BIND DNS
TMA-BIND-9.6
Ensure Signing Keys are Scheduled to be Replaced Periodically
説明
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.
チェック方法
監査方法: シェルコマンド
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"- 期待される出力
compliant
修正方法
修正方法: ガイダンスまたは IaC パッチ
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.
プロパティ
- オペレーティングシステム
- すべて
- タグ
- binddnsoperations
- 参照
- CIS ISC BIND DNS Server 9.11 Benchmark v1.0.0 - 9.6 Ensure Signing Keys are Scheduled to be Replaced Periodically
このホストをチェック
監査が許可されているマシンで実行してください。スキャンは読み取り専用です。
tmaegis scan --target bind --level 2