sftp-server (8) - Linux Manuals

sftp-server: OpenSSH SFTP server subsystem


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_config5 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_config5 ChrootDirectory option.
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.
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).
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-server first appeared in Ox 2.8 .


An Markus Friedl Aq Mt markus [at] openbsd.org


sftp(1), ssh(1), sshd_config5, sshd(8)
T. Ylonen S. Lehtinen "SSH File Transfer Protocol" draft-ietf-secsh-filexfer-02.txt October 2001 work in progress material