debian-cis/bin/hardening/5.2.22_configure_ssh_max_startups.sh
Thibault Ayanides d110a2aa19 Ignore case for sshd conf
fix #85
2021-04-02 09:25:41 +02:00

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#!/bin/bash
# run-shellcheck
#
# CIS Debian Hardening
#
#
# 5.2.22 Ensure SSH MaxStartups is configured (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="Configure SSHMaxStartups."
PACKAGE='openssh-server'
OPTIONS=''
FILE='/etc/ssh/sshd_config'
# This function will be called if the script status is on enabled / audit mode
audit() {
is_pkg_installed "$PACKAGE"
if [ "$FNRET" != 0 ]; then
ok "$PACKAGE is not installed!"
else
ok "$PACKAGE is installed"
for SSH_OPTION in $OPTIONS; do
SSH_PARAM=$(echo "$SSH_OPTION" | cut -d= -f 1)
SSH_VALUE=$(echo "$SSH_OPTION" | cut -d= -f 2)
PATTERN="^${SSH_PARAM}[[:space:]]*$SSH_VALUE"
does_pattern_exist_in_file_nocase $FILE "$PATTERN"
if [ "$FNRET" = 0 ]; then
ok "$PATTERN is present in $FILE"
else
crit "$PATTERN is not present in $FILE"
fi
done
fi
}
# This function will be called if the script status is on enabled mode
apply() {
is_pkg_installed "$PACKAGE"
if [ "$FNRET" = 0 ]; then
ok "$PACKAGE is installed"
else
crit "$PACKAGE is absent, installing it"
apt_install "$PACKAGE"
fi
for SSH_OPTION in $OPTIONS; do
SSH_PARAM=$(echo "$SSH_OPTION" | cut -d= -f 1)
SSH_VALUE=$(echo "$SSH_OPTION" | cut -d= -f 2)
PATTERN="^${SSH_PARAM}[[:space:]]*$SSH_VALUE"
does_pattern_exist_in_file_nocase "$FILE" "$PATTERN"
if [ "$FNRET" = 0 ]; then
ok "$PATTERN is present in $FILE"
else
warn "$PATTERN is not present in $FILE, adding it"
does_pattern_exist_in_file_nocase "$FILE" "^${SSH_PARAM}"
if [ "$FNRET" != 0 ]; then
add_end_of_file "$FILE" "$SSH_PARAM $SSH_VALUE"
else
info "Parameter $SSH_PARAM is present but with the wrong value -- Fixing"
replace_in_file "$FILE" "^${SSH_PARAM}[[:space:]]*.*" "$SSH_PARAM $SSH_VALUE"
fi
/etc/init.d/ssh reload
fi
done
}
# This function will check config parameters required
check_config() {
:
}
# This function will check config parameters required
create_config() {
cat <<EOF
status=audit
# Value of maxstartups
# 0: Number of unauthenticated connections before we start dropping
# 30: Percentage chance of dropping once we reach 10 (increases linearly for more than 10)
# 60: Maximum number of connections at which we start dropping everything
# Settles sshd maxstartups
OPTIONS='maxstartups=10:30:60'
EOF
}
# Source Root Dir Parameter
if [ -r /etc/default/cis-hardening ]; then
# shellcheck source=../../debian/default
. /etc/default/cis-hardening
fi
if [ -z "$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 "$CIS_ROOT_DIR"/lib/main.sh ]; then
# shellcheck source=../../lib/main.sh
. "$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