Open
Cached
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just now
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SECURITY SCORE
Certificate Information
Subject
CN=twentythree.com
Issuer
C=US, O=Certainly, CN=Certainly Intermediate R1
Valid From
January 13, 2026
Valid Until
February 12, 2026
26 days
Public Key
RSA
2048 bit
Adequate
Signature Algorithm
SHA256-RSA
SHA-256 Fingerprint
FF:3D:10:91:A8:AD:3C:D2:B9:97:A1:38:2E:3B:C0:49:92:4A:66:10:AE:4D:0D:77:5D:E2:83:29:39:FF:D2:5D
Alternative Names
Security Configuration
TLS Protocols
TLS 1.2
Forward Secrecy
Limited
(Check cipher configuration)
Warnings
- • TLS 1.3 is not supported (recommended)
HTTP Security Headers
Status
Strict-Transport-Security
Present
max-age=31536000
Content-Security-Policy
Missing
Not configured
X-Frame-Options
Missing
Not configured
X-Content-Type-Options
Good
nosniff
Referrer-Policy
Good
no-referrer-when-downgrade
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 X-Frame-Options: DENY or SAMEORIGIN to prevent clickjacking
- • 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 7 CAs - consider limiting to only the CAs you actively use
- • Consider adding 'iodef' records to receive notifications about unauthorized certificate issuance attempts
- • Consider adding 'issuewild' records to control wildcard certificate issuance