debian-cis/bin/hardening/5.6_restrict_su.sh

#!/bin/bash

# run-shellcheck
#
# CIS Debian Hardening
#

#
# 5.6 Ensure access to the su command is restricted (Scored)
#

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

# shellcheck disable=2034
HARDENING_LEVEL=3
# shellcheck disable=2034
DESCRIPTION="Restrict access to su command."

PACKAGE='login'
PATTERN='^auth[[:space:]]*required[[:space:]]*pam_wheel.so'
FILE='/etc/pam.d/su'

# This function will be called if the script status is on enabled / audit mode
audit() {
    is_pkg_installed "$PACKAGE"
    if [ "$FNRET" != 0 ]; then
        crit "$PACKAGE is not installed!"
    else
        ok "$PACKAGE is installed"
        does_pattern_exist_in_file "$FILE" "$PATTERN"
        if [ "$FNRET" = 0 ]; then
            ok "$PATTERN is present in $FILE"
        else
            crit "$PATTERN is not present in $FILE"
        fi
    fi
}

# This function will be called if the script status is on enabled mode
apply() {
    is_pkg_installed "$PACKAGE"
    if [ "$FNRET" = 0 ]; then
        ok "$PACKAGE is installed"
    else
        crit "$PACKAGE is absent, installing it"
        apt_install "$PACKAGE"
    fi
    does_pattern_exist_in_file "$FILE" "$PATTERN"
    if [ "$FNRET" = 0 ]; then
        ok "$PATTERN is present in $FILE"
    else
        crit "$PATTERN is not present in $FILE"
        add_line_file_before_pattern $FILE "auth       required   pam_wheel.so" "# Uncomment this if you want wheel members to be able to"
    fi
}

# This function will check config parameters required
check_config() {
    :
}

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

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