len(req.Content) > 512*1024 {
-			c.JSON(http.StatusBadRequest, FileOpResponse{OK: false, Error: "upload content too large (max 512KB base64)"})
-			return
-		}
-		// base64 仅含 A-Za-z0-9+/=，用单引号包裹安全
-		command = "echo " + "'" + req.Content + "'" + " | base64 -d > " + h.escapePath(path)
-	case "upload_chunk":
-		path := strings.TrimSpace(req.Path)
-		if path == "" {
-			c.JSON(http.StatusBadRequest, FileOpResponse{OK: false, Error: "path is required for upload_chunk"})
-			return
-		}
-		redir := ">>"
-		if req.ChunkIndex == 0 {
-			redir = ">"
-		}
-		command = "echo " + "'" + req.Content + "'" + " | base64 -d " + redir + " " + h.escapePath(path)
-	default:
-		c.JSON(http.StatusBadRequest, FileOpResponse{OK: false, Error: "unsupported action: " + req.Action})
+	}
+
+	command, cmdErr := h.buildFileCommand(fileCommandInput{
+		Action:     req.Action,
+		Path:       req.Path,
+		TargetPath: req.TargetPath,
+		Content:    req.Content,
+		ChunkIndex: req.ChunkIndex,
+		OS:         osTag,
+		ShellType:  req.Type,
+	})
+	if cmdErr != nil {
+		c.JSON(http.StatusBadRequest, FileOpResponse{OK: false, Error: cmdErr.Error()})
 		return
 	}
 
@@ -585,27 +830,15 @@ func (h *WebShellHandler) FileOp(c *gin.Context) {
 	if readErr != nil {
 		h.logger.Warn("webshell fileop read body", zap.Error(readErr))
 	}
-	output := string(out)
+	output := decodeWebshellOutput(out, req.Encoding)
 
 	c.JSON(http.StatusOK, FileOpResponse{
-		OK:     resp.StatusCode == http.StatusOK,
-		Output: output,
+		OK:         resp.StatusCode == http.StatusOK,
+		Output:     output,
+		DetectedOS: detectedOS,
 	})
 }
 
-func (h *WebShellHandler) escapePath(p string) string {
-	if p == "" {
-		return "."
-	}
-	// 简单转义空格与敏感字符，避免命令注入
-	return "'" + strings.ReplaceAll(p, "'", "'\\''") + "'"
-}
-
-func (h *WebShellHandler) escapeForEcho(s string) string {
-	// 仅用于 write：base64 写入更安全，这里简单用单引号包裹
-	return "'" + strings.ReplaceAll(s, "'", "'\"'\"'") + "'"
-}
-
 // ExecWithConnection 在指定 WebShell 连接上执行命令（供 MCP/Agent 等非 HTTP 调用）
 func (h *WebShellHandler) ExecWithConnection(conn *database.WebShellConnection, command string) (output string, ok bool, errMsg string) {
 	if conn == nil {
@@ -643,7 +876,7 @@ func (h *WebShellHandler) ExecWithConnection(conn *database.WebShellConnection,
 	if readErr != nil {
 		h.logger.Warn("webshell ExecWithConnection read body", zap.Error(readErr))
 	}
-	return string(out), resp.StatusCode == http.StatusOK, ""
+	return decodeWebshellOutput(out, conn.Encoding), resp.StatusCode == http.StatusOK, ""
 }
 
 // FileOpWithConnection 在指定 WebShell 连接上执行文件操作（供 MCP/Agent 调用），支持 list / read / write
@@ -652,40 +885,38 @@ func (h *WebShellHandler) FileOpWithConnection(conn *database.WebShellConnection
 		return "", false, "connection is nil"
 	}
 	action = strings.ToLower(strings.TrimSpace(action))
-	shellType := strings.ToLower(strings.TrimSpace(conn.Type))
-	if shellType == "" {
-		shellType = "php"
-	}
-	var command string
+	// MCP 入口仅开放 list / read / write 三种动作，与工具文档的承诺保持一致
 	switch action {
-	case "list":
-		if path == "" {
-			path = "."
-		}
-		if shellType == "asp" || shellType == "aspx" {
-			command = "dir " + h.escapePath(strings.TrimSpace(path))
-		} else {
-			command = "ls -la " + h.escapePath(strings.TrimSpace(path))
-		}
-	case "read":
-		path = strings.TrimSpace(path)
-		if path == "" {
-			return "", false, "path is required for read"
-		}
-		if shellType == "asp" || shellType == "aspx" {
-			command = "type " + h.escapePath(path)
-		} else {
-			command = "cat " + h.escapePath(path)
-		}
-	case "write":
-		path = strings.TrimSpace(path)
-		if path == "" {
-			return "", false, "path is required for write"
-		}
-		command = "echo " + h.escapeForEcho(content) + " > " + h.escapePath(path)
+	case "list", "read", "write":
+		// 支持的动作
 	default:
 		return "", false, "unsupported action: " + action + " (supported: list, read, write)"
 	}
+
+	// 若连接的 OS 为 auto，先探活并持久化，避免 AI/MCP 每次都对 Windows 发 `ls -la`
+	osTag := conn.OS
+	if normalizeWebshellOS(osTag) == "auto" {
+		if probed := probeWebshellOSViaExec(func(cmd string) (string, bool) {
+			out, exOk, _ := h.ExecWithConnection(conn, cmd)
+			return out, exOk
+		}); probed != "" {
+			osTag = probed
+			conn.OS = probed // 本次请求内使用探活结果
+			h.persistDetectedOS(conn.ID, probed)
+		}
+	}
+
+	command, cmdErr := h.buildFileCommand(fileCommandInput{
+		Action:     action,
+		Path:       path,
+		TargetPath: targetPath,
+		Content:    content,
+		OS:         osTag,
+		ShellType:  conn.Type,
+	})
+	if cmdErr != nil {
+		return "", false, cmdErr.Error()
+	}
 	useGET := strings.ToUpper(strings.TrimSpace(conn.Method)) == "GET"
 	cmdParam := strings.TrimSpace(conn.CmdParam)
 	if cmdParam == "" {
@@ -714,5 +945,5 @@ func (h *WebShellHandler) FileOpWithConnection(conn *database.WebShellConnection
 	if readErr != nil {
 		h.logger.Warn("webshell FileOpWithConnection read body", zap.Error(readErr))
 	}
-	return string(out), resp.StatusCode == http.StatusOK, ""
+	return decodeWebshellOutput(out, conn.Encoding), resp.StatusCode == http.StatusOK, ""
 }

