BIND DNS
TMA-BIND-8.2
Ensure Signing Keys are Generated with a Secure Algorithm
Descripción
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 $BIND_HOME and requires RSASHA256 (8), RSASHA512 (10), ECDSAP256SHA256 (13), ECDSAP384SHA384 (14) or ED25519 (15).
Cómo se verifica
Método de auditoría: Comando de shell
BH=''; for d in /var/named /etc/bind /var/cache/bind; do [ -d "$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"- Salida esperada
compliant
Cómo se corrige
Método de corrección: Guía o parche de infraestructura
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.
Propiedades
- Sistemas operativos
- Cualquiera
- Etiquetas
- binddnsdnssec
- Referencia
- CIS ISC BIND DNS Server 9.11 Benchmark v1.0.0 - 8.2 Ensure Signing Keys are Generated with a Secure Algorithm
Verificar este host
Ejecute esto en un equipo que tenga permiso para auditar. El escaneo es de solo lectura.
tmaegis scan --target bind --level 2