Add symlink support to smbclient

impacket/examples/smbclient.py

@@ -25,6 +25,7 @@
 import cmd
 import os
 import ntpath
+import shlex
 
 from six import PY2
 from impacket.dcerpc.v5 import samr, transport, srvs
@@ -123,6 +124,8 @@ def do_help(self,line):
  mget {mask} - downloads all files from the current directory matching the provided mask
  cat {filename} - reads the filename from the current path
  mount {target,path} - creates a mount point from {path} to {target} (admin required)
+ create_symlink {target,path} - creates a symlink from {path} to {target}, can be file or dir, path must exist (admin required)
+ remove_symlink {path} - removes the symlink at {path} without deleting the directory (admin required)
  umount {path} - removes the mount point at {path} without deleting the directory (admin required)
  list_snapshots {path} - lists the vss snapshots for the specified path
  info - returns NetrServerInfo main results
@@ -671,6 +674,20 @@ def do_umount(self, mountpoint):
 
         self.smb.removeMountPoint(self.tid, mountPath)
 
+    def do_create_symlink(self, line):
+        target, path = shlex.split(line)
+        target = target.replace('/','\\')
+        path = path.replace('/','\\')
+        if not path.startswith('\\'):
+            path = ntpath.join(self.pwd, path)
+        self.smb.createSymlink(self.tid, path, target)
+
+    def do_remove_symlink(self, line):
+        path = line.replace('/','\\')
+        if not path.startswith('\\'):
+            path = ntpath.join(self.pwd, path)
+        self.smb.removeSymlink(self.tid, path)
+
     def do_EOF(self, line):
         print('Bye!\n')
         return True

impacket/smb3structs.py

@@ -1305,6 +1305,28 @@ class MOUNT_POINT_REPARSE_GUID_DATA_STRUCTURE(Structure):
         ("DataBuffer", ":")
     )
 
+class SYMLINK_REPARSE_DATA_STRUCTURE(Structure):
+    structure = (
+        ('ReparseTag', '<L=0xA000000C'),
+        ('ReparseDataLen', '<H=len(self["PathBuffer"]) + 8'),
+        ('Reserved', '<H=0'),
+        ('SubstituteNameOffset', '<H=0'),
+        ('SubstituteNameLength', '<H=0'),
+        ('PrintNameOffset', '<H=0'),
+        ('PrintNameLength', '<H=0'),
+        ('Flags', '<L=0'),
+        ('PathBuffer', ':')
+    )
+
+class SYMLINK_REPARSE_GUID_DATA_STRUCTURE(Structure):
+    structure = (
+        ('ReparseTag', '<L=0xA000000C'),
+        ('ReparseDataLen', '<H=len(self["DataBuffer"])'),
+        ('Reserved', '<H=0'),
+        ('ReparseGuid', '16s=""'),
+        ('DataBuffer', ':')
+    )
+
 class SMB2Ioctl_Response(Structure):
     structure = (
         ('StructureSize','<H=49'),

impacket/smbconnection.py

@@ -38,10 +38,11 @@
 ## Access Mask.
 from impacket.smb import FILE_READ_DATA , FILE_WRITE_DATA, GENERIC_READ, GENERIC_WRITE, GENERIC_ALL, READ_CONTROL, \
                          FILE_READ_ATTRIBUTES, FILE_READ_EA, SYNCHRONIZE
-
 ## Share Access Modes.
 from impacket.smb import FILE_SHARE_READ, FILE_SHARE_WRITE, FILE_SHARE_DELETE
 
+from impacket.smb3structs import SMB2_0_IOCTL_IS_FSCTL, FSCTL_DELETE_REPARSE_POINT, FSCTL_SET_REPARSE_POINT, SYMLINK_REPARSE_DATA_STRUCTURE, SYMLINK_REPARSE_GUID_DATA_STRUCTURE
+
 
 class SMBConnection:
     """
@@ -966,6 +967,52 @@ def removeMountPoint(self, tid, path):
 
         self.closeFile(tid, fid)
 
+    def createSymlink(self, tid, path, target):
+        """
+        creates a symlink from path to target
+
+        :param int tid: tree id of current connection
+        :param string path: file or directory where symlink is created (must already exist)
+        :param string target: file or directory where symlink will point to (can be inexistent)
+
+        :raise SessionError: if error
+        """
+
+        substitute_name = f'\\??\\{target}'.encode('utf-16le')
+        print_name = target.encode('utf-16le')
+        reparse_data = SYMLINK_REPARSE_DATA_STRUCTURE()
+        reparse_data['PathBuffer'] = print_name + substitute_name
+        reparse_data['ReparseDataLen'] = len(print_name + substitute_name) + 12
+        reparse_data['SubstituteNameOffset'] = len(print_name)
+        reparse_data['SubstituteNameLength'] = len(substitute_name)
+        reparse_data['PrintNameOffset'] = 0
+        reparse_data['PrintNameLength'] = len(print_name)
+
+        fid = self.openFile(tid, path, GENERIC_READ|GENERIC_WRITE, creationOption=FILE_OPEN_REPARSE_POINT)
+        try:
+            self._SMBConnection.ioctl(tid, fid, FSCTL_SET_REPARSE_POINT, flags=SMB2_0_IOCTL_IS_FSCTL, inputBlob=reparse_data)
+        finally:
+            self.closeFile(tid, fid)
+
+    def removeSymlink(self, tid, path):
+        """
+        removes a symlink without deleting the underlying file or directory
+
+        :param int tid: tree id of current connection
+        :param string path: path to symlink
+
+        :raise SessionError: if error
+        """
+
+        reparse_data = SYMLINK_REPARSE_GUID_DATA_STRUCTURE()
+        reparse_data['DataBuffer'] = b''
+
+        fid = self.openFile(tid, path, GENERIC_READ|GENERIC_WRITE, creationOption=FILE_OPEN_REPARSE_POINT)
+        try:
+            self._SMBConnection.ioctl(tid, fid, FSCTL_DELETE_REPARSE_POINT, flags=SMB2_0_IOCTL_IS_FSCTL, inputBlob=reparse_data)
+        finally:
+            self.closeFile(tid, fid)
+
     def rename(self, shareName, oldPath, newPath):
         """
         Renames a file/directory.