DNS Gurus
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86/100 SECURITY SCORE

Certificate Information

Subject
CN=calendly.com
Issuer
C=US, O=Google Trust Services, CN=WE1
Valid From
October 14, 2025
Valid Until
January 12, 2026 70 days
Public Key
ECDSA 256 bit (P-256) Adequate
Signature Algorithm
ECDSA-SHA256
SHA-256 Fingerprint
22:51:7B:EE:46:25:4C:AC:A3:DF:92:A1:F8:6F:E8:B8:48:61:2A:2D:E6:AD:3E:DB:66:6A:E9:CC:1B:C8:BE:02
Alternative Names
4 domains

Security Configuration

TLS Protocols
TLS 1.2 TLS 1.3
Forward Secrecy
Supported (Modern clients use PFS)

HTTP Security Headers

Status
Strict-Transport-Security
Excellent
max-age=31536000; includeSubDomains; preload
Content-Security-Policy
Missing
Not configured
X-Frame-Options
Missing
Not configured
X-Content-Type-Options
Good
nosniff
Referrer-Policy
Missing
Not configured
Permissions-Policy
Missing
Not configured
Recommendations
  • • Add Content-Security-Policy header to prevent XSS attacks
  • • Add X-Frame-Options: DENY or SAMEORIGIN to prevent clickjacking
  • • 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
comodoca.com digicert.com ; cansignhttpexchanges=yes godaddy.com letsencrypt.org pki.goog ; cansignhttpexchanges=yes sectigo.com ssl.com amazon.com
Wildcard CAs
amazon.com comodoca.com digicert.com ; cansignhttpexchanges=yes godaddy.com letsencrypt.org pki.goog ; cansignhttpexchanges=yes sectigo.com ssl.com
Incident Reporting
Recommendations
  • • Consider using critical flag (flags=128) for stricter CAA enforcement
  • • You have authorized 8 CAs - consider limiting to only the CAs you actively use