# -*- Mode:Python; indent-tabs-mode:nil; tab-width:4; encoding:utf-8 -*-
#
# Copyright 2002 Ben Escoto <ben@emerose.org>
# Copyright 2007 Kenneth Loafman <kenneth@loafman.com>
#
# This file is part of duplicity.
#
# Duplicity is free software; you can redistribute it and/or modify it
# under the terms of the GNU General Public License as published by the
# Free Software Foundation; either version 2 of the License, or (at your
# option) any later version.
#
# Duplicity is distributed in the hope that it will be useful, but
# WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
# General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with duplicity; if not, write to the Free Software Foundation,
# Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
# The following can be redefined to use different shell commands from
# ssh or scp or to add more arguments. However, the replacements must
# have the same syntax. Also these strings will be executed by the
# shell, so shouldn't have strange characters in them.
from __future__ import division
from future import standard_library
standard_library.install_aliases()
from builtins import map
import os
import re
from duplicity import config
from duplicity import log
from duplicity import util
from duplicity.errors import BackendException
import duplicity.backend
[docs]class SSHPExpectBackend(duplicity.backend.Backend):
u"""This backend copies files using scp. List not supported. Filenames
should not need any quoting or this will break."""
[docs] def __init__(self, parsed_url):
u"""scpBackend initializer"""
duplicity.backend.Backend.__init__(self, parsed_url)
try:
global pexpect
import pexpect
except ImportError:
raise
if pexpect.__version__ < u"4.5.0":
log.FatalError(u"""
The version of pexpect, '%s`, is too old. We need version 4.5.0 or above to run.
See https://gitlab.com/duplicity/duplicity/-/issues/125 for the gory details.
Use "python3 -m pip install pexpect" to install the latest version.
""" % pexexpect.__version__)
self.retry_delay = 10
self.scp_command = u"scp"
if config.scp_command:
self.scp_command = config.scp_command
self.sftp_command = u"sftp"
if config.sftp_command:
self.sftp_command = config.sftp_command
self.scheme = duplicity.backend.strip_prefix(parsed_url.scheme, u'pexpect')
self.use_scp = (self.scheme == u'scp')
# host string of form [user@]hostname
if parsed_url.username:
self.host_string = parsed_url.username + u"@" + parsed_url.hostname
else:
self.host_string = parsed_url.hostname
# make sure remote_dir is always valid
if parsed_url.path:
# remove leading '/'
self.remote_dir = re.sub(r'^/', r'', parsed_url.path, 1)
else:
self.remote_dir = u'.'
self.remote_prefix = self.remote_dir + u'/'
# maybe use different ssh port
if parsed_url.port:
config.ssh_options = config.ssh_options + u" -oPort=%s" % parsed_url.port
# set some defaults if user has not specified already.
if u"ServerAliveInterval" not in config.ssh_options:
config.ssh_options += u" -oServerAliveInterval=%d" % ((int)(config.timeout / 2))
if u"ServerAliveCountMax" not in config.ssh_options:
config.ssh_options += u" -oServerAliveCountMax=2"
# set up password
self.use_getpass = config.ssh_askpass
self.password = self.get_password()
[docs] def run_scp_command(self, commandline):
u""" Run an scp command, responding to password prompts """
log.Info(u"Running '%s'" % commandline)
child = pexpect.spawn(commandline, timeout=None, use_poll=True)
if config.ssh_askpass:
state = u"authorizing"
else:
state = u"copying"
while 1:
if state == u"authorizing":
match = child.expect([pexpect.EOF,
u"(?i)timeout, server not responding",
u"(?i)pass(word|phrase .*):",
u"(?i)permission denied",
u"authenticity"])
log.Debug(u"State = %s, Before = '%s'" % (state, child.before.strip()))
if match == 0:
log.Warn(u"Failed to authenticate")
break
elif match == 1:
log.Warn(u"Timeout waiting to authenticate")
break
elif match == 2:
child.sendline(self.password)
state = u"copying"
elif match == 3:
log.Warn(u"Invalid SSH password")
break
elif match == 4:
log.Warn(u"Remote host authentication failed (missing known_hosts entry?)")
break
elif state == u"copying":
match = child.expect([pexpect.EOF,
u"(?i)timeout, server not responding",
u"stalled",
u"authenticity",
u"ETA"])
log.Debug(u"State = %s, Before = '%s'" % (state, child.before.strip()))
if match == 0:
break
elif match == 1:
log.Warn(u"Timeout waiting for response")
break
elif match == 2:
state = u"stalled"
elif match == 3:
log.Warn(u"Remote host authentication failed (missing known_hosts entry?)")