internal/handler/webshell_context.go

@@ -0,0 +1,106 @@
+package handler
+
+import (
+	"strings"
+
+	"cyberstrike-ai/internal/database"
+)
+
+// WebshellSkillHintDefault 对话页 / Eino 单代理共用的 Skills 说明，放在 webshell 上下文末尾，
+// 供 AI 选择 skill 加载入口时参考。
+const WebshellSkillHintDefault = "Skills 包请使用「多代理 / Eino DeepAgent」会话中的内置 `skill` 工具渐进加载。"
+
+// WebshellSkillHintMultiAgent 多代理 / Eino 多代理准备阶段使用的 Skills 说明
+const WebshellSkillHintMultiAgent = "Skills 包请使用 Eino 多代理内置 `skill` 工具。"
+
+// webshellAssistantToolList AI 助手在 WebShell 上下文下允许使用的工具清单（展示给模型用）。
+// 注意：此处只是展示字符串，真正的权限限制是在调用方设置的 roleTools 切片里。
+const webshellAssistantToolList = "webshell_exec、webshell_file_list、webshell_file_read、webshell_file_write、record_vulnerability、list_knowledge_risk_types、search_knowledge_base"
+
+// BuildWebshellAssistantContext 根据连接信息与用户原始消息组装 AI 助手的上下文提示词。
+// 上下文包含：连接 ID、备注、目标系统（及对应命令集建议）、响应编码、可用工具清单、Skills 加载入口、
+// 以及最终的用户请求。调用方只需要决定 skillHint 的文案（默认使用 WebshellSkillHintDefault）。
+//
+// 之所以把这段逻辑抽到共享函数里，是为了避免 agent.go / multi_agent_prepare.go 等多处复制粘贴，
+// 并确保当我们升级 OS / Encoding 文案时只需要改一处、测一处、同步生效。
+func BuildWebshellAssistantContext(conn *database.WebShellConnection, skillHint, userMsg string) string {
+	if conn == nil {
+		// 兜底：调用方已保证 conn 非 nil，这里只是防御性返回原消息
+		return userMsg
+	}
+	remark := conn.Remark
+	if remark == "" {
+		remark = conn.URL
+	}
+
+	targetOS := resolveWebshellOS(conn.OS, conn.Type) // 归一为 "linux" / "windows"
+	encoding := normalizeWebshellEncoding(conn.Encoding)
+	if skillHint == "" {
+		skillHint = WebshellSkillHintDefault
+	}
+
+	var b strings.Builder
+	b.Grow(512 + len(userMsg))
+
+	b.WriteString("[WebShell 助手上下文] 连接 ID：")
+	b.WriteString(conn.ID)
+	b.WriteString("，备注：")
+	b.WriteString(remark)
+	b.WriteByte('\n')
+
+	// 目标系统：明确告诉 AI 能用/不能用的命令集，避免它对着 Windows 发 ls/cat/rm
+	b.WriteString("- 目标系统：")
+	b.WriteString(describeTargetOSForPrompt(targetOS))
+	b.WriteByte('\n')
+
+	// 响应编码：仅在非 auto 时显式告知，auto 模式由后端自适应，不打扰模型
+	if encHint := describeEncodingForPrompt(encoding); encHint != "" {
+		b.WriteString("- 响应编码：")
+		b.WriteString(encHint)
+		b.WriteByte('\n')
+	}
+
+	// 工具清单 & connection_id 约束：保持旧有表达，AI 已熟悉
+	b.WriteString("可用工具（仅在该连接上操作时使用，connection_id 填 \"")
+	b.WriteString(conn.ID)
+	b.WriteString("\"）：")
+	b.WriteString(webshellAssistantToolList)
+	b.WriteString("。")
+	b.WriteString(skillHint)
+	b.WriteString("\n\n用户请求：")
+	b.WriteString(userMsg)
+
+	return b.String()
+}
+
+// describeTargetOSForPrompt 返回某个 OS 对应的中文描述 + 推荐命令集 + 反例，
+// 命令列表覆盖文件管理最常用的 6 类动作（查看/读/删/改名/建目录/查找），让 AI 能直接照抄。
+func describeTargetOSForPrompt(targetOS string) string {
+	switch targetOS {
+	case "windows":
+		return "Windows（推荐 cmd/PowerShell：dir /a、type、del /q /f、move /y、md、ren；" +
+			"查找文件用 `dir /s /b 过滤词` 或 PowerShell `Get-ChildItem -Recurse`；" +
+			"避免 ls / cat / rm / mv / find 等 Unix 命令，否则将返回 `不是内部或外部命令`）"
+	case "linux":
+		return "Linux/Unix（推荐 sh/bash：ls -la、cat、rm -f、mv、mkdir -p；" +
+			"查找文件用 `find /path -name '*pattern*'`；" +
+			"避免 dir、type、del、move 等 Windows 命令）"
+	default:
+		// 理论上不会走到这里，resolveWebshellOS 已经兜底
+		return "未知（请先执行 `uname || ver` 探测再决定命令集）"
+	}
+}
+
+// describeEncodingForPrompt 返回响应编码的人类可读描述；auto 返回空串以减少 token。
+func describeEncodingForPrompt(encoding string) string {
+	switch encoding {
+	case "utf-8":
+		return "UTF-8（目标原生 UTF-8，无需额外解码）"
+	case "gbk":
+		return "GBK（中文 Windows；后端已自动转码为 UTF-8 返回，若仍出现大量 \\uFFFD 替换字符说明命令失败或编码识别错误）"
+	case "gb18030":
+		return "GB18030（后端已自动转码为 UTF-8 返回）"
+	default:
+		return ""
+	}
+}

