sftp-server --- SFTP server subsystem


     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


     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

     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,
         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


     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 markus@openbsd.org


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