1package sftpd
2
3import (
4	"crypto/md5"
5	"crypto/sha1"
6	"crypto/sha256"
7	"crypto/sha512"
8	"errors"
9	"fmt"
10	"hash"
11	"io"
12	"os"
13	"os/exec"
14	"path"
15	"runtime/debug"
16	"strings"
17	"sync"
18
19	"github.com/google/shlex"
20	fscopy "github.com/otiai10/copy"
21	"golang.org/x/crypto/ssh"
22
23	"github.com/drakkan/sftpgo/v2/common"
24	"github.com/drakkan/sftpgo/v2/dataprovider"
25	"github.com/drakkan/sftpgo/v2/logger"
26	"github.com/drakkan/sftpgo/v2/metric"
27	"github.com/drakkan/sftpgo/v2/sdk"
28	"github.com/drakkan/sftpgo/v2/util"
29	"github.com/drakkan/sftpgo/v2/vfs"
30)
31
32const (
33	scpCmdName          = "scp"
34	sshCommandLogSender = "SSHCommand"
35)
36
37var (
38	errUnsupportedConfig = errors.New("command unsupported for this configuration")
39)
40
41type sshCommand struct {
42	command    string
43	args       []string
44	connection *Connection
45}
46
47type systemCommand struct {
48	cmd            *exec.Cmd
49	fsPath         string
50	quotaCheckPath string
51	fs             vfs.Fs
52}
53
54func processSSHCommand(payload []byte, connection *Connection, enabledSSHCommands []string) bool {
55	var msg sshSubsystemExecMsg
56	if err := ssh.Unmarshal(payload, &msg); err == nil {
57		name, args, err := parseCommandPayload(msg.Command)
58		connection.Log(logger.LevelDebug, "new ssh command: %#v args: %v num args: %v user: %v, error: %v",
59			name, args, len(args), connection.User.Username, err)
60		if err == nil && util.IsStringInSlice(name, enabledSSHCommands) {
61			connection.command = msg.Command
62			if name == scpCmdName && len(args) >= 2 {
63				connection.SetProtocol(common.ProtocolSCP)
64				scpCommand := scpCommand{
65					sshCommand: sshCommand{
66						command:    name,
67						connection: connection,
68						args:       args},
69				}
70				go scpCommand.handle() //nolint:errcheck
71				return true
72			}
73			if name != scpCmdName {
74				connection.SetProtocol(common.ProtocolSSH)
75				sshCommand := sshCommand{
76					command:    name,
77					connection: connection,
78					args:       args,
79				}
80				go sshCommand.handle() //nolint:errcheck
81				return true
82			}
83		} else {
84			connection.Log(logger.LevelInfo, "ssh command not enabled/supported: %#v", name)
85		}
86	}
87	err := connection.CloseFS()
88	connection.Log(logger.LevelDebug, "unable to unmarshal ssh command, close fs, err: %v", err)
89	return false
90}
91
92func (c *sshCommand) handle() (err error) {
93	defer func() {
94		if r := recover(); r != nil {
95			logger.Error(logSender, "", "panic in handle ssh command: %#v stack strace: %v", r, string(debug.Stack()))
96			err = common.ErrGenericFailure
97		}
98	}()
99	common.Connections.Add(c.connection)
100	defer common.Connections.Remove(c.connection.GetID())
101
102	c.connection.UpdateLastActivity()
103	if util.IsStringInSlice(c.command, sshHashCommands) {
104		return c.handleHashCommands()
105	} else if util.IsStringInSlice(c.command, systemCommands) {
106		command, err := c.getSystemCommand()
107		if err != nil {
108			return c.sendErrorResponse(err)
109		}
110		return c.executeSystemCommand(command)
111	} else if c.command == "cd" {
112		c.sendExitStatus(nil)
113	} else if c.command == "pwd" {
114		// hard coded response to "/"
115		c.connection.channel.Write([]byte("/\n")) //nolint:errcheck
116		c.sendExitStatus(nil)
117	} else if c.command == "sftpgo-copy" {
118		return c.handleSFTPGoCopy()
119	} else if c.command == "sftpgo-remove" {
120		return c.handleSFTPGoRemove()
121	}
122	return
123}
124
125func (c *sshCommand) handleSFTPGoCopy() error {
126	fsSrc, fsDst, sshSourcePath, sshDestPath, fsSourcePath, fsDestPath, err := c.getFsAndCopyPaths()