internal/handler/webshell_context_test.go

@@ -0,0 +1,170 @@
+package handler
+
+import (
+	"strings"
+	"testing"
+
+	"cyberstrike-ai/internal/database"
+)
+
+func TestBuildWebshellAssistantContext_WindowsExplicit(t *testing.T) {
+	conn := &database.WebShellConnection{
+		ID:       "ws_win01",
+		Remark:   "IIS Windows 靶机",
+		URL:      "http://example.com/shell.php",
+		Type:     "php",
+		OS:       "windows",
+		Encoding: "gbk",
+	}
+	got := BuildWebshellAssistantContext(conn, WebshellSkillHintDefault, "列出当前目录并告诉我 flag 在哪")
+
+	mustContain(t, got,
+		"[WebShell 助手上下文]",
+		"ws_win01",
+		"IIS Windows 靶机",
+		"目标系统：Windows",
+		"dir /a",
+		"move /y",
+		"避免 ls / cat / rm",
+		"响应编码：GBK",
+		"后端已自动转码为 UTF-8",
+		"connection_id 填 \"ws_win01\"",
+		"webshell_exec、webshell_file_list",
+		WebshellSkillHintDefault,
+		"用户请求：列出当前目录并告诉我 flag 在哪",
+	)
+	// Windows 场景下不应出现 Linux 命令推荐
+	mustNotContain(t, got, "推荐 sh/bash")
+}
+
+func TestBuildWebshellAssistantContext_LinuxAutoFromPHP(t *testing.T) {
+	conn := &database.WebShellConnection{
+		ID:       "ws_lnx01",
+		Remark:   "", // 测试备注为空时 fallback URL
+		URL:      "http://example.com/a.php",
+		Type:     "php",
+		OS:       "auto", // auto + php → linux
+		Encoding: "",     // auto 编码不显式提示
+	}
+	got := BuildWebshellAssistantContext(conn, WebshellSkillHintDefault, "看看 /etc/passwd")
+
+	mustContain(t, got,
+		"连接 ID：ws_lnx01",
+		"备注：http://example.com/a.php", // 备注空时 fallback URL
+		"目标系统：Linux/Unix",
+		"ls -la",
+		"mkdir -p",
+		"避免 dir、type、del、move",
+		"用户请求：看看 /etc/passwd",
+	)
+	// encoding=auto 不应出现"响应编码："这一行
+	mustNotContain(t, got, "响应编码：")
+	// Linux 场景不应出现 Windows 命令
+	mustNotContain(t, got, "推荐 cmd/PowerShell")
+}
+
+func TestBuildWebshellAssistantContext_AutoFromASPDefaultsToWindows(t *testing.T) {
+	// 保留向后兼容：旧连接没配 os，shellType=asp 时应视为 Windows
+	conn := &database.WebShellConnection{
+		ID:       "ws_asp01",
+		Remark:   "老 ASP 靶机",
+		Type:     "asp",
+		OS:       "", // 空串等同 auto
+		Encoding: "gb18030",
+	}
+	got := BuildWebshellAssistantContext(conn, WebshellSkillHintMultiAgent, "查当前用户")
+
+	mustContain(t, got,
+		"目标系统：Windows",
+		"响应编码：GB18030",
+		"后端已自动转码为 UTF-8 返回",
+		WebshellSkillHintMultiAgent,
+	)
+	// 多代理 skill 文案里没有 DeepAgent，不应混入 default 文案
+	mustNotContain(t, got, "DeepAgent")
+}
+
+func TestBuildWebshellAssistantContext_MultiAgentSkillHint(t *testing.T) {
+	conn := &database.WebShellConnection{ID: "ws_m1", Remark: "x", Type: "php", OS: "linux"}
+	got := BuildWebshellAssistantContext(conn, WebshellSkillHintMultiAgent, "hi")
+	mustContain(t, got, WebshellSkillHintMultiAgent)
+	mustNotContain(t, got, "DeepAgent")
+}
+
+func TestBuildWebshellAssistantContext_DefaultSkillHintFallback(t *testing.T) {
+	conn := &database.WebShellConnection{ID: "ws_d1", Remark: "x", Type: "php", OS: "linux"}
+	// skillHint 传空字符串时应回退到 default
+	got := BuildWebshellAssistantContext(conn, "", "hi")
+	mustContain(t, got, WebshellSkillHintDefault)
+}
+
+func TestBuildWebshellAssistantContext_UTF8EncodingIsAnnotated(t *testing.T) {
+	conn := &database.WebShellConnection{
+		ID: "ws_u1", Remark: "u", Type: "jsp", OS: "linux", Encoding: "utf-8",
+	}
+	got := BuildWebshellAssistantContext(conn, WebshellSkillHintDefault, "hi")
+	mustContain(t, got, "响应编码：UTF-8", "目标原生 UTF-8")
+}
+
+func TestBuildWebshellAssistantContext_NilConnReturnsUserMsg(t *testing.T) {
+	// 防御性：conn == nil 时不 panic，直接返回原消息
+	got := BuildWebshellAssistantContext(nil, WebshellSkillHintDefault, "just the message")
+	if got != "just the message" {
+		t.Errorf("nil conn should return userMsg as-is, got %q", got)
+	}
+}
+
+func TestDescribeTargetOSForPrompt(t *testing.T) {
+	cases := map[string][]string{
+		"windows": {"Windows", "dir /a", "move /y", "PowerShell"},
+		"linux":   {"Linux/Unix", "ls -la", "mkdir -p"},
+		"":        {"未知", "uname"}, // 防御性分支
+	}
+	for in, wants := range cases {
+		got := describeTargetOSForPrompt(in)
+		for _, w := range wants {
+			if !strings.Contains(got, w) {
+				t.Errorf("describeTargetOSForPrompt(%q) should contain %q, got: %s", in, w, got)
+			}
+		}
+	}
+}
+
+func TestDescribeEncodingForPrompt(t *testing.T) {
+	cases := map[string]string{
+		"utf-8":   "UTF-8",
+		"gbk":     "GBK",
+		"gb18030": "GB18030",
+		"auto":    "",
+		"":        "",
+	}
+	for in, want := range cases {
+		got := describeEncodingForPrompt(in)
+		if want == "" && got != "" {
+			t.Errorf("describeEncodingForPrompt(%q) should return empty string, got: %s", in, got)
+		}
+		if want != "" && !strings.Contains(got, want) {
+			t.Errorf("describeEncodingForPrompt(%q) should contain %q, got: %s", in, want, got)
+		}
+	}
+}
+
+// ---- 小工具 ----
+
+func mustContain(t *testing.T, text string, substrings ...string) {
+	t.Helper()
+	for _, s := range substrings {
+		if !strings.Contains(text, s) {
+			t.Errorf("expected text to contain %q\n--- text ---\n%s", s, text)
+		}
+	}
+}
+
+func mustNotContain(t *testing.T, text string, substrings ...string) {
+	t.Helper()
+	for _, s := range substrings {
+		if strings.Contains(text, s) {
+			t.Errorf("text should not contain %q\n--- text ---\n%s", s, text)
+		}
+	}
+}

