Package:Sshguard

app-admin/sshguard


Source Repository:Gentoo Portage Tree

Summary: protects hosts from brute force attacks against ssh

Use Flags

ipfilter
Enable ipfilter firewall support (only for *bsd)

Sshguard

sshguard is an intrusion prevention system. sshguard parses server logs, determines malicious activity, and then bans malicious users via firewall rules. sshguard is written in C so it does not tax an interprator.

Installation

Emerge

To install sshguard:

# emerge app-admin/sshguard

Configuration

sshguard does not have a configuration file. sshguard is controlled by flags passed to it upon execution.

/etc/conf.d/sshguard is where flags & log path can be passed to the sshguard service.

Rules

/etc/conf.d/sshguard: overly strict rules
SSHGUARD_OPTS="-p 3600 -s 3600 -a 20"

Logs

sshguard will fail to start unless it has proper authorization logs to monitor.

/etc/conf.d/sshguard: syslog-ng log location
SSHGUARD_OPTS="${SSHGUARD_OPTS} -l /var/log/messages"

Iptables

IP v4

Generate blank iptables rules, and start iptables as outlined here.

Insert these rules to allow sshguard to ban malicious users.

# iptables -N sshguard

&& to block all trafic from offenders

# iptables -A INPUT -j sshguard

Boot Service

OpenRC

To start sshguard immediately:

# rc-service sshguard start

To start sshguard upon reboot:

# rc-update add sshguard default

External Resources