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authorjmc@openbsd.org <jmc@openbsd.org>2016-02-17 07:38:19 +0000
committerDamien Miller <djm@mindrot.org>2016-02-18 09:24:40 +1100
commita685ae8d1c24fb7c712c55a4f3280ee76f5f1e4b (patch)
treee584cc9a85e18c54887ca626295a6222d075e6ae /ssh.1
parentc5c3f3279a0e4044b8de71b70d3570d692d0f29d (diff)
upstream commit
since these pages now clearly tell folks to avoid v1, normalise the docs from a v2 perspective (i.e. stop pointing out which bits are v2 only); ok/tweaks djm ok markus Upstream-ID: eb474f8c36fb6a532dc05c282f7965e38dcfa129
Diffstat (limited to 'ssh.1')
-rw-r--r--ssh.166
1 files changed, 24 insertions, 42 deletions
diff --git a/ssh.1 b/ssh.1
index afc3537b0..cc5334338 100644
--- a/ssh.1
+++ b/ssh.1
@@ -33,8 +33,8 @@
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: ssh.1,v 1.368 2016/02/16 07:47:54 jmc Exp $ 36.\" $OpenBSD: ssh.1,v 1.369 2016/02/17 07:38:19 jmc Exp $
37.Dd $Mdocdate: February 16 2016 $ 37.Dd $Mdocdate: February 17 2016 $
38.Dt SSH 1 38.Dt SSH 1
39.Os 39.Os
40.Sh NAME 40.Sh NAME
@@ -402,17 +402,15 @@ in
402for details. 402for details.
403.Pp 403.Pp
404.It Fl m Ar mac_spec 404.It Fl m Ar mac_spec
405Additionally, for protocol version 2 a comma-separated list of MAC 405A comma-separated list of MAC (message authentication code) algorithms,
406(message authentication code) algorithms can 406specified in order of preference.
407be specified in order of preference.
408See the 407See the
409.Cm MACs 408.Cm MACs
410keyword for more information. 409keyword for more information.
411.Pp 410.Pp
412.It Fl N 411.It Fl N
413Do not execute a remote command. 412Do not execute a remote command.
414This is useful for just forwarding ports 413This is useful for just forwarding ports.
415(protocol version 2 only).
416.Pp 414.Pp
417.It Fl n 415.It Fl n
418Redirects stdin from 416Redirects stdin from
@@ -664,8 +662,8 @@ for details.
664.Pp 662.Pp
665.It Fl s 663.It Fl s
666May be used to request invocation of a subsystem on the remote system. 664May be used to request invocation of a subsystem on the remote system.
667Subsystems are a feature of the SSH2 protocol which facilitate the use 665Subsystems facilitate the use of SSH
668of SSH as a secure transport for other applications (eg.\& 666as a secure transport for other applications (e.g.\&
669.Xr sftp 1 ) . 667.Xr sftp 1 ) .
670The subsystem is specified as the remote command. 668The subsystem is specified as the remote command.
671.Pp 669.Pp
@@ -710,7 +708,6 @@ Implies
710.Cm ExitOnForwardFailure 708.Cm ExitOnForwardFailure
711and 709and
712.Cm ClearAllForwardings . 710.Cm ClearAllForwardings .
713Works with Protocol version 2 only.
714.Pp 711.Pp
715.It Fl w Xo 712.It Fl w Xo
716.Ar local_tun Ns Op : Ns Ar remote_tun 713.Ar local_tun Ns Op : Ns Ar remote_tun
@@ -795,8 +792,10 @@ or the
795and 792and
796.Fl 2 793.Fl 2
797options (see above). 794options (see above).
798Protocol 1 should not be used - it suffers from a number of cryptographic 795Protocol 1 should not be used
799weaknesses and is only offered to support legacy devices. 796and is only offered to support legacy devices.
797It suffers from a number of cryptographic weaknesses
798and doesn't support many of the advanced features available for protocol 2.
800.Pp 799.Pp
801The methods available for authentication are: 800The methods available for authentication are:
802GSSAPI-based authentication, 801GSSAPI-based authentication,
@@ -805,8 +804,9 @@ public key authentication,
805challenge-response authentication, 804challenge-response authentication,
806and password authentication. 805and password authentication.
807Authentication methods are tried in the order specified above, 806Authentication methods are tried in the order specified above,
808though protocol 2 has a configuration option to change the default order: 807though
809.Cm PreferredAuthentications . 808.Cm PreferredAuthentications
809can be used to change the default order.
810.Pp 810.Pp
811Host-based authentication works as follows: 811Host-based authentication works as follows:
812If the machine the user logs in from is listed in 812If the machine the user logs in from is listed in
@@ -850,8 +850,6 @@ The server knows the public key, and only the user knows the private key.