internal/handler/webshell_encoding_test.go

@@ -0,0 +1,103 @@
+package handler
+
+import (
+	"testing"
+
+	"golang.org/x/text/encoding/simplifiedchinese"
+	"golang.org/x/text/transform"
+)
+
+// mustEncode 使用指定编码对 UTF-8 字符串做编码，得到原始字节，用于构造测试输入
+func mustEncode(t *testing.T, s string, enc string) []byte {
+	t.Helper()
+	var tr transform.Transformer
+	switch enc {
+	case "gbk":
+		tr = simplifiedchinese.GBK.NewEncoder()
+	case "gb18030":
+		tr = simplifiedchinese.GB18030.NewEncoder()
+	default:
+		t.Fatalf("unsupported test encoding: %s", enc)
+	}
+	out, _, err := transform.Bytes(tr, []byte(s))
+	if err != nil {
+		t.Fatalf("mustEncode(%s) failed: %v", enc, err)
+	}
+	return out
+}
+
+func TestNormalizeWebshellEncoding(t *testing.T) {
+	cases := map[string]string{
+		"":         "auto",
+		"   ":      "auto",
+		"auto":     "auto",
+		"AUTO":     "auto",
+		"utf-8":    "utf-8",
+		"UTF-8":    "utf-8",
+		"utf8":     "utf-8",
+		"gbk":      "gbk",
+		"GBK":      "gbk",
+		"gb18030":  "gb18030",
+		"big5":     "auto", // 未支持的回退到 auto
+		"anything": "auto",
+	}
+	for in, want := range cases {
+		if got := normalizeWebshellEncoding(in); got != want {
+			t.Errorf("normalizeWebshellEncoding(%q) = %q, want %q", in, got, want)
+		}
+	}
+}
+
+func TestDecodeWebshellOutput_AutoDetectsGBK(t *testing.T) {
+	// 模拟 Windows 中文 cmd 输出的 GBK 字节流
+	want := "用户名                        SID                                            类型"
+	raw := mustEncode(t, want, "gbk")
+
+	// auto 模式：UTF-8 校验失败后应当回退 GB18030 解码，得到原始中文
+	got := decodeWebshellOutput(raw, "auto")
+	if got != want {
+		t.Errorf("decodeWebshellOutput(auto) = %q, want %q", got, want)
+	}
+
+	// 显式 GBK 模式：同样应当正确解码
+	got = decodeWebshellOutput(raw, "gbk")
+	if got != want {
+		t.Errorf("decodeWebshellOutput(gbk) = %q, want %q", got, want)
+	}
+
+	// 显式 GB18030 模式：GBK 是 GB18030 子集，也应正确解码
+	got = decodeWebshellOutput(raw, "gb18030")
+	if got != want {
+		t.Errorf("decodeWebshellOutput(gb18030) = %q, want %q", got, want)
+	}
+}
+
+func TestDecodeWebshellOutput_PassthroughUTF8(t *testing.T) {
+	// 已经是 UTF-8 的中文字符串，各模式都应返回原串（不破坏）
+	want := "hello 世界"
+	for _, enc := range []string{"", "auto", "utf-8"} {
+		if got := decodeWebshellOutput([]byte(want), enc); got != want {
+			t.Errorf("decodeWebshellOutput(%q) passthrough = %q, want %q", enc, got, want)
+		}
+	}
+}
+
+func TestDecodeWebshellOutput_ASCIIStable(t *testing.T) {
+	// 纯 ASCII 在任何模式下都必须保持原样
+	want := "whoami\nAdministrator\n"
+	for _, enc := range []string{"", "auto", "utf-8", "gbk", "gb18030"} {
+		if got := decodeWebshellOutput([]byte(want), enc); got != want {
+			t.Errorf("decodeWebshellOutput(%q) ASCII = %q, want %q", enc, got, want)
+		}
+	}
+}
+
+func TestDecodeWebshellOutput_EmptyInput(t *testing.T) {
+	// 空输入直接返回空串，不做额外分配
+	if got := decodeWebshellOutput(nil, "gbk"); got != "" {
+		t.Errorf("decodeWebshellOutput(nil) = %q, want empty", got)
+	}
+	if got := decodeWebshellOutput([]byte{}, "auto"); got != "" {
+		t.Errorf("decodeWebshellOutput([]) = %q, want empty", got)
+	}
+}

