#!/bin/sh ################################################################################# # # Lynis # ------------------ # # Copyright 2007-2013, Michael Boelen # Copyright 2007-2021, CISOfy # # Website : https://cisofy.com # Blog : http://linux-audit.com # GitHub : https://github.com/CISOfy/lynis # # Lynis comes with ABSOLUTELY NO WARRANTY. This is free software, and you are # welcome to redistribute it under the terms of the GNU General Public License. # See LICENSE file for usage of this software. # ################################################################################# # # Cryptography # ################################################################################# # RNG_FOUND=0 # ################################################################################# # InsertSection "${SECTION_CRYPTOGRAPHY}" # ################################################################################# # # Test : CRYP-7902 # Description : check for expired SSL certificates if [ -n "${OPENSSLBINARY}" ]; then PREQS_MET="YES"; else PREQS_MET="NO"; fi Register --test-no CRYP-7902 --preqs-met ${PREQS_MET} --weight L --network NO --category security --description "Check expire date of SSL certificates" if [ ${SKIPTEST} -eq 0 ]; then COUNT_EXPIRED=0 COUNT_TOTAL=0 FOUNDPROBLEM=0 SKIP=0 sSSL_PATHS=$(echo ${SSL_CERTIFICATE_PATHS} | ${SEDBINARY} 's/:space:/__space__/g' | ${SEDBINARY} 's/:/ /g') sSSL_PATHS=$(echo ${sSSL_PATHS} | ${SEDBINARY} 's/^ //' | ${SORTBINARY} -u) LogText "Paths to scan: ${sSSL_PATHS}" IGNORE_PATHS_PRINT=$(echo ${SSL_CERTIFICATE_PATHS_TO_IGNORE} | ${SEDBINARY} 's/:/, /g' | ${SEDBINARY} 's/__space__/ /g' | ${SEDBINARY} 's/^ //' | ${SORTBINARY} -u) LogText "Paths to ignore: ${IGNORE_PATHS_PRINT}" for DIR in ${sSSL_PATHS}; do COUNT_DIR=0 if [ -d ${DIR} ]; then FileIsReadable ${DIR} if [ ${CANREAD} -eq 1 ]; then LASTSUBDIR="" LogText "Result: found directory ${DIR}" # Search for certificate files FILES=$(${FINDBINARY} ${DIR} -type f 2> /dev/null | ${EGREPBINARY} ".cer$|.crt$|.der$|.pem$|^cert" | ${SORTBINARY} | ${SEDBINARY} 's/ /__space__/g') for FILE in ${FILES}; do FILE=$(echo ${FILE} | ${SEDBINARY} 's/__space__/ /g') # See if we need to skip this path SUBDIR=$(echo ${FILE} | ${AWKBINARY} -F/ 'sub(FS $NF,x)' | ${SEDBINARY} 's/__space__/ /g') # If we discover a new directory, do evaluation #Debug "File : ${FILE}" #Debug "Lastdir: ${LASTSUBDIR}" #Debug "Curdir : ${SUBDIR}" if [ ! "${SUBDIR}" = "${LASTSUBDIR}" ]; then SKIP=0 # Now check if this path is on the to-be-ignored list for D in ${SSL_CERTIFICATE_PATHS_TO_IGNORE}; do if ContainsString "${D}" "${SUBDIR}"; then SKIP=1 LogText "Result: skipping directory (${SUBDIR}) as it is on ignore list" fi done fi if [ ${SKIP} -eq 0 ]; then #Debug "Testing ${FILE} in path: $SUBDIR" COUNT_DIR=$((COUNT_DIR + 1)) FileIsReadable "${FILE}" if [ ${CANREAD} -eq 1 ]; then # Only check the files that are not installed by a package, unless enabled by profile if [ ${SSL_CERTIFICATE_INCLUDE_PACKAGES} -eq 1 ] || ! FileInstalledByPackage "${FILE}"; then echo ${FILE} | ${EGREPBINARY} -q ".cer$|.der$" CER_DER=$? OUTPUT=$(${GREPBINARY} -q 'BEGIN CERT' "${FILE}") if [ $? -eq 0 -o ${CER_DER} -eq 0 ]; then LogText "Result: file is a certificate file" if [ ${CER_DER} -eq 0 ]; then SSL_DER_OPT="-inform der" else SSL_DER_OPT= fi FIND=$(${OPENSSLBINARY} x509 -noout ${SSL_DER_OPT} -in "${FILE}" -enddate 2> /dev/null | ${GREPBINARY} "^notAfter") if [ $? -eq 0 ]; then # Check certificate where 'end date' has been expired FIND=$(${OPENSSLBINARY} x509 -noout ${SSL_DER_OPT} -checkend 0 -in "${FILE}" -enddate 2> /dev/null) EXIT_CODE=$? CERT_CN=$(${OPENSSLBINARY} x509 -noout ${SSL_DER_OPT} -subject -in "${FILE}" 2> /dev/null | ${SEDBINARY} -e 's/^subject.