127	if err != nil {
128		return c.sendErrorResponse(err)
129	}
130	if !c.isLocalCopy(sshSourcePath, sshDestPath) {
131		return c.sendErrorResponse(errUnsupportedConfig)
132	}
133
134	if err := c.checkCopyDestination(fsDst, fsDestPath); err != nil {
135		return c.sendErrorResponse(c.connection.GetFsError(fsDst, err))
136	}
137
138	c.connection.Log(logger.LevelDebug, "requested copy %#v -> %#v sftp paths %#v -> %#v",
139		fsSourcePath, fsDestPath, sshSourcePath, sshDestPath)
140
141	fi, err := fsSrc.Lstat(fsSourcePath)
142	if err != nil {
143		return c.sendErrorResponse(c.connection.GetFsError(fsSrc, err))
144	}
145	if err := c.checkCopyPermissions(fsSrc, fsDst, fsSourcePath, fsDestPath, sshSourcePath, sshDestPath, fi); err != nil {
146		return c.sendErrorResponse(err)
147	}
148	filesNum := 0
149	filesSize := int64(0)
150	if fi.IsDir() {
151		filesNum, filesSize, err = fsSrc.GetDirSize(fsSourcePath)
152		if err != nil {
153			return c.sendErrorResponse(c.connection.GetFsError(fsSrc, err))
154		}
155		if c.connection.User.HasVirtualFoldersInside(sshSourcePath) {
156			err := errors.New("unsupported copy source: the source directory contains virtual folders")
157			return c.sendErrorResponse(err)
158		}
159		if c.connection.User.HasVirtualFoldersInside(sshDestPath) {
160			err := errors.New("unsupported copy source: the destination directory contains virtual folders")
161			return c.sendErrorResponse(err)
162		}
163	} else if fi.Mode().IsRegular() {
164		if !c.connection.User.IsFileAllowed(sshDestPath) {
165			err := errors.New("unsupported copy destination: this file is not allowed")
166			return c.sendErrorResponse(err)
167		}
168		filesNum = 1
169		filesSize = fi.Size()
170	} else {
171		err := errors.New("unsupported copy source: only files and directories are supported")
172		return c.sendErrorResponse(err)
173	}
174	if err := c.checkCopyQuota(filesNum, filesSize, sshDestPath); err != nil {
175		return c.sendErrorResponse(err)
176	}
177	c.connection.Log(logger.LevelDebug, "start copy %#v -> %#v", fsSourcePath, fsDestPath)
178	err = fscopy.Copy(fsSourcePath, fsDestPath, fscopy.Options{
179		OnSymlink: func(src string) fscopy.SymlinkAction {
180			return fscopy.Skip
181		},
182	})
183	if err != nil {
184		return c.sendErrorResponse(c.connection.GetFsError(fsSrc, err))
185	}
186	c.updateQuota(sshDestPath, filesNum, filesSize)
187	c.connection.channel.Write([]byte("OK\n")) //nolint:errcheck
188	c.sendExitStatus(nil)
189	return nil
190}
191
192func (c *sshCommand) handleSFTPGoRemove() error {
193	sshDestPath, err := c.getRemovePath()
194	if err != nil {
195		return c.sendErrorResponse(err)
196	}
197	if !c.connection.User.HasPerm(dataprovider.PermDelete, path.Dir(sshDestPath)) {
198		return c.sendErrorResponse(common.ErrPermissionDenied)
199	}
200	fs, fsDestPath, err := c.connection.GetFsAndResolvedPath(sshDestPath)
201	if err != nil {
202		return c.sendErrorResponse(err)
203	}
204	if !vfs.IsLocalOrCryptoFs(fs) {
205		return c.sendErrorResponse(errUnsupportedConfig)
206	}
207	fi, err := fs.Lstat(fsDestPath)
208	if err != nil {
209		return c.sendErrorResponse(c.connection.GetFsError(fs, err))
210	}
211	filesNum := 0
212	filesSize := int64(0)
213	if fi.IsDir() {
214		filesNum, filesSize, err = fs.GetDirSize(fsDestPath)
215		if err != nil {
216			return c.sendErrorResponse(c.connection.GetFsError(fs, err))
217		}
218		if sshDestPath == "/" {
219			err := errors.New("removing root dir is not allowed")
220			return c.sendErrorResponse(err)
221		}
222		if c.connection.User.HasVirtualFoldersInside(sshDestPath) {