internal/handler/webshell_os_test.go

@@ -0,0 +1,348 @@
+package handler
+
+import (
+	"encoding/base64"
+	"strings"
+	"testing"
+
+	"go.uber.org/zap"
+)
+
+func newTestWebShellHandler() *WebShellHandler {
+	return NewWebShellHandler(zap.NewNop(), nil)
+}
+
+func TestNormalizeWebshellOS(t *testing.T) {
+	cases := map[string]string{
+		"":        "auto",
+		"  ":      "auto",
+		"auto":    "auto",
+		"AUTO":    "auto",
+		"linux":   "linux",
+		"Linux":   "linux",
+		"windows": "windows",
+		"WINDOWS": "windows",
+		"macos":   "auto", // 未支持的回退 auto
+		"solaris": "auto",
+	}
+	for in, want := range cases {
+		if got := normalizeWebshellOS(in); got != want {
+			t.Errorf("normalizeWebshellOS(%q) = %q, want %q", in, got, want)
+		}
+	}
+}
+
+func TestResolveWebshellOS(t *testing.T) {
+	type testCase struct {
+		osTag     string
+		shellType string
+		want      string
+	}
+	cases := []testCase{
+		// 显式 OS：按用户选择，忽略 shellType
+		{"linux", "asp", "linux"},
+		{"windows", "php", "windows"},
+		{"LINUX", "jsp", "linux"},
+
+		// auto + 各种 shellType：asp/aspx → windows，其他 → linux
+		{"auto", "asp", "windows"},
+		{"auto", "aspx", "windows"},
+		{"auto", "ASP", "windows"},
+		{"auto", "php", "linux"},
+		{"auto", "jsp", "linux"},
+		{"auto", "custom", "linux"},
+		{"auto", "", "linux"},
+
+		// 空/未知 OS 等价 auto
+		{"", "asp", "windows"},
+		{"", "php", "linux"},
+		{"unknown", "aspx", "windows"},
+	}
+	for _, c := range cases {
+		got := resolveWebshellOS(c.osTag, c.shellType)
+		if got != c.want {
+			t.Errorf("resolveWebshellOS(%q,%q) = %q, want %q", c.osTag, c.shellType, got, c.want)
+		}
+	}
+}
+
+func TestQuoteCmdPath(t *testing.T) {
+	cases := map[string]string{
+		"":                     `"."`,
+		`C:\Windows\Temp`:      `"C:\Windows\Temp"`,
+		`C:\Program Files\a`:   `"C:\Program Files\a"`,
+		`C:\weird"name\f.txt`:  `"C:\weird""name\f.txt"`,
+		`.`:                    `"."`,
+	}
+	for in, want := range cases {
+		if got := quoteCmdPath(in); got != want {
+			t.Errorf("quoteCmdPath(%q) = %q, want %q", in, got, want)
+		}
+	}
+}
+
+func TestQuoteShellSinglePosix(t *testing.T) {
+	cases := map[string]string{
+		"":             ".",
+		"/tmp/a b":     "'/tmp/a b'",
+		"/tmp/it's.txt": `'/tmp/it'\''s.txt'`,
+	}
+	for in, want := range cases {
+		if got := quoteShellSinglePosix(in); got != want {
+			t.Errorf("quoteShellSinglePosix(%q) = %q, want %q", in, got, want)
+		}
+	}
+}
+
+// TestBuildFileCommand_LinuxBranch 覆盖 Linux 目标下每个 action 产出的命令
+func TestBuildFileCommand_LinuxBranch(t *testing.T) {
+	h := newTestWebShellHandler()
+	base := fileCommandInput{OS: "linux", ShellType: "php"}
+
+	mustContain := func(t *testing.T, cmd string, substrings ...string) {
+		t.Helper()
+		for _, s := range substrings {
+			if !strings.Contains(cmd, s) {
+				t.Errorf("expected command to contain %q, got: %s", s, cmd)
+			}
+		}
+	}
+	mustNotContain := func(t *testing.T, cmd string, substrings ...string) {
+		t.Helper()
+		for _, s := range substrings {
+			if strings.Contains(cmd, s) {
+				t.Errorf("command should not contain %q, got: %s", s, cmd)
+			}
+		}
+	}
+
+	// list with empty path defaults to '.'
+	in := base
+	in.Action = "list"
+	cmd, err := h.buildFileCommand(in)
+	if err != nil {
+		t.Fatalf("list linux: unexpected err: %v", err)
+	}
+	mustContain(t, cmd, "ls -la", "'.'")
+
+	// list with path containing spaces
+	in.Path = "/tmp/my files"
+	cmd, _ = h.buildFileCommand(in)
+	mustContain(t, cmd, "ls -la ", "'/tmp/my files'")
+
+	// read with path
+	in = base
+	in.Action = "read"
+	in.Path = "/etc/passwd"
+	cmd, _ = h.buildFileCommand(in)
+	mustContain(t, cmd, "cat ", "'/etc/passwd'")
+
+	// read without path → error
+	in.Path = ""
+	if _, err := h.buildFileCommand(in); err != errFileOpPathRequired {
+		t.Errorf("read empty path: want errFileOpPathRequired, got %v", err)
+	}
+
+	// delete
+	in = base
+	in.Action = "delete"
+	in.Path = "/tmp/a.txt"
+	cmd, _ = h.buildFileCommand(in)
+	mustContain(t, cmd, "rm -f ", "'/tmp/a.txt'")
+	mustNotContain(t, cmd, "del")
+
+	// mkdir
+	in.Action = "mkdir"
+	in.Path = "/tmp/new/sub"
+	cmd, _ = h.buildFileCommand(in)
+	mustContain(t, cmd, "mkdir -p ", "'/tmp/new/sub'")
+
+	// rename
+	in = base
+	in.Action = "rename"
+	in.Path = "/tmp/a"
+	in.TargetPath = "/tmp/b"
+	cmd, _ = h.buildFileCommand(in)
+	mustContain(t, cmd, "mv -f ", "'/tmp/a'", "'/tmp/b'")
+
+	// rename missing target → error
+	in.TargetPath = ""
+	if _, err := h.buildFileCommand(in); err != errFileOpRenameNeedsBothPaths {
+		t.Errorf("rename empty target: want errFileOpRenameNeedsBothPaths, got %v", err)
+	}
+
+	// write
+	in = base
+	in.Action = "write"
+	in.Path = "/tmp/w.txt"
+	in.Content = "hello 世界"
+	cmd, _ = h.buildFileCommand(in)
+	b64 := base64.StdEncoding.EncodeToString([]byte("hello 世界"))
+	mustContain(t, cmd, "echo '"+b64+"'", "| base64 -d", "> '/tmp/w.txt'")
+
+	// upload
+	in = base
+	in.Action = "upload"
+	in.Path = "/tmp/bin"
+	in.Content = "YWJjZA==" // base64 of "abcd"
+	cmd, _ = h.buildFileCommand(in)
+	mustContain(t, cmd, "echo 'YWJjZA=='", "| base64 -d", "> '/tmp/bin'")
+
+	// upload oversized content → error
