why ftp behaves diff than normal login on auth failures

[skt_skt]

HP-UX 11.11

I want to know why multple ftp auth failure attempts on accounts( with shells /usr/bin/ksh & /usr/bin/false etc) do not return "account diabled" message while the normal terminal/putty logins attempts with the same accounts return error (ofcourse ftp account with /usr/bin/false will not not attempt login).

Any one know the logic behind it? Why FTP need to behave this way?

[/root] what /usr/bin/ftp
/usr/bin/ftp:
$Revision: @(#) ftp R11.11_BL2006_0224_2 PATCH_11.11 PHNE_34544
Copyright (c) 1985, 1989 Regents of the University of California.
Revision 1.1.214.5 Fri Feb 24 15:03:01 GMT 2006

[Steven Schweda]

> Why FTP need to behave this way?

That's the way it was written? It doesn't
_need_ to behave that way. If you can write
your own FTP server program, then you can
probably make it do anything you want.

Perhaps interactive log-ins go through the
"login" program, and FTP sessions do not.
"login" does things which your FTP server
does not. "man login".

[Bill Hassell · Accepted solution]

ftp does *NOT* login. The concept of a login is associated with an interactive shell and part of the task is to setup an environment for subprocesses. ftp simply borrows the authentication mechanism (PAM) but does not use the login program and does not count login attempts. That's why scp or sftp are preferred with their multiple authentication choices (ie, password, public key, etc).