223			err := errors.New("unsupported remove source: this directory contains virtual folders")
224			return c.sendErrorResponse(err)
225		}
226		if c.connection.User.IsVirtualFolder(sshDestPath) {
227			err := errors.New("unsupported remove source: this directory is a virtual folder")
228			return c.sendErrorResponse(err)
229		}
230	} else if fi.Mode().IsRegular() {
231		filesNum = 1
232		filesSize = fi.Size()
233	} else {
234		err := errors.New("unsupported remove source: only files and directories are supported")
235		return c.sendErrorResponse(err)
236	}
237
238	err = os.RemoveAll(fsDestPath)
239	if err != nil {
240		return c.sendErrorResponse(err)
241	}
242	c.updateQuota(sshDestPath, -filesNum, -filesSize)
243	c.connection.channel.Write([]byte("OK\n")) //nolint:errcheck
244	c.sendExitStatus(nil)
245	return nil
246}
247
248func (c *sshCommand) updateQuota(sshDestPath string, filesNum int, filesSize int64) {
249	vfolder, err := c.connection.User.GetVirtualFolderForPath(sshDestPath)
250	if err == nil {
251		dataprovider.UpdateVirtualFolderQuota(&vfolder.BaseVirtualFolder, filesNum, filesSize, false) //nolint:errcheck
252		if vfolder.IsIncludedInUserQuota() {
253			dataprovider.UpdateUserQuota(&c.connection.User, filesNum, filesSize, false) //nolint:errcheck
254		}
255	} else {
256		dataprovider.UpdateUserQuota(&c.connection.User, filesNum, filesSize, false) //nolint:errcheck
257	}
258}
259
260func (c *sshCommand) handleHashCommands() error {
261	var h hash.Hash
262	if c.command == "md5sum" {
263		h = md5.New()
264	} else if c.command == "sha1sum" {
265		h = sha1.New()
266	} else if c.command == "sha256sum" {
267		h = sha256.New()
268	} else if c.command == "sha384sum" {
269		h = sha512.New384()
270	} else {
271		h = sha512.New()
272	}
273	var response string
274	if len(c.args) == 0 {
275		// without args we need to read the string to hash from stdin
276		buf := make([]byte, 4096)
277		n, err := c.connection.channel.Read(buf)
278		if err != nil && err != io.EOF {
279			return c.sendErrorResponse(err)
280		}
281		h.Write(buf[:n]) //nolint:errcheck
282		response = fmt.Sprintf("%x  -\n", h.Sum(nil))
283	} else {
284		sshPath := c.getDestPath()
285		if !c.connection.User.IsFileAllowed(sshPath) {
286			c.connection.Log(logger.LevelInfo, "hash not allowed for file %#v", sshPath)
287			return c.sendErrorResponse(c.connection.GetPermissionDeniedError())
288		}
289		fs, fsPath, err := c.connection.GetFsAndResolvedPath(sshPath)
290		if err != nil {
291			return c.sendErrorResponse(err)
292		}
293		if !c.connection.User.HasPerm(dataprovider.PermListItems, sshPath) {
294			return c.sendErrorResponse(c.connection.GetPermissionDeniedError())
295		}
296		hash, err := c.computeHashForFile(fs, h, fsPath)
297		if err != nil {
298			return c.sendErrorResponse(c.connection.GetFsError(fs, err))
299		}
300		response = fmt.Sprintf("%v  %v\n", hash, sshPath)
301	}
302	c.connection.channel.Write([]byte(response)) //nolint:errcheck
303	c.sendExitStatus(nil)
304	return nil
305}
306
307func (c *sshCommand) executeSystemCommand(command systemCommand) error {
308	sshDestPath := c.getDestPath()
309	if !c.isLocalPath(sshDestPath) {
310		return c.sendErrorResponse(errUnsupportedConfig)
311	}
312	quotaResult := c.connection.HasSpace(true, false, command.quotaCheckPath)
313	if !quotaResult.HasSpace {
314		return c.sendErrorResponse(common.ErrQuotaExceeded)
315	}
316	perms := []string{dataprovider.PermDownload, dataprovider.PermUpload, dataprovider.PermCreateDirs, dataprovider.PermListItems,
317		dataprovider.PermOverwrite, dataprovider.PermDelete}
318	if !c.connection.User.HasPerms(perms, sshDestPath) {
319		return c.sendErrorResponse(c.connection.GetPermissionDeniedError())
