debian-cis/bin/hardening/4.2.2.3_syslog_ng_logfiles_perm.sh

#!/bin/bash

#
# CIS Debian Hardening
#

#
# 4.2.2.3 Create and Set Permissions on syslog-ng Log Files (Scored)
#

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

# Note: this is not exacly the same check as the one described in CIS PDF

# shellcheck disable=2034
HARDENING_LEVEL=3
# shellcheck disable=2034
DESCRIPTION="Create and set permissions on syslog-ng logfiles."

PERMISSIONS=''
USER=''
GROUP=''
EXCEPTIONS=''

# This function will be called if the script status is on enabled / audit mode
audit () {
    FILES=$(grep "file(" "$SYSLOG_BASEDIR"/syslog-ng.conf | grep '"' | cut -d'"' -f 2)
    for FILE in $FILES; do
        does_file_exist "$FILE"
        if [ "$FNRET" != 0 ]; then
            warn "$FILE does not exist"
        else
            FOUND_EXC=0
            if grep -q "$FILE" <(tr ' ' '\n' <<< "$EXCEPTIONS" | cut -d ":" -f 1); then
                debug "$FILE is found in exceptions"
                debug "Setting special user:group:perm"
                FOUND_EXC=1
                local user_bak="$USER"
                local group_bak="$GROUP"
                local perm_bak="$PERMISSIONS"
                USER="$(tr ' ' '\n' <<< "$EXCEPTIONS" | grep "$FILE" | cut -d':' -f 2)"
                GROUP="$(tr ' ' '\n' <<< "$EXCEPTIONS" | grep "$FILE" | cut -d':' -f 3)"
                PERMISSIONS="$(tr ' ' '\n' <<< "$EXCEPTIONS" | grep "$FILE" | cut -d':' -f 4)"
            fi
            has_file_correct_ownership "$FILE" "$USER" "$GROUP"
            if [ "$FNRET" = 0 ]; then
                ok "$FILE has correct ownership ($USER:$GROUP)"
            else
                crit "$FILE ownership was not set to $USER:$GROUP"
            fi
            has_file_correct_permissions "$FILE" "$PERMISSIONS"
            if [ "$FNRET" = 0 ]; then
                ok "$FILE has correct permissions ($PERMISSIONS)"
            else
                crit "$FILE permissions were not set to $PERMISSIONS"
            fi
            if [ "$FOUND_EXC" = 1 ]; then
                debug "Resetting user:group:perm"
                USER="$user_bak"
                GROUP="$group_bak"
                PERMISSIONS="$perm_bak"
            fi
        fi
    done
}

# This function will be called if the script status is on enabled mode
apply () {
    for FILE in $FILES; do
        does_file_exist "$FILE"
        if [ "$FNRET" != 0 ]; then
            info "$FILE does not exist"
            filedir=$(dirname "${FILE#/var/log/}")
            if [ ! "$filedir" = "." ] && [ ! -d /var/log/"$filedir" ]; then
                debug "Creating /var/log/$filedir for $FILE"
                debug "mkdir -p /var/log/$filedir"
                mkdir -p /var/log/"$filedir"
            fi
            touch "$FILE"
        fi
        FOUND_EXC=0
        if grep "$FILE" <(tr ' ' '\n' <<< "$EXCEPTIONS" | cut -d ":" -f 1); then
            debug "$FILE is found in exceptions"
            debug "Setting special user:group:perm"
            FOUND_EXC=1
            local user_bak="$USER"
            local group_bak="$GROUP"
            local perm_bak="$PERMISSIONS"
            USER="$(tr ' ' '\n' <<< "$EXCEPTIONS" | grep "$FILE" | cut -d':' -f 2)"
            GROUP="$(tr ' ' '\n' <<< "$EXCEPTIONS" | grep "$FILE" | cut -d':' -f 3)"
            PERMISSIONS="$(tr ' ' '\n' <<< "$EXCEPTIONS" | grep "$FILE" | cut -d':' -f 4)"
        fi
        has_file_correct_ownership "$FILE" "$USER" "$GROUP"
        if [ "$FNRET" = 0 ]; then
            ok "$FILE has correct ownership"
        else
            warn "fixing $FILE ownership to $USER:$GROUP"
            chown "$USER":"$GROUP" "$FILE"
        fi
        has_file_correct_permissions "$FILE" "$PERMISSIONS"
        if [ "$FNRET" = 0 ]; then
            ok "$FILE has correct permissions"
        else
            info "fixing $FILE permissions to $PERMISSIONS"
            chmod 0"$PERMISSIONS" "$FILE"
        fi
        if [ "$FOUND_EXC" = 1 ]; then
            debug "Resetting user:group:perm"
            USER="$user_bak"
            GROUP="$group_bak"
            PERMISSIONS="$perm_bak"
        fi
    done
}

# This function will create the config file for this check with default values
create_config() {
    cat <<EOF
status=audit
SYSLOG_BASEDIR='/etc/syslog-ng'
PERMISSIONS='640'
USER='root'
GROUP='adm'
# Put exceptions here with file:user:group:permissions
# example: /dev/null:root:root:666
EXCEPTIONS=''
EOF
}

# This function will check config parameters required
check_config() {
    does_user_exist "$USER"
    if [ "$FNRET" != 0 ]; then
        crit "$USER does not exist"
        exit 128
    fi
    does_group_exist $GROUP
    if [ "$FNRET" != 0 ]; then
        crit "$GROUP does not exist"
        exit 128
    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 "$CIS_ROOT_DIR"/lib/main.sh ]; then
    # shellcheck source=/opt/debian-cis/lib/main.sh
    . "$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