UPPER letters in login names - Slackware

This is a discussion on UPPER letters in login names - Slackware ; Hallo alle miteinander, "useradd" from "shadow-4.0.3" doesn't allow UPPER letters in login names, p.e. "Helmut". When I take the program "useradd" from a Debian or SuSE distribution disk: no such problem. The direkt source of trouble is ...libmisc/chkname.c I need ...

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Thread: UPPER letters in login names

  1. UPPER letters in login names

    Hallo alle miteinander,

    "useradd" from "shadow-4.0.3" doesn't allow UPPER letters in login
    names, p.e. "Helmut".

    When I take the program "useradd" from a Debian or SuSE distribution
    disk: no such problem.

    The direkt source of trouble is

    ...libmisc/chkname.c

    I need UPPER letters p.e. for machine accounts (Samba etc.).

    Is there any technical or RFC reason for this behaviour?

    Viele Gruesse
    Helmut

    "Ubuntu" - an African word, meaning "Slackware is too hard for me".


  2. Re: UPPER letters in login names

    On August 7, 2008 11:21, in alt.os.linux.slackware, Helmut Hullen
    (helmut@hullen.de) wrote:

    > Hallo alle miteinander,
    >
    > "useradd" from "shadow-4.0.3" doesn't allow UPPER letters in login
    > names, p.e. "Helmut".

    [snip]
    > I need UPPER letters p.e. for machine accounts (Samba etc.).


    For those, you can manually edit the password file using vipw(1).

    > Is there any technical or RFC reason for this behaviour?


    Yes, there is a technical reason. One reason is that in Unix (and thus
    Slackware Linux), userids are recorded in lower case, so that getty(1) can
    determine if an upper-case-only teletype device is being used to log on. If
    getty(1) detects uppercase in the username, it switches the line
    conditioning mode so that all output lowercase is converted to upper case,
    and all input uppercase is converted to lowercase.

    --
    Lew Pitcher

    Master Codewright & JOAT-in-training | Registered Linux User #112576
    http://pitcher.digitalfreehold.ca/ | GPG public key available by request
    ---------- Slackware - Because I know what I'm doing. ------



  3. Re: UPPER letters in login names

    Lew Pitcher wrote:
    > If getty(1) detects uppercase in the username, it switches the line
    > conditioning mode so that all output lowercase is converted to upper case,
    > and all input uppercase is converted to lowercase.


    I _think_, but cannot test this, that this behaviour is invoked
    (with a normal getty, the agetty Slackware is using doesn't do
    this) when the FIRST letter of the typed-in login name is a capital.
    Getty then assumes that the user can NOT type in lower case chars,
    so will convert everything the user types to lower case (but ECHO
    it in upper case).
    Note, if you manage to logon this behaviour will be for the whole
    session, not just the login/password (the iuclc parameter to stty
    see 'man stty', will be set by getty).

    Of course graphical login managers (like kdm) don't have this
    problem, as they're used only by the local keyboard, not a
    "remote terminal for which attributes are unknown".
    --
    ************************************************** *****************
    ** Eef Hartman, Delft University of Technology, dept. SSC/ICT **
    ** e-mail: E.J.M.Hartman@tudelft.nl, fax: +31-15-278 7295 **
    ** snail-mail: P.O. Box 5031, 2600 GA Delft, The Netherlands **
    ************************************************** *****************

  4. Re: UPPER letters in login names

    Eef Hartman wrote:
    > Lew Pitcher wrote:
    >> If getty(1) detects uppercase in the username, it switches the line
    >> conditioning mode so that all output lowercase is converted to upper case,
    >> and all input uppercase is converted to lowercase.

    >
    > I _think_, but cannot test this, that this behaviour is invoked
    > (with a normal getty, the agetty Slackware is using doesn't do
    > this) when the FIRST letter of the typed-in login name is a capital.
    > Getty then assumes that the user can NOT type in lower case chars,
    > so will convert everything the user types to lower case (but ECHO
    > it in upper case).
    > Note, if you manage to logon this behaviour will be for the whole
    > session, not just the login/password (the iuclc parameter to stty
    > see 'man stty', will be set by getty).


    The agetty Slackware is using *does* do this, as the test below shows.

    Welcome to Linux 2.6.24.5-smp (tty5)

    lankhmar login: KEES
    PASSWORD:
    LOGIN INCORRECT

    LANKHMAR LOGIN:


    This is on a Slackware 12.1 VC. I'm quite sure i've seen this recently
    on a Slackware 10.2 too.


