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SECURITY SCORE
Certificate Information
Subject
CN=fastai.dev
Issuer
C=US, O=Let's Encrypt, CN=R12
Valid From
September 25, 2025
Valid Until
December 24, 2025
40 days
Public Key
RSA
4096 bit
Strong
Signature Algorithm
SHA256-RSA
SHA-256 Fingerprint
35:0B:88:8F:2E:D9:43:E1:E6:5E:84:74:B0:D0:34:67:5D:65:65:5D:3B:1B:0C:CF:42:4B:7F:34:9D:D9:B6:D0
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
Weak
upgrade-insecure-requests
X-Frame-Options
Missing
Not configured
X-Content-Type-Options
Missing
Not configured
Referrer-Policy
Missing
Not configured
Permissions-Policy
Missing
Not configured
Recommendations
- • Add Strict-Transport-Security header with max-age of at least 1 year
- • Significantly strengthen CSP directives
- • Add X-Frame-Options: DENY or SAMEORIGIN to prevent clickjacking
- • Add X-Content-Type-Options: nosniff
- • 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
Wildcard CAs
Recommendations
- • Consider using critical flag (flags=128) for stricter CAA enforcement
- • You have authorized 6 CAs - consider limiting to only the CAs you actively use
- • Consider adding 'iodef' records to receive notifications about unauthorized certificate issuance attempts