+	in.Content = strings.Repeat("A", 513*1024)
+	if _, err := h.buildFileCommand(in); err != errFileOpUploadTooLarge {
+		t.Errorf("upload too large: want errFileOpUploadTooLarge, got %v", err)
+	}
+
+	// upload_chunk with chunk_index=0 uses single redirect
+	in = base
+	in.Action = "upload_chunk"
+	in.Path = "/tmp/bin"
+	in.Content = "YWJj"
+	in.ChunkIndex = 0
+	cmd, _ = h.buildFileCommand(in)
+	mustContain(t, cmd, "base64 -d > '/tmp/bin'")
+	mustNotContain(t, cmd, ">>")
+
+	// upload_chunk with chunk_index>0 uses append redirect
+	in.ChunkIndex = 1
+	cmd, _ = h.buildFileCommand(in)
+	mustContain(t, cmd, "base64 -d >> '/tmp/bin'")
+
+	// unsupported action
+	in = base
+	in.Action = "nope"
+	if _, err := h.buildFileCommand(in); err == nil || !strings.Contains(err.Error(), "unsupported action") {
+		t.Errorf("unknown action: want unsupported action error, got %v", err)
+	}
+}
+
+// TestBuildFileCommand_WindowsBranch 覆盖 Windows 目标下每个 action 产出的命令
+func TestBuildFileCommand_WindowsBranch(t *testing.T) {
+	h := newTestWebShellHandler()
+	base := fileCommandInput{OS: "windows", ShellType: "php"}
+
+	mustContain := func(t *testing.T, cmd string, substrings ...string) {
+		t.Helper()
+		for _, s := range substrings {
+			if !strings.Contains(cmd, s) {
+				t.Errorf("expected command to contain %q, got: %s", s, cmd)
+			}
+		}
+	}
+	mustNotContain := func(t *testing.T, cmd string, substrings ...string) {
+		t.Helper()
+		for _, s := range substrings {
+			if strings.Contains(cmd, s) {
+				t.Errorf("command should not contain %q, got: %s", s, cmd)
+			}
+		}
+	}
+
+	// list
+	in := base
+	in.Action = "list"
+	cmd, _ := h.buildFileCommand(in)
+	mustContain(t, cmd, "dir /a ", `"."`)
+	mustNotContain(t, cmd, "ls -la")
+
+	in.Path = `C:\Users\Public Docs`
+	cmd, _ = h.buildFileCommand(in)
+	mustContain(t, cmd, "dir /a ", `"C:\Users\Public Docs"`)
+
+	// read
+	in = base
+	in.Action = "read"
+	in.Path = `C:\flag.txt`
+	cmd, _ = h.buildFileCommand(in)
+	mustContain(t, cmd, "type ", `"C:\flag.txt"`)
+
+	// delete
+	in.Action = "delete"
+	cmd, _ = h.buildFileCommand(in)
+	mustContain(t, cmd, "del /q /f ", `"C:\flag.txt"`)
+	mustNotContain(t, cmd, "rm -f")
+
+	// mkdir
+	in.Action = "mkdir"
+	in.Path = `C:\a\b\c`
+	cmd, _ = h.buildFileCommand(in)
+	mustContain(t, cmd, "md ", `"C:\a\b\c"`)
+
+	// rename
+	in = base
+	in.Action = "rename"
+	in.Path = `C:\a.txt`
+	in.TargetPath = `C:\b.txt`
+	cmd, _ = h.buildFileCommand(in)
+	mustContain(t, cmd, "move /y ", `"C:\a.txt"`, `"C:\b.txt"`)
+
+	// write → PowerShell base64 one-liner
+	in = base
+	in.Action = "write"
+	in.Path = `C:\out.txt`
+	in.Content = "hello 世界"
+	cmd, _ = h.buildFileCommand(in)
+	wantB64 := base64.StdEncoding.EncodeToString([]byte("hello 世界"))
+	mustContain(t, cmd,
+		"powershell -NoProfile -NonInteractive -Command",
+		"[Convert]::FromBase64String('"+wantB64+"')",
+		"[IO.File]::WriteAllBytes('C:\\out.txt'",
+	)
+	mustNotContain(t, cmd, "echo ", "base64 -d")
+
+	// upload (chunk_index=0 equivalent) uses WriteAllBytes
+	in = base
+	in.Action = "upload"
+	in.Path = `C:\bin\f`
+	in.Content = "YWJjZA=="
+	cmd, _ = h.buildFileCommand(in)
+	mustContain(t, cmd, "WriteAllBytes('C:\\bin\\f'", "FromBase64String('YWJjZA==')")
+
+	// upload_chunk index=0 → WriteAllBytes
+	in.Action = "upload_chunk"
+	in.ChunkIndex = 0
+	cmd, _ = h.buildFileCommand(in)
+	mustContain(t, cmd, "WriteAllBytes(")
+	mustNotContain(t, cmd, "FileMode]::Append")
+
+	// upload_chunk index>0 → append (Open with Append mode)
+	in.ChunkIndex = 1
+	cmd, _ = h.buildFileCommand(in)
+	mustContain(t, cmd, "[IO.FileMode]::Append", "FromBase64String('YWJjZA==')")
+}
+
+// TestBuildFileCommand_AutoFallbackMatchesLegacyBehavior 确保 os=auto 时与旧版 shellType 判定行为完全一致
+// asp/aspx 视为 Windows（旧行为），其他视为 Linux。
+func TestBuildFileCommand_AutoFallbackMatchesLegacyBehavior(t *testing.T) {
+	h := newTestWebShellHandler()
+
+	// asp + auto → windows 命令
+	cmd, _ := h.buildFileCommand(fileCommandInput{Action: "list", OS: "auto", ShellType: "asp"})
+	if !strings.Contains(cmd, "dir /a") {
+		t.Errorf("auto + asp should use Windows cmd, got: %s", cmd)
+	}
+
+	cmd, _ = h.buildFileCommand(fileCommandInput{Action: "list", OS: "auto", ShellType: "aspx"})
+	if !strings.Contains(cmd, "dir /a") {
+		t.Errorf("auto + aspx should use Windows cmd, got: %s", cmd)
+	}
+
+	// php/jsp/custom + auto → linux 命令（与历史行为一致）
+	for _, st := range []string{"php", "jsp", "custom", ""} {
+		cmd, _ = h.buildFileCommand(fileCommandInput{Action: "list", OS: "auto", ShellType: st})
+		if !strings.Contains(cmd, "ls -la") {
+			t.Errorf("auto + %q should use Linux cmd, got: %s", st, cmd)
+		}
+	}
+
+	// 显式 OS 覆盖 shellType
+	cmd, _ = h.buildFileCommand(fileCommandInput{Action: "list", OS: "windows", ShellType: "php"})
+	if !strings.Contains(cmd, "dir /a") {
+		t.Errorf("explicit windows should override php shellType, got: %s", cmd)
+	}
+	cmd, _ = h.buildFileCommand(fileCommandInput{Action: "list", OS: "linux", ShellType: "asp"})
+	if !strings.Contains(cmd, "ls -la") {
+		t.Errorf("explicit linux should override asp shellType, got: %s", cmd)
+	}
+}

