diff options
Diffstat (limited to 'sshd.8')
-rw-r--r-- | sshd.8 | 73 |
1 files changed, 56 insertions, 17 deletions
@@ -34,8 +34,8 @@ | |||
34 | .\" (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF | 34 | .\" (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF |
35 | .\" THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. | 35 | .\" THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. |
36 | .\" | 36 | .\" |
37 | .\" $OpenBSD: sshd.8,v 1.237 2007/06/07 19:37:34 pvalchev Exp $ | 37 | .\" $OpenBSD: sshd.8,v 1.246 2008/07/02 02:24:18 djm Exp $ |
38 | .Dd $Mdocdate: August 16 2007 $ | 38 | .Dd $Mdocdate: July 2 2008 $ |
39 | .Dt SSHD 8 | 39 | .Dt SSHD 8 |
40 | .Os | 40 | .Os |
41 | .Sh NAME | 41 | .Sh NAME |
@@ -44,8 +44,9 @@ | |||
44 | .Sh SYNOPSIS | 44 | .Sh SYNOPSIS |
45 | .Nm sshd | 45 | .Nm sshd |
46 | .Bk -words | 46 | .Bk -words |
47 | .Op Fl 46Ddeiqt | 47 | .Op Fl 46DdeiqTt |
48 | .Op Fl b Ar bits | 48 | .Op Fl b Ar bits |
49 | .Op Fl C Ar connection_spec | ||
49 | .Op Fl f Ar config_file | 50 | .Op Fl f Ar config_file |
50 | .Op Fl g Ar login_grace_time | 51 | .Op Fl g Ar login_grace_time |
51 | .Op Fl h Ar host_key_file | 52 | .Op Fl h Ar host_key_file |
@@ -99,7 +100,25 @@ Forces | |||
99 | to use IPv6 addresses only. | 100 | to use IPv6 addresses only. |
100 | .It Fl b Ar bits | 101 | .It Fl b Ar bits |
101 | Specifies the number of bits in the ephemeral protocol version 1 | 102 | Specifies the number of bits in the ephemeral protocol version 1 |
102 | server key (default 768). | 103 | server key (default 1024). |
104 | .It Fl C Ar connection_spec | ||
105 | Specify the connection parameters to use for the | ||
106 | .Fl T | ||
107 | extended test mode. | ||
108 | If provided, any | ||
109 | .Cm Match | ||
110 | directives in the configuration file | ||
111 | that would apply to the specified user, host, and address will be set before | ||
112 | the configuration is written to standard output. | ||
113 | The connection parameters are supplied as keyword=value pairs. | ||
114 | The keywords are | ||
115 | .Dq user , | ||
116 | .Dq host , | ||
117 | and | ||
118 | .Dq addr . | ||
119 | All are required and may be supplied in any order, either with multiple | ||
120 | .Fl C | ||
121 | options or as a comma-separated list. | ||
103 | .It Fl D | 122 | .It Fl D |
104 | When this option is specified, | 123 | When this option is specified, |
105 | .Nm | 124 | .Nm |
@@ -194,6 +213,15 @@ authentication, and termination of each connection is logged. | |||
194 | If a second | 213 | If a second |
195 | .Fl q | 214 | .Fl q |
196 | is given then nothing is sent to the system log. | 215 | is given then nothing is sent to the system log. |
216 | .It Fl T | ||
217 | Extended test mode. | ||
218 | Check the validity of the configuration file, output the effective configuration | ||
219 | to stdout and then exit. | ||
220 | Optionally, | ||
221 | .Cm Match | ||
222 | rules may be applied by specifying the connection parameters using one or more | ||
223 | .Fl C | ||
224 | options. | ||
197 | .It Fl t | 225 | .It Fl t |
198 | Test mode. | 226 | Test mode. |
199 | Only check the validity of the configuration file and sanity of the keys. | 227 | Only check the validity of the configuration file and sanity of the keys. |
@@ -506,23 +534,27 @@ This option is automatically disabled if | |||
506 | .Cm UseLogin | 534 | .Cm UseLogin |
507 | is enabled. | 535 | is enabled. |
508 | .It Cm from="pattern-list" | 536 | .It Cm from="pattern-list" |
509 | Specifies that in addition to public key authentication, the canonical name | 537 | Specifies that in addition to public key authentication, either the canonical |