320	}
321
322	initialFiles, initialSize, err := c.getSizeForPath(command.fs, command.fsPath)
323	if err != nil {
324		return c.sendErrorResponse(err)
325	}
326
327	stdin, err := command.cmd.StdinPipe()
328	if err != nil {
329		return c.sendErrorResponse(err)
330	}
331	stdout, err := command.cmd.StdoutPipe()
332	if err != nil {
333		return c.sendErrorResponse(err)
334	}
335	stderr, err := command.cmd.StderrPipe()
336	if err != nil {
337		return c.sendErrorResponse(err)
338	}
339	err = command.cmd.Start()
340	if err != nil {
341		return c.sendErrorResponse(err)
342	}
343
344	closeCmdOnError := func() {
345		c.connection.Log(logger.LevelDebug, "kill cmd: %#v and close ssh channel after read or write error",
346			c.connection.command)
347		killerr := command.cmd.Process.Kill()
348		closerr := c.connection.channel.Close()
349		c.connection.Log(logger.LevelDebug, "kill cmd error: %v close channel error: %v", killerr, closerr)
350	}
351	var once sync.Once
352	commandResponse := make(chan bool)
353
354	remainingQuotaSize := quotaResult.GetRemainingSize()
355
356	go func() {
357		defer stdin.Close()
358		baseTransfer := common.NewBaseTransfer(nil, c.connection.BaseConnection, nil, command.fsPath, command.fsPath, sshDestPath,
359			common.TransferUpload, 0, 0, remainingQuotaSize, false, command.fs)
360		transfer := newTransfer(baseTransfer, nil, nil, nil)
361
362		w, e := transfer.copyFromReaderToWriter(stdin, c.connection.channel)
363		c.connection.Log(logger.LevelDebug, "command: %#v, copy from remote command to sdtin ended, written: %v, "+
364			"initial remaining quota: %v, err: %v", c.connection.command, w, remainingQuotaSize, e)
365		if e != nil {
366			once.Do(closeCmdOnError)
367		}
368	}()
369
370	go func() {
371		baseTransfer := common.NewBaseTransfer(nil, c.connection.BaseConnection, nil, command.fsPath, command.fsPath, sshDestPath,
372			common.TransferDownload, 0, 0, 0, false, command.fs)
373		transfer := newTransfer(baseTransfer, nil, nil, nil)
374
375		w, e := transfer.copyFromReaderToWriter(c.connection.channel, stdout)
376		c.connection.Log(logger.LevelDebug, "command: %#v, copy from sdtout to remote command ended, written: %v err: %v",
377			c.connection.command, w, e)
378		if e != nil {
379			once.Do(closeCmdOnError)
380		}
381		commandResponse <- true
382	}()
383
384	go func() {
385		baseTransfer := common.NewBaseTransfer(nil, c.connection.BaseConnection, nil, command.fsPath, command.fsPath, sshDestPath,
386			common.TransferDownload, 0, 0, 0, false, command.fs)
387		transfer := newTransfer(baseTransfer, nil, nil, nil)
388
389		w, e := transfer.copyFromReaderToWriter(c.connection.channel.(ssh.Channel).Stderr(), stderr)
390		c.connection.Log(logger.LevelDebug, "command: %#v, copy from sdterr to remote command ended, written: %v err: %v",
391			c.connection.command, w, e)
392		// os.ErrClosed means that the command is finished so we don't need to do anything
393		if (e != nil && !errors.Is(e, os.ErrClosed)) || w > 0 {
394			once.Do(closeCmdOnError)
395		}
396	}()
397
398	<-commandResponse
399	err = command.cmd.Wait()
400	c.sendExitStatus(err)
401
402	numFiles, dirSize, errSize := c.getSizeForPath(command.fs, command.fsPath)
403	if errSize == nil {
404		c.updateQuota(sshDestPath, numFiles-initialFiles, dirSize-initialSize)
405	}
406	c.connection.Log(logger.LevelDebug, "command %#v finished for path %#v, initial files %v initial size %v "+
407		"current files %v current size %v size err: %v", c.connection.command, command.fsPath, initialFiles, initialSize,
408		numFiles, dirSize, errSize)
409	return c.connection.GetFsError(command.fs, err)
