SFTP-SERVER(8) | System Manager's Manual | SFTP-SERVER(8) |
NAME¶
sftp-server
—
OpenSSH SFTP server subsystem
SYNOPSIS¶
sftp-server |
[-ehR ]
[-d start_directory]
[-f log_facility]
[-l log_level]
[-P denied_requests]
[-p allowed_requests]
[-u umask]
[-m force_file_dir_perms] |
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 '%', %d 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 thatsftp-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
denied_requests- Specifies a comma-separated list of SFTP protocol requests that are banned
by the server.
sftp-server
will reply to any denied request with a failure. The-Q
flag can be used to determine the supported request types. If both denied and allowed lists are specified, then the denied list is applied before the allowed list. -p
allowed_requests- Specifies a comma-separated list of SFTP protocol requests that are
permitted by the server. All request types that are not on the allowed
list 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- Queries protocol features supported by
sftp-server
. At present the only feature that may be queried is “requests”, which may be used to deny or allow specific requests (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.
-m
force_file_dir_perms- Sets explicit permissions to be applied to newly-created files and directories instead of the default or client requested mode. Numeric values include: 777, 755, 750, 666, 644, 640, etc. Option -u is ineffective if -m is set.
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>
July 27, 2021 | Linux 6.4.0-150600.23.25-default |