SFTP-SERVER(8) Maintenance Commands and Procedures 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_featureDESCRIPTION
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.
-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>
illumos July 27, 2021 illumos