1SFTP-SERVER(8) BSD System Manager's Manual SFTP-SERVER(8)
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4 sftp-server — SFTP server subsystem
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7 sftp-server [-ehR] [-d start_directory] [-f log_facility] [-l log_level]
8 [-P blacklisted_requests] [-p whitelisted_requests]
9 [-u umask] [-m force_file_perms]
10 sftp-server -Q protocol_feature
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13 sftp-server is a program that speaks the server side of SFTP protocol to
14 stdout and expects client requests from stdin. sftp-server is not
15 intended to be called directly, but from sshd(8) using the Subsystem
16 option.
17 Command-line flags to sftp-server should be specified in the Subsystem
19 declaration. See sshd_config(5) for more information.
20 Valid options are:
22 -d start_directory
24 specifies an alternate starting directory for users. The path‐
25 name may contain the following tokens that are expanded at run‐
26 time: %% is replaced by a literal '%', %d is replaced by the home
27 directory of the user being authenticated, and %u is replaced by
28 the username of that user. The default is to use the user's home
29 directory. This option is useful in conjunction with the
30 sshd_config(5) ChrootDirectory option.
31 -e Causes sftp-server to print logging information to stderr instead
33 of syslog for debugging.
34 -f log_facility
36 Specifies the facility code that is used when logging messages
37 from sftp-server. The possible values are: DAEMON, USER, AUTH,
38 LOCAL0, LOCAL1, LOCAL2, LOCAL3, LOCAL4, LOCAL5, LOCAL6, LOCAL7.
39 The default is AUTH.
40 -h Displays sftp-server usage information.
42 -l log_level
44 Specifies which messages will be logged by sftp-server. The pos‐
45 sible values are: QUIET, FATAL, ERROR, INFO, VERBOSE, DEBUG,
46 DEBUG1, DEBUG2, and DEBUG3. INFO and VERBOSE log transactions
47 that sftp-server performs on behalf of the client. DEBUG and
48 DEBUG1 are equivalent. DEBUG2 and DEBUG3 each specify higher
49 levels of debugging output. The default is ERROR.
50 -P blacklisted_requests
52 Specify a comma-separated list of SFTP protocol requests that are
53 banned by the server. sftp-server will reply to any blacklisted
54 request with a failure. The -Q flag can be used to determine the
55 supported request types. If both a blacklist and a whitelist are
56 specified, then the blacklist is applied before the whitelist.
57 -p whitelisted_requests
59 Specify a comma-separated list of SFTP protocol requests that are
60 permitted by the server. All request types that are not on the
61 whitelist will be logged and replied to with a failure message.
62 Care must be taken when using this feature to ensure that
64 requests made implicitly by SFTP clients are permitted.
65 -Q protocol_feature
67 Query protocol features supported by sftp-server. At present the
68 only feature that may be queried is “requests”, which may be used
69 for black or whitelisting (flags -P and -p respectively).
70 -R Places this instance of sftp-server into a read-only mode.
72 Attempts to open files for writing, as well as other operations
73 that change the state of the filesystem, will be denied.
74 -u umask
76 Sets an explicit umask(2) to be applied to newly-created files
77 and directories, instead of the user's default mask.
78 -m force_file_perms
80 Sets explicit file permissions to be applied to newly-created
81 files instead of the default or client requested mode. Numeric
82 values include: 777, 755, 750, 666, 644, 640, etc. Option -u is
83 ineffective if -m is set.
84 On some systems, sftp-server must be able to access /dev/log for logging
86 to work, and use of sftp-server in a chroot configuration therefore
87 requires that syslogd(8) establish a logging socket inside the chroot
88 directory.
89
91 sftp(1), ssh(1), sshd_config(5), sshd(8)
92 T. Ylonen and S. Lehtinen, SSH File Transfer Protocol, draft-ietf-secsh-
94 filexfer-02.txt, October 2001, work in progress material.
95
97 sftp-server first appeared in OpenBSD 2.8.
98
100 Markus Friedl <markus@openbsd.org>
101BSD June 20, 2019 BSD