Ensure OCSP Stapling Is Enabled

LowLevel 2Automatedapache

Description

The OCSP (Online Certificate Status Protocol) provides the current revocation status of an X.509 certificate and allows for a certificate authority to revoke the validity of a signed certificate before its expiration date. The URI for the OCSP server is included in the certificate and verified by the browser. SSLUseStapling on must be set (no occurrence off) and an SSLStaplingCache must be configured. Reads the main configuration (APACHE_CONF overrides; default /etc/apache2/apache2.conf, /etc/httpd/conf/httpd.conf or /usr/local/apache2/conf/httpd.conf) and every Include/IncludeOptional file. CIS marks this recommendation Manual; the automated check implements its audit procedure.

How it is checked

Audit method: Shell command

shell

c=${APACHE_CONF:-}; if [ -z "$c" ]; then for f in /etc/apache2/apache2.conf /etc/httpd/conf/httpd.conf /usr/local/apache2/conf/httpd.conf /etc/apache2/httpd.conf; do [ -f "$f" ] && { c=$f; break; }; done; fi; [ -r "$c" ] || exit 1; R=$(awk 'tolower($1)=="serverroot"{v=$2; gsub(/"/,"",v); print v; exit}' "$c"); [ -n "$R" ] || R=$(dirname "$c"); shopt -s nocasematch; inc(){ local p g l; [ ${#FUNCNAME[@]} -lt 16 ] || return 0; p=$1; case $p in /*) ;; *) p=$R/$p;; esac; [ -d "$p" ] && p="$p/*"; for g in $p; do [ -f "$g" ] || continue; while IFS= read -r l || [ -n "$l" ]; do if [[ $l =~ ^[[:space:]]*include(optional)?[[:space:]]+\"?([^\"[:space:]]+) ]]; then inc "${BASH_REMATCH[2]}"; else printf '%s\n' "$l"; fi; done < "$g"; done; }; cfg=$(inc "$c" | sed -e 's/^[[:space:]]*//' -e '/^#/d' -e '/^$/d'); shopt -u nocasematch; printf '%s\n' "$cfg" | awk 'tolower($1)=="sslusestapling"{n++; if(tolower($2)!="on") bad=1} tolower($1)=="sslstaplingcache"{c=1} END{print (n>0&&c&&!bad)?"compliant":"noncompliant"}'

Expected output: compliant

How it is fixed

Fix method: Guidance or infrastructure patch

At server level: SSLStaplingCache "shmcb:logs/ssl_staple_cache(512000)" and SSLUseStapling On (also in each TLS virtual host). Then run apachectl configtest and reload Apache.

Properties

Operating systems: Any
Tags: apachetls
Reference: CIS Apache HTTP Server 2.4 Benchmark v2.4.0 - 7.10 Ensure OCSP Stapling Is Enabled

Check this host

Run this on a machine you are allowed to audit. The scan is read-only.

shell

tmaegis scan --target apache --level 2