Ensure Signing Keys are Scheduled to be Replaced Periodically

낮음레벨 2자동bind

설명

Implement a periodic key rollover process for both the Zone Signing Keys (ZSK) and the Key Signing Keys (KSK). The ZSK should be replaced within 2 years or less. The KSK should be replaced within 6 years or less. Keys are replaced by generating a new key before the existing key expires, and scheduling a rollover date when the new key will phase out and replace the old key. The audit reads activation dates with dnssec-settime -u -pA and requires ZSKs (DNSKEY 256) activated within the last 2 years and KSKs (DNSKEY 257) within 6 years.

점검 방법

감사 방식: 셸 명령

shell

command -v dnssec-settime >/dev/null 2>&1 || exit 1
BH=''; for d in /var/named /etc/bind /var/cache/bind; do [ -d "$d" ] && BH="$BH $d"; done
[ -n "$BH" ] || { echo 'no BIND directory found'; exit 1; }
RUN=''; for d in /run/named /var/run/named; do [ -d "$d" ] && { RUN=$d; break; }; done
G='-group root'; U='-user root'; for a in named bind; do grep -q "^$a:" /etc/group 2>/dev/null && G="$G -o -group $a"; grep -q "^$a:" /etc/passwd 2>/dev/null && U="$U -o -user $a"; done
RT='^(/var/named(/chroot/var/named)?/(dynamic|slaves|data)|/var/named/chroot/(var/)?run/named|/var/named/chroot/var/log|/var/named/chroot/(var/)?tmp|/var/cache/bind|/run/named|/var/run/named)(/|$)'
keys=$(find $BH /etc/bind/keys -name 'K*.key' -type f 2>/dev/null | sort -u)
[ -n "$keys" ] || { echo compliant; exit 0; }
now=$(date +%s)
bad=$(for k in $keys; do
  if grep -q 'DNSKEY 256 3' "$k"; then lim=63072000; elif grep -q 'DNSKEY 257 3' "$k"; then lim=189216000; else continue; fi
  a=$(dnssec-settime -u -pA "$k" 2>/dev/null | awk '{print $NF; exit}')
  case "$a" in ''|*[!0-9]*) echo "$k: no activation date" ;; *) [ $((now - a)) -le $lim ] || echo "$k: activated $(( (now - a) / 86400 )) days ago" ;; esac
done)
[ -z "$bad" ] && echo compliant || printf '%s\n' "$bad"

예상 출력: compliant

조치 방법

조치 방식: 가이드 또는 인프라 패치

To replace an aged key, perform the following: ; Generate a new key to replace the old key using dnssec-keygen and one of the recommended algorithms. An example command is shown below: # dnssec-keygen -a ED25519 example.org # dnssec-keygen -a ED25519 -f KSK example.org ; Implement a rollover period to phase out the old key and replace it with the newly generated key. The older key should have dates set for the keys to be inactive and then deleted. # dnssec-settime -I +30d -D +60d Kexample.org.+013+46651.key ; Once the date for key deletion has passed, and the key is no longer included in the zone, then remove the key files.

속성

운영 체제: 모두
태그: binddnsoperations
참고 자료: CIS ISC BIND DNS Server 9.11 Benchmark v1.0.0 - 9.6 Ensure Signing Keys are Scheduled to be Replaced Periodically

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감사 권한이 있는 시스템에서 실행하세요. 스캔은 읽기 전용입니다.

shell

tmaegis scan --target bind --level 2