Re: complex characters in UID attribute

[Michael Ströder <michael@stroeder.com>]

Keutel, Jochen (mlists) wrote:
>   Hello,
>   the ":" is a special character for Unix. (E.g. it's the column
> delimiter in /etc/passwd and friends.) So Unix forbids
> the usage of ":" in user names.
> 
> POSIX defines
> (http://pubs.opengroup.org/onlinepubs/009695399/basedefs/xbd_chap03.html#tag_03_426):
> 
> ---
> To be portable across systems conforming to IEEE Std 1003.1-2001, the
> value is composed of characters from the portable filename character set.
> ---
> 
> This portable character set is defined as
> (http://pubs.opengroup.org/onlinepubs/009695399/basedefs/xbd_chap03.html#tag_03_276):
> 
> ---
> 
> The set of characters from which portable filenames are constructed.
> 
>     A B C D E F G H I J K L M N O P Q R S T U V W X Y Z
>     a b c d e f g h i j k l m n o p q r s t u v w x y z
>     0 1 2 3 4 5 6 7 8 9 . _ -
> 
> The last three characters are the period, underscore, and hyphen
> characters, respectively.
> 
> ---
> 
> So LDAP allows ":" in uid (because it has DirectoryString syntax) but
> the application (Unix/POSIX) forbids it.

Additionally if using SSH logins one should stick to lower-case chars.

Ciao, Michael.