Re: Passwords on Linux systems(for all flavors)
Dwayne Ghant <[email protected]>
| Newsgroups | gmane.comp.security.linux |
|---|---|
| Message-ID | <[email protected]> |
What about unicode charectors in passwords. Glynn Clements wrote: >[email protected] wrote: > > > >>I would like to know the place where I can find the linux password >>constraints for the various linux flavors. What I mean is the details >>like number of key spaces or the key length, the types of charactors >>that can be used, the restrictions and the number of times the >>password can be tried if not infinite, etc. I am in need of these >>details very urgently, so please do help me on this topic. >> >> > >On any system which uses PAM (which is almost every modern Linux >system), most of these are configuration options, controlled through >the files in /etc/pam.d and /etc/security. > >For the underlying libc crypt() function, assuming MD5 passwords, the >password can be any NUL-terminated string. There is no minimum or >maximum length, nor any restriction on which characters (bytes) the >password can contain. > >However, if a password contains any control characters or non-ASCII >(8-bit) characters, there may be problems entering it in certain >contexts. Also, individual programs may read the password into a >fixed-size buffer, which will impose an upper limit on the length of a >password. > > > -- Dwayne A. Ghant Application Developer Temple University 215.204.5555 [email protected]