=================================================================== RCS file: /cvsrepo/anoncvs/cvs/src/usr.bin/ssh/sshd.8,v retrieving revision 1.200 retrieving revision 1.200.2.2 diff -u -r1.200 -r1.200.2.2 --- src/usr.bin/ssh/sshd.8 2003/10/08 08:27:36 1.200 +++ src/usr.bin/ssh/sshd.8 2005/03/10 17:15:05 1.200.2.2 @@ -34,7 +34,7 @@ .\" (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF .\" THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. .\" -.\" $OpenBSD: sshd.8,v 1.200 2003/10/08 08:27:36 jmc Exp $ +.\" $OpenBSD: sshd.8,v 1.200.2.2 2005/03/10 17:15:05 brad Exp $ .Dd September 25, 1999 .Dt SSHD 8 .Os @@ -106,16 +106,10 @@ Next, the server and the client enter an authentication dialog. The client tries to authenticate itself using .Em rhosts -authentication, -.Em rhosts authentication combined with RSA host authentication, RSA challenge-response authentication, or password based authentication. .Pp -.Em rhosts -authentication is normally disabled -because it is fundamentally insecure, but can be enabled in the server -configuration file if desired. System security is not improved unless .Nm rshd , .Nm rlogind , @@ -173,7 +167,7 @@ .Nm rereads its configuration file when it receives a hangup signal, .Dv SIGHUP , -by executing itself with the name it was started as, i.e., +by executing itself with the name and options it was started with, e.g., .Pa /usr/sbin/sshd . .Pp The options are as follows: @@ -404,7 +398,9 @@ .Dq ssh-rsa . .Pp Note that lines in this file are usually several hundred bytes long -(because of the size of the public key encoding). +(because of the size of the public key encoding) up to a limit of +8 kilobytes, which permits DSA keys up to 8 kilobits and RSA +keys up to 16 kilobits. You don't want to type them in; instead, copy the .Pa identity.pub , .Pa id_dsa.pub @@ -535,6 +531,14 @@ pattern, it is not accepted (by that line) even if it matched another pattern on the line. .Pp +Alternately, hostnames may be stored in a hashed form which hides host names +and addresses should the file's contents be disclosed. +Hashed hostnames start with a +.Ql | +character. +Only one hashed hostname may appear on a single line and none of the above +negation or wildcard operators may be applied. +.Pp Bits, exponent, and modulus are taken directly from the RSA host key; they can be obtained, e.g., from .Pa /etc/ssh/ssh_host_key.pub . @@ -566,6 +570,11 @@ closenet,...,130.233.208.41 1024 37 159...93 closenet.hut.fi cvs.openbsd.org,199.185.137.3 ssh-rsa AAAA1234.....= .Ed +.Bd -literal +# A hashed hostname +|1|JfKTdBh7rNbXkVAQCRp4OQoPfmI=|USECr3SWf1JUPsms5AqfD5QfxkM= ssh-rsa +AAAA1234.....= +.Ed .Sh FILES .Bl -tag -width Ds .It Pa /etc/ssh/sshd_config @@ -634,6 +643,20 @@ should be world-readable, and .Pa $HOME/.ssh/known_hosts can, but need not be, world-readable. +.It Pa /etc/motd +See +.Xr motd 5 . +.It Pa $HOME/.hushlogin +This file is used to suppress printing the last login time and +.Pa /etc/motd , +if +.Cm PrintLastLog +and +.Cm PrintMotd , +respectively, +are enabled. +It does not suppress printing of the banner specified by +.Cm Banner . .It Pa /etc/nologin If this file exists, .Nm @@ -647,7 +670,11 @@ Further details are described in .Xr hosts_access 5 . .It Pa $HOME/.rhosts -This file contains host-username pairs, separated by a space, one per +This file is used during +.Cm RhostsRSAAuthentication +and +.Cm HostbasedAuthentication +and contains host-username pairs, separated by a space, one per line. The given user on the corresponding host is permitted to log in without a password. @@ -668,7 +695,9 @@ not used by rlogin and rshd, so using this permits access using SSH only. .It Pa /etc/hosts.equiv This file is used during -.Em rhosts +.Cm RhostsRSAAuthentication +and +.Cm HostbasedAuthentication authentication. In the simplest form, this file contains host names, one per line. Users on @@ -687,7 +716,7 @@ If the client host/user is successfully matched in this file, login is automatically permitted provided the client and server user names are the same. -Additionally, successful RSA host authentication is normally required. +Additionally, successful client host key authentication is required. This file must be writable only by root; it is recommended that it be world-readable. .Pp