internal/handler/webshell_probe.go

@@ -0,0 +1,127 @@
+package handler
+
+import (
+	"bytes"
+	"io"
+	"net/http"
+	"strings"
+
+	"go.uber.org/zap"
+)
+
+// webshellOSProbeCommand 探活命令：利用 Windows cmd 与 POSIX shell 对 `%OS%` 展开差异进行判定。
+//   - Windows cmd：`%OS%` 被展开为 `Windows_NT`，回显 `:OSPROBE_Windows_NT:END`
+//   - POSIX sh/bash：`%OS%` 不是变量语法，作为字面量原样保留，回显 `:OSPROBE_%OS%:END`
+//
+// 一条命令即可得到明确的、互斥的信号，避免探活成本（相比发两次命令）。
+// 冒号包裹是为了避免部分 shell 输出多余空白/BOM 时字符串匹配失效。
+const webshellOSProbeCommand = "echo :OSPROBE_%OS%:END"
+
+// probeWebshellOSViaExec 通过一次命令执行的回显推断目标操作系统。
+//
+// 返回值：
+//   - "windows" / "linux"：识别成功
+//   - ""：无法判定（调用方应保留既有 fallback 逻辑）
+//
+// 入参 execFn 是一个"发命令并拿到回显"的闭包；让 HTTP 入口和 MCP 入口可以共用同一套探活逻辑
+// 而不必关心底层是如何发包的。
+func probeWebshellOSViaExec(execFn func(cmd string) (output string, ok bool)) string {
+	if execFn == nil {
+		return ""
+	}
+	out, ok := execFn(webshellOSProbeCommand)
+	if !ok {
+		return ""
+	}
+	return classifyWebshellOSProbeOutput(out)
+}
+
+// classifyWebshellOSProbeOutput 纯函数：根据探活命令的回显判定 OS。
+// 抽出来是为了单测可直接覆盖所有分支，无需真实 HTTP 调用。
+func classifyWebshellOSProbeOutput(out string) string {
+	if out == "" {
+		return ""
+	}
+	lower := strings.ToLower(out)
+
+	// Windows 强信号：cmd.exe 成功展开了 %OS% 变量
+	if strings.Contains(out, "Windows_NT") {
+		return "windows"
+	}
+	// 容错：部分老版本 Windows 可能 `%OS%` 展开为其他字样（极少见），再看 PATH/OS 等次级线索
+	if strings.Contains(lower, "microsoft windows") {
+		return "windows"
+	}
+
+	// Linux/Unix 强信号：`%OS%` 字面量被原样回显，说明 shell 不是 cmd.exe
+	if strings.Contains(out, "%OS%") {
+		return "linux"
+	}
+
+	// 次级线索：部分 webshell 在 Linux 上可能走了其他外壳（如 zsh/ash），
+	// 但它们对 `%OS%` 同样不展开；若命中 OSPROBE 头部却没拿到 %OS% 字面量，
+	// 说明回显被中途截断或过滤，保守返回空让上层 fallback。
+	return ""
+}
+
+// newHTTPExecFn 为 HTTP FileOp 路径构造"发命令取回显"的闭包，供探活复用。
+// 参数来自 HTTP 请求，复用 buildExecURL / buildExecBody 两个已有的命令编排器，
+// 确保探活包与实际文件操作包走完全一致的 webshell 协议（GET/POST、参数名、编码）。
+func (h *WebShellHandler) newHTTPExecFn(targetURL, password, shellType, method, cmdParam, encoding string) func(string) (string, bool) {
+	useGET := strings.ToUpper(strings.TrimSpace(method)) == "GET"
+	if strings.TrimSpace(cmdParam) == "" {
+		cmdParam = "cmd"
+	}
+	return func(cmd string) (string, bool) {
+		var (
+			httpReq *http.Request
+			err     error
+		)
+		if useGET {
+			u := h.buildExecURL(targetURL, shellType, password, cmdParam, cmd)
+			httpReq, err = http.NewRequest(http.MethodGet, u, nil)
+		} else {
+			body := h.buildExecBody(shellType, password, cmdParam, cmd)
+			httpReq, err = http.NewRequest(http.MethodPost, targetURL, bytes.NewReader(body))
+			if err == nil {
+				httpReq.Header.Set("Content-Type", "application/x-www-form-urlencoded")
+			}
+		}
+		if err != nil {
+			return "", false
+		}
+		httpReq.Header.Set("User-Agent", "Mozilla/5.0 (compatible; CyberStrikeAI-WebShell/1.0)")
+		resp, err := h.client.Do(httpReq)
+		if err != nil {
+			return "", false
+		}
+		defer resp.Body.Close()
+		raw, _ := io.ReadAll(resp.Body)
+		return decodeWebshellOutput(raw, encoding), resp.StatusCode == http.StatusOK
+	}
+}
+
+// persistDetectedOS 把探活结果回写到连接表；失败只记日志不阻断主流程。
+// 设计上故意只触发 UPDATE，不会新建记录，因此即便 connectionID 不存在也只是悄悄放弃。
+func (h *WebShellHandler) persistDetectedOS(connectionID, detected string) {
+	connectionID = strings.TrimSpace(connectionID)
+	detected = normalizeWebshellOS(detected)
+	if connectionID == "" || detected == "" || detected == "auto" {
+		return
+	}
+	conn, err := h.db.GetWebshellConnection(connectionID)
+	if err != nil || conn == nil {
+		// 不是所有调用方都能提供有效 ID（比如临时测试），这里静默返回
+		return
+	}
+	if normalizeWebshellOS(conn.OS) != "auto" {
+		// 用户已经显式选过 OS，尊重用户选择，不自动覆盖
+		return
+	}
+	conn.OS = detected
+	if err := h.db.UpdateWebshellConnection(conn); err != nil {
+		h.logger.Warn("webshell 探活结果持久化失败", zap.String("id", connectionID), zap.String("os", detected), zap.Error(err))
+		return
+	}
+	h.logger.Info("webshell auto OS 探活成功并持久化", zap.String("id", connectionID), zap.String("os", detected))
+}

