sftp-server

SFTP-SERVER(8)            BSD 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 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 in-
     tended to be called directly, but from sshd(8) using the Subsystem op-
     tion.

     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 path-
             name may contain the following tokens that are expanded at run-
             time: %% 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 pos-
             sible values are: QUIET, FATAL, ERROR, INFO, VERBOSE, DEBUG, DE-
             BUG1, 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 re-
             quests 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.  At-
             tempts 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 re-
     quires that syslogd(8) establish a logging socket inside the chroot di-
     rectory.

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>

BSD                            November 30, 2019                           BSD