#!/bin/bash

#
# harbian-audit for Debian GNU/Linux 7/8/9 or CentOS 8 Hardening
#

#
# 9.2.11 Set deny times for Password Attempts (Scored)
# Replaced pam_tally2 with pam_faillock in debian 11
# The number in the original document is 9.2.2
# for login and ssh service
# Author : Samson wen, Samson <sccxboy@gmail.com>
#

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

HARDENING_LEVEL=3

PACKAGE='libpam-modules-bin'
AUTHFILE='/etc/pam.d/common-auth'
ADDPATTERNLINE='# pam-auth-update(8) for details.'
DENYOPTION='deny'
DENY_VAL=3

# This function will be called if the script status is on enabled / audit mode
audit_before11 () {
    is_pkg_installed $PACKAGE
    if [ $FNRET != 0 ]; then
        crit "$PACKAGE is not installed!"
        FNRET=11
    else
        ok "$PACKAGE is installed"
        does_pattern_exist_in_file $AUTHFILE $AUTHPATTERN
        if [ $FNRET = 0 ]; then
                ok "$AUTHPATTERN is present in $AUTHFILE."
		check_param_pair_by_pam $AUTHFILE $PAMLIBNAME $DENYOPTION le $DENY_VAL
                if [ $FNRET = 0 ]; then
                	ok "$DENYOPTION set condition is less-than-or-equal-to $DENY_VAL"
                else
                    	crit "$DENYOPTION set condition is not $DENY_VAL"
                fi
        else
            crit "$AUTHPATTERN is not present in $AUTHFILE"
            FNRET=2
        fi
    fi
}

audit_debian11 () {
    is_pkg_installed $PACKAGE
    if [ $FNRET != 0 ]; then
        crit "$PACKAGE is not installed!"
        FNRET=11
    else
        ok "$PACKAGE is installed"
        does_pattern_exist_in_file $AUTHFILE $AUTHPATTERN
        if [ $FNRET = 0 ]; then
                ok "$AUTHPATTERN is present in $AUTHFILE."
                check_param_pair_by_value $SECCONFFILE $DENYOPTION le $DENY_VAL
		if [ $FNRET = 0 ]; then
			ok "Option $DENYOPTION set condition is less than or equal to $DENY_VAL in $SECCONFFILE"
		elif [ $FNRET = 1 ]; then
			crit "Option $DENYOPTION set condition is greater than $DENY_VAL in $SECCONFFILE"
		elif [ $FNRET = 2 ]; then
			crit "Option $DENYOPTION is not conf in $SECCONFFILE"
		elif [ $FNRET = 3 ]; then
			crit "Config file $SECCONFFILE is not exist!"
    		fi
	else
            crit "$AUTHPATTERN is not present in $AUTHFILE"
            FNRET=12
	fi
    fi
}

audit () {
	if [ $ISDEBIAN11 = 1 ]; then
		audit_debian11
	else
		audit_before11
	fi
}

apply_before11 () {
    if [ $FNRET = 0 ]; then
		ok "$DENYOPTION set condition is less-than-or-equal-to $DENY_VAL"
    elif [ $FNRET = 11 ]; then
        warn "Apply:$PACKAGE is absent, installing it"
        install_package $PACKAGE
    elif [ $FNRET = 2 ]; then
        warn "Apply:$AUTHPATTERN is not present in $AUTHFILE"
		if [ $OS_RELEASE -eq 2 ]; then
			add_line_file_after_pattern_lastline "$AUTHFILE" "$AUTHRULE" "$ADDPATTERNLINE"
		else
			add_line_file_after_pattern "$AUTHFILE" "$AUTHRULE" "$ADDPATTERNLINE"
		fi
    elif [ $FNRET = 3 ]; then
        crit "$AUTHFILE is not exist, please check"
    elif [ $FNRET = 4 ]; then
        warn "Apply:$DENYOPTION is not conf"   
        add_option_to_auth_check $AUTHFILE $PAMLIBNAME "$DENYOPTION=$DENY_VAL"
    elif [ $FNRET = 5 ]; then                                                
        warn "Apply:$DENYOPTION set is not match legally, reset it to $DENY_VAL"
        reset_option_to_password_check $AUTHFILE $PAMLIBNAME "$DENYOPTION" "$DENY_VAL"
    fi
}