internal/handler/webshell_probe_test.go

@@ -0,0 +1,68 @@
+package handler
+
+import "testing"
+
+func TestClassifyWebshellOSProbeOutput(t *testing.T) {
+	cases := []struct {
+		name string
+		in   string
+		want string
+	}{
+		{"Windows cmd 回显完整", ":OSPROBE_Windows_NT:END\r\n", "windows"},
+		{"Windows cmd 回显带额外空行", "\r\n:OSPROBE_Windows_NT:END\r\n", "windows"},
+		{"Windows 次级线索 - ver banner", "Microsoft Windows [版本 10.0.19045]\r\n", "windows"},
+		{"Linux sh 字面量回显", ":OSPROBE_%OS%:END\n", "linux"},
+		{"Linux 紧凑输出（无换行）", ":OSPROBE_%OS%:END", "linux"},
+		{"空输出 - 无法判定", "", ""},
+		{"被过滤的输出 - 无法判定", "something weird", ""},
+		{"仅有 OSPROBE 前缀但被截断 - 保守返回空", ":OSPROBE_:END", ""},
+	}
+	for _, c := range cases {
+		if got := classifyWebshellOSProbeOutput(c.in); got != c.want {
+			t.Errorf("case %q: got %q, want %q", c.name, got, c.want)
+		}
+	}
+}
+
+func TestProbeWebshellOSViaExec_SendsOneCommandOnly(t *testing.T) {
+	var calls []string
+	fn := func(cmd string) (string, bool) {
+		calls = append(calls, cmd)
+		return ":OSPROBE_Windows_NT:END", true
+	}
+	got := probeWebshellOSViaExec(fn)
+	if got != "windows" {
+		t.Fatalf("want windows, got %q", got)
+	}
+	if len(calls) != 1 {
+		t.Fatalf("probe should issue exactly one exec call, got %d: %v", len(calls), calls)
+	}
+	if calls[0] != webshellOSProbeCommand {
+		t.Errorf("probe command mismatch: got %q", calls[0])
+	}
+}
+
+func TestProbeWebshellOSViaExec_NotOkReturnsEmpty(t *testing.T) {
+	// HTTP 非 200 的场景：execFn 返回 ok=false，探活应放弃
+	fn := func(cmd string) (string, bool) { return "whatever", false }
+	if got := probeWebshellOSViaExec(fn); got != "" {
+		t.Errorf("want empty when exec not ok, got %q", got)
+	}
+}
+
+func TestProbeWebshellOSViaExec_NilSafeguard(t *testing.T) {
+	if got := probeWebshellOSViaExec(nil); got != "" {
+		t.Errorf("nil execFn should return empty, got %q", got)
+	}
+}
+
+func TestProbeWebshellOSViaExec_LinuxUname(t *testing.T) {
+	// 某些 webshell 对 `%OS%` 字面量也会过滤（例如安全规则），
+	// 但主要路径是"%OS% 字面量被原样回显"。这里覆盖标准 Linux 场景。
+	fn := func(cmd string) (string, bool) {
+		return ":OSPROBE_%OS%:END\n", true
+	}
+	if got := probeWebshellOSViaExec(fn); got != "linux" {
+		t.Errorf("Linux case: want linux, got %q", got)
+	}
+}