Proftpd

[root@hal ~]# uname -a
Linux hal.t0e.org 2.6.18-1.2849.fc6 #1 SMP Fri Nov 10 12:34:46 EST 2006 x86_64 x86_64 x86_64 GNU/Linux

[root@hal ~]# yum install proftpd
...

The original /etc/proftpd.conf file:

# This is the ProFTPD configuration file
# $Id: proftpd.conf,v 1.1 2004/02/26 17:54:30 thias Exp $

ServerName                      "ProFTPD server"
ServerIdent                     on "FTP Server ready."
ServerAdmin                     root@localhost
ServerType                      standalone
#ServerType                     inetd
DefaultServer                   on
AccessGrantMsg                  "User %u logged in."
#DisplayConnect                 /etc/ftpissue
#DisplayLogin                   /etc/ftpmotd
#DisplayGoAway                  /etc/ftpgoaway
DeferWelcome                    off

# Use this to excude users from the chroot
DefaultRoot                     ~ !adm

# Use pam to authenticate (default) and be authoritative
AuthPAMConfig                   proftpd
AuthOrder                       mod_auth_pam.c* mod_auth_unix.c

# Do not perform ident nor DNS lookups (hangs when the port is filtered)
IdentLookups                    off
UseReverseDNS                   off

# Port 21 is the standard FTP port.
Port                            21

# Umask 022 is a good standard umask to prevent new dirs and files
# from being group and world writable.
Umask                           022

# Default to show dot files in directory listings
ListOptions                     "-a"

# See Configuration.html for these (here are the default values)
#MultilineRFC2228               off
#RootLogin                      off
#LoginPasswordPrompt            on
#MaxLoginAttempts               3
#MaxClientsPerHost              none
#AllowForeignAddress            off     # For FXP

# Allow to resume not only the downloads but the uploads too
AllowRetrieveRestart            on
AllowStoreRestart               on

# To prevent DoS attacks, set the maximum number of child processes
# to 30.  If you need to allow more than 30 concurrent connections
# at once, simply increase this value.  Note that this ONLY works
# in standalone mode, in inetd mode you should use an inetd server
# that allows you to limit maximum number of processes per service
# (such as xinetd)
MaxInstances                    20

# Set the user and group that the server normally runs at.
User                            nobody
Group                           nobody

# Disable sendfile by default since it breaks displaying the download speeds in
# ftptop and ftpwho
UseSendfile                     no

# This is where we want to put the pid file
ScoreboardFile                  /var/run/proftpd.score

# Normally, we want users to do a few things.
<Global>
  AllowOverwrite                yes
  <Limit ALL SITE_CHMOD>
    AllowAll
  </Limit>
</Global>

# Define the log formats
LogFormat                       default "%h %l %u %t \"%r\" %s %b"
LogFormat                       auth    "%v [%P] %h %t \"%r\" %s"

# TLS
# Explained at http://www.castaglia.org/proftpd/modules/mod_tls.html
#TLSEngine                      on
#TLSRequired                    on
#TLSRSACertificateFile          /etc/pki/tls/certs/proftpd.pem
#TLSRSACertificateKeyFile       /etc/pki/tls/certs/proftpd.pem
#TLSCipherSuite                 ALL:!ADH:!DES
#TLSOptions                     NoCertRequest
#TLSVerifyClient                off
##TLSRenegotiate                ctrl 3600 data 512000 required off timeout 300
#TLSLog                         /var/log/proftpd/tls.log

# SQL authentication Dynamic Shared Object (DSO) loading
# See README.DSO and howto/DSO.html for more details.
#<IfModule mod_dso.c>
#   LoadModule mod_sql.c
#   LoadModule mod_sql_mysql.c
#   LoadModule mod_sql_postgres.c
#</IfModule>