*CN=\([a-zA-Z0-9\.\-\*]*\).*$/\1/') CERT_NOTAFTER=$(${OPENSSLBINARY} x509 -noout ${SSL_DER_OPT} -enddate -in "${FILE}" 2> /dev/null | ${AWKBINARY} -F= '{if ($1=="notAfter") { print $2 }}') Report "certificate[]=${FILE}|${EXIT_CODE}|cn:${CERT_CN};notafter:${CERT_NOTAFTER};|" if [ ${EXIT_CODE} -eq 0 ]; then LogText "Result: certificate ${FILE} seems to be correct and still valid" else FOUNDPROBLEM=1 COUNT_EXPIRED=$((COUNT_EXPIRED + 1)) LogText "Result: certificate ${FILE} has been expired" fi else LogText "Result: skipping tests for this file (${FILE}) as it is most likely not a certificate (is it a key file?)" fi else LogText "Result: skipping test for this file (${FILE}) as we could not find 'BEGIN CERT'" fi fi else LogText "Result: can not read file ${FILE} (no permission)" fi fi LASTSUBDIR="${SUBDIR}" done COUNT_TOTAL=$((COUNT_TOTAL + COUNT_DIR)) LogText "Result: found ${COUNT_DIR} certificates in ${DIR}" else LogText "Result: can not read path ${DIR} (no permission)" fi else LogText "Result: SSL path ${DIR} does not exist" fi done Report "certificates=${COUNT_TOTAL}" LogText "Result: found a total of ${COUNT_TOTAL} certificates" if [ ${FOUNDPROBLEM} -eq 0 ]; then Display --indent 2 --text "- Checking for expired SSL certificates [${COUNT_EXPIRED}/${COUNT_TOTAL}]" --result "${STATUS_NONE}" --color GREEN else Display --indent 2 --text "- Checking for expired SSL certificates [${COUNT_EXPIRED}/${COUNT_TOTAL}]" --result "${STATUS_FOUND}" --color RED ReportSuggestion "${TEST_NO}" "Check available certificates for expiration" fi fi # ################################################################################# # # Test : CRYP-7930 # Description : Determine if system uses LUKS block device encryption Register --test-no CRYP-7930 --os Linux --weight L --network NO --root-only YES --category security --description "Determine if system uses LUKS block device encryption" if [ ${SKIPTEST} -eq 0 ]; then CRYPTTABFILE="${ROOTDIR}etc/crypttab" FOUND=0 # cryptsetup only works as root if [ -n "${LSBLKBINARY}" ] && [ -n "${CRYPTSETUPBINARY}" ] && [ ${FORENSICS_MODE} -eq 0 ]; then for BLOCK_DEV in $(${LSBLKBINARY} --noheadings --list -o NAME 2> /dev/null | cut -d' ' -f1); do if ${CRYPTSETUPBINARY} isLuks $(${FINDBINARY} /dev/ -name "${BLOCK_DEV}" 2> /dev/null) 2> /dev/null; then LogText "Result: Found LUKS encrypted block device: ${BLOCK_DEV}" Report "encryption[]=luks,block_device,${BLOCK_DEV}" FOUND=$((FOUND +1)) else LogText "Result: block device ${BLOCK_DEV} is not LUKS encrypted" fi done unset BLOCK_DEV # This will enable us to do a test for forensics or when crypsetup/lsblk are not available elif [ -f ${CRYPTTABFILE} ]; then LogText "Result: crypttab (${CRYPTTABFILE}) exists" DATA=$(${GREPBINARY} "^[a-z]" ${CRYPTTABFILE} | ${TRBINARY} -cd '[:alnum:]_\-=,\n\t ' | ${SEDBINARY} 's/[[:blank:]]/__space__/g') for LINE in ${DATA}; do LINE=$(echo ${LINE} | ${SEDBINARY} 's/__space__/ /g') if ContainsString "luks," "${LINE}"; then PARTITION=$(echo ${LINE} | ${AWKBINARY} '{print $1}' | ${AWKBINARY} -F_ '{print $1}') LogText "Result: Found LUKS encryption on partition ${PARTITION}" Report "encryption[]=luks,partition,${PARTITION}" FOUND=$((FOUND +1)) fi done unset DATA LINE PARTITION fi if [ ${FOUND} -gt 0 ]; then Display --indent 2 --text "- Found ${FOUND} LUKS encrypted block devices." --result OK --color WHITE fi unset FOUND fi # ################################################################################# # # Test : CRYP-7931 # Description : Determine if system uses encrypted swap if [ -e "${SWAPONBINARY}" -a -e "${CRYPTSETUPBINARY}" ]; then PREQS_MET="YES"; else PREQS_MET="NO"; fi Register --test-no CRYP-7931 --preqs-met ${PREQS_MET} --os Linux --weight L --network NO --root-only YES --category security --description "Determine if system uses encrypted swap" if [ ${SKIPTEST} -eq 0 ]; then ENCRYPTED_SWAPS=0 UNENCRYPTED_SWAPS=0 # Redirect errors, as RHEL 5/6 and others don't have the --show option SWAPS=$(${SWAPONBINARY} --show=NAME --noheadings 2> /dev/null) if [ $? -eq 0 ]; then for BLOCK_DEV in ${SWAPS}; do if ${CRYPTSETUPBINARY} isLuks "${BLOCK_DEV}" 2> /dev/null; then LogText "Result: Found LUKS encrypted swap device: ${BLOCK_DEV}" ENCRYPTED_SWAPS=$((ENCRYPTED_SWAPS + 1)) Report "encrypted_swap[]=${BLOCK_DEV},LUKS" elif ${CRYPTSETUPBINARY} status "${BLOCK_DEV}" 2> /dev/null | ${GREPBINARY} -q "cipher:"; then LogText "Result: Found non-LUKS encrypted swap device: ${BLOCK_DEV}" ENCRYPTED_SWAPS=$((ENCRYPTED_SWAPS + 1)) Report "encrypted_swap[]=${BLOCK_DEV},other" else LogText "Result: Found unencrypted swap device: ${BLOCK_DEV}" UNENCRYPTED_SWAPS=$((UNENCRYPTED_SWAPS +1)) Report "non_encrypted_swap[]=${BLOCK_DEV}" fi done Display --indent 2 --text "- Found ${ENCRYPTED_SWAPS} encrypted and ${UNENCRYPTED_SWAPS} unencrypted swap devices in use." --result OK --color WHITE else LogText "Result: skipping testing as swapon returned an error." fi fi # ################################################################################# # # Test : CRYP-8002 # Description : Gather available kernel entropy Register --test-no CRYP-8002 --os Linux --weight L --network NO --root-only NO --category security --description "Gather available kernel entropy" if [ ${SKIPTEST} -eq 0 ]; then if [ -f ${ROOTDIR}proc/sys/kernel/random/entropy_avail ]; then DATA=$(${AWKBINARY} '$1 ~ /^[0-9]+$/ {print $1}' ${ROOTDIR}proc/sys/kernel/random/entropy_avail) if [ -n "${DATA}" ]; then LogText "Result: found kernel entropy value of ${DATA}" Report "kernel_entropy=${DATA}" if [ ${DATA} -gt 200 ]; then Display --indent 2 --text "- Kernel entropy is sufficient" --result "${STATUS_YES}" --color GREEN else Display --indent 2 --text "- Kernel entropy is sufficient" --result "${STATUS_NO}" --color YELLOW # TODO - enable suggestion when information on website is available fi fi fi fi # ################################################################################# # # Test : CRYP-8004 # Description : Test for presence of hardware random number generators Register --test-no CRYP-8004 --os Linux --weight L --network NO --root-only NO --category security --description "Presence of hardware random number generators" if [ ${SKIPTEST} -eq 0 ]; then LogText "Test: looking for ${ROOTDIR}sys/class/misc/hw_random/rng_current" if [ -f "${ROOTDIR}sys/class/misc/hw_random/rng_current" ]; then DATA=$(${HEADBINARY} -n 1 ${ROOTDIR}sys/class/misc/hw_random/rng_current | ${TRBINARY} -d '[[:cntrl:]]') if [ "${DATA}" != "none" ]; then LogText "Result: positive match, found RNG: ${DATA}" if IsRunning "rngd"; then Display --indent 2 --text "- HW RNG & rngd" --result "${STATUS_YES}" --color GREEN LogText "Result: rngd is running" RNG_FOUND=1 else Display --indent 2 --text "- HW RNG & rngd" --result "${STATUS_NO}" --color YELLOW # TODO - enable suggestion when website has listing for this control # ReportSuggestion "${TEST_NO}" "Utilize hardware random number generation by running rngd" fi else Display --indent 2 --text "- HW RNG & rngd" --result "${STATUS_NO}" --color YELLOW LogText "Result: no HW RNG available" fi else Display --indent 2 --text "- HW RNG & rngd" --result "${STATUS_NO}" --color RED LogText "Result: could not find ${ROOTDIR}sys/class/misc/hw_random/rng_current" fi fi # ################################################################################# # # Test : CRYP-8005 # Description : Test for presence of software pseudo random number generators Register --test-no CRYP-8005 --os Linux --weight L --network NO --root-only NO --category security --description "Presence of software pseudo random number generators" if [ ${SKIPTEST} -eq 0 ]; then LogText "Test: looking for software pseudo random number generators" FOUND="" for SERVICE in audio-entropyd haveged jitterentropy-rngd; do # Using --full as jitterentropy-rngd would otherwise not match if IsRunning --full "${SERVICE}"; then FOUND="${FOUND} ${SERVICE}" fi done if [ -z "${FOUND}" ]; then Display --indent 2 --text "- SW prng" --result "${STATUS_NO}" --color YELLOW # ReportSuggestion "${TEST_NO}" "Utilize software pseudo random number generators" else RNG_FOUND=1 Display --indent 2 --text "- SW prng" --result "${STATUS_YES}" --color GREEN LogText "Result: found ${FOUND} running" fi fi # ################################################################################# # # Test : CRYP-8006 # Description : Check that the MemoryOverwriteRequest-bit is set to protect against cold-boot attacks Register --test-no CRYP-8006 --os Linux --weight L --network NO --root-only NO --category security --description "MemoryOverwriteRequest-bit set" if [ ${SKIPTEST} -eq 0 ]; then MOR_CONTROL="${ROOTDIR}sys/firmware/efi/efivars/MemoryOverwriteRequestControl-e20939be-32d4-41be-a150-897f85d49829" LogText "Test: looking for ${MOR_CONTROL}" if [ -f "${MOR_CONTROL}" ]; then DATA=$(od -An --skip-bytes=4 "$MOR_CONTROL") if [ "$DATA" = " 000001" ]; then LogText "Result: MOR-bit set" Display --indent 2 --text "MOR-bit set" --result "${STATUS_YES}" --color GREEN elif [ "$DATA" = " 000000" ]; then LogText "Result: MOR-bit not set!" Display --indent 2 --text "MOR-bit set" --result "${STATUS_NO}" --color RED else LogText "Result: MOR-bit unknown. Found: $DATA" Display --indent 2 --text "MOR-bit set" --result "${STATUS_UNKNOWN}" --color YELLOW fi else LogText "Result: could not find ${MOR_CONTROL}" Display --indent 2 --text "- MOR variable not found" --result "${STATUS_WEAK}" --color WHITE fi fi # ################################################################################# # Report "rng_found=${RNG_FOUND}" # ################################################################################# # WaitForKeyPress # #================================================================================ # Lynis - Security Auditing and System Hardening for Linux and UNIX - https://cisofy.com