410}
411
412func (c *sshCommand) isSystemCommandAllowed() error {
413	sshDestPath := c.getDestPath()
414	if c.connection.User.IsVirtualFolder(sshDestPath) {
415		// overlapped virtual path are not allowed
416		return nil
417	}
418	if c.connection.User.HasVirtualFoldersInside(sshDestPath) {
419		c.connection.Log(logger.LevelDebug, "command %#v is not allowed, path %#v has virtual folders inside it, user %#v",
420			c.command, sshDestPath, c.connection.User.Username)
421		return errUnsupportedConfig
422	}
423	for _, f := range c.connection.User.Filters.FilePatterns {
424		if f.Path == sshDestPath {
425			c.connection.Log(logger.LevelDebug,
426				"command %#v is not allowed inside folders with file patterns filters %#v user %#v",
427				c.command, sshDestPath, c.connection.User.Username)
428			return errUnsupportedConfig
429		}
430		if len(sshDestPath) > len(f.Path) {
431			if strings.HasPrefix(sshDestPath, f.Path+"/") || f.Path == "/" {
432				c.connection.Log(logger.LevelDebug,
433					"command %#v is not allowed it includes folders with file patterns filters %#v user %#v",
434					c.command, sshDestPath, c.connection.User.Username)
435				return errUnsupportedConfig
436			}
437		}
438		if len(sshDestPath) < len(f.Path) {
439			if strings.HasPrefix(sshDestPath+"/", f.Path) || sshDestPath == "/" {
440				c.connection.Log(logger.LevelDebug,
441					"command %#v is not allowed inside folder with file patterns filters %#v user %#v",
442					c.command, sshDestPath, c.connection.User.Username)
443				return errUnsupportedConfig
444			}
445		}
446	}
447	return nil
448}
449
450func (c *sshCommand) getSystemCommand() (systemCommand, error) {
451	command := systemCommand{
452		cmd:            nil,
453		fs:             nil,
454		fsPath:         "",
455		quotaCheckPath: "",
456	}
457	args := make([]string, len(c.args))
458	copy(args, c.args)
459	var fsPath, quotaPath string
460	sshPath := c.getDestPath()
461	fs, err := c.connection.User.GetFilesystemForPath(sshPath, c.connection.ID)
462	if err != nil {
463		return command, err
464	}
465	if len(c.args) > 0 {
466		var err error
467		fsPath, err = fs.ResolvePath(sshPath)
468		if err != nil {
469			return command, c.connection.GetFsError(fs, err)
470		}
471		quotaPath = sshPath
472		fi, err := fs.Stat(fsPath)
473		if err == nil && fi.IsDir() {
474			// if the target is an existing dir the command will write inside this dir
475			// so we need to check the quota for this directory and not its parent dir
476			quotaPath = path.Join(sshPath, "fakecontent")
477		}
478		if strings.HasSuffix(sshPath, "/") && !strings.HasSuffix(fsPath, string(os.PathSeparator)) {
479			fsPath += string(os.PathSeparator)
480			c.connection.Log(logger.LevelDebug, "path separator added to fsPath %#v", fsPath)
481		}
482		args = args[:len(args)-1]
483		args = append(args, fsPath)
484	}
485	if err := c.isSystemCommandAllowed(); err != nil {
486		return command, errUnsupportedConfig
487	}
488	if c.command == "rsync" {
489		// we cannot avoid that rsync creates symlinks so if the user has the permission
490		// to create symlinks we add the option --safe-links to the received rsync command if
491		// it is not already set. This should prevent to create symlinks that point outside
492		// the home dir.
493		// If the user cannot create symlinks we add the option --munge-links, if it is not
494		// already set. This should make symlinks unusable (but manually recoverable)
495		if c.connection.User.HasPerm(dataprovider.PermCreateSymlinks, c.getDestPath()) {
496			if !util.IsStringInSlice("--safe-links", args) {
497				args = append([]string{"--safe-links"}, args...)
