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84/100 SECURITY SCORE

Certificate Information

Subject
CN=fly.io
Issuer
C=US, O=Let's Encrypt, CN=E7
Valid From
September 07, 2025
Valid Until
December 06, 2025 33 days
Public Key
ECDSA 256 bit (P-256) Adequate
Signature Algorithm
ECDSA-SHA384
SHA-256 Fingerprint
12:87:22:F6:18:32:80:8C:44:D6:75:70:43:C0:23:15:96:E2:6B:08:21:8F:C0:2E:F6:07:AA:47:B3:59:D0:A2
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
Missing
Not configured
Content-Security-Policy
Missing
Not configured
X-Frame-Options
Good
SAMEORIGIN
X-Content-Type-Options
Good
nosniff
Referrer-Policy
Good
strict-origin-when-cross-origin
Permissions-Policy
Missing
Not configured
Recommendations
  • Add Strict-Transport-Security header with max-age of at least 1 year
  • Add Content-Security-Policy header to prevent XSS attacks
  • 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

Subject Alternative Names

1 domain