#!/bin/bash
# pki-health-check.sh - Daily PKI check
 
echo "=== PKI Health Check $(date -Iseconds) ==="
 
# 1. Check CA certificates
echo -e "\n[1] CA Certificates:"
for ca in /etc/pki/CA/ca-*.pem; do
    days=$(( ($(openssl x509 -enddate -noout -in "$ca" | cut -d= -f2 | date -f - +%s) - $(date +%s)) / 86400 ))
    status="OK"
    [ "$days" -lt 365 ] && status="WARNING"
    [ "$days" -lt 90 ] && status="CRITICAL"
    echo "  $(basename $ca): $days days [$status]"
done
 
# 2. CRL validity
echo -e "\n[2] CRL Status:"
for crl in /var/www/pki/*.crl; do
    next=$(openssl crl -in "$crl" -nextupdate -noout 2>/dev/null | cut -d= -f2)
    if [ -n "$next" ]; then
        days=$(( ($(date -d "$next" +%s) - $(date +%s)) / 86400 ))
        status="OK"
        [ "$days" -lt 3 ] && status="WARNING"
        [ "$days" -lt 1 ] && status="CRITICAL"
        echo "  $(basename $crl): $days days until update [$status]"
    fi
done
 
# 3. OCSP Responder
echo -e "\n[3] OCSP Responder:"
ocsp_status=$(curl -s -o /dev/null -w "%{http_code}" http://ocsp.example.com/status)
[ "$ocsp_status" = "200" ] && echo "  Status: OK" || echo "  Status: ERROR ($ocsp_status)"
 
# 4. Expiring certificates (30 days)
echo -e "\n[4] Expiring Certificates (<30 days):"
count=$(find /etc/ssl/certs -name "*.pem" -exec openssl x509 -checkend 2592000 -noout -in {} \; 2>/dev/null | grep -c "will expire")
echo "  Count: $count"
 
# 5. Disk space
echo -e "\n[5] Disk Space:"
df -h /etc/pki /var/log | tail -n +2
 
echo -e "\n=== End Health Check ==="

# Root CA validity
openssl x509 -in /etc/pki/CA/root-ca.pem -enddate -noout
# Expected result: > 10 years
 
# Intermediate CA validity
openssl x509 -in /etc/pki/CA/intermediate-ca.pem -enddate -noout
# Expected result: > 2 years
 
# Verify certificate chain
openssl verify -CAfile /etc/pki/CA/root-ca.pem /etc/pki/CA/intermediate-ca.pem
# Expected result: OK

Thresholds:

# CRL metadata
openssl crl -in /var/www/pki/crl.pem -text -noout | head -20
 
# Check Next Update
openssl crl -in /var/www/pki/crl.pem -nextupdate -noout
 
# Fetch CRL from CDP
curl -s http://crl.example.com/crl.der | openssl crl -inform DER -text -noout

Thresholds:

# OCSP availability
curl -s -o /dev/null -w "HTTP: %{http_code}, Time: %{time_total}s\n" http://ocsp.example.com/status
 
# OCSP response for test certificate
openssl ocsp \
    -issuer /etc/pki/CA/intermediate-ca.pem \
    -cert /etc/ssl/certs/test.pem \
    -url http://ocsp.example.com \
    -resp_text
# Expected result: "Cert Status: good" (or "revoked" if revoked)

Thresholds:

# Server certificates (30 days)
find /etc/ssl/certs -name "*.pem" -exec sh -c '
    if openssl x509 -checkend 2592000 -noout -in "$1" 2>/dev/null | grep -q "will expire"; then
        echo "EXPIRING: $1"
    fi
' _ {} \;
 
# CA certificates (1 year)
for ca in /etc/pki/CA/*.pem; do
    if openssl x509 -checkend 31536000 -noout -in "$ca" 2>/dev/null | grep -q "will expire"; then
        echo "CA WARNING: $ca"
    fi
done

# PowerShell: Expiring certificates
Get-ChildItem Cert:\LocalMachine\My | Where-Object {
    $_.NotAfter -lt (Get-Date).AddDays(30)
} | Format-Table Subject, NotAfter, Thumbprint -AutoSize

# Disk space for PKI directories
df -h /etc/pki /var/log/pki /var/www/pki
 
# Log file sizes
du -sh /var/log/pki/*
 
# Processes
ps aux | grep -E "(ocsp|openssl)"

Thresholds:

# /etc/cron.d/pki-health-check
# Daily at 08:00
0 8 * * * root /usr/local/bin/pki-health-check.sh | mail -s "PKI Health Check $(date +%Y-%m-%d)" pki-team@example.com

# prometheus-pki-exporter.yml
- job_name: 'pki'
  static_configs:
    - targets: ['pki-server:9115']
  metrics_path: /probe
  params:
    module: [certificate]

Legend:

• OK - Green
• WARN - Yellow
• CRITICAL - Red

• Renew Certificate - For expiring certificates
• Expiry Monitoring - Automated monitoring
• Alerting Setup - Notifications

« <- Revoke Certificate | -> Operator Scenarios »

Wolfgang van der Stille @ EMSR DATA d.o.o. - Post-Quantum Cryptography Professional