498			}
499		} else {
500			if !util.IsStringInSlice("--munge-links", args) {
501				args = append([]string{"--munge-links"}, args...)
502			}
503		}
504	}
505	c.connection.Log(logger.LevelDebug, "new system command %#v, with args: %+v fs path %#v quota check path %#v",
506		c.command, args, fsPath, quotaPath)
507	cmd := exec.Command(c.command, args...)
508	uid := c.connection.User.GetUID()
509	gid := c.connection.User.GetGID()
510	cmd = wrapCmd(cmd, uid, gid)
511	command.cmd = cmd
512	command.fsPath = fsPath
513	command.quotaCheckPath = quotaPath
514	command.fs = fs
515	return command, nil
516}
517
518// for the supported commands, the destination path, if any, is the last argument
519func (c *sshCommand) getDestPath() string {
520	if len(c.args) == 0 {
521		return ""
522	}
523	return cleanCommandPath(c.args[len(c.args)-1])
524}
525
526// for the supported commands, the destination path, if any, is the second-last argument
527func (c *sshCommand) getSourcePath() string {
528	if len(c.args) < 2 {
529		return ""
530	}
531	return cleanCommandPath(c.args[len(c.args)-2])
532}
533
534func cleanCommandPath(name string) string {
535	name = strings.Trim(name, "'")
536	name = strings.Trim(name, "\"")
537	result := util.CleanPath(name)
538	if strings.HasSuffix(name, "/") && !strings.HasSuffix(result, "/") {
539		result += "/"
540	}
541	return result
542}
543
544func (c *sshCommand) getFsAndCopyPaths() (vfs.Fs, vfs.Fs, string, string, string, string, error) {
545	sshSourcePath := strings.TrimSuffix(c.getSourcePath(), "/")
546	sshDestPath := c.getDestPath()
547	if strings.HasSuffix(sshDestPath, "/") {
548		sshDestPath = path.Join(sshDestPath, path.Base(sshSourcePath))
549	}
550	if sshSourcePath == "" || sshDestPath == "" || len(c.args) != 2 {
551		err := errors.New("usage sftpgo-copy <source dir path> <destination dir path>")
552		return nil, nil, "", "", "", "", err
553	}
554	fsSrc, fsSourcePath, err := c.connection.GetFsAndResolvedPath(sshSourcePath)
555	if err != nil {
556		return nil, nil, "", "", "", "", err
557	}
558	fsDst, fsDestPath, err := c.connection.GetFsAndResolvedPath(sshDestPath)
559	if err != nil {
560		return nil, nil, "", "", "", "", err
561	}
562	return fsSrc, fsDst, sshSourcePath, sshDestPath, fsSourcePath, fsDestPath, nil
563}
564
565func (c *sshCommand) hasCopyPermissions(sshSourcePath, sshDestPath string, srcInfo os.FileInfo) bool {
566	if !c.connection.User.HasPerm(dataprovider.PermListItems, path.Dir(sshSourcePath)) {
567		return false
568	}
569	if srcInfo.IsDir() {
570		return c.connection.User.HasPerm(dataprovider.PermCreateDirs, path.Dir(sshDestPath))
571	} else if srcInfo.Mode()&os.ModeSymlink != 0 {
572		return c.connection.User.HasPerm(dataprovider.PermCreateSymlinks, path.Dir(sshDestPath))
573	}
574	return c.connection.User.HasPerm(dataprovider.PermUpload, path.Dir(sshDestPath))
575}
576
577// fsSourcePath must be a directory
578func (c *sshCommand) checkRecursiveCopyPermissions(fsSrc vfs.Fs, fsDst vfs.Fs, fsSourcePath, fsDestPath, sshDestPath string) error {
579	if !c.connection.User.HasPerm(dataprovider.PermCreateDirs, path.Dir(sshDestPath)) {
580		return common.ErrPermissionDenied
581	}
582	dstPerms := []string{
583		dataprovider.PermCreateDirs,
584		dataprovider.PermCreateSymlinks,
585		dataprovider.PermUpload,
586	}
587
588	err := fsSrc.Walk(fsSourcePath, func(walkedPath string, info os.FileInfo, err error) error {
589		if err != nil {
590			return c.connection.GetFsError(fsSrc, err)
591		}
