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 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 requests 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. 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.