How to customize telnet login prompt on linux

Question

When I run login command on debian, I get:

hostname login: _

on RHEL5, Solaris or HP-UX I get:

login: _

I need to be able to customize login: and password: prompts it on a Linux box. I can recompile the package, but is there a better (easier) way to do it?

I was looking for some PAM config option but didn't find anything.

I know it can be done with the pam_set_item() function using PAM_USER_PROMPT constant, but is there a way to do such customization in a /etc/pam.d/* config file?

Thank you in advance.

UPDATE:

I need this to customize telnet username and password prompt. However, telnetd is using /bin/login for that prompt, this is why I asked for login customization in this question.

Solution 1

You may try to change system locale to your custom locale containing desired labels.

Solution 2

If you are using mingetty then you can specify the --nohostname parameter in /etc/inittab

1:2345:respawn:/sbin/mingetty --nohostname tty1
1:2345:respawn:/sbin/mingetty --nohostname tty2



--nohostname
          Do not print the hostname before the login prompt.

Solution 3

It have found that telnetd accepts -L /path/to/login option, so I have written few lines of python code to provide my own /bin/login alternative using PAM to authenticate and login -f to open a login shell.

In that python script I can define whatever prompt I need for both login: and password:.

Solution 4

if you use mgetty in /etc/inittab you can append the -p flag to change the login prompt

man mgetty


   -p <login prompt>
          Use the given string to prompt users for their login names. Various tokens are allowed in this string. These tokens are: @ for the system name, \n, \g, \f,  for  new-
          line, bell, and form feed, respectively.  \v and \r will expand to the OS version and release.  \P, \l and \L will expand to the tty name ("ttyS0").  \Y will give the
          Caller ID, \I the "CONNECT foobar" string returned by the modem, and \S or \b will output the port speed.  \N and \U give the number of users currently logged in.  \C
          will  be  changed  into  the result of ctime(), and \D or \d and \t or \T will output the date and time, respectively. Finally, \<digit> will use digit as octal/deci-
          mal/hexadecimal representation of the character to follow.

          The default prompt is specified at compile time.

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Comments

[samina]

I wasn't sure where to ask this question. I was considering also ServerFault, but I expected more PAM experts here.

[Bernie White]

Are you wanting to change for console or ssh connection?

[samina]

@BernieWhite: SSH is not an option (unfortunately). I need that for telnet server which (as far as I know) is using login binary.

[samina]

Sorry, I cannot use mgetty. It's needed for telnetd login prompt customization, and telnet calls /bin/login. It must work with /bin/login alone.

[samina]

I cannot use mingetty. See comment for Mike's answer.

[samina]

Thanks MikeyB. I need to change the prompt to something completely different. In other words, I need to be able to change prompt for example to: "Hello, what's your user name ?" and "your password please...".

[samina]

Yes, I just noted that "login:" and "password:" from login is locale aware. This might be best alternative for a recompiling the package.

[samina]

It tuns out that "login: " is taken from /usr/share/locale-langpack/en/LC_MESSAGES/shadow.mo, while "Password: " is taken from another /usr/share/locale-langpack/en/LC_MESSAGES/Linux-PAM.mo file.

[John Chew]

The -h option MikeyB mentions is used to control the display of /etc/issue.net before the line with the login: prompt, and has no effect on the display of the hostname on that line.