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]
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
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 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. This flag, along with the -p flag, may be used to disable
operations that are irrelevant or undesirable for the server.
For example, a sftp-server that accepts connections from
untrusted clients may wish to disable the "copy-data" or
"users-groups-by-id" operations.
-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.
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>
Darwin 24.6.0 May 21, 2026 Darwin 24.6.0
openssh 10.5p1 - Generated Tue Aug 25 15:57:22 CDT 2026