DNS Gurus
Cached · just now
89/100 SECURITY SCORE

Certificate Information

Subject
CN=books.eliteengineer.org
Issuer
C=US, O=Let's Encrypt, CN=E8
Valid From
January 21, 2026
Valid Until
April 21, 2026 82 days
Public Key
ECDSA 256 bit (P-256) Adequate
Signature Algorithm
ECDSA-SHA384
SHA-256 Fingerprint
4F:11:FB:0B:4A:0E:57:E2:DC:C4:F1:EE:0D:DC:B2:49:42:48:45:6C:82:A4:C4:C0:F1:82:48:6F:55:E5:3B:7D
Alternative Names
52 domains

Security Configuration

TLS Protocols
TLS 1.2 TLS 1.3
Forward Secrecy
Supported (Modern clients use PFS)

HTTP Security Headers

Status
Strict-Transport-Security
Excellent
max-age=64072000; includeSubDomains; preload
Content-Security-Policy
Missing
Not configured
X-Frame-Options
Excellent
DENY
X-Content-Type-Options
Good
nosniff
Referrer-Policy
Missing
Not configured
Permissions-Policy
Missing
Not configured
Recommendations
  • • Add Content-Security-Policy header to prevent XSS attacks
  • • Add Referrer-Policy header (recommended: strict-origin-when-cross-origin)
  • • Consider adding Permissions-Policy to control browser features

CAA Records (Certificate Authority Authorization)

CAA Records
Configured (Restricts certificate issuance)
Current Issuer
Authorized (Matches CAA policy)
Authorized CAs
letsencrypt.org
Recommendations
  • • Consider using critical flag (flags=128) for stricter CAA enforcement
  • • Consider adding 'iodef' records to receive notifications about unauthorized certificate issuance attempts
  • • Consider adding 'issuewild' records to control wildcard certificate issuance