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-rw-r--r--sshd.864
1 files changed, 42 insertions, 22 deletions
diff --git a/sshd.8 b/sshd.8
index fb133c14b..c5f8987d2 100644
--- a/sshd.8
+++ b/sshd.8
@@ -33,13 +33,13 @@
33.\" (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF 33.\" (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
34.\" THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 34.\" THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
35.\" 35.\"
36.\" $OpenBSD: sshd.8,v 1.304 2018/07/22 12:16:59 dtucker Exp $ 36.\" $OpenBSD: sshd.8,v 1.312 2020/01/25 06:03:10 djm Exp $
37.Dd $Mdocdate: July 22 2018 $ 37.Dd $Mdocdate: January 25 2020 $
38.Dt SSHD 8 38.Dt SSHD 8
39.Os 39.Os
40.Sh NAME 40.Sh NAME
41.Nm sshd 41.Nm sshd
42.Nd OpenSSH SSH daemon 42.Nd OpenSSH daemon
43.Sh SYNOPSIS 43.Sh SYNOPSIS
44.Nm sshd 44.Nm sshd
45.Bk -words 45.Bk -words
@@ -253,16 +253,13 @@ Whenever a client connects, the daemon responds with its public
253host key. 253host key.
254The client compares the 254The client compares the
255host key against its own database to verify that it has not changed. 255host key against its own database to verify that it has not changed.
256Forward security is provided through a Diffie-Hellman key agreement. 256Forward secrecy is provided through a Diffie-Hellman key agreement.
257This key agreement results in a shared session key. 257This key agreement results in a shared session key.
258The rest of the session is encrypted using a symmetric cipher, currently 258The rest of the session is encrypted using a symmetric cipher.
259128-bit AES, Blowfish, 3DES, CAST128, Arcfour, 192-bit AES, or 256-bit AES.
260The client selects the encryption algorithm 259The client selects the encryption algorithm
261to use from those offered by the server. 260to use from those offered by the server.
262Additionally, session integrity is provided 261Additionally, session integrity is provided
263through a cryptographic message authentication code 262through a cryptographic message authentication code (MAC).
264(hmac-md5, hmac-sha1, umac-64, umac-128,
265hmac-sha2-256 or hmac-sha2-512).
266.Pp 263.Pp
267Finally, the server and the client enter an authentication dialog. 264Finally, the server and the client enter an authentication dialog.
268The client tries to authenticate itself using 265The client tries to authenticate itself using
@@ -429,25 +426,39 @@ comments).
429Public keys consist of the following space-separated fields: 426Public keys consist of the following space-separated fields:
430options, keytype, base64-encoded key, comment. 427options, keytype, base64-encoded key, comment.
431The options field is optional. 428The options field is optional.
432The keytype is 429The supported key types are:
433.Dq ecdsa-sha2-nistp256 , 430.Pp
434.Dq ecdsa-sha2-nistp384 , 431.Bl -item -compact -offset indent
435.Dq ecdsa-sha2-nistp521 , 432.It
436.Dq ssh-ed25519 , 433sk-ecdsa-sha2-nistp256@openssh.com
437.Dq ssh-dss 434.It
438or 435ecdsa-sha2-nistp256
439.Dq ssh-rsa ; 436.It
440the comment field is not used for anything (but may be convenient for the 437ecdsa-sha2-nistp384
438.It
439ecdsa-sha2-nistp521
440.It
441sk-ssh-ed25519@openssh.com
442.It
443ssh-ed25519
444.It
445ssh-dss
446.It
447ssh-rsa
448.El
449.Pp
450The comment field is not used for anything (but may be convenient for the
441user to identify the key). 451user to identify the key).
442.Pp 452.Pp
443Note that lines in this file can be several hundred bytes long 453Note that lines in this file can be several hundred bytes long
444(because of the size of the public key encoding) up to a limit of 454(because of the size of the public key encoding) up to a limit of
4458 kilobytes, which permits DSA keys up to 8 kilobits and RSA 4558 kilobytes, which permits RSA keys up to 16 kilobits.
446keys up to 16 kilobits.
447You don't want to type them in; instead, copy the 456You don't want to type them in; instead, copy the
448.Pa id_dsa.pub , 457.Pa id_dsa.pub ,
449.Pa id_ecdsa.pub , 458.Pa id_ecdsa.pub ,
459.Pa id_ecdsa_sk.pub ,
450.Pa id_ed25519.pub , 460.Pa id_ed25519.pub ,
461.Pa id_ed25519_sk.pub ,
451or the 462or the
452.Pa id_rsa.pub 463.Pa id_rsa.pub
453file and edit it. 464file and edit it.
@@ -589,8 +600,8 @@ IPv6 addresses can be specified by enclosing the address in square brackets.
589Multiple 600Multiple
590.Cm permitopen 601.Cm permitopen
591options may be applied separated by commas. 602options may be applied separated by commas.
592No pattern matching is performed on the specified hostnames, 603No pattern matching or name lookup is performed on the
593they must be literal domains or addresses. 604specified hostnames, they must be literal host names and/or addresses.
594A port specification of 605A port specification of
595.Cm * 606.Cm *
596matches any port. 607matches any port.
@@ -613,6 +624,13 @@ option.
613Permits tty allocation previously disabled by the 624Permits tty allocation previously disabled by the
614.Cm restrict 625.Cm restrict
615option. 626option.
627.It Cm no-touch-required
628Do not require demonstration of user presence
629for signatures made using this key.
630This option only makes sense for the FIDO authenticator algorithms
631.Cm ecdsa-sk
632and
633.Cm ed25519-sk .
616.It Cm restrict 634.It Cm restrict
617Enable all restrictions, i.e. disable port, agent and X11 forwarding, 635Enable all restrictions, i.e. disable port, agent and X11 forwarding,
618as well as disabling PTY allocation 636as well as disabling PTY allocation
@@ -656,6 +674,8 @@ restrict,command="uptime" ssh-rsa AAAA1C8...32Tv==
656user@example.net 674user@example.net
657restrict,pty,command="nethack" ssh-rsa AAAA1f8...IrrC5== 675restrict,pty,command="nethack" ssh-rsa AAAA1f8...IrrC5==
658user@example.net 676user@example.net
677no-touch-required sk-ecdsa-sha2-nistp256@openssh.com AAAAInN...Ko==
678user@example.net
659.Ed 679.Ed
660.Sh SSH_KNOWN_HOSTS FILE FORMAT 680.Sh SSH_KNOWN_HOSTS FILE FORMAT
661The 681The