break
elif state == u"stalled":
match = child.expect([pexpect.EOF,
u"(?i)timeout, server not responding",
u"ETA"])
log.Debug(u"State = %s, Before = '%s'" % (state, child.before.strip()))
if match == 0:
break
elif match == 1:
log.Warn(u"Stalled for too long, aborted copy")
break
elif match == 2:
state = u"copying"
child.close(force=True)
if child.exitstatus != 0:
raise BackendException(u"Error running '%s'" % commandline)
[docs] def run_sftp_command(self, commandline, commands):
u""" Run an sftp command, responding to password prompts, passing commands from list """
maxread = 2000 # expected read buffer size
responses = [pexpect.EOF,
u"(?i)timeout, server not responding",
u"sftp>",
u"(?i)pass(word|phrase .*):",
u"(?i)permission denied",
u"authenticity",
u"(?i)no such file or directory",
u"Couldn't delete file: No such file or directory",
u"Couldn't delete file",
u"open(.*): Failure"]
max_response_len = max([len(p) for p in responses[1:]])
log.Info(u"Running '%s'" % (commandline))
child = pexpect.spawn(commandline, timeout=None, maxread=maxread, encoding=config.fsencoding, use_poll=True)
cmdloc = 0
passprompt = 0
while 1:
msg = u""
match = child.expect(responses,
searchwindowsize=maxread + max_response_len)
log.Debug(u"State = sftp, Before = '%s'" % (child.before.strip()))
if match == 0:
break
elif match == 1:
msg = u"Timeout waiting for response"
break
if match == 2:
if cmdloc < len(commands):
command = commands[cmdloc]
log.Info(u"sftp command: '%s'" % (command,))
child.sendline(command)
cmdloc += 1
else:
command = u'quit'
child.sendline(command)
res = child.before
elif match == 3:
passprompt += 1
child.sendline(self.password)
if (passprompt > 1):
raise BackendException(u"Invalid SSH password.")
elif match == 4:
if not child.before.strip().startswith(u"mkdir"):
msg = u"Permission denied"
break
elif match == 5:
msg = u"Host key authenticity could not be verified (missing known_hosts entry?)"
break
elif match == 6:
if not child.before.strip().startswith(u"rm"):
msg = u"Remote file or directory does not exist in command='%s'" % (commandline,)
break
elif match == 7:
if not child.before.strip().startswith(u"Removing"):
msg = u"Could not delete file in command='%s'" % (commandline,)
break
elif match == 8:
msg = u"Could not delete file in command='%s'" % (commandline,)
break
elif match == 9:
msg = u"Could not open file in command='%s'" % (commandline,)
break
child.close(force=True)
if child.exitstatus == 0:
return res
else:
raise BackendException(u"Error running '%s': %s" % (commandline, msg))
[docs] def _put(self, source_path, remote_filename):
remote_filename = util.fsdecode(remote_filename)
if self.use_scp:
self.put_scp(source_path, remote_filename)
else:
self.put_sftp(source_path, remote_filename)
[docs] def put_sftp(self, source_path, remote_filename):
commands = [u"put \"%s\" \"%s.%s.part\"" %
(source_path.uc_name, self.remote_prefix, remote_filename),
u"rename \"%s.%s.part\" \"%s%s\"" %
(self.remote_prefix, remote_filename, self.remote_prefix, remote_filename)]
commandline = (u"%s %s %s" % (self.sftp_command,
config.ssh_options,
self.host_string))
self.run_sftp_command(commandline, commands)
[docs] def put_scp(self, source_path, remote_filename):
commandline = u"%s %s %s %s:%s%s" % \
(self.scp_command, config.ssh_options, source_path.uc_name, self.host_string,
self.remote_prefix, remote_filename)
self.run_scp_command(commandline)
[docs] def _get(self, remote_filename, local_path):
remote_filename = util.fsdecode(remote_filename)
if self.use_scp:
self.get_scp(remote_filename, local_path)
else:
self.get_sftp(remote_filename, local_path)
[docs] def get_sftp(self, remote_filename, local_path):
commands = [u"get \"%s%s\" \"%s\"" %
(self.remote_prefix, remote_filename, local_path.uc_name)]
commandline = (u"%s %s %s" % (self.sftp_command,
config.ssh_options,
self.host_string))
self.run_sftp_command(commandline, commands)
[docs] def get_scp(self, remote_filename, local_path):
commandline = u"%s %s %s:%s%s %s" % \
(self.scp_command, config.ssh_options, self.host_string, self.remote_prefix,
remote_filename, local_path.uc_name)
self.run_scp_command(commandline)
[docs] def _list(self):
# Note that this command can get confused when dealing with
# files with newlines in them, as the embedded newlines cannot
# be distinguished from the file boundaries.
dirs = self.remote_dir.split(os.sep)
if len(dirs) > 0:
if dirs[0] == u'':
dirs[0] = u'/'
mkdir_commands = []
for d in dirs:
mkdir_commands += [u"mkdir \"%s\"" % (d)] + [u"cd \"%s\"" % (d)]
commands = mkdir_commands + [u"ls -1"]
commandline = (u"%s %s %s" % (self.sftp_command,
config.ssh_options,
self.host_string))
l = self.run_sftp_command(commandline, commands).split(u'\n')[1:]
return [x for x in map(u"".__class__.strip, l) if x]
[docs] def _delete(self, filename):
commands = [u"cd \"%s\"" % (self.remote_dir,)]
commands.append(u"rm \"%s\"" % util.fsdecode(filename))
commandline = (u"%s %s %s" % (self.sftp_command, config.ssh_options, self.host_string))
self.run_sftp_command(commandline, commands)
[docs] def _delete_list(self, filename_list):
commands = [u"cd \"%s\"" % (self.remote_dir,)]
for filename in filename_list:
commands.append(u"rm \"%s\"" % util.fsdecode(filename))
commandline = (u"%s %s %s" % (self.sftp_command, config.ssh_options, self.host_string))
self.run_sftp_command(commandline, commands)
duplicity.backend.register_backend(u"pexpect+sftp", SSHPExpectBackend)
duplicity.backend.register_backend(u"pexpect+scp", SSHPExpectBackend)
duplicity.backend.uses_netloc.extend([u'pexpect+sftp', u'pexpect+scp'])