debian-cis/bin/hardening/99.5.2.2_ssh_cry_rekey.sh
2020-12-22 16:36:35 +01:00

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#!/bin/bash
# run-shellcheck
#
# Legacy CIS Debian Hardening
#
#
# 99.5.2.2 Checking rekey limit for time (6 hours) or volume (512Mio) whichever comes first.
#
set -e # One error, it's over
set -u # One variable unset, it's over
# shellcheck disable=2034
HARDENING_LEVEL=2
# shellcheck disable=2034
DESCRIPTION="Checking rekey limit for time (6 hours) or volume (512Mio) whichever comes first."
PACKAGE='openssh-server'
OPTIONS='RekeyLimit=512M\s+6h'
FILE='/etc/ssh/sshd_config'
# This function will be called if the script status is on enabled / audit mode
audit() {
get_debian_major_version
set +u
debug "Debian version : $DEB_MAJ_VER "
if [[ -z $DEB_MAJ_VER ]]; then
set -u
crit "Cannot get Debian version. Aborting..."
return
fi
if [[ "${DEB_MAJ_VER}" -lt "8" ]]; then
set -u
warn "Debian version too old (${DEB_MAJ_VER}), check does not apply, you should disable this check."
return
fi
set -u
is_pkg_installed "$PACKAGE"
if [ "$FNRET" != 0 ]; then
crit "$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
# shellcheck disable=SC2001
SSH_VALUE=$(sed 's/\\s+/ /' <<<"$SSH_VALUE")
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 $SSH_VALUE"
fi
/etc/init.d/ssh reload >/dev/null 2>&1
fi
done
}
# This function will check config parameters required
check_config() {
:
}
# Source Root Dir Parameter
if [ -r /etc/default/cis-hardening ]; then
# shellcheck source=../../debian/default
. /etc/default/cis-hardening
fi
if [ -z "$CIS_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