# A basic anonymous configuration, with an upload directory.
#<Anonymous ~ftp>
#  User                         ftp
#  Group                                ftp
#  AccessGrantMsg               "Anonymous login ok, restrictions apply."
#
#  # We want clients to be able to login with "anonymous" as well as "ftp"
#  UserAlias                    anonymous ftp
#
#  # Limit the maximum number of anonymous logins
#  MaxClients                   10 "Sorry, max %m users -- try again later"
#
#  # Put the user into /pub right after login
#  #DefaultChdir                        /pub
#
#  # We want 'welcome.msg' displayed at login, '.message' displayed in
#  # each newly chdired directory and tell users to read README* files.
#  DisplayLogin                 /welcome.msg
#  DisplayFirstChdir            .message
#  DisplayReadme                        README*
#
#  # Some more cosmetic and not vital stuff
#  DirFakeUser                  on ftp
#  DirFakeGroup                 on ftp
#
#  # Limit WRITE everywhere in the anonymous chroot
#  <Limit WRITE SITE_CHMOD>
#    DenyAll
#  </Limit>
#
#  # An upload directory that allows storing files but not retrieving
#  # or creating directories.
#  <Directory uploads/*>
#    AllowOverwrite             no
#    <Limit READ>
#      DenyAll
#    </Limit>
#
#    <Limit STOR>
#      AllowAll
#    </Limit>
#  </Directory>
#
#  # Don't write anonymous accesses to the system wtmp file (good idea!)
#  WtmpLog                      off
#
#  # Logging for the anonymous transfers
#  ExtendedLog          /var/log/proftpd/access.log WRITE,READ default
#  ExtendedLog          /var/log/proftpd/auth.log AUTH auth
#
#</Anonymous>

My modified /etc/proftpd.conf file:

ServerName                      "-=hello=-"
ServerIdent                     on "Hello World"
ServerType                      standalone
DefaultServer                   on

# Port 21 is the standard FTP port.
Port                            21

# Umask 022 is a good standard umask to prevent new dirs and files
# from being group and world writable.
Umask                           022

# To prevent DoS attacks, set the maximum number of child processes
# to 30.  If you need to allow more than 30 concurrent connections
# at once, simply increase this value.  Note that this ONLY works
# in standalone mode, in inetd mode you should use an inetd server
# that allows you to limit maximum number of processes per service
# (such as xinetd).
MaxInstances                    30

# Set the user and group under which the server will run.
User                            nobody
Group                           nobody

# To cause every FTP user to be "jailed" (chrooted) into their home
# directory, uncomment this line.
DefaultRoot ~

# Don't do ident lookups:
# http://freebsd.munk.me.uk/archives/73-ProFTPD-Delay-Whilst-Authenticating.html
# When connecting to the proftpd server, a noticeable delay of
# around 5 seconds can be seen. To fix this I switched off ident
# lookups in proftpd.conf and all was fine:
IdentLookups off

# Use only AuthUserFiles when authenticating, and not the system's /etc/passwd
# for /etc/passwd mod_auth_unix.c
AuthOrder mod_auth_file.c

#AuthUserFile -- Specify alternate passwd file
AuthUserFile /etc/proftpd/passwd

#AuthGroupFile -- Specify alternate group file
AuthGroupFile /etc/proftpd/group

# make listed files appear to be owned by the logged-in user
DirFakeUser on ~

# Normally, we want files to be overwriteable.
AllowOverwrite on

# Delay engine reduces impact of the so-called Timing Attack described in
# http://security.lss.hr/index.php?page=details&ID=LSS-2004-10-02
# It is on by default.
<IfModule mod_delay.c>
 DelayEngine off
</IfModule>

# Bar use of SITE CHMOD by default
<Limit SITE_CHMOD>
  DenyAll
</Limit>

<Anonymous /var/duck>
  AnonRequirePassword on
  RequireValidShell off
  User duck
  Group duck
</Anonymous>

[root@hal proftpd]# cat group
duck:x:501:
[root@hal proftpd]# cat passwd
duck:$1$6MYsRLDl$NACe/Kd5k5LPM3qQs8niO.:501:501::/var/duck:/bin/false

ftpasswd download from: http://www.castaglia.org/proftpd/contrib/ftpasswd
ftpasswd info: http://www.castaglia.org/proftpd/
ftpasswd usage: http://www.castaglia.org/proftpd/contrib/ftpasswd.html
add user to password file...

# echo "password" | ftpasswd --passwd --file=/etc/proftpd/passwd --name=duck --uid=501 --gid=501 --home=/var/duck --shell=/bin/false --stdin