# Input: 
# Param1: return-value of call check_param_pair_by_value
# Function: Perform corresponding repair actions based on the return value of the error. 
apply_secconffile() {
	FNRET=$1
	if [ $FNRET = 0 ]; then
		ok "Option $DENYOPTION set condition is less than or equal to $DENY_VAL in $SECCONFFILE"
	elif [ $FNRET = 1 ]; then
		warn "Reset option $DENYOPTION to $DENY_VAL in $SECCONFFILE"
		replace_in_file $SECCONFFILE "^$DENYOPTION.*" "$DENYOPTION = $DENY_VAL"
	elif [ $FNRET = 2 ]; then
		warn "$DENYOPTION is not conf, add to $SECCONFFILE"
		add_end_of_file $SECCONFFILE "$DENYOPTION = $DENY_VAL"
	elif [ $FNRET = 3 ]; then
		warn "Config file $SECCONFFILE is not exist! Please check it by youself"
	else
		warn "This param $FNRET was not defined!!!"
	fi
}

apply_debian11 () {
	if [ $FNRET = 0 ]; then
		ok "$DENYOPTION set condition is less than or equal to $DENY_VAL in $SECCONFFILE"
    	elif [ $FNRET = 11 ]; then
        	warn "Apply:$PACKAGE is absent, installing it"
        	install_package $PACKAGE
        	does_pattern_exist_in_file $AUTHFILE $AUTHPATTERN
        	if [ $FNRET != 0 ]; then
			add_line_file_after_pattern "$AUTHFILE" "$AUTHRULE" "$ADDPATTERNLINE"
                	check_param_pair_by_value $SECCONFFILE $DENYOPTION le $DENY_VAL
			apply_secconffile $FNRET
		fi
    	elif [ $FNRET = 12 ]; then
		add_line_file_after_pattern "$AUTHFILE" "$AUTHRULE" "$ADDPATTERNLINE"
                check_param_pair_by_value $SECCONFFILE $DENYOPTION le $DENY_VAL
		apply_secconffile $FNRET
	else
		apply_secconffile $FNRET
	fi
}

# This function will be called if the script status is on enabled mode
apply () {
	if [ $ISDEBIAN11 = 1 ]; then
		apply_debian11
	else
		apply_before11
	fi
}

# This function will check config parameters required
check_config() {
	if [ $OS_RELEASE -eq 2 ]; then
		PACKAGE='pam'
		PAMLIBNAME='pam_failloc.so'
		AUTHPATTERN='^auth[[:space:]]*required[[:space:]]*pam_failloc.so'
		AUTHFILE='/etc/pam.d/password-auth'
		AUTHRULE='auth    required pam_failloc.so deny=3 even_deny_root unlock_time=900'
		ADDPATTERNLINE='auth[[:space:]]*required'
	else
		is_debian_11
		# faillock for Debian 11 
                if [ $FNRET = 0 ]; then
			ISDEBIAN11=1
			SECCONFFILE='/etc/security/faillock.conf'
			AUTHPATTERN='^auth[[:space:]]*required[[:space:]]*pam_faillock.so'
			AUTHRULE='auth    required pam_faillock.so'
		else
			ISDEBIAN11=0
			PAMLIBNAME='pam_tally2.so'
			AUTHPATTERN='^auth[[:space:]]*required[[:space:]]*pam_tally2.so'
			AUTHRULE='auth    required pam_tally2.so deny=3 even_deny_root unlock_time=900'
		fi
	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