592		fsDstSubPath := strings.Replace(walkedPath, fsSourcePath, fsDestPath, 1)
593		sshSrcSubPath := fsSrc.GetRelativePath(walkedPath)
594		sshDstSubPath := fsDst.GetRelativePath(fsDstSubPath)
595		// If the current dir has no subdirs with defined permissions inside it
596		// and it has all the possible permissions we can stop scanning
597		if !c.connection.User.HasPermissionsInside(path.Dir(sshSrcSubPath)) &&
598			!c.connection.User.HasPermissionsInside(path.Dir(sshDstSubPath)) {
599			if c.connection.User.HasPerm(dataprovider.PermListItems, path.Dir(sshSrcSubPath)) &&
600				c.connection.User.HasPerms(dstPerms, path.Dir(sshDstSubPath)) {
601				return common.ErrSkipPermissionsCheck
602			}
603		}
604		if !c.hasCopyPermissions(sshSrcSubPath, sshDstSubPath, info) {
605			return common.ErrPermissionDenied
606		}
607		return nil
608	})
609	if err == common.ErrSkipPermissionsCheck {
610		err = nil
611	}
612	return err
613}
614
615func (c *sshCommand) checkCopyPermissions(fsSrc vfs.Fs, fsDst vfs.Fs, fsSourcePath, fsDestPath, sshSourcePath, sshDestPath string, info os.FileInfo) error {
616	if info.IsDir() {
617		return c.checkRecursiveCopyPermissions(fsSrc, fsDst, fsSourcePath, fsDestPath, sshDestPath)
618	}
619	if !c.hasCopyPermissions(sshSourcePath, sshDestPath, info) {
620		return c.connection.GetPermissionDeniedError()
621	}
622	return nil
623}
624
625func (c *sshCommand) getRemovePath() (string, error) {
626	sshDestPath := c.getDestPath()
627	if sshDestPath == "" || len(c.args) != 1 {
628		err := errors.New("usage sftpgo-remove <destination path>")
629		return "", err
630	}
631	if len(sshDestPath) > 1 {
632		sshDestPath = strings.TrimSuffix(sshDestPath, "/")
633	}
634	return sshDestPath, nil
635}
636
637func (c *sshCommand) isLocalPath(virtualPath string) bool {
638	folder, err := c.connection.User.GetVirtualFolderForPath(virtualPath)
639	if err != nil {
640		return c.connection.User.FsConfig.Provider == sdk.LocalFilesystemProvider
641	}
642	return folder.FsConfig.Provider == sdk.LocalFilesystemProvider
643}
644
645func (c *sshCommand) isLocalCopy(virtualSourcePath, virtualTargetPath string) bool {
646	if !c.isLocalPath(virtualSourcePath) {
647		return false
648	}
649
650	return c.isLocalPath(virtualTargetPath)
651}
652
653func (c *sshCommand) checkCopyDestination(fs vfs.Fs, fsDestPath string) error {
654	_, err := fs.Lstat(fsDestPath)
655	if err == nil {
656		err := errors.New("invalid copy destination: cannot overwrite an existing file or directory")
657		return err
658	} else if !fs.IsNotExist(err) {
659		return err
660	}
661	return nil
662}
663
664func (c *sshCommand) checkCopyQuota(numFiles int, filesSize int64, requestPath string) error {
665	quotaResult := c.connection.HasSpace(true, false, requestPath)
666	if !quotaResult.HasSpace {
667		return common.ErrQuotaExceeded
668	}
669	if quotaResult.QuotaFiles > 0 {
670		remainingFiles := quotaResult.GetRemainingFiles()
671		if remainingFiles < numFiles {
672			c.connection.Log(logger.LevelDebug, "copy not allowed, file limit will be exceeded, "+
673				"remaining files: %v to copy: %v", remainingFiles, numFiles)
674			return common.ErrQuotaExceeded
675		}
676	}
677	if quotaResult.QuotaSize > 0 {
678		remainingSize := quotaResult.GetRemainingSize()
679		if remainingSize < filesSize {
680			c.connection.Log(logger.LevelDebug, "copy not allowed, size limit will be exceeded, "+
681				"remaining size: %v to copy: %v", remainingSize, filesSize)
682			return common.ErrQuotaExceeded
683		}
684	}
685	return nil
