FTP#

📒 FTP (File Transfer Protocol)#

Used to upload/download files between client and server.
Works on TCP ports 21 (control) and 20 (data).
Needs login credentials (unless it’s anonymous FTP).
FTP sends data in clear-text (not secure by default).
Two modes:
- Active Mode: Server connects back to client (can be blocked by firewalls).
- Passive Mode: Client connects to server (firewall-friendly).
Can use FTP programs or browser support.
Commands include file upload, download, delete, and directory operations.
Server responds with status codes (e.g., 200 = success).

sudo apt install vsftpd

Used to configure FTP settings like login access, anonymous access, logging, etc.
Some settings are enabled by default, others are commented out.
Additional options can be found in the man page:

man vsftpd.conf

Setting	Description
`listen=NO`	Run with inetd or standalone
`listen_ipv6=YES`	Use IPv6
`anonymous_enable=NO`	Disable anonymous FTP
`local_enable=YES`	Allow local Linux users to log in
`dirmessage_enable=YES`	Show directory messages
`use_localtime=YES`	Use system’s local time
`xferlog_enable=YES`	Enable upload/download logs
`connect_from_port_20=YES`	Use port 20 for data connection
`secure_chroot_dir=/var/run/vsftpd/empty`	Required secure empty dir
`pam_service_name=vsftpd`	PAM auth service name
`rsa_cert_file=/etc/ssl/certs/ssl-cert-snakeoil.pem`	SSL cert file
`rsa_private_key_file=/etc/ssl/private/ssl-cert-snakeoil.key`	SSL key file
`ssl_enable=NO`	SSL disabled by default

Used to block specific users from using FTP service.
Even if users exist on the system, they can’t log in via FTP if listed here.

Anonymous login can be useful in internal networks but is dangerous if enabled without proper restrictions.

Setting	Description
`anonymous_enable=YES`	Allow anonymous login
`anon_upload_enable=YES`	Allow anonymous users to upload files
`anon_mkdir_write_enable=YES`	Allow anonymous users to create folders
`no_anon_password=YES`	Don’t ask for a password
`anon_root=/home/username/ftp`	Anonymous users will land here
`write_enable=YES`	Allow commands like upload/delete/rename

ftp 10.129.14.136

ftp> ls

ftp> status

Setting	Description
`dirmessage_enable=YES`	Show directory welcome message
`chown_uploads=YES`	Change ownership of anonymous uploads
`chown_username=username`	Set ownership to this user
`local_enable=YES`	Allow local users to login
`chroot_local_user=YES`	Lock local users to their home dir
`chroot_list_enable=YES`	Apply chroot jail only to listed users
`hide_ids=YES`	Hide user/group IDs in listings
`ls_recurse_enable=YES`	Enable recursive listing (`ls -R`)