sftp-server —
OpenSSH SFTP server subsystem
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
|
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.
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.
sftp-server first appeared in
OpenBSD 2.8.
Markus Friedl
<
[email protected]>