86/100 SECURITY SCORE

Certificate Information

Subject
CN=readme.io
Issuer
C=US, O=Google Trust Services, CN=WE1
Valid From
November 17, 2025
Valid Until
February 15, 2026 85 days
Public Key
ECDSA 256 bit (P-256) Adequate
Signature Algorithm
ECDSA-SHA256
SHA-256 Fingerprint
64:CE:80:06:28:75:77:89:26:A5:DE:88:F8:05:D4:58:7F:F9:45:37:CA:81:25:F8:5C:0A:63:C9:4A:42:4A:18
Alternative Names

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=31536000
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
  • Increase HSTS max-age to at least 1 year and add includeSubDomains
  • 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)
Recommendations
  • Consider using critical flag (flags=128) for stricter CAA enforcement
  • You have authorized 5 CAs - consider limiting to only the CAs you actively use
  • Consider adding 'iodef' records to receive notifications about unauthorized certificate issuance attempts

Subject Alternative Names

2 domains