Ftp server #linux #services

 To enable and use an FTP server on Kali Linux, you can use `vsftpd` (Very Secure FTP Daemon). Here’s a step-by-step guide:

### 1. Install vsftpd

First, install `vsftpd` using the following command:

```bash

sudo apt update

sudo apt install vsftpd

```

### 2. Configure vsftpd

After installation, you need to configure the FTP server. The configuration file is located at `/etc/vsftpd.conf`.

Open the configuration file with a text editor:

```bash

sudo nano /etc/vsftpd.conf

```

### 3. Basic Configuration

Make the following changes to the configuration file for a basic setup:

- Uncomment the following lines:

  ```plaintext

  write_enable=YES

  local_umask=022

  ```

  

- Add or modify the following lines to ensure proper functionality:

  ```plaintext

  anonymous_enable=NO

  local_enable=YES

  chroot_local_user=YES

  ```

### 4. Create FTP Directory and Set Permissions

Create a directory for the FTP users and set the appropriate permissions. For example, you can create a directory called `ftp` under `/home`:

```bash

sudo mkdir /home/ftp

sudo chmod 755 /home/ftp

```

### 5. Create an FTP User

Create a user for FTP access. Replace `ftpuser` with the desired username:

```bash

sudo adduser ftpuser

```

Follow the prompts to set the password and user details.

### 6. Start vsftpd Service

Start the `vsftpd` service and enable it to start on boot:

```bash

sudo systemctl start vsftpd

sudo systemctl enable vsftpd

```

### 7. Adjust Firewall Settings

If you have a firewall enabled, allow FTP traffic:

```bash

sudo ufw allow 20/tcp

sudo ufw allow 21/tcp

```

### 8. Test the FTP Server

You can test the FTP server using an FTP client or the command line. To connect via command line, use:

```bash

ftp localhost

```

Then, enter the username (`ftpuser`) and password when prompted.

### 9. Additional Configuration (Optional)

For a more secure setup, consider the following additional configurations:

- **Disable anonymous access**: Ensure `anonymous_enable=NO` is set.

- **Use FTP over SSL/TLS**:

  - Generate SSL certificates:

    ```bash

    sudo openssl req -x509 -nodes -days 365 -newkey rsa:2048 -keyout /etc/ssl/private/vsftpd.key -out /etc/ssl/certs/vsftpd.crt

    ```

  - Configure vsftpd to use SSL:

    ```plaintext

    ssl_enable=YES

    rsa_cert_file=/etc/ssl/certs/vsftpd.crt

    rsa_private_key_file=/etc/ssl/private/vsftpd.key

    ```

- **Restrict users to their home directories**:

  - Ensure `chroot_local_user=YES` is set.

  - Add users to the `chroot_list` by creating and editing the file `/etc/vsftpd.chroot_list`:

    ```bash

    sudo nano /etc/vsftpd.chroot_list

    ```

  - Add usernames to the file, one per line.

### Restart vsftpd Service

After making any changes to the configuration, restart the `vsftpd` service to apply them:

```bash

sudo systemctl restart vsftpd

```

Your FTP server should now be set up and ready to use on Kali Linux. If you need further customization or face any issues, refer to the `vsftpd` documentation or ask for more specific help.

The error "500 OOPS: vsftpd: refusing to run with writable root inside chroot()" occurs because `vsftpd` is refusing to run with a writable root inside a chroot jail, which is a security measure. To fix this, you need to adjust the permissions of the home directory or configure `vsftpd` to allow this setup.

Here's a step-by-step guide to resolve this issue:

### 1. Adjust Directory Permissions

You need to make the home directory non-writable by the user. Here’s how you can do it:

```bash

sudo chmod a-w /home/maverick

```

Then create a subdirectory within the user's home directory that the user can write to:

```bash

sudo mkdir /home/maverick/ftp

sudo chown maverick:maverick /home/maverick/ftp

sudo chmod 755 /home/maverick/ftp

```

### 2. Allow Writable Root Inside Chroot

Alternatively, you can allow writable root directories inside the chroot by enabling `allow_writeable_chroot` in the `vsftpd` configuration. This is less secure but can be used if adjusting directory permissions is not suitable for your use case.

Open the `vsftpd` configuration file:

```bash

sudo nano /etc/vsftpd.conf

```

Add or modify the following line:

```plaintext

allow_writeable_chroot=YES

```

### 3. Restart vsftpd Service

After making changes to the configuration, restart the `vsftpd` service to apply them:

```bash

sudo systemctl restart vsftpd

```

### 4. Test FTP Login

Now, try logging in again:

```bash

ftp localhost

```

Enter your username and password when prompted.

### Additional Tips

- **Check for Configuration Issues**: Ensure there are no conflicting settings in the `vsftpd.conf` file.

- **Verbose Logging**: Enable verbose logging in `vsftpd` to get more detailed information in case of issues:

  ```plaintext

  log_ftp_protocol=YES

  ```

- **File Permissions**: Make sure the FTP user's home directory and its subdirectories have appropriate permissions and ownership.

### Example vsftpd.conf Configuration

Here’s an example configuration for reference:

```plaintext

listen=YES

anonymous_enable=NO

local_enable=YES

write_enable=YES

local_umask=022

dirmessage_enable=YES

use_localtime=YES

xferlog_enable=YES

connect_from_port_20=YES

chroot_local_user=YES

allow_writeable_chroot=YES

secure_chroot_dir=/var/run/vsftpd/empty

pam_service_name=vsftpd

rsa_cert_file=/etc/ssl/certs/ssl-cert-snakeoil.pem

rsa_private_key_file=/etc/ssl/private/ssl-cert-snakeoil.key

ssl_enable=NO

```

By following these steps, you should be able to resolve the "500 OOPS" error and successfully log in to the FTP server on Kali Linux.