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SECURITY SCORE
Certificate Information
Subject
CN=teachme.jp
Issuer
C=US, O=Amazon, CN=Amazon RSA 2048 M03
Valid From
July 28, 2025
Valid Until
August 24, 2026
264 days
Public Key
RSA
2048 bit
Adequate
Signature Algorithm
SHA256-RSA
SHA-256 Fingerprint
4D:DB:42:E1:24:BD:81:B5:44:BD:25:20:B7:33:A4:7D:BE:D6:4E:AF:A9:DE:EE:3A:6A:90:12:C4:2B:FB:76:02
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
Weak
frame-ancestors
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
- • Increase HSTS max-age to at least 1 year and add includeSubDomains
- • Significantly strengthen CSP directives
- • 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