chore(readme): Even more precise description

This commit is contained in:
Pratik Tripathy
2025-10-11 19:34:57 +05:30
parent d92b0284a5
commit a5b0838fb3

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@@ -1,16 +1,16 @@
# Linux Server Hardener
POSIX-compliant shell script that automates server security hardening on a new Linux/FreeBSD server.
The script is intended to be executed immediately after you have access to a new Linux/FreeBSD server (most likely a VPS) as **root**.
It is intended to be executed **interactively** as `root`.
## Usage
- WARNING: Make sure you:
- Have root privilege to the server
- Have root access to the server
- Have 2 ssh sessions active to the server:
- 1st for running the script
- 2nd for viewing script's logs and to recover from it's failure
- SAVE ALL CREDENTIALS SHOWN POST EXECUTION: THEY AREN'T SAVED ANYWHERE AND WON'T BE DISPLAYED AGAIN
- 1st: for running the script
- 2nd: for viewing script's logs and to recover from it's failure
- SAVE ALL CREDENTIALS SHOWN POST EXECUTION: THEY AREN'T SAVED ANYWHERE AND WON'T BE DISPLAYED AGAIN.
- Options:
- `-r`: Reset root password
@@ -22,7 +22,7 @@ curl -L -o harden.sh https://sot.li/hardensh
cat harden.sh # review content
chmod +x harden.sh
# Harden server (SSH, Fail2ban, Firewalld/pf)
# Harden server: SSH hardening, Fail2ban, Firewalld/pf
./harden.sh
# Create new privileged (sudo) user & harden server
@@ -32,13 +32,13 @@ chmod +x harden.sh
./harden.sh -r -u jay
```
- Quick & dirty execute:
- Quick & Dirty:
```sh
curl -sL https://sot.li/hardensh | sh -s -- -r -u jay
```
> There are risks involved with running scripts directly from web, as done above. Everyone does it anyways; you have been warned.
> There are security risks involved with running scripts directly from web, as done above. Everyone does it; but, you have been warned.
## Post Installation
@@ -48,16 +48,16 @@ chmod +x harden.sh
# Firewalld: Check firewall status
sudo firewall-cmd --status && sudo firewall-cmd --list-services
# Firewalld: Allow a port/service (dhcp)
sudo firewall-cmd --add-service=dhcp --permanent
# Firewalld: Allow a port/service (e.g., dhcp)
sudo firewall-cmd --permanent --add-service=dhcp
# Firewalld: Block a port/service (http)
sudo firewall-cmd --remove-service=http --permanent
# Firewalld: Block a port/service (e.g., http)
sudo firewall-cmd --permanent --remove-service=http
# Fail2ban: List all active jails
sudo fail2ban-client status
# Fail2ban: List all IP banned by a jail (sshd)
# Fail2ban: List all IP banned by a jail (e.g., sshd)
sudo fail2ban-client status sshd
# Fail2ban: Manually ban an IP
@@ -70,19 +70,19 @@ chmod +x harden.sh
- FreeBSD:
```sh
# pf: active rules
# pf: Show active rules
sudo pfctl -s rules
# pf: Allow or block services
# Edit /etc/pf.conf & add the port/service to the comma separated list in { }
# Edit /etc/pf.conf & add/remove the port/service to the comma separated list in { }
#
# OR use the following command (allows dhcp)
# OR use the following command (e.g., allow dhcp)
sed -i.bak 's/[[:space:]]}/, dhcp }/' /etc/pf.conf && pfctl -nf /etc/pf.conf && pfctl -vvf /etc/pf.conf
# Fail2ban: List all active jails
sudo fail2ban-client status
# Fail2ban: List all IP banned by a jail (sshd)
# Fail2ban: List all IP banned by a jail (e.g., sshd)
sudo fail2ban-client status sshd
# Fail2ban: Manually ban an IP
@@ -103,49 +103,57 @@ Tested and working on:
- FreeBSD:
- FreeBSD 14.3
> Tested with each OS's official qcow2 file through KVM virtualisation.
## What does it do exactly?
Depending on options chosen & OS (Linux vs FreeBSD) it does the following:
Depending on options chosen & OS (Linux vs FreeBSD), it does the following:
1. Reset `root` users password (optional)
2. Create new user & give it `sudo` privileges (optional)
3. Generate OpenSSH (ed25519) keys (public & private) for the user with a passphrase
1. (Optional) Resets `root` users password
2. (Optional) Creates new user & give it `sudo` privileges
3. Generates OpenSSH (ed25519) keys (public & private) for the user with a passphrase
4. Updates SSH configuration to:
a. Disable `root` login
b. Disable password login
c. Enable key-only login
- Disable `root` login
- Disable password login
- Enable sshkey-only login
5. Installs applications:
a. Linux: curl, sudo, firewalld, fail2ban
b. FreeBSD: curl, sudo, fail2ban
- Linux: curl, sudo, firewalld, fail2ban
- FreeBSD: curl, sudo, fail2ban
6. Configures firewall which allows incoming sshd, http, https traffic & blocks everything else:
a. Linux: `firewalld` is used as firewall
b. FreeBSD: `pf` is used as firewall
7. Configures `fail2ban` to with following jails (FreeBSD: `pf` table is used to block IPs):
a. sshd
b. nginx-botsearch
c. nginx-http-auth
d. nginx-limit-req
e. haproxy-http-auth
f. recidive
- Linux: `firewalld` is used as firewall
- FreeBSD: `pf` is used as firewall
7. Linux: Configures `fail2ban` to with following jails (FreeBSD: `pf` table is used to block IPs):
- sshd
- nginx-botsearch
- nginx-http-auth
- nginx-limit-req
- haproxy-http-auth
- recidive
8. Displays following on console:
a. New root password
b. New user name & password
c. SSH Private & Public keys
d. SSH Passphrase
- New root password
- New user name & password
- SSH Private & Public keys
- SSH Passphrase
9. Deletes SSH Private Key from server
> [!NOTE] Handling Operation Failure
>
> - The script creates back up of each file it changes, in the same location as the original file. Backup file name: [original-name].bak.[timestamp]
> - On failure of an operation that depends on a configuration file, the script restores the original file and restarts the relevant service.
> - Reason for failures can be found in the log file.
### Why `firewalld` and not `ufw`?
- `firewalld` is default firewall on Rocky Linux, SUSE, Fedora, RHEL
- Can use similar commands like `ufw` for basic administration
- Can use similar commands like `ufw`, for basic administration
- Comes with a lot more power when needed
## To-do
- [ ] LUKS encryption
- [ ] Unattended-updates if distro supports it (do it during installations)
- [ ] Layer 2 security: Midtier: OSSEC: Mid tier attack prevention
- [ ] Audit: Lynis: System security audits
- [ ] Layer 2 security: Midtier: OSSEC
- [ ] Audit: Lynis
- [ ] Monitoring + Alerts: Goaccess???
- [ ] Backups: ???