NAME¶
sftp-server
—
SFTP server subsystem
SYNOPSIS¶
sftp-server |
[ -ehR ]
[-d start_directory ]
[-f log_facility ]
[-l log_level ]
[-P blacklisted_requests ]
[-p whitelisted_requests ]
[-u umask ] |
sftp-server |
-Q
protocol_feature |
DESCRIPTION¶
sftp-server
is a program that speaks the
server side of SFTP protocol to stdout and expects client requests from stdin.
sftp-server
is not intended to be called
directly, but from
sshd(8) using the
Subsystem
option.
Command-line flags to
sftp-server
should be
specified in the
Subsystem
declaration. See
sshd_config(5) for more information.
Valid options are:
-d
start_directory
- specifies an alternate starting directory for users. The pathname may
contain the following tokens that are expanded at runtime: %% is replaced
by a literal '%', %h is replaced by the home directory of the user being
authenticated, and %u is replaced by the username of that user. The
default is to use the user's home directory. This option is useful in
conjunction with the sshd_config(5)
ChrootDirectory
option.
-e
- Causes
sftp-server
to print logging
information to stderr instead of syslog for debugging.
-f
log_facility
- Specifies the facility code that is used when logging messages from
sftp-server
. The possible values are:
DAEMON, USER, AUTH, LOCAL0, LOCAL1, LOCAL2, LOCAL3, LOCAL4, LOCAL5,
LOCAL6, LOCAL7. The default is AUTH.
-h
- Displays
sftp-server
usage
information.
-l
log_level
- Specifies which messages will be logged by
sftp-server
. The possible values are:
QUIET, FATAL, ERROR, INFO, VERBOSE, DEBUG, DEBUG1, DEBUG2, and DEBUG3.
INFO and VERBOSE log transactions that
sftp-server
performs on behalf of the
client. DEBUG and DEBUG1 are equivalent. DEBUG2 and DEBUG3 each specify
higher levels of debugging output. The default is ERROR.
-P
blacklisted_requests
- Specify a comma-separated list of SFTP protocol requests that are banned
by the server.
sftp-server
will reply
to any blacklisted request with a failure. The
-Q
flag can be used to determine the
supported request types. If both a blacklist and a whitelist are
specified, then the blacklist is applied before the whitelist.
-p
whitelisted_requests
- Specify a comma-separated list of SFTP protocol requests that are
permitted by the server. All request types that are not on the whitelist
will be logged and replied to with a failure message.
Care must be taken when using this feature to ensure that requests made
implicitly by SFTP clients are permitted.
-Q
protocol_feature
- Query protocol features supported by
sftp-server
. At present the only
feature that may be queried is “requests”, which may be used
for black or whitelisting (flags -P
and
-p
respectively).
-R
- Places this instance of
sftp-server
into a read-only mode. Attempts to open files for writing, as well as
other operations that change the state of the filesystem, will be
denied.
-u
umask
- Sets an explicit umask(2) to be applied to
newly-created files and directories, instead of the user's default
mask.
On some systems,
sftp-server
must be able to
access
/dev/log for logging to work, and
use of
sftp-server
in a chroot
configuration therefore requires that
syslogd(8)
establish a logging socket inside the chroot directory.
SEE ALSO¶
sftp(1),
ssh(1),
sshd_config(5),
sshd(8)
T. Ylonen and
S. Lehtinen, SSH File Transfer
Protocol, draft-ietf-secsh-filexfer-02.txt,
October 2001, work in progress
material.
HISTORY¶
sftp-server
first appeared in
OpenBSD 2.8.
AUTHORS¶
Markus Friedl
<
markus@openbsd.org>