login.krb5 - kerberos enhanced login program

login.krb5 [-p] [-fFe username] [-r | -k | -K | -h hostname]

login.krb5 is a modification of the BSD login program which is used for two functions. It is the sub-process used by krlogind and telnetd to initiate a user session and it is a replacement for the command-line login program which, when invoked with a password, acquires Kerberos tickets for the user.

login.krb5 will prompt for a username, or take one on the command line, as login.krb5 username and will then prompt for a password. This password will be used to acquire Kerberos Version 5 tickets and Kerberos Version 4 tickets (if possible.) It will also attempt to run aklog to get AFS tokens for the user. The version 5 tickets will be tested against a local krb5.keytab if it is available, in order to verify the tickets, before letting the user in. However, if the password matches the entry in /etc/passwd the user will be unconditionally allowed (permitting use of the machine in case of network failure.)

-p

preserve the current environment

-r hostname

pass hostname to rlogind. Must be the last argument.

-h hostname

pass hostname to telnetd, etc. Must be the last argument.

-k hostname

Use Kerberos V4 to login. Must be the last argument.

-K hostname

Use Kerberos V4 to login. Must be the last argument.

-f name

Perform pre-authenticated login, e.g., datakit, xterm, etc.; allows preauthenticated login as root.

-F name

Perform pre-authenticated login, e.g., datakit, xterm, etc.; allows preauthenticated login as root.

-e name

Perform pre-authenticated, encrypted login. Must do term negotiation.

login.krb5 is also configured via krb5.conf using the login stanza. A collection of options dealing with initial authentication are provided:

krb5_get_tickets

Use password to get V5 tickets. Default value true.

krb4_get_tickets

Use password to get V4 tickets. Default value false.

krb4_convert

Use Kerberos conversion daemon to get V4 tickets. Default value false. If false, and krb4_get_tickets is true, then login will get the V5 tickets directly using the Kerberos V4 protocol directly. This does not currently work with non MIT-V4 salt types (such as the AFS3 salt type.) Note that if configuration parameter is true, and the krb524d is not running, login will hang for approximately a minute under Solaris, due to a Solaris socket emulation bug.

krb_run_aklog

Attempt to run aklog. Default value false.

aklog_path

Where to find it [not yet implemented.] Default value $(prefix)/bin/aklog.

accept_passwd

Don't accept plaintext passwords [not yet implemented]. Default value false.

All diagnostic messages are returned on the connection or tty associated with stderr.

rlogind(8), rlogin(1), telnetd(8)

Should use a config file to select use of V5, V4, and AFS, as well as policy for startup.