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rlogin.krb5

NAME

rlogin - remote login

SYNOPSIS

rlogin rhost [-ec] [-8] [-c] [ -a] [-f] [-F] [-t termtype] [-n] [-7] [-PN | -PO] [-4] [-d] [-k realm] [-x] [-L] [-l username]

DESCRIPTION

Rlogin connects your terminal on the current local host system lhost to the remote host system rhost.

The version built to use Kerberos authentication is very similar to the standard Berkeley rlogin(1), except that instead of the rhosts mechanism, it uses Kerberos authentication to determine the authorization to use a remote account.

Each user may have a private authorization list in a file .k5login in his login directory. Each line in this file should contain a Kerberos principal name of the form principal/instance@realm. If the originating user is authenticated to one of the principals named in .k5login, access is granted to the account. If there is no /.k5login file, the principal will be granted access to the account according to the aname->lname mapping rules. (See krb5_anadd(8) for more details.) Otherwise a login and password will be prompted for on the remote machine as in login(1). To avoid some security problems, the .k5login file must be owned by the remote user.

If there is some problem in marshaling the Kerberos authentication information, an error message is printed and the standard UCB rlogin is executed in place of the Kerberos rlogin.

A line of the form ``~.'' disconnects from the remote host, where ``~'' is the escape character. Similarly, the line ``~^Z'' (where ^Z, control-Z, is the suspend character) will suspend the rlogin session. Substitution of the delayed-suspend character (normally ^Y) for the suspend character suspends the send portion of the rlogin, but allows output from the remote system.

The remote terminal type is the same as your local terminal type (as given in your environment TERM variable), unless the -t option is specified (see below). The terminal or window size is also copied to the remote system if the server supports the option, and changes in size are reflected as well.

All echoing takes place at the remote site, so that (except for delays) the rlogin is transparent. Flow control via ^S and ^Q and flushing of input and output on interrupts are handled properly.

OPTIONS

-8

allows an eight-bit input data path at all times; otherwise parity bits are stripped except when the remote side's stop and start characters are other than ^S/^Q. Eight-bit mode is the default.

-L

allows the rlogin session to be run in litout mode.

-ec

sets the escape character to c. There is no space separating this option flag and the new escape character.

-c

require confirmation before disconnecting via ``~.''

-a

force the remote machine to ask for a password by sending a null local username. This option has no effect unless the standard UCB rlogin is executed in place of the Kerberos rlogin (see above).

-f

forward a copy of the local credentials to the remote system.

-F

forward a forwardable copy of the local credentials to the remote system.

-t termtype

replace the terminal type passed to the remote host with termtype.

-n

prevent suspension of rlogin via ``~^Z'' or ``~^Y''.

-7

force seven-bit transmissions.

-d

turn on socket debugging (via setsockopt(2)) on the TCP sockets used for communication with the remote host.

-k

request rlogin to obtain tickets for the remote host in realm realm instead of the remote host's realm as determined by krb_realmofhost(3).

-x

turn on DES encryption for data passed via the rlogin session. This applies only to input and output streams, so the username is sent unencrypted. This significantly reduces response time and significantly increases CPU utilization.

-PN

-PO

Explicitly request new or old version of the Kerberos ``rcmd'' protocol. The new protocol avoids many security problems found in the old one, but is not interoperable with older servers. (An "input/output error" and a closed connection is the most likely result of attempting this combination.) If neither option is specified, some simple heuristics are used to guess which to try.

-4

Use Kerberos V4 authentication only; don't try Kerberos V5.

SEE ALSO

rsh(1), kerberos(1), krb_sendauth(3), krb_realmofhost(3), rlogin(1) [UCB version], klogind(8)

FILES

~/.k5login

(on remote host) - file containing Kerberos principals that are allowed access.

BUGS

More of the environment should be propagated.