686}
687
688func (c *sshCommand) getSizeForPath(fs vfs.Fs, name string) (int, int64, error) {
689	if dataprovider.GetQuotaTracking() > 0 {
690		fi, err := fs.Lstat(name)
691		if err != nil {
692			if fs.IsNotExist(err) {
693				return 0, 0, nil
694			}
695			c.connection.Log(logger.LevelDebug, "unable to stat %#v error: %v", name, err)
696			return 0, 0, err
697		}
698		if fi.IsDir() {
699			files, size, err := fs.GetDirSize(name)
700			if err != nil {
701				c.connection.Log(logger.LevelDebug, "unable to get size for dir %#v error: %v", name, err)
702			}
703			return files, size, err
704		} else if fi.Mode().IsRegular() {
705			return 1, fi.Size(), nil
706		}
707	}
708	return 0, 0, nil
709}
710
711func (c *sshCommand) sendErrorResponse(err error) error {
712	errorString := fmt.Sprintf("%v: %v %v\n", c.command, c.getDestPath(), err)
713	c.connection.channel.Write([]byte(errorString)) //nolint:errcheck
714	c.sendExitStatus(err)
715	return err
716}
717
718func (c *sshCommand) sendExitStatus(err error) {
719	status := uint32(0)
720	vCmdPath := c.getDestPath()
721	cmdPath := ""
722	targetPath := ""
723	vTargetPath := ""
724	if c.command == "sftpgo-copy" {
725		vTargetPath = vCmdPath
726		vCmdPath = c.getSourcePath()
727	}
728	if err != nil {
729		status = uint32(1)
730		c.connection.Log(logger.LevelWarn, "command failed: %#v args: %v user: %v err: %v",
731			c.command, c.args, c.connection.User.Username, err)
732	}
733	exitStatus := sshSubsystemExitStatus{
734		Status: status,
735	}
736	_, errClose := c.connection.channel.(ssh.Channel).SendRequest("exit-status", false, ssh.Marshal(&exitStatus))
737	c.connection.Log(logger.LevelDebug, "exit status sent, error: %v", errClose)
738	c.connection.channel.Close()
739	// for scp we notify single uploads/downloads
740	if c.command != scpCmdName {
741		metric.SSHCommandCompleted(err)
742		if vCmdPath != "" {
743			_, p, errFs := c.connection.GetFsAndResolvedPath(vCmdPath)
744			if errFs == nil {
745				cmdPath = p
746			}
747		}
748		if vTargetPath != "" {
749			_, p, errFs := c.connection.GetFsAndResolvedPath(vTargetPath)
750			if errFs == nil {
751				targetPath = p
752			}
753		}
754		common.ExecuteActionNotification(&c.connection.User, common.OperationSSHCmd, cmdPath, vCmdPath, targetPath,
755			vTargetPath, c.command, common.ProtocolSSH, c.connection.GetRemoteIP(), 0, err)
756		if err == nil {
757			logger.CommandLog(sshCommandLogSender, cmdPath, targetPath, c.connection.User.Username, "", c.connection.ID,
758				common.ProtocolSSH, -1, -1, "", "", c.connection.command, -1, c.connection.GetLocalAddress(),
759				c.connection.GetRemoteAddress())
760		}
761	}
762}
763
764func (c *sshCommand) computeHashForFile(fs vfs.Fs, hasher hash.Hash, path string) (string, error) {
765	hash := ""
766	f, r, _, err := fs.Open(path, 0)
767	if err != nil {
768		return hash, err
769	}
770	var reader io.ReadCloser
771	if f != nil {
772		reader = f
773	} else {
774		reader = r
775	}
776	defer reader.Close()
777	_, err = io.Copy(hasher, reader)
778	if err == nil {
779		hash = fmt.Sprintf("%x", hasher.Sum(nil))
780	}
781	return hash, err
782}
783
784func parseCommandPayload(command string) (string, []string, error) {
785	parts, err := shlex.Split(command)
786	if err == nil && len(parts) == 0 {
787		err = fmt.Errorf("invalid command: %#v", command)
788	}
789	if err != nil {
790		return "", []string{}, err
791	}
792	if len(parts) < 2 {
793		return parts[0], []string{}, nil
794	}
795	return parts[0], parts[1:], nil
796}
797