510 | of the remote host must be present in the comma-separated list of | 538 | name of the remote host or its IP address must be present in the |
511 | patterns. | 539 | comma-separated list of patterns. |
512 | The purpose | ||
513 | of this option is to optionally increase security: public key authentication | ||
514 | by itself does not trust the network or name servers or anything (but | ||
515 | the key); however, if somebody somehow steals the key, the key | ||
516 | permits an intruder to log in from anywhere in the world. | ||
517 | This additional option makes using a stolen key more difficult (name | ||
518 | servers and/or routers would have to be compromised in addition to | ||
519 | just the key). | ||
520 | .Pp | ||
521 | See | 540 | See |
522 | .Sx PATTERNS | 541 | .Sx PATTERNS |
523 | in | 542 | in |
524 | .Xr ssh_config 5 | 543 | .Xr ssh_config 5 |
525 | for more information on patterns. | 544 | for more information on patterns. |
545 | .Pp | ||
546 | In addition to the wildcard matching that may be applied to hostnames or | ||
547 | addresses, a | ||
548 | .Cm from | ||
549 | stanza may match IP addressess using CIDR address/masklen notation. | ||
550 | .Pp | ||
551 | The purpose of this option is to optionally increase security: public key | ||
552 | authentication by itself does not trust the network or name servers or | ||
553 | anything (but the key); however, if somebody somehow steals the key, the key | ||
554 | permits an intruder to log in from anywhere in the world. | ||
555 | This additional option makes using a stolen key more difficult (name | ||
556 | servers and/or routers would have to be compromised in addition to | ||
557 | just the key). | ||
526 | .It Cm no-agent-forwarding | 558 | .It Cm no-agent-forwarding |
527 | Forbids authentication agent forwarding when this key is used for | 559 | Forbids authentication agent forwarding when this key is used for |
528 | authentication. | 560 | authentication. |
@@ -535,7 +567,7 @@ option. | |||
535 | .It Cm no-pty | 567 | .It Cm no-pty |
536 | Prevents tty allocation (a request to allocate a pty will fail). | 568 | Prevents tty allocation (a request to allocate a pty will fail). |
537 | .It Cm no-user-rc | 569 | .It Cm no-user-rc |
538 | Disables execution of | 570 | Disables execution of |
539 | .Pa ~/.ssh/rc . | 571 | .Pa ~/.ssh/rc . |
540 | .It Cm no-X11-forwarding | 572 | .It Cm no-X11-forwarding |
541 | Forbids X11 forwarding when this key is used for authentication. | 573 | Forbids X11 forwarding when this key is used for authentication. |
@@ -688,6 +720,13 @@ This file is used in exactly the same way as | |||
688 | but allows host-based authentication without permitting login with | 720 | but allows host-based authentication without permitting login with |
689 | rlogin/rsh. | 721 | rlogin/rsh. |
690 | .Pp | 722 | .Pp |
723 | .It ~/.ssh/ | ||
724 | This directory is the default location for all user-specific configuration | ||
725 | and authentication information. | ||
726 | There is no general requirement to keep the entire contents of this directory | ||
727 | secret, but the recommended permissions are read/write/execute for the user, | ||
728 | and not accessible by others. | ||
729 | .Pp | ||
691 | .It ~/.ssh/authorized_keys | 730 | .It ~/.ssh/authorized_keys |
692 | Lists the public keys (RSA/DSA) that can be used for logging in as this user. | 731 | Lists the public keys (RSA/DSA) that can be used for logging in as this user. |
693 | The format of this file is described above. | 732 | The format of this file is described above. |