850.Nm 850.Nm
851implements public key authentication protocol automatically, 851implements public key authentication protocol automatically,
852using one of the DSA, ECDSA, Ed25519 or RSA algorithms. 852using one of the DSA, ECDSA, Ed25519 or RSA algorithms.
853Protocol 1 is restricted to using only RSA keys,
854but protocol 2 may use any.
855The HISTORY section of 853The HISTORY section of
856.Xr ssl 8 854.Xr ssl 8
857contains a brief discussion of the DSA and RSA algorithms. 855contains a brief discussion of the DSA and RSA algorithms.
@@ -873,26 +871,26 @@ This stores the private key in
873.Pa ~/.ssh/identity 871.Pa ~/.ssh/identity
874(protocol 1), 872(protocol 1),
875.Pa ~/.ssh/id_dsa 873.Pa ~/.ssh/id_dsa
876(protocol 2 DSA), 874(DSA),
877.Pa ~/.ssh/id_ecdsa 875.Pa ~/.ssh/id_ecdsa
878(protocol 2 ECDSA), 876(ECDSA),
879.Pa ~/.ssh/id_ed25519 877.Pa ~/.ssh/id_ed25519
880(protocol 2 Ed25519), 878(Ed25519),
881or 879or
882.Pa ~/.ssh/id_rsa 880.Pa ~/.ssh/id_rsa
883(protocol 2 RSA) 881(RSA)
884and stores the public key in 882and stores the public key in
885.Pa ~/.ssh/identity.pub 883.Pa ~/.ssh/identity.pub
886(protocol 1), 884(protocol 1),
887.Pa ~/.ssh/id_dsa.pub 885.Pa ~/.ssh/id_dsa.pub
888(protocol 2 DSA), 886(DSA),
889.Pa ~/.ssh/id_ecdsa.pub 887.Pa ~/.ssh/id_ecdsa.pub
890(protocol 2 ECDSA), 888(ECDSA),
891.Pa ~/.ssh/id_ed25519.pub 889.Pa ~/.ssh/id_ed25519.pub
892(protocol 2 Ed25519), 890(Ed25519),
893or 891or
894.Pa ~/.ssh/id_rsa.pub 892.Pa ~/.ssh/id_rsa.pub
895(protocol 2 RSA) 893(RSA)
896in the user's home directory. 894in the user's home directory.
897The user should then copy the public key 895The user should then copy the public key
898to 896to
@@ -930,8 +928,6 @@ Challenge-response authentication works as follows:
930The server sends an arbitrary 928The server sends an arbitrary
931.Qq challenge 929.Qq challenge
932text, and prompts for a response. 930text, and prompts for a response.
933Protocol 2 allows multiple challenges and responses;
934protocol 1 is restricted to just one challenge/response.
935Examples of challenge-response authentication include 931Examples of challenge-response authentication include
936.Bx 932.Bx
937Authentication (see 933Authentication (see
@@ -1030,7 +1026,7 @@ at logout when waiting for forwarded connection / X11 sessions to terminate.
1030Display a list of escape characters. 1026Display a list of escape characters.
1031.It Cm ~B 1027.It Cm ~B
1032Send a BREAK to the remote system 1028Send a BREAK to the remote system
1033(only useful for SSH protocol version 2 and if the peer supports it). 1029(only useful if the peer supports it).
1034.It Cm ~C 1030.It Cm ~C
1035Open command line. 1031Open command line.
1036Currently this allows the addition of port forwardings using the 1032Currently this allows the addition of port forwardings using the
@@ -1063,7 +1059,7 @@ Basic help is available, using the
1063option. 1059option.
1064.It Cm ~R 1060.It Cm ~R
1065Request rekeying of the connection 1061Request rekeying of the connection
1066(only useful for SSH protocol version 2 and if the peer supports it). 1062(only useful if the peer supports it).
1067.It Cm ~V 1063.It Cm ~V
1068Decrease the verbosity 1064Decrease the verbosity
1069.Pq Ic LogLevel 1065.Pq Ic LogLevel
@@ -1531,20 +1527,6 @@ The file format and configuration options are described in
1531.It Pa /etc/ssh/ssh_host_rsa_key 1527.It Pa /etc/ssh/ssh_host_rsa_key
1532These files contain the private parts of the host keys 1528These files contain the private parts of the host keys
1533and are used for host-based authentication. 1529and are used for host-based authentication.
1534If protocol version 1 is used,
1535.Nm
1536must be setuid root, since the host key is readable only by root.
1537For protocol version 2,
1538.Nm
1539uses
1540.Xr ssh-keysign 8
1541to access the host keys,
1542eliminating the requirement that
1543.Nm
1544be setuid root when host-based authentication is used.
1545By default
1546.Nm
1547is not setuid root.
1548.Pp 1530.Pp
1549.It Pa /etc/ssh/ssh_known_hosts 1531.It Pa /etc/ssh/ssh_known_hosts
1550Systemwide list of known host keys. 1532Systemwide list of known host keys.