DNS Gurus
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85/100 SECURITY SCORE

Certificate Information

Subject
CN=hateblo.jp
Issuer
C=US, O=Let's Encrypt, CN=E8
Valid From
December 10, 2025
Valid Until
March 10, 2026 88 days
Public Key
ECDSA 256 bit (P-256) Adequate
Signature Algorithm
ECDSA-SHA384
SHA-256 Fingerprint
94:56:F2:C1:95:91:0F:C6:F9:79:6F:36:1D:9F:F3:9E:9B:F0:6B:7A:E2:BC:35:6C:5A:48:A3:C5:40:51:C5:8A
Alternative Names
22 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
Present
max-age=2592000;
Content-Security-Policy
Weak
frame-ancestors; upgrade-insecure-requests
X-Frame-Options
Excellent
DENY
X-Content-Type-Options
Good
nosniff
Referrer-Policy
Missing
Not configured
Permissions-Policy
Missing
Not configured
Recommendations
  • • Increase HSTS max-age to at least 1 year and add includeSubDomains
  • • Significantly strengthen CSP directives
  • • 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
Not Configured (Any CA can issue certificates)
CAA Issues
  • • No CAA records configured - any CA can issue certificates
Recommendations
  • • Implement CAA records to restrict which CAs can issue certificates for your domain
  • • This adds an extra layer of security against unauthorized certificate issuance
  • • Example: Add CAA record 'example.com. CAA 0 issue "letsencrypt.org"'
  • • Consider adding 'iodef' record to receive security incident reports