#!/bin/bash

#
# harbian-audit for Debian GNU/Linux 9/10 or CentOS 8 Hardening
#

#
# 4.6 Activate SELinux (Scored)
# Add by Author : Samson-W (samson@hardenedlinux.org)
#

set -e # One error, it's over
set -u # One variable unset, it's over

HARDENING_LEVEL=3

PACKAGES='selinux-basics selinux-policy-default'
SETSTRING="security=selinux" 
PROC_CMDLINE='/proc/cmdline'
SELINUXCONF_FILE='/etc/selinux/config'
SELINUXENFORCE_MODE='SELINUX=enforcing'
LSM_RUN_STATUS_FILE='/sys/kernel/security/lsm'

audit_debian () {
	check_aa_status
	if [ $FNRET = 0 ]; then
		ok "AppArmor was actived. So pass."
		return 0
	fi
	for PACKAGE in ${PACKAGES}
	do
		is_pkg_installed $PACKAGE
		if [ $FNRET != 0 ]; then
			crit "$PACKAGE is absent!"
			FNRET=1
			return 
		fi
	done
	if [ $FNRET = 0 ]; then
		ok "$PACKAGE is installed"
	fi
	if [ $(grep -c "${SETSTRING}" $PROC_CMDLINE) -eq 1 ]; then
		ok "SELinux is actived."
		does_valid_pattern_exist_in_file $SELINUXCONF_FILE $SELINUXENFORCE_MODE
		if [ ${FNRET} -eq 0 -a $(getenforce | grep -c 'Enforcing') -eq 1 ]; then
			ok "SELinux is in Enforcing mode."
			FNRET=0
		else	
			crit "SELinux is not in Enforcing mode."
			FNRET=3
			return 
		fi
	else	
		crit "SELinux is inactived."
		FNRET=2
		return
	fi
}

audit_centos () {
	for PACKAGE in ${PACKAGES}
	do
		is_pkg_installed $PACKAGE
		if [ $FNRET != 0 ]; then
			crit "$PACKAGE is absent!"
			FNRET=1
		else
			FNRET=0
		fi
	done
	if [ $FNRET -eq 0 ]; then
		if [ $(grep -c selinux $LSM_RUN_STATUS_FILE) -eq 1 ]; then
			ok "SELinux was activated."
			does_valid_pattern_exist_in_file $SELINUXCONF_FILE $SELINUXENFORCE_MODE
			if [ ${FNRET} -eq 0 -a $(getenforce | grep -c 'Enforcing') -eq 1 ]; then
				ok "SELinux is in Enforcing mode."
				FNRET=0
			else
				crit "SELinux is not in Enforcing mode."
				FNRET=3
			fi
		else
			crit "SELinux is inactived."
			FNRET=2
		fi
	else
		crit "SELinux related packages are not installed."
		FNRET=1
	fi
}

# This function will be called if the script status is on enabled / audit mode
audit () {
	if [ $OS_RELEASE -eq 1 ]; then
        audit_debian
    elif [ $OS_RELEASE -eq 2 ]; then
        audit_centos
    else
        crit "Current OS is not support!"
        FNRET=44
    fi
}

apply_debian () {
	check_aa_status
	if [ $FNRET = 0 ]; then
		ok "AppArmor was actived. So pass."
		return 0
	fi
	case $FNRET in 
		0)	ok "SELinux is active and in Enforcing mode."
			;;
		1)	warn "$PACKAGE is not installed, install $PACKAGES"
        	for PACKAGE in ${PACKAGES}
        	do
            	install_package $PACKAGE
        	done
			warn "Set SELinux to activate, and need reboot"
			selinux-activate
			warn "Set SELinux to enforcing mode, and need reboot"
			replace_in_file $SELINUXCONF_FILE 'SELINUX=.*' $SELINUXENFORCE_MODE
			;;
		2)	warn "Set SELinux to activate, and need reboot"
			selinux-activate
			warn "Set SELinux to enforcing mode, and need reboot"
			replace_in_file $SELINUXCONF_FILE 'SELINUX=.*' $SELINUXENFORCE_MODE
			;;
		3)	warn "Set SELinux to enforcing mode, and need reboot"
			replace_in_file $SELINUXCONF_FILE 'SELINUX=.*' $SELINUXENFORCE_MODE
			;;
	esac
}

apply_centos () {
    if [ $FNRET = 0 ]; then
		ok "SELinux is active and in Enforcing mode."
    elif [ $FNRET = 1 ]; then
        warn "$PACKAGE is not installed, install $PACKAGES"
        for PACKAGE in ${PACKAGES}
        do
            install_package $PACKAGE
        done
    elif [ $FNRET = 2 ]; then
		warn "Set SELinux to activate, and need reboot"
    elif [ $FNRET = 3 ]; then
		warn "Set SELinux to enforcing mode, and need reboot"
		replace_in_file $SELINUXCONF_FILE 'SELINUX=.*' $SELINUXENFORCE_MODE
	else
		:
	fi
}

# This function will be called if the script status is on enabled mode
apply () {
	if [ $OS_RELEASE -eq 1 ]; then
        apply_debian
    elif [ $OS_RELEASE -eq 2 ]; then
        apply_centos
    else
        crit "Current OS is not support!"
    fi
}

# This function will check config parameters required
check_config() {
	if [ $OS_RELEASE -eq 2 ]; then
		PACKAGES='libselinux libselinux-utils selinux-policy-targeted'
	else
		:
	fi
}

# Source Root Dir Parameter
if [ -r /etc/default/cis-hardening ]; then
    . /etc/default/cis-hardening
fi
if [ -z "$CIS_ROOT_DIR" ]; then
     echo "There is no /etc/default/cis-hardening file nor cis-hardening directory in current environment."
     echo "Cannot source CIS_ROOT_DIR variable, aborting."
    exit 128
fi

# Main function, will call the proper functions given the configuration (audit, enabled, disabled)
if [ -r $CIS_ROOT_DIR/lib/main.sh ]; then
    . $CIS_ROOT_DIR/lib/main.sh
else
    echo "Cannot find main.sh, have you correctly defined your root directory? Current value is $CIS_ROOT_DIR in /etc/default/cis-hardening"
    exit 128
fi