Ensure Signing Keys are Generated with a Secure Algorithm

低レベル 2自動bind

説明

When Zone Signing Keys (ZSK) or Key Signing Keys (KSK) are generated there are several secure DNSSEC digital signature algorithms that are recommended. The algorithms are listed below with the standard DNSSEC algorithm number followed by the common name, and then the BIND 9 mnemonic name used by dnssec-keygen. The audit reads the Algorithm: line of every K*.private key file under $BIND_HOME and requires RSASHA256 (8), RSASHA512 (10), ECDSAP256SHA256 (13), ECDSAP384SHA384 (14) or ED25519 (15).

チェック方法

監査方法: シェルコマンド

shell

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 $BH /etc/bind/keys -name 'K*.private' -type f 2>/dev/null | sort -u)
[ -n "$keys" ] || { echo compliant; exit 0; }
bad=$(for k in $keys; do a=$(awk '/^Algorithm:/{print $2; exit}' "$k"); case "$a" in 8|10|13|14|15) ;; *) echo "$k: algorithm ${a:-unknown}" ;; esac; done)
[ -z "$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 remediate a weak key, perform the following: ; Generate a new key to replace the weak key using dnssec-keygen and one of the recommended algorithms. Examples commands are shown below. # dnssec-keygen -a RSASHA256 -b 2048 example.com # dnssec-keygen -a ECDSAP384SHA384 cisecurity.org ; Implement a rollover period to phase out the weak key and replace it with the newly generated key. ; Once the key is fully deleted from active use, remove the file.

プロパティ

オペレーティングシステム: すべて
タグ: binddnsdnssec
参照: CIS ISC BIND DNS Server 9.11 Benchmark v1.0.0 - 8.2 Ensure Signing Keys are Generated with a Secure Algorithm

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。

shell

tmaegis scan --target bind --level 2