pure-authd (8) Linux Manual Page

pure-authd – External authentication agent for Pure-FTPd.

Syntax

pure-authd [-p </path/to/pidfile>] [-u uid] [-g gid] [-B] <-s /path/to/socket> -r /program/to/run

Description

pure-authd is a daemon that forks an authentication program, waits for an authentication reply, and feed them to an application server.

pure-authd listens to a local Unix socket. A new connection to that socket should feed pure-authd the following structure :

account:xxx

password:xxx

localhost:xxx

localport:xxx

peer:xxx

end

(replace xxx with appropriate values) . localhost, localport and peer are numeric IP addresses and ports. peer is the IP address of the remote client.

These arguments are passed to the authentication program, as environment variables :

AUTHD_ACCOUNT

AUTHD_PASSWORD

AUTHD_LOCAL_IP

AUTHD_LOCAL_PORT

AUTHD_REMOTE_IP

AUTHD_ENCRYPTED

The authentication program should take appropriate actions to fetch account info according to these arguments, and reply to the standard output a structure like the following one :

auth_ok:1

uid:42

gid:21

dir:/home/j

end

auth_ok:xxx

If xxx is 0, the user was not found (the next authentication method passed to pure-ftpd will be tried) . If xxx is -1, the user was found, but there was a fatal authentication error : user is root, password is wrong, account has expired, etc (next authentication methods will not be tried) . If xxx is 1, the user was found and successfully authenticated.

uid:xxx

The system uid to be assigned to that user. Must be > 0.

gid:xxx

The primary system gid. Must be > 0.

dir:xxx

The absolute path to the home directory. Can contain /./ for a chroot jail.

slow_tilde_expansion:xxx (optional, default is 1)

When the command ‘cd ~user’ is issued, it’s handy to go to that user’s home directory, as expected in a shell environment. But fetching account info can be an expensive operation for non-system accounts. If xxx is 0, ‘cd ~user’ will expand to the system user home directory. If xxx is 1, ‘cd ~user’ won’t expand. You should use 1 in most cases with external authentication, when your FTP users don’t match system users. You can also set xxx to 1 if you’re using slow nss_* system authentication modules.

throttling_bandwidth_ul:xxx (optional)

The allocated bandwidth for uploads, in bytes per second.

throttling_bandwidth_dl:xxx (optional)

The allocated bandwidth for downloads, in bytes per second.

user_quota_size:xxx (optional)

The maximal total size for this account, in bytes.

user_quota_files:xxx (optional)

The maximal number of files for this account.

ratio_upload:xxx (optional)

radio_download:xxx (optional)

The user must match a ratio_upload:ratio_download ratio.

Only one authentication program is forked at a time. It must return quickly.

Options

-u <uid>

Have the daemon run with that uid.

-g <gid>

Have the daemon run with that gid.

-B

Fork in background (daemonization).

-s </path/to/socket>

Set the full path to the local Unix socket.

-R </path/to/program>

Set the full path to the authentication program.

-h

Output help information and exit.

Examples

To run this program the standard way type:

pure-authd -s /var/run/ftpd.sock -r /usr/bin/my-auth-program &

pure-ftpd -lextauth:/var/run/ftpd.sock &

/usr/bin/my-auth-program can be as simple as :

#! /bin/sh

echo ‘auth_ok:1’

echo ‘uid:42’

echo ‘gid:21’

echo ‘dir:/home/j’

echo ‘end’

Authors

Frank DENIS <j at pureftpd dot org>

See Also

ftp(1), pure-ftpd(8) pure-ftpwho(8) pure-mrtginfo(8) pure-uploadscript(8) pure-statsdecode(8) pure-pw(8) pure-quotacheck(8) pure-authd(8) RFC 959, RFC 2389, RFC 2228 and RFC 2428.