    An other problem with upper case chars in user names is mail delivery.
    Most -if not all- email software will handle the "local part" of an
    email address (i.e. the string before the @ sign) in a case insensitive
    way when delivering to local mailboxes.
    At least sendmail will convert SomeUser@your.domain or
    SOMEUSER@your.domain to someuser@your.domain before it selects the
    mailbox, or alias, to deliver to.

    If you only want to use upper or mixed case names for computer
    accounts in samba, then email delivery is probably not a concern
    though.


    Regards,

    Kees.

    --
    Kees Theunissen.

  5. Re: UPPER letters in login names

    On Thu, 7 Aug 2008, Lew Pitcher wrote:

    >
    > On August 7, 2008 11:21, in alt.os.linux.slackware, Helmut Hullen
    > (helmut@hullen.de) wrote:
    >
    >> Hallo alle miteinander,
    >>
    >> "useradd" from "shadow-4.0.3" doesn't allow UPPER letters in login
    >> names, p.e. "Helmut".

    > [snip]
    >> I need UPPER letters p.e. for machine accounts (Samba etc.).

    >
    > For those, you can manually edit the password file using vipw(1).
    >
    >> Is there any technical or RFC reason for this behaviour?

    >
    > Yes, there is a technical reason. One reason is that in Unix (and thus
    > Slackware Linux), userids are recorded in lower case, so that getty(1) can
    > determine if an upper-case-only teletype device is being used to log on. If
    > getty(1) detects uppercase in the username, it switches the line
    > conditioning mode so that all output lowercase is converted to upper case,
    > and all input uppercase is converted to lowercase.
    >


    Also because many/most/all MTA's don't distinguish between upper and
    lowercase, so, by allowing two separate system users -
    'helmut' and 'Helmet', the MTA will be confused and each may get the
    others mail, IIRC MTA's are not teh only thing that can get confused
    either.


    --
    Cheers
    Res
    --- Usenet policy, and why I might ignore you ---
    1/ GoogleGroups are UDP'd on my nntp server. If you use them, don't
    waste your time or energy replying to me.

    2/ If only cleanfeed filtered out trolls as well as spam, usenet would be
    a nicer place.

  6. Re: UPPER letters in login names

    On 2008-08-07, Eef Hartman wrote:
    >
    > Of course graphical login managers (like kdm) don't have this
    > problem, as they're used only by the local keyboard, not a
    > "remote terminal for which attributes are unknown".


    I am pretty sure kdm can be configured to listen on the network for
    XDMCP connections. Then again, if a machine can do XDMCP, it should be
    able to send both upper and lower-case characters.

    --keith


    --
    kkeller-usenet@wombat.san-francisco.ca.us
    (try just my userid to email me)
    AOLSFAQ=http://www.therockgarden.ca/aolsfaq.txt
    see X- headers for PGP signature information


  7. Re: UPPER letters in login names

    Hallo, Keith,

    Du meintest am 07.08.08:

    >> Of course graphical login managers (like kdm) don't have this
    >> problem, as they're used only by the local keyboard, not a
    >> "remote terminal for which attributes are unknown".


    > I am pretty sure kdm can be configured to listen on the network for
    > XDMCP connections. Then again, if a machine can do XDMCP, it should
    > be able to send both upper and lower-case characters.


    Thank you all - now I'm confused on a higher level.

    When working with samba I'm trained to write then Logon names for
    machine accounts with UPPER letters, many examples also propose that.

    And some other distributions have a "useradd" which allows that.

    I will ask in the Samba mailinglist wether it is necessary.

    Viele Gruesse
    Helmut

    "Ubuntu" - an African word, meaning "Slackware is too hard for me".


  8. Re: UPPER letters in login names

    On Fri, 8 Aug 2008, Helmut Hullen wrote:
    >> be able to send both upper and lower-case characters.


    >
    > Thank you all - now I'm confused on a higher level.
    >




    --
    William Hunt, Portland Oregon USA

  9. Re: UPPER letters in login names

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    Hash: SHA1

    On 2008-08-07, Helmut Hullen wrote:
    > I need UPPER letters p.e. for machine accounts (Samba etc.).


    No you don't, at least not with samba. As far as Windows is concerned,
    there is no difference between 'a' and 'A'. Just enter all your
    machine names in with lowercase letters and everything will be fine.

    - --
    It is better to hear the rebuke of the wise,
    Than for a man to hear the song of fools.
    Ecclesiastes 7:5
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