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SECURITY SCORE
Certificate Information
Subject
CN=exercism.org
Issuer
C=US, O=Google Trust Services, CN=WE1
Valid From
October 29, 2025
Valid Until
January 27, 2026
85 days
Public Key
ECDSA
256 bit
(P-256)
Adequate
Signature Algorithm
ECDSA-SHA256
SHA-256 Fingerprint
57:94:E1:D5:20:9C:21:A7:09:08:70:34:69:0F:6F:7F:F0:81:82:89:D4:75:75:5B:0D:BE:BB:4F:1F:43:6D:53
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
Good
max-age=63072000; includeSubDomains
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
- • Consider adding 'preload' to HSTS for maximum security
- • 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